the Abstract book

Transcription

the Abstract book

High Resolution Spectroscopies
of Isolated Species:
present and future directions
In honor of the 80th birthday of Professor T. Darrah Thomas
HRSIS-2012
CONFERENCE
Satellite meeting of
SAINT-MALO
September 14-15, 2012
Synchrotron SOLEIL
SAINT-AUBIN, FRANCE
Chair:
Catalin MIRON
Scientific Program Committee:
Helena AKSELA
John D. BOZEK
Uwe HERGENHAHN
Robert LUCCHESE
Paul MORIN
Maria-Novella PIANCASTELLI
Kevin PRINCE
Jan-Erik RUBENSSON
Eckart RÜHL
Leif SAETHRE
Svante SVENSSON
Kiyoshi UEDA
CONFERENCE
Local Organizing Committee:
Clara BENAOUDIA
Florent CHAMBOISSIER
Frédérique FRAISSARD
Jean-Marc LUCACCHIONI
Christophe NICOLAS
Minna PATANEN
Isabelle QUINKAL
www.synchrotron-soleil.fr/Workshops/2012/HRSIS-2012
Affiche HR SIS 2012.indd 1
31/01/12 10:44:59
SPONS
SORS
T
Triangle de
e la Physiq
que
EXHIBITORS
V
VG SCIEN
NTA
R
RoentDek
ICESS 2012 Satellite Workshop
High-resolution spectroscopies of isolated species:
present and future directions - HRSIS-2012
September 14th - 15th, 2012,
Synchrotron SOLEIL
L’Orme des Merisiers, Saint-Aubin, France
Summary
• Scientific Committees
• Program
• Session I
• Session II
• Session III
• Session IV
• Session V
• Session VI
• Posters
• List of Participants
High-resolution spectroscopies of isolated species: present and future
directions - HRSIS-2012
th
In honor of the 80 birthday of Professor T. Darrah Thomas
September 14th - 15th, 2012
Synchrotron SOLEIL
L’Orme des Merisiers, Saint-Aubin, France
COMMITTEES
Chair:
Catalin MIRON
Synchrotron SOLEIL
Scientific Program Committee:
Helena AKSELA
John D. BOZEK
Uwe HERGENHAHN
Robert LUCCHESE
Paul MORIN
Maria-Novella PIANCASTELLI
Kevin PRINCE
Jan-Erik RUBENSSON
Eckart RÜHL
Leif SÆTHRE
Svante SVENSSON
Kiyoshi UEDA
Local Organizing Committee
Clara BENAOUDIA
Florent CHAMBOISSIER
Frédérique FRAISSARD
Jean-Marc LUCACCHIONI
Catalin MIRON
Christophe NICOLAS
Minna PATANEN
Isabelle QUINKAL
Dept. of Physics, Univ. of Oulu (Finland)
SLAC/LCLS (USA)
Max-Planck-Institute for Plasma Physics (Germany)
Dept of Chemistry, Texas A&M Univ.(USA)
Synchrotron SOLEIL (France)
LCP-MR (France)
Sincrotrone Trieste ScpA (Italy)
Dept. of Physics & Astronomy, Univ. Uppsala (Sweden)
Inst. für Physikalische Chemie (Germany)
Dept. of Chemistry, Univ. of Bergen (Norway)
Dept. of Physics & Astronomy, Univ. Uppsala (Sweden)
IMRAM, Tohoku University (Japan)
(Synchrotron SOLEIL):
High-resolution spectroscopies of isolated species: present and future directions HRSIS-2012
Program
Friday, 14th September
12:00 - 14:00
Registration and Welcome coffee
12:00 - 13:00
Lunch at SOLEIL restaurant
13:00 - 14:00
SOLEIL Tour (for registered participants)
14:00 - 14:15
Welcome by Catalin Miron
Session chair: M.N. Piancastelli
SESSION I
14:15 - 15:00
Electron spectroscopy and chemical properties past and present
L.J. Sæthre (Invited talk)
15:00 - 15:30
30 Years of electron spectroscopy with T. Darrah Thomas
T. Carroll (Invited talk)
15:30 - 15:45
Resonances in inner-shell photoemission from isolated endohedral systems
A.A. Pavlychev (Oral Communication)
15:45 - 16:00
A novel method to derive electronegativity from resonant inelastic X-ray scattering:
beyond Pauling, Mulliken and XPS scales
S. Carniato (Oral Communication)
16:00 - 16:30
Coffee break
Session chair: N. Mårtensson
SESSION II
16:30 - 17:00
Double core-hole spectroscopy – Experimental aspects
F. Penent (Invited talk)
17:00 - 17:30
Extracting chemical information of free molecules from K-shell double core-hole
spectroscopy: Theoretical aspects
K. Ueda (Invited talk)
17:30 - 18:00
High-resolution electron spectroscopy at the ALS – A new beginning
J.D. Bozek (Invited talk)
18:00 - 18:15
Photoemission of atoms and molecules studied with a VMI spectrometer
L. Avaldi (Oral Communication)
18:15 - 18:30
Multi electron coincidence spectroscopy of atomic mercury
J. Palaudoux (Oral Communication)
18:30 - 20:00
Poster Session and Cocktail
Saturday, 15th September
Session chair: P. Lablanquie
SESSION III
09:00 - 09:45
Recoil and related effects in molecular photoemission
E. Kukk (Invited talk)
09:45 - 10:15
Theory of rotational Doppler effect in X-ray photoionization
F. Gel’mukhanov (Invited talk)
10:15 - 10:45
High resolution molecular spectroscopy using electron-electron coincidence techniques
U. Hergenhahn (Invited talk)
10:45 - 11:15
Coffee break
Session chair: J.E. Rubensson
SESSION IV
11:15 - 11:45
Non Franck-Condon processes in molecular photoionization
E. Poliakoff (Invited talk)
11:45 - 12:15
Theoretical studies of the Non Born-Oppenheimer phenomena observed in molecular RAS and
RIXS spectroscopy
V. Kimberg (Invited talk)
12:15 - 12:30
Massive Franck-Condon breakdown investigated by vibrationally-resolved photoionization of
chiral molecules with circular-polarized light
L. Nahon (Oral Communication)
12:30 - 12:45
High-resolution angle-resolved Ro-vibrational autoionisation of ortho-D2 involving transitions
beyond the Born-Oppenheimer approximation
M. Siggel-King (Oral Communication)
12:45 - 14:00
Lunch at SOLEIL restaurant
Session chair: S. Svensson
SESSION V
14:00 - 14:30
A tale of resonant Auger spectroscopy seen (mostly) from the point of view of the N2 molecule
A. Kivimäki (Invited talk)
14:30 - 15:00
High-resolution Auger spectroscopy: A powerful tool to study metastable molecular dications
R. Püttner (invited talk)
15:00 - 15:30
Ultrafast dissociation: an unexpected tool for probing molecular dynamics
P. Morin (Invited talk)
15:30 - 16:00
Coffee Break
Session chair: K. Prince
SESSION VI
16:00 - 16:30
High energy structures in molecular photoionization
P. Decleva (Invited talk)
16:30 - 17:00
High-resolution electron spectroscopy: Cross sections and asymmetry parameters in complex
species
M. Patanen (Invited talk)
17:00 - 17:15
Accurate carbon 1s hole-state lifetimes for chlorinated methanes
M. Zahl (Oral Communication)
17:15 - 18:00
Conclusions by Prof. T. Darrah Thomas
SESSION I
Session chair: M.N. Piancastelli
IT-01
Electron spectroscopy and chemical properties past and present
L.J. Sæthre
IT-02
30 Years of electron spectroscopy with T. Darrah Thomas
T. Carroll
OC-01
Resonances in inner-shell photoemission from isolated endohedral systems
A.A. Pavlychev
OC-02
A novel method to derive electronegativity from resonant inelastic X-ray
scattering: beyond Pauling, Mulliken and XPS scales
S. Carniato
IT-01
Electron Spectroscopy and Chemical Properties
Past and Present
Leif J. Sæthre
Department of Chemistry, University of Bergen, NO-5007 Bergen, Norway
ABSTRACT
For more than 40 years, core-electron ionization energies have been the subject of
numerous experimental and theoretical investigations. One reason for this interest is that
these energies relate directly to properties of fundamental chemical significance such as the
charge distribution in a molecule, and the ability of a molecule to accept charge at a
particular site. These properties correlate with more familiar chemical properties such as
electronegativity, acidity, proton affinity, and reaction rates.[1-3] Of particular interest have
been carbon 1s ionization energies because of the rich and important chemistry of carbon
containing compounds. The combination of the high brightness of synchrotron radiation,
high-resolution electron analyzers, and the development of theoretical tools for analysis of
complex spectra, has made it possible to obtain chemical shifts of only a few 10´s of meV
between carbon atoms in large molecules. These results have provided insight into
substituent effects of a number of chemically significant molecules. [4-5] The talk will focus
on chemical properties obtained from gas-phase electron spectroscopy using both
conventional radiation sources of the past as well as the modern tools of the present.
REFERENCES
1.
2.
3.
4.
5.
L. J. Sæthre, T. D. Thomas, and O. Gropen, J. Am. Chem. Soc. 107, 2581-2585 (1985).
T. D. Thomas, M. R. F. Siggel, and L. J. Sæthre, J. Electron Spectrosc. Rel. Phenom. 51, 417-438 (1990).
L. J. Sæthre, T. D. Thomas and S. Svensson, J. Chem. Soc., Perkin Trans.2, 749-755 (1997).
M. G. Zahl, V. Myrseth, T. H. Andersen, J. Harnes, A. Borg, L. J. Sæthre, and K. J. Børve, J. Phys. Chem. 114, 15383-15393 (2010).
L. J. Sæthre, K. J. Børve, and T. D. Thomas, J. Electron Spectrosc. Rel. Phenom. 183, 2-9 (2011).
IT-02
30 Years of Electron Spectroscopy
with T. Darrah Thomas
Thomas X. Carroll
Keuka College, Keuka Park, NY, USA 14478
ASTRACT
During the last 40 + years Darrah Thomas has employed electron spectroscopy to investigate a
vast number of atomic and molecular systems. Whether by using a cylindrical-mirror analyzer
and aluminum K x-rays, electron-electron coincidence methods, or synchrotron-based systems,
the goals have always been the same: to determine useful and interesting chemical
information. This paper is a personal and scientific reflection on many of the achievements
attained during his rich and fascinating career.
OC-01
R
Resonances in
n Innerr-shell Photoe
emissiion from
Isolatted End
stems
dohedral Sys
X.O. Brykalovva and A.. A. Pavly
ychev
Stt. Petersburg
g State Unive
ersity, Uliano
ovskaia 1, Pe
eterhof, St. Petersburg,
P
1198504, Russ
sia
A
ABSTRACT
T
Mole
ecular electrronics is the subject o
of intriguing
g changes taking
t
placee when a molecule
m
happens to be con
nfined in a cage.
c
Whatt kind of ch
hanges are they? Answ
wering the question
q
we advvance in un
nderstanding
g of many elementary
y processes
s that occuur in biolog
gical and
complexx composite
e systems. Special em
mphasis is put
p here on unoccupieed valence states
s
of
a quasiffree molecu
ule that is co
onfined in fu
ullerenes. Our
O main atttention attraacts the end
dohedral
molecullar systemss such as M@C
M
@C240 and M@C540 where
w
M = C
CO, N2, SF
F6. X-ray
60, M@
absorpttion and inner-shell pho
otoionizatio
on spectra are
a regarded
d as a basicc probe of the
t cage
effects. Their origin
n is being attributed
a
m
mainly to (i) changes in molecular dynamics [1, 2], (ii)
intra- a
and inter-ele
ectron scatttering [3, 4
4] and (iii) intermolec
cular intera ction and dynamic
polariza
ability of the cage [5]. These ph
henomena as well as the effects
ts of electro
o-optical
propertiies of the ca
ages, their size and sh
hape on spe
ectral distrib
bution of osscillator stre
ength for
core-to--valence tra
ansitions in the
t endohe
edral system
ms are discu
ussed.
Re
esonances in photoemission fro
om CO,
N2, SF6 confined in icosahedral fulleren e shells
C60, C2240 and C540
are com
mputed witthin the
5
quasiato
omic approach. The
e resonancces are
comparred with the resonance
es in free ass well as
weakly bound CO, N2, SF6 mo
olecules
incorporated in molecularr (van-derr-Waals)
clusterss. Two limitiing cases of
o weak and
d strong
cage e
effects on the encap
psulated m olecular
units are revealed. Sha
ape reso
onances,
confinem
ment reson
nances and
d new wind
dow-like
resonan
nces in inn
ner-shell ph
hotoemissio
on from
the caged moleccules are revealed. Figure
presentts α) the window-like
resonance
w
e above
the S 1s egde in SF6@C240 (left panel)) and β)
the disstortion of the S 2p3/2 Æ 2t2gg shape
ecule in
resonan
nce in the encapsulate
e
ed SF6 mole
C240 (rig
ght panel). The cage effects on core-tovalence
e transitionss are discussed in more
e detail.
Figure The window-like rresonance jus
st above the S 1s
edge in SF
F6@C240 (left panel) and th
he S 2p3/2 Æ2t
Æ 2g
shape resonances in SF
F6@C240 (1) (right
(
panel). For
comparison the 2t2g resonnance in free SF
S 6 (2) is show
wn.
RE
ES
EFERENCE
1. R. Flessch, A. A. Pavlyychev, J. J. Neville, J. Blumberg
g, M. Kuhlmann, W. Tappe, F. Senf,
S
O. Schwarrzkopf, A. P. Hitchcock, and
E.Rühl, Phys. Rev. Lettt. 86, 3767-3770 (2001)
2. A. A. Pa
avlychev, R. Flessch, and E. Rühl, Phys. Rev. A, 770, 015201 (2004
4)
3. A. A. Pa
avlychev, X. O. Brykalova,
B
R. Fle
esch, and E. Rühhl. Phys. Chem. Chem.
C
Phys. 8, (2006) 1914 - 19221
4. A. A. Pavlychev, X. O. Brykalova,
B
D. A. Mistrov, R. Flessch, and E. Rühl.. J. Electron Spe
ectrosc. Relat. Phhenom. 166-167, (2008) 45 52
5. M. Ya. A
Amusia, J. Electtr. Spectrosc. Rellat. Phenom. 1599, 89 (2007)
OC-02
A Novel Method to Derive Electronegativity from
Resonant Inelastic X-ray Scattering :
Beyond Pauling, Mulliken and XPS scales
S. Carniato,†, L. Journel,†, R. Guillemin,†, M. N. Piancastelli,†,§,
W.C. Stolte,‡,∥, D. W. Lindle,‡,∥, and M. Simon,†
†
Laboratoire de Chimie Physique-Matière et Rayonnement, UMR 7614 du CNRS, Université Pierre et
Marie Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
§
Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
‡
Department of Chemistry, University of Nevada, Las Vegas, NV 89154-4003
∥Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720
ABSTRACT
The concept of electronegativity, the ability of an atom or functional group to attract
electrons to itself, plays an important role in chemistry.
Inner-shell ionization energies measured by X-ray Photoelectron Spectroscopy (XPS)
reflect both the charge distribution and polarizability (through the concept of hardness or
softness) of the molecule. It is not surprising therefore that core ionization energies of a
central atom are generally considered to correlate with the electronegativities of the
substituents attached to the atom. One pursuit by T. Darrah Thomas during his career has
been to use these correlations to obtain insight into the nature of electronegativity and to
develop methods for assigning group electronegativities on the basis of core binding
energies.
We present here a new method for deriving the chemical property electronegativity, which
was first described by Linus Pauling in 1932 [1]. The method is based on the modern
technique of Resonant Inelastic X-ray Scattering (RIXS), which is essentially an x-ray version
of Raman spectroscopy. Because the technique uses x-rays, RIXS is inherently an electronic
spectroscopy, unlike traditional Raman; the transitions being probed involve excitation of
core electrons in the sample.
For this work, we focused on chlorine-containing compounds. Based on an electron-density
analysis of the LUMO, the relative weights of the Cl 2pz atomic orbital contributing to the Cl
2p3/2 molecular spin-orbit components are
shown to yield a linear electronegativity scale
that is consistent with Pauling's fundamental
assumptions about the chemical bond.
Our measurements provide a direct and very
sensitive measure of the charge transfer
between the chlorine atom and any species
bound to it, in a way no other technique can do.
Importantly, the available experimental results
are enhanced by a theoretical model supported
by ab-initio calculations that agree very well
with the measured results, and also significantly
broaden the range of molecules in the study.
We will discuss how our results relate to
standard scales of electronegativity, e.g.
Mulliken/Pearson, Pauling and XPS.
REFERENCES
[1] Pauling, L., J. Am. Chem. Soc. 54, 3570 (1932)
SESSION II
Session chair: N. Mårtensson
IT-03
Double core-hole spectroscopy – Experimental aspects
F. Penent
IT-04
Extracting chemical information of free molecules from K-shell double corehole spectroscopy : Theoretical aspects
K. Ueda
IT-05
High-resolution electron spectroscopy at the ALS – A new beginning
J.D. Bozek
OC-03
L. Avaldi
OC-04
Multi electron coincidence spectroscopy of atomic mercury
J. Palaudoux
IT-03
Double Core-hole Spectroscopy
Experimental Aspects
F. Penent1, P. Lablanquie1, J. Palaudoux1, L. Andric1, P. Selles1,
S. Carniato1, M. Žitnik2, T.P. Grozdanov3, E. Shigemasa4, K. Soejima5,
Y. Hikosaka5, I. H. Suzuki6, M. Nakano6 and K. Ito6
1 LCP-MR, CNRS & Université P. VI, 11 rue P. et M. Curie, 75231 Paris Cedex 05, France
2 Jožef Stefan Institute, P. O. Box 3000, SI-1001 Ljubljana
3 Institute of Physics, University of Belgrade, Pregrevica118, 11080 Belgrade, Serbia
4 UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5 Department of Environmental Science, Niigata University, Niigata 950-2181, Japan
6 Photon Factory, Institute of Materials Structure Science, Oho, Tsukuba 305-0801, Japan
ABSTRACT
Although the interest of molecular double core hole states (DCHs) for ESCA (Electron
Spectroscopy for Chemical Analysis) was pointed out 25 years ago [1], their observation has
been possible only very recently, thanks to the development of two different approaches:
two-photon double-core ionization using XFEL sources [2] or single photon double-core
ionization using synchrotron sources [3,4]. We have demonstrated that the latter method
provides detailed information on the spectroscopy and decay dynamics of DCHs, even if the
associated double photoionization cross section is extremely weak. We have observed
single-site DCHs, (ss-DCHs: K-2) where the two core holes are created on the same atom of
the molecule [3], and also two-site DCHs, (ts-DCHs: K-1K-1), where the two core holes are on
different atoms [4].
