O - Univap

ISWA – 3-8 July 2016
Sputtering analysis of astrophysical solids by
Plasma Desorption Mass Spectrometry - PDMS
E. F. da Silveira, J.M. da Silva Pereira, C.R. Ponciano.
(Master Dissertation- 2015)
Solar das Andorinhas - 2016
Van de Graaff Lab.
1
ISWA – 3-8 July 2016
Sputtering analysis of astrophysical solids by
Plasma Desorption Mass Spectrometry - PDMS
1- Optical Spectroscopies – the main source of information
2- How Mass Spectrometry can be used in Astrophysics?
3- MS of cosmic rays
4- Mass spectrometers in space
5- MS of cosmic samples (our data)
6- MS of analogues (our data)
7- Final Comments
Solar das Andorinhas - 2016
Van de Graaff Lab.
2
Because sources are too distant ,
Guarujá - 2013
most of the information from the Universe comes by electromagnetic waves
3
Ex.: image acquired by the Very Large Telescope, Chile
VLT image
Thor’s Helmet Nebula
(near Sirius – Canis Major)
The blue color reveals an oxygen cloud expanding
VLT image
Thor’s Helmet Nebula
(near Sirius – Canis Major)
Optical Spectroscopies are very important but, nevertheless,
Relevant cosmic information also comes via:
- gravitation (now: waves !)
- neutrinos
- electrons
- cosmic rays (ions)
- cosmogenic and cosmic materials
- space missions
More analytical techniques are necessary, in particular
Mass Spectrometry (MS)
How MS can be used in Astrophysics?
Direct use:
a) cosmic rays* arriving on Earth and on artificial satellites
b) secondary ions produced by natural ionizing radiation
impinging on planets, satellites, grains, asteroids and comets
c) cosmogenic materials (e.g. 14C produced in atmosphere)
d) cosmic samples (measurements in situ) and meteorites
or material brought to Earth by missions
Indirect use:
study of cosmic analogue samples
laboratory data
* Primary CR: e-, H, He and heavy (C → Fe) ions; Secondary CR: Li, mesons, e+
How MS can be used in Astrophysics?
mass determination of:
Mass Spectrometry →
elementary particles, atoms and molecules
measurement of their abundance
H
H
100
100
Relative
Abundância
Relativa
Relative
abundance
Abundância abundance
Relativa (%)
(%)
W. Wien
1898
A. Dempster 1918
F. Aston
1919
MS
MS of
of the
the
Espectro
Espectrode
deMassa
Massados
dos
Elementos
ElementosQuímicos
Químicos
no
noUniverso
Universo
10
10
chemical
chemical elements
elements
He
He
11
in
in Universe
Universe
0,1
0,1
0,01
0,01
Mg
O
O Mg
Si
Si S
S
C
C
Na
Na
N
N
Fe
Fe
1E-3
1E-3
Ca
Ca
Ne
Ne
1E-4
1E-4
10
10
20
20
30
30
40
40
50
50
Massa
MassaAtômica
Atômica
Atomic
AtomicMass
Mass
Thomson (1912) : first mass spectrum
How to get his?
8
Primary Cosmic Ray (CR) Species
Reminder:
Galactic cosmic rays
Solar wind
supernova
Galactic CR
Solar wind
Interstellar winds
Heliosphere
Van Allen Belts
VSW = 400c km/s
Vega
Galaxy
Vs = 100 km/s
Vapex = 16 km/s
9
Solar Wind & Galactic CR
16.5 km/s
Solar wind on Earth orbit
MS easy
Galactic cosmic rays
MS difficult
(very large spectrometers)
SW & GCR Energy Distributions
10
Solar Wind & Galactic CR
16.5 km/s
Solar wind on Earth orbit
Galactic cosmic rays
0.1 GeV
The knowledge of
protons
cosmic ray flux is
crucial for planning
life permanence in space*
MS easy
MS difficult
(very large spectrometers)
* Particularly for the long manned missions
11
b) Mass Spectrometers in Space
The Viking Gas Chromatograph Mass Spectrometer
(1971)
A gas chromatograph uses a thin capillary fiber
known as a column to separate different types of
molecules, based on their chemical properties.
