The BNCT group in Pavia developed a boron concentration measurement technique based on α spectroscopy and neutron autoradiograpy, that allow obtaining both the concentration and the spatial distribution of 10B in biological samples. However, since α spectroscopy requires that the sample is irradiated under vacuum, it cannot be exploited for liquid samples such as urine and blood. For this reason, a prompt gamma neutron activation analysis (PGNAA) facility will be installed at the Triga Mark II reactor at Pavia University. In order to design a PGNAA facility, the Monte Carlo code MCNP4c2 was used. An input file describing the geometry and the neutron source of the Triga reactor was used, and modified to design the components necessary for the beam filtering, collimation and shielding. Given the geometry of the facility and the irradiation position quite peripheral with respect to the reactor core, different variance reduction techniques were implemented to optimize the neutron and gamma transport. Following, the best set-up among the different configurations tested is described.
Design of a facility for boron measurement based on neutron activation analysis
BALLARINI, FRANCESCA;BORTOLUSSI, SILVA;PROTTI, NICOLETTA;ALTIERI, SAVERIO
2011-01-01
Abstract
The BNCT group in Pavia developed a boron concentration measurement technique based on α spectroscopy and neutron autoradiograpy, that allow obtaining both the concentration and the spatial distribution of 10B in biological samples. However, since α spectroscopy requires that the sample is irradiated under vacuum, it cannot be exploited for liquid samples such as urine and blood. For this reason, a prompt gamma neutron activation analysis (PGNAA) facility will be installed at the Triga Mark II reactor at Pavia University. In order to design a PGNAA facility, the Monte Carlo code MCNP4c2 was used. An input file describing the geometry and the neutron source of the Triga reactor was used, and modified to design the components necessary for the beam filtering, collimation and shielding. Given the geometry of the facility and the irradiation position quite peripheral with respect to the reactor core, different variance reduction techniques were implemented to optimize the neutron and gamma transport. Following, the best set-up among the different configurations tested is described.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