The experiments were performed at Photon Factory (Japan) and at SOLEIL (France),
during single-bunch operation, using a magnetic bottle time-of-flight spectrometer. We have
studied simple molecules: N2, O2, CO, CO2 and C2H2n (n= 1, 2, 3).
By detecting in coincidence two photoelectrons with one or two Auger electrons, we have
characterized K-2 and K-1K-1 states: their binding energies, their respective Auger decay paths
and their relative intensity with respect to K-1 single ionization. Single photon double
ionization leading to K-2 states represents a ~10-3 fraction of single K-shell ionization, this
figure drops to ~10-5 for K-1K-1 states formation. A simple collisional knock-out model, where
an initially ionized K-shell electron hits and ejects a second K-shell electron from the
neighboring atom accounts for this ratio.
These experimental results are important to understand the formation of DCHs by single
photon absorption. The spectroscopy and the decay mechanisms of these highly excited
species are obtained with high accuracy.
We will present at the workshop our most recent results on photon double K-shell
ionization.
REFERENCES
[1] L. S. Cederbaum et al., J. Chem. Phys. 85, 6513 (1986).
[2] N. Berrah et al., Proc. Natl. Acad. Sci. U.S.A. 108, 16912 (2011)
[3] P. Lablanquie et al., Phys. Rev. Lett. 106, 063003 (2011).
[4] P. Lablanquie et al., Phys. Rev. Lett. 107, 193004 (2011).
IT-04
Extracting Chemical Information of Free Molecules
from K-shell Double Core-hole Spectroscopy :
Theoretical Aspects
Kiyoshi Ueda
Institute of Multidisciplinary Res. for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
ABSTRACT
Double core hole (DCH) states were investigated extensively in 70’s and 80’s using corecore-core type Auger spectroscopy. One of the major players was T.D. Thomas [1]. K-shell
DCH states, however, could not be studied by this approach, though these states, especially
those with core holes at two different sites, are of particular interest due to high chemical
sensitivity as illustrated theoretically by Cederbaum et al [1] and Ågren et al [2]. Emergence
of new light sources such as X-ray free electron lasers and developments of multi-electron
detection techniques using synchrotron radiation invoked renewal of interest in the K-shell
DCH spectroscopy as a tool for chemical analysis of free molecules and a series of both
theoretical [3-8] and experimental [9-11] works on the K-shell DCH spectroscopy have been
reported in the last few years.
The present talk will illustrate how to extract the chemical information out of the DCH
spectroscopy, using calculated ionization potential (IP) for K-Shell single core hole creation
and double ionization potential (DIP) for K-Shell double core hole creation for various
molecules. Quantities that can be extracted from the DCH spectroscopy (i.e. the
measurements for IP and DIP) are the relaxation energies as a measure of the electron
density flow to the core-hole site and the interatomic relaxation energies as a measure of the
electron density flow to the two core-hole sites. We find the following rule of thumbs. The
interatomic relaxation energy for the DCH states having two holes at adjacent two atoms
decreases with increasing in the bond order between the two atoms. The substitution of the
hydrogen atoms by the fluorine atoms affects the initial-state-bonding shifts but less
influences the relaxation energy. For DCH states having two holes at distances, the
interatomic relaxation energy decreases with increasing in the hole-hole distance.
The present theoretical work is in collaboration with O. Takahashi, M. Tashiro and M.
Ehara and supported in part by MEXT.
REFERENCES
1. T. D. Thomas, J. Electr. Spectrosc. Relat. Phenom. 20, 117 (1980).
2. L. S. Cederbaum et al, J. Chem. Phys. 85, 6513-6523 (1986); ivid. 86, 2168 (1987).
3. H. Ågren and H. J. A. Jensen, Chem. Phys. 172, 45-57 (1993).
4. R. Santra et al, Phys. Rev. Lett., 103, 013002 (2009); N. V. Kryzhevoi et al, J. Chem. Phys. 135, 084302 (2011).
5. M. Tashiro et al, J. Chem. Phys. 132, 184302 (2010); Chem. Phys. Lett. 496, 217 (2010); J. Chem. Phys. 135, 154307 (2011); Chem.
Phys. Lett. 521, 45 (2012).
6. O. Takahashi, et al, J. Phys. Chem. A 115, 12070-12082 (2011); Chem. Phys. 384, 28 (2011); Chem. Phys. Lett. 518, 44 (2011).
7. T. D. Thomas, J. Phys. Chem. A 116, 3856-3865 (2012).
8. K. Ueda and O. Takahashi, J. Electron Spectrosc. Relat. Phenom. Published on line [DOI: 10.1016/j.elspec.2012.04.003].
9. L. Fang et al, Phys. Rev. Lett. 105, 083005 (2010); N. Berrah et al, PNAS 108, 16912 (2011); P. Salén et al, Phys. Rev. Lett. Phys.
Rev. Lett. 108, 153003 (2012).
10. J. H. D. Eland et al, Phys. Rev. Lett. 105, 213005 (2010).
11. P. Lablanquie et al, Phys. Rev. Lett., 106, 063003 (2011); ivid. 107, 193004 (2011).
IT-05
High-resolution Electron Spectroscopy at the ALS
A New Beginning
John D. Bozek
LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 USA
ABSTRACT
The power of photoelectron spectroscopy to expand our knowledge about the nature of
atoms and molecules is limited by the capabilities of the light source used to photoionize the
sample, those of the electron spectrometer used to separate the energies of the resulting
electrons, and the knowledge and imagination of the scientists controlling those instruments.
A fortunate confluence of a new light source, a new electron spectrometer and a seasoned
veteran scientist came together in Berkeley in the mid 1990’s.
New x-ray light sources and their expanded capabilities lead to a more detailed
understanding of the atomic and molecular world. With the advent of a 3rd generation light
source, the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory, the
power of undulator radiation from a machine designed to deliver a bright electron beam,
allowed high dispersion monochromators to be routinely used. Undulator sources were key,
allowing such beamlines to deliver enough flux to perform photoelectron spectroscopy on
gaseous samples with sufficient resolution to routinely resolve the vibrational structure of
valence and shallow core electronic levels over a wide energy range.
Simultaneously, the Scienta company made high-resolution photoelectron spectrometers
with millielectron volt resolution over a wide range of kinetic energies commercially available,
something that was previously only possible with specialized instruments developed in-house
by expert electron spectroscopists. While some vibrationally resolved C 1s photoelectron
spectra of molecules had been published previously from experiments done at 2nd generation
synchrotron light sources, for example, it was now possible to resolve the vibrational
structure in a wide variety of hydrocarbons and study chemical and substituent effects.
The final piece of the puzzle was someone with the breadth of knowledge to identify
important chemical problems that could be solved using these new capabilities and the
experience to accomplish these studies. At the ALS, we were fortunate enough to find those
key elements in Darrah Thomas, a professor from the adjacent state of Oregon, and lured
him down to perform excellent science using the novel capabilities of the newly constructed
light source.
I will talk about some of Darrah’s work using the ALS and contrast it with previously
published work. Darrah stands as an example to all of us about how a scientist with a good
knowledge of his subject can be ready to exploit new capabilities that arise from the steady
progress in technology and use them to further our understanding of the world around us
OC-03
Photoemission of Atoms and Molecules Studied
with a VMI Spectrometer
P. O’Keeffe1, P. Bolognesi1, R. Richter2, A. Moise2, A. Mihelič3,
M. Žitnik3 and L. Avaldi1
1
CNR-Istituto di Metodologie Inorganiche e dei Plasmi, Area della Ricerca di Roma 1,
CP, 00016 Monterotondo Scalo, Italy
2
Sincrotrone Trieste SCpA, Area Science Park, I-34149 Basovizza (Trieste), Italy
3
Jožef Stefan Institute, Jamova cesta, 39, SI-1000 Ljubljana, Slovenia
ABSTRACT
Measurements of the photoelectron angular distributions (PADs) in the photoionization of
atoms and molecules have long been known as a valuable tool to characterize the structure
of the continuum and bound electronic states, to provide information on photoionization
dynamics and to test theoretical models. Renewed interest in the measurement of PADs has
been triggered by the development of new highly efficient imaging detectors [1].Recently the
branch line of the GasPhase beamline has been equipped with a mode-locked Ti:Sapphire
oscillator (Tsunami, Spectra Physics) [2] and a velocity map imaging (VMI) [3].
The high efficiency in the detection of low energy electrons of this set-up has been
exploited to study the two-photon resonant photoionization of He and Ne, the near threshold
photoionization of rare gases in the valence and inner shell, the near threshold
photoionization of nitrogen and the ICD decay of inner shell excited dimers (Ar2, NeAr, KrAr) .
Photoelectron angular distribution of He obtained exciting the 1s5p 1P1 state with synchrotron radiation
(24.046 eV) and ionizing with laser radiation (699.85 nm -1.772 eV). The left part of the figure
contains the raw image, while the right part shows the inverted image.
REFERENCES
1.°°A.T Eppink and J.B. Parker Rev. Sci. Instrum. 68 3477 (1997)
2.°°A. Moise et al. Nucl. Instrum. Meth. A 588 502 (2008)
3. P. O’Keeffe et al. Rev. Sci. Instrum. 82 033109 (2011)
OC-04
Multi Electron Coincidence Spectroscopy
of Atomic Mercury
J. Palaudoux1, M. Huttula2, S.-M. Huttula2, P. Lablanquie1,
L. Andric1 and F. Penent1
1
LCP-MR, Université Pierre et Marie Curie, Paris VI and CNRS (UMR 7614)
11 rue P. et M. Curie, 75231 Paris Cedex 05, France
2
Department of Physical Sciences, P.O. Box 3000, 90014 University of Oulu, Finland
ABSTRACT
Electron spectroscopy is a well-established method to study electronic structure in
various forms of matter. Presently, third generation synchrotron radiation sources and multielectron coincidence setups are common tools for experimentalists. We have developed a
magnetic bottle type multi-coincidence spectrometer, HERMES, and we have used it to study
multiple Auger processes in various rare gas atoms [1] and in small molecules [2].
Electron coincidence studies of core ionization of metal atoms by synchrotron
radiation are still scarce. We have studied the electronic transitions in vapor phase atomic Hg
([Kr]5s25p64f145d106s2), where 5d and 6s can be considered as valence orbitals as they do
not Auger decay. Our previous investigation dealt with the spectroscopy of triple and
quadruple ionized states of mercury produced by multiple Auger decay [3]; we detail here
those various Auger processes. The experiments were carried out on the PLEIADES beam
line at SOLEIL synchrotron. The recorded sets of coincidence events reveal various single
and multiple electron transitions. The Auger decay channels of the spin-orbit split 4f5/2,7/2 and
5p1/2,3/2 core holes as well as that of the 4f satellite components are resolved individually. An
unexpectedly strong core(4f)-valence direct-like double ionization is observed and assigned
to the very rapid (<100as) Coster Kronig decay of the 5s level. Relativistic Multiconfiguration
Dirac Fock calculations have been performed to predict the spectral features and are in very
good agreement with the experimental findings.
Second electron energy (eV)
80
Figure: Bottom shows the Hg photoelectron spectrum with
the main 4f and 5p inner shell lines. Top displays the energy
correlation map between electron pairs; it visualizes the
Auger decay of the different inner shell holes, and a core
valence double ionisation path (CV). The faint diagonal line
on the right corresponds to the valence double ionisation
path (DPI). A 250eV photon energy was used.
60
40
20
CV
3
Counts (x10 )
DPI
0
20
15
10
5
0
4f5/2
4f sat
80
100
4f7/2
5p1/2
120
140
160
Photoelectron energy (eV)
5p3/2
180
200
REFERENCES
1. F. Penent et al., PRL 95, 083002 (2005). J. Palaudoux et al., PRA 82, 043419 (2010). P.Lablanquie et al., PCCP 13, 18355 (2011).
2. T. Kaneyasu et al., PRL 101, 183003 (2008). F. Penent et al., PRL 106, 103002 (2011).
3. M. Huttula et al., PRA 83, 032510 (2011).
SESSION III
Session chair: P. Lablanquie
IT-06
Recoil and related effects in molecular photoemission
E. Kukk
IT-07
F. Gel’mukhanov
IT-08
High resolution molecular spectroscopy using electron-electron coincidence
techniques
U. Hergenhahn
OC-05
Photon energy dependent crossections in the photoionization of gaseous
molecular oxygen
J. Söderström
IT-06
Recoil and Related Effects
in Molecular Photoemission
E. Kukk1, K. Ueda2 and C. Miron3
1
Dept. of Physics and Astronomy, University of Turku, FIN-20014 Turku, Finland
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University,
Sendai 980-8577, Japan
3
Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48,
FR-91192 Gif-sur-Yvette Cedex, France
2
ABSTRACT
Since the invention of ESCA in 1960's, photoelectron spectroscopy has been an
invaluable tool for physical chemistry and chemical physics for investigating many key
properties of single molecules. Advances in the techology of electron energy analyzers as
well as synchrotron radiation sources over last decades have made it possible to perform
electron spectroscopy of even very low density targets in gas phase with very high
spectroscopic quality1. This, combined with advanced analysis methods has allowed to
investigate the properties of molecular photoemission with unprecedented accuracy.
We focus on the vibrational and rotational structure in molecular photoemission, as
studied by means of high-resolution electron spectroscopy and analyzed by least-squares
decomposition methods in combination with theoretical models ranging from simple semiclassical models to advanced scattering theory. It has been a broadly accepted view in the
community that, at energies well above the ionization thresholds, one reaches a region
where the intensities of the vibrational excitations are determined only by the squares of the
overlap integrals of the pre- and post-ionization nuclear wavefunctions, the Franck-Condon
factors. Since the beginning of this millenium, however, a number of phenomena were
identified that drastically change this view. Recoil, scattering and intereference effects have
all been shown to influence the structure of the molecular photoelectron spectra at all
ionization energies so that there is no pure "Franck-Condon regime”. We consider the basis,
manifestations and consequences (particularly in respect to the various branching ratios that
can be determined from experimental photoelectron spectra) of the following phenomena:
•
•
•
•
Vibrational recoil2
Rotational recoil and Doppler broadening3
Cohen-Fano (two-center) interferences4
Photoelectron scattering on neighboring5.
All the above-considered effects can be incorporated into a unified quantum mechanical
treatment. The above-described phenomena are not only a fruitful testing ground for
quantum mechanical theories and numerical calculations, but can potentially lead to methods
for probing the geometrical parameters of single molecules that are more complex and less
known than the cases studied so far.
REFERENCES
1. C. Miron and P. Morin, High-Resolution Inner-Shell Photoionization, Photoelectron and Coincidence Spectroscopy, in
Handbook of High-Resolution Spectroscopy, Vol 3, ed.M. Quack and F. Merkt, John Wiley&Sons Ltd, p. 1655 (2011).
2. E. Kukk et al., Physical Review Letters 95, 133001 (2005).
3. T.D. Thomas, et al., The Journal of Chemical Physics 133, 174312 (2010).
4. X. Liu et al., Journal of Physics B: Atomic, Molecular and Optical Physics 39, 4801 (2006).
5. E. Plésiat et al., Physical Review A 85, 023409 (2012).
IT-07
Theory of Rotational Doppler Effect
in X-ray Photoionization
Faris Gel’mukhanov
Theoretical Chemistry, Royal Institute of Technology, S-106 91 Stockholm, Sweden
ABSTRACT
The Doppler effect for electromagnetic waves is of great use in astronomy, meteorology etc.
The measuring of the Doppler broadening of spectral lines gives us the temperature of plasma
and remote cosmic objects. Conventional motional broadening of X-ray photoelectron (XPE) line
of valence ionization is attributed to the fundamental physical phenomenon-translational
electronic Doppler effect which is direct analogy of the photon Doppler effect. The translational
Doppler broadening being fully defined by the mass of the molecule and the temperature is the
same fo all spectral lines of rarified gas. However, recently was predicted [1] that the XPE line
is strongly affected by the rotational Doppler broadening which is of the same order of
magnitude as its translational counterpart. Very soon, this effect was nicely confirmed in XPE
experiment with the nitrogen molecule [2]. Both the theory and the experiment say
unambiguously that the spectral shape of the XPE line should be revised. Indeed, nevertheless
of similarity of two Doppler effects, there is qualitative difference. Contrary to the translational
Doppler shift, the rotational Doppler shift being proportional to the angular recoil momentum is
very sensitive to the direction of ejection of photoelectron relative to molecular axis. This makes
the rotational Doppler broadening different for different final cationic states and polarization of Xrays. Our calculations being in good agreement with the experimental data confirm nicely this
expectation.
REFERENCES
1.
2.
Yu-Ping Sun et al., Phys.Rev. A 82, 052506 (2010).
Thomas T. D. et al., Phys. Rev. Lett. 106, 193009 (2011).
IT-08
High Resolution Molecular Spectroscopy using
Electron-electron Coincidence Techniques
U. Hergenhahn1, T. Arion1,2, V. Ulrich1, R. Püttner3, C. Lupulescu4,
R. Ovsyannikov5, G. Öhrwall6, A. Lindblad7, S. Svensson7,
A. M. Bradshaw8, W. Eberhardt9
1
Max-Planck-Institute for Plasma Physics, EURATOM Association, 17491 Greifswald, Germany
Institut für Experimentalphysik, Uni Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
3
Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
4
TU Berlin, Institut für Optik und atomare Physik, Hardenbergstr. 36, 10623 Berlin, Germany
5
Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489 Berlin, Germany
6
MAX-lab, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
7
Uppsala University, Department of Physics and Astronomy, Box 516, SE-751 20 Uppsala, Sweden
8
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
9
Center for Free-Electron Laser Science, Notkestrasse 85, 22607 Hamburg, Germany
2
ABSTRACT
Sufficient photon energy provided, photoionization can easily result in the loss of two or
more electrons from a molecule. This can be due either to a simultaneous ejection of two
electrons (direct photo double ionization) or due to autoionization of the ion that is primarily
produced (Auger decay, ICD). A complete characterization of these processes is only
possible when both emitted electrons are recorded in coincidence.
In this talk, I will review experiments on molecular inner shell photoionization, followed by
Auger decay, in which both of the emitted electrons have been recorded with high energy
resolution. This allows to record Auger spectra, which are specific to a certain component of
an inner shell ionized state, e.g. a single vibrational substate, or one selected spin-state
within a multiplet. The additional information thus gained can be used to better characterize
the molecular potential curves in play.
Carbon monoxide,1 oxygen,2,4 methane3 and fluorinated hydrocarbon molecules will be
presented as examples.
Technically, our set-up is based on a combination of time-of-flight (TOF) electron spectroscopy with a conventional hemispherical analyser. A first version used simple, linear timeof-flight analysers.2 It has now been superseded by one employing a novel angle-resolving
TOF spectrometer (ArTOF).4 Perspectives and limitations of this set-up, and its merits with
respect to other coincidence detection schemes, will be discussed.
