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arXiv · 1909.06059

Effective production of gammas, positrons, and photonuclear particles from optimized electron acceleration by short laser pulses in low-density targets

M. G. Lobok·A. V. Brantov·V. Yu. Bychenkov
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Abstract

Electron acceleration has been optimized based on 3D PIC simulations of a short laser pulse interacting with low-density plasma targets to find the pulse propagation regime that maximizes the charge of high-energy electron bunches. This regime corresponds to laser pulse propagation in a self-trapping mode where the diffraction divergence is balanced by the relativistic nonlinearity such that relativistic self-focusing on the axis does not happen and the laser beam radius stays unchanged during pulse propagation in a plasma over many Rayleigh lengths. Such a regime occurs for a near-critical density if the pulse length considerably exceeds both the plasma wavelength and the pulse width. Electron acceleration occurs in a traveling cavity filled with a high-frequency laser field and a longitudinal electrostatic single-cycle field ("self-trapping regime"). Monte Carlo simulations demonstrated a high electron yield that allows an efficient production of gamma radiation, electron--positron pairs, neutrons, and even pions from a catcher-target.

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M. G. Lobok, A. V. Brantov, V. Yu. Bychenkov. 2019-09-13. Effective production of gammas, positrons, and photonuclear particles from optimized electron acceleration by short laser pulses in low-density targets. https://doi.org/10.1063/1.5125968

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