Breakdown in high frequency electrodeless discharge at low pressure in the presence of a steady transverse magnetic field

Abstract

A theoretical investigation has been made of the problem of electrical breakdown in a high frequency electrodeless discharge at low pressure in the presence of a steady transverse magnetic field following the method of von Engel et al. for similar discharge without such a field. Curves giving the breakdown field as a function of wavelength with α, the ratio of the cyclotron frequency to the frequency of the applied field, have been drawn. It is shown that with increase in α the breakdown field tends to increase and the main region of the curve displaced towards longer wavelengths. The increase in breakdown field with a given change in α is found to be more pronounced with the higher order modes of discharge. The effect of angle of arrival at the end walls of the charged carriers on the breakdown mechanism has also been considered. Results indicate that the effect should counteract appreciably the aforesaid tendency of the breakdown field to increase in the presence of a magnetic field. The so-called cut-off values of wavelengths have also been computed. It is shown that the cut-off value increases with increase in α, and in contrast to the situation in the absence of a magnetic field, might define either a long or short wavelength limit of discharge depending upon the value of α.