High resolution Auger projectile e- spectroscopy: A state-selective tool to study highly charged ion - atom collisions Theo J.M.
Download ReportTranscript High resolution Auger projectile e- spectroscopy: A state-selective tool to study highly charged ion - atom collisions Theo J.M.
Slide 1
High resolution Auger projectile e- spectroscopy:
A state-selective tool to study
highly charged ion - atom collisions
Theo J.M. Zouros
Department of Physics
University of Crete - Heraklion
LIBRA kick-off meeting
Demokritos March 11, 2009
1
Slide 2
Ion – Atom/electron Collisions
∆t = 10-17 s
Interaction
t = -∞
Preparation
Atom/Molecule Target
q = 0 (neutral)
Gas/Solid
gs or excited state
n ~ 1012-1020 #/cm3
e-
Ionization
Excitation
Transfer
combinations
t = -∞
Relaxation
Non radiative: Auger electrons
Radiative: Photon decay
e- beam Target
q = -1
I ~ 1-50 μA
n ~ 106-108 #/cm3
Ion beam
Z ~ 1-12
I ~ 1-100 nA
q ~ 1-12
E ~ 0.5-2 MeV/u
V ~ 3-6 a.u.
gs or metastable
e-
Black box?!
e-
γ
γ
Detectors
projectile, recoil,
photon, electron
coincidences
ΔΩ – solid angle
ε - efficiency
Slide 3
UoC HEMISPHERICAL ANALYZER
WITH 2-D PSD 0o ELECTRON SPECTROMETER
Faraday Cup
Ion Beam
4-element lens
Inner
hemisphere
Gas Cell
Pressure Gauge
Gas in
θ
Ion
electrons
PSD
X-Position
Y- Position
Timing
e00 dgrs
Outer
hemisphere
Resolution ~ 0.1%
ΔΩ = 1.8 x 10-4 sr
Slide 4
Experimental Setup at the 7MV tandem of
J R Macdonald Laboratory – Kansas State university
1997
Dedicated experimental
setup 1990 – 2007
Now have moved all to
Demokritos Tandem
2003
Slide 5
-18
cusp ve = Vp
10
Binary Encounter
(ve = 2Vp)
2s
-22
10
0
2
2p
2s
inelastic
scattering
3lnl'(n>3)
0
0
2s
-21
10
3l3l'
3l3l'
2
DDCS (cm /eV sr)
-20
10
0
0 electron spectra
1s
-19
10
8+
30.04 MeV F + H2
0
180
elastic
scattering
0
180
1000
2000
LAB
Electron
(eV)
Demokritos
13,Energy
2003
3000
4000
5
Slide 6
High resolution ion Auger electron spectra
E.P. Benis – PhD thesis, UoC 2001
Slide 7
Elastic Scattering of Quasi-free Electrons on B4+ Ions
1
2l3l'
21
2p S
3
2s2p P
21
3
2p D
21
2s S
4
2s2p P
5
2
2l4l'
2
1
2l5l'
1
2
-20
2
d /dd (10 cm /eV sr)
4+
3.91 MeV B + H2
2l2l'
d 2σ
dσ
3J(vz )
(Ee )
free Vp vz
ddEe quasifree dΩ
2lnl' Series Limit
Doubly Excited states
6
0
180
190
200
210
220
230
240
250
0
260
230
240
250
260
Zouros, Benis, Gorczyca,
010701(R) (2003)
ElectronPRA68,
Energy (eV)
-
4+
10
2
d/d (10 cm /sr)
e + B
-18
R - Matrix
1
180
190
200
210
220
Electron Energy (eV)
Slide 8
Elastic Scattering of Quasi-free Electrons on B3+ Ions
Doubly Excited states
15
3+
22
1s2p S
7
6
----- 2s2p 1P
22
1
2
1s(2s2p P) P
3
2
1s(2s2p P) P
4
22
-20
6
1s2s2p P
9
1s2lnl' (n>2)
5
4
3
2
3
1
2
d /dd (10
1s2p D
12
1s2s S
2
cm /eV sr)
1s2l2l'
----- 2s2p 3P
4.0 MeV B + H2
0
150
160
165
170
175
180
185
190
195
200
0
205
190
195
200
205
Zouros, Benis, Gorczyca, PRA68, 010701(R) (2003)
Electron- Energy
(eV)
3+
e + B
-18
2
d/d (10 cm /sr)
100
155
R - Matrix
10
1
0.1
150
155
160
165
170
175
180
185
Electron Energy (eV)
Slide 9
Ion-atom/electron interactions:
Investigation of the Coulomb force
• Force is Coulomb:
Potential usually known - can write down a Hamiltonian
• Calculate emission or interaction cross sections
• Difficulties: many particles, long range force, correlation effects
• Model calculations
• Develop theoretical and experimental techniques
• Test approximations
Slide 10
Interest in ion-electron/atom collisions
Applications
• Tokomak and Astrophysical Plasmas
• Accelerator technology - Storage rings
• Radiation damage – cancer therapy
• Basic atomic collisions
• Use HCI and simple targets – few-electron systems
• Study ion excitation rather than target excitation:
Control charge state q of ion – N number of electrons
Isoelectronic sequence study – same N different Z
In preparation for PHYSICS REPORTS
Zero-degree Auger spectroscopy of Projectile Ions in atomic collisions
in collaboration with N. Stolterfoht (HMI-Berlin)
Slide 11
Dept. of Physics, University of Crete-Heraklion, Crete
Theo J.M. Zouros (Θεόδωρος Τζούρος - [email protected])
Project: Investigation of one- and two-electron processes in energetic ion-atom
collisions using high resolution Auger projectile electron spectroscopy
Goal: State-selective cross section measurements of basic atomic collision processes and the investigation of their
collisional energy dependence. Processes include capture, excitation, ionization and combinations such as transferexcitation, transfer-loss, double-electron capture etc. Investigation of dynamic electron correlation effects.
