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Exploring atomic fragmentation with COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) Christina Dimopoulou Max-Planck-Institut für Kernphysik, Heidelberg IPHE, Université de Lausanne, 26.05.2003 Experiment - The “Reaction-Microscope” Atomic & Molecular Break-Up - Intense femtosec laser pulses - Ion induced femtosec fields Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields Momentum Spectroscopy: Principle champagne velocity, angle sparkling wine piccolo landing zone (detector) time-of-flight and landing position => initial velocity and angle i.e. initial momentum vector Recoil Ion Momentum Spectroscopy Cold Target: Reaction Microscope • supersonic atomic jet Detectors: • molecules • position sensitive • clusters • multi-hit Projectile: • single photons • intense lasers electrons • charged particles ~ meV recoil ions t;x,y,z) ~ eV Ion Time-of-flight Ex. Multi-photon ionisation of Ar ion trajectory +Uo 600 100000 10000 counts counts 400 1000 300 200100 100 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 N=11 p|| [a.u.] Ar+ + Ar 500 Ar++ Ar2+ N=12 N=13 H2O+ H2+ 1.8 eV N=14 10 0 1 40600 0 40650 40700 40750 20000 40000 TOF [ns] d 40800 60000 40850 80000 +U detector a Experiment - The “Reaction-Microscope” Atomic & Molecular Break-Up - Intense femtosec laser pulses - Ion induced femtosec fields Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields Single Photons . . . Intense Laser Target Jet Ion Detector Laser Electron Detector Ti:Sa Laser photon energy: 1.5 eV (T=2.7 fs) pulse length (FWHM): 30 fs intensity: Imax~1016 W/cm2 repetition rate: 3 kHz Multi-photon Single Ionisation electrons I h = 1.56 eV P = E /c 0 W/cm2 electron Ee = N h - Ip , N>10 Pe = - PR e 1013 ER = Ee/MR Ar1+ Intense Laser: Single Ionisation Drift momentum 2. I q p y (t0 ) E0 (t0 ) cos(t0 ) Single Photons . . . . Intense Laser pulse Ey(t) 1015 W/cm2 T=2/=2.7 fs t h = 80 eV: 1 photon h = 1.5 eV: > 17 photons 2 t 0 -1 Pion =-P =e450 t0 = 45 e1 = 900 t = 90 -2 1 -1 002 1 -2 -1 -4 0-3 Pion ion Pmomentum Helium p/a.u. electron y [a.u.] t = 00 Ey(t) = 00 tunneling 0 t0 = 0 py [a.u.] Helium ion momentum /a.u. Ne1+ 2 1 -2 4 0t = 450 -2 0 -2 0 = 90-4 -3 -2 -1 2 P3 4 -4 P ion Moshammer et al. PRL 2000 4 =30 2fs 1. px px He1+ electron 0 1 [a.u.] ppxy [a.u.] 2 3 4 -4 Intense Laser : Double Ionisation 3.1015 W/cm2 Ne2+ sequential non-sequential Orders of magnitude difference due to e-e correlation 1014 1015 Intensity W/cm2 Larochelle et. al J. Phys. B31 (1998) 1016 1.1015 W/cm2 Ne2+ Moshammer et al. PRL 2000 Ey(t) Ion Signal (arb. units) Ne2+ Ey(t) Ne1+ Non-sequential Double Ionisation shake - off 2+ Ne Ne2+ Ey(t) Fittinghoff et al 1992 coll. tunnelling Eichmann et al 1999 Double peak structure Time delay e1,e2 „rescattering“ Cor kum 1993 Kuchiev 1987 Schafer et al. 1993 ~ 200 a.u. Experiment - The “Reaction-Microscope” Atomic & Molecular Break-Up - Intense femtosec laser pulses - Ion induced femtosec fields Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields Ion Induced femtosec Fields Example: Electron Capture Ne7+ vP = 0.36 a.u. ppf Ne6+ ppi b~5 a.u. t I 3 1015 W/cm2 t b/ vp 0.3 fs pr He Electron Capture: Precision Spectr. Ne6+ Ne7+ ppf pp i Q pp pr vP = 0.36 a.u. He1+ pr tr a n s v e r s e m o m e n t u m / a u pr = Q |pp| pr|| = Q / vp - vp/2 6 pr 5 4 • scattering angle • impact parameter 3 2 1 0 Dynamics Structure 0 Fischer et al. JPB 2002 2 0 4 0 Q - v a lu e pr|| 6 0 / e V Q value: Q = Ebf - Ebi 8 0 •excellent resolution: 0.7eV FWHM •excellent precision: 3-100 meV •many states resolved simultaneously •no selection rules Scattering / mrad scatteringangle angle Q / mrad 0,4 0,3 0,2 0,1 0,0 10 20 30 40 50 60 70 Q-value / eV Q-value / eV capture into n=4 1500 1500 3 2s4s S 1 2s4p P 2s 4 1000 1,3 1000 3 2s4d D counts counts counts counts Electron Capture: Precision Spectr. FWHM 0.72 eV 1 2s4d D 500 1 2s4s S L x10 Projectile excitation 2p 3 500 2s 3 0 0 15 16 17 18 19 20 21 Q value // eV Q-value eV 22 23 24 25 10 20 30 40 50 Q value / eV Q-value / eV 60 70 Experiment - The “Reaction-Microscope” Atomic & Molecular Break-Up - Intense femtosec laser pulses - Ion induced femtosec fields Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields Studies with Highly Charged Ions Auger cascades HCI from HITRAP X-rays E~keV/amu t ≈ 1 fs Formation of ”hollow atoms” Questions: 1. Precision Spectroscopy 2. Dynamics of formation: Target many-electron flux (correlated?) 3. Rearrangement processes HCI The HITRAP Reaction Microscope • Increased Acceptance and Q-Value Resolution • Coincident detection of ions, electrons and photons large area ion detector with hole • multi-hit electron detector (up to 10 e ) • large area photon detectors • Gas jet Grid Electron detector +Uext Spectrometer plates Projectile beam 0V 0V Reaction volume Ion detector Drift tubes Experiment - The “Reaction-Microscope” Atomic & Molecular Break-Up - Intense femtosec Laser Pulses - Ion induced femtosec fields Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields Laser Assisted Electron Capture Laser & ion induced fields combined Laser I ~ 1013 W/cm2, ~ ns Ne7+ vP = 0.36 a.u. ppf Ne6+ ppi b~5 a.u. t I 3 1015 W/cm2 t b/ vp 0.3 fs pr He Laser Assisted Electron Capture ppf ppi Q pp pr pr pr = Q |pp| pr|| = Q / vp - vp/2 + pdrift (t0) 1013 W/cm2 Intensity Parameter Impact Scattering / mrad scatteringangle angle Q / mrad 0,4 0,3 0,2 0,1 0,0 10 20 30 40 50 60 70 Q-value / eV Q-value / eV Ion Longitudinal Momentum -03 -0.3 00 0.3 0.3 Ion Longitudinal Momentum Laser Assisted Electron Capture ppf ppi Q pr pr = Q |pp| pr|| = Q / vp - vp/2 + pdrift (t0) 0,4 T.Kirchner PRL 2002 1013 W/cm2 0,3 Intensity Parameter Impact Probability Scattering / mrad scatteringangle Q / mrad angle pp pr 0,2 0,1 0,0 10 20 30 40 50 60 70 