Experimental cross sections Experimental cross sections
for electronfor electron--impact ionization impact ionization
and and
l tl t i bi tii bi tielectronelectron--ion recombination ion recombination
Alfred MüllerAlfred MüllerInstitut für AtomInstitut für Atom-- und Molekülphysikund Molekülphysik
JUSTUS-LIEBIG-ÄI M PA UNIVERSITÄT
GIESSENI M PA
Research Coordination Meeting, IAEA CRP, Vienna, March 04-06, 2009
Experimental Experimental workwork withinwithin thethe CRP CRP was was performedperformed bybypp yy
Dietrich Bernhardt A. Wolf, Sebastian Böhm (now industry)Alexander Borovik jr.
M. Grieser, J. Hoffmann, A. S. Jaroshevich, C. Krantz, D. A. Orlov, R. Repnow, F. Sprengerj
Carsten Brandau (now GSI)Mohammad Gharaibeh
p , p g
MPI-K, Heidelberg
(visting from Irbid, Jordan)Pierre-Michel HillenbrandJoachim Rausch
D. W. Savin,M Lestinsky D Lukić M SchnellJoachim Rausch
Jan RudolphStefan SchippersEike Schmidt
M. Lestinsky, D. Lukić, M. Schnell
Columbia University, A t & A t h iEike Schmidt
A.M.
Astronomy & Astrophysics, New York
IAMP, Giessen
OutlineOutline
1. Overview of tasks to be performedp
2. Crossed-beams technique Ionization of Li+ ions: test of theory and experiment
3 Results on electron-impact ionization of ions3. Results on electron-impact ionization of ions Xeq+ , q = 1,…,22, + preliminary 23,24,25
4 M d b bi i4. Merged-beam recombination
5 Results on electron-ion recombination5. Results on electron-ion recombinationSi3+, Feq+, q = 7,…, 10, 13,…, 22
1. Overview of tasks to be performed1. Overview of tasks to be performedpp
GiessenGiessen workwork plannedplanned forfor thethe presentpresent CRPCRP
cross sections for electron-impact single and multiple ionization of ions
i llespeciallyXeq+ ions q=1,2,…,15and possibly also for Snq+ ions q=1 2and possibly also for Snq ions q 1,2,…
rate coefficients for radiative and dielectronic recombination
f iof ions especially Fe8+, Fe13+, Fe14+, Fe16+Fe , Fe , Fe , Fe
2. Crossed-beams techniqueIonization of Li+ ions: test of theory and experiment
ElectronElectron--ionioncrossedcrossed beamsbeamscrossedcrossed--beamsbeamssetupsetup atat IAMPIAMP
Versatile apparatus for studying atomicfor studying atomic collisions
ElectronElectron--ionion beam beam crossingcrossing regionregion
Measurement Measurement ofof absolute absolute crosscross sectionssections
Requirement for the measurement of cross sections:
Beam density distributions → beam overlap → formfactor
ElectronElectron--ionion beam beam crossingcrossing regionregion
Measurement Measurement ofof crosscross sectionssectionsabsolute high precisionabsolute high precision
Test Test experimentexperiment withwith LiLi++ (1s(1s22) ) ionsions A Borovik et al J Phys B 42 (2009) 025203
5
6Li+(1s2) present absolute
normalized scanpresent CCC
A. Borovik et al., J. Phys. B 42 (2009) 025203
4
5
18 c
m2 ) present CCC
Pindzola et al. 2000
3
4
on (
10-1
1
22
s se
ctio
0
1
1Cro
ss
