[Table of Contents]

Plasma and Fusion Research

Volume 5, S1022 (2010)

Regular Articles

Transport Analysis of High-Z Impurities Including Sawtooth Effects in a Tokamak System
Ikuhiro YAMADA, Kozo YAMAZAKI, Tetsutarou OISHI, Hideki ARIMOTO and Tatsuo SHOJI
Nagoya University, Nagoya, Aichi 464-8603, Japan
(Received 14 January 2009 / Accepted 27 September 2009 / Published 26 March 2010)


In fusion reactors, high-Z materials will be used to balance the need to accommodate high heat load on divertor plates against consistency between fusion burning plasmas and plasma facing component (PFC) materials. However, high-Z impurities from these PFCs cause large radiation loss even if the amount of impurities is quite small. High-Z impurity transport analysis including sawtooth effects is carried out using the toroidal transport analysis linkage (TOTAL) code. The Bohm-type anomalous transport model for the core plasma and the anomalous inward flow model for impurity ions are used in addition to neoclassical transport. After comparisons with Joint European Torus (JET) impurity transport data, sawtooth effects on impurity transport in ITER are clarified with a simplified full magnetic reconnection model. The critical levels of impurity concentration in ITER are found to be 4.0 % for carbon, 0.1 % for iron, and 0.008 % for tungsten with respect to electron density. Forming an internal transport barrier (ITB) for electron density can prevent high-Z impurity accumulation. Also, sawtooth oscillation is shown to be beneficial, reducing radiation loss from the plasma core by about 20 %, although it might lead to unfavorable fusion power fluctuation of 10 %.


impurity, transport, sawtooth oscillation, internal transport barrier, tokamak

DOI: 10.1585/pfr.5.S1022


  • [1] K. Yamazaki and T. Amano, Nucl. Fusion 32, 633 (1992).
  • [2] A. Taroni et al., Plasma Phys. Control. Fusion 36, 1629 (1994).
  • [3] T. Amano, J. Mizuno and J. Kako, ‘Simulation of Impurity Transport in Tokamak', Internal report IPPJ-616, Institute of Plasma Physics, Nagoya Univ. (1982).
  • [4] W. A. Houlberg et al., Phys. Plasmas 4, 3230 (1997).
  • [5] Y. Murakami, T. Amano et al., J. Nucl. Mater. 313-316, 1161 (2003)
  • [6] K. Yamazaki et al., J. Plasma Fusion Res. SERIES 7, 102 (2006).
  • [7] R. A. Hulse, Nucl. Technol. Fusion 3, 259 (1983).
  • [8] M. H. Huges and D. E. Post, J. Comput Phys. 28, 43 (1978).
  • [9] M. E. Puiatti et al., Plasma Phys. Control. Fusion 44, 1863 (2002).
  • [10] M. E. Puiatti et al., Plasma Phys. Control. Fusion 45, 2011 (2003).

This paper may be cited as follows:

Ikuhiro YAMADA, Kozo YAMAZAKI, Tetsutarou OISHI, Hideki ARIMOTO and Tatsuo SHOJI, Plasma Fusion Res. 5, S1022 (2010).