We report a recent experiment where the first hard x-ray beam line, X-ray Pump Probe (XPP) instrument using the SLAC National Accelerator Laboratory's Linac Coherent Light Source (LCLS) free electron laser, was used to heat thin foils to high energy densities ~ 107 J/cm3. An intense 9 keV, 60 fs (FWHM) duration beam with energy of 2 - 4 mJ at the XPP beam line was focused using beryllium lenses to an irradiance approaching 1016 Wcm-2. Targets of 0.5 - 3.5 μm thick foils of Ag and Cu were studied using a suite of diagnostics including Fourier Domain Interferometry, energy calorimetry and grating and crystal spectrometers. The experimental details and spectroscopic results from the campaign will be described. Preliminary results indicate that the target is heated relatively uniformly to a temperature lower than 20 eV.
Laser generated protons have been used to probe the temporal and spatial evolution of megagauss magnetic fields. Grid deflectometry techniques have been applied to proton radiography to obtain precise measurements of proton beam angles caused by magnetic fields in laser produced plasmas. Data are presented in two different regimes of interactions at ultra high intensity (1020 W/cm2) where hots electrons are supposed to be responsible of the B field, and at lower intensity (1017 W/cm2) and later time where the gradients of temperature and density are responsible of the B field.