Fig. 6: Effect of pre-plasma on the electron temperature in the PIC simulation.
a Bulk-electron temperature Te at 1.8 ps delay versus the initial surface-density scalelength of the target L0 (markers). The dashed line is an exponential fit to the data and serve as a guide for the eye. b Electron-velocity distribution in the laser-propagation direction to the time of the maximum return current at 20 fs delay. The blue and orange line show the electron-velocity distribution of L0 = 0 nm and 250 nm, respectively.
