Willingale, L and Mangles, SPD and Nilson, PM and Clarke, RJ and Dangor, AE and Kaluza, MC and Karsch, S and Lancaster, KL and Mori, WB and Najmudin, Z and Schreiber, J and Thomas, Alec and Wei, MS and Krushelnick, K (2006) Collimated multi-MeV ion beams from high-intensity laser interactions with underdense plasma. Physical review letters, 96 (24): 245002. ISSN 1079-7114
Abstract
A beam of multi-MeV helium ions has been observed from the interaction of a short-pulse high-intensity laser pulse with underdense helium plasma. The ion beam was found to have a maximum energy for He2+ of (40(-8)(+3)) MeV and was directional along the laser propagation path, with the highest energy ions being collimated to a cone of less than 10 degrees. 2D particle-in-cell simulations show that the ions are accelerated by a sheath electric field that is produced at the back of the gas target. This electric field is generated by transfer of laser energy to a hot electron beam, which exits the target generating large space-charge fields normal to its boundary.