Laser-plasma interaction and ablative acceleration of thin foils at 1012–1015 W/cm2

Abstract

The interaction physics and hydrodynamic motion of thin‐foil targets irradiated by long, low‐flux Nd‐laser pulses (3 nsec, 10¹²–10¹⁵ W/cm²) are studied experimentally and compared with theoretical models. Laser light absorption is high (80%–90%) and thin‐foil targets are accelerated up to 10⁷ cm/sec with good (20%) hydrodynamic efficiency in the 10¹²–10¹³ W/cm² range. These results agree with a simple rocket ablation model. Details of thermal heat flow, both axially (related to ablation depth) and laterally (related to beam uniformity requirements), are also presented.