Date of Award


Publication Type

Doctoral Thesis

Degree Name



Electrical and Computer Engineering


Engineering, Electronics and Electrical.




Uniform field steady state ionization growth currents are measured in SF(,6), N(,2) and SF(,6) + N(,2) mixtures over the E/p range 60-450 V cm('-1) Torr('-1). Analysis of ionization growth currents provided quantitative data on effective ionization, ionization and attachment coefficients. The variation of effective ionization coefficient in SF(,6) + N(,2) mixtures is found to be nonlinear with the percentage mixture ratio. It is observed that at a given electric field to gas pressure ratio, the effective ionization coefficient decreases with increasing SF(,6) component in the mixture. This reduction in the effective ionization coefficient becomes relatively higher as E/p decreases. However, once a certain concentration of SF(,6) in the mixture is reached, further addition of SF(,6) responds with relatively little effect on the reduction. The same behaviour is observed for spark over voltage measurements. Variation of spark over voltage with SF(,6) concentration shows saturation tendency particularly at high pd (cm-torr) levels. The data for effective ionization, ionization and attachment coefficients is also obtained in CCl(,2)F(,2) + CO(,2) electronegative gas mixtures where it is again observed that the variation of the effective ionization coefficient with respect to mixture percentage ratio is nonlinear at a given E/p in the interval 100 (LESSTHEQ) E/p (LESSTHEQ) 180 V cm('-1) torr('-1). A Monte-Carlo simulation technique is used to provide swarm data in SF(,6). The swarm parameters evaluated are compared with the experimental values of drift velocity, ratio of radial diffusion coefficient to mobility, ionization and attachment coefficients available in the literature. The electron-molecule collision cross sections adopted in the simulation resulted in good agreement with the experimental values over the E/p range of interest 100 (LESSTHEQ) E/p (LESSTHEQ) 180 V cm('-1) Torr('-1). The simulation is also extended to EXB uniform fields to observe the effect of perpendicularly applied magnetic fields on the swarm parameters of SF(,6).Dept. of Electrical and Computer Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1985 .D553. Source: Dissertation Abstracts International, Volume: 46-08, Section: B, page: 2753. Thesis (Ph.D.)--University of Windsor (Canada), 1985.