The Energy Levels of ¹³⁴Cs

Abstract

<p>The energy levels of ¹³⁴Cs were investigated with single particle transfer reactions, ¹³³Cs (d,p) and ¹³⁵Ba (t,α), and via ϒ-ray spectroscopy studies, ¹³³Cs (d,pϒ) and ¹³⁰Te(⁷Li,³nϒ). The ¹³³Cs(d,p) reaction revealed twentyfive levels up to 936 keV. The ℓ-values and spectroscopic factors were extracted for twenty-three of these levels. Four prominent ℓn = 2 and three prominent ℓn = 0 levels were found. Eleven ℓn = 5 levels were also identified.</p> <p>The ¹³⁵Ba(t,α) reaction showed nineteen levels up to 1319 keV, but ℓ-values and spectroscopic factors were extracted for only eleven of these levels. Four strong ℓp = 4 and seven ℓp = 2 levels were identified.</p> <p>High resolution singles and coincidence ϒ-ray studies in the ¹³³Cs(d,pϒ) and ¹³⁰Te(⁷Li:3n) reactions gave data on the de-excitation of the levels in ¹³⁴Cs. The ¹³³Cs(d,pϒ) study provided detailed information on the levels of ¹³⁴cs • These data provided confirmation of some of the (n,ϒ) work of Alexeev et al. (1975, 1978).</p> <p>A level scheme for ¹³⁴Cs was deduced from the accumulated data. Tentative spin and parity assignments were made for some of the levels. Simple shell model p-n configurations. [πg₇/₂, (νd₃/₂)ˉ¹], [πg₇/₂, (νs₁/₂)ˉ¹], [πg₇/₂, (νb₁₁/₂)ˉ¹] and [πd₅/₂, (νd₃/₂)ˉ¹], were invoked to make the spin assignments. The (d,p) and (t,α) particle data were used to make shell model configuration assignments to some of the energy levels. Poor agreement between the shell model configurations determined in the present study and those assigned by Alexeev et al. (1978) was found.</p>