The local stability of heliacs with different types of quasisymmetry
The beta limits with respect to ballooning and Mercier stability have been calculated for 4-period Heliac-like stellarators using the TERPSICHORE code. The results for Heliacs were compared with two types of the magnetic field symmetry. In the first the magnetic field strength has quasihelically symmetric structure, while in the second the magnetic field strength depends mainly on the toroidal coordinate on each magnetic surface corresponding to a quasi-mirror symmetric system. The Mercier criterion is stable in the both cases at the level of 4%, but the beta limit with respect to ballooning modes in the quasi-mirror case is 3 times higher than in the quasihelically symmetric case and equals to 3%.
Bibliographic Reference: Article: Journal of Plasma Fusion Research SERIES, Vol. 1 (1998) pp. 66-69
Record Number: 199811014 / Last updated on: 1998-09-15
Original language: en
Available languages: en