High-Power CARM research at the MIT Plasma Fusion Center is described. The experimental results on a Ka-band, long-pulse CARM oscillator experiment are presented. In this experiment, a SLAC 5045 klystron gun produced an electron beam at 250-320 kV and 10-20 A; a beam α ≡p⊥/p||, variable from 0 to 1, was produced on this electron beam with a wiggler magnetic field near guide field resonance. CARM operation was observed for many parameter settings, and for frequencies ranging from 29 to 32 GHz. Output powers as high as 100 kW were achieved with an efficiency of up to 3%. Higher frequency radiation near 74 GHz was also obtained and is attributed to second harmonic CARM operation. The design of a 17 GHz CARM amplifier for application as an RF accelerator driver is presented.
B. G. Danly, B. G. Danly,
"High-power CARM experiments", Proc. SPIE 1514, 15th International Conference on Infrared and Millimeter Waves, 151464 (1 December 1990); doi: 10.1117/12.2301630; https://doi.org/10.1117/12.2301630