New measurement of the Pu(n, ) cross section at n_TOF-EAR1 for MOX fuels; Preliminary results in the RRR

Lerendegui-Marco, J.*; Guerrero, C.*; Harada, Hideo   ; Kimura, Atsushi   ; n_TOF Collaboration*; 115 of others*

The use of MOX fuels in thermal and fast reactors requires accurate capture and fission cross sections. For the particular case of Pu, the previous neutron capture cross section measurements were made in the 70's, providing an uncertainty of about 35% in the keV region. NEA WPEC-26 reports that the capture cross section of Pu should be measured with an accuracy of at least 7-12% in the neutron energy range between 500 eV and 500 keV. This work presents a brief description of the measurement performed at n_TOF-EAR1, the data reduction process and the first ToF capture measurement on this isotope in the last 40 years, providing preliminary individual resonance parameters, as well as a preliminary set of average resonance parameters.