Performance of the BGSDC integrator for computing fast ion trajectories in nuclear fusion reactors

Enthalten in
Computer Physics Communications 
Volume
264
Article Number
107876
Citation
Computer Physics Communications 264: 107876 (2021-07)
Publisher DOI
10.1016/j.cpc.2021.107876
Scopus ID
2-s2.0-85102656441
ArXiv ID
2005.07705v2
Publisher
North Holland Publ. Co./Elsevier
Modelling neutral beam injection (NBI) in fusion reactors requires computing the trajectories of large ensembles of particles. Slowing down times of up to one second combined with nanosecond time steps make these simulations computationally very costly. This paper explores the performance of BGSDC, a new numerical time stepping method, for tracking ions generated by NBI in the DIII-D and JET reactors. BGSDC is a high-order generalisation of the Boris method, combining it with spectral deferred corrections and the Generalized Minimal Residual method GMRES. Without collision modelling, where numerical drift can be quantified accurately, we find that BGSDC can deliver higher quality particle distributions than the standard Boris integrator at comparable cost or comparable distributions at lower cost. With collision models, quantifying accuracy is difficult but we show that BGSDC produces stable distributions at larger time steps than Boris.
Schlagworte
Boris integrator
DIII-D
Fast ions
JET
Neutral beam injection
Particle tracking
Spectral deferred corrections
Physics - Computational Physics
Physics - Computational Physics
Computer Science - Numerical Analysis
Mathematics - Numerical Analysis
DDC Class
004: Informatik
510: Mathematik
530: Physik