1 - Nuclear Sciences and Applications - IAEA

CONCLUSION
IAEA-CN-50/A-VU-1S 503
Well-controlled tokamak discharges with q values as low as 2.1 have been obtained
in initial ohmic operation of the Tokamak de Varennes with graphite limiters. Disruptionfree
current rampdown at 4 MA/s has been achieved. Measurements of the temperature and
density profiles, global confinement time, Ze» and sawtooth inversion radius agree with the
expected values, as does the hydrogen implantation depth. UV outgassing has been found
to be effective for wall conditioning, as has low pressure glow discharge cleaning.
Expe'riments with refractive TiC coatings, while not yet successful, have nevertheless
indicated adhesion of the coating. Future experiments on the Tokamak de Varennes will be
carried out using a double-null divertor.
ACKNOWLEDGEMENTS
Successful construction and operation of the Tokamak de Varennes is in large
measure due to the unstinting efforts of the technical staff, the engineering staff, the control,
data acquisition, and programming staff, the theory and interpretation group and the staff
of the Centre canadien de fusion magn6tique. We gratefully acknowledge their
contributions. The Centre canadien de fusion magn6tique is funded by Atomic Energy of
Canada Limited, Hydro-Que"bec, and Institut national de la recherche scientifique.
REFERENCES
[1] COUTURE, P., GEOFFRION, J., GREGORY, B.C., VAN ANDEL, H.W.H., BOLTON,
R.A., in Engineering Problems of Fusion Research (Proc. 9th Symp. Chicago, 1981), Vol. 2
(1981) 1701.
[2] HARBEC, G., et al., in Proc. 12th SOFT, Julich (1982) 411.
[3] GOLDSTON, R.J., Plasma Phys. Controll. Fusion 26 (1984) 87.
[4] TFR GROUP, in Plasma Physics and Controlled Nuclear Fusion Research 1976 (Proc. 6th Int.
Conf. Berchtesgaden, 1976), Vol. 1, IAEA, Vienna (1977) 279.
[5] KALNAVARNS, J., et al., in Fusion Engineering (Proc. 12th Symp. Monterey, 1987) 1370.
[6] PACHER, H.D., GREGORY, B.C., PACHER, G.W., Nucl. Fusion 26 (1986) 507.
[7] STOTLER, D., BATEMAN, G., Simulation of a Compact Ignition Tokamak Discharge,
Rep. PPPL-2415, Plasma Physics Laboratory, Princeton Univ., NJ (1987).
[8] BRUNET, C, et al., J. Vac. Sci. Technol. A 3(6) (1985) 2503.
[9] TERREAULT, B., et al., in Plasma-Surface Interactions in Controlled Fusion Devices (Proc.
8th Int. Conf. Julich, 1988), to be published in J. Nucl. Mater.
[10] ROSS, G.G., et al., J. Nucl. Mater. 128&129 (1984) 730.