High-spin structures of 136Cs

TL;DR

This study investigates the high-spin states of the odd-odd nucleus 136Cs, revealing detailed level schemes up to 4.7 MeV and 16 ħ, supported by experimental gamma-ray data and shell-model calculations.

Contribution

First detailed high-spin level scheme of 136Cs established, with configurations analyzed via analogy to 137Cs and confirmed by shell-model calculations.

Findings

High-spin level scheme constructed up to ~4.7 MeV and 16 ħ.

Configurations involve high-j orbits above Z=50, confirmed by shell-model.

Experimental data supports the proposed nuclear structure interpretations.

Abstract

Odd-odd 136Cs nuclei have been produced in the 18O + 208Pb and 12C + 238U fusion-fission reactions and their gamma rays studied with the Euroball array. The high-spin level scheme has been built up to ~ 4.7 MeV excitation energy and spin I ~ 16 hbar from the triple gamma-ray coincidence data. The configurations of the three structures observed above ~ 2 MeV excitation energy are first discussed by analogy with the proton excitations identified in the semi-magic 137Cs nucleus, which involve the three high-j orbits lying above the Z=50 gap, pi g_{7/2}, pi d_{5/2} and pi h_{11/2}. This is confirmed by the results of shell-model calculations performed in this work.