Response curve evaluation of the RTM661/440lnc RADOS device

The RADOSRTM661/440lnc is a gamma counting device used for the radiological classification of materials. To characterize its response to isotropic photon-emitting sources across a range of energies FLUKA simulations are conducted. The simulated data is compared against a provided response curve and experimental measurements. A notable discrepancy is seen between the simulated response and the manufacturer’s response, suggesting a need to investigate the methodology used to derive this data. Furthermore, while the simulations consistently overestimate experimental measurements, a trend is observed, where the simulated response more closely resembles the measured data as the detector size is reduced, suggesting that a precise geometric model of the device is crucial for accurate simulation. In a separate analysis, the device’s six scintillation detectors are modeled individually. This confirms, that simulated values consistently exceeded measured values for all detectors, with the magnitude of the deviation varying significantly. This work serves as a starting point for validating and refining simulation
 models for such gamma counting devices.