CdTe Sensor Configurations for Robot Assisted Photon Counting Gamma Camera

In this work, different Cadmium Telluride (CdTe) sensor configurations are assessed for the usage in a robot assisted portable gamma camera. In the first part, four CdTe sensors, with thickness of 0.45 mm, 1 mm, 2 mm and 3 mm and pixel sizes of 55 mu m and 110 mu m, are investigated regarding their spectroscopic performance. The photon counting detector Timepixl is hereby used. The 3 mm CdTe sensor shows increase in count rate up to a factor of 1.25 compared to a 2 mm CdTe sensor, 1.84 compared to a 1 mm CdTe sensor and up to 2.71 compared to a 0.45 mm CdTe sensor in the case of Cs-137. In the second part, the 3 mm CdTe sensor was implemented in a commercially available gamma camera, the iPIX. The system was integrated in the bomb disposal robot and tested in different scenarios. The integrated 3 mm CdTe detector measured 21.5 counts per second emitting from a Co-60 source with an activity of 2.8 +/- 0.07 Gbq in 20 meters distance in an open environment. The acquisition time was 116 seconds. The angular resolution was sufficient for the user to localize the radioactive isotope inside the test structure.