For molecules with metastable dicationic states, the excess energy gained in the photoionization process is transferred to kinetic energy of the two emitted electrons, plus a fixed
final state energy. Detecting both electrons by our coincidence technique might thus finally
allow to break the resolution barrier of natural (lifetime) broadening in inner shell photoelectron spectroscopy.
REFERENCES
1. V. Ulrich, S. Barth, S. Joshi, T. Lischke, A.M. Bradshaw, and U. Hergenhahn, Phys. Rev. Lett. 100, 143003 (2008).
2. V. Ulrich, S. Barth, T. Lischke, S. Joshi, T. Arion, M. Mucke, M. Förstel, A.M. Bradshaw, and U. Hergenhahn, J. Electron Spectrosc.
Relat. Phenom. 183, 70 (2011).
3. R. Püttner, T. Arion, M. Förstel, T. Lischke, M. Mucke, V. Sekushin, G. Kaindl, A.M. Bradshaw, and U. Hergenhahn, Phys. Rev. A 83,
043404 (2011).
4. T. Arion, R. Püttner, C. Lupulescu, R. Ovsyannikov, M. Förstel, G. Öhrwall, A. Lindblad, K. Ueda, S. Svensson, A.M. Bradshaw, W.
Eberhardt, and U. Hergenhahn, J. Electron Spectrosc. Relat. Phenom. in print.
OC-05
Photon Energy Dependent Crossections in the
Photoionization of Gaseous Molecular Oxygen
J. Söderström1, O. Travnikova2, A. Lindblad1,
S. Svensson1 and C. Miron2
1. Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala, Sweden
2. Synchrotron SOLEIL, l’Orme des Merisiers, Saint-Aubin, BP 48,
91192 Gif-sur-Yvette Cedex, France
ABSTRACT
Many molecules in the gas phase exhibit so-called shape resonances, where the photoionization crossection varies significantly near the ionization threshold. The origin of shape
resonances has been well understood and today they are no longer a theoretical problem.
Recently it has been shown that the shape resonances are a part of a larger intra-molecular
scattering phenomena, which probably will lead to a greater understanding of this
phenomenon in the coming years.
In molecular oxygen it has generally been believed that the photo ionization crossection has
no shape resonance, that it is “pushed below” the ionization potential by the sigma
resonance. We have investigated both the photoemission as well as the Auger decay as a
function of the photon energy in the range 550 – 600 eV. In these experiments the
polarization vector of the ionizing photons were both horizontal (LH) and vertical (LV) with
respect to the axis of detection of the emitted electrons, this allows us to not only draw
conclusions about the ionization crossection, but also the angular distribution of
photoelectrons.
A striking effect in the measured spectra is that the intensity ratios in the (normal) Auger
spectra are not constant as a function of photon energy, see Fig. 1. Furthermore the Auger
spectra measured with LH and LV polarization are not identical indicating that the Auger
transition is not only a monopole transition, as expected, but partly also a dipole transition,
see Fig. 2. A detailed analysis of the photoemission spectra will also be presented together
with these findings.
Figure 1. The normal Auger spectra of gaseous O2 measured
in both LV and LH polarization. The energy scale is not
calibrated and the relative intensity is normalized on the peak
at 493.5 eV. The differences for high kinetic energies could be
a sign of a shape resonance in gaseous O2.
Figure 2. The normal Auger spectra of gaseous O2 measured at a
photon energy of 600 eV for both LH and LV polarization. The energy
scale is not calibrated and the relative intensity is normalized on the
peak at 493.5 eV. Small differences for high kinetic energies are seen
indicating that the Auger transition is not necessarily strictly a
monopole transition.
SESSION IV
Session chair: J.E. Rubensson
IT-09
Non Franck-Condon processes in molecular photoionization
E. Poliakoff
IT-10
Theoretical studies of the non Born-Oppenheimer phenomena observed in
molecular RAS and RIXS spectroscopy
V. Kimberg
OC-06
Massive Franck-Condon breakdown investigated by vibrationally-resolved
photoionization of chiral molecules with circular-polarized light
L. Nahon
OC-07
High-resolution angle-resolved Ro-vibrational autoionisation of ortho-D2
involving transitions beyond the Born-Oppenheimer approximation
M. Siggel-King
IT-09
Non Franck-Condon Processes
in Molecular Photoionization
Erwin D. Poliakoff
Department of Chemistry, Louisiana State University, Baton Rouge, LA 70808 USA
ABSTRACT
Photoionization is a special case of electronic spectroscopy, and a cornerstone of
molecular electronic spectroscopy is the Franck-Condon approximation, which states that
electronic and vibrational motion can be evaluated independently. However, early work in
photoelectron spectroscopy showed that violations of the Franck-Condon approximation are
relatively common. Such violations are typically manifested in vibrational structures that
depend on the incident photon energy, thereby indicating a coupling between the vibrational
and photoelectron motion. While it is typically assumed that deviations are due to
resonances, and thus relatively narrow in energy, recent results have demonstrated that
deviations can be widespread.1-3 Current studies are demonstrating a variety of reasons for
such global deviations from Franck-Condon expectations. Equally important, studies have
shifted to more complex polyatomic molecular systems that have alternative vibrational
degrees of freedom, and allow greater power in probing coupling between electronic and
vibrational degrees of freedom for specific vibrational deformations.4 We will discuss
mechanisms responsible for broad range coupling between vibration and photoelectron
motions, and also describe the sources of mode-specific vibrational responses. Finally, the
connections with emerging topics in molecular physics will be discussed, with an emphasis
on high harmonic generation in molecular media.
REFERENCES
1. R.M. Rao, E.D. Poliakoff, K.Wang, and V. McKoy, Phys. Rev. Lett. 76, 2666 (1996).
2. T. D. Thomas, E. Kukk, R. Sankari, H. Fukuzawa, G. Pruemper, K. Ueda, R. Puettner, J. Harries, Y. Tamenori, T. Tanaka, M.
Hoshino and H. Tanaka, J. Chem. Phys, 128 144311 (2008).
3. S. E. Canton, E. Plesiat, J. D. Bozek, B. S. Rude, P. Decleva and F. Martin, Proc. Nat. Acad. Sci. 108, 7302 (2011).
4. A. Das, J.S. Miller, E.D. Poliakoff, R.R. Lucchese, and J.D. Bozek, J. Chem. Phys. 131, 044311 (2009).
IT-10
Theoretical Studies of the Non Born-Oppenheimer
Phenomena Observed in Molecular
RAS and RIXS Spectroscopy
Victor Kimberg
Max Planck Advanced Study Group at CFEL, DESY, Notkestr. 85, 22607 Hamburg, German
Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
ABSTRACT
Born-Oppenheimer (BO) and Franck-Condon (FC) approximations are two major concepts
in the interpretation of electronic excitations and modeling of spectroscopic data in molecular
systems. The FC principle states that the transition dipole moment is independent of the
nuclear coordinates for the considered vibronic transition, although it is not applicable when
the final state changes its character within the vibrational region of the initial state. More
general than the FC, the BO approximation allows for geometry dependence of the matrix
element describing the electronic transition, but it breaks down when the total wave function
cannot be factorized anymore into a product of electronic and nuclear wave functions due to
mixing of several electronic states.
A well known situation of the BO approximation breakdown is the crossing of potential
energy curves, when the non-BO dynamics arises from the vibronic coupling between the
electronic states. In the case of the resonant x-ray scattering another reason for the BO
approximation breakdown is the interference of the quantum pathways leading to the same
molecular state and thus coupling the nuclear dynamics in the intermediate and final
electronic states. Moreover, quite often both breakdown mechanisms are present resulting in
a complex non-BO behavior, which is detectable nowadays by the ultra-high resolution x-ray
spectroscopies.
Already diatomic molecules like O2 may exhibit interesting behavior related to the nonadiabatic coupling between Rydberg and valence core-excited states [1, 2] and interchannel
interference [2, 3], while simple polyatomic molecules like C2H2 show nontrivial anisotropy
properties resulting from the Renner-Teller [4] and various interference effects [5]. In the
present talk we will discuss the non-BO phenomena observed in the resonant x-ray
scattering from the small gas-phase molecules using ab initio calculations of the electronic
structure combined with the time-dependent description of the vibrational wave packet.
REFERENCES
1.
2.
3.
4.
5.
Y. Velkov, V. Kimberg, N. Kosugi, P. Salek, and F. Gel’mukhanov, Chem. Phys. Lett. 476, 147 (2009).
V. Kimberg, T. Gejo, M. Oura, T. Tokushima, Y. Horikawa, H. Arai, S. Shin, and N. Kosugi, Phys. Rev. A 85, 032503 (2012).
A. Lindblad, V. Kimberg, C. Nicolas, J. Söderström, O. Travnikova, N. Kosugi, F. Gel’mukhanov, and C. Miron, submitted (2012).
V. Kimberg, N. Kosugi, and F. Gel'mukhanov, J. Chem. Phys. 130, 114302 (2009).
C. Miron, V. Kimberg, P. Morin, C. Nicolas, N. Kosugi, S. Gavrilyuk, and F. Gel’mukhanov, Phys. Rev. Lett. 105, 093002 (2010).
OC-06
Massive Franck-Condon Breakdown Investigated by
Vibrationally-resolved Photoionization of Chiral
Molecules with Circular-polarized Light
L. Nahon,1 G. Garcia,1 S. Daly2 and I. Powis2
1
Synchrotron SOLEIL, l’Orme des Merisiers, Saint Aubin BP 48,
91192 Gif sur Yvette Cedex, France
2
School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK
ABSTRACT
One of the assumption of the Franck-Condon (FC) approximation is that transition matrix
elements governing a given electronic transition do not depend on the nuclear geometry
sampled during vibrational motion. In the case of molecular photoionization, FC breakdown
has been observed along shape resonances, which are known to be very sensitive to
geometries. Recently, Jahnke et al.1 reported a vibrational-dependence in the Molecular
Frame Photoelectron Angular Distributions (MF-PADs) observed from C (1s-1)
photoionization of fixed-in-space CO molecules by Circularly Polarized Light (CPL), far from
any shape resonances, showing the high sensitivity of MF-PADs to photoelectron scattering
by the molecular potential. This information is in general lost in the averaging due to the
random orientation in the laboratory frame.
On the other hand, Photoelectron Circular Dichroism (PECD) as observed by an intense
forward/backward asymmetry in the laboratory-frame PADs produced by the CPL-induced
ionization of a randomly oriented pure enantiomer,2 has proven to be also a very sensitive
probe of the molecular potential, especially for slow electrons.3 In this context, by using
electron imaging techniques, well adapted to slow electrons, we have measured the
vibrationally-resolved PECD of pure enantiomers of methyloxirane, within the first eV above
the IP, a region unaffected by any shape resonance.
A massive FC breakdown is observed with the change and even the reversal of the
forward/backward asymmetries according to the cation vibrational mode excited.4 A simple
yet realistic model calculation is used to develop understanding of this phenomenon, which is
ascribed to the high sensitivity of PECD to scattering phase off the molecular potential, and
consequently to the vibrationally averaged nuclear geometry sampled in the photoionization
process. PECD appears therefore to offer a powerful, and (for chiral species) universally
applicable probe of vibration dynamics in molecular photoionization, even from randomlyoriented targets.
REFERENCES
1.
2.
3.
4.
T. Jahnke et al., Phys. Rev. Lett. 93, 083002 (2004).
I. Powis, Adv. Chem. Phys. 138, 267-329 (2008).
L. Nahon and I. Powis, "Valence-shell PECD" in Chiral recognition in the gas phase, edited by A. Zehnacker, Boca Raton: Taylor &
Francis, 2010, pp. 1-26
G. Garcia, L. Nahon, S. Daly, and I. Powis, Phys. Rev. Lett. (submitted).
OC-07
High-resolution Angle-resolved Ro-vibrational
Autoionisation of Ortho-D2 Involving Transitions
beyond the Born-Oppenheimer Approximation
M.R.F. Siggel-King1, E. Sokell2, A.M. Juarez3, P. Bolognesi4,
G.C. King5 and E. Weakick2
1
Cockcroft Institute, Daresbury Science and Innovation Campus, Daresbury, Warrington, WA4 4AD,
UK and the Department of Physics, University of Liverpool, UK
2
School of Physics, University College Dublin, Belfield, Dublin 4, Ireland
3
Universidad Nacional Autónoma de México, Av. Universidad S/N, Cuernavaca, Mor. México
4
CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo, Italy
5
School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
ABSTRACT
Rotationally-resolved photoelectron spectra for several of the lowest vibrational levels of
H2+ have been measured previously at fixed photon energies provided by HeI and NeI
discharge lamps [1]. However, none of these experiments showed evidence of a rotational
transition with ΔN = N+ - N = 4, between the initial neutral and final ionic states with rotational
quantum numbers N and N+ respectively. Transitions with ΔN = 4 only occur if there is f-wave
emission. Previously such a possibility had been ruled out on the basis of the approximation
of near-conservation of angular momentum. More recent experiments have made use of the
variable photon energy and high photon flux provided by second-generation synchrotron
sources to obtain photoelectron spectra near the ionisation threshold of H2 [2]. However,
these also showed no evidence of transitions with changes of rotational quantum number ΔN
= 4.
Subsequently, we reported the first observation of a change of ΔN = N+ - N = 4 in
rotational angular momentum in a two-dimensional photoelectron spectra (2D-PES) of D2,
where the photoelectron yield is measured as functions of binding energy and incident
photon energy that was not recorded in a significant magnetic field [3]. The 2D-PES showed
features that correspond to the transitions, D2 X1Σg (v = 0, N = 0) → D2+ X 2Σg+(v + = 0, N+ = 0,
2, and 4). The autoionising state giving rise to the ΔN = 4 transition is observed at a photon
energy of 15.671-eV.
In this presentation we present measurements of the anisotropy parameter, β, for the
features that correspond to the transitions, D2 X1Σg (v = 0, N = 0) → D2+ X 2Σg+(v + = 0, N+ = 2
and 4). The measurements were made at the third-generation synchrotron source Elettra,
using an electron spectrometer that was developed for low kinetic energy electrons [4]. We
discuss the results of the β measurements and the factors that contribute to the large transfer
of angular momentum.
REFERENCES
1. G. Öhrwall and P. Baltzer, Phys. Rev. A. 58, 1960, (1998).
2. E. Sokell, M.K. Odling-Smee, A.A. Wills, D. Cubric, J. Comer and P. Hammond, J. Phys. B: At. Mol. Opt. Phys. 35, 1393, (2002).
3. A.M. Juarez, E. Sokell, P. Bolognesi, M.R.F. Siggel-King, G.C. King, M de Simone and M. Coreno, J. Phys. B: At. Mol. Opt. Phys. 39,
L377, (2006).
4. D. Cubric, A.M. Juarez, N.J. Bowring, F.H. Read and G.C. King, J. of Elec. Spect. and Relat. Phen. 123, 133, (2002).
SESSION V
Session chair: S. Svensson
IT-11
A tale of resonant Auger spectroscopy seen (mostly) from the point of view
of the N2 molecule
A. Kivimäki
IT-12
High-resolution Auger spectroscopy: A powerful tool to study metastable
molecular dications
R. Püttner
IT-13
P. Morin
IT-11
A Tale of Resonant Auger Spectroscopy Seen
(Mostly) from the Point of View of the N2 Molecule
A. Kivimäki
CNR-IOM, TASC Laboratory, 34149 Trieste, Italy
ABSTRACT
Resonant Auger (RA) spectroscopy is a versatile technique to study the electronic
structure and dynamics of atoms, molecules, clusters, etc. The first RA study on molecular
species was performed in 1983 at the N 1s → π* resonance of the N2 molecule with
synchrotron radiation excitation [1]. Shortly after, T. D. Thomas and co-workers used
electron-electron coincidence spectroscopy to record the RA spectra of N2 and CO with
electron excitation [2,3]. RA spectra can be interpreted in terms of participator and spectator
transitions, which lead to one-hole (1h) and two-hole one-electron (2h-1e) final states,
respectively. In 1987, Thomas’ group reported the first observation of lifetime vibrational
interference (LVI) in the NO molecule [4]: participator decay from different, coherently excited
vibrational levels of a core-excited state can modify the vibrational envelope of a 1h final
state. The LVI analysis has been able to explain successfully vibrationally resolved
participator spectra, e.g. at the N 1s → π* excitation of N2 [5], but it completely neglects the
direct photoionization channel. Tanaka et al. [6] have later presented how the LVI treatment
can be extended to situations, where both direct and resonant ionization channels as well as
interference between them need to be taken into account.
In the present work, interference between direct photionization and participator Auger
decay has been observed at the N 1s → Rydberg excitations of the N2 molecule. The
valence photoelectron spectrum of N2 was measured at the N 1s → 3sσ and 3pπ Rydberg
excitations and its vibrational structure was simulated numerically using the model of Ref. [6].
The relative partial ionization cross sections to the X, A and B states of the N2+ ion were
obtained in the region of the N 1s → Rydberg excitations. Those of the X and A states
appear to resonate at all Rydberg excitations, showing Fano line shapes, while the intensity
of the B state is essentially affected only by the first Rydberg excitation, N 1s → 3sσ. The
simulated photoionization cross section of the A state reproduces the experimental results
fairly well, but it fails in some details. The effects of participator decay from core-to-Rydberg
excited states also manifest themselves in the partial ion yield of the N2+ ion measured in the
N 1s threshold region.
REFERENCES
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2.
3.
4.
5.
6.
W. Eberhardt et al., Phys. Rev. Lett. 51, 2370-2373 (1983).
H. W. Haak, G. A. Sawatzky, L. Ungier, J. K. Gimzewski and T. D. Thomas, Rev. Sci. Instrum 55, 696-2504 (1984).
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R. Feifel et al., Chem. Phys. Lett. 383 (2004) 222.
T. Tanaka et al., Phys. Rev. A 72, 022507 (2005).
IT-12
High-resolution Auger Spectroscopy: A Powerful
Tool to Study Metastable Molecular Dications
Ralph Püttner
Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany
ABSTRACT
Molecular dications, M++, are normally dissociative. However, in special cases like in
molecules with a multiple bond structure these dications can also be metastable. In these
cases high-resolution Auger spectra recorded subsequent to photoionization of a shallow
core hole level exhibit vibrational structures. These structures can be subject to a FranckCondon analysis based on the assumption of Morse potential for all states involved. By
including in this fit analysis sophisticated effects like lifetime interference or post collision
interaction, detailed information about the potential energy curves of the metastable
dicationic states can be obtained [1,2].
