The design of neutron radiography collimators is a well-established art, but many facilities have been designed without due regard for the body of experience that already exists. The principles and practice of neutron radiography collimator design are described, with emphasis on the importance of careful selection of materials.
This paper describes an approach to the successful design of neutron radiography collimators. Attention is given to physical concepts involved, and to the ‘rules of thumb’ that permit a simplified design approach. Collimators for neutron radiography must be designed with the requirements of the emergent neutron beam clearly in mind. In turn, the requirements placed upon the beam depend very strongly upon the details of the target application. For example, the characteristics of a neutron beam optimized for the examination of irradiated nuclear fuel will be very different from those of a beam intended for the examination of typical industrial components. The approach taken to collimator design here involves an examination of the basic components of a neutron radiography collimator, followed by the balancing of a variety of beam-design features to allow the design criteria to be met. The materials that are generally available for collimator construction are also described.
Read the complete article here.