Device for detecting French chalk content in flour

Abstract

The invention discloses a device for detecting French chalk content in flour, and belongs to the field of nuclear technology application. The device utilizes a neutron activation principle to irradiate the flour with neutrons with energy of 14 MeV, short-lived radionuclide 28Al and 24Na are generated by the reaction between the neutrons and 28Si and 24Mg which are the main elements in French chalk(Mg3[Si4O10](OH)2), and by measuring delayed characteristic gamma rays released by the 28Al and 24Na, whether or not the flour contains French chalk is determined and the specific French chalk content is calculated. The device can penetrate the surface of the tested flour to measure the French chalk content of the inside, compared with chemical detection, the speed is fast, no sampling is needed,and the device can be directly installed on a transport belt, is suitable for real-time online detection, and has high detection precision, low detection limit, long-term measurement stability and strong anti-interference ability.

Description

technical field [0001] The invention belongs to the application field of nuclear technology, and is a device for detecting the content of talcum powder in flour by using the principle of neutron activation. technical background [0002] Neutron activation elemental analysis technology uses neutrons to irradiate the sample to be tested, and the neutrons will interact with the atomic nuclei in the sample, such as inelastic scattering, elastic scattering, neutron capture, etc., and the atomic nuclei are activated into radioactive nuclei. Elements release gamma rays with specific energy. According to the energy and intensity of the characteristic gamma rays, the type of element in the sample and the corresponding element content can be calculated. [0003] The traditional on-line detection technology of neutron-activated elements is based on collecting the prompt characteristic gamma rays generated after neutron activation of the sample to be tested for element content analysis....

AI Technical Summary

Problems solved by technology

[0003] The traditional on-line detection technology of neutron-activated elements is based on collecting the prompt characteristic gamma rays generated after neutron activation of the sample to be tested for element content analysis. The prompt characteristic gamma rays are mainly caused by the inelastic scattering of neutrons and atomic nuclei (n ,n'γ) and neutron capture (n,γ), the production of prompt characteristic γ-rays is concentrated within 1 microsecond after the reaction of neutrons and nuclei, which is characterized by high intensity, large number, and high energy (mostly distributed 2MeV~10MeV), but due to the reaction of neutrons with the surrounding environment, especially radiation protection materials, a large number of interfering rays are produced, and the characteristic gamma rays of different elements have many similar energies, while the energy resolution of the gamma ray detector is insufficient, and a large number of gamma ray characteristic peaks Overlapping together is very unfavorable for spectral analysis. Specifically, due to the inelastic scattering of neutrons and the main elements of flour, C, H, O, N, etc., a large number of strong γ-rays are generated, among which the characteristic rays of C are 3.68MeV and 4.95MeV and The energy of characteristic rays 3.54MeV and 4.93MeV of Si, the main element of talcum powder, is close to that of the detector, and the other main element of talc powder, Mg, is annihilated in the interference rays because the intensity of the instantaneous characteristic γ-ray is too weak.

In addition, after a large number of neutrons irradiate the detector, the radiation damage performance of the detector will be reduced.

[0004] In the flour production process, some manufacturers have backward production technology and will add 2%-3% talcum powder to the flour as a dispersant to prevent the flour from sticking. Some unscrupulous manufacturers in the market mix as much as 20% talcum powder for profit, long-term large-dose use will cause renal silicate stones, and patients with renal insufficiency may experience dizziness, fainting, arrhythmia or mental symptoms, and abnormal fatigue and weakness

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