Scientific domain: Atomic collision physics (Basic Research)
Beams: p, Li, B, Be, C, N, O, F and possibly higher Z
Charge-states: bare, one-, two-, three- and four electron ions, i.e. F6-9+ etc.
Intensities: 10 nA
Setup: installed at INP permanently, modifications necessary.
Spectrometer: Electrostatic energy analyzer in magnetically shielded chamber.
Detectors: MCP or channeltron
Targets: differential pumped gas target using H2, He, Ne, Ar etc.
Personnel: 1 Senior scientist, ideally 1 post-doc and or 1 or 2 students
Man-power support by INP (Yes/No – No. of scientists – Mech. Workshop etc.) :
Other details: Will need basic NIM electronic support, 3-4 3-5kV power supplies, 2-3 turbo pumps and data acquisition
and control programs – possibility of collision chamber and spectrometer exists
Is the project part of an international collaboration ? : Yes (Kansas State U., ATOMKI, ITS-LEIF EU network)
Is the project a preparatory work for expmts. abroad ? : Not necessarily but could be
1st TANDEM users meeting, Feb. 3, 2006, INP/Demokritos, Athens
Slide 12
Thank the LIBRA organizers
and the DEMOKRITOS tandem staff for their help so far
And in the future to come
Looking forward to a mutually profitable
collaboration/use of the facility
Will need help setting up and running experiments
all interested parties (particularly students)
are invited to join
[email protected]
High resolution Auger projectile e- spectroscopy:
A state-selective tool to study
highly charged ion - atom collisions
Theo J.M. Zouros
Department of Physics
University of Crete - Heraklion
LIBRA kick-off meeting
Demokritos March 11, 2009
1
Slide 2
Ion – Atom/electron Collisions
∆t = 10-17 s
Interaction
t = -∞
Preparation
Atom/Molecule Target
q = 0 (neutral)
Gas/Solid
gs or excited state
n ~ 1012-1020 #/cm3
e-
Ionization
Excitation
Transfer
combinations
t = -∞
Relaxation
Non radiative: Auger electrons
Radiative: Photon decay
e- beam Target
q = -1
I ~ 1-50 μA
n ~ 106-108 #/cm3
Ion beam
Z ~ 1-12
I ~ 1-100 nA
q ~ 1-12
E ~ 0.5-2 MeV/u
V ~ 3-6 a.u.
gs or metastable
e-
Black box?!