70 80 90 100 110
200 400 600 800 10000
Electron energy ( eV )
Theory and experiment are in good agreement for this 2-electron system
EffectEffect ofof metastablemetastable LiLi++ (1s2s (1s2s 33S) S) admixtureadmixture in in thetheionion beam onbeam on measuredmeasured ionizationionization crosscross sectionssectionsionion beam on beam on measuredmeasured ionizationionization crosscross sectionssections
A. Borovik et al., J. Phys. B 42 (2009) 025203
8
18 c
m2 )
6
s 3 S
on (
10-
4 1s2s
ss s
ectio
2 present experiment absolute present overview scan present threshold scanen
t cro
s
1 S
0
present threshold scan present CCC 13% m.s. + 87 % g.s. Berengut et al. RMPS 13% m.s.A
ppar
e
1s2
100 1000
Electron energy ( eV )
3. Results on electron-impact ionization of ionsXeq+ , q = 1,…,22, + preliminary 23,24,25, q , , , p y , ,
Xenon ions produced by ECR sourceXenon ions produced by ECR source 2003+++2++
50H2O
+OH+O+N2+C+
20 132131
129
40Xe8+
Xe7+
Xe6+
A)
10
15
136134
131
130+
CH+
30Xe9+
ent (
nA
1.92 1.93 1.94 1.95 1.96 1.97 1.98 1.990
5
136
128
20Xe10+
n C
urre
10 Xe12+
Xe11+ Io
0Xe14+ Xe13+
Xe
1.6 1.8 2.0 2.2 2.4 2.60
Analyzer Magnetic Field (kG)
ElectronElectron impactimpact singlesingle ionizationionization ofof XeXe+ + ionsions
3
Man et al (1987)
Single ionization of Xe+ (experimental data)
Man et al. (1987) Bell et al. (1993) Borovik et al. (2007)Borovik et al. (2007)m
2 )
2
Borovik et al. (2007) energy scan
( 10-1
6 cm
ctio
n (
1
Cro
ss s
e
Borovik et al unpublished data
0
C Borovik et al. unpublished data
100 10000
Electron energy ( eV )
ElectronElectron impactimpact double double ionizationionization ofof XeXe+ + ionsions
[Kr]4d105s25p5 energy scan data
Xe+ + e → Xe3+ + 3e
40
50 [Kr]4d 5s 5p energy scan data absolute data
2 )
30
40
10-1
8 cm
20
30
ctio
n (
1
10
20
oss
sec
4d giant resonance
0
10
Cro
Borovik et al. unpublished data
100 1000
Electron energy ( eV )
ElectronElectron impactimpact multiple multiple ionizationionization ofof XeXe+ + ionsions Borovik et al unpublished data
100
Borovik et al. unpublished data
10m2 )
σ
1( 10-1
8 c σ1,2
0.1
σ1,3
sect
ion
0.01
σ1,4
Cro
ss
0.001σ1,6 σ1,8σ1,7
σ1,5[Kr]4d105s25p5
100 1000
,,
Electron energy ( eV )
ElectronElectron impactimpact singlesingle ionizationionization ofof XeXe2+ 2+ ionsions2+ 3+
180
200 energy scan data
b l d[Kr]4d105s25p4
Xe2+ + e → Xe3+ + 2e
140
160
180 absolute data
m2 ) Borovik et al.
100
120
140
x10-1
8 cm
ground stateionization threshold
unpublished data
80
100
ctio
n ( x
40
60
ross
sec
0
20C
4d giant resonance
10 100 1000
Electron energy ( eV )
ElectronElectron impactimpact ionizationionization ofof XeXe3+ 3+ ionsions
140 [Kr]4d105s25p3
Xe3+ + e → Xe4+ + 2e
energy scan data
120
140 [ ] d 5s 5p energy scan data absolute data
2 ) Borovik et al
80
100
10-1
8 cm
2 Borovik et al. unpublished data
60
80
ctio
n (
1
40
ross
sec
0
20Cr
4d giant resonance
100 1000
Electron energy ( eV )
