Qps Transport and Energetic Particle Physics
Abstract
The transport and confinement of compact quasi-poloidal stellarators (QPS) have been evaluated using computational tools that accurately model the strong toroidal coupling characteristic of the magnetic field structure at low aspect ratios (A < 3). Core neoclassical transport issues of interest include the perpendicular fluxes of particles and energy, bootstrap current, self-consistent ambipolar states, and flow damping viscosity. These topics have been addressed using both local diffusive models (such as the DKES and NEO codes) and non-local particle-based Monte Carlo techniques. Energy lifetime estimates will be made for QPS devices and comparisons will be made between the different models. Energetic particle confinement is generally more sensitive to the structure of |B| due to the lower collisionalities. Particle based codes (DELTA5D) can follow the evolution of fast ion populations (alphas, ICRF tails) through slowing-down timescales, allowing estimates of heating efficiency. The excitation of Alfvén (AE) instabilities by antennas/fast ions in 3D systems has been addressed using a high-resolution calculation of the AE continua and mode structures.
- Publication:
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APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 2002
- Bibcode:
- 2002APS..DPPCP1087S