Features of the AmBe-based UPM neutron facility

A new automated bench for irradiation, using a AmBe neutron source, has been installed in the neutronics hall at the Universidad Politécnica de Madrid (UPM). In order to determine the neutron field features on the bench a neutron spectrometry, using the Bonner sphere spectrometer, campaign was carried out with the participation of four research teams. Each team used their own spectrometer with different unfolding codes. The UPM-UAZ spectrometer has seven spheres with a 6 LiI(Eu) scintillator, for unfolding this team used the BUNKIUT code. The INFN–LNF spectrometer has 10 spheres with a 6 LiI(Eu) scintillator and the FRUIT code was used for unfolding. The UAB team spectrometer has 11 with a 3 He proportional counter, for unfolding this team used the FRUIT code. The CIEMAT team spectrometer is 12 spheres with a 3 He SP9 counter, for unfolding this team used the UMG code. The paper shows the main results obtained in terms of neutron spectra at fixed distances from the source as well as the total neutron fluence rate and ambient dose equivalent rate H*(10) determined from the spectra. The H*(10) are compared with the readings of a neutron area monitor LB 6411.