Collisional Mechanism for Producing Electron Cyclotron Echoes from Plasmas

Recent experimental work has established that repeated pulsing, at the electron cyclotron frequency, of a plasma in a slightly inhomogeneous magnetic field results in the stimulation of echo trains. It has been recognized that the production mechanism for these echoes involves some nonlinear process, but those suggested and analyzed previously have not given results agreeing satisfactorily with experiment. In this paper, it is shown that if electron-neutral momentum transfer collisions are taken into account, a suitable nonlinear theory predicting both two-pulse and three-pulse echo characteristics can be developed. Computations based on this theory are presented, and agree well with the published experimental observations.