We developed optical fiber-based neutron detectors that use small pieces of6Li-based scintillators, namely, Eu:LiCaAlF6 crystals and LiF/Eu:CaF2 eutectics. Considering that these elements have high light yields (more than 10,000 photons/neutron), they can produce pulse height spectra with clear peaks even when using optical fiber light guides. To adjust the neutron sensitivity, we controlled the amount of6Li in the scintillator. We fabricated three different detectors using Eu:LiCaAlF6 and LiF/Eu:CaF2 with various amounts of6Li and then evaluated the neutron sensitivity of each detector. This approach confirmed that there was a linear relationship between the neutron sensitivity and amount of6Li, thus implying that the6Li mass measured by a high-precision balance could be a good metric of neutron sensitivity. We also checked the linearity of the output of the detector at relatively high neutron fluxes by using an accelerator-based neutron source. Although the detectors showed saturation behavior at high count rate, we were able to cover a relatively wide dynamic range by combining multiple detectors using different amounts of6Li. After correcting for the pulse height distortion and count loss due to pile-up events, we were able to confirm the linearity of the detectors up to a count rates of 100 kcps.
|Journal||Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|
|Publication status||Published - Feb 21 2020|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics