Download presentation
Presentation is loading. Please wait.
Published bySamira Frizzell Modified over 10 years ago
1
Momentum Imaging in Atomic Collision Physics BREADTH : MICROMODEL OF ICPEAC WHAT IS IT? FOCUS: DOUBLE IONIZATION ICPEAC 2003
2
BREADTH: MODEL OF ICPEAC ? ICPEAC 2003 EVENT BY EVENT MOMENTUM IMAGING ION-ATOM COLLISIONS COLLISIONS IN MOTS USE TO ANALYZE MOT IONIZATION WITH INTENSE LASER PULSES WITH SYNCHROTRON RADIATION OF MOLECULES WHICH EXPLODE
3
Conceptual COLTRIMS p p p’ Projectile Electron Recoil Single detectors p p B E Imaging pp p’
4
THE DETECTOR The detector Well, not really, but the idea is similar CMS detector at Fermilab Cold Target Recoil Ion Momentum Spectroscopy
5
E BCOILS POSITION AND TIME SENSITIVE DETECTORS P ALONG BEAM FROM TIME P TRANSVERSE FROM POSITION REACTION THE BASIC DETECTOR
6
CHOOSE ONE OF EACH E B COILS POSITION AND TIME SENSITIVE DETECTORS LASER BEAM SYNCHROTRONRADIATION PHOTON BEAM ION BEAM (SUPERSONIC)JET /4 MOT BEAM TARGET DETECTOR
7
CLASSIC CONFIGURATION : IONS ON JETS E BCOILS POSITION AND TIME SENSITIVE DETECTORS ION BEAM SUPERSONICJET
8
VARIATION ONE: PHOTONS ON JETS E BCOILS POSITION AND TIME SENSITIVE DETECTORS SUPERSONICJET SYNCHROTRONRADIATION PHOTON BEAM
9
VARIATION TWO: LASERS ON JETS E BCOILS POSITION AND TIME SENSITIVE DETECTORS SUPERSONICJET LASER BEAM
10
VARIATION THREE: ION BEAMS ON MOT E BCOILS POSITION AND TIME SENSITIVE DETECTORS ION BEAM /4 MOT
11
VARIATION FOUR: LASER BEAMS ON MOT E BCOILS POSITION AND TIME SENSITIVE DETECTORS /4 MOT LASER BEAM
12
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.
13
The physics Low 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 Small Z/v…photons Capture by highly charged ions
14
Electric field caused by a passing Xe 26+ ion
15
Q spectra for capture from He by Ar 16+ ions M.Abdallah, W.Wolff, H.E.Wolf, E.Y.Kamber,M.Stockli and C.L.Cocke, Phys.Rev.A 58, 2911(1998).
16
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+ + He O 4+ (nl,n’l’) + He ++ O 5+ + e Auger
17
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. p z of recoil
18
Q-value spectra from Ar 8+ on atomic hydrogen Experiment:Erge Edgu- Fry, Ph.D.Thesis Theory: Lee and Lin, Close coupling AO Relative populations (%) ExperimentTheory 5s8.18.5 5p14.619.6 5dfg29.843.4 Sum 552.571.6 6s3.313.2 6p32.56.3 6dfg10.48.9 Sum 646.328.4
19
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. thesis Orsted Institute, Univ. Copenhagen ~ 10 -6 rad
20
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
21
KSU MOTRIMS Cs + R. Brédy, H. Nguyen, H. A. Camp, X. Flechard and B. D. DePaola, J.R.Macdonald Laboratory, Kansas State Univ.
22
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)
23
The physics Low 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 Small Z/v…photons Ionization: continuum electrons
24
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
25
Electron spectra for He + on He M.A.Abdallah et al., Phys.Rev.81, 3627 (1998). He + e 1 eV
26
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).
27
The physics Low 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 Small Z/v…photons Single electron processes
28
Electron ejection by charged particle: large q vs small q Small q………. “optical limit” Large impact parameter Projectile delivers energy only Sets positive charge in Oscillation against negative charge Large q exchange with one electron Rest of atom is spectator (Rutherford and Marsden) V~ e i q.r
29
Single photoionization recoils 80 eV Single Ionization of He k recoil ion = -k e h R. Doerner et al., Phys. Rev. Lett. 76, 2654 (1996).
