ELECTROCHEMICAL PROPERTIES OF SEEDED PLASMA FLOW FIELDS II
Abstract
The effectiveness of various electronegative gases (O2, CO2, NO, SF6, H2O), as a means of reducing the ionization in plasma flow fields (nitrogen plasma) are experimentally investigated and compared. In the thermal condition prevailing, SF6 and water vapor are found to be the most effective in quenching the plasma. Electrostatic probe, optical emission spectroscopy, thermocouple and N0 titration techniques are employed to monitor the plasma properties. The complex nature of the short duration pink afterglow in nitrogen is studied in some detail both in flowing and non-flowing systems in order to ascertain more quantitatively the effectiveness of the different quenching gases. The effects of gas pressure, wall condition and gas purity on the afterglow behaviour are closely examined in view of the reproducibility of measurements. A theoretical study of the limitations and applicability of electrostatic probe methods to plasmas containing negative ions is made and computations of characteristics are presented. Results of measurements of the flow velocity by different techniques are compared and the importance of an accurate determination of plasma flow field velocity is discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1965
- Accession Number
- AD0632352
Entities
People
- A. I. Carswell
- Ashish Ghosh
- C. Richard