Plasma heating by collisional magnetic pumping in a modified penning discharge.

Collisional magnetic pumping as a plasma heating method in a modified Penning discharge set up as a magnetic mirror configuration was experimentally investigated. The heating rate as a function of rf driving circuit frequency, rf maximum exciter coil current, Penning discharge current, and background steady-state confining magnetic field was experimentally verified according to the heating rate equation. The Penning discharge electrode and magnetic field arrangement resulted in the formation of two electron populations in a helium plasma. It was found that the primary electrons were heated more than the secondary electrons. More importantly, it was found that these four parameters had a functional dependence consistent with the heating rate equation in most cases, although the magnitude of the heating was as much as 100 times more than theoretically predicted.