Calculation of nonconverting taper structure for TE/sub 01/ modes in gyrotron
Calculations and analysis of nonconverting taper for circular waveguide with operating TE/sub 01/ mode are presented. Calculations are carried out on the basis of discretely defined T-functions. The results obtained were checked by alternative method of finite elements which is incorporated in widely spread program.
Theoretical evaluation of nonlinear tapers for a high-power gyrotron
The theoretical performance of two nonlinear circular waveguide tapers constructed for a 10-GHz, 30-MW amplifier utilizing the lowest circular electric mode is evaluated. Mode coupling is estimated with a code that solves the generalized telegraphist's equations numerically and is compared with the results of a cascaded scattering matrix code. It is found that assuming a sufficiently lossy conducting boundary allows evaluation of modes that pass through cutoff and that consideration of backward modes usually results in small changes in the forward modes that reconcile the two numerical procedures. A comparison of the raised cosine profile with other taper shapes is made. It is shown that, under some conditions, a raised cosine profile yields less mode conversion than the modified Dolph-Chebyshev profile. >
Operating characteristics of a high power X-band gyroklystron
At the University of Maryland we have designed1) and are operating a high power two-cavity TE01 gyroklystron in the 9.7-10.0 GHz range. The target beam power is derived from a 500 kV beam with a current ranging from 120-240 A in 1 μs pulses. The target microwave parameters for this tube include a power level of 15-30 MW with a gain of 25-30 dB. In this paper we describe the initial characterization of the electron gun performance and detail preliminary microwave amplifier experiments. We also discuss modifications recently made to the two cavity circuit to improve stability.