12 / 2021-04-06 23:42:13

Simulations of 3D edge plasma transports in high-beta high-density scenarios on W7-X with the island divertor

EMC3-EIRENE,high-beta,island divertor

One of the W7-X experimental goals is demonstrating high-beta plasmas in steady states with the island divertor. At this level, the finite-beta MHD effect is strong enough to modify the magnetic field distributions according to the nonlinear 3D equilibrium modeling by the HINT code. Here, the influence of such magnetic topology changes on edge plasma transports in the standard configuration is studied by using 3D fluid edge plasma Monte-Carlo code (EMC3) coupled to a kinetic neutral particle transport code (EIRENE). Compared with the vacuum field cases, the simulations with a constant input power support that the threshold separatrix density for accessing the power detachment is reduced in high-beta plasmas. A series of parameter scan modeling also demonstrates the changes of divertor heat loads, the impurity radiation and the recycling flux in high-beta high-density scenarios on W7-X.