Growth and decay of macroparticles: A feasible approach to clean vacuum arc plasmas

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.365731· OSTI ID:773633

Anders, A ^[1]

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1. LBNL Library

Metal and carbon plasmas produced at nonstationary cathode spots are inherently contaminated with micron-size macroparticles, and their removal is typically done by guiding the plasma through curved magnetic macroparticle filters in order to spatially separate plasma and macroparticles. In this article, a possible alternative approach is discussed in which macroparticles are destroyed rather than removed. Mass and energy transfer from the plasma to macroparticles are considered. Both cold and warm ion approximations are discussed. It was found that the desired result--complete evaporation of macroparticles before arrival at the substrate--cannot be easily achieved in any case. Ion bombardment heating is reduced by thermionic electron emission when the macroparticle approaches the temperature region of strong evaporation. The heat loss mechanisms, thermal radiation and evaporation, increase strongly with temperature. Direct heating of the macroparticle seems to be most promising. Microwave heating was ruled out because of the plasma shielding effect. The use of infrared lasers has been proposed, but this solution is likely to be uneconomical.

• Research Organization: Lawrence Berkeley National Lab., CA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 773633
• Report Number(s): LBNL--40122
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 82; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DECAY
ELECTRON EMISSION
ENERGY TRANSFER
MICROWAVE HEATING
THERMAL RADIATION