Forced magnetic reconnection due to transient resonant magnetic perturbations in flowing tokamak plasmas

Asymptotic matching techniques are used to investigate the linear drift-magnetohydrodynamical response of a flowing tokamak plasma to a transient resonant magnetic perturbation (RMP). It is demonstrated that knowledge of the solution of the “Taylor problem,” in which the RMP is suddenly switched on, and subsequently held steady, is sufficient to solve for the response of a transient RMP of arbitrary time dependence. The reconnected magnetic flux driven by the RMP is calculated as a function of time via two alternative methods. The first solution method, which is exact, but time-consuming, involves the numerical evaluation of a contour integral in Laplace transform space. The second solution method, which is approximate, but much less time-consuming, involves closed-form analytic solutions in one of seven different response regimes. The results of the two solution methods are compared.