Heidelberg 1999 – wissenschaftliches Programm

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SYLF: Symposium Wechselwirkung in starken Laserfeldern

SYLF III: HV III

SYLF III.1: Hauptvortrag

Montag, 15. März 1999, 11:30–12:00, zo1

Atomic and molecular cluster jets in strong and ultrashort laser fields — •Martin Schmidt¹, S Dobosz¹, M Lezius¹, C Ellert¹, Dider Normand¹, D Vernhet², J-P Rozet², A Faenov³, T Pikuz³, and I Skobelev³ — ¹CEA - DSM/DRECAM/SPAM, Bat. 524, 91191 Gif-sur-Yvette, Frankreich — ²GPS-PIIM, Universite Paris 6, 75251 Paris Cedex 05 — ³MISDC, VNIIFTRI, Mendeleevo, 141570 Russia

We have irradiated big atomic and molecular clusters with intense and ultrashort laser pulses. We observe the emission of highly charged and fast atomic ions and of X-rays. A novel magnetic deflection time of flight technique, used to analyze the ionic outcome, reveals two main explosion mechanisms in the case of neat rare gas clusters. Whereas one mechanism is related to the hydrodynamic pressure within the so-called cluster-sized nanoplasmas, the other is due to Coulomb repulsion. Our X-ray spectroscopic studies confirm the existence of highly charged ions in Argon nanoplasmas and we observe in particular He-like Argon transitions. In the case of CO₂ molecular clusters, the X-ray spectra of H- and He-like Oxygen lines strongly suggest the rapid explosion of the plasma together with the ejection of an important amount of MeV ions. Finally, for these molecular clusters opacity effects are clearly observed.