Magic nucleus 132Sn and its one-neutron-hole neighbor 131Sn

Area of Science:

• Nuclear Physics
• Nuclear Spectroscopy
• Nuclear Structure

Background:

• Doubly magic nucleus 132Sn and its neighbor 131Sn are crucial for understanding nuclear shell structure.
• Previous studies have provided limited information on the excited states and decay properties of these neutron-rich isotopes.

Purpose of the Study:

• To investigate prompt and delayed gamma-ray cascades in 132Sn and 131Sn.
• To assign unknown gamma rays to specific isotopes and nuclear configurations.
• To interpret the observed level spectra using theoretical models of nuclear interactions.

Main Methods:

• Utilized the Gammasphere array with a Californium-248 (248Cm) fission source.
• Analyzed coincidence data between gamma rays and known transitions in Palladium (Pd) fission partners for isotopic assignments.
• Interpreted yrast level spectra using empirical nucleon-nucleon interactions.

Main Results:

• Identified the (νf7/2 h-1 11/2)9+ aligned state in 132Sn.
• Characterized extensive multiplets in 131Sn, including (νf7/2 h-2 11/2), (νf7/2 d-1 3/2 h-1 11/2), and (νh-1 11/2 × 3−) configurations.
• Elucidated the beta- decay of a previously reported 131In high-spin isomer to levels in 131Sn.

Conclusions:

• The study provides detailed insights into the nuclear structure of neutron-rich tin isotopes.
• The identified configurations and interactions contribute to a better understanding of nuclear shell effects near doubly magic nuclei.
• The findings enhance the nuclear data for 132Sn and 131Sn, aiding future theoretical and experimental nuclear physics research.