Measurements of the fast ion slowing-down times in the HL-2A tokamak and comparison to classical theory
- Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China)
- National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)
Physics related to fast ions in magnetically confined fusion plasmas is a very important issue, since these particles will play an important role in future burning plasmas. Indeed, they will act as primary heating source and will sustain the self-ignited condition. To measure the fast ion slowing-down times in a magnetohydrodynamic-quiescent plasmas in different scenarios, very short pulses of a deuterium neutral beam, so-called 'blip,' with duration of about 5 ms were tangentially co-injected into a deuterium plasmas at the HuanLiuqi-2A (commonly referred to as HL-2A) tokamak [L. W. Yan, Nucl. Fusion 51, 094016 (2011)]. The decay rate of 2.45 MeV D-D fusion neutrons produced by beam-plasma reactions following neutral beam termination was measured by means of a {sup 235}U fission chamber. Experimental results were compared with those predicted by a classical slowing-down model. These results show that the fast ions are well confined with a peaked profile and the ions are slowed down classically without significant loss in the HL-2A tokamak. Moreover, it has been observed that during electron cyclotron resonance heating the fast ions have a longer slowing-down time and the neutron emission rate decay time becomes longer.
- OSTI ID:
- 22068892
- Journal Information:
- Physics of Plasmas, Vol. 19, Issue 11; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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