The ²³⁶U neutron capture cross-section measured at the n_TOF CERN facility

Abstract

Abstract. The 236 U isotope plays an important role in nuclear systems, both for future and currently operating ones. The actual knowledge of the capture reaction of this isotope is satisfactory in the thermal region, but it is considered insufficient for Fast Reactor and ADS applications. For this reason the 236 U(n, γ ) reaction crosssection has been measured for the first time in the whole energy region from thermal energy up to 1 MeV at the n TOF facility with two different detection systems: an array of C 6 D 6 detectors, employing the total energy deposited method, and a 4π total absorption calorimeter (TAC), made of 40 BaF 2 crystals. The two n TOF data sets agree with each other within the statistical uncertainty in the Resolved Resonance Region up to 800 eV, while sizable differences (up to 20%) are found relative to the current evaluated data libraries.Moreover two new resonances have been found in the n TOF data. In the Unresolved Resonance Region up to 200 keV, the n TOF results show a reasonable agreement with previous measurements and evaluated data.