ELECTRON-DIFFUSION IN A NONUNIFORM ELECTRIC-FIELD AND A UNIFORM MAGNETIC-FIELD

A Monte Carlo simulation technique has been used to model the electron transport behavior, especially the electron diffusion motion, in the cathode fall region of a glow discharge under the influence of a non-u niform electric field and a transverse magnetic field perpendicular to the cathode sheath electric held. Three types of collisions (elastic, excitation and ionization) are taken into account in our model. The e lectron free flying time is determined by the electron-neutral atom co llision frequency. We focus attention on the electron diffusion distan ce and velocity. The electron-neutral atom collision processes and the electron drift velocity are also studied. The results indicate that w ith the increase of the magnetic field the electron diffusion distance increases and the electron diffusion velocity decreases. The results also show that the collision processes are enhanced by the magnetic he ld, this is in agreement with the experimental result. However, the ax ial magnetic field does not affect the electron transport behavior.