Laser Interaction and Compression Studies at the Rutherford Appleton Laboratory

Abstract

Experimental observations and numerical simulations covering several physical processes involved in laser interaction with matter and laser driven compression are discussed. Laser beam filamentation and plasma jetting were studied at various laser wavelengths (λ = 1.05 µm, 0.53 µm and 0.35 µm) using optical probing techniques. To investigate the I and λ scaling of thermal smoothing processes microdiscs were irradiated with a spatially modulated incident beam at 1.05 µm and 0.53 µm. The observations were compared with predictions of a two dimensional hydrodynamic code and showed good agreement. Ablation pressure measurements on layered targets were carried out at several laser wavelengths (λ = 1.05 µm, 0.53 µm and 0.35 µm) in planar and spherical geometry. The first direct observations of RT instabilities on corrugated discs were made indicating that the growth rate is about 0.3 × classical. Two dimensional simulations showed again good agreement with the experimental observations. Finally compression experiments driven by either six infrared or green beams were carried out and compared with numerical predictions.