The half-lives for 24Na, 72Ga and 140La

Abstract

THE HALF-LIVES of 2'*Na, 72Ga and 14°La were determined by counting neutrons from D(7. n) and Be 0', n) reactions. The radionuclide samples were encapsulated in aluminum shells to form the gamma-ray emitting core of spherical photoneutron sources. Half-lives were determined by unfolding the activation and decay of 56Mn in a manganese sulfate bath. Half-lives were determined to be 15.010 + 0.028, 13.945 + 0.005 and 40.232 + 0.067 hr for 2'*Na, 72Ga and 14°La, respectively. The value for 72Ga is 1% lower than previously published values.