A 2-MW, 170-GHz Coaxial Cavity Gyrotron

Abstract

Today's performance requirements for future DEMO gyrotrons are an operating frequency between 170 GHz up to 240 GHz and an output power of significantly larger than 1 MW (today's target: 2 MW). A total gyrotron efficiency of better than 60 % must be achieved. Multi-purpose/multi-frequency operation and frequency step-tunability are required also. It has been shown earlier, that the coaxial-cavity technology is a promising candidate [1]. In [2] a world record RF output power of 2.2 MW has been reported for short-pulses (in the range of few milliseconds). Nevertheless, it has to be proven that the coaxial-cavity technology can be used for long-pulse operation. That shall be achieved by upgrading the existing 2 MW 170 GHz short-pulse prototype used for the demonstration of the 2.2 MW record power. Additionally, a new Inverse Magnetron Injection Gun (IMIG) shall allow a significant larger emitter radius and therefore increased output power at operating frequencies significantly above 200 GHz by keeping the same or even smaller diameter of the warm bore hole of the superconducting gyrotron magnet. Both, the IMIG as well as the longer pulse gyro-tron will show the way towards higher output power at higher operating frequencies of gyrotrons together with a more robust design and construction of that kind of tubes.

Singular and Hypersingular Integral Equations Techniques for Gyrotron Coaxial Resonators with a Corrugated Insert

“…In particular we have studied 2-MW, 170-GHz coaxial cavity gyrotron which was developed in FZK and described in [10]. Operating mode of this gyrotron is TE 34,19 .…”

“…we can calculate F m (w) function which is a solution of the resulting HSIE (10). From its definition follows that this function equals E z considered on Σ within the constant factor.…”

Large Scale CW ECRH Systems: Some considerations

“…Prototypes of the ITER-gyrotrons were successfully developed in Japan and Russia [5,6]. In EU a more ambitious R&D aims at 2 MW power per unit [7]. The development of the W7-X gyrotrons was launched in 1998 in EU (THALES) and US (CPI).…”

Cold testing of quasi-optical mode converters using a generator for non-rotating high-order gyrotron modes

“…[6][7][8][9][10] The gyrotron consists of several major components including a magnetron injection gun (MIG), open-ended cavity, mode converter, and collector. [11][12][13] The mode converter is critical: it converts a higher-order mode from the interaction circuit into a Gaussian-like beam, which effectively transmits RF power through free space. [14][15][16] Typically, a quasi-optical mode converter (QOMC) comprises an open-ended, non-symmetrical waveguide launcher and a series of quasi-parabolic mirrors, which are situated directly after the gyrotron's interaction circuit.…”