Elemental analysis device combined with neutron-activation instant and delayed gamma rays

Abstract

The invention discloses an elemental analysis device combined with neutron-activation instant and delayed gamma rays, and belongs to the field of the application of nuclear technology. The elemental analysis device is used for measuring an inelastic scattered instant characteristic gamma energy spectrum of a sample in a combinational manner by using a fast neutron source and a lanthanum bromide detector, measuring a neutron captured instant characteristic gamma energy spectrum in the combinational manner by using a slow neutron source and a high-purity germanium detector and finally measuringa neutron-activation delayed characteristic gamma energy spectrum in the sample by using a sodium iodide detector. Relative to a conventional neutron-activation elemental analysis device, the elemental analysis device provided by the invention not only utilizes instant characteristic gamma rays generated by neutron activation, but also collects delayed characteristic gamma rays; relative to the instant rays, delayed rays have a small quantity, however, are not interfered by a neutron, and further, seldom has the superposition of characteristic peak positions of gamma rays; a specific element is conveniently and accurately analyzed and calculated. A fast neutron and a slow neutron irradiate the sample respectively to increase an irradiation time, and the generation efficiency and the collection efficiency of inelastic scattered gamma rays and neutron captured gamma rays are improved.

Description

technical field [0001] The invention belongs to the application field of nuclear technology, and is a device for analyzing elements by using the principle of neutron activation. technical background [0002] The neutron activation element analysis technique 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 Nuclides release γ-rays with specific energy. According to the energy and intensity of the characteristic γ-rays, the types of elements in the sample and the corresponding element contents can be calculated. [0003] Taking the neutron activated coal element online analysis device as an example, the traditional neutron source is a D-T neutron generator, which generates fast neutrons with an energy of 14 MeV. After the fast neutrons irradiate the coal sample, abnormal Elastic sca...

AI Technical Summary

Problems solved by technology

[0004] In this neutron emission mode, only 1 / 3 of the time of each cycle emits neutrons, and the detector is closed for 1 / 3 of the time, that is, only 1 / 3 of a cycle collects inelastic scattering gamma energy Spectrum and 1 / 3 of the time to collect neutron capture gamma energy spectrum, the effective irradiation time of neutrons and the effective working time of detectors are insufficient, and only about one percent of fast neutrons can be reduced to slow neutrons in energy, The number of γ-rays produced by neutron capture is too small. These reasons lead to the fact that the number of characteristic γ-rays collected by the detector is too small and statistically insufficient. In the actual work process, the energy threshold of inelastic neutron scattering of different element nuclei is different. The inelastic scattering gamma energy spectrum and the neutron capture gamma energy spectrum cannot be strictly separated, especially the neutron capture gamma energy spectrum is often mixed with a large amount of inelastic scattering gamma rays, so the accuracy, stability and lower limit of detection of element content analysis poor

Images