Analysis of polychromaticity effects in X-ray Talbot interferometer.
The influence of polychromaticity of the X-ray source on the performance of an X-ray Talbot interferometer applied for phase-contrast imaging is analyzed through numerical simulations based on the Fresnel diffraction theory. The presented simulation results show that the visibility of the self-image is fairly insensitive to the source polychromaticity and explain why the interferometer could be well combined with polychromatic X-ray sources in recent experiments. Furthermore, the self-image with a high visibility can be obtained under polychromatic illumination even at a high-order fractional Talbot distance. This fact implies that the acquired image quality for phase measurements can be improved, since the primary signal for phase measurement is proportional to the inter-grating distance. Finally, we mention that the results are also valid for Talbot-Lau interferometer and scanning double-grating configuration.
Wang
Zhili
Z
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Zhu
Peiping
P
Huang
Wanxia
W
Yuan
Qingxi
Q
Liu
Xiaosong
X
Zhang
Kai
K
Hong
Youli
Y
Zhang
Huitao
H
Ge
Xin
X
Gao
Kun
K
Wu
Ziyu
Z
D003952:Diagnostic Imaging / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007368:Interferometry / Q000379:methods*; D008962:Models, Theoretical; D014965:X-Rays