Room: Exhibit Hall
Purpose: The aim of this study was to compare the performance of the direct ion storage (DIS) dosimeters to the commonly used optically stimulated luminescence (OSL) dosimeters. The advantages, limits, practical considerations and potential applications were also compared.
Methods: A simple mathematical model to account for beam energy and incident angles was utilized to estimate deep dose equivalent (DDE) base on exposure measurements. Validation testing consisted of the irradiation of 2 types of DIS dosimeters, an OSL-type dosimeter, and a Ludlum 9DP ion chamber survey meter utilizing a Cs-137 radiation source and fluoroscopic C-arm. Measurements were taken with and without backscattering material immediately behind the devices. Effects on dosimeter performance due to a clinical MRI environment were also evaluated. Lastly, the DIS dosimeters were worn by radiation workers side-by-side with OSL dosimeters for two months.
Results: The overall differences from calculated expected values were 7.8%, 9.8% and 10.9% lower, respectively, for two types of DIS dosimeters and an OSL-type dosimeter. -1.0%, +0.4% and +15.9% differences, respectively, were observed for two types of DIS dosimeters and OSL dosimeter due to the presence of backscattering material. -5.0% and -8.8% differences, respectively, were observed in the performance two types of DIS dosimeters due to magnetic field exposure.
Conclusion: The results demonstrated good agreement between the doses recorded by the DIS and the OSL dosimeters. Additionally, the DIS dosimeters were unaffected by the presence of backscatter. Conversely, preliminary data collected on OSL dosimeter readings appears to indicate the dependence on backscatter. Magnetic field exposed DIS dosimeters showed negligible effects on dose measurements. Overall, DIS dosimeters appear to provide an accurate and efficient way to monitor and manage occupational dose.