Speaker
Dr
Ryutaro MINAMI
(Plasma Research Center, University of Tsukuba)
Description
Electron cyclotron heating (ECH) power modulation experiments in GAMMA 10 tandem mirror have been started in order to generate and control the high heat flux and to make the ELM (edge localized mode) like intermittent heat load pattern for divertor simulation studies. ECH for potential formation at plug region (P-ECH) produces electron flow with high energy along the magnetic filed line. Heat flux during ECH injection corresponds to the steady-state heat load of the divertor plate of ITER.
Particularly, in the GAMMA 10 tandem mirror, ECH is recognized as a primary scheme to produce plasma-confining potentials. The P-ECH drives a substantial portion of the heated electrons into the loss cone and induces an intense axial flow of warm electrons, which is observed as end loss electrons. However, the maximum energy density obtained is about 0.05 MJ/m$^2$ [1] and is still far lower than that of ITER ELM.
To achieve the generation of higher heat flux, it is necessary to design a high efficiency mirror antenna. In the present ECH system, the e-folding radius of the power density is 62.5 mm. The development of new mirror anntena has carried out in order to concentrate the heating power on the axis. The e-folding radius of power density of new mirror antenna is 40 mm. It is expected to approach the ITER level energy density is by the upgrade the new mirror antenna with narrower e-folding radius of the power density of radiation distribution.
In this paper, preliminary experimental results in ECH power modulation by using new mirror antenna for control of high intermittent heat flux in GAMMA 10 tandem mirror for the future divertor simulation studies are presented.
[1] R. Minami et al., Fusion Sci. Tech. 68, (2015) 142.
Primary author
Dr
Ryutaro MINAMI
(Plasma Research Center, University of Tsukuba)
Co-authors
Mr
Kohei TSUMURA
(Plasma Research Center, University of Tsukuba)
Mr
Satoshi KAJINO
(Plasma Research Center, University of Tsukuba)
Dr
Tomoharu Numakura
(Plasma Research Center, University of Tsukuba)
Prof.
Tsuyoshi IMAI
(Plasma Research Center, University of Tsukuba)
Dr
Tsuyoshi Kariya
(Plasma Research Center, University of Tsukuba)
Mr
Yoichi ENDO
(Plasma Research Center, University of Tsukuba)
Prof.
Yousuke Nakashima
(Plasma Research Center, University of Tsukuba)
Mr
Yuto EBASHI
(Plasma Research Center, University of Tsukuba)
