Integrated simulation of plasma surface interaction during edge localized modes and disruptions: Self-consistent approach

Abstract

Edge-localized modes (ELMs) and disruptions remain a major concern to divertor plasma-facing components (PFCs) during normal and abnormal operation of future tokamaks. Of particular concern are the pulses of energy and particles that are transported during ELMs to the divertor surface. ELMs, therefore, can result in excessive divertor erosion and plasma contamination. A two-fluid model is enhanced to include detail atomic physics data for tungsten, lithium, and neon in multidimensional geometry to integrate core, SOL parameters, and divertor surface evolution (melting, vaporization, vapor cloud dynamics, etc.) using the HEIGHTS numerical simulation package. ELM mitigation using liquid Li surface and neon gas puffing are also simulated. Initial results indicate that a thin layer of Li (<1 mm) can fully protect the divertor surface from giant ELMs. Significant amount of neon gas puff (nL > 10 17 cm −2) is needed to prevent tungsten surface from melting during giant ELMs. Vapor impurity diffusion through the private flux region can be major source of plasma contamination during ELMs and could terminate the plasma in a disruption.