Ion Energies in a Cold Cathode Discharge in a Magnetic Field

A cold cathode discharge in a strong magnetic field was studied by means of a pulsing technique. The discharge was run at pressures of a few microns with magnetic fields of 2400 gauss and currents of the order of half an ampere. By means of a multivibrator and amplifier the discharge was pulsed off for 300 μsec at 1000 μsec intervals. During the off period the current flow to the cathodes was observed. Analysis of the current flow shows an approximately Maxwellian distribution of velocities at the cathodes with a temperature of about 0.5 ev. This gives an ion density in the discharge of approximately 20%.