Comparative evaluation of two methods for 172Tm production in nuclear reactors

A comparative evaluation of two methods for the production of Tm-172 in nuclear reactors is carried out. They are respectively based on two chains of double neutron capture reactions, Er-170(n, gamma)Er-171(n, gamma)Er-172(beta(-))Tm-172 and Er-170(n, gamma)Er-171(beta(-))Tm-171(n, gamma)Tm-172, and a chain of triple neutron capture: Tm-169(n, gamma)Tm-170(n, gamma)Tm-71(n, gamma)Tm-172. Theoretical considerations with respect to both ways of production are formulated and the mathematical equation are solved. Experiments of irradiation of Er2O3 and Tm2O3 were performed. Advantages and drawbacks of both methods are discussed.