An 8-inch absorption grating used in cascaded Talbot-Lau interferometers for X-ray phase-contrast imaging

Abstract

Cascaded Talbot-Lau interferometers (CTLI) facilitates X-ray differential phase-contrast imaging (DPCI) by using absorption gratings with large periods. Large-area gratings provide a large field of view (FoV), thus they extend applications of DPCI. However, conventional methods for fabricating such gratings are still costly. We report an 8 inch absorption grating that was fabricated by filling tungsten nanoparticles into grating structures. The fabrication process requires readily available equipment, allowing it to be easily implemented. We experimentally tested these absorption gratings with our X-ray CTLI system, yielding Moiré fringes and multi-contrast images, which demonstrates the effectiveness of our proposed method.

A 800 V β‐Ga2O3 Metal–Oxide–Semiconductor Field‐Effect Transistor with High‐Power Figure of Merit of Over 86.3 MW cm−2

“…In comparison with the DC and pulse output curve, an I D,sat of DC measurement at V G ¼ 0 V is 4.16% lower than the pulse data, illustrating an obvious reduction of self-heating effect (SHE) compared with the SiO 2 /Si substrate, but is still higher than that of the AlN/Si substrate. [32,33] Three-terminal off-state breakdown characteristics were measured at room temperature with the device submerged in Fluorinert solution to avoid the air-induced breakdown. During measurement, the source electrode was grounded and the gate was biased at À30 V to deplete the channel, whereas drain bias was gradually increased until the drain current reaches 1 mA mm À1 or a sudden increase occurs to the drain current.…”

Single-Shot Phase-Contrast Imaging with a Single Grating

“…Alternatively, the limitations mentioned above can be overcome by replacing the phase grating with an absorption grating. In this study, we use a tungsten particle-based absorption grating with a 42 µm period and a 150 µm depth that was reported in reference [24].…”

Metal-assisted chemical etching of high throughput, high aspect ratio critical-angle transmission gratings with vertical and smooth sidewalls

“…Specifically, the diffraction efficiency can be as high as 50% and the bandwidth is very wide; the mass is very low; when used, it is basically perpendicular to the incident light and the required grating area is small; it has low requirements for grating flatness and alignment; it is insensitive to polarization; and by varying the geometrical dimensions of the grating and incident angle, X-rays can be blazed in higher diffraction orders to increase the spectral resolving power. Based on these advantages, the CAT grating has considerable potential application in many fields such as X-ray spectroscopic telescopes in astronomy, 4,5) plasma diagnosis in laser inertial confinement fusion, 6,7) X-ray phase contrast imaging, [8][9][10][11] ultraviolet filtration, 12,13) neutral mass spectroscopy, 14) and soft X-ray polarimetry instruments. 15) The geometry of CAT gratings is very demanding, and silicon is the only available fabrication material currently identified.…”