The Measurement And Research Of (10-200) KeV Monoenergetic X-Rays

Radionuclides decay?medical and industrial will produce X(?)rays. If too much contact with these rays, it will cause some damage to the human body. X(?) rays is colorless and odorless and difficult to detect. We need to use special instruments to measure it. A variety of detectors will be used to Measure X(?) rays. So it is particularly important to the linear detector energy, detectable efficiency calibration.We use radioactive sources to calibrate the detector traditionally. But the energy of radioactive sources is not adjustable. It can not be measured detection efficiency of absorption edge, and generally higher-ray energy.Therefore, the study of single energy X-rays is more realistic.To meet the needs of single-energy X-ray studies, China Institute of Metrology has initially set up a single energy X-ray source based on the X-ray machine + spectral body. The work on this basis, by splitting the body structure is designed to improve the T extended the original single-energy X-ray energy range of the device, and the single-energy X-ray devices improved detailed testing research. The thesis work includes:(1) We improved spectral structure body T and extends the monochromatic X-ray source energy range to(10-165) ke V. The X-ray spectrum of X-ray machine produced is a continuous X-ray spectrum, having a large energy range ? By using diffraction of double-crystal monochromator for the X-ray spectrum of X-ray machine produced can produce monochromatic X-rays, by double-crystal monochromator can obtain monochromatic X-rays.Double crystal monochromator contain T structure and Precision angle instrument. Precision angle instrument can change the angle of diffraction and T structure is the diffractive structure section. Double crystal monochromator T structure results showed improvement:Using Si(111) crystal can be obtained(10-47.5) ke V energy in a monochromatic X-ray; Using Si(220) crystals can be obtained(16.5-165) ke V energy monoenergetic X-rays, so the set of devices that can be obtained by replacing the crystal(10-165) ke V monoenergetic X-rays.(2) We measurement and research the energy, fluence, and monochromatic photon distribution of monochromatic X-ray source(40-165 ke V). By using standard calibration sources and Monte Carlo simulation to obtain high-purity germanium detectors(1-300)ke V detection efficiency at parallel monoenergetic photons, making it the experimental standard detectors. Further using the standard detector measured(10-165) ke V monochromatic X-ray fluence curve. GEM detector measure monochromatic X-ray source spot size(about 8mm).Through the spectrum measurement and analysis, found that a monochromatic X-ray monochromatic as energy increases. This is due to the diffraction energy with the change of Bragg diffraction peaks affected by adjusting the X-ray tube voltage and tube current can be adjusted number of photons mono-energetic X-rays, in the same tube voltage, monochromatic X-ray photons proportional to the number of tube current, the tube voltage and the impact on the number of photons monoenergetic X-ray bremsstrahlung spectrum with different tube voltages, but also to the number of photons with the T structure will cast angle changes, when two parallel to the crystal reached, the maximum count rate.This research work is to increase the single-energy X-ray apparatus Applicability(a wider range of energy), rich in monoenergetic X-ray device performance data which provide important support.