Momentum Imaging in Atomic Collision Physics • BREADTH : MICROMODEL OF ICPEAC • WHAT IS IT? • FOCUS: DOUBLE IONIZATION ICPEAC 2003 ICPEAC 2003
Jan 13, 2016
Momentum Imaging in Atomic Collision Physics
• BREADTH : MICROMODEL OF ICPEAC
• WHAT IS IT?
• FOCUS: DOUBLE IONIZATION
ICPEAC 2003ICPEAC 2003
BREADTH: MODEL OF ICPEAC ?
ICPEAC 2003ICPEAC 2003
EVENT BY EVENT EVENT BY EVENT MOMENTUM IMAGING MOMENTUM IMAGING ION-ATOM COLLISIONSION-ATOM COLLISIONS
COLLISIONS IN MOTS COLLISIONS IN MOTS USE TO ANALYZE MOTUSE TO ANALYZE MOT
IONIZATION IONIZATION WITH INTENSE LASERWITH INTENSE LASER
PULSESPULSES
WITH SYNCHROTRONWITH SYNCHROTRONRADIATIONRADIATION
OF MOLECULES OF MOLECULES WHICH EXPLODEWHICH EXPLODE
Conceptual COLTRIMS
p
pp’
Projectile Electron Recoil
Single detectors
p
pB
E
Imaging
p
pp’
THE DETECTOR
The detectorThe detector
Well, not Well, not really, but really, but the idea is the idea is similarsimilar
CMS detector at FermilabCMS detector at Fermilab
Cold Target Recoil Ion Momentum SpectroscopyCold Target Recoil Ion Momentum Spectroscopy
EE
BB
COILSCOILS
POSITION AND POSITION AND TIME SENSITIVETIME SENSITIVEDETECTORSDETECTORS
P ALONG BEAM FROM TIMEP ALONG BEAM FROM TIMEP TRANSVERSE FROM POSITIONP TRANSVERSE FROM POSITION
REACTIONREACTION
THE BASIC DETECTOR
CHOOSE ONE OF EACH
EE
BB
COILSCOILS
POSITION AND POSITION AND TIME SENSITIVETIME SENSITIVEDETECTORSDETECTORS
LASER BEAMLASER BEAM
SYNCHROTRONSYNCHROTRONRADIATION RADIATION PHOTON BEAMPHOTON BEAM
ION BEAMION BEAM
(SUPERSONIC)(SUPERSONIC)JETJET
/4 /4
/4
/4
MOTMOT
BEAMBEAM TARGETTARGET
DETECTORDETECTOR
CLASSIC CONFIGURATION : IONS ON JETS
EE
BB
COILSCOILS
POSITION AND POSITION AND TIME SENSITIVETIME SENSITIVEDETECTORSDETECTORS
ION BEAMION BEAM
SUPERSONICSUPERSONICJETJET
VARIATION ONE: PHOTONS ON JETS
EE
BB
COILSCOILS
POSITION AND POSITION AND TIME SENSITIVETIME SENSITIVEDETECTORSDETECTORS
SUPERSONICSUPERSONICJETJETSYNCHROTRONSYNCHROTRON
RADIATION RADIATION PHOTON BEAMPHOTON BEAM
VARIATION TWO: LASERS ON JETS
EE
BB
COILSCOILS
POSITION AND POSITION AND TIME SENSITIVETIME SENSITIVEDETECTORSDETECTORS
SUPERSONICSUPERSONICJETJETLASER BEAMLASER BEAM
VARIATION THREE: ION BEAMS ON MOT
EE
BB
COILSCOILS
POSITION AND POSITION AND TIME SENSITIVETIME SENSITIVEDETECTORSDETECTORS
ION BEAMION BEAM
/4 /4
/4
/4
MOTMOT
VARIATION FOUR: LASER BEAMS ON MOT
EE
BB
COILSCOILS
POSITION AND POSITION AND TIME SENSITIVETIME SENSITIVEDETECTORSDETECTORS
/4 /4
/4
/4
MOTMOT
LASER BEAMLASER BEAM
Some typical momenta in the interaction
Momentum carried by photon:
E/c , c=137 in au. : 8 x 10 –3 a.u. for a 300 eV photon.
Momentum carried by a 10 eV electron ejected from atom:
0.86 a.u.
Momentum carried by 5 eV molecular C+ fragment:
90 a.u.
