Variation of EEDF to the radial direction in He DC positive columns
- Nagoya Institute of Technology (Japan)
In an inert gas DC positive column, the charged particles produced in the tube center diffuse to recombine at the tube wall. The ambipolar diffusion theory for a cylindrical discharge tube has deduced the radial plasma density profile of the 0th order Bessel function under assuming that the mean electron energy is uniform over the positive column. The electron energy distribution (EEDF) observed in a Ne positive column, however, is varied to the radial direction, showing a decrease of the mean electron energy to the direction. The EEDF observed in a He column is known to agree with that calculated from the Boltzmann equation, and to be approximated by appropriate two straight lines; the bulk temperature T{sub b} and the tail temperature T{sub t}. An experiment has shown that the decrease of T{sub b} is much larger than that of T{sub t}. The purpose of the present paper is to describe the variation of the EEDF of a He positive column to the radial direction with some theoretical considerations.
- OSTI ID:
- 212810
- Report Number(s):
- CONF-950749--
- Country of Publication:
- United States
- Language:
- English
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