→ Searching for Life on Mars
Alpha Magnetic Spectrometer: He / He
Mass: 8.5 ton
Launch: May 2011
AMS @ Internl. Space Station (ISS)
AMS: Searching for antimatter, dark matter and measuring cosmic rays
b) Mass Spectrometers in Space
antiproton / proton ratio
(2015 AMS-02 data)
antiproton secondary production
from ordinary cosmic ray collisions
(expected)
Alpha Magnetic Spectrometer: He / He
AMS @ Internl. Space Station (ISS)
AMS: preparing for Mars mission. Measuring GeV cosmic rays
b) Mass Spectrometers in Space
antiproton / proton ratio
(2015 AMS-02 data)
antiproton secondary production
from ordinary cosmic ray collisions
(expected)
Alpha Magnetic Spectrometer: p / p
_
p
p
antiproton proton
AMS @ Internl. Space Station (ISS)
AMS: 60 billion cosmic ray events after 5 years
b) Mass Spectrometers in Space
flux
protons
helium
data
higher flux at
high energies
prediction
= B r = m v /q
PRL 110
(2013)141102
for masses
for
trajectories
(charges)
energy detector
TOF mass spectrometer
AMS: a magnetic, TOF and position sensitive spectrometer
b) Mass Spectrometers in Space
Mars Science Laboratory
2011
Analyzing the surfaces of rocks and other samples directly on Mars’ surface.
Laser MS of neutral molecules in Mars soil
c)
Cosmogenic materials
n + 14N → 14C + p
14C
→ 14N + e− + νe
τ1/2 = 5730 years
Beta decay
14C
& 12C
sample
The 14C / 12C ratio gives the sample age
c)
Cosmogenic materials
n + 14N → 14C + p
14C
→ 14N + e− + νe
τ1/2 = 5730 years
Beta decay
negative ion source
14C
&
12C
sample
→ instable ion
12CH - → dissociates
2
14N-
14
14C-
The 14C / 12C ratio gives the sample age
→ detected
d)
Cosmic samples
Murchirson meteorite
(Australia – 28 Sep 1969)
mass 128: naphthalene
178: phenanthrene / antracene
IR + pulsed UV laser MS
(thermal desorption + ionization)
Carbonaceous chondrite type – Hanh et al., Science 239 (1988) 1523
d)
Cosmic samples
Moon rocks
Apolo 11 - 1969
Lunar
Mission
Regolith
SiO2 et
al.
Mare Tranquillitatis
Sample
Returned
Year
Apollo 11
22 kg
1969
Apollo 12
34 kg
1969
Apollo 14
43 kg
1971
Apollo 15
77 kg
1971
Apollo 16
95 kg
1972
Apollo 17
111 kg
1972
Luna 16
101 g
1970
Luna 20
55 g
1972
Luna 24
170 g
1976
•maria → basaltic lava → olivine
•highlands → anorthosite
ρ ~ 4 g/cm3
ρ ~ 2.6 g/cm3
anorthite
Armstrong's walk on the Moon ( on the cat's eye)
main ion-solid mechanisms
1- Electron emission
2- Sputtering (neutrals and ions)
3- Chemical reactions
MeV ion
4- Structural modifications
(compaction, amorphyzation,
crystallization, phase transition,
material stress, craters,…)
ICE grain
COMETA
5- Heating and Sublimation
PDMS – Plasma Desorption MS
MCP
conversion
Porta
de
detector Folhafoil
sample
Amostra
holder
alvos
Detector Conversão
(start)
Start
252Cf
e-
o
I
V
o
+
Fission
Fragmentos
Fragments
de fissão 20 kV
Região
de vôo
livre
free field
region
Amplificador
Amplificador
CFD
MCP
detector
Detector
(stop)
Stop
TDC
CFD
Espectro
de massa
mass spectrum
TOF used in our measurements
Sputtering of silicates
- Analyzed by TOF mass spectrometer
- At room temperature
252Cf
free field region
MCP
detector
(start)
MCP
detector
(stop)
sample
PDMS – Plasma Desorption MS
d)
Cosmic samples
color of Moon
28Si:
