¹²⁹Cs production via the ¹²⁷I(α,2n) ¹²⁹Cs reaction and its preparation as a radiopharmaceutical

Abstract

The production of carrier-free 129Cs for medical use by the (α,2n) reaction on thick sodium iodide and iodine targets is reported. The yield curve for the 127I(α,2n) 129Cs reaction on thick single crystals of sodium iodide was determined at incident energies of 16-40 MeV. The maximum yield of 0.7 mCi/µA-h was obtained above about 36 MeV. Procedures for reducing contaminants at the bombardment of sodium iodide or iodine targets are described. Ge(Li) spectra of 129Cs are presented showing previously unreported γ-energies at 266.9, 282.4, 492.6, 533.9, 624.3 and 864.7 keV. The half-life of 129Cs was measured to be 32.9 ± 0.2 hours. Also presented are the radiopharmaceutical procedures used to prepare the isotope for in vivo use.