The analysis of the interaction between electromagnetic waves and electron beams in semi-infinite wigglers is presented. The beam is assumed to include two cold streams of electrons, hence its space-charge waves may be unstable (“two-stream instability”). In the wiggler, this instability is shown to yield much larger growth rates (up to seven times greater) than in the conventional one-stream free electron laser (FED. Accordingly, the gain per pass is enhanced by orders of magnitude. The enhancement of the two-stream instability is shown to be most effective for short-period wigglers.
Bibliographical noteFunding Information:
Manuscript received September 14, 1989; revised January I I , 1990. This work was partially supported by the fund for the encouragement of research at the Technion, the Israeli Academy of Science and Humanities. and the Bi-National fund. M. Botton is with the Department of Electrical Engineering. Technion-Israel Institute of Technology. Haifa 32000. Israel. A. Ron is with the Department of Physics. Technion-Israel Institute of Technology, Haifa 32000, Israel. IEEE Log Number 9035367.