This paper review the configurations of grating-based X-ray interferometry for X-ray phase imaging/tomography and describes recent activities for four-dimensional X-ray phase tomography and nanoscopic X-ray phase tomog-
raphy. A multilayer mirror to produce a 10% bandwidth pink beam at 25 keV has been installed at SPring-8 for four-dimensional X-ray phase tomography, and an application to polymer laser ablation is presented. A 100-fold full-field X-ray microscope employing a Fresnel zone plate has been used successfully in combination with a Talbot interferometer to perform nanoscopic phase tomography for a malleal processus brevis of a mouse nine days after birth. Another development using a laboratory-based full-field X-ray microscope in combination with a Lau interferometer is also described.
A high energy X-ray micro-tomography system has been developed at BL20B2 in SPring-8. The available range of the
energy is between 20keV and 113keV with a Si (511) double crystal monochromator. The system enables us to image
large or heavy materials such as fossils and metals. The X-ray image detector consists of visible light conversion system
and sCMOS camera. The effective pixel size is variable by changing a tandem lens between 6.5 μm/pixel and 25.5
μm/pixel discretely. The format of the camera is 2048 pixels x 2048 pixels. As a demonstration of the system, alkaline
battery and a nodule from Bolivia were imaged. A detail of the structure of the battery and a female mold Trilobite were
successfully imaged without breaking those fossils.
We have launched a project to promote grating-based X-ray phase imaging/tomography extensively. Here, two main activities are presented for enabling dynamic, or four-dimensional, X-ray phase tomography and nanoscopic X-ray phase tomography by grating interferometry. For the former, while some demonstrations in this direction were performed with white synchrotron radiation, improvement in image quality by spectrum tuning is described. A preliminary result by a total reflection mirror is presented, and as a next step, preparation of a 10% bandpass filter by a multilayer mirror is reported. For the latter, X-ray microscopes available both at synchrotron radiation facilities and laboratories equipped with a Fresnel zone plate are combined with grating interferometry. Here, a preliminary result with a combination of a Lau interferometer and a laboratory-based X-ray microscope is presented.
A new micro-tomography system for materials science has been developed at BL20B2 in SPring-8. The system enables us
to do stretching, press and twist of materials with a translation stage and two precise rotation stages arranged opposite to
each other. Each deformation can be operated with constant moving rate. The maximum load is about 2 kN because of the
hardness of the precision stages. The X-ray image detector consists of visible light conversion system and sCMOS camera.
The effective pixel size is variable by changing a tandem lens between 2.7 μm/pixel to 13.2 μm /pixel discretely. As a
demonstration of the system, a viscoelastic object was imaged. The experimental conditions are follows, X-ray energy: 25
keV, exposure time: 5 msec, number of projections: 900, single scan time: 7.5 sec, pixel size: 13.2 μm /pixel and field of
view: 27.0 mm x 3.9 mm. The stretching rate was 1 μm /sec to 5 μm /sec. A metastable state such as tensile loading of
viscoelastic materials is possible with this system.
A fast micro-tomography system and a high throughput micro-tomography system using state-of-the-art Complementary Metal Oxide Semiconductor (CMOS) imaging devices have been developed at SPring-8. Those systems adopt simple projection type tomography using synchrotron radiation X-ray. The fast micro-tomography system achieves a scan time around 2 s with 1000 projections, which is 15 times faster than previously developed system at SPring-8. The CMOS camera for fast tomography has 64 Giga Byte on-board memory, therefore, the obtained images must be transferred to a PC at the appropriate timing. A melting process of snow at room temperature was imaged every 30 s as a demonstration of the system. The high throughput tomography system adopts a scientific CMOS (sCMOS) camera with a low noise and high quantum efficiency. The system achieves a scan time around 5 minutes which is three times faster than before. The images quality of the system has been compared to the existing system with Charge-Coupled Device (CCD) camera. The results have shown the advantage of the new sCMOS camera.