Characteristics of plasma source for the plasma polishing of super smooth optics

RF excited capacitive coupled hollow cathode (CCHC) plasma source was developed for the fabrication of super smooth optics. The frequency of the RF power was 100 MHz, and the maximum power output was 150W. Optical emission spectroscopy (OES) was used to diagnose the argon plasma generated in the plasma polishing apparatus. Bispectral analysis was used to calculate the argon plasma temperature and electron density. The result shows that when the RF power changed from 40W to 120W the plasma temperature was between 1989K and 2200K. The electron density increased with the increment of the RF power.