Development of 170 GHz/ 1MW/ 50%/ CW gyrotron for ITER

Abstract

Recent test results of 170 GHdIMW/CW gyrotron being developed in Russia within the ITER program are presented. At pulse duration of 0.1 s, power of 1.15 MW in the output Gaussian beam was attained. In the experiments on pulse extension, output power was not so large considering performance capabilities of high voltage source. At output power of 0.85-0.9MW, the gyrotron pulse could be extended to nearly 20 s. At the power reduced to 0.7MW, pulse lasted up to

Design of transverse magnetic field sweeping solenoids for 140 GHz mega‐watt gyrotrons

“…With the increase of the pulse width, this problem will become more and more serious. To ensure a stable output in CW operation, in some studies, a vertical magnetic field solenoid with a periodical changing axial magnetic field has been applied for sweeping the electron beam up and down in the collector [11–15]. There are two disadvantages in this method: (i) By changing the axial magnetic field, only the bombardment position of the electron beam moves. (ii) Since the collector is relatively large, the changing frequency of the axial magnetic field is restricted in the range of 5–10 Hz, in order to avoid an excessive eddy current on the surface of the collector.…”

Recent Results in the Development of 170 GHz/CW Gyrotrons for ITER

“…During long-pulse test of previous 170GHz/1MW gyrotron versions heating of DC break ceramic insulator and relief window was found to be potentially dangerous [1]. This heating was caused by relatively high level of stray radiation resulted from usage of simple quasioptical (QO) converter.…”

A New Efficient Mirror Cooling for the Transmission Line of Fusion Reactor ECH Systems Based on Triply Periodic Minimal Surfaces

“…plasma by means of 32-MW-class gyrotrons [7] operating at 170 GHz (as those foreseen for ITER [8], [9], [10], [11]), long quasi-optical transmission lines enclosed in pipes under vacuum [12], and front-steering antennae composed of identical modular units of two mirrors [13]. The gyrotrons are grouped in four clusters of eight sources each: the power of a cluster is transmitted by a quasi-optical evacuated multibeam transmission line [14] up to two launchers in the DTT equatorial and upper ports, where the beams are launched into the plasma by independently steerable mirror antennas.…”