Lifetime measurement around 132Sn with the ν-Ball array

G Häfner,M Lebois,J N Wilson,J Jolie,R L Canavan,N Jovancevic,R Lozeva,P H Regan,Th Kröll,R B Gerst,A Blazhev,M Rudigier,D Etasse,N Warr,D Thisse

doi:10.1088/1742-6596/1643/1/012135

Abstract

Neutron-rich nuclei were studied after fast neutron-induced fission of 238U and 232Th at the ALTO facility in Orsay, France. The neutrons were produced with the LICORNE directional neutron source using a pulsed 7Li beam provided by the Tandem accelerator. The actinide targets were surrounded by the ν-Ball array to measure the de-excitation of fission fragments. The ν-Ball array is a hybrid spectrometer which consists of HPGe detectors (equipped with BGO shielding) and LaBr3(Ce) scintillation detectors allowing for high-resolution γ-ray spectroscopy and lifetime measurements in the ns/sub-ns range. This contribution presents preliminary results on 134Te and 137I populated in the 238U(n,f) reaction.

Highlights

The study of nuclei around the doubly magic 132Sn provides one of the best testing grounds for nuclear structure studies far away from the valley of stability
Isomers in 134Te The beam pulsing of the Tandem accelerator allows multiple repetitions of the isomeric production, and its identification if it is comparable to the isomeric half-life
Two experiments were performed coupling the array to the LICORNE neutron source to study the de-excitation of neutron-rich fission fragments

Summary

Introduction

The study of nuclei around the doubly magic 132Sn provides one of the best testing grounds for nuclear structure studies far away from the valley of stability. The de-excitation of the resulting fission fragments via γ-rays was measured with the ν-Ball array [2]. 20 LaBr3(Ce) detectors were used for lifetime measurements of excited states in the ns/sub-ns range.

Results

Conclusion