After presenting the key contributions of the data analysis, the C 1s and the O 1s Auger
spectra measured at 400 eV and 550 eV, respectively, are presented and the derived
potential energy curves are compared with theoretical results revealing an excellent
agreement [3].
These results on CO are utilized to analyze O 1s Auger spectra measured recently using
photon energies of 550 eV [4]; this energy corresponds to the maximum of the shape
resonance directly above threshold. The spectra obtained at 550 eV show distinct differences
to the spectra measured well above threshold. In particular, in the energy region of the O 1s-1
→ b1Π and O 1s-1 → a1Σ+ Auger transitions which are well-known to consist of vibrational
progressions [3], additional narrow lines are found in the recent spectra. In a fit analysis
using results of Ref. [3] in combination with a detailed study of the lineshapes and angular
distribution, these additional lines were identified as resonant Auger decays of doubly excited
states to highly excited states of CO+. A tentative assignment of the different states is
obtained and the final states of CO+ turned out to be in an energy region which has not been
studied before.
Finally, further examples like O2 [5] or NO [6] will be given and the results shall be
compared with those from literature. The dication NO++ is one of the very rare cases with
experimentally observed rotationally resolved spectra of optical transitions [7]. This allows
demonstrating the high accuracy of the present method based on a Franck-Condon analysis
by comparing the equilibrium distances for the various states obtained with the two methods.
REFERENCES
1. R. Püttner, Y. F. Hu, G. M. Bancroft, H. Aksela, E. Nõmmiste, J. Karvonen, A. Kivimäki, and S. Aksela, Phys. Rev. A 59, 4438.
2. R. Püttner, V. Pennanen, T. Matila, A. Kivimäki, M. Jurvansuu, H. Aksela, and S. Aksela, Phys. Rev. A 65, 042505.
3. R. Püttner, X.-J. Liu, H. Fukuzawa, T. Tanaka, M. Hoshino, H. Tanaka, J. Harries, Y. Tamenori, V. Carravetta, and K. Ueda, Chem.
Phys. Lett. 445, 6 (2007).
4. R. Püttner, D. Céolin, O. Travnikova, J. Palaudoux, M. Hoshino, H. Kato, H. Tanaka, Y. Tamenori, C. C. Wang, C. Miron, K. Ueda,
and M.N. Piancastelli, in preparation.
5. T. Arion, R. Püttner, C. Lupulescu, R. Ovsyannikov, M. Förstel, G. Öhrwall, A. Lindblad, K. Ueda, S. Svensson, A.M. Bradshaw, W.
Eberhardt, and U. Hergenhahn, J. Electron Spectrosc. Relat. Phenom. in print.
6. R. Püttner, V. Sekushin, H. Fukuzawa, T. Uhlíková, V. Špirko, T. Asahina, N. Kuze, H. Kato, M. Hoshino, H. Tanaka, T. D.
Thomas, E. Kukk, Y. Tamenori, G. Kaindl, and K. Ueda, Phys. Chem. Chem. Phys. 13, 18436 (2011).
7. D. Cossart, M. Bonneau and J. M. Robbe, J. Mol. Spectrosc. 125, 413 (1987); D. Cossart and C. Cossart-Magos, J. Mol. Spectrosc.
147, 471 (1991).
IT-13
Ultrafast Dissociation: An Unexpected Tool
for Probing Molecular Dynamics
P. Morin* and C. Miron†
Synchrotron SOLEIL, l’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
ABSTRACT
Ultrafast dissociation following core-shell excitation into an antibonding orbital led to the early
observation in HBr of atomic Auger lines associated to the decay of dissociated excited
atoms. The purpose of this contribution is to review the very large variety of systems where
such a situation has been encountered, extending from simple diatomic molecules to more
complex systems such as polyatomic and adsorbed molecules or clusters. Interestingly, this
phenomenon has revealed an extremely rich and powerful tool for probing nuclear dynamics
and its subtle interplay with electron relaxation occurring on a comparable time scale.
Consequently we cover a surprisingly large period, starting in 1986 [1] and still ongoing [2],
covering the description of the initial findings, the quantum and angular aspects, the
extension towards complex species and pointing out the competition between dissociation
and Auger relaxation.
We will revisit the relaxation phenomena occurring in molecular core-excited states form the
viewpoint of the competition, on the ultra short (fs) time scale set by the core-hole lifetimes of
light elements, between electronic (mainly Auger) decay and nuclear motion. Although the
main topic deals with the extreme cases where the nuclear/dissociation dynamics is fast
enough so that the electronic decay occurs essentially in an isolated fragment after the twobody separation occurs in the core-excited state, a more general and frequent situation is
found when the dissociation is not complete in the intermediate state, or when the vibrational
motion in the core-excited state strongly influences the electronic decay as well as the ionic
fragmentation, which can be probed by coincidence experiments. It is clear that the initial
wave packet dynamics at an early stage influences strongly the subsequent evolution of the
systems, and explains why the “ultrafast dissociation” term is so extensively used nowadays
for many more complex situations, including polyatomic molecules where multimode nuclear
motion may occur, clusters or molecules adsorbed on surfaces.
Recent investigations under analysis suggest that UFD is a much more complex
process than its simplified description as a two-body neutral dissociation, and that it gives
access to a deeper understanding of other fundamental phenomena such as the important
questions of hole/charge localization in inversion symmetric species, symmetry breaking,
recoil phenomena, or multimode dissociation of large polyatomic species, with possible
important implications in radiation damage of living matter.
REFERENCES
[1] P. Morin and I. Nenner, Phys. Lett. 56 (1986) 1913
[2] M. Gerones, M.F. Erben, R. M. Romano,R.L. Cavasso Filho and C. O. Della Vedova, J.Phys.Chem. A 116 (2012) 2571
*
†
[email protected] [email protected] SESSION VI
Session chair: K. Prince
IT-14
High energy structures in molecular photoionization
P. Decleva
IT-15
High-resolution electron spectroscopy: Cross sections and asymmetry
parameters in complex species
M. Patanen
OC-08
Accurate carbon 1s hole-state lifetimes for chlorinated methanes
M. Zahl
IT-14
High Energy Structures
in Molecular Photoionization
Piero Decleva
Universita’ di Trieste Dipartimento di Scienze Chimiche e Farmaceutiche, Via Giorgeri 1, Trieste, Italy
ABSTRACT
A theoretical study of high energy structures in molecular photoionization will be presented,
bridging the gap between interference oscillations (Cohen-Fano) in photoemission from 1s
orbitals in diatomics to HOMO/HOMO-1 oscillations in C60. Universality of the features will
be stressed, which appear both in the valence and core ionization, in the generality of
molecular systems, and in all observables, cross sections, angular distributions, non-dipole
parameters, vibrational branching ratios, MFPADS. The interplay between geometrical
effects and electronic structure, i.e. chemical effects, will be analyzed. Analogies and
differences with EXAFS oscillations in photoabsorption will be considered, as well as
differences between interference and diffraction effects. Connection with recent experimental
results will be discussed
IT-15
High-resolution Electron Spectroscopy:
Cross Sections and Asymmetry Parameters
in Complex Species
M. Patanen
Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
ABSTRACT
High-resolution angularly resolved photoelectron spectroscopy can give an insight not only
into electronic structure, but also into geometrical orientation of the nuclei in the studied
molecule. Recently, chloroethanes were demonstrated to exhibit a nonstoichiometric ratio
between the cross-sections of the chlorinated and methyl group carbons for a wide range of
photon energies1. The ratio show x-ray-absorption fine structure spectroscopy (EXAFS)-like
oscillations, and even hundreds of eV above the C1s edge ratio is not 1. Moreover, the C1s
photoelectron asymmetry parameters (ß) of chlorinated and methyl group carbons show
clearly different ß values at low photon energies, the difference being larger the more
hydrogens are substitued with chlorine atoms in the series.
Oscillations were also observed in the differential photoionization cross section ratios
=1/ =0 of the symmetric stretching mode of C 1s photoionization in CF4. Far from
threshold, the oscillations are due to the diffraction of the photoelectrons by the neighboring
atoms and they allow recovery of the molecular geometry for a gas-phase polyatomic
molecule2. We now observed extra features in the cross-section ratios, which might be
interpreted by the presence of continuum resonances, in particular close to threshold.
A third example will be given on strong angular effects in inner-valence
photoionization hydrogen chloride molecule, where vibrationally resolved spectra show
almost completely vanishing transitions when using linearly polarized light perpendicular to
electron detection axis compared to parallel polarization.
All the experiments were carried out at PLEIADES beamline3 at SOLEIL synchrotron
in Saint-Aubin, France. The results are interpreted using state-of-the-art theoretical tools by
different theoretical groups. The good agreement between experiments and theory indicates
the larger scale feasibility of structural information extraction from single-molecule electron
diffraction experiments using synchrotron radiation and standard photoelectron
spectroscopy.
Acknowledgements: J. Söderström, O. Travnikova, X.-J. Liu, C. Nicolas, K. J. Børve, L. J.
Sæthre, N. Mårtensson, T. D. Thomas, J. J. Rehr, J. J., Kas, F. D., Vila, S. Svensson, K.
Kooser, E. Plésiat, D. Ayuso, M. Kimura, S. Mondal, L. Argenti, A. Palacios, K. Sakai, P.
Decleva, E. Kukk, K. Ueda, F. Martín, R. Linguerri, M. Hochlaf, J. H. D Bozek, and C. Miron
are acknowledged for their contribution in either data collection, scientific discussions or
theoretical modeling of the results.
REFERENCES
1. J. Söderström et al., Phys. Rev. Lett. 108, 193005 (2012)
2. E. Plésiat, L. Argenti, E. Kukk, C. Miron, K. Ueda, P. Decleva, and F. Martín, Phys. Rev. A 85, 023409 (2012)
3. http://www.synchrotron-soleil.fr/Recherche/LignesLumiere/PLEIADES
OC-08
Accurate Carbon 1s Hole-state
Lifetimes for Chlorinated Methanes
M.G. Zahl, K.J. Børve and L.J. Sæthre
University of Bergen, Dep. of Chemistry, Allègaten 41, NO-5007 Bergen, Norway
ABSTRACT
Upon core ionization, the residual ion is in a highly excited state with a finite lifetime. For
lighter elements, the main route of decay is the Auger process. The finite lifetime of the
excited state induces an uncertainty in the energy of the state, observed as a Lorentzianshaped broadening of the core-ionization spectrum. The possibility of chemical effects on
lifetime broadening has been a topic of experimental and theoretical research for decades.
However, molecular vibrations and instrumental resolution will also add complexity to and
induce broadening to a photoelectron spectrum, and lifetimes can therefore be difficult to
extract from measurements. Due to this, accurate experimental lifetimes are scarce in the
literature.
This presentation will focus on the experimental determination of carbon 1s lifetime widths for
the series of chlorinated methanes [CH4-nCln, n = 1, ... , 4]. The carbon 1s photoelectron
spectra have been carefully analyzed, both with respect to vibrational fine structure and
instrumental broadening. The most important tool has been extensive calculations to arrive at
accurate theoretical vibrational lineshapes. The resulting lifetime widths correspond very well
with theoretical predictions using the one-center model for molecular Auger transitions
proposed by Larkins and co workers1. The measurements provide clear evidence that the
one-center model is largely correct for the present set of molecules, and furthermore,
suggests that when this is the case, carbon 1s lifetime widths correlate well with the electron
density on the carbon atom.
REFERENCES
1. T. R. Walsh, T. E. Meehan and F. P. Larkins, J. Phys. B 27 (1994) 2211-2216.
POSTERS
Posters
PO-01
Electron and Photon Impact on Condensed Alcohols: Relevance to Solid
State Astrochemistry
G.C. Almeida
PO-02
K-shell Photoionization of Atomic Nitrogen Isonuclear Sequence (N2+, N3+,
N4+): Experiment and Theory
M.M. Al Shorman
PO-03
Coherence and Loss of Coherence in the Photoionization of Inversion
Symmetric Systems
U. Becker
PO-04
Fluorescence Decay Processes following Resonant 2p Photoexcitation of
Ar Atoms and Clusters using a Time-resolved Fluorescence and Photoion
Coincidence Technique
T. Gejo
PO-05
Two-slit Interference in Molecular Photoionization
R.K. Kushawaha
PO-06
The Role of Rydberg States in VUV Photoionization of NO2 and (NO+, O-)
Ion Pair Formation
S. Marggi Poullain
PO-07
Photoionization of Heavy Ions
B.M. McLaughlin
PO-08
Electronic Band Structure of ZrSxSe2-x Layered Semiconductors
M. Moustafa
PO-09
PLEIADES – An Ultra High Resolution Soft X-ray Beamline for Advanced
Spectroscopic Studies of Diluted Species from Atoms to Nanoparticles
C. Nicolas
PO-10
Structural Determination of CF4 Obtained by Core-electron Spectroscopy
M. Patanen
PO-11
State-selective Dissociation of Ammonia Clusters Studied by Electron – Ion
– Coincidences
M. Patanen
PO-12
Spin-doublet and Vibration Resolution of Broad Shape Resonance Bands
in X-ray Absorption and Core-level Photoemission from Molecules
A. A. Pavlychev
PO-13
Intermediate State and Zero-point Molecular Motion Effects on Vibration
Resolved Photoelectron Spectra of Small Molecular Species
A. A. Pavlychev
PO-14
Gas Phase Studies of Biomolecules: Antibiotic Building Blocks and Some
Cyclopeptides
K.C. Prince
PO-15
Ultrafast Charge Transfer in Poly(thiophene) Probed by Resonant Auger
Spectroscopy
M.L.M. Rocco
PO-16
Resonant Inelastic Soft X-ray Scattering Spectra with Vibrational
Resolution
J.E. Rubensson
PO-17
Probing Interface Interaction of Molecular Adsorbates on Metal Substrates
with Resonant Photoelectron Spectroscopy
C. Sauer
PO-18
Many Body Effects in the Resonant Photoelectron Spectra of Metal-organic
Interfaces
A. Schöll
PO-19
Formic and Acetic Acid: Valence Threshold Photoelectron and
Photoionisation Total Ion Yield Studies and Discussion on their Relative
Acidity
M.R.F. Siggel-King
PO-20
S2p photoabsorption and ES-AEPICO Spectroscopy of DMDS, a Prototype
Molecule for the Study of the Disulfide Chemical Bonds
G. Simões
PO-21
Synchrotron Radiation Studies Of Hyperthermal Radicals And Plasma
Short-lived Species
S. Stranges
PO-22
Isolated Silicon Nanocrystals Probed by Synchrotron Radiation Soft X-rays
O. Sublemontier
PO-23
The ESCA Molecule Historical Remarks and New Results
S. Svensson
PO-24
Valence-shell Photoelectron Circular Dichroism (PECD) on Gas Phase
Alanine
M. Tia
PO-25
New Routes to Ultrafast Dissociation of Polyatomic Molecules
O. Travnikova
PO-01
Electron and Photon Impact on Condensed
Alcohols: Relevance to Solid State Astrochemistry
G.C. Almeida*, A.B. de Souza†, N. Lisboa*,
D. Andrade†, H.M. Boechat-Roberty‡ and M.L. Rocco*
* Instituto de Química, Universidade Federal do Rio de Janeiro, 21941-909, Rio de Janeiro, RJ, Brazil
† Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba,
12244-000, São José dos Campos, SP, Brazil
‡ Observatório do Valongo, Universidade Federal do Rio de Janeiro,
20080-090, Rio de Janeiro, RJ, Brazil
ABSTRACT
Methanol and ethanol are important precursors of more complex prebiotic species. Both
were found on icy mantles of interstellar grains in several astrophysical environments, such
as star formation regions, Sgr B21, RAFGL 70092 and astrophysical bodies such as the HaleBopp comet3. In all these astronomical environments, molecules in the gas phase and frozen
on dust grain surfaces are subjected to ionizing agents like UV and X-ray photons, charged
particles such as protons, alpha particles and electrons, leading to ionization, dissociation
and desorption processes. Some mechanisms were proposed for the formation of interstellar
methanol and ethanol in the gas phase. However, as pointed by Millar and co-workers4,
chemical reactions occurring in the gas phase are not enough to explain the relatively high
abundances of these alcohols, therefore reaction pathways on grain surfaces are required.
The interaction of stellar radiation and charged particles with icy alcohols on grain
surfaces produces neutral or ionic fragments such as H2CO, CH3O, HCO, CH3, CO and H, C
and O free atoms. At surface temperatures around 50 K these radicals can readily diffuse to
form more complex molecules like acetic acid (CH3COOH) and methyl formate (HCOOCH3)5.
Those chemicals enrich the astrophysical ice composition and can sublimate from the ice
surface to the gas phase. To understand the chemical evolution and to quantify the role of
methanol, ethanol and more complex organic molecules in the gas phase and in the icy
mantles of interstellar grains, it is necessary to establish the main formation routes, which
require the study of the ionization, dissociation and desorption of these molecules caused by
interaction with ionizing agents.
In the present work we employed soft X-ray photons at the oxygen 1s-edge and variable
energy electrons to simulate the effects of stellar radiation field on the astrophysics ices.
These results were also compared with effects produced by charged particles from the solar
wind. They show that fragments released due to 850-1400 eV electrons are mainly caused
by C-O bond rupture, since CHn and C2Hn (1<n<4) fragments have the highest yields at
these energies. Fragments like CH3O+ and CH3CH2O+ were observed for energies higher
than 1400 eV, suggesting that electrons with energy near the O 1s ESID threshold can
promote O-H bond breakage more easily. Fragments released due to 537 eV photons tends
to provide fragments due to C-O and O-H bonds rupture, since CH2+, CO+, HCO+ and H+
were the most intense fragments.
Acknowledgments: CNPq, FAPERJ, LNLS.
REFERENCES
1. P. Schilke, T.D. Groesbeck, G.A. Blake and T.G. Phillips, Astrophys. J. Suppl. Ser. 108, 301-337 (1997)
2. E. Dartois, W. Schutte, T.R. Geballe, K. Demyk, P.Ehrenfreund and L. d'Hendecourt A&A,342, L32 (1999)
3. J. Crovisier, Faraday Discuss.109, 437-452 (1998)
4. T.J. Millar., E. Herbst, and S.B. Charnley, ApJ, 369, 147-156 (1991)
5. D.P.P Andrade, M.L.M. Rocco, H.M. Boechat-Roberty, Mon. Not. R. Astron. Soc. 409, 1289–1296 (2010)
PO-02
K-shell Photoionization of Atomic Nitrogen
Isonuclear Sequence (N2+, N3+, N4+):
Experiment and Theory
M.M. Al Shorman2,3,M.F. Gharaibeh1, J.M. Bizau2,3, D. Cubaynes2,3,
S. Guilbaud2, N. El Hassan2, C. Miron3, C. Nicolas3, E. Robert3,
C. Blancard4,7 and B.M. McLaughlin5,6.
1 Department of Physics, Jordan University of Science and Technology, Irbid 22110, Jordan.
2 Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS UMR 8214, Université Paris-Sud,
Bât. 350,F-91405 Orsay cedex, France.
