Plasma and Fusion Research
Online ISSN : 1880-6821
Regular Articles
Development of High Power Gyrotron and Power Modulation Technique using the JT-60U ECRF System
Takayuki KOBAYASHIMasayuki TERAKADOFumiaki SATOKenji YOKOKURAMitsugu SHIMONOKoichi HASEGAWAMasayuki SAWAHATASadaaki SUZUKIShinichi HIRANAIKoichi IGARASHIKenji WADATakashi SUZUKIKen KAJIWARAAtsushi KASUGAIKeishi SAKAMOTOAkihiko ISAYAMAGo MATSUNAGAShinichi MORIYAMA
Author information
JOURNALS FREE ACCESS

2009 Volume 4 Pages 037

Details
Abstract

Electron cyclotron range of frequency system of the JT-60U finished operation at the end of August 2008, and improvements toward JT-60SA have been started. In the last two years stable gyrotron oscillation at an output power of 1.5 MW for 1 s was demonstrated, for the first time, using the 110 GHz gyrotron. It was verified that the heat load on the cavity was at an acceptable level with continuous oscillations at 1.5 MW. The absorption power of the collector was also at an acceptable level for the longer pulse oscillation of 5 s. A power modulation technique based on anode voltage modulation was also developed in order to study the effects of modulated Electron Cyclotron Current Drive (ECCD) on Neoclassical Tearing Mode (NTM) stabilization. Modulation frequencies of up to 7 kHz were achieved at output power of 0.8 MW exceeding the previous limit of 3 kHz. Modulated ECCD experiments in synchronization with the NTM were successfully performed with a modulation frequency of around 5 kHz. Development of an accurate synchronization system played an essential role in the experiments that needed a maintained phase between the magnetic probe signal and modulated ECCD in real time. The results provide significant information for further developments that will enhance the overall performance of ECRF systems in the near future.

Information related to the author
© 2009 by The Japan Society of Plasma Science and Nuclear Fusion Research
Previous article Next article
feedback
Top