Development of the grating phase neutron interferometer at a monochromatic beam line

Recently, it has been demonstrated that a shearing type interferometer, using precision silicon gratings, enables one to image the gradient of neutron phase shift through an object and retrieve the phase via a simple one-dimensional integration of the gradient. To fully explore this new technique for potential future cold neutron imaging stations at the National Institute of Standards and Technology and the Korea Atomic Energy Research Institute, we have developed a prototype phase imaging station at a monochromatic cold neutron beamline in the NCNR neutron guide hall. We have designed the silicon gratings for a neutron wavelength of 0.44 nm and fabricated them using the state-of-the-art nanofabrication facility at the NIST Center for Nanoscale Science and Technology. Here we will discuss the experimental apparatus, as well as the recent experimental results obtained with this prototype apparatus. We will also present the data analysis method used for the phase retrieval, and discuss the accuracy of the method as well as the measurement sensitivity obtained using this method.