Cyclotron autoresonance masers: Recent experiments and projects

The cyclotron autoresonance maser (CARM) [1–3] is one of the promising modifications of free-electron masers (FEM) operated at the millimeter and submillimeter waves. In this range CARM requires particle energies significantly lower than for the ubitron, and magnetic fields smaller than those for the gyrotron. The CARM is considered as a possible source of coherent millimeter wavelength radiation with large average (continuous) power for plasma heating in controlled fusion devices.