Effect of Neoclassical Transport Optimization on Energetic Ion Confinement in LHD

Journal Article · Wed Sep 15 04:00:00 EDT 2004 · Fusion Science and Technology

OSTI ID:20849740

Murakami, S ^[1]; Yamada, H ^[2]; Sasao, M ^[3]

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1. Kyoto University (Japan)
2. National Institute for Fusion Science (Japan)
3. Tohoku University (Japan)

Confinement of energetic ions from neutral beam injection heating is investigated by changing the magnetic field configuration of the Large Helical Device from a classical heliotron configuration to an optimized neoclassical transport configuration to a level typical of ''advanced stellarators.'' The experimental results show the highest count rate of fast neutral particles not in the optimized configuration but in the inward-shifted one. The GNET simulation results show a relatively good agreement with the experimental results, and they also show a lower energy loss rate in the optimized configuration. This contradiction can be explained by the radial profile of the energetic ions. The relatively good agreement between experimental and simulation results suggest that ripple transport (neoclassical) dominates the energetic ion confinement and that the optimization process is effective in improving confinement in helical systems.

• OSTI ID: 20849740
• Journal Information: Fusion Science and Technology, Journal Name: Fusion Science and Technology Journal Issue: 2 Vol. 46; ISSN 1536-1055
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM INJECTION HEATING
COMPUTERIZED SIMULATION
COUNTING RATES
HELIOTRON
LHD DEVICE
MAGNETIC FIELD CONFIGURATIONS
NEOCLASSICAL TRANSPORT THEORY
NEUTRAL PARTICLES
OPTIMIZATION
PLASMA CONFINEMENT
PLASMA SIMULATION
RADIATION TRANSPORT
STELLARATORS
TAIL IONS