60-GHz gyrotron development program alternate frequency study

The purpose of this study was to take a preliminary look at what the considerations are when scaling the frequency of a gyrotron oscillator a few percent from an existing design. To minimize construction costs, it would be most advantageous to keep all parts the same and operate only with slightly different voltages and magnetic fields. There are two tube parts that must be changed for any frequency modification: the tube output window and the oscillation cavity. This study assumed that the output window and the cavity would be scaled in dimensions for best operation at the new frequency. The main thrust of the study was to examine the feasibility of using the 60 GHz gun (K-8060) and magnet (VYW-8060) for operation at 56 and 52 GHz, and the 28 GHz gun (K-8000) and magnet (VYW-8000) for operation at 26 and 30 GHz. All work was done using Varian computer gun codes and hand calculations. It must be mentioned that these results are only a guideline and that a final design would need some further fine tuning.