Benchmarking relativistic PIC collision operators against full relativistic transport theory

Benchmark and validate relativistic binary Monte Carlo Coulomb collision operators used in particle-in-cell simulations against the full relativistic extensions of test-particle relaxation rates and fluid transport coefficients, in order to establish their accuracy across relativistic temperatures and energies.

Background

Several relativistic extensions of the Takizuka-Abe collision algorithm exist for PIC codes, intended to handle relativistic temperatures and energetic particles. While nonrelativistic PIC collisions have been thoroughly validated against classical test-particle relaxation rates and fluid transport coefficients, the relativistic counterparts were derived only recently.

The authors explicitly note that existing relativistic collision algorithms have not yet been benchmarked against the full relativistic theoretical predictions, identifying the need for systematic validation to provide the same level of theoretical grounding achieved in the nonrelativistic case.