Radiating electron source generation in ultraintense laser-foil interactions

Abstract

A radiating electron source is shown to be created by a laser pulse (with intensity of 10 23 W/cm 2 and duration equal to 30 fs) interacting with a near-critical density plasma. It is shown that the back radiation reaction resulting from high energy synchrotron radiation tends to counteract the action of the ponderomotive force. This enhances the collective dynamics of the radiating electrons in the highest field areas, resulting in the production of a compact radiation source (containing 80% of the synchrotron radiation emission), with an energy on the order of tens of MeV over the laser pulse duration. These phenomena are investigated using a QED-particle-in-cell code, and compared with a kinetic model accounting for the radiation reaction force in the electron distribution function. The results shed new light on electron-photon sources at ultra-high laser intensities and could be tested on future laser facilities.

Modelling the effects of the radiation reaction force on the interaction of thin foils with ultra-intense laser fields

“…Comparison with electron spectra obtained from simulations, however, indicates that whilst the Maxwell Juttner distribution is a reasonable approximation (further details are provided in the Appendix), it overestimates the electron temperature. To account for this, we introduce a scaling function analogous to that described in reference [37], which describes the cooling of the electrons.…”