Hollow cathode discharge: arc regime with interior positive column in argon flow
Plasma generated in the cathode is dealt with. The device used comprises a cathode and an anode with a central orifice through which the plasma is ejected. The anode is placed at the cathode outlet. The study of argon flow inside the cathode emphasized the presence of a sonic flow in the cathode outlet section. Assuming the gas temperature equal to that of the wall, the pressure distribution inside the cathode was determined. The plasma characteristics were measured with electrostatic probes; electron densities reached 10 to the 14th power electrons/cu m, electron temperatures were 1 to 2 eV, and plasma potentials were close to the anode potential, the major part of the discharge voltage being concentrated within the cathode sheath. The influence of the cathode material on the discharge characteristics was emphasized. The use of materials whose electronic emission is greater than that of refractory metals of current use permits one to lower the cathode temperature as well as the discharge voltage. With LaB6 cathodes it has been possible to operate the discharge with a total voltage lower than the argon ionization potential, which is explained by a two-step ionization process with a metastable level in-between. (GRA)
- Research Organization:
- Office National d'Etudes et de Recherches Aerospatiales (ONERA), 75 - Paris (France)
- OSTI ID:
- 7233559
- Report Number(s):
- N-76-16943; ONERA-NT-1975-3
- Resource Relation:
- Other Information: Report Will Also Be Announced as Translation. Thesis. Submitted to Univ., Paris
- Country of Publication:
- United States
- Language:
- English
Similar Records
The plasma properties and electron emission characteristics of near-zero differential resistance of hollow cathode-based plasma contactors with a discharge chamber
Dynamic thermal behavior of polycrystalline LaB 6 hollow cathodes