Momentum of thermal He atom at 300 K / Rb atom at 250 x 10 -6 K
4 a.u. .017 a.u.
Experimental resolution:
Recoils < 0.2 a.u. Electrons < 0.05 a.u.
The physicsLow energy collisions: Capture by highly charged ions
Ionization : continuum electrons
High energy collisions:
Small Z/v…photons
Fixed in space molecules: inner shells
Single electron processes
Two electron processes
Intense laser
Large Z/v
Large Z/v
Small Z/v…photons
Capture by highly charged ions
-500 0 5000.0
0.2
0.4
0.6 Over barrier to make..
H2
++
H2
+
Ele
ctric
Fie
ld (
a.u
.)
Time (a.u.)
Field from 25+ ion at v=.05 with b=7 a.u.
Electric field caused by a passing Xe 26+ ion
Q spectra for capture from He by Ar 16+ ions
0 10 20 30-4
-3
-2
-1
0
1
n=5n=6
n=8n=9
n=7
Ar 15+ + He
Ar 16+ + He
Ene
rgy
(a.u
.)
R (a.u.)
M.Abdallah, W.Wolff, H.E.Wolf, E.Y.Kamber,M.Stockli and C.L.Cocke, Phys.Rev.A 58, 2911(1998).
Q value versus Auger electron energy in double capture
G. Laurent , M. Tarisien , X. Flechard , et al., Nucl. Inst. Meth. (2003, to be published).
O 6+ on He at 138 keV
O 6+ + HeO 4+ (nl,n’l’) + He ++
O 5+ + e Auger
High resolution Q value spectra from capture by Ne 7+ from He at 0.35 a.u.
D.Fischer, B.Feuerstein, R.D.DuBois, R.Moshammer, J.R.Crespo-Lopez-Urrutia et al., J. Phys. B 35, 1369 (2002).
Momentum resolution 0.07 a.u.
pz of recoil
Q-value spectra from Ar 8+ on atomic hydrogen
Experiment:Erge Edgu-Fry, Ph.D.ThesisTheory: Lee and Lin, Close coupling AO
-10 0 10 20 30 40 500
100
200
300
400
500
600
700
800
fd ps
fd p s
n=8
n=7
n=6n=5Ar8++H, v=0.32 a.u.
cou
nts
Q(eV)
Relative populations (%)Experiment Theory
5s 8.1 8.55p 14.6 19.65dfg 29.8 43.4Sum 5 52.5 71.66s 3.3 13.26p 32.5 6.36dfg 10.4 8.9Sum 6 46.3 28.4
MOTRIMS Van der Poel
M. van der Poel, C. V. Nielsen, M.-A. Gearba, and N. Andersen, Phys. Rev. Lett. 87, 123201 (2001).
Frauhenhofer diffraction in capture from Na by Li+
M.Van der Poel Ph.D. thesisOrsted Institute, Univ. Copenhagen
~ 10 -6 rad
MOTRIMS results: O 6+ on Na capture
J.W. Turkstra, R. Hoekstra, S. Knoop, D. Meyer, R. Morgenstern, and R. E. Olson, Phys.Rev.Lett. 87, 123202 (2001).
Experiment
CTMC
KSU MOTRIMS Cs+
R. Brédy, H. Nguyen, H. A. Camp, X. Flechard and B. D. DePaola, J.R.Macdonald Laboratory, Kansas State Univ.
-2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5
0.0005
0.0010
6 keV Cs++Rb(5s),Rb(5p) Cs*+Rb+
5p-5d
5s-6p
5s-6s
5p-6p
5p-6s
2.000
3.295
5.429
8.944
14.74
24.28
40.00
65.90
108.6
178.9
294.7
485.6
800.0
Q value (eV)
Sca
tterin
g A
ngle
(ra
d)
-3 -2 -1 0 1 2 30
5
10
15
20
Q Value (eV)
TAC
Tim
e (
s)
5.000
6.776
9.183
12.44
16.86
22.85
30.97
41.97
56.88
77.09
104.5
141.6
191.9
260.0
-3 -2 -1 0 1 20
5000
10000
15000
X 10
Na(4d)Na(3d)
Na(4s)
Na(3p) Na(3p)Capture from Rb(5s)Capture from Rb(5p)
Na(3s)
Cou
nts
Q value (eV)
