Electromagnetic transition strengths in 24Na

Abstract

Mean lifetimes, excitation energies and branching ratios of 24Na states, populated in the 23Na(d, p)24Na reaction have been measured. Gamma-ray spectra were measured at three angles in coincidence with proton groups at θp = 169°. Mean lifetimes obtained from DSA are (excitation energy in keV, lifetime in fs): 563, > 1000; 1341, 95 ± 30; 1344, 38 ± 11; 1346, > 1500; 1512, 38 ± 11; 1846, 260 ± 50; 1885, 36 ± 9; 2513, 15 ± 7; 2563, < 25; 2904, 50 ± 15; 2978, < 25; 3216, 22 ± 8; 3372, 19 ± 5. For higher levels up to 4207 keV upper limits of 30 fs were set. In combination with earlier work the following unique spin(-parity) assignments could be made: Jπ(1846) = 2+, J(2513) = 3, Jπ(3745) = 3−. A new level at Ex = 3681.7 ± 0.6 keV is reported.