Time-resolved two-dimensional measurements of the electron density, electron temperature, and drift velocity of laser-produced carbon plasmas using the ion feature of collective laser Thomson scattering

Abstract

Abstract Temporal evolutions of two-dimensional (2D) plasma profiles produced by Nd:YAG laser ( 5.9 × 10 9 W cm − 2 , 8 ns FWHM) were investigated at 5–25 ns after the laser peak at 0.2–0.5 mm from the initial target surface by measuring the electron density (n e), temperature (T e), and drift velocity (V d). The T e profiles were nonuniform and showed a peak at 0.3 to 0.4 mm above the target surface. The high-temperature region of the plasma moved outward at the same speed as that of the expansion of the plasma, indicating the isothermal expansion ends immediately after the ablation pulse. The 2D profiles of V d and pressure also show that the plasma expanded anisotropically.