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arXiv · 1410.8491

Temporal resolution criterion for correctly simulating relativistic electron motion in a high-intensity laser field

Alexey V. Arefiev·Ginevra E. Cochran·Douglass W. Schumacher·Alexander P. L. Robinson·Guangye Chen
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Abstract

Particle-in-cell codes are now standard tools for studying ultra-intense laser-plasma interactions. Motivated by direct laser acceleration of electrons in sub-critical plasmas, we examine temporal resolution requirements that must be satisfied to accurately calculate electron dynamics in strong laser fields. Using the motion of a single electron in a perfect plane electromagnetic wave as a test problem, we show surprising deterioration of the numerical accuracy with increasing wave amplitude $a_0$ for a given time-step. We go on to show analytically that the time-step must be significantly less than $λ/c a_ 0$ to achieve good accuracy. We thus propose adaptive electron sub-cycling as an efficient remedy.

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Alexey V. Arefiev, Ginevra E. Cochran, Douglass W. Schumacher, Alexander P. L. Robinson, Guangye Chen. 2014-11-11. Temporal resolution criterion for correctly simulating relativistic electron motion in a high-intensity laser field. https://doi.org/10.1063/1.4905523

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