Measurement of Neutron Spatial Distribution Inside of a Concrete Shield Using Activation Foil and Imaging Plate Technique

The spatial distribution of neutrons inside the concrete shield of KENS were measured by the combined use of activation detectors and an imaging plate. Aluminium and gold foils were used for neutron flux measurements of both high- energy and thermal neutrons, respectively. The obtained results concerning attenuation of the high-energy neutron flux show a good agreement with results obtained by a Monte-Carlo simulation using the MARS14 code. It is concluded that the method, which combined the use of activation detectors and an imaging plate, was very useful to measure the activity of many pieces of the detector simultaneously without any efficiency or decay correction. A wide dynamic range and a high sensitivity are also merits of this method.