Alyssa Prinz

TOP-OFF INJECTION AND HIGHER CURRENTS AT THE STANFORD SYNCHROTRON RADIATION LIGHTSOURCE

Abstract The Stanford Synchrotron Radiation Lightsource (SSRL) at the SLAC National Accelerator Laboratory (SLAC) is currently working on increasing its stored current from originally 100 to 500 mA. SSRL worked with the SLAC Radiation Protection Department on mitigating the possible radiological hazards from these upgrades. This paper describes the related analyses, new safety systems, and beam tests. The top-off injection mode (injection with beamline stoppers open) is essential for operation at high currents. The radiological consequences of various situations were analyzed, a new Beam Containment System (BCS) was implemented, and radiation surveys were performed during tests. Since March 2010, all beamlines have been operating in top-off mode. Operation with higher beam currents was also analyzed for radiological hazards, and a new Beamline BCS was installed. The storage ring is now operating with 200 mA during user runs, and tests are ongoing with higher beam currents. Soon the power of the injection current will also be raised from 1.5 W at present to 5 W maximal.

Shielding Calculations for the Hard X-Rays Generated by LCLS MEC Laser System

Abstract The Linac Coherent Light Source Matter in Extreme Conditions (MEC) Instrument is an X-ray instrument that will be able to create and diagnose high-energy-density matter. The MEC laser system can generate hard X-rays due to the interaction of the laser and the plasma. This paper summarizes results of the shielding calculations performed to evaluate the radiation hazards induced by this hard-X-ray source with the Monte Carlo code FLUKA. The dose rates and photon spectra due to this X-ray source are calculated at different locations with different shielding. The influence of the electron temperature on the source terms and the shielding effectiveness was also investigated.