Lateral Electron Transport in High-Intensity Laser-Irradiated Foils Diagnosed by Ion Emission

Abstract

An experimental investigation of lateral electron transport in thin metallic foil targets irradiated by ultraintense ($\ge {10}^{19}\mathrm{W}/{\mathrm{cm}}^2$) laser pulses is reported. Two-dimensional spatially resolved ion emission measurements are used to quantify electric-field generation resulting from electron transport. The measurement of large electric fields ($\sim 0.1\mathrm{TV}/\mathrm{m}$) millimeters from the laser focus reveals that lateral energy transport continues long after the laser pulse has decayed. Numerical simulations confirm a very strong enhancement of electron density and electric field at the edges of the target.