Abstract
It has been suggested that by electrically biasing the divertor tiles in a tokamak, one could create a toroidally-asymmetric potential structure in the scrape-off layer (SOL) plasma. The resultingE×B convective motion should increase the plasma transport in the SOL and thereby reduce the heat load on the divertor plates. This paper describes plans for such experiments on COMPASS-D and preliminary theoretical modelling. The COMPASS-D divertor target consists of 24 graphite tiled toroidal segments. The inner and outer strike point tiles on all these segments will be insulated from each other, and cabling will be installed to allow for biasing of individual tiles in any combination. Theoretical analysis suggests that the electrostatic potential perturbations caused by the biasing will be confined to the divertor region below the X-point, and that substantial SOL broadening can be achieved by applying modest voltages. Aside from active control of SOL transport, it is hoped that the biasing will be useful to probe other divertor and SOL physics issues.
Similar content being viewed by others
References
R. Cohen and D. Ryutov: Nucl. Fusion37 (1997) 621.
R.R. Weynants and G. van Oost: Plasma Phys. Control. Fusion35 (1993) B177, and literature cited therein.
J. Stoeckel et al.: inProc. 27th Conf. on Controlled Fusion and Plasma Physics, Budapest 2000 (Eds. K. Szegö, T.N. Todd, and S. Zoletnik), European Physical Society, 2000.
G.G. Castle, A.W. Morris, D. Gates, M. Valovic: inProc. 23rd EPS Conf. on Controlled Fusion and Plasma Physics, Kiev 1996, (Eds. G. Gresillon, A. Sitenko, and A. Zagorodny), European Physical Society, 2000. Vol. I, p. 139.
S.J. Fielding, R.H. Cohen, P. Helander and D.D. Ryutov: submitted to J. Nucl. Mat. (2000).
D. Farina, R. Pozzoli, and D. Ryutov: Nucl. Fusion33 (1993) 1315.
Ya.B. Zeldovich: Sov. Phys. Dokl.27 (1982) 797.
D.A. D’Ippolito and J.R. Myra: Czech. J. Phys.49, Suppl. S3, (1999) 55.
V. Rozhansky and M. Tendler: inReviews of Plasma Physics, Consultants Bureau, New York, 1996, Vol. 19, p. 147.
M.V. Umansky, S.I. Krasheninnikov, B. LaBombard, and J.L. Terry: Phys. Plasmas5 (1998) 3373.
Author information
Authors and Affiliations
Additional information
This work was jointly funded by the UK Department of Trade and Industry and Euratom, and was supported by US DoE under contract W-7405-ENG-48 at LLNL.
Rights and permissions
About this article
Cite this article
Helander, P., Fielding, S.J., Cohen, R.H. et al. Electric biasing of the divertor tiles in compass-D. Czech J Phys 50, 1421–1430 (2000). https://doi.org/10.1023/A:1022851714099
Received:
Issue Date:
DOI: https://doi.org/10.1023/A:1022851714099