Direct construction of optimized stellarator shapes. Part 3. Omnigenity near the magnetic axis
Abstract
The condition of omnigenity is investigated, and applied to the near-axis expansion of Garren & Boozer (Phys. Fluids B, vol. 3 (10), 1991a, pp. 2805-2821). Due in part to the particular analyticity requirements of the near-axis expansion, we find that, excluding quasi-symmetric solutions, only one type of omnigenity, namely quasi-isodynamicity, can be satisfied at first order in the distance from the magnetic axis. Our construction provides a parameterization of the space of such solutions, and the cylindrical reformulation and numerical method of Landreman & Sengupta (J. Plasma Phys., vol. 84 (6), 2018, 905840616); Landreman et al. (J. Plasma Phys., vol. 85 (1), 2019, 905850103), enables their efficient numerical construction.
- Publication:
-
Journal of Plasma Physics
- Pub Date:
- December 2019
- DOI:
- 10.1017/S002237781900062X
- arXiv:
- arXiv:1909.08919
- Bibcode:
- 2019JPlPh..85f9002P
- Keywords:
-
- fusion plasma;
- plasma confinement;
- plasma devices;
- Physics - Plasma Physics
- E-Print:
- doi:10.1017/S002237781900062X