Eur. Phys. J. D (2012) 66: 298
https://doi.org/10.1140/epjd/e2012-30253-7

Regular Article

Fast electron penetration in laser-irradiated solids

¹ Department of Physics, Kohat University of Science and Technology, 26000 Kohat, Pakistan
² Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, BT7 1NN Belfast, UK
³ Juelich Supercomputing Centre, Institute for Advanced Simulation, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
⁴ Central Laser Facility, Rutherford Appleton Laboratory, Chilton, OX11 0 QX Didcot, UK

^a e-mail: d.riley@qub.ac.uk

Received: 17 April 2012
Received in final form: 17 September 2012
Published online: 4 December 2012

Abstract

In this letter we present data comparing the yield of Cu K-α radiation for foils of differing thickness irradiated with a Ti:Sapphire laser generating 40 fs pulses at 800 nm and incident at 45°. At tight focus, the yields for all thicknesses are similar, whilst away from best focus there are clear differences. We discuss the origin of these similarities and differences in terms of the penetration of fast electrons into the foil and the possible importance of refluxing of fast electrons as they reach the non-irradiated side of the foil.