Position sensitive ZnO:Zn neutron detector – A high count rate alternative to ZnS:Ag scintillation detectors

Abstract

ZnO:Zn is a low afterglow scintillator that is investigated here as a possible higher count rate alternative to ZnS:Ag for scintillation neutron detectors at scattering facilities. In the present work the first position sensitive neutron detector using ZnO:Zn has been produced and its detector performance is evaluated in comparison to a typical ZnS:Ag detector. The detection efficiency of the ZnO:Zn detector at 1 Å was measured to be 74% that of the ZnS:Ag detector, due to lower light output and collection in the ZnO:Zn detector. The trigger efficiency of the ZnO:Zn detector was 61% with gamma sensitivities on the order of 10−5; in comparison, the ZnS:Ag detector was able to achieve trigger efficiencies of 94% at gamma sensitivities ∼10−6. Areas of development to improve these limitations will be discussed. Most importantly, the rate capability of the ZnO:Zn detector was demonstrated to be approximately two times higher than the current standard ZnS:Ag scintillation detectors. With optimisation of signal processing parameters a factor of six times improvement in rate capability may be possible, indicating potential for the use of ZnO:Zn detectors in higher count rate applications.