Levels in 200Hg populated in the β- decay of the 19 h isomer of 200Au and in the reaction 198Pt(α, 2nγ)200Hg have been investigated. The β-decay populates an 11- level in 200Hg at 2642 keV, which de-excites through levels at the following energies (spin-parities): 2144(9-), 1963(7-), 1852(5-), 1707(6 +), 947(4+) and 368(2+) keV. The relative γ-ray intensities measured in the in-beam experiment were invaluable in the construction of an unambiguous 200Hg level spectrum. The 9- → 7- and 7 - → 5- E2 transitions are considerably enhanced suggesting that the negative-parity levels constitute a collective "band". It is proposed that the β- decay involves a one-particle transition between the (h 11 2π, i 13 2ν)12- isomer of 200Au and a (h 9 2ν, i 13 2ν) two-neutron admixture in the 200Hg 11- state. Indications of the systematic occurrence of similar sequences of negative-parity levels in other A = 190-200 transitional nuclei are discussed.
|Number of pages||12|
|Journal||Nuclear Physics, Section A|
|State||Published - Dec 4 1972|
- Nuclear reactions
ASJC Scopus subject areas
- Nuclear and High Energy Physics