Production of ¹⁴⁹Terbium for Medical Diagnostics and Treatment

Long-lived radioactive isotopes are used for applications such as cancer diagnostics and treatment. These isotopes must typically satisfy several criteria to be suitable – such as having an appropriate half-life and specific decay properties. We produced ¹⁴⁹Tb (t_1/2 = 4.1 hrs) by an indirect heavy ion reaction, ¹⁴¹Pr(¹⁴N, 6n)¹⁴⁹Dy, which subsequently decayed to ¹⁴⁹Tb. A 10 MeV/n ¹⁴N beam was accelerated by the K150 Cyclotron at Texas A&M University’s Cyclotron Institute and irradiated a Pr₆O₁₁ target. The long-lived products produced in this reaction were identified by gamma-rays with a high-purity germanium detector set to measure off-line in one-hour increments over 22 hours. This information was used to measure the original activity of ¹⁴⁹Tb at the end of beam and to calculate the reaction cross section. The observed cross section is significantly lower than the theoretical cross section, although this difference has been seen previously in the literature.