Beam-plasma discharge in a dielectric cavity by electron beam injection

We have explored the beam-plasma discharge excited by the injection of a continuous electron beam with energy 1-10 keV and current 10-60 mA into a cylindrical dielectric cavity at a pressure of 1-10 Pa. The plasma density and the electron temperature of the discharge are 1.2-3 times greater than for the plasma formed by electron beam transport in the vacuum chamber without a cavity. We describe a model in which there is an additional inflow of energy into the discharge from secondary electrons emitted from the cavity surface by beam electrons and from plasma ions accelerated in the near-wall sheath. We show that this discharge can be used for efficient ion etching of the inner surface of dielectric vessels.