Characteristics of a repetitive ELM-like pulsed plasma source and its damage effects on tungsten target
Year: 2025
Type: article
Abstract: Transient thermal load events have great effects on the service life of plasma-facing materials (PFCs) in tokamak steady-state operation. A compact-sized repetitive discharge coaxial gun plasma source is developed in order to simulate transient heat loads such as type I edge-localized modes (ELMs-I) in ITER. In this paper, the plasma characteristics of repeated coaxial gun and the damage effects of different frequencies on tungsten target are studied. At a constant initial condition (charging voltage, gasflow), the voltage and current data reflects the discharge characteristics of the repeating plasma source. The gun produces helium plasma with an electron density of 1.62.0×1015 cm−3, an energy density of 0.2 MJ/m2, and a pulse width of 0.6 ms. The local surface heating evolution of W is clearly observed with the camera during repeated pulsed plasma exposure. By changing the discharge frequency of coaxial gun, it is found that the heat accumulation effect and thermal stress on the surface of tungsten target are intensified with the increase of shock frequency. High-frequency thermal shocks led to enhanced melting and accelerated crack propagation, with residual stresses on the target surface being released through crack formation. The simulation experiment results provide valuable insights into the interaction mechanisms between plasma and the first wall material at different frequencies in tokamaks.
Source: Fusion Engineering and Design
Authors: Liangwen Qi, Shuai Liu, Xiaodong Wen, Manqiang Du, Delong Guo, Chenxi Ren
Institutions: Lanzhou Jiaotong University, Xi'an Jiaotong University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,810
Awards: G7992220059, G8640483953
OpenAlex ID: W7083588259