0000000000407112
AUTHOR
A. M. Sukhovoj
Low-spin mixed particle–hole structures in 185W
Abstract The level structure of 185W has been studied using the prompt and delayed gamma–gamma coincidences from thermal neutron capture in 184W accompanied with the one-nucleon transfer reactions ( d , p ) and ( d , t ) with polarized beams. From these data and those of previous studies a total of 183 levels has been established for energies below 3 MeV. Many of these states have been grouped into rotational bands built on 28 intrinsic states of quasiparticle and quasiparticle-plus-phonon character. Although the DWBA analysis permitted definite spin–parity assignments for most of states a large number of particle transitions have ‘anomalous’ angular and asymmetry shapes with respect to the…
Parameters of the 125Te compound state cascade gamma-decay
Reliable information on level density and radiative strength functions for the excitation energy region with density of excited states more than 100 levels per 1 MeV and higher can be obtained now only by its model-free extraction from intensities of two-step cascades proceeding between compound states and few low-lying levels. Full model-free determination of these parameters in any method is possible only if one can extract from additional experimental information about general trend in dependence of ratio of strength functions of emitted reaction products of a given type on excitation energy of the nucleus under study. Analysis of the available experimental data for 125Te shows that the …
Nuclear structure of 187W studied with (n,γ) and (d,p) reactions
Abstract The level structure of 187 W has been studied using prompt and delayed gamma–gamma coincidences from thermal neutron capture in 186 W and also measuring the ( d , p ) reaction. From these data and those of previous studies a total of 170 levels (121 connected by γ transitions) have been established for energies below 2.35 MeV. Some of these levels have been grouped into rotational bands built on 14 intrinsic states of quasi-particle and quasi-particle plus phonon character. Of particular interest has been the identification of “quasi bands” with inverse spin sequence based on the newly established isomeric 11 / 2 + state at 410.1 keV. Although the DWBA analysis permitted definite s…
Cascade population of levels and probable phase transition in vicinity of the excitation energy ~0.5Bn of heavy nucleus
From the comparison of absolute intensities of the two-step gamma-cascades and known intensities of their primary and secondary transitions, the cascade and total population of about ~100 levels of 181Hf and 184,185,187W excited in thermal neutron capture was determined. These experimental results and intensities of two-step cascades to the low-lying levels of mentioned nuclei were reproduced in calculation using level densities with clearly expressed step-like structure. Radiative strength functions of the primary transitions following gamma-decay of these compound nuclei to the levels in the region of pointed structure are considerably enhanced. Moreover, population of levels below 3 MeV …