Speaker
Description
BTR code, which is generally used for NBI beamlines design and optimizations, is applied to calculate the injected beam stopping in plasma, beam deposition and shine-through power in a fusion neutron source DEMO-FNS (R = 3.2m, a = 1m, k = 2, B = 5T, Eb = 500keV, PNBI ≈ 30MW). Beam-plasma model calculates the detailed beam spatial and angular distributions with account of injector and tokamak operation parameters. The cross-section fits by Janev-Suzuki are used for beam ionization, and beam power deposition in axial and normal beam planes, including shine-through power in the far wall (FW) plane are obtained for different geometries. The influence of beam size and beamlets angular distribution (focusing and divergence) is found essential. Thin, rectangular and focused beam geometries are compared. It is shown that neutral power decay aberrations in toroidal plasma target lead to power profiles asymmetry, which is high enough for tangentially injected thick and divergent beams. BTR beam model allows more precise evaluation of beam losses in plasma, shine-through power profiles and beam power and current deposition in plasma.