e-
γ
γ
Detectors
projectile, recoil,
photon, electron
coincidences
ΔΩ – solid angle
ε - efficiency
Slide 3
UoC HEMISPHERICAL ANALYZER
WITH 2-D PSD 0o ELECTRON SPECTROMETER
Faraday Cup
Ion Beam
4-element lens
Inner
hemisphere
Gas Cell
Pressure Gauge
Gas in
θ
Ion
electrons
PSD
X-Position
Y- Position
Timing
e00 dgrs
Outer
hemisphere
Resolution ~ 0.1%
ΔΩ = 1.8 x 10-4 sr
Slide 4
Experimental Setup at the 7MV tandem of
J R Macdonald Laboratory – Kansas State university
1997
Dedicated experimental
setup 1990 – 2007
Now have moved all to
Demokritos Tandem
2003
Slide 5
-18
cusp ve = Vp
10
Binary Encounter
(ve = 2Vp)
2s
-22
10
0
2
2p
2s
inelastic
scattering
3lnl'(n>3)
0
0
2s
-21
10
3l3l'
3l3l'
2
DDCS (cm /eV sr)
-20
10
0
0 electron spectra
1s
-19
10
8+
30.04 MeV F + H2
0
180
elastic
scattering
0
180
1000
2000
LAB
Electron
(eV)
Demokritos
13,Energy
2003
3000
4000
5
Slide 6
High resolution ion Auger electron spectra
E.P. Benis – PhD thesis, UoC 2001
Slide 7
Elastic Scattering of Quasi-free Electrons on B4+ Ions
1
2l3l'
21
2p S
3
2s2p P
21
3
2p D
21
2s S
4
2s2p P
5
2
2l4l'
2
1
2l5l'
1
2
-20
2
d /dd (10 cm /eV sr)
4+
3.91 MeV B + H2
2l2l'
d 2σ
dσ
3J(vz )
(Ee )
free Vp vz
ddEe quasifree dΩ
2lnl' Series Limit
Doubly Excited states
6
0
180
190
200
210
220
230
240
250
0
260
230
240
250
260
Zouros, Benis, Gorczyca,
010701(R) (2003)
ElectronPRA68,
Energy (eV)
-
4+
10
2
d/d (10 cm /sr)
e + B
-18
R - Matrix
1
180
190
200
210
220
Electron Energy (eV)
Slide 8
Elastic Scattering of Quasi-free Electrons on B3+ Ions
Doubly Excited states
15
3+
22
1s2p S
7
6
----- 2s2p 1P
22
1
2
1s(2s2p P) P
3
2
1s(2s2p P) P
4
22
-20
6
1s2s2p P
9
1s2lnl' (n>2)
5
4
3
2
3
1
2
d /dd (10
1s2p D
12
1s2s S
2
cm /eV sr)
1s2l2l'
----- 2s2p 3P
4.0 MeV B + H2
0
150
160
165
170
175
180
185
190
195
200
0
205
190
195
200
205
Zouros, Benis, Gorczyca, PRA68, 010701(R) (2003)
Electron- Energy
(eV)
3+
e + B
-18
2
d/d (10 cm /sr)
100
155
R - Matrix
10
1
0.1
150
155
160
165
170
175
180
185
Electron Energy (eV)
Slide 9
Ion-atom/electron interactions:
Investigation of the Coulomb force
• Force is Coulomb:
Potential usually known - can write down a Hamiltonian
• Calculate emission or interaction cross sections
• Difficulties: many particles, long range force, correlation effects
• Model calculations
• Develop theoretical and experimental techniques
• Test approximations
Slide 10
Interest in ion-electron/atom collisions
Applications
• Tokomak and Astrophysical Plasmas
• Accelerator technology - Storage rings
• Radiation damage – cancer therapy
• Basic atomic collisions
• Use HCI and simple targets – few-electron systems
• Study ion excitation rather than target excitation:
Control charge state q of ion – N number of electrons
Isoelectronic sequence study – same N different Z
In preparation for PHYSICS REPORTS
Zero-degree Auger spectroscopy of Projectile Ions in atomic collisions
in collaboration with N. Stolterfoht (HMI-Berlin)
Slide 11
Dept. of Physics, University of Crete-Heraklion, Crete
Theo J.M. Zouros (Θεόδωρος Τζούρος - [email protected])
Project: Investigation of one- and two-electron processes in energetic ion-atom
collisions using high resolution Auger projectile electron spectroscopy
Goal: State-selective cross section measurements of basic atomic collision processes and the investigation of their
collisional energy dependence. Processes include capture, excitation, ionization and combinations such as transferexcitation, transfer-loss, double-electron capture etc. Investigation of dynamic electron correlation effects.
Scientific domain: Atomic collision physics (Basic Research)
Beams: p, Li, B, Be, C, N, O, F and possibly higher Z
Charge-states: bare, one-, two-, three- and four electron ions, i.e. F6-9+ etc.
Intensities: 10 nA
Setup: installed at INP permanently, modifications necessary.
Spectrometer: Electrostatic energy analyzer in magnetically shielded chamber.
Detectors: MCP or channeltron
Targets: differential pumped gas target using H2, He, Ne, Ar etc.
Personnel: 1 Senior scientist, ideally 1 post-doc and or 1 or 2 students
Man-power support by INP (Yes/No – No. of scientists – Mech. Workshop etc.) :
Other details: Will need basic NIM electronic support, 3-4 3-5kV power supplies, 2-3 turbo pumps and data acquisition
and control programs – possibility of collision chamber and spectrometer exists
Is the project part of an international collaboration ? : Yes (Kansas State U., ATOMKI, ITS-LEIF EU network)
Is the project a preparatory work for expmts. abroad ? : Not necessarily but could be
1st TANDEM users meeting, Feb. 3, 2006, INP/Demokritos, Athens
Slide 12
Thank the LIBRA organizers
and the DEMOKRITOS tandem staff for their help so far
And in the future to come
Looking forward to a mutually profitable
collaboration/use of the facility
Will need help setting up and running experiments
all interested parties (particularly students)
are invited to join
[email protected]