The Measurement And Research Of (5-30) KeV Monoenergetic X-rays

Single-energy X-rays are produced by crystal Bragg diffraction,which has the advantage of continuously adjustable energy and fluence,and is the preferred solution for X-ray detector calibration.In order to establish a(5-30)keV monoenergetic X-ray radiation device,the Bragg diffraction study of crystal monochromator and grating monochromator is carried out.The direction of the emitted monoenergetic X-ray beam required to be invariable when adjusting different Bragg angles for accurately perform detection efficiency calibration.The proposed X-ray calibration device needs to cover an energy range(5-30)keV,and the energy range spans a large range.The energy range includes soft X-ray to hard X-ray.Through the research on the crystal,the optical machine and the rotating platform,the pair is completed.(5-30)keV device construction and performance measurement.At the same time,the design of the(0.5-5)keV device was completed.Since the X-ray energy is easily attenuated in the air below 5 keV,a vacuum environment is required.The specific content of this article mainly includes:(1)Design a new type of rotating platform and laser positioning device,design a new type of mechanical structure to make the crystal and X-ray source linkage,adjust the Bragg angle of the crystal,the X-ray source rotates at 2 angles,and at the same time guarantees the production(5-30)of keV The single-energy X-ray exit position does not change.By measuring the energy spectrum of different target materials,it is obtained that the optical function using the copper target can generate more low-energy photons,and the measured voltage error is within 1%.(2)In order to find crystals with large diffraction rate and stability in the low energy section,the properties of three crystals of LiF,Si111 and Si220 were developed.Three kinds of crystals were obtained by measurement,below 10 keV,(10-20)keV.With(20-30)keV,LiF has the best stability and the largest count.LiF is selected as the crystal of single crystal diffraction.At this time,the stability of the device can be controlled within 1.1%.(3)In order to measure the performance of the(5-30)keV single-energy calibration device,the calibration of the detector is based on the Monte Carlo simulation program,and the geometric model of the silicon drift detector and the high-purity germanium detector is established.The structure is optimized according to the experimental conditions and the material thickness and thickness of the shell,window and crystal of the detector,and an accurate and reliable detector model is obtained to calculate the response of the detector to different energies under the parallel X-ray source.The resulting detection efficiency curve.The efficiency and energy scale of the SDD detector are measured using a dual crystal calibration device to obtain the relationship between energy and the site.(4)For the(5-30)keV single-energy calibration device,fluence measurement,energy spectrum measurement,energy stability measurement,fluence stability measurement,spot size measurement and device monochromatic measurement are performed.The measurement results show that the maximum energy drift is 0.18%,and the fluence stability is within 1.1%.The calculated horizontal length of the spot is 3739.5 microns and the vertical length is 4455 microns.The monochromaticity of the device is controlled within 3%.(5)Finally,some calibration experiments of GECAM detector and solar hard X-ray imager and temperature response characteristics of normal temperature semiconductor detector are introduced.