| Description |
In this thesis, the fast neutron spectrometry and pulse shape discrimination feature were studied using a Boron-loaded liquid scintillator, which utilizes the capture-gated counting method. This method is based on the measurement of two signals generated by the sequential interactions from the same neutron in the detector. The neutron-capture pulse is gated by the recoil-proton pulse so that only neutrons whose energy has been finally absorbed are recorded, because the amplitude of the recoil-proton pulse does not reflect the energy of the incident neutron, unless the neutron is successfully thermalized and captured. When a neutron fully deposits its energy in the active region of the detector, the recoil-proton pulse amplitude is strongly correlated to the incident neutron energy. This serves as the basis of neutron spectroscopy. In current practice of the capture-gated technique, it is always assumed that capture only happens after the incoming neutron loses all of its kinetic energy. In this thesis, we show that this assumption may cause degradation of energy resolution that can be corrected based on capture time. The concept of our approach is demonstrated by simulation using the Geant4 toolkit. In addition, the pulse shape discrimination feature of this detector will be discussed using Geant4 simulation as well. |
