Development of multi-pinhole collimator for large imaging area with high spatial resolution

A multi-pinhole collimator system, which is effective for enlarging imaging area with high spatial resolution, has been demonstrated on Cold Neutron Radiograph Facility at JRR-3M in JAEA. The multi-pinhole collimator system consists of a multi-pinhole aperture and an overlap-cutter. On neutron beam from the multi-pinhole aperture, neutrons from each pinhole overlap at the sample position due to beam divergence. In the overlap area, sample images from each pinhole are obtained at a detector and these images look like split images. The overlap-cutter works to cut neutrons contribute to overlap at sample position and enable us to get an image without split. Imaging area was enlarged and sharp image without split was successfully obtained by using the multi-pinhole collimator system.