92%
5%
30Si: 3%
29Si:
Silica / Quartz (from Apollo mission)
d)
Cosmic samples
Silica / Quartz (brought by Apollo mission)
d)
Cosmic samples
Anorthite (brought by Apollo mission)
e)
Cosmic analogue samples
Moon : 3.1 - 3.9 billion years ago
O
ρmoon = 3.3 g/cm3
Si
Si O2
Silica
2.2
Na3 K Al4 Si4 O16
Nepheline 2.6
Ca Al Si3 O8
Anorthite
2.7
Na Al Si2 O6
Jadeite
3.3
(Mg,Fe)2 Si O4
Olivine
4.0
ρ (g/cm3)
Moon silicates
e)
Cosmic analogue samples
nepheline (20 nm) evaporated on a Si wafer (room temperature)
60000
Na+
39/41K+
50000 H+
Counts (arbitrary units)
FF-252Cf on nepheline (Na,K)AlSiO4
Uextraction = +18 kV
(Na2O)Hn+
40000
0 1
NaLi2
+
30000
Al3On+
Li+
20000
Al Si On
10000
2
n=1
Na2+
n=1
+
2
3
4
3
K2+
hexagonal
0
0
20
40
60
80
100
m/z
Nepheline
120
140
160
180
Cosmic analogue samples
e)
FF-252Cf on Na Al
Uextraction = +18 kV
Si2 O6
H+
Si
Al
Na
Na+
Counts (arbitrary units)
15000
12500
10000
Mass spectrum
of positive ions
Mass spectrum
of negative ions
4 mm
7500
5000
39/41K+
H2+
2500
28/29/30SiO 3
0
0
20
40
m/z
60
80
Al(SiO3)2-
AlSiO3-
(Na2O)Hn+
H3+
AlSiO4-
10
Jadeite
80
100
120
m/z
140
160
180
PDMS Analysis of Meteorites
1. Isna (Egipt, 1970)
Chondrite: carbonaceous – CO3
2. Allende (Mexico, 1969)
Chondrite: carbonaceous – CV3
3. Zagami (Nigeria, 1962)
Acondrite: Shergotito (Martian).
PDMS Analysis of Meteorites
Isna meteorite
28u (Si)
0,02
Contagem/min
Counts
(a. u)
Silicon cluster structures
28u (Si)
28u (Si)
242
28u (Si)
28u (Si)
28u (Si)
270
0,01
232
326
284
256
298
0,00
230
240
250
260
270
280
290
300
312
310
320
327
330
m/z
Example :
Positive ion mass spectrum
344
340
340
350
PDMS analysis of meteorites: Isna, Allende and Zagami
0,06
184
184 u : a very stable structure
179
0,04
212
177
157
0,02
Isna
197
153
209
0,00
0,06
184
Counts (a. u.)
Allende
0,04
179
157
167
163 169177
0,02
0,06
0,00
153
179
161
157
197
0,04
Si2O8
212
209
Si
184
177
197
195
199
211
209
215 221
0,02
150
184 u
Zagami
163
169
171
175
Si
(Yu-Hong and Baoxing, 2014)
160
170
180
190
200
210
220
230
mass
Example :
Negative ion mass spectra
PDMS analysis of meteorites: Isna, Allende and Zagami
0,06
184
184 u : a very stable structure
179
0,04
212
177
157
0,02
Isna
197
153
209
0,00
0,06
184
Counts (a. u.)
Allende
Si
0,04
179
157
167
163 169177
0,02
0,06
0,00
153
179
161
157
197
Si
184
0,04
184 u
Zagami
163
177
197
169
171
175
Si2O8
212
209
195
199
211
209
These ion species are actually
215 221
being “produced” and emitted
0,02
150
from interplanetary
grains
space:
(Yu-Hong
and in
Baoxing,
2014)
160
170
180
190
mass
Example :
200
210
220
CR synthesis in ONE impact !!!
230
Negative ion mass spectra
Sputtering of ices
- Analyzed by TOF mass spectrometer
- At cryogenic temperatures
free field region
ion
beam
252Cf
MCP
detector
(e- start)
MCP
detector
(stop)
sample
ICE
MCP
detector
(start)
Van de Graaff Accelerator – PDMS sputtering analysis line
Water positive ions
O
H
H
most abundant emitted ions :
H+ , H3O+
H- , O-, OHHydrogen bridges:
H2O ice ejects
intense series of
ionic clusters
negative ions
main series :
(H2O)nH2O+
(H2O)nO- , (H2O)nOHn > 60
Surface Science, 569 (2004) 149-162
(H2O)n H3O+ emission decreases as the temperature increases!
