Control of Alpha-Particle Transport by Ion Cyclotron Resonance Heating

Control of radial alpha-particle transport by using ion cyclotron range of frequency (ICRF) waves is investigated in a large-aspect-ratio tokamak geometry. Spatially inhomogeneous ICRF wave energy with properly selected frequencies and wave numbers can induce fast convective transports of alpha particles at the speed of order v_alpha ∼ (P_RF/n_α∈₀)ρ_p, where P_RF is the ICRF wave power density, n_α is the alpha-particle density, ∈₀ is the alpha-particle birth energy, and ρ_p is the poloidal gyroradius of alpha particles at the birth energy. Application to International Thermonuclear Experimental Reactor (ITER) plasma is studied and possible antenna designs to control alpha-particle flux are discussed.