3 Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48 91192 Gif-sur-Yvette cedex, France
4 CEA, DAM, DIF, F-91297 Arpajon, France.
5 Centre for Theoretical Atomic, Molecular and Optical Physics (CTAMOP), School of Mathematics
and Physics, Queen’s University Belfast, Belfast BT7 1NN, UK.
6 Institute for Theoretical Atomic and Molecular Physics (ITAMP), Harvard Smithsonian Center for
Astrophysics, MS-14, Cambridge, MA 02138, USA.
7 Observatoire de Paris, LUTH, CNRS UMR 8102, 5 place Jules Janssen, F-92195 Meudon, France.
ABSTRACT
Recently, extensive photoionization cross-section calculations, using sophisticated codes
such as R-matrix and MCDF (Multi-Configurational Dirac–Fock), have been performed along
isolectronic sequences to interpret the wealth of x-ray spectra currently provided by Chandra
and XMM-Newton observatories [1,2].These cross sections are widely used for modeling of
many astrophysical objects, but also laboratory plasmas involved in industrial applications.
Photoabsorption from low-lying metastable states of open-shell nitrogen-like ions has been
shown to play an important role in the chemistry of the earth’s upper atmosphere [3,4].
Until recently, little experimental data were available to benchmark these calculations. Such
data are now available from ion-photon merged beams experiments at undulator beamlines
in synchrotron radiation facilities. This technique allows absolute photoionization cross
section measurements on multiply charged ions and, therefore, opens the way to systematic
studies along isoelectronic sequences. Moreover, the use of hot plasma source like the ECR
permits photoionization studies of long-lived metastable ionic states [4].
We will present results on the K-shell photoionization processes for ions of the nitrogen
isoelectronic sequence (N2+, N3+, N4+) in the ground and metastable states. The
measurements have been obtained with the MAIA set-up permanently attached to the branch
A of the PLEIADES beam line at SOLEIL. They will be compared with the results of MCDF
and R-Matrix calculations.
REFERENCES
1.
2.
3.
4.
M F Gharaibeh et.al, J. Phys. B: At. Mol. Opt. Phys. 44 (2011) 175208.
J. García et.al, The Astrophysical Journal Supplement Series, 185:477–485, 2009 December.
M. M. Sant'Anna et.al, Phys. Rev. Lett. 107, 033001 (2011) [4 pages].
A Aguilar et.al, J. Phys. B: At. Mol. Opt. Phys. 38 (2005) 343–361.
PO-03
Coherence and Loss of Coherence in the
Photoionization of Inversion Symmetric Systems
Uwe Becker
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany and
King Saud University Riyadh, Saudi Arabia
ABSTRACT
The electronic states of inversion symmetric systems such as homonuclear diatomic molecules
are eigenstates of the Parity operator, the so-called delocalized gerade and ungerade eigenstates.
These states are coherent superpositions of both atomic sites of the molecule giving rise to double
slit like oscillations in the photoabsorption cross section of these molecules. These are the wellknown Cohen-Fano oscillations [1,2]. A less well-known fact is the characteristic behavior of these
oscillations depending whether the electrons are emitted from a randomly distributed or an
oriented target. This should give rise to a phase shift of π/2 between both situations regarding their
corresponding Cohen-Fano oscillations. We show this phase shift effect unambiguously for the first
time for the photoionization of molecular hydrogen. [3]
More astonishingly is, however, the unexpected phenomenon, that even for the randomly
oriented target the oscillatory behavior converts into the one of an oriented target for high
photoelectron kinetic energies. This transition between the two behaviors is brought about by the
recoil momentum of the photoelectron, which reveals the molecular axis orientation at the moment
of its emission. This unexpected transition phenomenon from randomness to order has been
observed for the first time for the case of molecular hydrogen.
Coherent oscillations appear in both the cross section and the angular distribution asymmetry
parameter. There is the assumption that these oscillations are closely related to each other, in fact
the β-oscillation should be the inverse of the σ-oscillation on the basis of Cooper and Zare’s
formulation [4] of the photoionization process in form of partial photoelectron waves. We could
prove this intriguing relationship for the N2 valence ionization over a wide photon energy range for
the first time. Experiments on further molecules are required to prove the generality of this
statement.[5]
Decoherence occurs if the gerade and ungerade Parity eigenstates are coherently
superimposed. This can be either in the decay or excitation process. We have chosen the
excitation of the core electron of O2 to energetically degenerate gerade and ungerade states,
which are hence coherently superimposed. This coherent superposition shows up by the Fano
profile of the corresponding partial cross section. The coherent superposition of the gerade and
ungerade Parity states causes decoherence of the position states and hence localization of the
electron emitter site. By choosing two very different decay time scales for the so-called first [6] and
second step Auger [7] emission we were able to demonstrate the electron tunneling effect by
Doppler shifted electron-fragment ion coincidence experiments as introduced by Kugeler et al. [8]
as a tool for studying the behavior of dissociating molecular systems. This complex but
enlightening relationship will be explained in more detail in the talk. [9]
REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
H. D. Cohen and U. Fano, Physical Review 150 (1966) 30
O. A. Fojon et al., Journal of Physics B 37 (2004) 3035
G. Hartmann et al. Book of Abstracts of the ICESS 2012, Saint Malo, France
J. Cooper and R. Zare, Journal of Chemical Physics 48, (1968)
M. Illchen et al. Book of Abstracts of the ICESS 2012, Saint Malo, France
O. Björneholm et al., Physical Review Letters 84, 2826 (2000)
R. Guillemin, M. Simon, and E. Shigemasa, Physical Review A 82, 051401 (2010)
O. Kugeler et al. Physical Review Letters 93 (2004) 33002
B. Langer et al. Book of Abstracts of the ICESS 2012, Saint Malo, France
PO-04
Fluorescence Decay Processes following Resonant
2p Photoexcitation of Ar Atoms and Clusters using
a Time-resolved Fluorescence and Photoion
Coincidence Technique
T. Gejo, T. Ikegami, K. Honma, J. R. Harries1 and Y. Tamenori2
Univ. of Hyogo, Kouto 3-2-1, Kamigori, Hyogo 678-1297, Japan
1
JAEA, Kouto 1-1-1, Sayo, Hyogo 678-5198, Japan
2
JASRI, Kouto 1-1-1, Sayo, Hyogo 678-5198, Japan
ABSTRACT
The novel spectroscopic technique of (time-resolved fluorescence) – photo-ion coincidence
spectroscopy (TFPICO) has been applied to the investigation of the decay processes of 2p
inner-shell excited Ar atoms and clusters. For the Ar atom, only fluorescence accompanying
the production of Ar+ shows a strong excitation energy dependence. For Ar clusters, similar
fluorescence lifetimes were observed in coincidence with the generation of Ar+. The TFPICO
spectra for dimer ions (Ar2)+ suggest that the long-lifetime fluorescence observed for Ar
clusters can be attributed to the “third excimer continuum” of Ar dimer cations. With this work
we demonstrate the usefulness of this technique for investigating the decay processes of
inner-shell excited atoms and clusters.
PO-05
Two-slit Interference in Molecular Photoionization
R.K. Kushawaha1,2 , R. Guillemin1,2, L. Journel1,2, M. Patanen3,
C. Miron3, M. Simon1,2, M.N. Piancastelli1,2 and P. Decleva4,5,6
1
UPMC, Université Paris 06, LCPMR, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
2
CNRS, LCPMR (UMR7614), 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
3
Synchrotron SOLEIL, l' Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
4
Dipartimento di Scienze Chimiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy
5
Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali
Unità di Trieste, 34127 Trieste, Italy
6
CNR-IOM DEMOCRITOS, 34149 Trieste, Italy
ABSTRACT
We report evidence on two-slit interference phenomena [1-9] in photoionization of
polyatomic molecules, which we have observed in the photoelectron spectra measurement
for the series of molecules C2H2, C2H4 and C2H6 over the photon energy range of 70-700eV.
The experiments have been performed at SOLEIL on PLEIADES beamline [10].
Oscillations coming from two orbitals corresponding to in-phase and anti-phase
combinations of the same atomic orbitals are predicted exactly out of phase. Theoretical
calculations [11] show that similar oscillations are present also in valence molecular orbitals
(MOs). Here structures are less regular due to the more complex structure of the relevant
MO’s, which are generally delocalized over the entire molecule. A notable simple case if for
orbitals arising from atomic 2s orbitals. In this case the g/u splitting is much larger, several
eV’s and can be easily resolved and followed over a large photon energy range.
The experimental results show prominent oscillations in the 2σg/2σu intensity ratios with
photon energy and with a strong dependence on the C-C distance. The theoretical
calculations [11] have been done prior to the experiment for 1σg/1σu as well as 2σg/2σu. The
C2s derived orbitals are well defined and can be easily resolved experimentally over a large
excitation energy range, and thus the present experiment has been performed to understand
the effect of molecular orbital localization/delocalization on photoionization. The observed
oscillations are not symmetric, which reflects the different degree of admixture of the H1s
orbitals in the two 2σg/2σu C2s-derived MOs, and thus it is directly informative of the nature
of the inner-valence MOs.
REFERENCES
1.
2.
3.
4.
5.
6.
O. A. Fojón, J. Fernández, A. Palacios, R. D. Rivarola and F. Martín, J. Phys. B: At. Mol. Opt. Phys. 37, 3035 (2004).
O. A. Fojón, A. Palacios, J. Fernández, R.D. Rivarola, F. Martín, Physics Letters A 350, 371–374(2006).
M. Arndt, Nature Physics 1, 19 (2005).
X-J. Liu et al., J. Phys. B: At. Mol. Opt. Phys. 39, 4801 (2006).
S. K. Semenov, et al., J. Phys. B: At. Mol. Opt. Phys. 39, L261(2006)
X.-J. Liu, G. Prümper, F. Gel’mukhanov, N.A. Cherepkov, H. Tanaka, K.Ueda, J. Electron Spectrosc. Related Phenom. 156–158,
73–77, (2007).
7. D Rolles et al., Nature, 437, 711(2005).
8. B. Zimmermann et al., Nature Physics 1, 1 (2008).
9. H. D. Cohen and U. Fano, Phys. Rev., 150, 30(1966).
11. P. Decleva, unpublished results
PO-06
The Role of Rydberg States in VUV Photoionization
of NO2 and (NO+, O-) Ion Pair Formation
S. Marggi Poullain1, R. R. Lucchese2, J. C. Houver1, P. Billaud1,
M. Lebech3, Y. J. Picard1, K. Veyrinas1 and D. Dowek1
1
Institut des Sciences Moléculaires d'Orsay, Bat. 350, UMR 8214, Université Paris Sud et CNRS,
91405, Orsay Cedex, France,
2
Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
3
Niels Bohr Institute, University of Copenhagen
ABSTRACT
Photoion pair formation is governed by electronic and nuclear dynamics of neutral
molecules excited in the VUV range. Electronic states leading to ion pair formation are often
molecular super-excited states embedded in the ionization continua [1]. (NO+ + O−) ion pair
formation has been studied previously in one-photon [2] and multiphoton excitation [3] of the
NO2 molecule. Here we report a recent investigation of ion pair formation and NO2
photoionization induced by synchrotron radiation on the DESIRS beamline at SOLEIL using
the vector correlation (CV) method [4, 5].
The (NO+ + O−) as well as the NO2+ ion yield spectra recorded as a function of the
excitation energy between 11 and 13 eV, above the ion pair formation threshold at 10.918
eV, show well resolved peaks assigned to the excitation of vibrationally resolved [R*(4b2)-1]
Rydberg series converging to the NO2+ (a3B2) first excited state.
The CV method consists of the measurement in coincidence of the ejection velocity vector
of the positive and negative fragments from one photoionization or photodissociation
process. The (VNO+, VO-, P) and (VNO2+, Ve, P)) correlations lead to two detailed observables:
photoelectron energy spectrum and βe asymmetry parameter for photoionization channels
and kinetic energy release (KER) and βN asymmetry parameter of the ion fragments for
vibrationally resolved (NO+ (X1Σ+, v) + O– (2P)) ion pair channels, respectively.
Different relaxation mechanisms including autoionization processes of [R*(4b2)-1] Rydberg
series and the coupling between electronic and nuclear motions will be discussed by the
analysis of the different observables. The evolution of the βe asymmetry parameter with the
photoelectron energy is compared with calculations using the frozen-core Hartree-Fock
method performed for direct ionization.
REFERENCES
1.
2.
3.
4.
5.
M A. G. Suits and J.W. Hepburn, Ann. Rev. Phys. Chem., 2006 57, 431.
Berkowitz, J.; VUV and Soft X-ray Photoionization, ed. D.A. Shirley, p. 263, 1996 and ref. therein
Elkharrat et al., J. Phys. Chem. A, 2010, 114, 9902-9918.
Lebech, M.; Houver, J.C.; Dowek, D.; Rev. of Sci. Instrum., 2002, 73, 1866.
Toffoli, D.; Luchese, R.R.; Lebech, M.; Houver, J.C.; Dowek, D.; J. Chem. Phys., 2007, 126, 054307.)
PO-07
Photoionization of Heavy Ions
Brendan M McLaughlin
Centre for Theoretical Atomic Molecular and Optical Physics
School of Mathematics and Physics, The David Bates Building
Queens University of Belfast
Belfast BT7 1NN, UK
ABSTRACT
Photoionization, is an important process in determining the ionization balance and hence the
abundances of elements in photoionized astrophysical nebulae. It has recently become
possible to detect neutron n-capture elements (atomic number Z >30) in a large number of
ionized nebulae. These elements are produced by slow or rapid n-capture nucleosynthesis
(the s-process and r-process, respectively). Measuring the abundances of these elements
helps to reveal their dominant production sites in the Universe, as well as details of stellar
structure, mixing and nucleosynthesis. These astrophysical observations provide an impetus
to determine the photoionization and recombination properties of n-capture elements.
Planetary nebulae (PNe) progenitor stars may experience s-process nucleosynthesis, in
which case their nebulae will exhibit enhanced abundances of trans-iron elements. The level
of s-process enrichment for individual elements is strongly sensitive to the physical
conditions in the stellar interior. Accurate assessment of elemental abundances in
astrophysical nebulae can be made from the direct comparison of the observed spectra with
synthetic non-local thermodynamic equilibrium (NLTE) spectra, if the atomic data for electron
and photon interaction processes are known with sufficient accuracy.
Experiments on heavy trans-iron atomic ions at third generation synchrotron radiation
source, such the Advanced Light Source (ALS) in Berkeley, California have highlighted the
need for high quality theoretical work to fully interpret experimental results. A recently
developed theoretical code for parallel computing architectures (incorporating the necessary
relativistic effects within a Dirac-equation formulation) has been used to perform detailed
photoionization cross section calculations on a variety of atomic ion species, e.g.; Se, Kr, Ar,
Xe, in their low stages of ionization. Where possible we compare our results with ongoing
experiments being performed at the ALS. Such comparisons are necessary and serve as
the ultimate benchmark for our work in order to have confidence in the atomic data to be
incorporated into standard astrophysical modeling codes such as XSTAR and CLOUDY.
REFERENCES
1.
2.
3.
4.
5.
6.
B. M. McLaughlin and C. P. Ballance, J. Phys. B: At. Mol. Opt. Phys. 45 085701 (2012).
B. M. McLaughlin and C. P. Ballance, J. Phys. B: At. Mol. Opt. Phys. 45 095202 (2012).
A. Aguilar et al, J. Phys.Conf. Ser. in press (2012).
N. C. Sterling et al, Pub. Astron. Soc. Austr. 26 339 (2009).
A. Aguilar et al, J. Phys.Conf. Ser. 194 022088 (2009).
B. M. McLaughlin and C. P. Ballance, Photoionization, Fluorescence and Inner-shell Processes,
(McGraw Hill: New York and London) (2012).
PO-08
Electronic Band Structure of ZrSxSe2-x
Layered Semiconductors
M. Moustafa, C. Janowitz, and R. Manzke
Humboldt−Universität zu Berlin, Institut für Physik, Newtonstr. 15, D−12489 Berlin, Germany
ABSTRACT
The electronic structure of the layered transition metal dichalcogenide ZrSxSe2-x
semiconductors has been studied by means of high resolution angle−resolved
photoemission spectroscopy (ARPES) using synchrotron radiation. The chalcogen
p−derived valence bands of the complete series of ZrSxSe2-x are reported along the normal
direction and along the major symmetry directions of the hexagonal Brillouin zone parallel to
the layers. The results show that the binding energies of the topmost valence band shift
almost linearly with the composition parameterx. A characteristic splitting of the topmost
valence bands along high symmetry directions of the Se-rich compounds was observed.
Further, an emission from the conduction band minimum is observed just below the Fermi
edge. This emission verifies the indirect nature of the band gap and enabled us to
determine the band gap values directly by ARPES.
PO-09
PLEIADES – An Ultra High Resolution Soft X-ray
Beamline for Advanced Spectroscopic Studies
of Diluted Species from Atoms to Nanoparticles
C. Nicolas,1 X.J.Liu,1 E. Robert,1 M. Patanen,1 O. Travnikova,1
A. Lindblad,1 J. Söderström,1 B. Lagarde,1 F. Polack1, C. Miron1
1
Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin – BP 48,
91192 – Gif-sur-Yvette Cedex, France
ABSTRACT
PLEIADES is an ultra high-resolution soft X-ray beamline (7 eV to 1 keV) at SOLEIL in
France [1]. The beamline is dedicated to spectroscopic studies of dilute samples (atoms,
molecules, ions, biological molecules, free Van der Waals and metal clusters, isolated
nanoparticles). All types of light polarizations are available from an Apple II (80 mm period)
and an electromagnetic (256 mm period) undulator. The optics has been designed to reach
an ultimate resolving power of about 100000@50 eV thanks to a novel PGM design
employing varied line spacing VLS and varied grove depth VGD gratings [2].
A high-resolution electron spectrometer (VGScienta-R4000), an energy and angle
resolved Auger electron - ion coincidence setup (EPICEA), as well as a dedicated station
(MAIA) for positive and negative ion photoionization studies (ECR source) are permanently
installed on the beamline. A laser facility (c.w. and pulsed) can be used in addition to the
synchrotron beam, for pump-probe experiments.
Open to users since April 2010, PLEIADES beamline has allowed already to obtain
numerous results in relation with the decay dynamics of core-excited atoms and molecules,
atomic and molecular clusters or isolated nanoparticles, probed by electron-spectroscopy or
Auger electron – ion coincidence measurements. Examples illustrating the main
performances will be presented, as well as the latest experimental and optical updates.
