Plasma elongation effect on the parity change in global electromagnetic ion temperature gradient modes and intrinsic rotation generation

Abstract

A study is made of the effect of plasma elongation (κ) on parity of a global electromagnetic (EM) ion temperature gradient mode and intrinsic rotation generation. An odd parity component of the mode is generated by global EM effects and increases with β (=plasma thermal energy/magnetic energy), enhancing the symmetry breaking and subsequent Reynolds stress [Kaang et al., Phys. Plasmas 25, 012505 (2018)]. The plasma elongation is shown to diminish the parity change via the reduction in the effective ion temperature gradient by a factor α=1−E′, where E=r(κ−1)/(κ+1). A quasi-linear analysis indicates that plasma elongation can weaken the generation of intrinsic torque induced by the global EM effect as a result of the decline of the parity change.