2-D MHD modeling of a divertor for ZT-P

Abstract

Summary form only given. A proposal has been put forth to build and install a divertor for ZT-P, a small RFP (reversed field pinch) at Los Alamos National Laboratory. One advantage of implementing the divertor on ZT-P would be the ability to examine ITER (International Thermonuclear Experimental Reactor)-regime heat fluxes on the divertor plates. Predictions of edge plasma parameters were examined qualitatively and quantitatively, and recommendations for divertor plate material were made based on estimates for predicted sputtering erosion. The code used for the analysis is B.J. Braams' 2-D MHD two-fluid edge transport code (1987). The primary changes made to the code to allow modeling of ZT-P are geometric changes for the computational mesh and parametric boundary condition changes, such as density and temperature at the interface with the core plasma. In the high-density, low-heat flux regime, it is predicted that divertor operation for ZT-P will significantly decrease impurity sputtering from the wall and plates as compared to present (no divertor) operation. In the low-density, high-heat flux regime, divertor operation should increase the total impurity sputtering from the wall and plates. In the mid-density, mid-heat flux regime, it is predicted that divertor operation will not have a large effect on impurity sputtering