Effect of bulk temperature on erosion of tungsten plasma-facing components subject to simultaneous deuterium plasma and heat pulses

Abstract

In fusion tokamaks, when an ELM occurs, a considerable amount of energy can be deposited on the divertor. This transient causes heating and material loss of plasma-facing components (PFCs). We have integrated laser systems into the existing PFC research program in PISCES, a laboratory facility capable of reproducing plasma–materials interactions expected during normal operation of large tokamaks. We previously showed that tungsten samples exhibit significant ‘collateral damage’ in the form of increased mass loss when a heat pulse is applied in a plasma background due to synergistic effects of the thermal pulse and plasma exposure. New experiments indicate that surfaces exposed to deuterium plasma above 500 °C do not exhibit increased mass loss. One explanation of this result may be that retained deuterium migrates to locations deeper than the heat pulse propagation depth.