28 GHz 10 kW gyrotron system for electron cyclotron resonance ion source

The 28 GHz gyrotron system (GS) has been purposely designed to meet present-day demand for a microwave source for powering an electron cyclotron resonance ion source capable of producing both high total current and high average ion charge. A gyrotron oscillator of GS operates in both continuous wave and pulse regimes with the output microwave power smoothly regulated in the (0.1–10) kW range. As a whole the functional structure of GS follows the general method of design for feedback controlled microwave sources. The fast feedback loop consists of microwave power detector unit, a purposely developed PC control system, and a high voltage power supply, the regulated voltage from which controls the gyrotron output power. The feedback characteristic time is less than 1 s. The accuracy of a pre-set microwave power maintenance in continuous wave operation of GS is better than 100 W at an output power of 10 kW, and about 50 W at a power of 1 kW. In pulse operation the pulse length can be varied in the range of (1...