Speaker
Description
In this work, we show an alternative approach for calculating energy spectra of particles generated via fast ions in magnetized plasmas reacting with a finite temperature bulk. While numerical methods account for all degrees of freedom involved, recently developed analytical methods [1-3] disregard the temperature of the bulk plasma in favor of faster calculations. Here, we still make use of the beam-target approximation for the nuclear reaction, to maintain our model analytical, but retain energy and momentum of the target particles in the energy and momentum conservation laws. This is achieved by using center-of-mass velocity coordinates and noting that the center-of-mass velocity $\bf{v}_\text{CM}$ and the relative velocity $\bf{v}_\text{rel}$ are highly correlated in the gyro-angle coordinate $\Gamma$ describing the azimuthal rotation about the local magnetic field. The model remains analytical, as no Monte Carlo sampling of either of the reactant distributions is required, at the cost of some discrepancy which we quantify in terms of spectral moments relative difference with full Monte Carlo simulations [4,5].
[1] Valentini A. et al 2024 Nuclear Fusion 65 026001
[2] Valentini A. et al 2024 Review of Scientific Instruments 95 083551
[3] Valentini A. et al 2025 Nuclear Fusion 65 046031
[4] Eriksson J., Conroy S., Andersson Sundén E. and Hellesen C. 2016 Computer Physics Communications 199
40–46
[5] Nocente M., Källne J., Salewski M., Tardocchi M. and Gorini G. 2015 Nuclear Fusion 55 123009