Wakefield acceleration and betatron radiation driven by linearly polarized Laguerre-Gaussian orbital angular momentum laser pulses

In this work, we report on the first results of wakefield accelerated electrons by ultra-intense linearly polarized Laguerre-Gaussian orbital angular momentum (OAM) modes. These modes, generated after compression in the VEGA2 200TW Titanium:Sapphire laser system at the Centro de Láseres Pulsados (CLPU) in Spain used new novel off-axis spiral phase mirrors to convert the flat top laser mode to high purity Laguerre-Gaussian LG10, LG20 and LG-10 beams with intensities of over 10¹⁸Wcm^-2 . The difference in electron and betatron divergence, flux, and spectrum when compared to the standard TEM00 mode will be presented. Additionally, the generation of strong axial magnetic fields in these new interactions will be discussed. These results will be compared to simple analytic scaling models and simulations using the 3D PIC code EPOCH.

This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) research Grant Number RGPIN-2014-05736, and the Spanish Ministerio de Ciencia, Innovación y Universidades (PALMA project FIS2016-81056-R) and Junta de Castilla y León project CLP087U16.