[X-ray hardening correction for ICT in testing workpiece].

Since energy spectrum of X-ray is polychromatic source in X-ray industrial computerized tomography, the variation of attenuation coefficient with energy leads to the lower energy of X-ray radiation being absorbed preferentially when X-ray is transmitting the materials. And the higher the energy of X-ray, the lower the attenuation coefficient of X-ray. With the increase in the X-ray transmission thickness, it becomes easier for the X-ray to transmit the matter. Thus, the phenomenon of energy spectrum hardening of X-ray takes place, resulting from the interaction between X-ray and the materials. This results in false images in the reconstruction of X-ray industrial computerized tomography. Therefore, hardening correction of energy spectrum of X-ray has to be done. In the present paper, not only is the hardening phenomenon of X-ray transmitting the materials analyzed, but also the relation between the X-ray beam sum and the transmission thickness of X-ray is discussed. And according to the Beer law and the characteristics of interaction when X-ray is transmitting material, and by getting the data of X-ray beam sum, the relation equation is fitted between the X-ray beam sum and X-ray transmission thickness. Then, the relation and the method of equivalence are carried out for X-ray beam sum being corrected. Finally, the equivalent and monochromatic attenuation coefficient fitted value for X-ray transmitting the material is reasoned out. The attenuation coefficient fitted value is used for product back-projection image reconstruction in X-ray industrial computerized tomography. Thus, the effect caused by X-ray beam hardening is wiped off effectively in X-ray industrial computerized tomography.

[Beam hardening simulated correction research for X-ray TICT in testing composites workpiece].

In X-ray TICT, when X-ray is transmitted in the materal, the phenomenon of energy spectrum hardening takes place, resulting in artifacts. Thus, hardening correction has to be done. In the present paper, the phenomenon of X-ray beam hardening resulting in analyized, and the relation between the X-ray beam sum and the transmission thickness in testing composites workpiece is discussed. According to the Beer law and the characteristics of the interaction between X-ray and the material, and getting the data of X-ray beam sum, the relation equation between the beam sum and transmission thickness is simulated firstly, and testing composites workpiece. Then, the relation and the method of equivalence are carried out between the equivalent transmission thickness and the transmission thickness for X-ray beam sum being corrected for monochromatic ray beam. Finally, the attenuation coefficient beam hardening simulated value for X-ray equivalent monochromatic is reasoned out in testing composites workpiece. Then, the attenuation coefficient simulated value that has been corrected is used for product back-projection reconstruction. Thus, the effect caused by X-ray beam hardening is wipped off effectively in testing composites workpiece.

[Hardening correction model of energy spectrum for X-ray TICT in testing composites workpiece].

In the case of a polychromatic source in X-ray TICT, the variation of attenuation coefficient with energy leads to low energy radiation being absorbed preferentially. In other words, the higher the energy, the 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 is energy spectrum hardening analyzed by theory and the relation stated between attenuation coefficient and transmission thickness in testing composites workpiece, but also the precise accurate theory model for hardening correction of energy spectrum and theory method are reasoned out in testing composites workpiece, which results from Beer's law and the characteristics of X-ray interaction with composites. Then, the attenuation coefficient that has been corrected is used for product back-projection reconstruction. Thus, the effect caused by X-ray beam hardening is wipped out effectively in testing composites workpiece.

[Hardening correction model of energy spectrum for continuous spectrum X-ray ICT].

In the case of a polychromatic 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.