Development of an omnidirectional detector for beta and gamma-ray imaging with fractal geometry

Radiation imaging is useful in various fields where the location of radiation sources needs to be identified. Especially in environments where radiation sources are distributed in three dimensions and difficult to locate, the development of a small imaging sensor that can detect radiation in the 4π direction will have a significant impact on the progress of work. We have developed a radiation detector with a fractal geometry. This is a unit of tetrahedral radiation sensors, 16 sensors are arranged in a Sierpinski tetrahedron shape, and the space between the sensors is filled with heavy metals. The count rates of the individual sensors make it possible to determine the direction of radiation incidence. Furthermore, since there is no external shielding, the distribution of charged particles, such as beta rays, can also be measured. We have analyzed the response of the Sierpinski radiation detector with respect to the incident direction of γ and β rays and compared it with experimental results to understand the sensitivity characteristics.