Matter-wave near-field interferometric experiments require interference contrast as high as possible in order to extractinformation from the interference patterns. One of the tasks to accomplish this requirement is to align the distancesbetween gratings and detection. We present here a method for this precision alignment. An electron beam as a matterwavesource, a diffraction grating, and mask grating were used in this study. The simulations show that the longitudinalscanning of the mask grating with the detection can specify the exact location of the near-field or so-called Talbotdistance with the condition of using the gratings with small open fractions. Therefore, the various open fractions weredone in the calculation. Due to the lack of commercial gratings with small open fractions, a technique of two overlappinggratings can be applied for changing arbitrary grating shapes and open fractions. We conclude that smaller open fractionof the gratings gives better longitudinal alignment. The results show that the Talbot distance is located at the highestthroughput behind the gratings. The present study can provide a method for implementing matter-wave diffractionexperiments in the future.
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