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arXiv · 1510.05764

Spontaneous emergence of non-planar electron orbits during direct laser acceleration by a linearly polarized laser pulse

A. V. Arefiev·V. N. Khudik·A. P. L. Robinson·G. Shvets·L. Willingale
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Abstract

An electron irradiated by a linearly polarized relativistic intensity laser pulse in a cylindrical plasma channel can gain significant energy from the pulse. The laser electric and magnetic fields drive electron oscillations in a plane making it natural to expect the electron trajectory to be flat. We show that strong modulations of the relativistic $γ$-factor associated with the energy enhancement cause the free oscillations perpendicular to the plane of the driven motion to become unstable. As a consequence, out of plane displacements grow to become comparable to the amplitude of the driven oscillations and the electron trajectory becomes essentially three-dimensional, even if at an early stage of the acceleration it was flat. The development of the instability profoundly affects the x-ray emission, causing considerable divergence of the radiation perpendicular to the plane of the driven oscillations, while also reducing the overall emitted energy.

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A. V. Arefiev, V. N. Khudik, A. P. L. Robinson, G. Shvets, L. Willingale. 2015-10-20. Spontaneous emergence of non-planar electron orbits during direct laser acceleration by a linearly polarized laser pulse. https://doi.org/10.1063/1.4942036

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