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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0

500

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1500

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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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