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Moreover, we demonstrate the reflection of fragile He3 from a square wave grating via the half-planearray diffraction. In the future, by designing a super-periodic half-plane array with a small half-plane period and a large grating super-period, it will be possible to study diffraction of fragile van der Waalsclusters such as He2 and He3. The combination of half-plane array and super-period grating will lead to diffraction at enhanced reflection probabilities as compared to previous experiments.