KSU MOTRIMS Na+
R. Brédy, H. Nguyen, H. A. Camp, X. Flechard and B. D. DePaola, J.R.Macdonald Laboratory, Kansas State Univ.
Na+ capturing from Rb(5s) and Rb(5p)
5s-3p 5p-3p
laser off
laser on
T. G. Lee, H. Nguyen, X. Flechard, B. D. DePaola, and C. D. Lin Phys. Rev. A 66, 042701 (2002)
The physicsLow energy collisions: Capture by highly charged ions
Ionization : continuum electrons
High energy collisions:
Small Z/v…photons
Fixed in space molecules: inner shells
Single electron processes
Two electron processes
Intense laser
Large Z/v
Large Z/v
Small Z/v…photons
Ionization: continuum electrons
Projectile
Recoil
In plane
5 keV
10 keV
15 keV
Doerner et al,Phys.Rev.Lett. 77,4520 (1997)
Continuum electrons for fixed scattering plane
p on He
Electron spectra for He+ on He
M.A.Abdallah et al., Phys.Rev.81, 3627 (1998).
He+
He+
e-0.5
0.0
0.5
0.0 0.5 1.0
-0.5
0.0
0.5
-0.5
0.0
0.5
v ey /v
p
-0.5
0.0
0.5
0.0 0.5 1.0
-0.5
0.0
0.5
vez
/vp
0
50
100
150
-1.0 -0.5 0.0 0.5 1.0
tr mom=
0-1.5 a.u.
10 keV/u He+ + He (v
p = 0.64 a.u.)
0
50
100
150
200
250 tr mom=
1.5-3 a.u.
0
50
100
150
200 tr mom=
3-5 a.u.
coun
ts
0
100
200
300 tr mom=
5-10 a.u.
-1.0 -0.5 0.0 0.5 1.00
50
100tr mom=
10-15 a.u.
vey
/vp
1 eV
Electron spectra for Transfer Ionization for He++ on He
A.F.Afaneh, R Doerner, L Schmidt, Th Weber, K E Stiebing, O Jagutzki and H Schmidt-Boecking, J. Phys. B 35 L229 (2002).
Cou
nts
Ve,
y /
Vp
Ve, z / Vp
Pt= 8-16a.u.
Pt= 4- 8a.u.
Pt= 2- 4a.u.
Pt < 2.0a.u.
0.0 0.5 1.0 1.5
(e)
-0.5
0.0
0.5 (a)
0.0 0.5 1.0 1.5
-0.5
0.0
0.5 (b)
-0.5
0.0
0.5 (c)
0.0 0.5 1.0 1.5
-0.5
0.0
0.5 (d)
(f)
(g)
0.0 0.5 1.0 1.5
(h)
0
100
0
200
0
300
0
200
The physicsLow energy collisions: Capture by highly charged ions
Ionization : continuum electrons
High energy collisions:
Small Z/v…photons
Fixed in space molecules: inner shells
Single electron processes
Two electron processes
Intense laser
Large Z/v
Large Z/v
Small Z/v…photons
Single electron processes
Electron ejection by charged particle: large q vs small q
Small q………. “optical limit”Large impact parameterProjectile delivers energy onlySets positive charge in Oscillation against negative charge
Large q exchange with one electronRest of atom is spectator(Rutherford and Marsden)
V~ e i q.r
Single photoionization recoils
80 eV Single Ionization of He
krecoil ion = -ke
h R. Doerner et al., Phys. Rev. Lett. 76, 2654 (1996).
Very low perturbation He single ionization:electron – recoil momentum balance
1 GeV/u U 92+on He
Moshammer et al.,Phys.Rev.Lett. 79, 3621 (1997).
Kinematically complete: electron spectra for experimentally controlled q
Photons
Charged particles
q “binary”“recoil”
He+e-q
M.Schulz, R.Moshammer, D.H.Madison, R.E.Olson et al., J.Phys.B 34, L305 (2001).
A.Dorn, R.Moshammer, C.D.Schroeter, et al., Phys.Rev.Lett.82,2496(1999).
100 MeV/u C 6+ q=.88 a.u.
3 keV electronsq=1.5 a.u.
M.Schulz et al., Nature 422, 48 (2003)
Is everything understood for single ionization in the low perturbation limit?
100 MeV/u C 6+ on He
Single ionization electron momentum distributions
Experiment
Calculation (Madison)
Conclusion: nuclear momentumtransfer not being treated correctly.
