Investigation of the effects of transient heat loads on plasma-facing materials in Tokamaks

TL;DR

This paper investigates how transient heat loads in Tokamaks, especially in ITER, cause damage to plasma-facing materials like tungsten, through simulations of thermal stress and fracture.

Contribution

It provides a simulation-based analysis of tungsten's fracture behavior under various transient heat loads in Tokamaks, highlighting potential damage mechanisms.

Findings

Transient heat loads can cause significant damage to tungsten materials.

Simulations show fracture thresholds under different heat load scenarios.

Results inform material design for improved durability in fusion devices.

Abstract

Nuclear fusion devices are constantly under the threat of malfunctions coming from the damages of plasma-facing materials due to being affected by thermal heat loads. The frequent heat loads during some transient events in large-scale Tokamaks have always been a great concern for researchers. In ITER, the heat load of GW/m2 is estimated to impose plasma-facing components during edge localized modes, beside the Tokamak steady state load which is about 20 MW/m2. Moreover, there are also other transient thermal loads occurring due to off-normal operation of ITER such as vertical displacement events or disruptions, at the orders of hundreds of MW/m2 and tens of GW/m2, respectively. These loads are great enough to result in severe damages of plasma-facing materials. In this study, the facture of tungsten material under the heat loads of Tokamaks is simulated and the results are presented.