Evidence of nonstatistical neutron emission following beta decay near doubly magic Sn-132

Heideman, J, Grzywacz, R, Xu, ZY, Madurga, M, Escher, JE, Kawano, T, Algora, A, Andreyev, AN, Benito, J, Berry, T
et al (show 39 more authors) (2023) Evidence of nonstatistical neutron emission following beta decay near doubly magic Sn-132. PHYSICAL REVIEW C, 108 (2). 024311-.

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Models of the β-delayed neutron emission (βn) assume that neutrons are emitted statistically via an intermediate compound nucleus post β decay. Evidence to the contrary was found in an In134β-decay experiment carried out at ISOLDE CERN. Neutron emission probabilities from the unbound states in Sn134 to known low-lying, single-particle states in Sn133 were measured. The neutron energies were determined using the time-of-flight technique, and the subsequent decay of excited states in Sn133 was studied using γ-ray detectors. Individual βn probabilities were determined by correlating the relative intensities and energies of neutrons and γ rays. The experimental data disagree with the predictions of representative statistical models which are based upon the compound nucleus postulate. Our results suggest that violation of the compound nucleus assumption may occur in β-delayed neutron emission. This impacts the neutron-emission probabilities and other properties of nuclei participating in the r-process. A model of neutron emission, which links the observed neutron emission probabilities to nuclear shell effects, is proposed.

Item Type: Article
Uncontrolled Keywords: 5106 Nuclear and Plasma Physics, 5110 Synchrotrons and Accelerators, 51 Physical Sciences
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 12 Sep 2023 07:42
Last Modified: 21 Jun 2024 00:00
DOI: 10.1103/PhysRevC.108.024311
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3172671