Exploratory studies towards experimental Exploratory studies towards experimental data for electron data for electron-impact ionization impact ionization Exploratory studies towards experimental Exploratory studies towards experimental data for electron data for electron-impact ionization impact ionization data for electron data for electron-impact ionization, impact ionization, electron electron-ion recombination and ion recombination and hti i ti ft t i hti i ti ft t i data for electron data for electron-impact ionization, impact ionization, electron electron-ion recombination and ion recombination and hti i ti ft t i hti i ti ft t i photoionization of tungsten ions photoionization of tungsten ions photoionization of tungsten ions photoionization of tungsten ions Alfred Müller Alfred Müller Institut für Atom Institut für Atom- und Molekülphysik und Molekülphysik JUSTUS-LIEBIG- Ä I MP A UNIVERSITÄT GIESSEN I M P A First Technical Meeting on Spectroscopic and Collisional Data for W from 1 eV to 20 keV IAEA, Vienna, December 13 – 15, 2010
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IMPA I M P JUSTUS-LIEBIG- UNIVERSIT ÄÄT GIESSEN · 12/13/2010 · photoionization of tungsten ions Alfred Müller Institut für AtomInstitut für Atom-- und Molekülphysikund Molekülphysik
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Exploratory studies towards experimental Exploratory studies towards experimental data for electrondata for electron--impact ionizationimpact ionization
Exploratory studies towards experimental Exploratory studies towards experimental data for electrondata for electron--impact ionizationimpact ionizationdata for electrondata for electron--impact ionization, impact ionization,
electronelectron--ion recombination and ion recombination and h t i i ti f t t ih t i i ti f t t i
data for electrondata for electron--impact ionization, impact ionization, electronelectron--ion recombination and ion recombination and h t i i ti f t t ih t i i ti f t t iphotoionization of tungsten ionsphotoionization of tungsten ionsphotoionization of tungsten ionsphotoionization of tungsten ions
Alfred MüllerAlfred MüllerInstitut für AtomInstitut für Atom-- und Molekülphysikund Molekülphysik
JUSTUS-LIEBIG-ÄI M PA UNIVERSITÄT
GIESSENI M PA
First Technical Meeting on Spectroscopic and Collisional Data for W from 1 eV to 20 keV
IAEA, Vienna, December 13 – 15, 2010
Outline Outline Outline Outline
I. IntroductionI. Introduction
II. Electron-ion recombination
III. Photoionization of ions
IV. Electron impact ionization of ions
V. Outlook and plans
Outline Outline Outline Outline
I. IntroductionI. Introductionatomic data needs – atomic data situation
II. Electron-ion recombination
III Photoionization of ionsIII. Photoionization of ions
IV. Electron impact ionization of ionsIV. Electron impact ionization of ions
V. Outlook and plans
Evolution Evolution ofof tungstentungsten ionion chargecharge statesstates in a in a plasmaplasmaEvolution Evolution ofof tungstentungsten ionion chargecharge statesstates in a in a plasmaplasmaT Pütterich, R Neu, R Dux, A D Whiteford, M G O’Mullane and the ASDEX Upgrade TeamPlasma Phys. Control. Fusion 50 (2008) 085016
rate coefficients for ionization and recombination requiredqIonization: CADW calculations of Ludlow et al. (2005)Recombination: Burgess – Merts (1965 – 1976) with ad hoc modifications
tiontion of Fe Lof Fe L--shell ions: shell ions: tiontion of Fe Lof Fe L--shell ions: shell ions: a joint a joint USUS--German German a joint a joint USUS--German German project for project for astrophysicsastrophysicsproject for project for astrophysicsastrophysics Fe19+ Fe20+
Columbia-Astrophysics Laboratory
Fe22+Fe21+
Laboratory
Justus-Liebig-Universität Fe22FeGiessen
Max-Planck-Institut für Kernphysik
ConclusionsConclusions so so farfarConclusionsConclusions so so farfar
Merged-beam electron-ion recombination experiments deliver high-accuracy data
Atoms of all elements in any given charge stateare accessible at ion storage ringsare accessible at ion storage rings
State of the art theory provides goodpredictions for light few-electron ions
