Surface biasing influence on the physical sputtering in fusion devices

Abstract

A new simplified analytical expression for the electromagnetic field in the Debye sheath in the presence of an oblique magnetic field including surface biasing effect is suggested. It is in good agreement with the numerical solution of the integral equation for the potential distribution in the Debye sheath. The energy and angular impact distributions and corresponding surface sputtering yields were analyzed in the presence of an oblique magnetic field and surface biasing. The analytical expression was used to estimate a) the effective sputtering yield of the W target with a varying negative voltage against plasma in PSI-2 linear device and b) erosion of the JET outer wall Be limiter near the ICRH antenna enhanced during RF emission.