30
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).
31
Kinematically complete: electron spectra for experimentally controlled q Photons Charged particles q “binary” “recoil” He + e-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 electrons q=1.5 a.u.
32
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 momentum transfer not being treated correctly.
33
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).
34
The physics Low 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 Small Z/v…photons Two electron processes
35
Two electron removal: how to do it? TS2 TS1 L.H.Andersen, H.Knudsen, P.Hvelplund, et al., Phys.Rev.Lett. 57, 2147 (1986).
36
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 He q He ++ ee Double ionization: Electron pair ejection Single ionization 3.6 Mev/ Se 28+ on He M oshammer et al.,Phys.Rev.A 56, 1351 (1997).
37
The small perturbation case TS1 collision Shakeoff Small Z/v or photon
38
Electron distributions: photodouble ionization of He k + = k 1 +k 2 k - =(k 1 -k 2 )/2 Jacobi k 1,k 2 Lab k1k1 k2k2 k+k+ k-k- selections rules A=0 implies electrons in state E1 selection rules plus ee repulsion; No back to back, no parallel emission Opening angle around 120 degrees J S Briggs and V Schmidt, J.Phys.B 33, R1 (2000).
39
1 eV Photodouble ionization of He Electron momenta 20 eV excess energy k + = k 1 +k 2 k 1, k 2 k - = (k 1 -k 2 )/2 H. Braeuning, R. Doerner, C.L. Cocke, M.H. Prior et al., J. Phys. B30, L649 (1997).
40
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).
41
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 fast slow
42
Photodouble ionization of H 2 : 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 H 2 : Node is There but relaxed Node on cone where no dipole moment of system along polarization vector Walter and Briggs, PRL 85, 1630 (2000).
43
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 ExperimentTheory (Kheifets) Soft electrons are shaken off
44
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
45
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
46
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 p z fast protons on He, capture one, make He ++
47
Charged particle “dipole” double ionization Photons k + =k 1 +k 2 k - =(k 1 -k 2 )/2 Jacobi k 1,k 2 Lab Charged particles q “binary” “recoil” “binary” q He ++ ee
48
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 11 22 11 22
49
The physics Low 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 Small Z/v…photons Fixed in space molecules: Inner shells
50
Illuminating molecules from within hv + CO CO + (1s -1 ) + e - (photoelectron) (few eV) (10 –17 s) CO 2+ + e - (Auger) (high energy)(10 –14 s) C + + O + (10 –13 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 LBNLMichael H. Prior, Jürgen Rösch, Andre Staudte Western Michigan U.Allen Landers Guest: Amine Cassimi (Ganil/Ciril)
51
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 in potential well of molecule Depends on external radiation
52
The sigma (f-wave) resonance in CO is the photoelectron momentum vector as you scan the photon energy A.Landers, in “Photonic, Electronic and Atomic Collisions”, ed. J.Burdoerger et al., p. 149 (Rinton, Princeton, 2002).
53
Steps of process and energetics C2H2+C2H2+ C2H2C2H2C2H2C2H2 C 2 H 2 ++ h = 309 eV Photoelectron Auger D.Duflot et al., J.Chem.Phys.10 2,1(1995). KER spectrum T.Osipov,KSU 10 20 10 20 KER Vinylidene channel
54
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!
55
Is there an f-wave resonance in C 2 H 2 ? B.Kempgens et al., PRL 79, 35 (1997).
56
The f-wave enhancement in C 2 H 4 Osipov, KSU, 2003
57
Comparison of C 2 H 2 and C 2 H 4 Recoil momentum spectra of near symmetric breakup for mass 24 or 26
58
Acetylene/Vinylidene
59
Can the angular distributions tell about the fragmentation dynamics? EXPT Th.Weber et al., JPB 34, 3669 (2001). THEORY R.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 ).