IonizationIonization ofof XeXe7+ 7+ ionsions byby electronselectrons andand photonsphotons
30
4d – nldipole
allowed
( Mb
) 20
7+ 8+
electron-impactexcitation-autoionization
allowed
ectio
n
0
10 e + Xe7+ → Xe8+ + 2e
Borovik et al. unpublished data1000
cros
s se 0
γ + Xe7+ → Xe8+ + e 4d – 5f
500
zatio
n c γ e → e e
photo-excitationautoionization Schippers et al., ICPEAC 2009
Abstract submitted
90 100 110 120 130 140 150 160 170 180
0Ioni Abstract submitted
90 100 110 120 130 140 150 160 170 180
Energy ( eV )
Single ionization of XeSingle ionization of Xeq+q+ ions: overviewions: overviewA B ik j M Gh ib h S S hi d A Müll 2007
Xe1+
Xe2+
A. Borovik jr., M. Gharaibeh, S. Schippers, and A. Müller, 2007
100 Xe3+
Xe4+
Xe5+b )
10
Xe Xe6+
Xe7+
X 8+on (
M
10 Xe8+
Xe9+
Xe10+
s se
ctio
1
Xe11+
Xe12+
Xe13+
Cro
ss
100 1000
Xe Xe14+
Xe15+unpublished data
100 1000
Electron energy ( eV )
Xenon ions produced by ECR sourceXenon ions produced by ECR source 2007
25
O2+
2014+
C2+
O
15t ( n
A)
Xe16+
Xe15+ Xe14+
Xe13+
Xe17+
10
n C
urre
nt
Xe18+
19
N2+
5
Ion
Xe19+
Xe20+
0Xe22+
Xe
Xe21+
1350 1400 1450 1500 1550 1600 1650 1700 17500
Magnetic Field ( G )
ElectronElectron impactimpact ionizationionization ofof XeXeqq+ + ionsions, q=1,…,22, q=1,…,22Borovik et al. unpublished data
100
10 q =8 cm
2 ) 5
10
20
15
q 1 2 3 4on
( x1
0-1
1 5 6 7 8
9ss s
ectio
0.1
9 10 11 12
13
Cro
s
5
10
13 14 15 16 17
Charge
15
20
18 19 20 21
22
ge state
0 200 400 600 800 1000
22
Relative electron energy ( eV )
ElectronElectron impactimpact singlesingle ionizationionization ofof XeXe12+ 12+ ionsions
Borovik et al. unpublished data
Giessen experiment
Pi d lPindzola group DW direct + EA
ElectronElectron impactimpact singlesingle ionizationionization ofof XeXe22+ 22+ ionsions
B ik t l bli h d d t1.5Theory Mandelbaum et al.:
direct ionization)Borovik et al. unpublished data
Giessen experiment1 0
direct ionization 3d-nl EA 3p-nl EAsummed cross section-1
8 cm
2
1.0 summed cross sectionPresent experiment:
absolute datan (
10-
Pi d l0.5
energy scan
sect
io
Pindzola group DW direct + EA
Cro
ss
600 700 800 900 1000
0.0
600 700 800 900 1000
Electron-ion collision energy ( eV )
ElectronElectron impactimpact singlesingle ionizationionization ofof XeXe10+ 10+ ionsions
Single ionization of Xe10+
A Müller Group6 A. Müller Groupmostly unpublished data
4
cm-2 )
10→
11 (
c
2 energy scan 2003 absolute data 2003 A=132 absolute data 2003 A=129 absolute measurement 2007absolute measurement 1992
σ
0
absolute measurement 1992 G. Hofmann et al., HCI VI, AIP Conf. Proc. 274 (1992) 485
100 1000
Electron-ion collision energy ( eV )
ElectronElectron impactimpact ionizationionization ofof XeXe24+ 24+ ionsions
X 24+ X 25+ 2
[Ar]3d104s2
Xe24+ + e → Xe25+ + 2e
1.4
cm2 )
g.s. ionization
( 10-1
8 c threshold
1.2
ectio
n
Borovik et al. preliminary
1.0
Cro
ss s
e
Strong resonance contributions
p yunpublished data
C
Unknown background (high Rydberg states?)
