Alternative efficient methods of dense plasma objects acceleration to high velocities

摘要

Numerical modelling of dense plasma objects acceleration was performed. In these investigations a scheme called "cavity pressure acceleration" (CPA) was applied, which allows propelling plasma objects in arbitrary direction in relation to laser beam incident on a target and more efficient absorption of laser pulse energy. Those calculations complement previously performed experiments on the PALS system, in which results of acceleration of dense plasma objects (average speed obtained for 20 μm polystyrene and 10 μm Al targets was ~ 6×10~7 cm/s) were at the level of the top global results. Numerical calculations were made for two different laser wavelengths: λ= 1.315 μm (iodine laser) and λ= 0,248 μm (KrF laser). For the "classic" i.e. ablative drive scheme, the advantage of using a short wavelength laser is obvious. Velocities obtained in this variant are two-two and a half times higher than in the case of using a laser with several times longer wave. Numerical calculations, as well as previous experiments on the PALS system, show that the use of "non-classic" drive schemes enables comparable, very good results to be obtained also with lasers of longer wavelength.