A digital neutron spectrometer

Abstract

The invention relates to a digital neutron spectrometer, comprising a detector unit, a mechanical control unit, a digital acquisition unit and a screening unit; the detector unit is used to detect neutron information of the radiation field to be measured; the mechanical control unit is used to control the detector The rotation and lifting of the unit; the digital acquisition unit is used to convert the analog signal generated by the detector unit into a digital signal; the discrimination unit is used to analyze the pulse shape of the detector unit, and judge whether it is a neutron pulse signal or a γ-ray pulse signal in real time . The neutron spectrometer of the present invention has a wide range of neutron energy measurement; it can effectively determine the effective center position of the detector; it can reduce the influence of detector mutual scattering; The neutron and gamma energy spectrum information are respectively given in real time.

Description

Technical field [0001] The invention belongs to the field of radioactive radiation measurement, and specifically relates to a digital neutron spectrometer. Background technique [0002] Although since the 1950s and 1960s, international developed countries have carried out research on field neutron spectrum measurement technology, due to the complexity of the radiation field in the workplace and the limitation of environmental conditions, the types of mature and practical spectrometers are not many. [0003] At present, the most on-site neutron spectrometer is a multi-sphere spectrometer, also known as a Bonner sphere spectrometer, and a large number of research reports have been conducted at home and abroad. A series of polyethylene balls with different radii and a sphere at the center of the sphere 3 He or BF 3 It is composed of a proportional counter. The radii of the polyethylene ball are 2.5 inches, 3 inches, 3.5 inches, 4 inches, 5 inches, 6 inches, 8 inches, 10 inches and 12...

AI Technical Summary

Problems solved by technology

The main disadvantages of the multi-sphere spectrometer are: 1. The multi-sphere spectrometer uses a few-channel spectrum resolution mechanism, and its neutron energy resolution in the fast neutron energy range above 1 MeV is poor; 2. The measurement process is cumbersome, requiring the measurement personnel to measure It usually takes a day or a few days to measure the neutron energy spectrum of a certain position by placing polyethylene ball detectors of different sizes in sequence; The neutron radiation field is often accompanied by a large number of gamma events, and the multisphere spectrometer cannot distinguish the accumulation gamma events, and cannot provide information on the energy spectrum of the discriminated photons

The shortcomings are also very obvious. The main problems are: 1. The range of neutron energy measured is 50keV ~ 4.5MeV, which cannot cover the energy range of thermal energy ~ 20MeV in ground nuclear facilities; 2. There is a problem of mutual scattering of neutrons between the four detectors. The determination of the single-energy point response function is determined by a single detector, and the mutual scattering problem between the detectors cannot be considered; 3. The effective center position of the detector cannot be determined, and the best measurement condition of the Rospec spectrometer is in a uniform radiation field. Unable to give neutron spectrum information at a certain measurement location

4. The Rospec spectrometer can only deduct gamma events by simply carding the lower threshold, but cannot distinguish the accumulated gamma events, and cannot give information on the energy spectrum of discriminated photons;

Images