ION-ACOUSTIC-WAVE PUMPED FREE-ELECTRON LASER

In this paper, the problem of free electron laser excitation by a rela tivistic electron beam passing through background plasma with ion acou stic wave as wiggler is studied. Under the case of Compton and Raman r egime, both the linear dispersion relation and the growth, are present ed. The analysis makes no assumption on the relative relation of the b eam density and the background plasma electron density, and the result is also lit to bath ion ripple laser case and the large amplitude ion acoustic wave case.