### Experimental Study on Production of Medical Nuclide 225Ac with 100 MeV Cyclotron

WANG Lei;LYU Yinlong;WANG Feng;GE Tao;LI Yaoqian;CAO Lei;FU Zhenhui

1. Research and Design Center for Cyclotron, China Institute of Atomic Energy, Beijing 102413, China
• Online:2021-06-20 Published:2021-06-20

### 100 MeV回旋加速器生产医用225Ac核素的实验研究

1. 中国原子能科学研究院 回旋加速器研究设计中心，北京102413

Abstract: The radionuclide production experiment was conducted at the 100 MeV cyclotron at China Institute of Atomic Energy. Fluka code was used to simulate the isotope activities of 224-228Ac produced by proton beam irradiation on ThO2 powder target with different thicknesses. The variation of yield with thickness of 1, 5 and 10 mm ThO2 targets was studied, and the target with 5 mm thickness was selected according to the law of yield variation and cooling condition. A target system for the irradiation of ThO2 powder target was designed, and the production of 225Ac nuclide with low current intensity was carried out. The functions of indirect measurement of proton beam intensity, real time monitoring of target temperature and compressed air cooling of target were realized, ensuring the safety of irradiated targets. After irradiation, ThO2 target was chemically treated and 225Ac was extracted. After 225Ac and 221Fr reached the decay equilibrium, the γ of 221Fr decay with 218 keV was measured by γ spectrometer. The activity of 225Ac at the end of bombardment is 2.29×107 Bq and the yield is 2.39×105 Bq/(μA·h).