Q-value / eV Q-value / eV Ion Longitudinal Momentum Impact Parameter -03 -0.3 00 0.3 0.3 Ion Longitudinal Momentum Laser Assisted Electron Capture ppf ppi Q pr pr = Q |pp| pr|| = Q / vp - vp/2 + pdrift (t0) 0 ,4 T.Kirchner PRL 2002 1013 W/cm2 0 ,3 Intensity Parameter Impact Probability Scattering / dmrad scatte rin gangle ang Q le / m ra pp pr 0 ,2 0 ,1 0 ,0 10 20 30 40 50 60 70 Q-value / eV Ion Longitudinal Impact Parameter Momentum Q - v a lu e / e V 1500 1 ,3 -03 -0.3 00 0.3 0.3 Ion Longitudinal Momentum Experiment - The “Reaction-Microscope” Atomic & Molecular Break-Up - Intense femtosec Laser Pulses - Ion induced femtosec fields Future - Studies with HCI : HITRAP - Laser assisted collisions - Sub-attosec ion induced fields Sub-attosecond Ion Induced Fields 1 GeV/amu U92+ : =2, vp = 120 a.u. + He b=2 a.u. <Te> 40 as I 1020 W/cm2 “Instantané” of the initial two (many)-electron wave function + e- Bapat et al. JPB 2000 Ex. Double ionisation of He by 100 MeV/amu C6+ t b/ ( vp ) =0.2 as He2+ Heisenberg’s as microscope Sub-attosecond Ion Induced Fields Heisenberg’s as microscope Intense relativistic HCI beams at GSI 100 m ESR storage ring 1 ns, 1 MHz Max-Planck Institut, Heidelberg • R. Moshammer, H. Kollmus, D. Fischer, B. Feuerstein, C. Höhr, • A. Dorn, C.D. Schröter, A. Rudenko, C. Dimopoulou, • K. Zrost, V. Jesus, J. R. Crespo Lopez-Urrutia, • A. Voitkiv, T. Kirchner, J. Ullrich UMR, Rolla GSI, Darmstadt S. Hagmann, R. Mann M. Schulz, R.E. Olson, D. Madison Max-Born Institut, Berlin H. Rottke, C. Trump, E. Eremina, W. Sandner Navrangpura, India B. Bapat E Curve Crossing Model E Curve Crossing Model Electron Capture: Precision Spectr. N e 7+ + He E N e 6+(2s 4) E + H e+ N e 6+(2p 3) + He + N e 6+(2s 3) + H e + r Q-value / eV Ne 7+ + He Ne 6+ (2s4) + He+ Ne 6+ (2p 3 ) + He + Ne 6+ (2s3) + He+ r Q-value / eV way in way in QC way out Qc = Q / 2E Half coulomb QC angle way out Qc = Q / 2E Half coulomb angle Recoil Ion Momentum Spectroscopy Helmholtz coils: electrons B-field drift Electron detector recoil ions E-field projectile beam supersonic gas-jet Ion detector Reaction Microscope d Ar2+ Y Axis Ar++ Ar+ 250 detector a 200 Ar++ 150 Ar+ 1 cm 100 Ar2+ 50 +Uo +U 0 0 50 100 150 X Axis 200 250 Intense Laser: Single Ionisation Drift momentum 2. I q p y (t0 ) E0 (t0 ) cos(t0 ) Single Photons . . . . Intense Laser W/cm2 T=2/=2.7 fs t h = 80 eV: 1 photon I Ponderomotive p y,max 2q U P U P 2 h = 1.5 eV: >417 potential photons 4 0 -1 -2 4 Ne1+ 2 2 1 = 00 = 450 = 900 t0 = 0 t t0 = 45 t = 90 -2 1 -1 002 1 -2 -1 -4 0-3 Pion ion Pmomentum Helium p/a.u. electron y [a.u.] t = 00 py [a.u.] Helium ion momentum /a.u. =30 2fs 1. px px He1+ 0t = 450 -2 0 -2 0 = 90-4 -3 -2 -1 2 P3 4 -4 P ion Moshammer et al. PRL 2000 Ey(t) 1015 Ey(t) pulse electron 0 1 [a.u.] ppxy [a.u.] 2 3 4 -4 Rescattering: Dynamics Ey(t) I 1015W / cm 2 t t0 y(t) T / c 2.7 fs e1 Ne2+ e1 Ne1+ time delay Ne2+ e2