Allowed electron-capture branches in the decay of 34mCl

Abstract

The decay of 34mCl has been studied with 36 and 100 cm3 Ge(Li) detectors and with a high-resolution large volume Ge(Li)-NaI(Tl) Compton-suppression spectrometer. The 34mCl activity was produced with the reaction 24Mg(12C, pn)34Cl at E(12C) = 35 MeV by bombarding thick natural Mg targets. The half-life was measured to be . Nine γ-ray transitions were observed including four γ-rays not seen previously. The measured γ-ray intensities determine new electron-capture branches of (0.030 ± 0.006) % and (0.032 ± 0.003) % to 34S levels at 4.69 and 4.88 MeV with log ft values of 5.48 ± 0.08 and 5.26 ±0.04, respectively. These log ft values imply allowed transitions and are consistent with the known Jπ values of Jπ = 4+ and 3+ of the 4.69 and 4.88 MeV levels, respectively. A lower limit of log ft 6.9 is obtained for the allowed electron-capture branch to the Jπ = 2+, 4.89 MeV level. Other previously observed decay branches have been confirmed. Since the decay of 34mCl proceeds (46.9 ± 1.0)% to the 34Cl ground state, the latter decay was studied concurrently; 34Cl(0)with Jπ = 0+, T = 1 decays exclusively to its analog 34S(0) and the sum of the intensities of four other allowed branches is less than 1.2 × 10−4 of the intensity of the ground-state branch. The experimental results are compared with recent shell-model calculations performed in a large configuration space.