THE EFFECT OF REDUCED PFIRSCH-SCHLUETER CURRENT ON
THE IDEAL MHD STABILITY AND ALPHA PARTICLE CONFINEMENT
IN 2-PERIOD COMPACT CONFIGURATIONS

M. Yu. Isaev1), S. Okamura2), W. A. Cooper3)

1)Nuclear Fusion Institute, RRC "Kurchatov Institute", Moscow, Russia
2)National Institute for Fusion Science, Toki, Japan
3) Centre de Recherches en Physique des Plasmas, EPFL, Lausanne, Switzerland

The CHS-qa 2b32 [1] configuration has been considered as a starting point for the further numerical optimisation towards small Pfirsch-Schlueter current. The configurations obtained have about 4 times smaller PS current and are stable with respect to Mercier modes for &beta values around 8.5%. However, the &alpha particle confinement and the MHD stability with respect to the ballooning modes appear to be more difficult issues to improve in the configurations obtained. In particular, the maximum value of &beta , stable with respect to the ballooning modes, has been obtained on the level of 2%. Detailed calculations of the configurations computed with the 3D fixed boundary ideal equilibrium code VMEC2000 [2], with the 3D ideal MHD stability code TERPSICHORE [3], which reconstruct the equilbirum state in Boozer magnetic coordinates and with the MCT [4] code, which follows collisionless mono-energetic &alpha -particles drift orbits, are presented.

References

[1] Okamura S. et al, Proc. of 29th EPS Conf. on Plasma Phys.
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[2] R. Sanchez, M.Isaev, S.Hirshman et al., Comput. Phys. Comm., &141 , 55(2001)
[3] Anderson D.V., et al., Scientific Computing on Supercomputers II,
Plenum Press, New York and London 159(1990). Cooper W.A., Plasma
Phys. Control. Fusion, &34 1011(1992)
[4] Fowler R.H., Rome J.A., Lyon J.F., Phys. Fluids, &28 , 338(1985)