Production of curie amounts of caesium-127 and caesium-129 for medical use

Reports the spallation yields of 127 Cs and 129 Cs from barium and lanthanum targets irradiated at the Space Radiation Effects Laboratory, NASA. The cross-sections for 127 Cs and 129 Cs production with 600 MeV protons are 18 mb and 17 mb, respectively, with a barium target, and 59 mb and 35 mb, respectively, with a lanthanum target. These cross-sections indicate that irradiation of a lanthanum target at any of the high-current meson facilities now being constructed would produce 8 Ci h -1 of 127 Cs and 0.9 Ci h -1 of 129 Cs. A three hour irradiation of a lanthanum target at a high flux machine would result in enough caesium (6 Ci after separation and transportation) to administer heart imaging doses to more than a thousand patients.