High perturbation He single ionization:electron-recoil momentum balance
3.6 Mev/ Se 28+ on He
Moshammer et al.,Phys.Rev.A 56,1351 (1997).
The physicsLow energy collisions: Capture by highly charged ions
Ionization : continuum electrons
High energy collisions:
Small Z/v…photons
Fixed in space molecules: inner shells
Single electron processes
Two electron processes
Intense laser
Large Z/v
Large Z/v
Small Z/v…photonsTwo electron processes
Two electron removal: how to do it?
TS2 TS1
L.H.Andersen, H.Knudsen, P.Hvelplund, et al., Phys.Rev.Lett. 57, 2147 (1986).
High perturbation He double ionization: electron pair –recoil momentum balance
A.N.Perumal, R.Moshammer,M.Schulz and J.Ullrich, J.Phys.B 35, 2133 (2002).
3.6 MeV/u Au 53+ on Heq
He++
ee
Double ionization:Electron pair ejection
Single ionization
3.6 Mev/ Se 28+on He Moshammer et al.,Phys.Rev.A 56, 1351 (1997).
The small perturbation case
TS1 collision Shakeoff
Small Z/v or photon
Electron distributions: photodouble ionization of He
k+ = k1+k2
k- =(k1-k2)/2
Jacobi
k1,k2
Lab
k1
k2
k+
k-
selections rules A=0 implies electrons in state
E1 selection rules plus ee repulsion;No back to back, no parallel emissionOpening angle around 120 degrees
J S Briggs and V Schmidt, J.Phys.B 33, R1 (2000).
1 eV
Photodouble ionization of He
Electron momenta
20 eV excess energy
k+ = k1+k2
k1, k2
k- = (k1-k2)/2
H. Braeuning, R. Doerner, C.L. Cocke, M.H. Prior et al., J. Phys. B30, L649 (1997).
Can we get out of the “collective motion” region into the “single particle motion” region?
A.Knapp, M.Walter, Th. Weber, A.L.Landers, et al., .Phys.B L521 (2002).
Photodouble ionization at 529 eV photon energy
A.Knapp, A.Kheifets, I.Bray, Th.Weber, A.L.Landers et al., Phys.Rev.Lett.89, 033004 (2002).
The “shaken off” electron
Experiment Theory (CCC:Kheifets)
Soft electrons are shaken off
Harder electrons are generated in ee collisions
2eV
30eV
fastslow
Photodouble ionization of H2: the relaxation of the dipole selection rule
Thorsten Weber ,Ph.D. thesis, Univ. Frankfurt (2003) and Th. Weber et al., in preparation (2003) .
Helium:Node on cone
H2: Node is There but relaxed
Node on cone where no dipole moment of systemalong polarization vector
Walter and Briggs, PRL
85, 1630 (2000).
Photodouble ionization at 529 eV photon energy
A.Knapp, A.Kheifets, I.Bray, Th.Weber, A.L.Landers et al., hys.Rev.Lett.89, 033004 (2002).
The “shaken off” electron
Experiment Theory (Kheifets)
Soft electrons are shaken off
Shaken electron distribution from transfer ionization
H. Schmidt-Böcking, V. Mergel, R. Dörner et al., Europhys. Lett., 62 , 477 (2003) .
300 keV protons on He: capture one, other leaves
Correlated “Shakeoff” Shi and Lin
T.Y.Shi and C.D.Lin, Phys.Rev.Lett. 89, 163202 (2002).
The probability for ionization The momentum of the shaken electron
High velocity TI: CRYRING
H.T. Schmidt, A. Fardi, R. Schuch, et al., Phys. Rev. Lett., 89, 163201-3 (2002) and Henning Schmidt, private comm. 2003
recoil pzfast protons on He , capture one, make He++
Charged particle “dipole” double ionization
Photons
k+ =k1+k2
k- =(k1-k2)/2
Jacobi
k1,k2
Lab
Charged particles
q “binary”“recoil”
“recoil” “binary”
qHe++
ee
Electron distributions: double ionization of He DATA
“recoil”
“binary”
CCC Kheifets
Photodouble ionization
Experiment
A. Dorn, A.Kheifets, C.D.Schroeter, B.Jajjari et al., Phys.Rev.Lett.86, 3755(2001
q=0.6a.u.
