Several (n,) techniques at thermal and resonant neutron energies have been used to investigate the level scheme of Hg202. Low and high energy (n,) spectra have been measured at the Brookhaven National Laboratory high flux beam reactor using Ge(Li) detectors. Two parameter coincidence spectra and γ-γ angular correlation data were taken. Primary transitions from resonance capture in Hg201 were studied with the fast chopper facility at BNL. The combination of these data led to the construction of a detailed level scheme up to about 2 MeV. Twenty-two excited states were found, most of which could be given spins or spin limits. As in Hg200 a systematic behavior of the level population as a function of energy and spin was observed and could be used for spin assignments. Most of the levels, and in particular their γ deexcitations, were not accurately known previously. Of special interest is the observation that the lowest excited 0+ state is at 1564 keV. Another 0+ state was discovered at 1643 keV. These findings shed new light on the "extra" 0+ state in Hg200 at 1029 keV. The systematics of level energies and branching ratios in the Hg isotopes is treated and is found to be suggestive of significant nuclear structure differences as a function of neutron number. In particular, a comparison with model calculations for core-coupled states revealed extensive disagreements for Hg202, in contrast to the rather satisfactory comparison found in Hg200. NUCLEAR REACTIONS Hg201(n,), E=thermal, 43, 70.9, and 210 eV. Measured Eγ, Iγ, γ-γ coin(-) in Hg202. Hg202 deduced levels, transitions, J, π.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics