X-ray energy spectrum measurement method based on flat crystal diffraction imaging

Abstract

The invention relates to an X-ray energy spectrum measurement method based on flat crystal diffraction imaging. By using the method, disadvantages that energy spectrum resolution is poor and measurement efficiency is low in an existing method are overcome. The method is suitable for multi-energy X-ray continuous energy spectrum measurement below 100keV. The method comprises the following steps of 1, estimating an energy spectrum scope of an X ray to be measured and determining a diffraction crystal parameter and a measurement system parameter; 2, carrying out imaging on all the diffraction angles in a diffraction angle scope and recording a diffraction image and a transmission image; 3, for a crystal determined in the step1, using a direct current X-ray source and an energy distinguishing detector to measure a rocking curve of each energy X ray to a diffraction crystal in the energy spectrum scope to be measured and calculating an integral diffraction coefficient; 4, according to the transmission image in the step2, calculating diffraction energy corresponding to each pixel of the diffraction image in the step2 so as to acquire an X-ray diffraction energy spectrum; and combining the integral diffraction coefficient of each energy to be measured in the step3 to calculate an incident X ray energy spectrum.

Description

technical field [0001] The invention belongs to the field of X-ray energy spectrum measurement, and relates to an X-ray energy spectrum measurement method based on flat crystal diffraction imaging. Background technique [0002] In the field of X-ray energy spectrum measurement, especially in pulsed X-ray measurement, energy spectrum is a very important parameter. At present, there are many energy spectrum measurement methods, including crystal spectroscopy, filter absorption method, single photon CCD measurement, differential filter method, etc., and the corresponding energy spectrum inversion algorithm has been developed. [0003] The above existing methods all have certain advantages, but also have certain problems. The filter absorption method has a wide range of energy spectrum measurement, and can measure energy spectrum and angular distribution at the same time. However, due to indirect measurement, the energy spectrum resolution is poor, and large errors may occur in...

AI Technical Summary

Problems solved by technology

The filter absorption method has a wide range of energy spectrum measurement, and can measure energy spectrum and angular distribution at the same time. However, due to indirect measurement, the energy spectrum resolution is poor, and large errors may occur in the inversion process; single-photon CCD can realize online measurement and obtain real-time The measurement results are easy to apply, but the resolution of the energy spectrum is low, and the upper limit of the energy spectrum measurement is low (limited by the response efficiency of the CCD pixel to X-rays, generally not higher than 30keV); the differential filtering method uses the transmittance of the filter material Poor characteristics Realize the segmental integral measurement of the energy spectrum, which is relatively simple to use, but limited by the number of filters, the resolution of the energy spectrum is very poor; compared with other existing energy spectrum measurement methods, crystal spectroscopy can directly obtain X-rays The diffraction intensity distribution of the measured results can be obtained by less mathematical processing of the measurement results, and the resolution of the energy spectrum is relatively high

However, there are still some problems in the existing crystal spectroscopic method, mainly that the rocking curve of the crystal for continuous energy is difficult to be measured experimentally, and the reliability of the theoretically calculated rocking curve is difficult to verify, and the diffraction efficiency of X-rays increases with the increase of X-ray energy. drop, the measurement efficiency is very low

Images