Research on the production of 99mTc and 99Mo using multi-layer targets at APEP

Abstract

One of the most effective methods for producing radioisotopes aimed at Nuclear Medicine applications, such as 99mTc and 99Mo, is to use a compact proton accelerator located near hospitals. Target utilization efficiency is a critical factor in the production of these isotopes, through the 100Mo(p, 2n)99mTc and 100Mo(p, pn)99Mo nuclear reaction routes. To maximize the utilization efficiency, a multi-layer target structure was developed aimed at achieving a high radionuclidic purity (RNP) level. The yield and RNP of different target structures were calculated and compared by using FLUKA code, and benchmark experiments were conducted using a proton beam at the China Spallation Neutron Source (CSNS) Associated Proton Experimental Platform (APEP). Results showed that the multi-layer target structure has the potential to significantly reduce production costs compared to a single-layer target. The multi-layer target structure is being adopted for the production of both 99mTc and 99Mo at APEP, with an expected 99mTc yield of up to 60 MBq enough for preclinical studies after 100Mo target being irradiated for about 2 h at a beam intensity of 62.5 μA.