1
T
Y = Y0 e- k.n
0,1
35K
60K
k
k
yield (ions/impact)
15K
120K
0.232
0,01
0.172
0.124
Lower temperatures:
T
0.147
higher yields !
1E-3
0
2
4
6
8
10
12
14
16
18
20
n
N – 1.5 MeV beam
k – decay parameter
Ammonia - NH3
n > 30
most abundant emitted ions :
positive ions
H+ , NH4+, NH3+
H- , NH2-, NHHydrogen bridges:
H2O e NH3 eject
intense series of
ionic clusters
negative ions
main series :
(NH3)nNH4+
(NH3)nNH2-
Int. J. Mass Spectrom. 253 (2006) 112-121
Ices without H :
Oxygen
~ 65 MeV
252Cf
fission fragments
300
enrichment with
organic molecules
216K
250
target temperature (K)
10K
IIaahh
200
150
157K
75K 125K
30K
IIah
h
a
++
Ial
decrease of
cluster ions
IIaal
Ia l
=0
ddice
ice = 0
100
50
0
100
150
200
250
300
350
400
time (min) after dosing
Molecular clusters are ejected into the gas phase → Radio telescopes ?
Carbon Monoxide - C≡O
graphitization !
CARBON CHAINS
abundants:
C+ , CO+, O+, CO2+
O- , C-, C2dominants:
Cn(CO)2+, Cn(CO)+, Cn+
Cn-, OnTemperatura →
Synthesization : CO3-, C2O3-
Int. J. Mass Spectrom., 251 (2006) 1- 9
Carbon Dioxide - O=C=O
abundants:
O2+ , CO2+, C+, CO+
CO3- , O-
dominants:
(CO2)nO2+
(CO2)nCO3-
J. Am. Soc. Mass Spectrom. 17 (2006) 1120-1128
Mixture O2 + N2
abundants:
O2 + , O+ , O3 + ,
N2+, N+, N3+, NO+
O-, O2- (no N-)
Main series:
(O2)nO2+, (O2)nO+, (O2)nO3+
(N2)nN2+, (N2)nN+
On-, OnN2 Synthesis of:
NO+, NO3+, OnNO+, OnN2+
NO-, N2OJournal of Mass Spectrometry, 43 (2008) 1521-1530
H2O ice Sputtering Yield
J Phys Chem C 115 (2011) 12005
CH4 Radiolysis : FTIR vs MS
C2H6
CH4
C2H4
C2H6
CH3
Astronomy & Astrophysics , A531 (2011) A160
C3H8
CH3OH Radiolysis - FTIR
Formation cross section σf
MNRAS , 418 (2011) 1363
CR impacts : Qualitative Results
Chemistry:
• Hot chemistry (104 K) in very cold material (10 - 100 K)
RT → 1/40 eV ; keV → 4000 K
• Fast chemistry (ps) in solids
No thermodynamical equilibrium
• New pathways for Organic Chemistry:
The bombardment of CO by ions has an interesting and relevant
property: the formation of carbon chains
Biochemistry
“Strategical” molecules for the prebiotic synthesis,
like HCN and OCN, are easily formed by fast ion impact.
main ion-solid mechanisms
2- Sputtering (neutrals and ions)
3- Chemical reactions
4- Structural modifications
(compaction)
MeV ion
ICE grain
COMETA
Final comments : dependence on S
From the sputtering and radiolysis experiments:
1- Ion beams interact with matter and transfer energy with
a characteristic rate called Stopping Power (S).
2- Three main phenomena :
dependence on S
Y ~ S2
a) Sputtering (removal of surface material):
σf or σd ~ Sn
b) Chemical reactions:
c) Compaction (structural modification):
Synthesis / sputtering:
2/3 < n < 3/2
σc ~ S2
σ/ Y ~ Sn / S2 = 1/S2-n
2- n > 0
Final comments : dependence on S
From the sputtering and radiolysis experiments:
1- Ion beams interact with matter and transfer energy with
a characteristic rate called Stopping Power (S).
