Date of Approval 2017/6/26
Approver Takenao Shinohara
Date of Report 2017/6/1

Project No. 2016A0262

Name of Instrument scientist

Title of experiment
Name of Instrument/ BL No.
Name of principal investigator

Date of Experiment

Affiliation

Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
Name of sample(s) and chemical formula, or compositions including physical form.

Experimental method and results.

If you failed to conduct experiment as planned, please describe reasons.

The phase imaging setup using Talbot-lau interferometry system was constructed at the upstream sample positionof the RADEN instrument. The illustration of experimental setup is shown in Fig. 1. Three gratings (G0, G1, G2)
are placed in a proper distance and each grating position was finally decided to maximize the visibility of moire
pattern obtained by the neutron 2D detector using EMCCD camera. At first, we tested 5 G2 gratings which are
made by the oblique evaporation technique of Gd. According to the previous test experiment, we can evaluate
both the effective thickness of Gd layer and approximate duty cycle of grating from the wavelength dependentneutron transmission. Then, we selected a G2 grating which had highest visibility and good spatial homogeneityand used to the following phase imaging experiments.
The obtained image without sample shown in Fig.2 (left) indicates clear moire fringe pattern. Change in thevisibility of moire pattern against the neutron wavelength was studied and we found that moire pattern appearedalmost whole wavelength range from 1.5 to 8.5 Å and the maximum visibility was obtained at the wavelength of
5 Å, which was the designed value of present phase imaging apparatus (Fig. 2 (right)).

Experimental method and results (continued)
n addition, at the wavelengths, which are half-integer of optimal wavelength, the visibility became about the halfof maximum value. This agreed well with the expectation from the Talbot-Lau condition. This result clearly
indicated the availability of broad wavelength range neutron beam for neutron phase imaging.
Fig. 1 Illustration of the experimental setup of neutron
phase imaging. Three gratings are placed with a proper
spacing, and 2D neutron detectors of both camera-type andcounting –type were used for the experiment.

Fig. 2 right: observed moire
pattern without sample, left:
wavelength dependence ofvisibility.

Thevalue

pindicates Talbot-order.

Then, we placed several metal rods in front of the G1 grating as the sample, and performed fringe-scan to obtainabsorption image, differential phase image, and visibility image as shown in Fig. 4. It is obviously found that Al
rod can be clearly seen in the differential phase image while it was not recognized in the absorption image.
Moreover, the difference in the sign of scattering lengths between Al and Ti was observed as the change in thedistribution of .

Fig. 3 obtained images with metallic rod samples. Right: absorption image, center: differential phase image, and left: visibility
image at the wavelength of 4.3 Å.

The wavelength dependence of differential phase distribution, we could confirm thatsquare of wavelength and thatwas proportional to thewas wrapped when it went over 2 . This result indicates that by means ofanalyzing wavelength dependence of differential phase j makes it possible to unwrap the phase shift and toevaluate spatial distribution of phase information precisely.