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arXiv · 1708.04511

Signatures of quantum effects on radiation reaction in laser -- electron-beam collisions

C. P. Ridgers·T. G. Blackburn·D. Del Sorbo·L. E. Bradley·C. D. Baird·S. P. D. Mangles·P. McKenna·M. Marklund·C. D. Murphy·A. G. R. Thomas
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Abstract

Two signatures of quantum effects on radiation reaction in the collision of a ~GeV electron-beam with a high-intensity (>3x10^20W/cm^2) laser-pulse have been considered. We show that the decrease in the average energy of the electron-beam may be used to measure the Gaunt factor g for synchrotron emission. We derive an equation for the evolution of the variance in the energy of the electron-beam in the quantum regime, i.e. quantum efficiency parameter eta > 0.1$. We show that the evolution of the variance may be used as a direct measure of the quantum stochasticity of the radiation reaction and determine the parameter regime where this is observable. For example, stochastic emission results in a 25% increase in the standard deviation of the energy spectrum of a GeV electron beam, 1 fs after it collides with a laser pulse of intensity 10^21 W/cm^2. This effect should therefore be measurable using current high-intensity laser systems.

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C. P. Ridgers, T. G. Blackburn, D. Del Sorbo, L. E. Bradley, C. D. Baird, S. P. D. Mangles, P. McKenna, M. Marklund, C. D. Murphy, A. G. R. Thomas. 2017-07-17. Signatures of quantum effects on radiation reaction in laser -- electron-beam collisions. https://doi.org/10.1017/s0022377817000642

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