Cross-field flow of plasma produced by electron beam evaporation

The gadolinium atomic beam produced by electron beam heating contains a weakly ionized plasma, whose electron temperature is lower than 0.1 eV, and drift velocity is about 1200 m/s. The plasma of the ion density of 1-10x108 cm-3 was led to a magnetic field of 0 - ±1.5 kG between iron cores. The ion saturation currents were measured with the ion collectors set in the magnetic field. When the magnetic field was applied, the instability appeared in the ion saturation current. With increasing the magnetic field, the ions detected by the ion collectors decreased and no ions were detected at all. The magnetic field intensity at which the plasma does not flow and ions are not detected does not depend on plasma density. This means that for the cross-field flow of the plasma to occur, the potential energy of the electric field must be less than the ion kinetic energy, that is, Larmor radius of ions are two times larger than plasma width. In addition, it is found that the plasma contained in the atomic beam can be removed by the magnetic field. (author)