Diagnostics of plasma electron density and collision frequency of fluorescent lamp using microwave transmission diagnostics

Abstract

Abstract According to the propagation characteristics of the microwave in the plasma, the collision frequency and electron density in the plasma can be simultaneously obtained by measuring the attenuation and phase shift. A new method is proposed to diagnose the plasma in the T8 and T4 fluorescent lamps. According to the experimental results, the electron density of the T8 and T4 fluorescent lamps range from 0.8 × 1011/cm 3 to 5.3 × 1011/cm 3 and 1.4 × 1011/cm 3 to 8.1 × 1011/cm 3 respectively. Besides, the collision frequency of T8 and T4 are (2 − 7) × 1010Hz and (2.9 − 7.4) × 1010Hz respectively. This is basically consistent with the diagnostics results of the two-probe diagnostic method. Moreover, the S-parameters simulation results using the measured plasma parameters based on the Drude’s model are also consistent with the experimental results.