High contrast neutron radiography with optical devices in Kyoto University reactor

The high-contrast neutron radiography has been performed at a VCN guide (VCN) and a supermirror cold neutron guide (CN-3) in Kyoto University Reactor. The large absorption cross-section of very low-energy neutrons can show a slight change of sample which thermal neutrons can not show. The effectiveness is shown in the fields of botany, agriculture and industrial researches. A new spectrum change option using high Qc supermirror (m=4) is attached. It can change the upper limit of the energy of exposure neutrons by reflections, and gives a high flexibility of the experimental condition.