| High frequency plasma chemical vapor deposition (PCVD) was proved a good method as a clean ambience with high temperature thermal resource which used in synthesizing high pure silica glass.In the case that the equipment ran stably for a long time, it was obtained that the range of the anode voltage was stable between 10. 5~11. 5KV, the flux of protective oxygen was between 8~10Nm3/h, and the flux of working oxygen was between 3~5Nm3/h. And on such condition the temperature field of the plasma tag end was stable.According to the growth and coacervation kinetics of the liquid drop, deposition of the particle was divided into three steps: chemical reaction, nucleation period, conglutinating and growing period. Utilizing the thermodynamics data, chemical equilibrium equation and the chemical kinetics theory, it could be concluded that the chemical reactions in the temperature field of the plasma were rapid and the reactions were accomplished fully in a short time.The high pure silica glass had the characters of low hydroxyl guoup(OH) content and spectrum trasmittion high optical homogeneity, with excellent spectral transmittance. |
