Upgraded CT imaging sees the inner structures of dense materials with micron level resolution

Many X-ray sources for computed tomography (CT) imaging lack the photon energy and flux required for hyperfine nondestructive testing, a technique for resolving complex inner structures of objects with applications ranging from biology to materials science. As a major step toward enabling hyperfine nondestructive testing for CT imaging, Ma et al. developed a technique based on all-optical inverse Compton scattering (AOCS).

Using their method to look at copper pins on an aluminum tube, the group was able to observe resolutions of 16 micrometers, but they numerically demonstrated its applicability all the way down to 4.5 μm.

Generally, the X-ray sources used for this type of imaging are limited by their low photon brightness. A significant improvement in this realm is what enabled the researchers to access such impressive resolutions in their image reconstructions, which are taken from multiple pulsed X-ray scans.

“In our research, high brightness AOCS with about 14 μm source size and about 70 keV photon energy was experimentally realized, and then adopted in high resolution CT imaging for the first time, providing high resolution reconstruction of a test object,” said author Wei Lu. “This work shows clearly the potential of AOCS for high-resolution CT applications.”

The system’s compact size and high imaging resolution are promising for widespread application. With additional improvements in source size and photon energy, the method can be used for anything from biological sample imaging to aircraft turbine diagnosis and everything in between.

“Both conditions can be reached with further optimization,” Lu said.

Source: “Region-of-interest micro-focus computed tomography based on an all-optical inverse Compton scattering source,” by Yue Ma, Jianfei Hua, Dexiang Liu, Yunxiao He, Tianliang Zhang, Jiucheng Chen, Fan Yang, Xiaonan Ning, Zhongshan Yang, Jie Zhang, Chih-Hao Pai, Yuqiu Gu, and Wei Lu, Matter and Radiation at Extremes (2020). The article can be accessed at https://doi.org/10.1063/5.0016034 .

This paper is part of the Progress in Matter and Radiation at Extremes in China Collection, learn more here .