Speaker
Description
Few data exist regarding the yields and the six group time spectra of delayed neutrons from the photofission reaction on actinides. In 1966, Nikotin et al. published data for the photofission of 232Th, 235U, 238U and 239Pu induced by Bremsstrahlung photons with an endpoint energy at 15 MeV. In 1970, Kull et al. presented data for the photofission of 235U and 238U at both 8 and 10 MeV. In 2009, Macary et al. provided data for the photofission of 235U and 237Np for a couple of endpoint energies below 20 MeV. In this study, new experimental data are reported for the photofission of 238U induced by Bremsstrahlung photons below 9 MeV. This work was conducted using a Linatron M9 linear electron accelerator manufactured by Varex Imaging Corp. and housed at the SAPHIR platform, which is located at CEA Paris-Saclay, France. Either 6 or 9 MeV electrons were converted to Bremsstrahlung photons thanks to its tungsten target. Samples of 238U were positioned inside a high-density polyethylene neutron detection array designed and optimized using the MCNP6 Monte-Carlo simulation code and including ten one meter-long 3He counters. The novel results presented in this study for the photofission of 238U induced by Bremsstrahlung photons below 9 MeV bring valuable information to the scarce – and sometimes contradictory – data available in the literature. Furthermore, these new experimental data represent useful inputs for the development of nuclear measurement systems based on the photofission reaction. Such systems meet a significant interest in the field of nuclear waste package characterization and for security-related applications.