[Table of Contents]

Plasma and Fusion Research

Volume 8, 2402059 (2013)

Regular Articles

Impurity Transport Study with TESPEL Injection and Simulation
Shigeru SUDO, Naoki TAMURA, Hisamichi FUNABA, Sadatsugu MUTO, Chihiro SUZUKI and Izumi MURAKAMI
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
(Received 29 November 2012 / Accepted 26 March 2013 / Published 22 May 2013)

Abstract

Impurity behaviors in LHD are studied by a Tracer-encapsulated Solid Pellet (TESPEL) injection. By containing multiple tracers in a TESPEL, the different tracer species have been compared simultaneously under the same plasma condition. The density disturbance on the bulk plasma by TESPEL is typically less than 10 %. The amount of the tracer particles deposited locally inside a plasma is about a few 1017 particles which is smaller than that of the bulk plasma by a factor of three orders of magnitude. Triple tracers, V, Mn and Co are used, because the charges of nuclei of intrinsic impurities, Cr and Fe are in between those of the tracers. The impurity confinement behavior depends substantially on the electron density. In case of the density higher than ne = 5 × 1019 m−3, the tracer impurity in the plasma core was kept for a long time, while it decays in order of 500 ms in the medium density case. Such temporal behavior is compared with a STRAHL simulation code assuming diffusion coefficient and convection. The general behavior fits well with the emissivity value integrated along the sight line.

Keywords

TESPEL, pellet, tracer, impurity diagnostics, impurity transport

DOI: 10.1585/pfr.8.2402059

Full Text

PDF format (1.3Mbytes) PDF Download

References

  • [1] S. Sudo, J. Plasma Fusion Res. 69, 1349 (1993).
  • [2] S. Sudo et al., Plasma Phys. Control. Fusion 44, 129 (2002).
  • [3] S. Sudo et al., Plasma Phys. Control. Fusion 45, 1127 (2003).
  • [4] S. Sudo and N. Tamura, Rev. Sci. Instrum. 83, 023503 (2012).
  • [5] S. Sudo, N. Tamura et al., Nucl. Fusion 52, 063012 (2012).
  • [6] K. Behringer “Description of the impurity transport code STRAHL” JET-R(87)08, JET Joint Undertaking, Culham.
  • [7] K. Narihara et al., Rev. Sci. Instrum. 72, 1122 (2001).
  • [8] K. Kawahata et al., Rev. Sci. Instrum. 70, 707 (1999).
  • [9] Y. Nakamura et al., Nucl. Fusion 43, 219 (2003).
  • [10] S. Muto et al., Rev. Sci. Instrum. 72, 1206 (2001).
  • [11] J.L. Schwob, A.W. Wouters, S. Suckewer and M. Finkenthal, Rev. Sci. Instrum. 58, 1601 (1987).
  • [12] H.P. Summers “The ADAS User Manual”, version 2.6 (2004). http://www.adas.ac.uk
  • [13] K. Ida et al., Nucl. Fusion 44, 290 (2004).
  • [14] H.Y. Zhou, S. Morita, M. Goto et al., Plasma Fusion Res. 5, S1021 (2010).

This paper may be cited as follows:

Shigeru SUDO, Naoki TAMURA, Hisamichi FUNABA, Sadatsugu MUTO, Chihiro SUZUKI and Izumi MURAKAMI, Plasma Fusion Res. 8, 2402059 (2013).