Abstract
A numerical study of the diamagnetic drift effect on the nonlinear interaction between multi-helicity neoclassical tearing modes(NTMs)is carried out using a set of four-field equations including two-fluid effects.The results show that,in contrast to the single-fluid case,5/3 NTM cannot be completely suppressed by 3/2 NTM with diamagnetic drift flow.Both modes exhibit oscillation and coexist in the saturated phase.To better understand the effect of the diamagnetic drift flow on multiple-helicity NTMs,the influence of typical relevant parameters is investigated.It is found that the average saturated magnetic island width increases with increasing bootstrap current fraction fb but decreases with the ion skin depth δ.In addition,as the ratio of parallel to perpendicular transport coefficients x||/x⊥ increases,the average saturated magnetic island widths of the 3/2 and 5/3 NTMs increase.The underlying mechanisms behind these observations are discussed in detail.
基金项目
国家重点研发计划(2022YFE03090000)
国家自然科学基金(11925501)
国家自然科学基金(12075048)
Fundament Research Funds for the Central Universities(DUT22ZD215)
NETL
NSTL
万方数据