REFERENCES
[1] http://www.synchrotron-soleil.fr/portal/page/portal/Recherche/LignesLumiere/PLEIADES
[2] F. Polack, B. Lagarde, C. Nicolas, E. Robert, C. Miron, et al., SRI09 conference, Melbourne, Australia.
PO-10
Structural Determination of CF4 Obtained
by Core-electron Spectroscopy
M. Patanen1, K. Kooser2, E. Plésiat3, D. Ayuso3, M. Kimura4, S. Mondal4,
L. Argenti3, A. Palacios3, K. Sakai4, O. Travnikova1, P. Decleva5,
E. Kukk2, C. Miron1, K. Ueda4, and F. Martín3,6
1
2
Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland
3
Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
4
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University,
Sendai 980-8577, Japan
5
Dipartimento di Scienze chimiche, Università di Trieste, IT-34127, and CNR-IOM, Trieste, Italy
6
Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco,
28049 Madrid, Spain
ABSTRACT
In this study the oscillatory structure of the differential photoionization cross section ratio
ν=1/ν=0 of the symmetric stretching mode of C 1s photoionization in CF4 is investigated. Far
from threshold, the observed oscillations are due to the diffraction of the photoelectrons by
the neighboring atoms and the observed oscillatory structure has been demonstrated to
allow recovery of the molecular geometry for a gas-phase polyatomic molecule1. Besides
seeing oscillations that can be explained by a simple analytical model based on Born
approximation, we now observed extra features, which might be interpreted by the presence
of continuum resonances, in particular close to threshold and which can be reproduced by ab
initio calculations at the DFT level of theory2,3.
The measurements took place at the PLEIADES beamline4 at SOLEIL synchrotron, France.
C 1s photoelectron spectra were measured using a VG-Scienta R4000 electron energy
analyzer at excitation energies ranging between 330 and 650 eV. The ν=1/ν=0 ratio of the
symmetric stretching mode was extracted from the spectra by a fitting procedure taking into
account the asymmetric vibrational modes excited by the recoil effect5.
The experimental results are in good agreement with theoretical predictions, thus indicating
the larger scale feasibility of structural information extraction from single-molecule electron
diffraction experiments using synchrotron radiation and standard photoelectron
spectroscopy.
REFERENCES
1.
2.
3.
4.
5.
E. Plésiat, L. Argenti, E. Kukk, C. Miron, K. Ueda, P. Decleva, and F. Martín, Phys. Rev. A 85, 023409 (2012)
S. E. Canton, E. Plésiat, J. D. Bozek, B. S. Rude, P. Decleva, and F. Martín, Proc. Natl. Acad. Sci. 108, 7302 (2011)
M. Venuti, M. Stener, and P. Decleva, Chem. Phys. 234, 95 (1998)
http://www.synchrotron-soleil.fr/Recherche/LignesLumiere/PLEIADES
T. D. Thomas et al., J. Chem. Phys. 128, 144311 (2008)
PO-11
State-selective Dissociation of Ammonia Clusters
Studied by Electron – Ion – Coincidences
M. Patanen, C. Nicolas, X.-J. Liu, O. Travnikova, C. Miron
ABSTRACT
Fragmentation of NH3 clusters is studied by energy selected electron – ion (ion) –
coincidence measurements, triggered either by photoelectron or resonant Auger electron
detection. Experiments were carried out at the PLEIADES beamline1 at SOLEIL synchrotron,
using EPICEA coincidence set-up2. Clusters were produced by adiabatic expansion of NH3
gas with 0.4 bar backing pressure through a 100 μm conical nozzle, which was cooled to ~
268 K. These conditions created large clusters (several hundred molecules in a cluster).
N 1s photoabsorption spectrum of NH3 clusters is very similar to molecular NH3 spectrum.
The first resonance (excitation to 4a1 orbital in NH3 molecule) appears to have the same
excitation energy as the molecular one, and second resonance (excitation to 2e orbital NH3
molecule) is slightly red-shifted.
N 1s photoelectron – photoion coincidence (PEPICO) measurement reveals that large
clusters dissociate producing predominantly (NH3)nNH4+, n = 0,1,2,… fragments, whereas
this fragmentation pattern can be modified significantly by exciting the N 1s electron to empty
valence orbital (4a1 or 2e in NH3 molecule). At these resonances the small fragments, N+,
NH+, and NH2+ are much more abundant compared to the excitation to a Rydberg state (6a1
in NH3 molecule), where the fragmentation pattern resembles the core-ionized one. An
especially interesting example is the excitation to the 4a1 orbital, which is known to exhibit
ultra-fast dissociation in NH3 molecules3.
REFERENCES
2. C. Miron et al., Rev. Sci. Instrum. 68, 3728 (1997) ; P. Morin et al., J. Electr. Spectr. Rel. Phen. 93, 49 (1998) ; D. Céolin. et al., J.
Electr. Spectr. Rel. Phen. 141, 171 (2004)
3. I. Hjelte et al., Chem. Phys. Lett. 370, 781–788 (2003)
PO-12
Sp
pin-doublet and
a Vib
bration
n Resollution o
of Broa
ad
Shape Re
esonan
nce Bands in X-ray Absorp
ption and
a
Core--level Photoe
P
emissio
on from
m Mole
ecules
Ye
e.I. Kan, X.O. Brykalova, Y
Yu.S. Kriv
vosenko and
a A. A.. Pavlychev
Stt. Petersburg
g State Unive
ersity, Uliano
ovskaia 1, Pe
eterhof, St. Petersburg,
P
1198504, Russ
sia
A
ABSTRACT
T
Specctral distrib
bution of oscillator strength (SDOS) for core-to-vvalence tra
ansitions
embedd
ded into the cotinuum
m is investi gated. The
ey are usua
ally assigneed with the
e shape
with the temporal trap
resonan
nces and associated
a
t
of the
e photoelecctron ejecte
ed from
molecullar core with
hin the finite
e size poten
ntial barrierr and with th
he subsequ ent tunnelin
ng of the
photoele
ectron thro
ough the barrier
b
into the core ionization continuum
m. The qua
antitative
encounterrs with gre
analysiss of the resonances
r
eat difficultties due too their substantial
asymme
etry, short photoelec
ctron trappiing (PET) time and interplay with multi--electron
nce transitions embed
excitatio
ons. SDOS
S for the core-to-valen
c
dded into tthe continu
uum are
examine
ed within th
he quasi-ato
omic (QA) a
approach [1]. It is state
ed that in th e shape res
sonance
vicinity SDOS is su
uccessfully reproduced
d by a triple
e convolution of asymm
metry and sy
ymmetry
Lorentz and Gausss distributio
ons LA*L*G
G. They tak
ke into acco
ount the P
PET time, core-hole
c
livetime
e and the ba
and width of the photon
n source. Special
S
emp
phasis is pu t on vibratio
onal and
multiele
ectron effectts in the SD
DOS. Within
n the VDFN model [2] the
t self connsistent app
proach to
the reso
onance proffile with fixe
ed vibration numbers is
s elaborated
d.
This approach is successfu
uly applied to model
and an
emission
nalyze the
e inner-shell photo-e
spectra above the S and Si L2,3 and C and N K
olecules.
edges iin the SF6, SiF4, CO and N2 mo
The asyymmetry Lo
orentz LA(k) distribution
n is found
dominatting in the
e line shap
pe of the core-tovalence
e transitions. The PET tim
mes are
determined. The spin-double
et as welll as the
n compon
nets of the
t
broad shape
vibration
resonan
nce bands are resolve
ed. Figure presents
the com
mparison of
o the model LA*L*G
G(k) and
experim
mental [3] sp
pectra as well
w as the e
extracted
spin-doublet and vibration components
c
s of the
broad S 2p3/2,1/2 Æ Eg shape
e resonance
e in SF6.
Prespecctives for further
f
quan
ntitative an
nalysis of
broad bands in
i
X-ray absorptio
on and
photoem
mission spe
ectra and fo
or separatio
on of the
shape and giant resonance
e phenom ena are Figure The experimeental [3] an
nd model line
discussed.
shape of th
he 2p3/2,1/2Æ
ÆEg resonan
nce in SF6
ENCES
REFERE
1.
A. A. Pavlychev, A.
A S. Vinogrado
ov, A. P. Stepannov, A. S. Shula
akov, Opt. Spec
ctrosc., 75, 554--573 (1993); E.O
O. Filatova and A.A.
Pa
avlychev, X-ray Optics
O
and Inner-s
shell electronics of Hexagonal BN
N. Nova Science
e Publishers, Inc.. NY. 2011.
2. A. A
A. Pavlychev, D. A. Mistrov, J. Ph
hys. B: At. Mol. O
Opt. Phys., 42 05
55103 (2009).
3. E. H
Hudson et al. Ph
hys. Rev. A, 47 361-373 (1993)
PO-13
Intermediate State and Zero-point Molecular Motion
Effects on Vibration Resolved Photoelectron Spectra
of Small Molecular Species
Yu.S. Krivosenko and A. A. Pavlychev
St. Petersburg State University, Ulianovskaia 1, Peterhof, St. Petersburg, 198504, Russia
ABSTRACT
Intermediate core-valence and valence excited states couple with zero-point molecular
motion resulting in specific changes in vibrational structure of the photoelectron lines. This
coupling is examined in the framework of the vibration-dependent-fixed-nuclei (VDFN) [1]
and the strong dynamic electron-hole localization approaches [2] to molecular
photoionization. Special emphasis is put on the photoelectron spectra of N2 and CO. Both
resonance behavior of the rotational energy of the B 2 Σ u+ state in N2+ and huge increase in
the population of high vibrational levels in the C 1s-1 ionized state in CO+ [3] are revealed.
+
The photoelectron-recoil-induced rotational excitation of the B 2 Σ u+ state in N 2 is found
resonantly enhanced in the regime of 400.8–402-eV photon energies. The rotational energy
δE as a function of photon energy are investigated to take the zero-point molecular motion
and the intermediate 1σu-11πg1 state into account. The calculations evidence a linear spectral
dependence of δE below and above the π*-resonance and the complicated resonance
+
behavior of the rotational excitation of the B 2 Σ u+ state in N 2 at 1σu(v=0) Æ 1πg (v’)
transitions. The computed increase in δE correlates with the photoelectron measurements
[4]. Interplay of the ro-vibrational interaction and the population of high vibrational levels in
*
the intermediate N 2 state is discussed.
The C and N 1s-1 photoelectron lines in
CO and N2 are found influenced by the
shake-up states that autoionize into the
core-1-ionization continuum. Striking nonFranck-Condon changes in the vibrational
structure and huge enhancement of the
vibrational v’>4 excitations is predicted.
Figure shows the predicted low intense
vibrational structure of the C 1s-1 photoline
in CO computed with the coupling. Zeroenergy coincides with the adiabatic (0-0)
transition.
Figure The fine vibration structure in CO.
REFERENCES
1.
2.
3.
4.
A. A. Pavlychev, D. A. Mistrov, J. Phys. B: At. Mol. Opt. Phys., 42 055103 (2009).
E.S. Klyushina, Yu.S. Krivosenko, A.A. Pavlychev, J. Math. Sci. 2012, submitted
Yu.S. Krivosenko, A.A. Pavlychev, Chem. Phys. Lett., 500 p.14-17 (2010)
T.D. Thomas et al., Phys. Rev. A, 79, 022506 (2009).
PO-14
Gas Phase Studies of Biomolecules:
Antibiotic Building Blocks and Some Cyclopeptides
K.C. Prince1,2, M. Ahmed3, A.P. Wickrama Arachchilage3, A. Ganesan3,
F. Wang3, V. Feyer1,4, O. Plekan1,5
1
Sincrotrone Trieste, in Area Science Park, I-34149 Basovizza, Trieste, Italy,
2
Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche,
Area Science Park, I-34149 Trieste, Italy,
3
eChemistry Laboratory, Faculty of Life and Social Sciences, Swinburne University of Technology,
Melbourne, Victoria 3122, Australia,
4
Present address: Forschungszentrum Jülich GmbH - IFF - IEE, 52425 Jülich, Germany,
5
Present address: Department of Physics and Astronomy, Ny Munkegade 120,
DK-8000 Aarhus C, Denmark.
ABSTRACT
A series of biomolecules have been investigated by valence and core level photoemission
supported by theoretical calculations. Some of these are molecular building blocks of beta
lactam antibiotics, namely 2-azetidinone and two isomers of thiazolidine carboxylic acid,
while the others are pharmacologically active cyclic dipeptides.
2-azetidinone has been the subject of a previous photoemission investigation [1] and here
we present updated spectra at higher resolution. The spectra of the two isomers of
thiazolidine-carboxylic acid are rather similar, as expected, but show clear effects due to
isomerization. Both isomers are analogs of proline, which is well known to populate several
low energy conformers in the gas phase [2]. We have investigated the low energy
conformers of thiazolidine-4-carboxylic acid theoretically in more detail and find some
spectroscopic evidence that multiple conformers may be present, by analogy with work on
conformers of ethanol [3].
Cyclic dipeptides are bio active compounds in which two amino acids for two peptide
bonds in a ring configuration, giving rise to a central diketopiperazine ring, with the
corresponding amino acid side chains attached to this ring. We have investigated six of these
compounds, starting from the simplest, cyclo(glycyl-glycyl), and five others based on proline,
phenylalanine, histidine, tyrosine and leucine [4, 5]. The valence spectra are generally
characterized by a restricted set of outer valence orbitals separated by a gap from most other
valence orbitals. The theoretically simulated core and valence spectra of all cyclic dipeptides
agree reasonably well with the experimental spectra. The central ring and the side chains act
as independent chromophores whose spectra do not influence one another, except for prolyl
dipeptides, where the pyrrole ring is fused with the central ring. In this case, significant
changes in the valence and core level spectra were observed, and explained by stronger
hybridization of the valence orbitals.
REFERENCES
1.
2.
3.
4.
5.
A. Greenberg, T. D. Thomas, C. R. Bevilacqua, M. Coville, D. Ji, J. C. Tsai, and G. Wu, J. Org. Chem. 57, 7093-7099 (1992).
O. Plekan, V. Feyer, R. Richter, M. Coreno, M. de Simone, K. C. Prince, and V. Carravetta, Chem. Phys. Lett.442, 429-433 (2007).
M. Abu-samha, K. J. Børve, L. J. Sæthre, and T. D. Thomas, Phys. Rev. Lett. 95, 103002 (2005).
A. P. Wickrama Arachchilage, F. Wang, V. Feyer, O. Plekan, and K. C. Prince, J. Chem. Phys. 133 (2010) 174319-174319.
A. P. Wickrama Arachchilage, F. Wang, V. Feyer, O. Plekan, and K. C. Prince, J. Chem. Phys. 136 (2012) 124301.
PO-15
Ultrafast Charge Transfer in Poly(thiophene)
Probed by Resonant Auger Spectroscopy
C. Arantes*,†, G. Araújo*, B. Beck*, L.S. Roman‡
and M.L.M. Rocco*
* Instituto de Química, Universidade Federal do Rio de Janeiro,
21941-909, Rio de Janeiro, RJ, Brazil
†
Divisão de Metrologia de Materiais (Dimat), Inmetro, Duque de Caxias,
RJ, CEP 25250-020, Brazil
‡
Departamento de Física, Universidade Federal do Paraná, 81531-990, Curitiba, PR, Brazil
ABSTRACT
Charge transfer dynamics is a topic of highly importance in fundamental and in
many applied areas like femtochemistry, surface photochemistry, molecular
electronics, solar energy, and so on [1,2]. Besides pump-probe optical experiments,
Auger decay spectra following core excitation emerges as an alternative with major
advantages. Firstly, because the core hole lifetime probed by core level spectroscopy
can be used as a fast internal clock and in so far very low timescales can be achieved,
the so-called core hole clock (CHC) method [2-6]. Secondly, because of the inherent
atomic specificity of core levels. For some applications, the surface sensitivity of low
energy electrons adds up.
Ultrafast electron transfer dynamics in the low-femtosecond regime was evaluated
for poly(thiophene) by resonant Auger spectroscopy (RAS) using the core-hole clock
method. Sulfur KL2,3L2,3 Auger decay spectra were measured as a function of the
photon energy. Remarkable changes developed by tuning the photon energy along the
sulphur 1s edge, depending on the core excited states. It was possible to disentangle
transitions to π*, σ* [ 6] and Rydberg states by RAS not resolved by XAS. Competing
Raman and Auger channels could be separated and charge transfer times derived.
Acknowledgments: CNPq, CAPES, LNLS.
REFERENCES
1. P. A. Brühwiler, O. Karis, and N. Mårtensson, Rev. Mod. Phys. 74, 703 (2002).
2. L. Wang, W. Chen, and A. T. S. Wee, Surf. Sci. Reports 63, 465 (2008).
3. D. Menzel, Chem. Soc. Rev. 37, 2212 (2008).
4. W. Wurth and D. Menzel, Chem. Phys. 251, 141 (2000).
5. A. Föhlisch, Appl. Phys. A 85, 351 (2006).
6. H. Ikeura-Sekiguchi and T. Sekiguchi, Surf. Interface Anal. 40, 673 (2008).
PO-16
Resonant Inelastic Soft X-ray Scattering Spectra
with Vibrational Resolution
J.-E. Rubensson1, F. Hennies1,2, A. Pietzsch2, Y.-P. Sun3,4, B. Kennedy2,
T. Schmitt5, V. N. Strocov5, J. Andersson1, J. Schlappa6, A. Föhlisch6,7,
and F. Gel'mukhanov3
1
DEPARTMENT OF PHYSICS AND ASTRONOMY, BOX 516, UPPSALA UNIVERSITY,
SE-751 20 UPPSALA, SWEDEN
2
MAX-LAB, LUND UNIVERSITY, BOX 118, S-221 00 LUND, SWEDEN
3
DEPARTMENT OF THEORETICAL CHEMISTRY AND BIOLOGY, SCHOOL OF BIOTECHNOLOGY,
ROYAL INSTITUTE OF TECHNOLOGY, S-106 91 STOCKHOLM, SWEDEN
4
SCHOOL OF SCIENCE, SHANDONG UNIVERSITY OF TECHNOLOGY, ZIBO,
255049, SHANDONG, PEOPLESREPUBLIC OF CHINA
5
SWISS LIGHT SOURCE, PAUL SCHERRER INSTITUT, CH-5232 VILLIGEN, SWITZERLAND
6
INSTITUTE FOR METHODS AND INSTRUMENTATION IN SYNCHROTRON RADIATION
RESEARCH G-I2, HELMHOLTZ-ZENTRUM BERLIN FÜR MATERIALIEN UND ENERGIE,
ALBERT-EINSTEIN-STR. 15 D-12489 BERLIN, GERMANY
7
FAKULTÄT FÜR PHYSIK UND ASTRONOMIE, UNIVERSITÄT POTSDAM, KARL-LIEBKNECHTSTRASSE, 24-25 D-14476 POTSDAM, GERMANY
ABSTRACT
Resonant inelastic X-ray scattering (RIXS) reflects fine details in electronic structure and
dynamics. The process is site specifc on the atomic length scale (sub-nanometer) and time
specifc on the timescale for nuclear and electronic rearrangements (femto- to attoseconds).
