First Orbit Losses of Charged Fusion Products in Tokamak: Flux Calculation

Abstract

Technique of calculation the pitch-angle, energy and poloidal distributions of the flux of charged fusion products (CFPs) lost to the first wall of axisymmetric tokamak due to first orbit (FO) loss mechanism is developed. This technique extends the approach for evaluation the poloidal distributions of FO loss of CFPs in tokamaks proposed by [Kolesnichenko Ya.I. et al. Sov. J. Plasma Phys 2 (1976) 506]. The upgraded technique enables to calculate distributions of lost fast ions in wide class of tokamak magnetic configurations. Analytical model of the magnetic field used in this study [Yavorskij V.A. et al. Plasma Phys. Control. Fusion 43 (2001) 249] takes into account Shafranov shift, elongation, triangularity and up-down asymmetry. Usage of the drift constant of motion space allows substantial reducing the computational efforts for simulation the lost particles flux at a given point of the first wall. The developed approach is useful for simulation the pitch-angle and energy distributions of fast ions lost to the scintillator detector [Zweben S.J. et al. Nucl.Fusion 30 (1990) 1551] in present-day tokamaks [Kiptily V.G. et al. Nucl.Fusion 49 (2009) 065030] as well as for calculation of the CFP fluxes to the plasma-facing wall in future tokamak-reactors.

Keywords

• first orbit losses
• charged fusion product
• axisymmetric tokamak
• scintillator detector