[Table of Contents]

Plasma and Fusion Research

Volume 7, 2403083 (2012)

Regular Articles

Simulation of Deuterium Retention in Tungsten Exposed to Divertor Plasmas
Kaoru OHYA and Yoshio SONEDA
Institute of Technology and Science, The University of Tokushima, Tokushima 770-8506, Japan
(Received 28 November 2011 / Accepted 2 May 2012 / Published 26 July 2012)

Abstract

To study tritium retention in a divertor target made of tungsten, thermal processes of hydrogen isotopes, including implantation, diffusion, trapping and detrapping, and surface recombination, are modeled for ITER plasma configuration. The material parameters governing the processes are estimated by simulating an existing TDS experiment by using the model. In case of the inner target, dominant retention mechanism is the trapping in the deep trap and most of the T atoms are kept in the trap even after discharge. Mobile T atoms dominate the T retention in the outer target due to its high temperature, the amount of which is ten times greater than that in the inner target. The T retention after a discharge of 400 s is estimated to be tens of mg, resulting in 10000 or more discharges after which a T safety limit of 700 g is reached. Nevertheless, it strongly depends on the trap concentration in the target.

Keywords

plasma-wall interaction, ITER, divertor, tritium retention, tungsten, diffusion, trapping

DOI: 10.1585/pfr.7.2403083

Full Text

PDF format (791Kbytes) PDF Download

References

  • [1] T. Tanabe et al., J. Nucl. Mater. 196-198, 11 (1992).
  • [2] K.L. Wilson et al., J. Nucl. Mater. 76/77, 291 (1978).
  • [3] M.A. Pick et al., J. Nucl. Mater. 131, 208 (1985).
  • [4] K. Ohya, Phys. Scr. T124, 70 (2006).
  • [5] C. Garcia-Rosales et al., J. Nucl. Mater. 233-237, 803 (1996).
  • [6] T. Ono et al., J. Nucl. Mater. 390-391, 713 (2009).
  • [7] R.A. Anderl et al., Fusion Technol. 21, 745 (1992).
  • [8] W.R. Wampler, J. Nucl. Mater. 145-147, 313 (1987).
  • [9] G. Federici et al., J. Nucl. Mater. 313-316, 11 (2003).
  • [10] K. Inai et al., J. Plasma Fusion Res. SERIES 8, 433 (2009).
  • [11] K. Ohya et al., J. Nucl. Mater. 417, 637 (2011).
  • [12] G. Federici et al., Plasma Phys. Control. Fusion 45, 1523 (2003).

This paper may be cited as follows:

Kaoru OHYA and Yoshio SONEDA, Plasma Fusion Res. 7, 2403083 (2012).