Optimized event generator for strong-field QED simulations within the hi- framework

Probabilistic generation of photons and electron-positron pairs due to the processes of strong-field quantum electrodynamics (SFQED) is often the most resource-intensive part of the kinetic simulations required in order to model current and future experimental studies at high-intensity laser facilities. To reduce its computational demands one can exploit tabulation of the precomputed rates, time-step sub-cycling, dynamic down-sampling of particle/photon ensembles and other approaches. As the culmination of previous improvements, the method described here provides the opportunity to make the minimal possible number of rate computations per QED event. In some of our tests, this method was shown to increase performance by more than an order of magnitude. The computational routine is publicly available as a part of the open-source framework hi-chi designed as a Python-controlled toolbox for collaborative development.