Dual-energy analysis grating

Abstract

The invention relates to a dual-energy analysis grating. The dual-energy analysis grating mainly comprises high-energy grate bars and low-energy grate bars. The high-energy grate bars can be used for converting high-energy X rays into visible light and screening low-energy X rays, and the low-energy grate bars can be used for converting the low-energy X rays into the visible light and screening the high-energy X rays. The grating is made from caesium iodide (CsI) and bismuth (Bi). According to the dual-energy analysis grating, the defects of the traditional analysis gratings are overcome, and the dual-energy analysis grating is used for converting the X rays of different energies instead of stepping; by applying the dual-energy analysis grating to a dual-energy imaging system, steps of imaging are reduced, the requirements on mechanical accuracy are lowered, and the imaging system is simplified.

Description

technical field [0001] The patent of the present invention relates to the field of X-ray imaging, and is an analysis grating applied to X-ray symmetry imaging systems. Background technique [0002] X-ray imaging technology is widely used in materials science, life science, industrial inspection and other fields, and is an indispensable and important tool for studying the internal structure of substances [1] . The interaction between X-rays and matter can be expressed by the complex refractive index, that is, n=1-α+iβ, where β is the absorption factor and α is the phase factor, which respectively represent the amplitude and phase changes of X-rays after passing through the object [2] . Traditional X-ray detection is based on the difference in the absorption of X-rays by substances, but substances composed of light elements such as C, H, O, and N have weak absorption of X-rays and cannot be effectively imaged. [3] . For matter composed of light elements, the change in X-ra...

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Problems solved by technology

The phase extraction algorithm of grating phase contrast imaging used the multi-step shift method in the early stage, and Chen Bo proposed the two-step phase shift method in 2008 [11] , in 2010 Liu Xin proposed a two-step arbitrary displacement method [12] , although the number of grating displacement steps is getting smaller and smaller, the imaging system still needs a precise stepping platform, which increases the complexity of the system. Multiple steps and exposures make the imaging efficiency low and increase the radiation dose of the measured object

The positive and negative projection method proposed by Zhu Peiping in 2010 does not require grating stepping [13] , this method has made a breakthrough in phase-contrast CT imaging, but it is very difficult to realize that the object or detector needs to be rotated precisely in the imaging system

This method reduces the number of steps and improves imaging efficiency, but it requires very high step accuracy, and step errors can easily lead to a decrease in imaging quality

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