Betatron motion in a laser wakefield accelerator using a customized dispersion-free particle-in-cell field solver
ORAL
Abstract
When laser fields overlap electrons located within the wake of a laser wakefield accelerator (LWFA), these electrons can attain large energies due to the combined effects of the accelerating wakefields and direct laser acceleration (DLA). Standard particle-in-cell (PIC) techniques (e.g., Yee field solver and Boris push) can lead to numerical errors in electron trajectories and energies. A customized finite-difference field solver has been developed that eliminates dispersion errors in the phase velocity of light waves and errors in the Lorentz force due to the staggering in time of electric and magnetic fields. In this work we examine the collective behavior of the accelerated electron bunch in real space and phasespace with various PIC field solvers. Comparison is made to experiment, showing better agreement when using the customized field solver. The LWFA and DLA mechanisms contribute similar amounts of energy to the highest-energy electrons. Finally, the equation of motion for accelerated electrons is numerically integrated with and without time-stagger error terms, confirming the PIC results and providing a tool for investigating sustained betatron resonance.
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Publication: F. Li, K. G. Miller, X. Xu, F. S. Tsung, V. K. Decyk, W. An, R. A. Fonseca and W. B. Mori, "A new field solver for modeling of relativistic particle–laser interactions using the particle-in-cell algorithm," Computer Physics Communications 258, 107580 (2021).
Presenters
Kyle G Miller
Laboratory for Laser Energetics, University of Rochester, University of California, Los Angeles
Authors
Kyle G Miller
Laboratory for Laser Energetics, University of Rochester, University of California, Los Angeles
Fei Li
University of California, Los Angeles
Xinlu Xu
SLAC - Natl Accelerator Lab
Frank S Tsung
University of California, Los Angeles
Viktor K Decyk
University of California, Los Angeles
Warren B Mori
University of California, Los Angeles, Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA
