Due to the need for accurate neutron spectrum measurements in environments characterized by very high neutron and photon fluence rates, such as medical LINACs and the target area of particle accelerators, many research groups have adopted gold activation detectors inside Bonner sphere based instruments. Consequently, several response matrices have been derived. Nevertheless, the validation of such functions with reference neutron fields is still a difficult task, due to the limited availability of high fluence rate calibration facilities. An Italian collaboration, coordinated by the Radiation Protection Group of the Frascati National Laboratories, calculated the response matrix of a commercial BSS equipped with gold foils (0.1 mm height xx 10 mm diameter) and performed a validation experiment with a 252Cf source available at the ENEA-Bologna calibration laboratory. As a result, a spectrometric system with known accuracy is now available for workplace measurements. This work gives the details of the calculations, performed with MCNP, and shows the results of the validation experiment.
Determination and Validation of a Response Matrix for a Passive Bonner Sphere Spectrometer Based on Gold Foils
2008-02-01
Abstract
Due to the need for accurate neutron spectrum measurements in environments characterized by very high neutron and photon fluence rates, such as medical LINACs and the target area of particle accelerators, many research groups have adopted gold activation detectors inside Bonner sphere based instruments. Consequently, several response matrices have been derived. Nevertheless, the validation of such functions with reference neutron fields is still a difficult task, due to the limited availability of high fluence rate calibration facilities. An Italian collaboration, coordinated by the Radiation Protection Group of the Frascati National Laboratories, calculated the response matrix of a commercial BSS equipped with gold foils (0.1 mm height xx 10 mm diameter) and performed a validation experiment with a 252Cf source available at the ENEA-Bologna calibration laboratory. As a result, a spectrometric system with known accuracy is now available for workplace measurements. This work gives the details of the calculations, performed with MCNP, and shows the results of the validation experiment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
