Intense laser field interaction with molecular ions Daniel Strasser Institute of Chemistry

1. Intense laser field interaction with molecular ions Daniel Strasser Institute of Chemistry Hebrew University of Jerusalem Batsgeva De Rothschild Seminar 2012 Ultrafast laser – molecular ion lab Ultrafast EUV Probe Project 2013 time Oct 2009 2011

2. Ultrafast EUV Probe for Molecular Reaction Dynamics Time resolved single photon Coulomb explosion imaging

3. R• + NH3 R-NH2 + (H•)hot e- - molecule reactions exhibit extremely non-B.O. dynamics example: ECD of Biomolecules ( Electron Capture Dissociation ) R-N+H3 + e- (R-NH3)•* superexcited state R.A. Zubarev et al. EJMS (2002)

4. Molecular cloud Barnard 68 European Southern Observatory: Alves, J. F., Lada, C. J., and Lada, E. A. H3+ DR (fragment imaging) 10 5 0 e- - molecule reactions are everywhere example: Dissociative Recombination of molecular ions superexcited H3 state e- H3+ D. Strasser et al. PRL (2001)

5. Time resolved probing of e- – molecule reactions New basic insights beyond B.O. into chemical reactions

6. Can we time resolve e- – molecule dynamics ? Need Ultrafast EUV Photons AB+ + e- AB** (SES) AB + hn A + B*

7. Ultrafast EUV shources: table top HHG sources: “simply” focusing intense IR into rare gas Accelerator based FEL facilities: ( LCLS, FLASH, …) ~5x1014W/cm2in 10 PSI Ar ≥ 106 photons/15th/pulse

8. N2+ + e- N2** (SES) N2 + hn N + N* Ultrafast SES dynamics Pump: 53.7 nm Probe: 800 nm Ultrafast Predissociation time ≤ 25 fs short lived N* (3d or 4p) at Berkeley with Steve Leone D. Strasser et al. Mol. Phys. (2008)

9. Anionic Superexcited States AB + e- NIR-VIS photons AB**- (SES) AB- + hn A- + B* • other advantages: • mass selectivity • fast beam fragment imaging

10. My Dream

11. and now with Coherent Control …

12. Laser system: • Mai-Tai Oscillator • Spitfire Amplifier • ------------------------- • < 25 fs • < 4 mJ/pulse • @ 1kHz • OPA-800 Pulse Shaper ----------------------------- 128 spectral pixels of phase & amp. control amplifier oscillator

13. { vi} vbeam Fast beam fragment imaging shaped ultrafast, or pump-probe pulses imaging detector measure molecule {xi, yi, ti} ~1,000,000 m/s t ~ ns x ~ cm L Coincidence detection of all possible products: Cations, Anions, Neutrals and electrons

14. { vi} vbeam Fast beam fragment imaging shaped ultrafast, or pump-probe pulses imaging detector measure molecule {xi, yi, ti} ~1,000,000 m/s L mass gate electrodes pulsed ion beam

15. { vi} vbeam Fast beam fragment imaging ultrafast pump-probe pulses imaging detector measure molecule {xi, yi, ti} ~1,000,000 m/s L Experiments that are now possible: -Photodetachment, Photodissociation -Intense laser field – anion interaction -Pulse shaping, Coherent control and more -Coulomb explosion -Pump-Probe : Time resolve SES dynamics

16. test: H2O- photodetachment Water ion clusters (H2O) 17- Unfocused laser Photodetachment ( neutral products )

17. in situ measurement of the volume effect probed with linear photodetachment z Ion beam

18. Calculated Peak Intensities z Ion beam

19. linear photodetachment modeling of the volume effect z Ion beam

20. 1st model system: SF6 + e- SF6- studies will be extended to SF6 , H2O, and Ar based clusters

21. 1st model system: SF6 + e- U SF6 SF5- +F ~3eV SF6- ~1.1eV 1.57 Å 1.73 Å R ( S-F )

22. SF6- Energetics e- Photodetachment efficiency curve (PDE) measurement with tunable wavelength ns laser (in collaboration with Oded Heber WIS) Neutral yield [a.u.] ΔEv ~ 0.1 eV hv [eV]

23. SF6- Energetics e- Photodetachment efficiency curve (PDE) measurement with tunable wavelength ns laser (in collaboration with Oded Heber WIS) 800 nm

24. SF6- non-linear photodetachment ~40 fs 800 nm balance between peak intensity and volume effect (~2×1014 W/cm2 ) z Ion beam

25. SF6- non-linear photodetachment @800nm peak intensity (~6×1014 W/cm2 )

26. Can we remove more than one electron ? 3 Step model for intense field interaction with neutral species (1) (3) And is this picture at all useful for anions ?

27. To remove the next electron we need >10 more photons SF6 Dissociative Ionization data NIST chemistry webbook No one was able to observe a stable SF6+

28. Double detachment observed @ 5x1014 W/cm2

29. higher order processes – double detachment SF6- products @ I ≥ 1015 W/cm2 SIMION simulation SF2-5+ SF+ S+ F+ SF6+ neutrals

30. higher order processes – double detachment SF6- products @ I ≥ 1015 W/cm2 SIMION simulation add 1eV KER SF2-5+ SF+ S+ F+ SF6+ neutrals

31. Polarization F+ emitted along TOF axis

32. Correlated F+ and S+ originate from Coulomb explosion events Neutrals RG background S+ F+ F+

33. Chirp effect ? F+ Neutrals

34. TOD effect ? F+ Neutrals

35. Polarization effect ?

36. Students:Non-linear detachment :YishaiAlbeckPDE curve measurements: Itamar Luzon Collaborations: Oded Heber (Weizmann ) Ori Cheshnovsky (TAU) Funding: • ERC • Legacy Heritage fund (מורשה) • EU PF7 people program (MC IRG) • Farks center for light induced processes • James Franck fund (light matter interactions)

37. Time Resolved Dynamics e- e- e- Ultrafast Laser Pulses M.Sc., Ph.D., and Postdoc positions available Funding: • ERC • Legacy Heritage fund (מורשה) • EU PF7 people program (MC IRG) • Farks center for light induced processes • James Franck fund (light matter interactions)