2 keV electrons
q
1
2
1
2
The physicsLow energy collisions: Capture by highly charged ions
Ionization : continuum electrons
High energy collisions:
Small Z/v…photons
Fixed in space molecules: inner shells
Single electron processes
Two electron processes
Intense laser
Large Z/v
Large Z/v
Small Z/v…photons
Fixed in space molecules:Inner shells
Illuminating molecules from within
hhvv + CO + CO CO CO++ (1s (1s-1-1) + e) + e--(photoelectron) (few eV)(photoelectron) (few eV) (10 (10 –17–17 s) s) CO CO 2+2+ + e + e--(Auger) (high energy)(Auger) (high energy) (10 (10 –14–14 s) s)
CC++ + O + O + + (10 (10 –13–13 s) s)
University Frankfurt: Reinhard Dörner,Horst Schmidt-Böcking,Thorsten Weber,Alexandra Knapp, Till Jahnke, Lothar, Schmidt, Sven Schössler, Harald Bräuning, Achim Czasch
Kansas State University C. Lewis Cocke, Timur Osipov, Ali
Alnaser
LBNL Michael H. Prior, Jürgen Rösch, Andre Staudte
Western Michigan U. Allen Landers
Guest: Amine Cassimi (Ganil/Ciril)
What determines the angular distribution of the photoelectrons?
Polarization of incident Radiation : p-wave Direction of incident radiation:(Non-dipole effects?)
Depends on molecular orientation
Interference of wave Scattered on other center
e iq.r
Shape resonance inpotential well of molecule
Depends on external radiation
The sigma (f-wave) resonance in CO
is the photoelectron momentum vectoras you scan the photon energy
A.Landers, in “Photonic, Electronic and Atomic Collisions”,
ed. J.Burdoerger et al., p. 149 (Rinton, Princeton, 2002).
Steps of process and energeticsC2H2
+
CC22HH22
CC22HH22++++
h= 309 eV
Photoelectron
AugerAuger
D.Duflot et al., D.Duflot et al., J.Chem.Phys.10J.Chem.Phys.102,1(1995).2,1(1995).
KER spectrumKER spectrumT.Osipov,KSUT.Osipov,KSU
10 20 10 20
KER Vinylidenechannel
Auger electron angular distributions in CO
Th. Weber, M.Wedkenbrock, M.Balser, L.Schmidt, O.Jagutzki et al., Phys.Rev.Lett. 90, 153003 (2003).
Molecule does NOT remember how the hole was made
But for some channels the distribution is very sharp, even Headlight-like!
Is there an f-wave resonance in C2H2?
B.Kempgens et al., PRL 79, 35 (1997).
The f-wave enhancement in C2H4
Osipov, KSU, 2003
Comparison of C2H2 and C2H4
Recoil momentum spectra of near symmetric breakup for mass 24 or 26
Acetylene/Vinylidene
Can the angular distributions tell about the fragmentation dynamics?
EXPTTh.Weber et al., JPB 34, 3669 (2001).
THEORYR.Diez Muino, D.Rolles, F.J.Garcia de Abajo, F.Starrost, W.Schattke, C.S.Fadley and M.A.Van Hove, J.Electron Spec.Relat.Phenom.99,114(2001).
Use fragments to align molecule, look at Use fragments to align molecule, look at photoelectron distributionsphotoelectron distributions
PhotoemissionC2H2
+
10-17 sec
Slow?Slow?Fast?Fast?
CH2+ C+ CH+ CH+
AugerC2H2
++
10-14 sec
Lose molecule-photoelectron angleLose molecule-photoelectron angle Keep molecule-photoelectron angleKeep molecule-photoelectron angle
Use photoelectrons to align molecule, look Use photoelectrons to align molecule, look at fragmentation dynamicsat fragmentation dynamics
Photoelectrons for A and V
Rotation angle measured: 20 degreesRotation angle measured: 20 degrees
Rotation required by mass Rotation required by mass rearrangement: 21.6 degreesrearrangement: 21.6 degrees
Conclusion: Data is consistent with Conclusion: Data is consistent with
instantaneousinstantaneous rearrangement. rearrangement.
What is the longest time it could take ? What is the longest time it could take ? If additional 10 degrees,If additional 10 degrees,
L=2 from Auger decay, calculate L=2 from Auger decay, calculate omega(rotational) times rearrangement omega(rotational) times rearrangement time 10 degrees, gettime 10 degrees, get
Rearrangement time shorter than 60 fs. Rearrangement time shorter than 60 fs.
Calculated vibrational period for Calculated vibrational period for bending mode 10 fs. bending mode 10 fs.
