Radiations of 93Y and 94Y and half-lives of 93Sr and 94Sr☆

摘要: Abstract The radiations of 93Y and 94Y have been examined by β-ray spectrometry γ-ray scintillation spectrometry. decays about 90 per cent a 2·89±0·02-MeV β-transition to the ground state 93Zr; spectrum 2·89 MeV group has unique first-forbidden shape γ-rays energies 0·267, 0·49, 0·935, 1·15, 1·20, 1·42, 1·89-1·91, 2·14-2·18 ∼2·43 accompany remaining 10 disintegrations. On basis γ-γ coincidence measurements, these fitted partial decay scheme involving levels in 93Zr at 1·89, 2·18 MeV. complex β-spectrum maximum energy 5·0 ± 0·2 MeV; highest-energy corresponds transition 94Zr. lower-energy β-transitions are accompanied 0·56, 0·92, 1·13, 1·65, 1·90, 2·13, 2·84 3·53 MeV, plus unresolved groups 2·57 3·06 half-lives 93Sr 94Sr, measured experiments periodic chemical separations from fission-product strontium, 8·2 0·0·8 min 1·3 min, respectively. 10·25 0·10 hr 20 1 A search made for isomerism 93Y. Measurements on yttrium grown strontium shown no definite evidence an isomer with half-line range 30 sec 3 hr. yield fission 235U water-moderated “pile” neutrons is (6·1 0·6) cent.