MeV X Rays and Photoneutrons from Femtosecond Laser-Produced Plasmas

We demonstrate a novel method to monitor the total angular distribution of the spectrum of hard x-ray emission from a plasma generated with femtosecond laser pulses with an intensity of $5\times {10}^{18}\mathrm{W}/{\mathrm{cm}}^2$ on a solid target. Measured and calculated angular distributions of x rays show a pronounced anisotropy for MeV photon energies. We complemented the spectral information by demonstrating a $(\gamma ,n)$ nuclear reaction with a tabletop laser system.