Simulations of the neutral-beam-induced rotation, radial electric field, and flow shearing rate in next-step burning plasmas

Toroidal rotation of plasmas in present-day tokamaks is beneficial for increasing the stability to wall-induced MHD and appears to reduce the anomalous transport associated with micro-turbulence. This paper calculates the toroidal rotation expected from neutral beam injection in the proposed FIRE and ITER-FEAT tokamak reactors. Self-consistent burning plasmas for these tokamaks have been constructed [1] using the TRANSP plasma analysis code. Neutral beam injection has been proposed for FIRE and ITER-FEAT. The neutral-beam-induced torques are computed, and assumptions for the anomalous transport of toroidal angular momentum are used to calculate the toroidal rotation profiles. The central Mach numbers are about 3-8 %. The ratio of the rotation speed to the Alfvén speed is less than 1%. Assuming neo-classical poloidal rotation and force balance, the radial electric field and flow shearing rate are calculated. Peak shearing rates near the outboard edge are in the 10-100 krad/s range. Classification: MO (Reactor Physics and Design) 1