Fast neutron heterogeneous scintillation detector with high discrimination of gamma background
Neutron detectors have been widely used for monitoring security and illicit transportation of nuclear and radioactive materials. Distinguishing feature of such efforts is the necessity to measure such flows of neutron radiation of monitored items which are close to the values of background flow. This paper examines potential improvement of characteristics of multi-layer neutron detector with fiber-optic sensors based on lithium-silicate (6Li) glass by means of polyethylene layers’ replacement with hydrogen-containing layers of scintillating plastic. Combination of two types of neutron-sensitive sensors enables two-phase discrimination due to the amplitude and time criteria of gamma background during the measurements in mixed n-,γ-fields. Presented heterogeneous scintillation detector has much higher gamma-background discrimination factor as compared with existing samples of multilayered neutron detectors while maintaining rather high neutron registration efficiency that is typical for them.
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