Common-source TLD and RADFET characterization of Co-60, Cs-137, and X-ray irradiation sources [bipolar linear ICs]

Dose rate and dose enhancement (DE) factors were measured at fifteen gamma sources at eight different laboratories using thermoluminescent dosimeters (TLDs) from two independent sources and pMOS RADFETs, respectively. Dose enhancement factors were determined by comparing the responses of RADFETs with ceramic and gold-flashed kovar lids. Dose enhancement factors measured within Pb/Al test enclosures varied from essentially 1.0 (no enhancement) very close to a Co-60 room or tunnel source up to 1.24 within an enclosed Gammacell 220. DE factors between 1.5 and 1.8 were measured within a Pb/Al box behind a 2-inch Pb brick attenuator in a Co-60 room source. Two Cs-137 sources evaluated were characterized by DE factors extending from 1.17 up to 1.3-1.4 inside the Pb/Al box. Gamma cell dose rates determined from TLDs from the Naval Surface Warfare Center (NSWC)-Crane and Sandia National Laboratories (SNL) were generally close to expected levels. Dose rates were measured in an ARACOR 4100 X-ray source using both SNL dual-dielectric RADFETs and Radiation Experiments and Monitors (REM) thick thermal oxide RADFETs.