Recent progress of divertor simulation research using the GAMMA 10/PDX tandem mirror. (9th August 2017)

• Record Type: Journal Article
• Authors: Nakashima, Y.; Ichimura, K.; Islam, M.S.; Sakamoto, M.; Ezumi, N.; Hirata, M.; Ichimura, M.; Ikezoe, R.; Imai, T.; Kariya, T.; Katanuma, I.; Kohagura, J.; Minami, R.; Numakura, T.; Yoshikawa, M.; Iijima, T.; Islam, M.M.; Nojiri, K.; Shimizu, K.; Terakado, A.; Togo, S.; Asakura, N.; Fukumoto, M.; Hatayama, A.; Hirooka, Y.; Kado, S.; Kubo, H.; Masuzaki, S.; Matsuura, H.; Nakano, T.; Nagata, S.; Nishino, N.; Ohno, N.; Sagara, A.; Sawada, K.; Shoji, M.; Tonegawa, A.; Ueda, Y.;
• Is Part Of: Nuclear fusion. Volume 57:Number 11(2017:Nov.)
• Publication Date: 2017-08-09
• Subjects: divertor simulation -- tandem mirror -- plasma detachment -- GAMMA 10/PDX; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/aa7cb4
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: This paper describes the recent progress in divertor simulation research using the GAMMA 10/PDX tandem mirror towards the development of divertors in fusion reactors. During a plasma flow generation experiment in the end cell of the GAMMA 10/PDX, ICRF heating in the anchor cell successfully extended the particle flux up to 3.3 × 10 23 m 2 s −1 . Superimposing the short pulse of the ECH also attained a maximum heat flux of ~30 MW m −2 . We have succeeded in achieving and characterizing the detachment of the high-temperature plasma, which is equivalent to the SOL plasma of tokamaks, by using the divertor simulation experimental module (D-module) in the GAMMA 10/PDX end cell, in spite of using a linear device with a short magnetic field line connection length. Various gases (Ar, Xe, Ne and N2 ) are examined to evaluate the effect of radiation cooling against the plasma flow at the MW m −2 level in the divertor simulation region and the following results are obtained: (i) Xe gas was most effective in the reduction of heat and particle fluxes (1%, 3%, respectively) and has a stronger effect on electron cooling (down to ~1.6 eV) in the used gas species. (ii) Ne gas was less effective. On the other hand, (iii) N2 gas showed more favorable effects than Ar in the lower pressure range. These results will contribute to the progress in detached plasma operation and in clarifying the radiation cooling mechanism towards the development of future divertors.