2- Three main phenomena :
dependence on S
a) Sputtering (removal of surface material):
b) Chemical reactions:
c) Compaction (structural modification):
Y ~ S2
σf or σd ~ Sn
σc ~ S2
Conclusion:
Heavy ions are much more efficient than protons
for radiolysis AND sputtering
This is :
good – large molecules are formed faster by heavy ions
bad - they destroy the target before processing it enough
Final comments : dependence on m and T
σd
T
60 K
σf
σd
11 K
m
N2O radiolysis (only 2 elements)
σf
Final comments : dependence on m and T
σd
T
60 K
σf
σd
11 K
m
σf
as m increases
σd
low T
high T
σf / σd
σf
synthesis
very bad
bad
N2O radiolysis
Final comments : dependence on m and T
σd
T
60 K
σf
σd
11 K
m
σf
as m increases
σd
σf / σd
low T
high T
( If the N2O results can be generalized )
σf
synthesis
very bad
bad
CREDITS (lunar rocks & analogues)
CIMAP/GANIL (France): T. Langlinay, P. Boduch, H. Rothard
INAF Catania: G. Strazzulla, M.S. Palumbo
INAF Arcetri : J.R. Brucato
PUC-Rio: C. Ponciano,
J.M.S. Pereira,
G. C. Almeida
52
CREDITS (ions + ices)
PUC-Rio: C. Ponciano, V. Schmidt, C. Mejia, G. C. Almeida
CEFET-Rio: A.L.F. Barros, R. C. Pereira
ON: D. P. P. Andrade
IFRJ: E. Seperuelo Duarte
UNIVAP: S. Pilling
UFSC: L. Farenzena
Nitriles:
UFRJ: M.L. Rocco,
H.M. Boechat-Roberty,
F. Ribeiro
Darmstadt Univ. : Karl Wien
GANIL (France): P. Boduch, H. Rothard, A. Domaracka
53
Thank you for the attention !
Thanks for the attention !
Acknowledgments ($):
FAPERJ, CAPES / COFECUB, CNPq (INEspaço)
55
56
ISWA – 3-8 July 2016
Mass Spectrometry in Astrophysics
SUMMARY
MS has been used to analyze ions coming from the outer
space and arriving in Earth, Moon and in orbiting spacecrafts
→ Meteorites, lunar rocks, Mars surface, etc are extensively
examined by standard MS techniques
Isotope ratios and isotope dating (e.g. 238U - 206Pb or 14C) give
very useful information on the sample origin
→ Cosmic analogue samples have been produced in
laboratory and analyzed by MS
Such experiments show in particular what to expect from
in situ measurements
Campinas - 2013
Enio F. da Silveira - Van de Graaff Lab.
57
a) What Cosmic Rays are ?
• Primary Cosmic Rays are very energetic (103 to 1022 eV) charged
particles that traverse outer space
•
Basically, they are:
- light ions: protons + deuterons (87%) and α particles (11%)
- heavy 4n ions : 12C, 16O, 20Ne, 24Mg, 28Si, 32S, 40Ar, 40Ca and 56Fe (Ni)
- electrons (~1%)
[ unstable ions or neutrals are excluded: neutrons, neutrinos, X-rays, γ rays ]
•
After collision with interstellar matter and atmosphere,
Secondary Cosmic Rays are formed. They are constituted by:
- Li, Be, B, neutrons (formed by spallation)
- pions, kaons, mesons, positrons and γ rays
Solar Neutrinos in Earth : 6 x 1010 / cm2 s
14C
is a produced nuclide
58
What for?
Astronomy:
This means that iron beam
not protons
or alphas)
• To predict mean-lives(and
of molecules
in space
is responsible for chemistry
CR energy distribution
in ISM !
No life without SN ?
10 Ga →
CR
φ σd
Fe
H
Methanol
A&A (2011)
Genesis of the Fe-Ni meteorites (6%)
Abundance (log scale)
bendengó
Ni
Atomic number (Z)
Fe and Ni are abundant in planet cores
60
PDMS Analysis of Meteorites
Positive
ions 0,02
Isna
524
553
496
Counts (a. u.)
0,01
510
538
566
0,00
0,02
490 500 510 520 530 540 550 560 570 580
312
326
340
0,01
Negative
ions
354
369 382
0,00
300 310 320 330 340 350 360 370 380 390 400
m/q
62