Development in Russia of Megawatt Power Gyrotrons for Fusion

Abstract

Tests of the Russian ITER gyrotrons were continued after debugging of the test facility at Kurchatov Institute including the evacuated transmission line and power supplies capable to provide gyrotron CW operation. A new ITER gyrotron (V-10) with upgraded body insulation, liquid cooling system for the DC-break ceramic and improved design of the relief window has been manufactured and is currently under test. A maximal total efficiency near 55% at 1 MW power level was attained. The maximal pulse duration of 1000 s at 0.8 MW power was limited at that time by the test stand. At 1 MW power level the gyrotron V-10 up to now reached a pulse duration of 570 s. An advanced short-pulse (100 ms) gyrotron model operating in the TE 28.12 mode demonstrated a very robust operation at relatively high electron energies (up to 100 keV) necessary to achieve 1.5-2 MW output power. Three double frequency gyrotrons have been delivered to ASDEX Upgrade. The development of a multi-frequency gyrotron with a broadband or tuneable synthetic diamond window is in progress.

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].…”

“…They are also transparent at 105 GHz corresponding to 3λ/2 [10], and 175 GHz at 5 λ/2. A possible set of modes, which are compatible with a generic cavity design is TE22,6 (104 GHz), TE28.8 (140 GHz), and TE34,10 (174 GHz) [10,11], or TE17,6 (104.7 GHz) and TE22,8 (140 GHz) as built from GYCOM for AUG [6]. The development of a 2f gyrotron at JAEA is based on TE31,11 (170 GHz) and TE25.9 (137 GHz), both frequencies match the resonances of a single disk window with 1.853 mm thickness [12].…”

Test bench for ITER gyrotrons. Measurements of the RF power value during tests of the ITER-prototype gyrotrons

“…The calculated amounts of heat loads in the regime of real time were derived on the screen of monitor and archived. For illustration the temporal behavior of the average heat powers, absorbed in the collector, resonator and terminal load, calculated according to formula (1), and also of average total heat power during the gyrotron Vesuvius-9 tests is given in Fig. 7.…”

Diplexers for Power Combination and Switching in High Power ECRH Systems

“…Such gyrotrons are under development in Russia [21] and Japan [16]. In EU a more ambitious R&D program was launched aiming at 2 MW power per gyrotron [22].…”