Observation of Drift Motion of a Collisional Plasma in Cross Fields

Abstract

The drift velocity of particles in a plasma cylinder immersed in an axial magnetic field and a radial electric field was investigated using a test-wave technique, and plasma parameter measurements were made using a Langmuir probe. The drift velocity is determined directly by the test wave method, and at the same time, calculated from the information concerning the electric and magnetic fields, taking into account the effects of a cylindrical geometry and a finite Larmor radius. From the discrepancy between these two drift velocities, the collision term for a cylindrical geometry can be determined as a function of B. Finally, after making some corrections in E_r, the value of the cross section for collision between ions and neutrals is obtained, which is smaller than the current values in the literature. After some discussion, it is found that a simple estimation of the slowing-down cross section is in good agreement with the experiment.