The cross-section for the reaction 133CS(n,γ)134Cs in the NRX reactor

The effective cross-sections, $\text{}\text{̂}$gs and cadmium ratios, R_Cd for the reaction ¹³³Cs(n,γ)¹³⁴Cs (2·17 yr) have been measured in three different positions of the NRX reactor and the results interpreted by means of the Westcott convention to give values for the 2200 m/sec cross-section, σ₀, and the resonance integral, Σ. Measurements were made relative to the cross-sections for the reaction ⁵⁹Co(n,γ)⁶⁰Co (5·28 yr). $\text{}\text{̂}$gs varies from 34 barns in a graphite shielded position outside the reactor calandria to 41 barns in a vacant fuel rod position. The values of σ₀ and Σ derived are 33·4 ± 2·6 barns and 370 ± 50 barns respectively, where Σ is evaluated from 0·5 eV upwards and includes the $\text{1}\text{v}$ part. The errors are standard deviations and include the errors in the measurements and the errors in the input data; they do not include errors which could arise in the interpretation of the data.