Plasma and Fusion Research

Volume 12, 1405040 (2017)

Regular Articles

Development of a Compact Divertor Plasma Simulator for Plasma-Wall Interaction Studies on Neutron-Irradiated Materials
Noriyasu OHNO, Tatsuya KUWABARA, Makoto TAKAGI, Ryo NISHIMURA, Miyuki YAJIMA1), Akio SAGARA1), Takeshi TOYAMA2), Katuya SUZUKI2), Hiroaki KURISHITA2), Tatsuo SHIKAMA2), Yuji HATANO3) and Naoaki YOSHIDA4)
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
1)
National Institute for Fusion Science, Oroshi-cho, Toki, Gifu 509-5292, Japan
2)
Institute for Materials Research, Tohoku University, Oarai-machi, Ibaraki 311-1313, Japan
3)
Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555, Japan
4)
Research Institute for Applied Mechanics, Kyushu University, Kasuga-kouen, Kasuga, Fukuoka 816-8580, Japan
(Received 2 June 2017 / Accepted 30 August 2017 / Published 16 October 2017)

Abstract

We have developed a compact divertor plasma simulator (CDPS) that can produce steady-state deuterium and/or helium plasmas with densities above ∼ 1018 m−3 for Plasma-Wall Interaction (PWI) studies of neutron-irradiated materials. The maximum particle flux is about 1022 m−2s−1. The CDPS was installed and is being operated in the radiation-controlled area of the International Research Center for Nuclear Materials Science, Institute for Materials Research, Tohoku University. We are able to control sample temperature within uncertainty of 5 °C during plasma exposure by adjusting the cooling air flow rate to the sample holder. The CDPS has a sample-carrier system, which makes it possible to transfer a plasma-irradiated sample from the sample holder to an infrared heater for analysis using thermal desorption spectroscopy (TDS) without exposing it to the air. This avoids the oxidation of the sample and minimizes the time between the end of plasma exposure and TDS analysis. An ITER-like tungsten (W) sample (A.L.M.T. Corp.), which has been irradiated by neutrons to 0.06 dpa in a fission reactor, was exposed to a deuterium plasma in the CDPS. The experimental results clearly show that the total deuterium retention in the neutron-irradiated W sample increases significantly in comparison with a pristine W, as demonstrated by broadening of the TDS spectrum at high temperatures.

Keywords

plasma-wall interaction, divertor plasma simulator, neutron-irradiated material, hydrogen isotope retention

DOI: 10.1585/pfr.12.1405040

Full Text

PDF format (2.5Mbytes) PDF Download

References

  • [1] J. Roth and K. Schmid, Phys. Scr. T145, 014031 (2011).
  • [2] M. Shimada et al., Fusion Eng. Des. 87, 1166 (2012).
  • [3] Y. Hatano et al., J. Nucl. Mater. 438, S114 (2013).
  • [4] Y. Hatano et al., Nucl. Fusion 53, 073006 (2013).
  • [5] B. Unterberg et al., Fusion Eng. Des. 86, 1797 (2011).
  • [6] R.J. Ellis et al., Fusion Sci. Technol. 68, 750 (2015).
  • [7] H. Kurishita et al., Plasma Fusion Res. 9, 3405136 (2014).
  • [8] N. Ohno, Plasma Phys. Control. Fusion 59, 034007 (2017).
  • [9] M. Yamagiwa et al., Phys. Scr. T145, 014032 (2011).