Digital neutron spectrometer

Abstract

The invention relates to a digital neutron spectrometer, which comprises a detector unit, a mechanical control unit, a digital acquisition unit and a discrimination unit, wherein the detector unit is used for detecting neutron information of a radiation field to be detected; the mechanical control unit is used for controlling rotation and lifting of the detector unit; the digital acquisition unit is used for converting analog signals generated by the detector unit into digital signals; and the discrimination unit is used for analyzing the shape of pulses of the detector unit, and judging whether the pulses belong to neutron pulse signals or Gamma-ray pulse signals in real time. The neutron spectrometer provided by the invention is wide in neutron energy measurement range, can effectively determine an effective central position of detector measurement, reduce mutual scattering influences of detectors, has a good neutron and photon real-time discrimination ability, and respectively gives neutron and Gamma energy spectrum information in a neutron-Gamma mixed filed in real time.

Description

technical field [0001] The invention belongs to the field of radioactive radiation measurement, in particular to a digital neutron spectrometer. Background technique [0002] Although since the 1950s and 1960s, international developed countries have carried out research on on-site neutron spectrum measurement technology, but due to the complexity of the radiation field in the workplace and the limitations of environmental conditions, mature and practical spectrometer types are not available. many. [0003] At present, the most on-site neutron spectrometers are multi-sphere spectrometers, also known as Bonner sphere spectrometers, and a large number of research reports have been carried out at home and abroad. Consisting of a series of polyethylene spheres of different radii and a spherical centered 3 He or BF 3 Composed of proportional counters, the radii of polyethylene balls are 2.5 inches, 3 inches, 3.5 inches, 4 inches, 5 inches, 6 inches, 8 inches, 10 inches and 12 i...

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 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;

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