Two-dimensional Thomson scattering diagnostics of a pulsed discharge produced at around atmospheric pressure

摘要

Laser Thomson scattering (LTS) method has been applied to measure two dimensional distributions of electron density (n_e) and electron temperature (T_e) of a pulsed discharge in neon gas at a pressure of 400 Torr. Such a discharge was produced with good reproducibility by using a set of electrodes composed of a needle and a hemisphere with a gap of 500 μm. The values of electron density and temperature at t=25 ns after the start of the discharge and at the center of the discharge were evaluated to be 4.6×10~(22) m~(-3) and 1.0 eV, respectively. Based on the observed signal intensity and noise components, SN ratios were examined and the way to apply present diagnostic system to the discharge plasma with an electron density as low as 10~(18) m~(-3) was discussed.