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Christophe Huchon

Nanoscale Physics Research Laboratory. School of Physics and Astronomy. The University of Birmingham. United Kingdom. Time of flight measurement of femtosecond ablation of graphite. Christophe Huchon. Attosecond meeting, 7 december 2005, Rutherford Appleton Laboratory.

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Christophe Huchon

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  1. Nanoscale Physics Research Laboratory School of Physics and Astronomy The University of Birmingham United Kingdom Time of flight measurement of femtosecond ablation of graphite Christophe Huchon Attosecond meeting, 7 december 2005, Rutherford Appleton Laboratory

  2. Motivation: mechanism(s) in femtosecond laser ablation ? TOF Products ONLY from surface ? TOF Products from surface + fragmentation ? Thermal (equilibrium) or/and coulomb explosion (non equilibrium)?

  3. LAYOUT PUMP-PROBE Nd:YLF 1 kHz l = 527 nm Up to 25 mJ Ti:Sapphire, 82 MHz, 800 nm, 100 fs, 600 mW Transfer arm Regenerative Amplifier 1 kHz 100 fs Up to 2 mJ STM chamber Time-of-flight spectrometer Ablation chamber Ar+ laser All lines 6 W PMT Differential pumping chamber HHG chamber Argon gas flow

  4. Source/extraction Drift region Detector E1 = V/s E2 = 0 V s D Principle of TOF spectrometer  Ions desorbed from surface: if D >> s

  5. Model used for ablation process

  6. pulse= 100 fs Epulse= 200 J Usample= 500 V Ratio ≈ 11

  7. pulse= 100 fs Epulse= 10.5 J Usample= 405 V

  8. KE distribution spread as a function of the voltage pulse= 100 fs Epulse= 10.5 J

  9. Summary • fragmentation process involved in the ablation of the graphite with femtosecond laser pulse. • need to find what is the rate thermal vaporization / Coulomb explosion  VUV probe • VUV, XUV will allow time-resolved photoelectron emission

  10. Acknowlegdement • Andrey Kaplan • Miklos Lenner • Quanmin Guo • Richard Palmer

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