Characterization and use of Stilbene scintillator for neutron metrology and spectrometry from 100 keV to 22 MeV

Abstract

Stilbene scintillators have now the capability to extend the neutron energy measurement from 100 keV to 1 MeV. To be used as spectrometers, scintillators have to be characterized in entire energy range covered. For the photon characterization, usual calibration source determined the calibration and the resolution function. To do the photon matrix, MCNP PTRAC simulations were done between 59 keV up to 7 MeV. Using MCNP PTRAC allows the calculation of the photon response matrix from the tracking detail of the electron energy deposition in the crystal, including the effect of the Aluminum protection around. Resolution and sensibility obtained from gamma sources are applied later to the calculated photon matrix. For neutron characterization, Time-Of-Flight measurements on white neutron spectra were realized. However, the fluence reference on these spectra begins at 1 MeV. So, the shape of the response function was measured using stilbene scintillators on 100 keV1 MeV decade. After, the monoenergetic neutron reference of AMANDE facility was used to give neutron fluence normalization below 1 MeV. This method could characterize these scintillators for neutron energy from 100 keV up to 22 MeV.

Keywords

• scintillator characterization
• digital acquisition
• neutron
• time-of-flight
• stilben