Novel Gamma Tracker for Rapid Radiation Direction Detection for UAV Drone Use

The localization of radioactivity is an increasing topic of interest, both in the field of nuclear medicine and for environmental monitoring. We developed a gamma tracker prototype that is a small and handy object that can identify the direction of a radioactive source; it consists in more than one scintillation detecting elements with a cylindrical symmetry (40 mm height and 25 mm large) coupled with a position sensitive photo detecting matrix of SiPM; external crystals (LYSO, attenuation coefficient at 511 keV=0.86 cm-1) surround an internal one acting like an active collimation that shield the central detector (LaBr3:Ce or GAGG) and giving information about the radioactive source position. We firstly investigated spectrometric characteristics of the prototype detecting elements, irradiating the crystals with collimated 133Ba and 57Co sources; LaBr3:Ce crystal show an excellent Energy Resolution (ER) (7.2% at 122 keV), while external detectors show a good shielding property and a good ER, adequate to reduce the diffuse radiation background. Finally, we explored the properties of whole detecting system (scintillating crystals + SiPM matrix); we found that the spectrometric properties are not compromised by the crystals coupling with the photo detecting means and that the identification of the radioactive source direction is possible with an accuracy of 2°.