Plasma and Fusion Research

Volume 14, 1401051 (2019)

Regular Articles

Increased Energy Absorption into W due to the Metal Deposited Layer from an ELM-like Pulsed Plasma
Takaya NAKAMORI, Noriyasu OHNO, Hirohiko TANAKA, Shin KAJITA1), Yusuke KIKUCHI2) and Tsuyoshi AKIYAMA3)
Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
1)
Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan
2)
Graduate School of Engineering, University of Hyogo, Himeji 671-2280, Japan
3)
National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
(Received 28 November 2018 / Accepted 8 February 2019 / Published 19 March 2019)

Abstract

It is important in divertor physics research to investigate thermal response process of beryllium deposited tungsten to high transient heat load such as ELMs. We investigated the heat load on aluminum-coated tungsten by comparing the measured back surface temperature and calculation results of the one-dimensional heat conduction equation. When the plasma power was low enough so that the evaporation did not occur sufficiently, the heat load on the aluminum-coated tungsten was higher than the virgin tungsten. It was caused by the reduction in the energy reflection coefficient due to the formation of aluminum layer. The results suggested that the beryllium deposited layer adversely affects the heat load on the divertor plate when the heat load was not high such as Grassy-ELM.

Keywords

aluminum coating, plasma gun, energy reflection, vapor shielding

DOI: 10.1585/pfr.14.1401051

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