Speaker
Dr
Ryuya Ikezoe
(Plasma Research Center, University of Tsukuba)
Description
In the GAMMA10/PDX tandem mirror, divertor simulation experiments are carried out in the west end region. In order to control end loss ions, ion cyclotron range of frequency (ICRF) waves are used. In previous experiments, we achieved two-times increases of the particle flux ($1.7×10^{23}m^{-2}s^{-1}$) while the parallel ion temperature was 100eV at the end region during ICRF heating in the central cell and the anchor cell. In order to further increase of the particle flux and the ion temperature at the end region, we tried ICRF heating with double half turn (DHT) antenna in the plug barrier cell, next to the end region. DHT antenna has been installed in the west plug/barrier cell.
Firstly, DHT antenna was driven with a frequency of 7.7MHz that is the ion cyclotron frequency near the center of the plug/barrier cell. The line density in the plug/barrier cell increased remarkably and the parallel ion temperature at the end region increased also during the ICRF heating. However, the ion flux from the central cell decreased due to the trapping in the plug/barrier cell. With additional gas injection in the plug/barrier cell, increase of the ion flux was observed. In this case, no increase of the parallel ion temperature was observed.
Secondary, we injected ICRF wave with the frequency of 7.2MHz that has no resonance layer in the plug/barrier cell. This wave can propagate to the end region and heat end loss ions. In this experiment, we observed the increase of both the ion flux and the parallel ion temperature at the end region with additional gas injection. For further increase of the particle flux at the end region we will replace the DHT antenna with Nagoya Type-III antenna that is used for the plasma production in the central cell.
Primary author
Mr
Seowon Jang
(Plasma Research Center, University of Tsukuba)
Co-authors
Mr
Junpei Itagaki
(Plasma Research Center, University of Tsukuba)
Dr
Mafumi Hirata
(Plasma Research Center, University of Tsukuba)
Dr
Makoto Ichimura
(Plasma Research Center, University of Tsukuba)
Prof.
Mizuki Sakamoto
(Plasma Research Center, University of Tsukuba)
Dr
Ryuya Ikezoe
(Plasma Research Center, University of Tsukuba)
Mr
Shuhei Sumida
(Plasma Research Center, University of Tsukuba)
Prof.
Yousuke Nakashima
(Plasma Research Center, University of Tsukuba)
