Plasma and Fusion Research

Volume 15, 1201056 (2020)

Rapid Communications

Dependence of Plasma Parameters in Hydrogen Discharges on Magnetic Field Configuration and Neutral Pressure in the DT-ALPHA Device
Tomohiro SEINO, Hiroyuki TAKAHASHI, Peerapat BOONYARITTIPONG, Takeshi SAIKYO, Kenta OGASAWARA, Atsushi OKAMOTO1), Sumio KITAJIMA and Kenji TOBITA
Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan
1)
Department of Applied Energy, Nagoya University, Nagoya 464-8603, Japan
(Received 6 April 2020 / Accepted 9 June 2020 / Published 6 August 2020)

Abstract

The dependence of hydrogen plasma parameters on magnetic field configuration and neutral pressure was investigated in the radio-frequency (RF) plasma source DT-ALPHA. It was found that higher electron density was obtained when the lower hybrid resonance condition was satisfied near the RF antenna. It was also found that use of lower hydrogen neutral pressure yielded higher electron density plasma. By optimizing the resonance condition and neutral pressure, the hydrogen plasma of Te ∼ 10 eV and ne > 1 × 1017 m−3 was achieved.

Keywords

divertor, volumetric recombination, hydrogen plasma, radio-frequency plasma, DT-ALPHA

DOI: 10.1585/pfr.15.1201056

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