Calibration of a large-size wide-range neutron spectrometer

Over the last year, Politecnico di Milano has developed the W-PIE, a cosmic neutron spectrometer employed for environmental measurements. The W-PIE is based on the Artkis M800 thermal neutron detector and works as a 4-channel spectrometer for detecting neutrons in the energy range 0.01eV - 1GeV. In this paper, the calibration of the instrument in monoenergetic neutron fields at the PIAF facility of PTB is discussed. These measurements were intended to calibrate the detector and validate the response functions. Despite obtaining satisfactory results in terms of fluence and dose calculations, the irradiation in the monoenergetic fields suggested that the detector sensitivity to fast neutrons was greater than expected by the calculated response functions. This discrepancy was investigated and a reasonable explanation for it was proposed.