Operational Characteristics of the 175-GHz Continuous-Wave Clinotron

The operational characteristics of a watt-level water-cooled 175-GHz continuous-wave (CW) clinotron are studied experimentally and discussed in this article. The oscillator is designed to work either in the broad frequency range (161-175 GHz) and moderate output power (10-200 mW) or in a high-power regime, which has a maximum power of 0.85 W at 174.6 GHz and up to 1.2 W at 171.4 GHz. The radiation power and the frequency can be tuned by changing an acceleration voltage and a beam current. The studies are focused on the long-term drifts of the output power and frequency during a free-running operation of the clinotron. In particular, the influence of a beam current and a cooling water temperature on the frequency is considered and the contribution of both effects is discussed. The maximal variations of a power level and an oscillation frequency observed within 1 h are less than 3 x 10(-2) and 5 x 10(-5) , respectively.