Nuclear Structure and Dynamics - NSD 2019

Gamma and fast-timing spectroscopy of 132Sn from the beta-decay of In isotopes

14 May 2019, 15:20

20m

SALA VIVALDI (Centro Culturale Don Orione Artigianelli)

Oral Session XI (Parallel Session)

Speaker

Mr Jaime Benito (Grupo de Física Nuclear, Universidad Complutense de Madrid)

Description

Nuclei with a large N/Z ratio in this region are of great interest to test nuclear models and provide information about single particle states. During the last two decades there has been a substantial effort directed to gathering information about the region around 132Sn[1-3], the most exotic doubly-magic nucleus presently at reach. 132Sn is itself a very interesting case [4]. The simplest excited levels correspond with particle-hole states where a particle is excited across the energy gap of the closed shell. The identification of the p-h multiplets, provides information on the nuclear two-body elements. This isotope has been studied in detail through the β-decay of 132In [5]. Nevertheless, a lot of the expected p-h multiplet states remained unidentified.
We have used fast-timing and γ spectroscopy to investigate 132Sn. The experiment was carried out at ISOLDE, where the excited states of 132Sn were populated in the β-decay of In isomers, produced in a UCx target unit equipped with a neutron converter. The In isomers were ionized using the ISOLDE RILIS, which for the first time allowed isomer-selective ionization of indium. The measurements took place at the new ISOLDE Decay Station, equipped with four clover-type Ge detectors, along with a fast-timing setup consisting of two LaBr3(Ce) detectors and a fast β detector.
In this work we report on the excited structure of 132Sn, populated in the β-decay of 132In, and also, owing to the RILIS isomer selectivity, separately from the β-n decay of the 133In 1/2- isomer and 9/2+ ground state. We present a preliminary new level-scheme, which have been enlarged with 13 new levels and more than 40 new γ-transitions. These results are completed with new lifetimes values of excited states.
[1]K.L.Jones et al.,Nature 465,454(2010).
[2]J.M.Allmond et al.,Phys.Rev.Lett.112,172701(2014).
[3]A.Korgul et al,PhysRevLett 113,132502(2014)
[4]D.Rosiak et al.,Phys.Rev.Lett.121,252501(2018)
[5]B.Fogelberg et al Phys.Rev.Lett.73,2413(1996)