Measurement of preheating due to radiation and nonlocal electron heat transport in laser-irradiated targets.

This paper reports an experimental study on preheating of laser-irradiated targets. We performed temperature measurements at the rear surface of laser-irradiated targets under conditions of two different laser wavelengths (0.35 or 0.53 μm) and several intensities (2×1013–1×1014 W/cm2) in order to verify an effect of radiation and nonlocal electron heat transport. The preheating temperature was evaluated by observing self-emission, reflectivity, and expansion velocity at the rear surface of planar polyimide foils. The experimental results show that the x-ray radiation is dominant for preheating for 0.35-μm laser irradiation, but contribution of nonlocal electron heat transport is not negligible for 0.53-μm laser irradiation conditions. [ABSTRACT FROM AUTHOR]