Consequently, RIXS spectroscopy has a tremendous potential in atomic and molecular,
chemical and condensed matter physics. RIXS techniques have, however, suffered from the
lack of adequate radiation sources. In practice this has limited the spectral quality and only a
fraction of the inherent advantages have been exploited.
Here RIXS spectra of the free oxygen molecules and liquid acetone with an energy
resolution (E/ΔE≈10000) that allows for separation of individual vibrational excitations [1] are
presented. This opens a wealth of new possibilities, provides detailed information about
ultrafast dynamics, and facilitates accurate mapping of the final state potential surfaces. We
observe spatial quantum beats in the dissociating oxygen molecule [2], establish a new
selection rule due to internal spin coupling, and demonstrate hole-electron parity swap during
the scattering process [3].
The measurements were made with the SAXES spectrometer [4] at the ADRESS
beamline [5] at the Swiss Light Source of the Paul Scherrer Institut, using a gas/liquid cell
with an ultrathin membrane. The data is discussed in terms of ab-initio multimode scattering
calculations.
REFERENCES
[1] F. Hennies, et al., Phys. Rev. Lett. 104, 193002 (2010).
[2] A. Pietzsch, et al., Phys. Rev. Lett., 106, 153004 (2011).
[3] Y.- P. Sun, et al, J. Phys. B 44, 161002 (2011).
[4] G. Ghiringhelli et al., Rev. Sci. Instrum. 77, 113108 (2006).
[5] V. N. Strocov et al., J. Synchrotron Radiat. 17, 631 (2010).
PO-17
Probing Interface Interaction of Molecular
Adsorbates on Metal Substrates with Resonant
Photoelectron Spectroscopy
C. Sauer, M. Häming, M. Wiessner, S. Gusenleitner,
F. Bruckner, A. Schöll and F. Reinert
Universität Würzburg, Experimentelle Physik VI, Am Hubland, D-97074 Würzburg, Germany
Gemeinschaftslabor für Nanoanalytik, Karlsruher Institut für Technologie KIT,
D-76021 Karlsruhe, Germany
ABSTRACT
Resonant photoelectron spectroscopy (ResPES) allows probing the electronic structure of
surfaces and interfaces in conjunction with local information enabled by the site-selective Xray absorption [1]. Furthermore it provides access to the time domain on the fs- and even asscale with the core-hole clock technique [2] and thus a quantitative investigation of charge
transfer (CT) at interfaces is possible. Moreover, the resonant excitation reveals features,
which are not observable in off-resonant PES, by massive enhancement of cross sections
and the different nature of the resonant process [3].
Particularly the electron-vibration coupling, which leads to a characteristic line shape of
molecular orbitals in PES [4], is highly sensitive to interface interaction. We present ResPES
investigations of organic thin films on metal substrates that reveal differences of the photon
energy dependent electron-vibration coupling depending on the interfacial bonding within the
physisorptive regime. Such differences are not visible in off-resonant PES. We show that the
planar copper-phthalocyanine (CuPc) exhibits a quenching of molecular vibrations on
Au(111) with respect to bulk spectra while the non-planar tin-phthalocyanine (SnPc) does
not. Interestingly for both molecules an enhancement of the vibronic loss tail with respect to
bulk spectra is observed at the hetero-organic interface to 3,4,9,10-perylene-tetracarboxylicdianhydride (PTCDA) [3]. Moreover the comparison of ResPES spectra of a submonolayer of
Coronene with the respective bulk spectra reveals an equal photon energy dependent
electron-vibration signature in the first resonance and differences in the second resonance of
the near edge X-ray absorption spectrum.
Our work demonstrates that ResPES provides a very sensitive tool to investigate the
interaction at molecule-metal and hetero-molecular interfaces. In contrast to optical
spectroscopy the site-selective excitation in ResPES additionally allows to gain local
information.
REFERENCES
1.
2.
3.
4.
Bendounan et al., Surface Science 601 (2007) 4013–4017
Föhlisch et al., Nature, Vol 436, 21 July 2005, 373–376
Häming et al., Chemical Physics Letters 510 (2011) 82–86
Kera et al., Progress in Surface Science 84 (2009) 135–154
PO-18
Many Body Effects in the Resonant Photoelectron
Spectra of Metal-organic Interfaces
A. Schöll, C. Sauer, M. Häming, M. Wiessner,
M. Scholz and F. Reinert
Universität Würzburg, Experimentelle Physik VI, Am Hubland, D-97074 Würzburg
and
Gemeinschaftslabor für Nanoanalytik, Karlsruher Institut für Technologie KIT, D-76021 Karlsruhe
ABSTRACT
Resonant photoelectron spectroscopy (ResPES) allows probing the electronic structure of
surfaces and interfaces in conjunction with local information enabled by the site-selective
absorption [1]. Furthermore it provides access to the time domain on the fs- and even asscale with the core-hole clock technique [2] and thus allows quantitatively investigating
charge transfer (CT) at interfaces. Moreover, the resonant excitation reveals features, which
are experimentally not accessible in off-resonant PES, by a massive enhancement of cross
sections and the different nature of the resonant process [3].
In this work we have investigated organic molecules adsorbed on metal substrates by
ResPES with particular respect to the influence of the substrate, charge transfer processes,
and the effect of many body processes.
For all investigated systems characteristic new constant final state (CFS) features appear
in the ResPES spectra of the interfacial layers, which are absent for the respective bulk
spectra and can thus be immediately related to the metal-organic interface.
In case of a weak metal-molecule bonding and subsequently negligible CT in the ground
state, these CFS features can be explained by final states that involve CT from the metal into
the molecule and subsequent Auger decay [4]. However, for organic-metal interfaces where
CT into the lowest unoccupied molecular orbital (LUMO) occurs already in the ground state
this stepwise single particle picture fails to explain such CFS features.
Moreover, continuous energy loss tails are observed for the molecular features in the
latter systems. These broad signals show intensity maxima entirely at odds with direct PES.
In particular cases resonant excitation may even lead to additional features at low binding
energy, which can be explained by charge transfer from the substrate into the LUMO.
When discussing possible origins of our experimental findings we demonstrate that a
single particle picture [5] is insufficient to describe the complicated effects occurring at metalorganic interfaces.
REFERENCES
1.
2.
3.
4.
5.
Bendounan et al., Surface Science 601 (2007) 4013–4017
Föhlisch et al., Nature, Vol 436, 21 July 2005, 373–376
Häming et al., Chemical Physics Letters 510 (2011) 82–86
Taylor et al., J. Chem. Phys. 127, 134707, 2007
Brühwiler et al., Rev. Mod. Phys., Vol. 74, No. 3, July 2002
PO-19
Formic and Acetic Acid: Valence Threshold
Photoelectron and Photoionisation Total Ion Yield
Studies and Discussion on their Relative Acidity
M.R.F. Siggel-Kinga*, A.J. Yenchab, G.C. Kingc,
A.E. R. Malinsa, M. Eypperd
a
Cockcroft Institute, Daresbury Science and Innovation Campus, Daresbury, Warrington, WA4 4AD,
UK and the Department of Physics, University of Liverpool, UK
b
Department of Chemistry, State University of New York at Albany, Albany, New York 12222, USA
c
Department of Physics and Astronomy and Photon Science Institute,
Manchester University, Manchester M13 9PL, UK
d
School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
ABSTRACT
The carboxylic acids (formic and acetic) have been studied using threshold photoelectron
(TPE) and total photoion yield (TPIY) spectroscopies; simultaneously obtained spectra of
formic acid (HCOOH) were recorded over the entire valence ionisation region from 11-21 eV
at a resolution of ~12 meV. Higher resolution spectra (~6 meV) were also obtained in the
energy region of the lowest two cationic states. Analysis of the TPE spectrum in this energy
range agreed very favorably with the best available conventional photoelectron (PE)
spectrum of formic acid. Autoionising Rydberg structure was observed in the TPIY spectrum
of formic acid and is attributed primarily to the presence of the npa' ← 8a' Rydberg series
converging on to the 32A' ionic state of formic acid. Preliminary results, at a resolution of
~8 meV, were obtained for acetic acid (CH3COOH) over the onset of the ionisation energy
region. The TPE spectrum was found to be very similar to the best published photoelectron
spectrum, but no Rydberg structure was observed in the TPIY spectrum.
In the gas-phase, formic acid is a stronger acid than acetic acid. The explanation for the
relative acidity of formic and acetic acids has been the topic of several papers over the years
(see for example refs 1-6); based on the discussions in these papers, it appears that a
satisfactory explanation had yet to be agreed. We will compare and discuss some of these
various explanations and theories.
REFERENCES
1.
2.
3.
4.
5.
6.
M.R.F. Siggel and T.D. Thomas, J. Am. Chem. Soc., 114, 5795 (1992).
F. Bökman, J. Am. Chem. Soc., 121, 11217 (1999).
O. Exner and Petr Čársky, J. Am. Chem. Soc., 123, 9564-9570 (2001).
J. Holt and J. M. Karty, J. Am. Chem. Soc., 125, 2797 (2003).
J.A. Streitwieser and I. C. Wan, J. Phys. Chem., 115, 13072 (2011).
S. Böhm, O. Exner, New J. Chem., 29, 336-342 (2005).
PO-20
S2p photoabsorption and ES-AEPICO Spectroscopy
of DMDS, a Prototype Molecule for the Study of the
Disulfide Chemical Bonds
G. Simões1,2, R.B. Bernini1, G.G.B. de Souza1, C. Nicolas2,
M. Patanen2 X.J. Liu2 and C. Miron2
1
Instituto de Química, Universidade Federal do Rio de Janeiro, Cidade Universitária,
21941-909, Rio de Janeiro, Brasil
2
Synchrotron SOLEIL, l’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
ABSTRACT
As a starting point to study the interaction of ionizing radiation with biomolecules
containing sulfur-sulfur chemical bonds, we performed a detailed analysis of the electronic
excitation and ionic fragmentation of the CH3SSCH3 (DMDS) molecule, following excitation
and ionization around the S2p edge.
First experiments1 were conducted at the Brazilian National Synchrotron Radiation Source
(LNLS). We here describe here recent experiments performed at the3rd generation French
synchrotron, SOLEIL, on the undulator beamline PLEIADES2 using the coincidence
experimental setup (EPICEA) 3-5. In parallel, total electron yield (TEY) and high-resolution
photoelectron and resonant Auger spectra were obtained using a VG-Scienta R4000
hemispherical electron energy analyzer.
High-resolution electron and mass spectra were obtained below and above the S2p edge
(161.5 eV and 181.5 eV) and at photon energies corresponding to 5 below-threshold
resonances (164.6 eV, 165.9 eV, 167.0 eV, 168.1 eV, and 169.1 eV).
Bands associated with the ionization of the outermost and inner-valence states are
observed in the DMDS photoelectron spectra. Bands related to satellite states (excited singly
charged species) and Auger decay were also observed. The results of the ionic
fragmentation show an increasing degree of fragmentation as we move on from below
resonances to the second and third resonances. Above the ionization edge, normal Auger
processes lead to a strong degree of fragmentation. CHnS+ fragments, which are the
signature of the S-S bond breaking, become the dominant species above threshold.
Formation of the S2+ cation is maximized on the second and third resonances.
Mass-selected photoelectron spectra (MS-PES) demonstrate for instance that while
formation of the molecular ions is basically associated with the outermost valence states, the
observation of S+ fragment is mainly related to the ionization of inner-valence states.
Acknowledgements : The Brazilian agencies CNPq and CAPES for finantial assistance
and the Soleil staff for the highly professional technical support.
REFERENCES
1. Bernini, R. B. et al. J. Chem. Phys. 136 (2012).
2. http://www.synchrotron-soleil.fr/portal/page/portal/Recherche/LignesLumiere/PLEIADES
3. P. Morin, M. Simon, C. Miron, N. Leclercq, D.L. Hansen, J. of Electr. Spectrosc. and Relat. Phenomena 93, 49 (1998).
4. Céolin, D.; Miron, C.; Simon, M.; Morin, P. J. El. Spectr. Rel. Phen. 141 (2004).
5. Miron, C.; Morin, P. Nucl. Instr. Meth. Phys. Res. A. 601 (2009) 66.
PO-21
Synchrotron Radiation Studies Of Hyperthermal
Radicals And Plasma Short-lived Species
M. Alagia1, E. Bodo2, S.Falcinelli3, A. Ponzi2,
R. Richter4, and S. Stranges2,1*
1
IOM-CNR, Laboratorio TASC, I-34149 Basovizza, Trieste, Italy
Dipartimento di Chimica, Università degli Studi di Roma “La Sapienza”,
piazzale Aldo Moro 5, I-00185 Rome, Italy
3
Dipartimento di Ingegneria Civile ed Ambientale, Università degli Studi di Perugia,
Via G. Duranti 93, 06125 Perugia, Italy
4
Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy
2
ABSTRACT
Studies of core electron excitations in short-lived open shell systems, such as
hydrocarbon radicals, have recently been carried out by combining a free radical supersonic
beam source with intense and high resolution synchrotron radiation. The first experimental
and theoretical study of the X-ray absorption spectra (XAS) of hyperthermal hydrocarbon
radicals, such as the allyl (CH2CHCH2) and the methyl (CH3, CD3) free radicals, has been
performed. The intense spectral features in the allyl XAS are due to core excitations localized
either on the central or the terminal carbon atoms. The theoretical assignment of all the
intense experimental features was only possible by adopting a multi-configuration approach
(MCSCF), required because of the open shell nature of the radical molecule (1). The
investigation of the decay dynamics of the allyl dication formed via core excitation revealed a
rich behavior. Emphasis will be given to some aspects like the hydrogen sigmatropic shifts
involved in metastable dication decay channels, and the influence of the core hole
localization on the nuclear decay dynamics.
In the case of the methyl radicals CH3 (2) and CD3 (3), a theoretical and high
resolution experimental investigation of the complex vibronic structure of the lowestlying core excitation process has allowed the first detailed elucidation of an umbrellalike vibrational motion in inner-shell absorption spectroscopy. This study pointed out
the strong anharmonicity of the PES of the core excited state along the symmetrical
bending coordinate due to the characteristic double-well potential.
Short-lived plasma species generated with sufficiently high density have been
investigated by synchrotron-based spectroscopies in the valence and inner-shell
regimes. Results obtained in studies of difluorocarbene, CF2 (4) and carbon sulfide
CS will be described, and perspectives outlined.
REFERENCES
1.
2.
3.
4.
M. Alagia, E. Bodo, P. Decleva, S. Falcinelli, A. Ponzi, R. Richter, S. Stranges, (to be submitted)
M. Alagia et al., Phys. Rev. A, 76, 022509 (2007).
U. Ekström et al., J. Chem. Phys., 128, 044302 (2008).
F. Innocenti et al., Chem. Eur. J., 14, 11452-11460 (2008).
PO-22
Isolated Silicon Nanocrystals Probed
by Synchrotron Radiation Soft X-rays
O. Sublemontier1, C. Nicolas2, M.A. Gaveau1, H. Kintz1, X.J. Liu2,
J.L. Legarec3, J.B.A. Mitchell3, M. Patanen2, E. Robert2,
C. Reynaud1 and C. Miron2
1
2
CEA/IRAMIS/SPAM/Laboratoire Francis Perrin, CEA Saclay, 91191 Gif sur Yvette cedex
Synchrotron SOLEIL, PLEIADES beamline, Saint Aubin - BP 48, 91192 Gif-sur-Yvette cedex
3
Institut de Physique de Rennes - UMR 6251, Université Rennes 1, 35042 Rennes Cedex
ABSTRACT
Novel experimental investigations are currently carried out to explore fundamental
processes involved in the interaction between isolated nano-objects and soft X-ray radiation
[1-3]. This kind of experiment has become possible namely owing to the advanced
instrumentation that is now available, as for instance at the PLEIADES beamline [4] SOLEIL synchrotron radiation facility. In this study, we were able to produce a focused beam
of silicon nanocrystals in vacuum from a stable suspension in ethanol. The synchrotron
radiation crossed the nanoparticle beam at 90° at the focal point of an aerodynamic lens. In
the interaction region, the particle beam diameter and the local particle density are estimated
to be 300 µm and 107 cm-3, respectively. These conditions allowed us to perform X-ray
Photoelectron Spectroscopy (XPS) of isolated surface-oxidized silicon nanocrystals of
different sizes and different natural oxidation times.
All the oxidation states of silicon from Si0 to Si4+ are present in our XPS spectra, denoting
a shallow transition between the Si-core and the oxide shell of the particle. Moreover clear
shifts of the whole XPS spectrum are observed towards higher bending energies as oxidation
time increases, which could reveal strong interfacial Si/SiO2 interaction and compressive
stress arising upon oxidation [5]. Complementary studies on the same samples using HighResolution Transmission Electron Microscopy, Fourier-Transform Infrared spectroscopy and
tabletop XPS measurements of deposited samples will also be discussed. Finally, the
specificity of studying isolated nano sized particles will be highlighted.
REFERENCES
1. J. Meinnen et al., Rev. Sci. Instrum 81 (2010) 085107
2. E. R. Mysak et al., Rev. Sci. Instrum 81 (2010) 016106
3. X.J. Liu et al., in manuscript
5. Hofmeister et al., Eur. Phys J. D 9 (1999) 137……..
PO-23
The ESCA Molecule
Historical Remarks and New Results
O. Travnikovaa, K.J. Børveb, M. Patanena, J. Söderströmc,
C. Mirona, L.J. Sæthreb, N. Mårtenssonc, S. Svenssonc
a) Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP 48,
91192 Gif-sur-Yvette Cedex, France
b) Department of Chemistry, University of Bergen, Allegaten 41, NO-5007 Bergen, Norway
c) Department of Physics and Astronomy, Uppsala University, SE-751 20 Uppsala, Sweden
ABSTRACT
The C1s photoelectron spectrum of ethyl trifluoroacetate (CF3-CO-O-CH2-CH3), also
known as the ÈSCA molecule', is the most illustrative showcase of chemical shifts in
photoelectron spectroscopy /1-3/. The binding energies of the four carbon atoms of this
molecule spread over more than 8 eV with energy separations ranging from 1.7 to 3.1
eV owing to different chemical environments and hence different charge states of these
chemically identical atoms. In this contribution we discuss the history and importance of
this spectrum in the field of photoelectron spectroscopy starting from the time of
invention of the ESCA technique.
