Plasma and Fusion Research

Volume 4, 004 (2009)

Regular Articles

Visualized Blow-off from Helium Irradiated Tungsten in Response to ELM-like Heat Load
Shin KAJITA, Noriyasu OHNO1), Wataru SAKAGUCHI1) and Makoto TAKAGI1)
EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan
1)
Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan
(Received 28 November 2008 / Accepted 25 December 2008 / Published 6 February 2009)

Abstract

Laser-induced blow-off from a tungsten surface that was exposed to helium plasma is investigated experimentally in the divertor simulator NAGDIS-II. The pulse width of the laser is submillisecond and is similar to the duration of type-I edge localized modes in ITER. The temporal evolution of blow-off particles, which are visualized by the electron impact excitation in the surrounding plasma, is investigated by using filter spectroscopy. We demonstrate the effect of helium irradiation damages on the tungsten ejection behavior in response to a transient heat load.

Keywords

NAGDIS-II, helium irradiation, tungsten, transient heat load

DOI: 10.1585/pfr.4.004

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This paper may be cited as follows:

Shin KAJITA, Noriyasu OHNO, Wataru SAKAGUCHI and Makoto TAKAGI, Plasma Fusion Res. 4, 004 (2009).