Al-Falahat Ala'a M, Kupsch Andreas, Hentschel Manfred P, Lange Axel, Kardjilov Nikolay, Markötter Henning, Manke Ingo
Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, Berlin 14109, Germany.
BAM Federal Institute for Materials Research and Testing, Unter den Eichen 87, Berlin 12205, Germany.
Rev Sci Instrum. 2019 Dec 1;90(12):125108. doi: 10.1063/1.5097170.
In various kinds of radiography, deficient transmission imaging may occur due to backlighting inside the detector itself arising from light or radiation scattering. The related intensity mismatches barely disturb the high resolution contrast, but its long range nature results in reduced attenuation levels which are often disregarded. Based on X-ray observations and an empirical formalism, a procedure is developed for a first order correction of detector backlighting. A backlighting factor is modeled as a function of the relative detector coverage by the sample projection. Different cases of sample transmission are regarded at different backlight factors and detector coverage. The additional intensity of backlighting may strongly affect the values of materials' attenuation up to a few 10%. The presented scenario provides a comfortable procedure for corrections of X-ray or neutron transmission imaging data.
在各种射线照相术中，由于探测器内部因光或辐射散射而产生的逆光，可能会出现透射成像不足的情况。相关的强度不匹配几乎不会干扰高分辨率对比度，但其长程特性会导致衰减水平降低，而这一点常常被忽视。基于X射线观测和一种经验形式，开发了一种用于探测器逆光一阶校正的程序。将逆光因子建模为样品投影对探测器相对覆盖程度的函数。在不同的逆光因子和探测器覆盖情况下考虑样品透射的不同情况。逆光的附加强度可能会强烈影响材料衰减值，最高可达百分之几。所提出的方案为校正X射线或中子透射成像数据提供了一种简便的程序。
