| 摘要 |
A device for detecting neutrons and gamma rays comprises at least one detector and an acquisition and data-analysis system, connected to the detector; the detector comprises an active part that is formed by a plurality of: scintillator layers, made of a scintillator material, in particular a plastic scintillator; and absorber layers, containing at least one neutron-absorbing material, in particular cadmium or gadolinium; the acquisition and data-analysis system is configured so as to: analyse the signals coming from the detector and calculate the total energy released within the detector following upon an interaction with gamma rays or neutrons; and discriminate between gamma rays and neutrons impinging upon the detector according to whether the energy detected is higher or lower than a pre-set threshold. |
| 主权项 |
1. A device (1) for detecting neutrons and gamma rays, in particular coming from radionuclides carried by persons and/or vehicles moving along a pre-set path, comprising at least one detector (2) and an acquisition and data-analysis system (3), connected to the detector (2); wherein the detector (2) has just one active part (7) that extends along a longitudinal axis (A) and only includes one or more active materials sensitive to gamma rays, being formed by: a plurality of scintillator layers (8) sensitive to gamma rays, made of a scintillator material sensitive to gamma rays, in particular a plastic scintillator, for example polyvinyltoluene; and, set in between, absorber layers (9), containing at least one neutron-absorbing material, in particular cadmium or gadolinium; the scintillator layers (8) and the absorber layers (9) having substantially the shape of a thin sheet or plate and being coupled to one another on respective substantially plane faces; and wherein both the gamma rays and the neutrons are detected via the same scintillator layers (8) sensitive to the gamma rays and via the gamma emission generated by interaction of the neutrons with the absorber material of the absorber layers (9); the device (1) being characterized in that the detector (2) is organized in sections, the scintillator layers (8) and the absorber layers (9) being arranged in two or more active sections (15A, 15B) formed by respective groups of scintillator layers (8) alternating with absorber layers (9); each active section (15A, 15B) having two or more scintillator layers (8), which alternate with absorber layers (9) and are optically connected to a single pair of photomultipliers (13A, 13B), set at respective axially opposite longitudinal ends (11A, 11B) of the active section (15A, 15B) for collecting energy released by the interaction of the gamma rays with the scintillator material, each pair of photomultipliers (13A, 13B) being optically connected to a number of scintillator layers (8) alternating with absorber layers (9), and the active sections (15A, 15B) being read independently by the respective photomultipliers (13A, 13B). |
