Toroidicity effects in electrostatic drift wave turbulence in Tokamaks. II. The incoherent response
W Y Zhang; R Balescu; W Y Zhang; Fac. des Scis., Univ. Libre de Bruxelles, Belgium; R Balescu; Fac. des Scis., Univ. Libre de Bruxelles, Belgium
Журнал:
Plasma Physics and Controlled Fusion
Дата:
1987-08-01
Аннотация:
For pt. I see ibid., vol.29, no.8, pp.993-1018 (1987). The concept of clumps is used in the Tokamak turbulence theory. Using the Misguich-Balescu stochastic orbit treatment (1985), the two-point fluctuation correlation equation is studied in detail. It is shown that the Hirshman-Molvig effect (1979) has a special influence on the clumps theory: the general quasilinear diffusion regime does not exist in Tokamaks. It is found that the clumps cannot be considered only as a destabilizing mechanism ('clumps-induced instability'), the presence of Delta omega (the frequency width at fixed wavenumber) stabilizes the plasma. It is also shown that Delta omega approximately omega <sub>c</sub>> omega as a result of the Hirshman-Molvig effect on the propagator. The saturation appears as a result of the balance between the clumps and the ion Compton scattering. The fluctuation spectrum is estimated, the large k<sub>theta </sub> asymptotic form is k<sub>theta </sub><sup>-10</sup>3/.
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