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X-ray gratings

Meet us at:
SRI 2018 (International Conference on Synchrotron Radiation Instrumentation)
11-13.6.2018, Taipei International Convention Center

Recent updates:
X-ray optic products posters (For SRI 2018, 6.2018, coming soon))
X-ray optic products brochure (For XNPIG 2017, 9.2017)

1. X-ray imaging by Talbot Interferometry

(a) X-ray images you can obtain
Using X-ray Talbot interferometer, differential phase contrast images and visibility contrast (dark field or small-angle scattering contrast) images can be obtained in addition to ordinary X-ray absorption images on one set-up, which allows you to get far more information of the inside and surface of the sample than the conventional X-ray absorption imaging method.
In the example images below, you will find the difference of the obtained information between the different modalities (absorption contrast and differential phase contrast) of the same sample taken at the same time.


Absorption contrast image (scale bar: 2.5 mm)

Differential phase contrast (scale bar: 2.5 mm)

Sample: SD card with scratches. Taken at BL14-C Photon Factory, Japan


(b)Talbot Interferometer: Multi modal X-ray imaging method using X-ray gratings

By adding a source grating (absorption grating) G0 to a Talbot interferometer set-up, coherent X-ray can be obtained from a standard X-ray tube (Talbot-Lau interferometer).



2. X-ray gratings from Karlsruhe, Germany

Karlsruhe Institute of Technology (KIT)/IMT and its spin-off company microworks GmbH have a long experience in the fabrication of micro structures by X-ray lithography and electroplating (LIGA process) and they supply worldwide high aspect ratio X-ray gratings necessary for Talbot interferometer.


Left: High aspect ratio absorption grating. AR > 80 available depending on the period.

Right: Bent absorption grating to avoid shadow effects. Delivered mounted on a holder.

(a) Grating structure examples
X-ray gratings are made by copying the precision structure of an X-ray mask onto the resist on the substrate, followed by electroplating done between the gaps of the X-ray exposed resist lamellae. Grating layout designs can either be chosen from existing masks or be newly made for your special set-up.


Metal height (examples)200 μm4.0 μm
Period (metal + space)4.8 μm3.57 μm
MaterialAuNi

Examples of existing period designs, subject to change



(b) Grating standard specifications

Here are some examples of grating specifications and some options which do not require special development.

Absorber / Phase shift materialAu, Ni or polymer resist
Substrate Standard: Si wafer (200 or 550 µm)
Optional: Low X-ray absorption materials like graphite and polyimide.
Structured area Standard: 50 mm x 50 mm,70 mm diameter.
Optional: 100-140 mm diameter, 100 mm x 90 mm. Further larger area by stitching some plates.

3. Manufacturers and recent results

(a) Suppliers
Karlsruhe Institute of Technology (KIT)/IMT and its spin-off company microworks GmbH supply X-ray gratings for Talbot and Talbot-Lau interferometers not only with standard specifications described above but also with ones based on the customers' special requirements. ASICON Tokyo Ltd. serves as their local distributor in Japan, South Korea and Taiwan.

(b) High Aspect Ratio (High AR) structures
KIT/IMT and microworks GmbH are two of the world's top authorities in the fabrication of high aspect ratio polymer and metal structures using X-ray lithography and electroplating techniques. With these techniques (LIGA Process), X-ray gratings with both a narrow period and high aspect ratio have been realised.

(c) Very narrow period gratings

X-ray gratings with a very narrow period of 1.0-2.0 µm have been realised within a limited structured area.


X-ray grating with a lamella width of 0.5 µm


(d) Imaging examples
Internal link (Japanese): X-ray images of some samples taken with X-ray gratings fabricated by microworks GmbH.