Investigation of iodine laser interaction of intensities Iλ2 ~ 1013–1015 Wcm–2μm2 with aluminum targets

Abstract

The results of an experimental investigation of iodine laser interaction with Al targets obtained on the laser system PERUN (λ = 1.315 μm, E < 50 J, τ ∼ 350 ps) by means of corpuscular diagnostics, are presented. Ion velocity distributions, angular distributions, and electron temperature were determined. The plasma electron temperature Te ∼ 550 ± 100 eV was weakly dependent on laser intensity in the range Iλ2 ∼ 1014-1015 Wcm-2 μm2. Maximal velocity (energy) for the Al ions was estimated as V ∼ 9 × 107 cm/s (∼ 110 keV) and the maximal measured charge state was z = 13. It was shown that the diameter of the area emitting high energy ions is a few times larger than the focus diameter (80 μm), which indicates a strong influence of lateral heat transport on plasma parameters. The hot electron temperature Te.h was estimated to be in the range 6–10 keV. On the basis of Langmuir probe measurements, the electron temperature of expanded Al plasma at a distance of about 100 cm was estimated to be Te ∼ 3 eV