0000000000377031
AUTHOR
S.a. Hjorth
On the decay of compound nuclei following alpha-particle and12C induced reactions
Multiple coincidence rates have been measured using a detector system consisting of a Ge(Li) spectrometer and eight NaI(Tl) or eight liquid scintillators. Reactions induced byα-particles with energies of 51–55 MeV and 118 MeV12C ions are studied. The data are analysed to give the first and second central moments of the distribution of the number ofγ-rays feeding individual levels in the final nuclei. When these numbers are compared to spin distributions calculated with the statistical model code GROGI the relative importance of dipole and quadrupole deexcitation modes can be ascertained. In particular, in the122Te(α, 4n)122Xe reaction theγ-decay prior to the entry into the ground band is we…
Search for High-Spin Isomers in 150Dy
A search for yrast traps in 150Dy has been made by studying the γ-ray decay following the 144Nd (12C, 6n) 150Dy and 146Nd (12C, 8n) reactions. Although an average value of about 30 units of angular momentum is imparted to the final nucleus using these reactions, no evidence is found for the existence of isomers with half-lives longer than 10 ns.
High spin shell model excitations in149Gd
The high spin level structure of the three-neutron nucleus149Gd has been investigated by in-beamγ-ray and electron spectroscopy with (α, xn) reactions. The observed levels are characterized as members of the shell model multipletsνf 7 2/3 ,νh 9/2 f 7 2/2 ,νf 7 2/3 ×3−,νh 9/2 f 7 2/2 ×3−, and tentativelyνf 7 2/3 ×(3−)2. The energies of theν f 7 2/3 states agree only moderately with those calculated using empirical two-nucleon interactions taken from148Gd, which indicates the importance of long range contributions already atN=85.