Relative U235(n,γ) and (

Abstract

Relative 235 U(n,γ) and (n,f) cross sections from 235 U(d,pγ) and (d,pf) The internal surrogate ratio method allows for the determination of an unknown cross section, such as (n,γ), relative to a better-known cross section, such as (n,f), by measuring the relative exitchannel probabilities of a surrogate reaction that proceeds through the same compound nucleus. The validity of the internal surrogate ratio method is tested by comparing the relative gamma and fission exit-channel probabilities of a 236 U * compound nucleus, formed in the 235 U(d,p) reaction, to the known 235 U(n,γ) and (n,f) cross sections. A model-independent method for measuring the gamma-channel yield is presented and used.

Spin differences in the Zr90 compound nucleus induced by (p,p′) , Ota1, Burke2, Casperson3 et al. 2015Phys. Rev. CSelf Cite233280View full textAdd to dashboardCite

“…This, in turn, leads to a competition between γ decay and neutron emission that is quite sensitive to the J π distributions of the decaying compound nuclei and can be expected to be visible in the measured discrete γ-ray emission probabilities [7,14,17]. The effect is smaller in well-deformed nuclei with high level densities, such as rare-earth and actinide nuclei that have been studied in [15,23]. Additionally, investigating the 90 Zr nucleus also has the advantage that the nuclear structure of 90 Zr and neighboring nuclei have been extensively studied.…”

Indirect determination of neutron capture cross sections on spherical and near-spherical nuclei using the surrogate method

“…Ref. [9]). For the statistical tagging technique, a model-dependent approach may be necessary to estimate angular momentum population distributions and constrain the γ-ray energy range to isolate primary γ-transitions.…”

“…This effort was recently expanded to include the determination of neutron capture cross sections. Two approaches have been applied to tag the γ-decay channel in the indirect determination of neutron capture cross sections using the surrogate method: discrete tagging [8][9][10][11] and statistical tagging [12,13].…”

Neutron-capture cross sections from indirect measurements

“…We find that the internal ratio approach shows closer agreement than the external surrogate ratio approach. Experimentally, the internal ratio method has been explored by Bernstein et al [23] and by Allmond et al [24].…”