On-line Laser spectroscopy of Ac isotopes at LISOL and status of KU

On-line in-gas laser
spectroscopy of Ac
and status of the IGLIS lab
at KU Leuven
Simon Sels
Colloque de GANIL, Anglet
12 October 2015
Outline
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S3-LEB
In-gas laser ionization & spectroscopy (IGLIS)
Laser ionization and spectroscopy tool
First online results in the heavy-mass region: Ac
Further development at KU Leuven: IGLIS Lab
Outlook
S3-LEB and REGLIS3
S3-LEB and REGLIS3
S3-LEB
MR-TOF MS
REGLIS3 @ SPIRAL2
REGLIS3
MCP
MR ToF
(m/Dm ~ 105)
gas inlet
gas cell
S-shape RFQ
diff. pumping
RFQ
QMF
(m/Dm ~ 100)
buncher
bender
detector
station
EVRs
Neutralized EVRs
Photoions
from
S3
towards DESIR
l1,2
in-gas-cell
ionization
l2
in-gas-jet
ionization
l1
R. F. et al., NIM B 317 (2013) 570
In-Gas Laser Ionization & Spectroscopy
developments: HELIOS @ KU Leuven
• Production
• Laser spectroscopy
Ground and Isomeric state properties
Spins
Moments
Charge radii
Advantages of in-gas-jet LIS
Precise
(High spectral resolution ~ 200 MHz)
low P, low T, well defined 𝑣 in
supersonic jet reduces pressure- and
Doppler broadening of line shapes
Sensitive
(low production rates: <1 pps)
expected efficiency including S3 transmission: 4-24% [1]
Selective
(eliminate contaminants: 1/10000)
Fast
(short half-lives: Delay time ~ 200 ms)
Extraction from gas cell is independent of
chemical properties
[1] R. Ferrer. et al., NIM B 317 (2013) 570
Advantages of IGLIS at S3
Courtesy to A. Drouart
S3 provides :
o High intensity beams
o No primary beam in gas cell
o Purification with S3 (Converging / 1 Charge state mode)
Heavy ion fusion reactions –
Complementary to other RIB facilities
Coupling this to S3 will open up new experimental regions
on nuclear chart
Laser ion source and spectroscopic tool
Refractory
elements
N=Z nuclei
VHE – SHE
Understand nuclei at
limit of existence
Coupling to S3 will open up possibility to study
underexplored regions of nuclear chart:
[1]
[1] K. Blaum et al. Phys. Scr. T152 (2013) 014017.
First online results: Ac at LISOL
Measure alpha decay
In gas cell
Max 200 Hz
First online results: Ac at LISOL
In gas jet
Mainz + Jyvaskyla + GANIL lasers
Max 10 kHz
First online results: Ac at LISOL
IN GAS CELL
First online results: Ac at LISOL
IN GAS CELL VS IN GAS JET
Preliminary results
Doppler Broadening (MHz)
In-jet spectroscopy results in:
25-fold improvement in uncertainties of
isotope shifts and magnetic HF constant A
access to quadrupole moments as well
Alpha counts in 50 s
Zoom in on triplet peak in HFS of
214Ac
75
50
25
0
22802.98
22803.00
22803.02
22803.04
-1
Wavenumbers (cm )
22803.06
Velocity (m/s)
Alpha counts in 50 s
Preliminary results
Doppler Broadening (MHz)
Velocity (m/s)
In-jet spectroscopy results in:
25-fold improvement in uncertainties of
isotope shifts and magnetic HF constant A
access to quadrupole moments as well
Zoom in on triplet peak in HFS of
214Ac
75
50
CELL
JET
25
FWHM= 6 GHz
FWHM= 400 MHz
(Resolution ~ 5e-7)
0
Selectivity ~ 80
Selectivity ~ 200
Efficiency ~ 1 %
Efficiency ~ 0.5%
22802.98
22803.00
22803.02
Wavenumbers (cm-1)
22803.04
22803.06
Many possibilities for improvement
spatial
Nozzle
Gas Jet
Scale 55 mm
• Only 10 % of atoms irradiated in current setup (spatial)
-> Can increase efficiency with factor 10
• Prototype nozzle used
• Ambiant gas pressure too low (Jet expansion)
Full characterization of technique needed
High repetition laser setup at LISOL
Equipment from
GANIL – MAINZ – JYFL
Conclusions from first results
• High resolution in-gas-jet laser ionization spectroscopy tested
for first time in on-line conditions at LISOL on 214,215 Ac
• Promising results with this prototype setup in non-optimal
conditions
o Resolution increased order of magnitude
o Efficiency 0,5 %, but with large improvement possible
• In-gas-jet LIS technique will be able to provide high-purity
isomeric beams for S3 LEB
• Characterization in new IGLIS laboratory needed to fully
understand and optimize technique
IGLIS Laboratory @ KU Leuven
Laser laboratory : Operational
Atomic beam unit
Dye laser
Pump
laser
CW
diode laser
2-step
dye amplifier
Separator laboratory Vacuum chamber holding gas cell & RFQ’s
Camera
and intensifier
to record jet
formation using
PLIF technique
Laser-induced
fluorescence in
acetone Jet
Gas cell
Outlook
• Optimization of in-gas-jet technique at IGLIS laboratory
o
o
Characterization of gas jet formation (PLIF)
Capture of photo-ions in RFQ
• Ionization scheme development with ABU
• Online experiments at S3
Thank you for your attention
S. Sels 1 , B. Bastin 2 , D. Boilley 2 , P. Dambre 6 , P. Delahaye 2 , P. Duchesne 6 ,
R. Ferrer 1 , X. Fléchard 3 , S. Franchoo 6 , L. Gaffney 1 , L. Ghys 8 ,
C. Granados 1 , R. Heinke 4 , L. Hijazi 2 , M. Huyse 1 , M. Laatiaoui 7 , J. Lory 3 ,
T. Kron 4 , Y. Kudryavtsev 1 , N. Lecesne 2 , R. Leroy 2 , H. Lu 2 , F. Lutton 2 ,
Y. Martinez 1 , Y. Merrer 3 , E. Mogilevskiy, I. Moore 5 , P. Nauberreit 4 ,
B. Osmond 2 , J. Piot 2 , O. Pochon 6 , S. Raeder 1 , S. Rothe 9 , H. Savajols 2 ,
P. Schoenberg 4 , V. Sonnenschein 5 , J.C. Thomas 2 , E. Traykov 3 ,
P. Van den Bergh 1 , P. Van Duppen 1 , K. Wendt 4 , S. Zadvornaya 1
1
KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven, Belgium
2
3
GANIL, CEA/DSM-CNRS/IN2P3, B.P. 55027, 14076 Caen, France
LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, 14050 Caen Cedex 04, France
4 Institut
für Physik, Johannes Gutenberg Universität, 55128 Mainz, Germany
5JYFL,
6
Institute de Physique Nucléaire (IPN) d'Orsay, 91406 Orsay, Cedex, France
7
8
Department of physics, FI-40014 University of Jyväskylä, Finland
GSI-Darmstadt, Planckstraße 1, 64291 Darmstadt, Germany
SCK_CEN, Belgian Nuclear Research Center, Boeretang 200, 2400 Mol, Belgium
9
ISOLDE RILIS, CERN, Geneva, Switserland
IPN Orsay –LPC Caen – GANIL – Univ Mainz – Univ Jyvaskyla – GSI – KU Leuven