Gamma-ray spectroscopy in the decay of (83)Se to levels of (83)Br.
High-resolution γ ray spectroscopy experiments have been done to study the emissions from the radioactive decay of 22-min (83g)Se produced from neutron capture using samples of enriched (82)Se. Energy and intensity values have been obtained to roughly an order of magnitude greater precision than in previous studies. Based on energy sums, 2 new levels are proposed in the daughter (83)Br and one previously proposed level is shown to be doubtful. Some 25 new transitions appear to decay with the (83)Se halflife, about half of which can be accommodated among the previous or newly proposed levels. Several previous γ ray placements are shown to be inconsistent with the new determinations of the (83)Br energy levels, but cannot be accommodated anywhere else among the known levels. As a result of the missing γ ray placements, some of the β branchings in the decay to levels of (83)Br appear to be negative. Gamma rays from the 2.4-h decay of the daughter (83)Br to levels of (83)Kr have also been observed, along with decays of (81g)(,m)Se present as a small impurity in the enriched samples and also as a strong component in irradiated samples of natural Se.
Nuclear Data Sheets for A = 169
Abstract Experimental data pertaining to all nuclei with mass number A = 169 (Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt) have been evaluated. Level schemes from both radioactive decay and reaction studies are presented, along with associated tables of experimental data and adopted properties for levels and γ rays. These include data from several recent high-precision measurements of intensities for γ rays emitted in 169Yb e decay; these are of special interest because of their use as calibration standards. Excited-state information is newly available for Re, Os, Ir and Pt, and heavy-ion reaction studies have significantly expanded our knowledge of excited states in Lu through Ta. More extensive work on e decay from W is needed and new experimental work will be required to resolve a discrepancy between the Jπ values deduced for a 180-keV level in 169Ta based on extensive band structure from (HI,xnγ) work (Jπ = 1/2–) and TDPAD measurements (J = 5/2). The present evaluation for A = 169, which considers data received by 15 June 2008, supersedes the 1991 evaluation (with a literature cutoff date of March 1990) by V. Shirley, published in Nuclear Data Sheets 64, 505 (1991).
Correlations for mass transfer between fluidized spheres and a liquid
Abstract Data on mass transfer between the solid particles and the liquid in a fluidized bed have been analyzed. After a convenient selection, various correlations have been derived. They show that for a given fluidized system, the Sherwood number is independent on the Reynolds number.