Measurement of an Electron Density Disturbance in a Positive Column with Magnetic Field

Abstract

It is found that two columns of different luminosity which are separated by an intervened disc appear along a magnetic field, when a certain disc is inserted in a positive column with an axial magnetic field. These are a luminous column and a dark column which are extended from the disc toward the cathode and the anode side respectively. These deviations in luminosity decay from it in the direction of each side. Change in luminosity along the axis is confirmed by measurements of electron density distribution with movable probes. An attempt to attribute this recovery toward the normal distribution to ambipolar diffusion of charged particles across the magnetic field is given.