Speaker
Description
I will start with a brief introduction summarizing my view of what has already been learnt about particle acceleration in both astrophysical settings and in laser-plasma interactions using the test-particle approach. I will then present some recent results on test-particle acceleration at relativistic shock fronts using both analytical and Monte-Carlo techniques [1,2,3]. Contrary to previous expections, these suggest that, in the relativistic regime, perpendicular shocks are just as efficient as parallel shocks. They also reveal that large-scale structure in the unshocked plasma may lead to a significant enhancement of the acceleration efficiency and a hardening of the accelerated particle spectrum in localised regions.
References
[1] Giacinti, G., Kirk, J.G., Astrophysical Journal 863, 18 (2018)
[2] Kirk, J.G., Reville B., Huang Z.Q., Monthly Notices of the Royal Astronomical Society 509, 1022 (2022)
[3] Huang, Z-Q., Reville B., Kirk, J.G., Giacinti, G., Monthly Notices of the Royal Astronomical Society 522, 4959 (2023)
