Low-Voltage Cyclotron Resonance Maser

The gyrotron, which is the most powerful cyclotron resonance maser (CRM), is an extremely effective device to generate high-power microwave radiation. It is used in microwave heating of thermonuclear plasma, radar, and other industrial applications. However, the gyrotron has one basic problem. It requires relativistic (very high energy) electrons. These require very high voltages to produce, and, in turn, relativistic electrons produce intense and dangerous X-rays in the collector region. In this paper, we discuss an alternate method of operation that does not require high voltages. We have also constructed a low-voltage CRM that operates at 2.2 kV and produces 8 GHz at a magnetic field of 0.3 T. In principle, the device should operate at even lower voltages.