Hot Electron and Pair Production from the Texas Petawatt Laser   Irradiating Thick Gold Targets
  We present data for relativistic hot electron production by the Texas Petawatt Laser irradiating solid Au targets with thickness between 1 and 4 mm. The experiment was performed at the short focus target chamber TC1 in July 2011, with laser energies around 50 J. We measured hot electron spectra out to 50 MeV which show a narrow peak around 10 - 20 MeV plus high energy exponential tail. The hot electron spectral shape differs from those reported for other PW lasers. We did not observe direct evidence of positron production above background. 
Devin Taylor, Edison Liang, Taylor Clarke, Alexander Henderson, Petr   Chaguine, Xin Wang, Gilliss Dyer, Kristina Serratto, ...
physics.plasm-ph astro-ph.HE physics.acc-ph physics.med-ph