| This work focused on using thermoluminescent dosimeters (TLDs) to measure the doses from two x-ray sources, a CT scanner and a linear accelerator (linac). In addition ion chambers were used to determine the isodose contours from the operation of the linac. 1mm x 1mm x 1mm TLD-100 microcubes were placed in a Lawrence Livermore National Laboratory (LLNL) torso phantom and irradiated using a Toshiba Aquilion One 320-Slice CT Scanner. Different thicknesses of shielding composed of antimony and bismuth powder suspended in an ethylene copolymer were used to shield the phantom and the dose reduction was measured. The dose reduction ranged from 25% to 50% depending on the thickness of the shield. TLD-700s were attached to a LLNL phantom to measure the dose from a 3 and 6MeV accelerator. The dose to a potential stowaway was measured to be 6.3+/-2.7mrem and 16.3+/-2.8mrem, while the dose to the driver was 5.5+/-0.5 and 17.0+/-1.2mrem, respectively. The 2mr hr -1 line was measured at 22ft when operating at 3MeV and 35ft when operating at 6MeV. |
