Plasma Heating by Lower-Hybrid Parametric Instability Pumped by an Electron Beam

Abstract

We study experimentally the interaction of an electron beam modulated near the lower-hybrid frequency with a longitudinally magnetized inhomogeneous plasma. At high levels of beam modulation above a certain threshold, the beam pumps the parametric decay instability into the lower-hybrid wave and ion-acoustic wave, and correspondingly plasma heating takes place rapidly. The instability threshold is determined in a parameter space. These results are compared with theory, and reasonable agreement is obtained.