Date of Award
Master of Science
Dennis Keefer, Kenneth Kimble
A circuit model for an inductively coupled RF plasma generator was developed. This analysis is restricted to a cylindrical geometry with a solenoid driving coil. The system modeled assumes a cylindrical chamber filled with partially ionized argon gas. The circuit model was developed for temperatures from 1000 to 20000K and pressures from 1 to 760 Torr. The plasma was modeled as an inductor of cylindrical geometry magnetically coupled to the driving solenoid coil with a load resistance. The circuit parameters modeled are the coil and plasma inductance, coil and plasma resistance, and coupling of the plasma to the coil. The inductance, resistance, and coupling are dependent on the conductivity of the plasma and the dimensions of the plasma generator. The coupling and inductance were calculated using standard formulas. The resistance, length, and the radius of the plasma were calculated using techniques developed in this thesis. Three example configurations were analyzed: an estimated model of a low pressure plasma generator with a long solenoid and loose coupling, a single short solenoid with stronger coupling, and two coaxial short solenoids separated by the length of the radius with its respective coupling coefficients. The results are plots of each circuit parameter as a function of temperature of the plasma. We can conclude that the results demonstrate the mechanics behind the E to H mode transition.
Waivio, Nathan A., "A circuit model of an inductive plasma generator. " Master's Thesis, University of Tennessee, 2000.