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(TH/1) Generation and Sustainment of Plasma Rotation by ICRF Heating

F. W. Perkins¹⁾, R. White¹⁾³⁾, P. T. Bonoli²⁾, V. S. Chan^3)
 
1) Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey USA
²⁾ Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts
³⁾ General Atomics, P.O. Box 451, San Diego, California USA

Abstract.  A mechanism is proposed and evaluated for driving rotation in tokamak plasmas by minority ion-cyclotron heating, even though this process introduces negligible angular momentum. The mechanism has two elements: First, angular momentum transport is governed by a diffusion equation with a non-slip boundary condition at the separatrix. Second, Monte-Carlo calculations show that energized particles will provide a torque density source which has a zero volume integral but separated positive and negative regions. With such a source, a solution of the diffusion equation predicts the on-axis rotation frequency $\Omega$ to be $\Omega$ = (4q_maxWJ^*)eBR³a²n_e(2$\pi$)²)^-1($\tau_{\mathrm{M}}^{}$/$\tau_{\mathrm{E}}^{}$) where | J^*| $\approx$ 5 - 10 is a nondimensional rotation frequency calculated by the Monte-Carlo ORBIT code. Overall, agreement with experiment is good, when the resonance is on the low-field-side of the magnetic axis. The rotation becomes more counter-current and reverses sign on the high field side for a no-slip boundary. The velocity shear layer position is controllable and of sufficient magnitude to affect microinstabilities.

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