Radioisotope Production through Accelerators in Crystalline Targets

The production techniques of radioisotopes for medical purposes is a valuable and important field in nuclear medicine. In particular, the expensive cost of the prime materials for the production via cyclotron obliges the search for new solutions to enhance the production rate with minor upgrades of the current instrumentation. Oriented ordered structure can modify particle trajectories inside a medium leading to a sensible variation of the interaction rate with atomic nuclei. Under specific orientations of the target with respect to the incident beam, the probability of inelastic interaction with nuclei can be enhanced with respect to the standard rate. This effect is called anti-channeling and leads to an increase of the radioisotope production yield. A dedicated set of experimental measurements were carried out at the CN accelerator of the INFN Legnaro Laboratories to investigate nuclear reactions under channeling experiments. In particular, the production of the Arsenic-74 radioisotope through a proton beam delivered to a natural single-crystal Germanium target was monitored via γ-spectroscopy of the prompt γ-rays upon de-excitation of produced nuclei, in order to quantify the production rate variation as a function of the incident angle.