连续谱X射线在ICT中的能谱硬化修正模型

Hardening Correction Model of Energy Spectrum for Continuous Spectrum X-Ray ICT

X射线ICT中,由于连续谱X射线源在穿过物质时,能量较低的射线优先被吸收,也即较高能量的X射线的衰减系数比较低能量的X射线的衰减系数小,射线随透射厚度增大,变得更易穿透,也就是发生了能谱硬化现象。如不加修正,必引起赝像。文中对能谱硬化现象进行实验和理论上的分析,探讨了在均匀物质中,X射线的衰减系数与透射厚度的关系,提出新的能谱硬化修正方法和严谨精确的能谱硬化修正模型。

In the case of a polyehromatic source in X-ray ICT, the variation of attenuation coefficient with energy leads to low energy radiation being absorbed preferentially. In other words, the higher the energy, the more lower the attenuation coefficient. With the transmission thickness augmenting, it is easier for X-ray to transmit the matter. The phenomenon is energy spectrum hardening. Thus, hardening correction has to be done. In the present paper, not only energy spectrum hardening is analyzed by experiment and theory and the relation is stated between attenuation coefficient and transmission thickness, but also the new theory method and the precise accurate theory model for hardening correction of energy spectrum are proposed.