We present a new very highly resolved version of this spectrum, obtained at the
PLEIADES beamline at SOLEIL. The result shows that we have to use the most modern
experimental and computational tools to observe the important details and to describe
the spectrum theoretically. Large geometrical changes, different for each ionization site,
and the presence of two conformers of ethyl trifluoroacetate influencing the spectral
lineshapes of all four C1s lines can be observed. Also we show that dissociation occurs
for C1s ionization of one of the carbon atoms. All these effects have been carefully
modeled by theory and investigated in the experimental spectrum.
Finally the relative cross sections for the different C1s levels has been measured as a
function of photon energy. Large oscillations have been observed which will be
discussed.
REFERENCES
1. K. Siegbahn, C. Nordling, A. Fahlman, R. Nordberg, K. Hamrin, J. Hedman,G. Johansson, T. Bergmark, S.-E. Karlsson, I. Lindgren,
B. Lindberg,ESCA, Atomic, Molecular and Solid State Structure Studied byMeans of Electron Spectroscopy, Almqvist and Wiksells, Uppsala,
1967.
2. K. Siegbahn, K. Nordling, G. Johansson, J. Hedman, P. Hed_en, K. Hamrin, U. Gelius, , L. W. T. Bergmark, R. Manne, Y. Baer, ESCA
Appliedto Free Molecules, North-Holland, Amsterdam/London, 1969
3. U. Gelius, E. Basilier, S. Svensson, T. Bergmark, K. Siegbahn, J. ElectronSpectrosc. Relat. Phenom. 2 (1973) 405
PO-24
Valen
nce-shell Pho
otoelec
ctron Circularr Dichro
oism (P
PECD)
o
on Gas Phase
e Alanin
ne
M. Tia1, B. Cun
nha de Miranda1, F
F. Gaie-Le
evrel, G. Garcia1,
1
2
L. Nahon and II. Powis
1
Synchrotron SOLEIL,
S
S
L’Orrme des Merrisiers, St. Au
ubin, B.P.48, 91192 Gif su
ur Yvette, Fra
ance
2
School of Chemistry,
C
U
University
of N
Nottingham, N
Nottingham N
NG7 2RD, Un
nited Kingdom
ABSTRACT
T
otoelectron Circular Dicchroism (PE
ECD) is obsserved as a forward/backward asyymmetry, with
Pho
respect to the photon axis, of the
e photoelecctron angula
ar distributio
ons resulting
g from the CPL-induce
ed
ation of gass phase pure
e enantiome
ers of a chirral species. This specta
acular orbita
al-dependent
photoioniza
chiroptical effect with intensities reaching u
up to the fe
ew tens off %, show
ws a rich ph
hoton energ
gy
pears as a vvery sensitiive probe o
of molecularr conformattion and of the chemiccal
dependencce, and app
environmen
nt.1 After the study of n
numerous organic
o
com
mpounds we
e present he
ere the first PECD stud
dy
on biomole
ecules, morre preciselyy amino-acid
ds, the building blockss of proteins with the showcase of
alanine, the
e simplest cchiral proteicc amino-acid in the firstt few eVs ab
bove the IP located at 8
8.82 eV.
oincidence imaging sspectromete
er
Experiments were cconducted using the new elecctron/ion co
S 3, which records Ang
gle-Resolve
ed photoelectron spectroscopy on mass-seleccted sample
es
DELICIOUS
to extract the PECD. F
Fragment-frree neutral alanine molecules werre produced
d by thermodesorption of
ponding hom
mochiral aerosol, accorrding to a method
m
that we recentlyy developed
d on DESIR
RS
the corresp
in order to
o bring in th
he gas pha
ase fragile species.2 B
By alternatin
ng right- an
nd left-hand
ded circularrly
polarized radiation,
r
th
he photoele
ectron circular dichroism (PECD
D) in the a
angular disttribution wa
as
extracted ffrom the ele
ectron imag
ges obtained
d by coincid
dence with the ions co
orrespondin
ng to alanine:
parent (m/zz = 89) and fragment (m
m/z = 44 and 45), rejeccting the spu
urious contribution from
m N2 and NO
O.
Analysiss of the corrresponding
g images allowed us to
t observe a
clear “m
mirroring” between the ttwo enantiomers at diffferent photo
on
energiess and to qu
uantify the forward/bac
f
kward
a
asymmetry
of
photoele
ectrons, rea
aching up to
o 6 % at th
he lyman
wavelength
(See Fig
gure).
Figu
ure: raw differen
nce (lcp-rcp)
photo
oelectron image
es of D-alanine.
Recent Co
ontinuum Multiple Scatttering (CMS-Xα) calcculations co
ompared to data at se
everal photo
on
nd for several orbitals should allow
energies an
w us to provvide a confo
ormational a
analysis of tthe produce
ed
gas phase molecules. Finally, these data will be discusssed within the contextt of exobiolo
ogy since it is
e to explain
n a possible
e enantiome
eric enrichm
ment of amiino-acids de
elivered on the primitivve
a candidate
3
Earth, leading to life’s homochirality, i.e. the fact
f
that onlly L-amino a
acids are found in the biosphere.
b
R
REFERENC
CES
1
2
3
L. Na
ahon and I. Powiss, in Chiral recog
gnition in the gas phase, edited byy A. Zehnacker (C
CRC Press - Tayllor & Francis, Bo
oca Raton, 2010),,
pp. 1
F. Ga
aie-Levrel, G. Ga
arcia, M. Schwell, and L. Nahon, P
Phys. Chem. Che
em. Phys. 13, 702
24 (2011).
L. Na
ahon, G. Garcia, I. Powis, U. Meie
erhenrich, and A. Brack, SPIE Pro
oceedings : "Intru
uments, Methods, and Missions fo
or Astrobiology X""
6694
4, 69403 (2007).
PO-25
New Routes to Ultrafast Dissociation
of Polyatomic Molecules
O.Travnikova1, V. Kimberg1, R. Flammini2, X.J. Liu1, M. Patanen1,
C. Nicolas1, S. Svensson3, and C. Miron1
1
Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48,
F-91192 Gif-sur-Yvette Cedex, France
2
IMIP-CNR Istituto di Metodologie Inorganiche e dei Plasmi, 00019 Monterotondo Scalo, Roma, Italy
3
Department of Physics, University of Uppsala, Box 530, 75121 Uppsala, Sweden
ABSTRACT
Understanding mechanisms of chemical reactions is the essence of chemistry and the key
to their control. However, even dissociation dynamics, the simplest type of chemical
reactions, - can be obscure, especially in the case of complex molecular species with
numerous degrees of freedom.
It is known that dissociation can be competitive to electronic relaxation (i.e. Auger decay)
of the core-hole states created by soft X-ray photons. This phenomenon, called ultrafast
dissociation (UFD), was extensively studied for the last 25 years in a number of molecular
systems (e.g. HCl, O2, O3, H2O, H2S, NH3, SF6, CH3Cl etc. [1]) starting from its discovery in
HBr following the Br3d→ σ* resonant excitation [2]. In all these cases, the lifetime of the
core-hole states is very short, ranging between 3 to 8 fs, and sets the available time span for
the photodissociation process to take place. Therefore, all detailed studies of UFD involved
relatively light molecules, where the reduced mass of the dissociating system allows
fragments to travel far enough during the core-hole lifetime to reach the complete breakage
of the chemical bond. It was demonstrated with the help of quasi-classical models that
dissociation rate decreases with increasing the reduced mass of the molecules. UFD was not
observed for Cl2 at the Cl2p-to-sigma* resonance, where the dissociation is slow due to the
high reduced mass of the departing Cl-atoms [3]. The dissociation in the case of even larger
molecules, such as 1-bromo-2-chloroethane (Br(CH2)2Cl, BCE) should be correspondingly
slower than that in Cl2. Despite this prediction, the signatures of UFD were observed for Cl2p
and Br3d core-excited states of BCE in the gas phase. This observation suggests that
alternative dissociation pathways should exist in case of complex, polyatomic species
enabling bond breakage on shorter timescales beyond the point-mass approximation.
We present a new dissociation mechanism of UFD, elaborated from the analysis of the
ultrafast nuclear dynamics in core-excited BCE. It implies that in large molecular systems,
which yield heavy fragments after dissociation, bond breakages can occur on very short time
scales owing to the internal motion of light linkages. This alternative mechanism should be
rather general for large molecular systems.
REFERENCES
1. M. Quack and F. Merkt, Handbook of High-Resolution Spectroscopy (John Wiley & Sons Ltd, Chichester, UK, 2011), chap. Highresolution Inner-shell Photoionization, Photoelectron and Coincidence Spectroscopy by C. Miron and P. Morin, pp. 1655–1690.
2. P. Morin and I. Nenner, Phys. Rev. Lett. 56, 1913 (1986).
3. E. Kukk et al. J. Chem. Phys. 104, 4475 (1996)
LIST OF PARTICIPANTS
HRSIS 2012 "High Resolution Spectroscopies of Isolated Specie: present and futures directions " ‐ September 14th‐15th, 2012 List of participants
Name
ALMEIDA
ALSHORMAN
AVALDI
BARREDA
BECKER
BERGERSEN
BIZAU
BOMME
BOWEN
BOZEK
CARNIATO
CARROLL
CEOLIN
CZASCH
DECLEVA
DOWEK
EBERHARDT
GEJO
GELMUKHANOV
GUILLEMIN
HERGENHAHN
JOURNEL
KAWERK
KENNEDY
KIMBERG
KIVIMAKI
KIYOSHI
KUKK
KUMAR
KUSHAWAHA
LABLANQUIE
LIU
MARCHENKO
MARGGI POULLAIN
MARTENSSON
MCLAUGHLIN
MIRON
MORIN
MOUSTAFA
MOXON
NAHON
NICOLAS
PALAUDOUX
PATANEN
PAVLYCHEV
PENENT
Surname
Guilherme
Mohammad
Lorenzo
Flory-Anne
Uwe
Henrik
Jean-Marc
Cedric
Kyle
John David
Stéphane
Thomas
Denis
Achim
Piero
Danielle
Wolfgang
Tatsuo
Faris
Renaud
Uwe
Loïc
Elie
Eugene
Victor
Anti
Ueda
Edwin
Vinod
Rajesh Kumar
Pascal
Xiaojing
Tatiana
Sonia
Nils
Brendan
Catalin
Paul
Mohamed
Elisabeth
Laurent
Christophe
Jérome
Minna
Andrey
Francis
Institue
Universidade Federal do Rio de Janeiro
Institut des Sciences Moléculaires d'Orsay
Istituto di Metodologie Inorganiche e dei Plasmi
CEA Saclay
Fritz-Haber-Institut der Max-Planck-Gesellschfat
VG SCIENTA
ISMO and Synchrotron SOLEIL
Laboratoire de Chimie Physique - Matière et Rayonnement
SLAC/LCLS
Keuka College
Synchrotron SOLEIL
RoentDek Handels GmbH
University of Trieste
ISMO
DESY-CFEL
University of Hyogo
Royal Institute of Technology
Max-Planck-Institute for Plasma Physics
Dublin City University
Max Planck Advanced Study Group at CFEL, DESY
CNR-IOM, TASC Laboratory
IMRAM, TOHOKU UNIVERSITY
Univeristy of Turku
National Institute of Technology Hamirpur (H.P)
LCP-MR, CNRS & Université Pierre et Marie Curie
Synchrotron SOLEIL
Institut des Sciences Moléculaires d'Orsay
Uppsala University
Queen's University Belfast
Synchrotron SOLEIL
Synchrotron SOLEIL
Humboldt Universität zu Berlin, Institut für Physik
ALS Communication
Synchrotron SOLEIL
Synchrotron SOLEIL
Synchrotron SOLEIL
St. Petersburg State University
Town
Rio de Janeiro
Orsay
Monterotondo Scalo
Gif-sur-Yvette
Berlin
Uppsala
Orsay
Paris
Paris
Menlo Park
Paris
New York
Gif-sur-Yvette
Kelkheim
Treiste
Orsay
Hamburg
Hyogo
Stockholm
Paris
Berlin
Paris
Paris
Dublin
Hamburg
Trieste
Sendai
Turku
Hamirpur
Paris
Paris
Paris
Paris
Orsay
Uppsala
Belfast
Gif-sur-Yvette
Gif-sur-Yvette
Berlin
Berkeley
Gif-sur-Yvette
Gif-sur-Yvette
Paris
Gif-sur-Yvette
St. Petersburg
Paris
Country
Brazil
France
Italy
France
Germany
Sweden
France
France
France
USA
France
USA
France
Germany
Italy
France
Germany
Japan
Sweden
France
Germany
France
France
Ireland
Germany
Italy
Japan
Finland
India
France
France
France
France
France
Sweden
United Kingdom
France
France
Germany
USA
France
France
France
France
Russia
France
Email
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HRSIS 2012 "High Resolution Spectroscopies of Isolated Specie: present and futures directions " ‐ September 14th‐15th, 2012 PIANCASTELLI
POLIAKOFF
PRINCE
PUTTNER
REYNAUD
ROCCO
RUBENSSON
RÜHL
SAETHRE
SIGGEL-KING
SIMÕES
SIMON
SODERSTROM
STEFANO
SUBLEMONTIER
SVENSSON
THOMAS
TIA
TRAVNIKOVA
UEDA
VOSS
ZAHL
Maria Novella
Erwin
Kevin Charles
Ralph
Cécile
Maria Luiza
Jan-Erik
Eckart
Leif
Michele
Grazieli
Marc
Johan
Stranges
Olivier
Svante
Darrah
Maurice
Oksana
Kiyoshi
Stefan
Maria
Louisiana State University
Sincrotrone Trieste ScpA
Freie Universität Berlin
CEA
Institute of Chemistry, Federal University of Rio de Janeiro
Department of Physics and Astronomy
Freie Universität Berlin
University of Bergen
Cockcroft Institute and University of Liverpool, Department of Physics
Synchrotron SOLEIL
Department of Physics and Astronomy
Department of Chemistry, University of La Sapienza, Rome, Italy
CEA - IRAMIS
Dept. of Physics and Astronomy
Oregon State University
Synchrotron SOLEIL
Synchrotron SOLEIL
IMRAM, Tohoku University
RoentDek Handels GmbH
University of Bergen, Dep. of Chemistry
Paris
Baton Rouge, LA
Trieste
Berlin
Gif-sur-Yvette
Rio de Janeiro
Uppsala
Berlin
Bergen
Warrington
Gif-sur-Yvette
Paris
Uppsala
Rome
Gif-sur-Yvette
Uppsala
Corvallis
Gif-sur-Yvette
Gif-sur-Yvette
Sendai
Kelkheim
Bergen
France
USA
Italy
Germany
France
Brazil
Sweden
Germany
Norway
United Kingdom
France
France
Sweden
Italy
France
Sweden
USA
France
Gif-sur-Yvette
Japan
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Norway
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HRSIS 2012 - September 14 - 15, 2012 - Program Overview
Time
Friday 14
Time
Saturday 15
Session 3 - Chair: P. Lablanquie
12h00 - 14h00
Registration
12h00 -13h00
Lunch
13h00 - 14h00
SOLEIL Tour
(for registered participants)
14h00 - 14h15
Welcome - C. Miron
9h00 - 9h45
Recoil and Related Effects in Molecular Photoemission
E. Kukk (Invited talk)
9h45 -10h15
F. Gel’mukhanov (Invited talk)
10h15 -10h45
High Resolution Molecular Spectroscopy Using Electron-Electron Coincidence Techniques
U. Hergenhahn (Invited talk)
10h45 - 11h15
Coffee Break
Session 1 - Chair: M.N. Piancastelli
14h15 -15h00
Electron Spectroscopy And Chemical Properties Past And Present
L.J. Sæthtre (Invited talk)
Session 4 - Chair: J.E. Rubensson
15h00 - 15h30
30 Years of Electron Spectroscopy with T. Darrah Thomas
T. Carroll (Invited talk)
15h30 - 15h45
Resonances In Inner-Shell Photoemission From Isolated Endohedral Systems
A. Pavlychev (Oral Communication)
15h45 - 16h00
A Novel Method to Derive Electronegativity from Resonant Inelastic X-ray Scattering:
beyond Pauling, Mulliken and XPS scales
S. Carniato (Oral Communication)
16h00 - 16h30
11h15 - 11h45
Non Franck-Condon Processes in Molecular Photoionization
E. Poliakoff (Invited talk)
11h45 - 12h15
Theoretical Studies Of The Non Born-Oppenheimer Phenomena Observed In Molecular
RAS And RIXS Spectroscopy
V. Kimberg (Invited talk)
Coffee break
Session 2 - Chair: N. Mårtensson
12h15 -12h30
12h30 -12h45
16h30 - 17h00
Double Core-Hole Spectroscopy – Experimental Aspects
F. Penent (Invited talk)
12h45 - 14h00
17h00 - 17h30
17h30 - 18h00
Extracting Chemical Information of Free Molecules from K-shell Double Core-hole
Spectroscopy : Theoretical Aspects
K. Ueda (Invited talk)
Lunch
Session 5 - Chair: S. Svensson
14h00 - 14h30
A Tale Of Resonant Auger Spectroscopy Seen (Mostly) From The Point Of View Of The
N2 Molecule
A. Kivimäki (Invited talk)
14h30 - 15h00
High-resolution Auger spectroscopy: A powerful tool to study metastable molecular
dications
R. Püttner (invited talk)
15h00 - 15h30
P. Morin (Invited talk)
High-Resolution Electron Spectroscopy at the ALS – A New Beginning
J.D. Bozek (Invited talk)
18h00 - 18h15
L. Avaldi (Oral Communication)
18h15 - 18h30
Multi Electron Coincidence Spectroscopy Of Atomic Mercury
J. Palaudoux (Oral Communication)
18h30 - 20h00
Massive Franck-Condon Breakdown Investigated By Vibrationally-Resolved
Photoionization of Chiral Molecules With Circular-Polarized Light
L. Nahon (Oral Communication)
High-Resolution Angle-Resolved Ro-Vibrational Autoionisation Of Ortho-D2 Involving
Transitions Beyond The Born-Oppenheimer Approximation
M. Siggel-King (Oral Communication)
Poster Session and Cocktail
15h30 - 16h00
Coffee Break
Session 6 - Chair: K. Prince
20h15 - 22h00
16h00 - 16h30
High Energy Structures in Molecular Photoionization
P. Decleva (Invited talk)
16h30 - 17h00
High-resolution Electron Spectroscopy: Cross Sections And Asymmetry Parameters In
Complex Species
M. Patanen (Invited talk)
17h00 - 17h15
Accurate Carbon 1s Hole-State Lifetimes for Chlorinated Methanes
M. Zahl (Oral Communication)
17h15 - 18h00
Conclusions by Prof. T. Darrah Thomas
Diner
End of the Workshop

the Abstract book

Transcription

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