Simulation analysis of the design of a vacuum pumping system for the closed helical divertor in the large helical device

Abstract

A promising candidate of a vacuum pumping system for the closed helical divertor in the large helical device is proposed using a three-dimensional neutral particle transport simulation code (EIRENE) and a finite element based multi-physics analysis software (ANSYS). It shows that heat load on a gas/liquid He cooled panel by thermal conduction due to high energy neutral hydrogen atoms is dominant over that by radiation from divertor plates heated by the LHD peripheral plasma. It proves that optimization of the configuration of the vacuum pumping system can significantly reduce the heat load on the panel without serious degradation of the pumping efficiency. © 2011 The Japan Society of Plasma Science and Nuclear Fusion Research.