title: Characteristics of the neutron field of the facility at DIN-UPM.
abstract: A new source facility (241Am-Be) has been installed in a bunker-type room of large dimensions. To characterise the neutron fields in the facility, detailed calculations have been made with MCNP-4C, showing the different components of the neutron radiation reaching the reference points (direct, inscattered, backscattered). The contribution from neutrons scattered in the walls to the total ambient dose equivalent remains reasonably low (<10%) in the reference points. Additionally, spectra measurements have been performed with a Bonner spheres spectrometer with a 6LiI(Eu) scintillator (0.4 phi x 0.4 cm2), UTA4 response matrix and BUNKIUT unfolding code. The calculated and experimentally obtained spectra are compared, with small differences found in the epithermal and thermal region, attributable to the concrete composition used in the calculations. The H*(10) rate has been determined from the spectra, and then compared to the reading of an active dosemeter (LB6411), with differences found lower than 8%.
authors.affiliation: Nuclear Engineering Department, Universidad Politécnica de Madrid, C/José Gutiérrez Abascal, 2, E-28006-Madrid, Spain. eduardo.gallego@ctn.din.upm.es
authors.forename: E
authors.initials: E
authors.lastname: Gallego
authors.forename: A
authors.initials: A
authors.lastname: Lorente
authors.forename: H R
authors.initials: HR
authors.lastname: Vega-Carrillo
mesh_terms: D000465:Algorithms; D000576:Americium / Q000032:analysis; D001608:Beryllium / Q000032:analysis; D003198:Computer Simulation; D019544:Equipment Failure Analysis / Q000379:methods / Q000592:standards; D007564:Japan; D008956:Models, Chemical; D009010:Monte Carlo Method; D009502:Neutrons; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods / Q000592:standards*; D011868:Radioisotopes / Q000032:analysis; D011874:Radiometry / Q000379:methods* / Q000592:standards*; D012015:Reference Standards; D012542:Scattering, Radiation; D013030:Spain
chemical_list: D011868:Radioisotopes; D001608:Beryllium; D000576:Americium