60
Use fragments to align molecule, look at photoelectron distributions Photoemission C 2 H 2 + 10 -17 secSlow? Fast? CH 2 + C + CH + Auger C 2 H 2 ++ 10 -14 sec Lose molecule-photoelectron angle Keep molecule-photoelectron angle Use photoelectrons to align molecule, look at fragmentation dynamics
61
Photoelectrons for A and V Rotation angle measured: 20 degrees Rotation required by mass rearrangement: 21.6 degrees Conclusion: Data is consistent with instantaneous rearrangement. What is the longest time it could take ? If additional 10 degrees, L=2 from Auger decay, calculate omega(rotational) times rearrangement time 10 degrees, get Rearrangement time shorter than 60 fs. Calculated vibrational period for bending mode 10 fs.
62
The physics Low 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 Small Z/v…photons Intense laser
63
B.Walker,B. Sheehy, L.F. DiMauro, P.Agontino, K.J.Schafer and K.C.Kulander, Phys.Rev.Lett.73,1227(1994). The Knee Sequential TS2 Non-sequential TS1
64
Sequential ionization Non-sequential TS1, Shakeoff TS2 - like
65
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 10 14 W/cm 2 3.8 10 14 W/cm 2 6.6 10 14 W/cm 2 He Ne
66
Sequential ionization Non-sequential Rescattering
67
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
68
Ar 2+ p 1 vs p 2 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). p1p1 p2p2 p2p2 p1p1
69
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). classically allowed excitation kinematics
70
Comparison of Ar and Ne p 1 vs.p 2 plot Ne 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
71
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
72
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). semiclassical model (with rescattering) J. Chen, C. Nam PRA (2002) 053415 I = 0.7. 10 15 W/cm 2
73
The physics Low 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 Small Z/v…photons Intense laser on D 2
74
Time of flight spectrum for laser on D 2 time of flight [ns] counts 8 x 10 14 W/cm 2 t=100 fs d+d+d+d+ D2+D2+D2+D2+ Energy in eV of d + Polarization along time direction
75
What is all this structure? Frazinski et al, PRL 83, 3625 Bond softening : dissociation Zavriev et al., PRA, 1992.
76
This is what it is………. time of flight [ns] counts 8 x 10 14 W/cm 2 t=100 fs d+d+d+d+ D2+D2+D2+D2+ Energy in eV of d + Bond softening and ATI CREI double ionization Rescattering
77
Evidence for rescattering double ionization in D 2 Energy release of d + pairs versus Net momentum of system Circular polarization Linear polarization
78
The rescattering component
79
The schematic Niikura et al., Nature 417,917(2002)
80
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
81
How does the laser pulse compare to the pulse a passing charged particle makes? Comparison of field from laser pulse with that for a passing Xe 26+ ion
82
Summary Recoil momentum spectroscopy is widely applicable Collisions and pulses have much in common
83
CREDITS The workers Apologies to the theorists.. J.Briggs, J.Feagin, A.Kheifets, R.E.Olson, C.D.Lin, ….
84
Ryan Kinney Natasha Maydanyuk Ahmad Hasan Michael Schulz Univ. Missouri at Rolla
85
Kansas State Univ. M.Zamkov C.Wang M.Benis S.Voss L.Cocke A.Alnaser T.Osipov B.Shan C.Maharjan
86
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
87
Artem Rudenko, Vitor Bastos de Jesus, Robert Moshammer, Daniel Fischer, Conny Höhr, Joachim Ullrich, Christina Dimopoulou, Alexander Dorn, Bernold Feuerstein MPI Heidelberg
88
CRYRING Afshin Fardi Jens Jensen Henning Schmidt Henning Zettergren Peter Reinhed Henrik Cederquist
89
Thorsten Weber, Ph.D. R.Dörner, Boss
90
Part of the ALS Bunch Osipov, Hertlein, Jahnke, Schriel, Cole, whole Dörner family, Prior, Benis
91
The End
92
The N 2 movie
93
The f-wave enhancement in C 2 H 4 Ovipov, KSU 2003
94
Niikura et al., Nature 417,917(2002)
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.