[Table of Contents]

Plasma and Fusion Research

Volume 2, 042 (2007)

Regular Articles

Escaping Ion Measurement with High Time Resolution during Bursting Modes Induced by Neutral Beam Injection on CHS
Kouji SHINOHARA, Mitsutaka ISOBE1), Douglass S. DARROW2), Akihiro SHIMIZU1), Kenichi NAGAOKA1) and Shoichi OKAMURA1)
Japan Atomic Energy Agency
1)
National Institute for Fusion Science
2)
Princeton Plasma Physics Laboratory
(Received 16 April 2007 / Accepted 10 August 2007 / Published 3 September 2007)

Abstract

A bursting mode, whose time scale is a few milliseconds, is excited in low density neutral beam injected plasmas in the compact helical system. A scintillator-based probe equipped with a high speed video camera has been used to investigate the energetic ion losses induced by this fast evolving mode. This instrument reveals loss in a region of the gyroradius and the pitch angle space that occurs only during a burst. Namely, it was found that the bursting mode induces the transport of energetic ions to the region where the energetic ions cannot exist without such an enhanced transport. The dependence of the newly observed loss on the electron density and the neutral beam injected power was also investigated.

Keywords

energetic ion, escaping ion measurement, beam driven mode, heliotron/torsatron device, magnetic confinement

DOI: 10.1585/pfr.2.042

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This paper may be cited as follows:

Kouji SHINOHARA, Mitsutaka ISOBE, Douglass S. DARROW, Akihiro SHIMIZU, Kenichi NAGAOKA and Shoichi OKAMURA, Plasma Fusion Res. 2, 042 (2007).