1 - Nuclear Sciences and Applications - IAEA

436 BAGDASAROV et a!.
suppression for heating of different sides of the q = 2 surface is related to the variation
of current density gradient in the vicinity of this surface. The suppression of the
m = 2 mode under on-axis heating is determined by an integral effect of the current
profile on the stability. The main role is played here by the values of the shear and
the poloidal magnetic field in the vicinity of the q = 2 surface.
One of the possible explanations for the result obtained on the anomalous rate
of current penetration into the plasma is related to the destruction of the structure of
the isolated magnetic surfaces which occurs at variations of the current density profile.
The simple diffusion approximation for the current penetration through the
plasma becomes invalid in this case. This is confirmed by the result of calculations
(Fig. 14) made within the framework of our model. In Fig. 14, we see that in the
calculations, as in the experiment, the phase of the oscillations of the q =2 surface
radius virtually coincides with the phase of the discharge current oscillations. A rise
in the electron energy confinement time at the stage of current increase (Fig. 14) is
natural for the model since the variation in the current density profile assists in the
improvement of tearing mode stability in the interior of the plasma column. A similar
T£e behaviour is also observed in the experiment.
REFERENCES
[1] ALIKAEV, V.V., et al., in Controlled Fusion and Plasma Physics (Proc. 14th Eur. Conf.
Madrid, 1987), Vol. 11D, Part I, European Physical Society (1987) 125.
[2] ALIKAEV, V.V., et al., Pis'ma Zh. Ehksp. Teor. Fiz. 40 (1984) 327.
[3] VOLKOV, V.V., et al., Rep. IAE-405577, Institute of Atomic Energy, Moscow (1984).
[4] VASIN, N.L., et al., Fiz. Plazmy 12 (1986) 259.
[5] RUTHERFORD, P.H., Phys. Fluids 16 (1973) 1903.
[6] IVANOV, N.V., et al., Fiz. Plazmy 10 (1984) 432.
[7] IVANOV, N.V., Fiz. Plazmy 9 (1983) 703.
[8] DNESTROVSKIJ, Yu.N., et al., Computational Methods in Plasma Physics, Moscow (1984).
[9] GONDHALEKAR, A., et al., in Plasma Physics and Controlled Nuclear Fusion Research 1978
(Proc. 7th Int. Conf. Innsbruck, 1978), Vol. 1, IAEA, Vienna (1979) 199.
[10] VLASENKOV, V.S., et al., ibid., p. 211.
[11] MURAKAMI, M., et al., ibid., p. 269.
[12] WAGNER, F., et al., in Plasma Physics and Controlled Nuclear Fusion Research 1982 (Proc.
9th Int. Conf. Baltimore, 1982), Vol. 1, IAEA, Vienna (1983) 43.
[13] GOLDSTON, R., Plasma Phys. Contrail. Fusion 26 (1984) 87.
[14] ALIKAEV, V.V., et al., in Plasma Physics and Controlled Nuclear Fusion Research 1984 (Proc.
10th Int. Conf. London, 1984), Vol. 1, IAEA, Vienna (1985) 419.
[15] ALIKAEV, V.V., et al., in Plasma Physics and Controlled Nuclear Fusion Research 1986 (Proc.
11th Int. Conf. Kyoto, 1986), Vol. 1, IAEA, Vienna (1987) 111.
[16] BAGDASAROV, A.A., et al., in Plasma Physics and Controlled Nuclear Fusion Research 1982
(Proc. 9th Int. Conf. Baltimore, 1982), Vol. 3, IAEA, Vienna (1983) 281.
[17] FREDRICKSON, E.D., et al., Nucl. Fusion 26 (1986) 849.
[18] T-10 GROUP, in Controlled Fusion and Plasma Physics (Proc. 12th Eur. Conf. Budapest, 1985),
Vol. 9F, Part I, European Physical Society (1985).