Radioisotope finding method is required to prevent terrorist acts using radioactive source(s) and to find lost or stolen radiation source(s). For operators’ safety, it is desirable to use an unmanned system with remote operation. Therefore, we are developing a prototype system using a 4π gamma imager and a 3D-LiDAR mounted on an unmanned vehicle for simultaneously performing gamma-ray imaging and recognition of surrounding structures. Finding of a high-intensity 137Cs gamma point source located at 70 m square field was demonstrated experimentally based on fusion data between 4π gamma images and 3D-LiDAR-SLAM obtained by the prototype system.
