Neutron interferometer with very thin lamellae

We describe the manufacturing and testing of a monolithic perfect crystal i nterferometer with very thin lamellae, optimized for neutron phase contrast imaging where high spatial phase resolution is required. The two main char acteristics of our new interferometer design are thin lamellae (t = 0.56 mm .) for beam splitter S and analyzer A, and mirrors M1, M2 of twice the thic kness (t(M) = 1.12 mm) of S and A. The different stages of crystal preparat ion and the successful test with X-rays are reported.