Progress in the Study of RF Heating and Stabilization on HANBIT Mirror Device
The HANBIT device is a simple mirror-type device of which the length, radius, and magnetic field are about 5 m, 0.18 m, and 0.1-0.3 T, respectively, in the central cell. In HANBIT, two antenna systems are used for the plasma production, heating, and MHD stabilization; one is the slot antenna located near the center region with the maximum power of 500 kW and the typical frequency of 3.5 MHz, and the other DHT antenna located near the mirror throat with the maximum power of 100 kW and the frequency of 3.75 MHz. Recent experimental studies in HANBIT indicate that the slot antenna system can produce stable, high-density plasmas in apparently two different regimes; one is the fast wave regime with the ratio w/Wci{approx}2 and the other is the slow wave regime with w<Wci, where w and Wci are the RF and ion cyclotron resonance frequencies, respectively. The possible stabilization mechanism appears to be the ponderomotive force by the fast wave in the regime of w/Wci{approx}2, while the RF side-band coupling force by the slow wave in the regime of w<Wci. A clear excitation of the flute-type, interchange modes with the axial mode number n=0 is observed when the RF power is not enough for the stabilization, particularly, in the slow wave regime. Here, we report the results of these experimental and theoretical studies on the RF heating and stabilization processes by the slot antenna in HANBIT. In addition, we introduce briefly the results of the other on-going research works in HANBIT, which include the beach-wave ion heating experiment using DHT antenna, the pre-ionization experiment using the thermal electron cathode or ECH, and the analysis of plasma-wall interaction and neutral transport.
- OSTI ID:
- 20849781
- Journal Information:
- Fusion Science and Technology, Vol. 47, Issue 1T; Other Information: Copyright (c) 2006 American Nuclear Society (ANS), United States, All rights reserved. http://epubs.ans.org/; Country of input: International Atomic Energy Agency (IAEA); ISSN 1536-1055
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANTENNAS
CATHODES
COUPLING
ECR HEATING
ELECTRONS
EXCITATION
ION CYCLOTRON-RESONANCE
IONIZATION
IONS
MAGNETIC FIELDS
MAGNETIC MIRRORS
MAGNETOHYDRODYNAMICS
MHZ RANGE
PLASMA DENSITY
PLASMA PRODUCTION
PONDEROMOTIVE FORCE
RADIATION TRANSPORT
STABILIZATION
WALL EFFECTS