Experimental results and technical requirements for a 2 MW, CW, 170 GHz coaxial cavity gyrotron

In recent experiments on a 165 GHz, coaxial cavity gyrotron, the data basis necessary for a technical design and for industrial manufacturing of such a tube has been completed. In particular, the following investigations have been performed: measurement of the amount of microwave stray radiation captured in the mirror box and of the losses at the coaxial insert with improved accuracy; influence of misalignment of the coaxial insert on the gyrotron performance; extension of the microwave pulse length; measurement of the single-mode operating range and of the hysteresis effect due to variation of the beam voltage. The recently obtained results are presented and discussed. The results concerning the hysteresis effect are given in a separate paper at this conference (O. Dumbrajs et al., ibid., paper TH4.2, 2002). Based on these results, the design work for a 2 MW, CW, 170 GHz coaxial cavity gyrotron has started.