Frankfurt 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
A: Atomphysik
A 16: Wechselwirkung mit starken Laserpulsen I
A 16.6: Vortrag
Donnerstag, 16. März 2006, 11:55–12:10, H6
Nonlinear resonant absorption in intense laser-cluster interaction — •Mrityunjay Kundu and Dieter Bauer — Max-Planck-Institut für Kernphysik, Postfach 103980, 69029 Heidelberg, Germany
Energy absorption by clusters in intense laser fields is known to be particularly efficient. It is known from computer simulations that collisional absorption does not play a major role at laser wavelengths ≥ 800 nm. Although various mechanisms of collisionless absorption in clusters have been proposed it is not easy to identify, to validate (or invalidate) and to separate them by investigating the outcome of computer simulations.
It is well known that the occurrence of the linear resonance ωlaser=ωMie during the cluster expansion leads to efficient absorption of laser energy and cluster ionization. In this work, instead, we focus on the ultrashort laser pulse-regime or the early cluster dynamics in the long pulse-regime where the above linear resonance condition is not fulfilled. We show that even in this case absorption is efficient and that the dominant absorption mechanism in this regime is nonlinear resonance absorption (NRA) [1,2]. We prove this assertion by clearly identifying NRA in particle-in-cell (PIC) simulations of XeN clusters (with N up to 14000) in intense laser fields.
[1] Toshihiro Taguchi and Thomas M. Antonsen Jr., Howard M. Milchberg, Phys. Rev. Lett. 92, 205003 (2004)
[2] P. Mulser and M. Kanapathipillai, Phys. Rev. A 71, 063201 (2005)