The physicsLow energy collisions: Capture by highly charged ions
Ionization : continuum electrons
High energy collisions:
Small Z/v…photons
Fixed in space molecules: inner shells
Single electron processes
Two electron processes
Intense laser
Large Z/v
Large Z/v
Small Z/v…photons
Intense laser
B.Walker,B. Sheehy, L.F. DiMauro, B.Walker,B. Sheehy, L.F. DiMauro, P.Agontino, K.J.Schafer and K.C.Kulander, P.Agontino, K.J.Schafer and K.C.Kulander, Phys.Rev.Lett.73,1227(1994).Phys.Rev.Lett.73,1227(1994).
The Knee
SequentialTS2
Non-sequentialTS1
Sequential ionization Non-sequential
TS1, ShakeoffTS2 - like
Momentum spectra for He and Ne ions
Th. Weber, M. Weckenbrock, A. Staudte, L. Spielberger, O. Jagutzki, V. Mergel, F. Afaneh, G. Urbasch, M. Vollmer, H. Giessen, and R. Dörner, Phys.Rev.Lett. 84, 443 (2000).
R. Moshammer, B. Feuerstein, W. Schmitt, A. Dorn, C. D. Schröter, and J. Ullrich ,H. Rottke, C. Trump, M. Wittmann, G. Korn, K. Hoffmann, and W. Sandner, Phys.Rev.Lett. 84, 447 (2000).
2.9 1014 W/cm2
3.8 1014 W/cm2
6.6 1014 W/cm2
He Ne
Sequential ionization Non-sequential
Rescattering
Transition from NS to sequential for Ar
Th.Weber, M.Weckenbrock, A.Staudte, L.Spielberger, O.Jagutzki, V.Mergel, F.Afaneh, G.Urbasch, M.Vollmer, H.Giessen and R.Dörner, J.Phys.B 33, L127
(2000).
Increasing laser intensity
Below the knee:NS
Above the knee:SI
Ar 2+ p1 vs p2 along polarization vector
Th. Weber, H. Giessen, M. Weckenbrock, G. Urbasch, A. Staudte, L. Spielberger, O. Jagutzki, V. Mergel, M. Vollmer and R. Dörner , Nature 405, 658 (2000).
p1
p2
p2
p1
Off diagonal Ar 2+ momentum spectrum
B.Feuerstein, R.Moshammer, D.Fischer, A.Dorn, C.D.Schröter, J.Deipenwisch, R.R.Crespo Lopez-Urrutia, C.Höhr, P.Neumayer, J.Ullrich, H.Rottke, C.Trump, M.Wittmann, G.Korn and W.Sandner, Phys.Rev.Lett. 87, 043003 (2001).
classicallyallowed
excitationkinematics
Comparison of Ar and Ne p1 vs.p2 plotNe Ar
R.Moshammer, J.Ullrich, B.Feuerstein, et al., Optics Express 8, 358 (2001).
B.Feuerstein, R.Moshammer, D.Fischer, et al., Physs.Rev.Lett. 87, 043003 (2001).
Classically allowed rescattering ionization
Excitation plus laser ionization
R.Moshammer, J.Ullrich, B.Feuerstein, B.Fischer, A.Dorn, C.D.Schröter, J.R.Crespo Lopez-Urrutia, C.Höhr, H.Rottke, C.Trump, M.Wittmann, G.Korn K.Hoffmann and W.Sandner, J.Phys.B 36, L113 (2003).
. R.Moshammer, B.Feuerstein, D.Fischer, A.Dorn, C.d.Schroeter, J.Deipenwisch, J.R.Crespo Lopez-Urrutia, C. Hoehr, P.Neumayer and J.Ullrich, Optics Express 8, 358 (2001).
Ne double ionization electron energy spectra
Ne single ionization : dip in the middle
R.Moshammer, J.Ullrich, B.feuerstein, D.Fischer, A.Dorn, C.D.Schroeter, J.R.Crespo Lopez-Urrutia, C.Hoehr, H.Rottke, C.Trump, M.Wittmann, G.Korn and W.Sandner, to be published.
. R.Moshammer, B.Feuerstein, D.Fischer, A.Dorn, C.d.Schroeter, J.Deipenwisch, J.R.Crespo Lopez-Urrutia, C. Hoehr, P.Neumayer and J.Ullrich, Optics Express 8, 358 (2001).