For complex ions the theory situation is notFor complex ions the theory situation is not satisfying; new theoretical approaches to recombination of many-electron ions have to b d l dbe developed
Only experiments can guide such developmentsOnly experiments can guide such developments
Outline Outline Outline Outline
I. IntroductionI. Introduction
II. Electron-ion recombination
III. Photoionization of ions
IV. Electron impact ionization of ions
V. Outlook and plans
Time‘sTime‘s arrowarrowTime‘sTime‘s arrowarrow
recombination
e-Aq+ [ A(q-1)+ ]**
A(q-1)+
photoionization
e- Aq+[ A(q-1)+ ]**
A(q-1)+ [ A(q-1)+ ]**
A(q-1)+ e-ee
Time Time reversalreversal symmetrysymmetry: : detaileddetailed balancebalanceTime Time reversalreversal symmetrysymmetry: : detaileddetailed balancebalance
IAMP in collaboration with R. A. Phaneuf et al., University of Nevada RenoUniversity of Nevada, Reno
Time Time reversalreversalofof CC3+3+ photophoto--Time Time reversalreversalofof CC3+3+ photophoto-- 0.10
CRYRING datatime reversed
C3+(1s [2s2p 3P] 2P0)dielectronic
DR data: Mannervik et al., PRA 55, 1819 (1997)
ppionizationionization
ppionizationionization
0.10 time reversed ALS data
dielectronic recombinationof C4+(1s2 1S)
( Mb
)
0.05
σ DR (
CRYRING
Two totally different independently absolute
299.5 300.0 300.50.00
E +64.492 eV
CRYRING
independently absolute measurements.
1000 ALS data
resolution 47 meV Voigt-fit
C3+(1s [2s2p 3P] 2P0)photo excitation
Ee 64.492 eV
ALS500
R-matrix calculation resolution 47 meV
Mb
)pof C3+(1s22s 2S)ALS
0
σ PI (
299.5 300.0 300.5Photon energy ( eV )
A. Müller, S. Schippers, R.A. Phaneuf et al.J. Phys. B 42 (2009) 235602
SummarySummary on on photoionizationphotoionization ofof ionsionsSummarySummary on on photoionizationphotoionization ofof ionsions
complements electron-ion recombination studiescomplements electron ion recombination studies employing detailed balance
hi h l ti iblvery high energy resolution possible
detailed spectroscopy of excited states of ions p pyaccessible
Outline Outline Outline Outline
I. IntroductionI. Introduction
II. Electron-ion recombination
III. Photoionization of ions
IV. Electron impact ionization of ions
V. Outlook and plans
ElectronElectron--ion crossedion crossed--beams setup at IAMPbeams setup at IAMPElectronElectron--ion crossedion crossed--beams setup at IAMPbeams setup at IAMPpppp
Versatile apparatus for studying atomicfor studying atomic collisions
ElectronElectron--ion crossedion crossed--beams setup at IAMPbeams setup at IAMPElectronElectron--ion crossedion crossed--beams setup at IAMPbeams setup at IAMP
El t i lli i ( V )Electron-ion collision energy ( eV )
Similar discrepancies found for other highly charged ions
ImportanceImportance ofof multiple multiple ionizationionizationImportanceImportance ofof multiple multiple ionizationionizationA B ik t l k i
Xe2+
A. Borovik et al., work in progress
10-16
single ionization)Xe
g
n ( c
m2
sect
ion
double ionization
10-17
Cro
ss double ionization
10-17
0 200 400 600 800 1000
Electron energy ( eV )
ConclusionConclusion on on electronelectron--impactimpact singlesingle ionizationionizationConclusionConclusion on on electronelectron--impactimpact singlesingle ionizationionization
Present state of the art theory can predictcross sections fordirect single ionization of few-electron ionswith high accuracy
Present state of the art theory has difficulties topredict single ionization of complex manypredict single ionization of complex many-electron ions where excitation-autoionizationprocesses prevailp p
There is no theory for multiple ionizationof complex ions
Summary so Summary so farfarSummary so Summary so farfar
Total cross sections for single ionization and for recombinationgas well as for photoionization of few-electron ions are quitewell understood; theoretical data of benchmark quality are (becoming) availablefor few-electron systems
Understanding of collisions and structure of complex ionsis not satisfyingy g
Experiments with complex many-electron systems are required to test and to guide theoretical approachesrequired to test and to guide theoretical approaches