A new position recording system for the partial-body counter at KIT

The position of detectors used for partial-body counters relative to a measured person has considerable influence on the counting efficiency of low-energy photon emitters. To minimise reading errors and enhance reproducibility of position data, an electronic position recording system was installed in the partial-body counter chamber at KIT. Phoswich detectors have been equipped with electronic sensors to determine the position and axes of the detectors. Additionally, a laser measurement system determines the position of arbitrary landmarks, e.g. point sources, anatomical features of phantoms and test persons. A network interface enables the reading of the position data on any connected computer. The system was successfully used to validate Monte Carlo simulations of partial-body counting scenarios for the numerical determination of counting efficiencies.