D P Higginson, A Link, H Sawada, S C Wilks, T Bartal, S Chawla, C D Chen, K A Flippo, L C Jarrott, M H Key, H S McLean, P K Patel, F Pérez, M S Wei, F N Beg
The consequences of small scale-length precursor plasmas on high-intensity laser-driven relativistic electrons are studied via experiments and simulations. Longer scale-length plasmas are shown to dramatically increase the efficiency of electron acceleration, yet, if too long, they reduce the coupling of these electrons into the solid target. Evidence for the existence of an optimal plasma scale-length is presented and estimated to be from 1 to 5μm. Experiments on the Trident laser (I=5×10(19)W/cm(2)) diagnosed via Kα emission from Cu wires attached to Au cones are quantitively reproduced using 2D particle-in-cell simulations that capture the full temporal and spatial scale of the nonlinear laser interaction and electron transport...
December 2015: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics