Studies of Cold Cathode Discharges in Magnetic Fields

Abstract

Some experimental studies of a cold cathode discharge in a strong magnetic field are described. Current densities of the order of half an ampere per square centimeter in various gases were used. For such a discharge, the current to the cathodes is about 75% ionic. Positive ions leaving the discharge by moving across the magnetic field were observed with a mass spectrometer and showed a temperature of about 1 v. Fast electrons from the cathode escape from the discharge across the magnetic field without losing the greater part of their energy. By considering the rate of ion production it is shown that the slow electrons in the discharge have a temperature less than about three volts. Fluctuations in charge densities must play a very important role in the mechanism of the discharge.