-3 -2 -1 0 1 2 30
2000
4000
6000
8000
coun
ts
pion ||
[a.u]
semiclassical model(with rescattering)J. Chen, C. Nam PRA (2002) 053415
I = 0.7.1015 W/cm2
The physicsLow energy collisions: Capture by highly charged ions
Ionization : continuum electrons
High energy collisions:
Small Z/v…photons
Fixed in space molecules: inner shells
Single electron processes
Two electron processes
Intense laser
Large Z/v
Large Z/v
Small Z/v…photons
Intense laser on D2
Time of flight spectrum for laser on D2
time of flight [ns]
cou
nts
8 x 1014 W/cm2
t=100 fs
dd++ DD22++
Energy in eV of dEnergy in eV of d++
Polarization along time direction
What is all this structure?
Frazinski et al, PRL 83, 3625Frazinski et al, PRL 83, 3625
Bond softening : dissociationBond softening : dissociation
Zavriev et al., PRA , 1992.
This is what it is……….
time of flight [ns]
cou
nts
8 x 1014 W/cm2
t=100 fs
dd++ DD22++
Energy in eV of dEnergy in eV of d++
Bond softening and ATIBond softening and ATI
CREI double ionizationCREI double ionization
RescatteringRescattering
Evidence for rescattering double ionization in D2
Energy release of d+ pairs versusNet momentum of system
Circular polarization
Linear polarization
The rescattering component
d+ sum energy spectra from Laser + D2 > d+ + d+ + 2e
Linear Circular
Difference
0 20 Energy (eV)
0 20 Energy (eV) 0 20 Energy (eV)
RES
RES
CE
CE = Coulomb explosion via CREIRES = rescattering CE
d+ sum energy spectra from Laser + D2 > d+ + d+ + 2e
Linear Circular
Difference
0 20 Energy (eV)
0 20 Energy (eV) 0 20 Energy (eV)
RES
RES
CE
CE = Coulomb explosion via CREIRES = rescattering CE
The schematic
Niikura et al., Nature 417,917(2002)
The model and the clock
Electrons return at 2/3 of period plus integral number
of periods of 2.6 fs
CREI
Alnaser et al. Tong and Lin
How does the laser pulse compare to the pulse a passing charged particle makes?
-500 0 500
-0.4
-0.2
0.0
0.2
0.4
0.6Over barrier to make..
H2
++
H2
+
Ele
ctri
c F
ield
(a
.u.)
Time (a.u.)
Field from 25+ ion at v=.05 with b=7 a.u.
Field from 8 x 10 14 W/cm2 , 8 fs pulse
Comparison of field from laser pulse with that for a passing Xe 26+ ion
Summary
• Recoil momentum spectroscopy is widely applicable
• Collisions and pulses have much in common
CREDITS
The workersApologies to the theorists..J.Briggs, J.Feagin, A.Kheifets,R.E.Olson, C.D.Lin, ….
Ryan Kinney Natasha Maydanyuk
AhmadHasan
MichaelSchulz
Univ. Missouri at Rolla
Kansas State Univ.
M.Zamkov C.Wang M.Benis S.Voss L.Cocke A.Alnaser T.Osipov B.Shan C.Maharjan
A. Staudte, M. Trummel, T. Jahnke, M. Weckenbrock, Th. Weber, M. Hattaß, R. Grisenti, M. Schöffler, M. Balser, M. Odenweller, A. Gumberidze, L. Schmidt
J. Nickles, Th. Jalowi, M. Kaesz, R. Dörner, A. Knapp, C. Wimmer, J. Titze, H. Schmidt-Böcking
Univ. Frankfurt
Artem Rudenko, Vitor Bastos de Jesus, Robert Moshammer,
Daniel Fischer, Conny Höhr, Joachim Ullrich,
Christina Dimopoulou, Alexander Dorn, Bernold Feuerstein
MPI Heidelberg
CRYRING
Afshin Fardi
Jens Jensen
Henning SchmidtHenning
ZettergrenPeter
ReinhedHenrik
Cederquist
Thorsten Weber, Ph.D.R.Dörner, Boss
Part of the ALS Bunch
Osipov, Hertlein, Jahnke, Schriel, Cole, whole Dörner family, Prior, Benis
The EndThe End
The N2 movie
The f-wave enhancement in C2H4
Ovipov, KSU2003
Niikura et al., Nature 417,917(2002)