850 900 950 1000
Electron energy ( eV )
4. Merged-beam recombination
ElectronElectron--ion collisions at heavyion collisions at heavy--ion storage ringsion storage ringsd ll l
from acceleratordipolequadrupole
Schottky
molecularfragmentimaging
induction
chargedfragmentcounting
beam profilemonitor
(hor./vert.)ion currentmonitor
ypick-up accelerator
septuminjectionand
extraction
Electron target sectionrecombination
extractedbeam
ion beamdirection
electron coolercollision product
detectors5m
ionizationionizationrecombination
Technique of merged beamsTechnique of merged beams
exploit extended interaction length and kinematic advantages
electronbeam
icharge-state
lion
beam( )
analyzer
Aq+
A(q-1)+
Storage ring TSR Storage ring TSR atat MaxMax--PlanckPlanck--Institut für Institut für Kernphysik, Heidelberg, Kernphysik, Heidelberg, wherewhere metastablesmetastables die out !?die out !?p y , g,p y , g,
5. Results on electron-ion recombinationSi3+, Feq+, q = 7,…, 10, 13,…, 22, , q , , , , ,
Dielectronic Dielectronic recombinarecombina--i f Fi f F
Fe17+ Fe18+
tion of Fe Ltion of Fe L--shell ions: shell ions: a jointa jointa jointa jointUSUS--German German project for project for p jp jastrophysicsastrophysics Fe19+ Fe20+
Columbia-Astrophysics Laboratory
Fe22+Fe21+
y
Justus-Liebig-Universität Fe22FeGiessen
Max-Planck-fInstitut für
Kernphysik
DielectronicDielectronic recombinationrecombination ofof FeFe16+16+
Fe16+ (2p6 1S0) + e → Fe15+ (2p5 3d 1P1 nl) → Fe15+ (2p6 3s) + photons
Dipole excitation of the ion core, high resonance energies
E. W. Schmidt et al., Proceedings of the Tokyo HCI Conference (2008)Proceedings of the Tokyo HCI Conference (2008)
Rate Rate coefficientcoefficient ofof dielectronicdielectronic recombinationrecombination ofof FeFe16+16+
E W Schmidt et al Proceedings of the Tokyo HCI Conference (2008)E. W. Schmidt et al., Proceedings of the Tokyo HCI Conference (2008)theory and experiment in agreement
Radiative recombination
Zatsarinny 2004Gu 2003
Dielectronic recombination
DielectronicDielectronic recombinationrecombination ofof FeFe15+15+
J. Linkemann et al., Nucl. Instrum. Meth. B 98, 154 (1995)
30 TSR experiment autostructure theory d7
l'
/2 ∞
3 /s )
3/2
∞
20 3s →
3d
4l'
s →
3p 1/
0-10 c
m3
3s →
3p 3
3s →
4l 3
ent
( 10 3
10
coef
ficie
0
Rat
e c
0 10 20 30 400
Electron energy ( eV )
Rate Rate coefficientcoefficient ofof dielectronicdielectronic recombinationrecombination ofof FeFe15+15+
J Linkemann et al Nucl Instrum Meth B 98 154 (1994)J. Linkemann et al., Nucl. Instrum. Meth. B 98, 154 (1994)A. Müller, J. Mass. Spectrom. 192, 9 (1999)
RR Arnaud & Raymond DR Arnaud & Raymond experiment Linkemann et al.
RR
m3 /s
)
10-10
ent
( cm
11
DRexp
coef
fici
10-11
ma
rate
10-12
Plas
m
problem:low energy DR resonances
104 105 106 107 10810
Plasma temperature ( K )
RecombinationRecombination ofof FeFe7+ 7+ andand FeFe8+8+ ionsionsE W Schmidt et alE. W. Schmidt et al., A.& A. 492, 265 (2008)
Rate Rate coefficientscoefficients forfor recombinationrecombination ofof FeFe8+8+ ionsions
E. W. Schmidt et al., A.& A. 492, 265 (2008)
SummarySummary
Electron-impact ionization of ions:Cross sections for single and multiple ionization
of Xeq+ ions, q=1,…,22, ...,25and of Snq+ ions q=1 2 6and of Snq+ ions, q=1,2,…,6,…
are being measured in Giessen and analysis of the experimental results is underway. ((experimental results is underway. ((
Dielectronic recombination:resonance strengths and plasma rate coefficients are determined in high resolution storage ring experimentsdetermined in high-resolution storage ring experiments.Data for Fe7+ through Fe10+ and Fe13+ through Fe22+ have been obtained and most of them are published. Data onbeen obtained and most of them are published. Data on Si3+ have been published.