Heavy-Ion Production of Theranostic $^{\mathrm{149}}$Tb for Potential Medical Applications*

Theranostics is an emerging field of nuclear medicine that uses radioisotopes to~simultaneously image and treat disease. One possible theranostic isotope, $^{\mathrm{149}}$Tb, performs therapeutic and diagnostic functions with branches of alpha and positron decay modes. As a very proton-rich nucleus, $^{\mathrm{149}}$Tb (t$_{\mathrm{1/2\thinspace }}=$ 4.12 h) is restricted to accelerator production, harvesting and clinical work in close proximity. It has only been produced for clinical tests by a light-ion spallation reaction at a high-energy nuclear physics facility to date.~ We propose an alternate production method using a heavy-ion reaction close to the Coulomb barrier. In this study $^{\mathrm{89}}$Y($^{\mathrm{63}}$Cu,x)$^{\mathrm{149}}$X was studied as an indirect production pathway for all n$=$149 isobars. The preliminary physical yields for $^{\mathrm{149}}$Tb and other~reaction~products measured by offline gamma spectroscopy are compared to the PACE4 fusion-evaporation predictions. A near symmetric fission yield is also observed.~ This method has demonstrated significant radiochemical purity compared to spallation production methods, which makes for easier radiochemical separation.