Post on 21-Mar-2016
description
Christina DimopoulouMax-Planck-Institut fr Kernphysik, Heidelberg
IPHE, Universit de Lausanne, 26.05.2003
Exploring atomic fragmentation with COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy)
Atomic & Molecular Break-Up - Intense femtosec laser pulses - Ion induced femtosec fieldsExperiment - The Reaction-Microscope
Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields
Momentum Spectroscopy: Principlelanding zone(detector)velocity,angletime-of-flight and landing position => initial velocity and angle i.e. initial momentum vector
electrons position sensitive multi-hitProjectile:Cold Target: supersonic atomic jet molecules clustersDetectors:recoilionsE-fieldRecoil Ion Momentum Spectroscopy single photons intense lasers charged particles t;x,y,z) ~ eVB-field ~ meVReaction Microscope
Ion Time-of-flight Ex. Multi-photonionisation of Ar
Atomic & Molecular Break-Up - Intense femtosec laser pulses - Ion induced femtosec fieldsExperiment - The Reaction-Microscope
Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields
Single Photons . . . Intense LaserTarget JetLaserIon DetectorElectron DetectorTi:Sa Laserphoton energy: 1.5 eV (T=2.7 fs)pulse length (FWHM): 30 fsintensity: Imax~1016 W/cm2repetition rate: 3 kHz
e1
Ee
Ee
Weak Field:
Photo Absorption(Einstein 1905)
Ee ~
Stronger Field:
Multi-PhotonIonisation(Gppert-Meier 1931)
Strong Field:
Tunnel -Ionisation
Multi-photon Single Ionisationelectrons
Intense Laser: Single Ionisation =30 fs Ey(t)tI 1015 W/cm2 pulseT=2/=2.7 fs Drift momentum2.1.
Intense Laser : Double IonisationsequentialLarochelle et. al J. Phys. B31 (1998)Orders of magnitude difference due to e-e correlation1.1015 W/cm2non-sequential3.1015 W/cm2Moshammer et al. PRL 2000
Ne1+
Ne2+
1014
Ion Signal (arb. units)
Intensity W/cm2
1015
1016
Non-sequential Double IonisationKuchiev 1987Schafer et al. 1993Ne2+
shake - off
Fittinghoff et al 1992
coll. tunnelling
Eichmann et al 1999
e1,e2
Atomic & Molecular Break-Up - Intense femtosec laser pulses - Ion induced femtosec fieldsExperiment - The Reaction-Microscope
Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields
Ion Induced femtosec FieldsExample: Electron Capture
Electron Capture: Precision Spectr.
Electron Capture: Precision Spectr.capture into n=4excellent resolution: 0.7eV FWHM excellent precision: 3-100 meVmany states resolved simultaneouslyno selection rules
10
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0,0
0,1
0,2
0,3
0,4
Q-value / eV
scattering angle
Q
/ mrad
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Projectile excitation
x10
2s 3
l
2p 3
l
2s 4
l
1,3
L
counts
Q value / eV
Scattering angle / mrad
Q-value / eV
counts
Q-value / eV
FWHM 0.72 eV
2s4d
1
D
2s4d
3
D
2s4p
1
P
2s4s
1
S
2s4s
3
S
counts
Q value / eV
Q-value / eV
counts
Atomic & Molecular Break-Up - Intense femtosec laser pulses - Ion induced femtosec fieldsExperiment - The Reaction-Microscope
Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields
Studies with Highly Charged IonsPrecision Spectroscopy Dynamics of formation: many-electron flux (correlated?)3. Rearrangement processesQuestions:Formation of hollow atomst 1 fs
The HITRAP Reaction Microscope Increased Acceptance and Q-Value Resolution Coincident detection of ions, electrons and photons
Atomic & Molecular Break-Up - Intense femtosec Laser Pulses - Ion induced femtosec fieldsExperiment - The Reaction-Microscope
Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields
Laser Assisted Electron CaptureLaser & ion induced fields combinedLaserI ~ 1013 W/cm2, ~ ns
-03 0 0.3Laser Assisted Electron CaptureIntensity1013 W/cm2Ion Longitudinal MomentumImpact ParameterIon Longitudinal Momentum+ pdrift (t0)
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Q-value / eV
scattering angle
Q
/ mrad
Scattering angle / mrad
Q-value / eV
-03 0 0.3Laser Assisted Electron CaptureImpact ParameterIon Longitudinal MomentumT.Kirchner PRL 2002+ pdrift (t0)-03 0 0.3Intensity1013 W/cm2Ion Longitudinal Momentum-0.3 0 0.3
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0,0
0,1
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Q-value / eV
scattering angle
Q
/ mrad
Scattering angle / mrad
Q-value / eV
-03 0 0.3Laser Assisted Electron CaptureImpact ParameterIon Longitudinal MomentumT.Kirchner PRL 2002-03 0 0.3Intensity1013 W/cm2Ion Longitudinal Momentum-0.3 0 0.3
Scattering angle / mrad
Q-value / eV
counts
Q-value / eV
Atomic & Molecular Break-Up - Intense femtosec Laser Pulses - Ion induced femtosec fieldsExperiment - The Reaction-Microscope
Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields
Sub-attosecond Ion Induced FieldsHeisenbergs as microscopeInstantan of the initial two (many)-electronwave function
Sub-attosecond Ion Induced FieldsHeisenbergs as microscope
R. Moshammer, H. Kollmus, D. Fischer, B. Feuerstein, C. Hhr, A. Dorn, C.D. Schrter, A. Rudenko, C. Dimopoulou, K. Zrost, V. Jesus, J. R. Crespo Lopez-Urrutia, A. Voitkiv, T. Kirchner, J. UllrichMax-Planck Institut, HeidelbergH. Rottke, C. Trump, B. BapatE. Eremina, W. SandnerUMR, RollaM. Schulz, R.E. Olson, D. MadisonMax-Born Institut, Berlin Navrangpura, IndiaGSI, DarmstadtS. Hagmann, R. Mann
Electron Capture: Precision Spectr.
Curve Crossing Model
c = Q / 2E Half coulomb angle
Ne7+ + He
Ne6+(2s4) + He+
Ne6+(2p3) + He+
Ne6+(2s3) + He+
r
E
Q-value / eV
E
Q-value / eV
c
way in
way out
Scattering angle / mrad
Curve Crossing Model
c = Q / 2E Half coulomb angle
Ne7+ + He
Ne6+(2s4) + He+
Ne6+(2p3) + He+
Ne6+(2s3) + He+
r
E
Q-value / eV
E
Recoil Ion Momentum Spectroscopy
Reaction Microscope
Intense Laser: Single Ionisation =30 fs Ey(t)tI 1015 W/cm2 pulseT=2/=2.7 fs Drift momentum1.2.
tunnelling
Pion =-Pe 0
e1
Rescattering: DynamicstEy(t)y(t)e1Ne1+e2e1Ne2+time delayt0