Evaluation of Skyshine from an Accelerator Facility: Dependence on Distance and Angle.

Neutron skyshine from Linac Coherent Light Source II 4 GeV electron beam operation at SLAC National Accelerator Laboratory can contribute to prompt radiation exposure to the public at distances far beyond the accelerator tunnel housing. One of the shielding design requirements at SLAC is that the annual dose to a member of the public is no more than 0.05 mSv y.

Radiation Protection Around High-intensity Laser Interactions with Solid Targets.

Interaction of a high-intensity optical laser with a solid target can generate an ionizing radiation hazard in the form of high-energy "hot" electrons and bremsstrahlung, resulting from hot electrons interacting with the target itself and the surrounding target chamber. Previous studies have characterized the bremsstrahlung dose yields generated by such interactions for lasers in the range of 10 to 10 W cm using particle-in-cell code EPOCH and Monte Carlo code FLUKA. In this paper, electron measurements based on a depth-dose approach are presented for two laser intensities, which indicate a Maxwellian distribution is more suitable for estimating the hot electrons' energy distribution.

Bremsstrahlung Dose Yield for High-Intensity Short-Pulse Laser-Solid Experiments.

A bremsstrahlung source term has been developed by the Radiation Protection (RP) group at SLAC National Accelerator Laboratory for high-intensity short-pulse laser-solid experiments between 1017 and 1022 W cm-2. This source term couples the particle-in-cell plasma code EPOCH and the radiation transport code FLUKA to estimate the bremsstrahlung dose yield from laser-solid interactions. EPOCH characterizes the energy distribution, angular distribution, and laser-to-electron conversion efficiency of the hot electrons from laser-solid interactions, and FLUKA utilizes this hot electron source term to calculate a bremsstrahlung dose yield (mSv per J of laser energy on target).