Measurements and simulations of neutron transport characteristics of multi-capillary fibers as a function of neutron wavelength

A multi-capillary fiber device is used for transporting the neutrons. For a pulsed neutron source the energy dependence is important, but experimental results have not agreed with simulation results. Therefore, we performed experimental studies and simulation calculations to get wavelength-dependent information at several capillary diameters and also at several curvature of the fibers. The experimental results showed that from 30 to 70 μm capillary fibers had no systematic difference in the transmission intensity and there exist difference between the experimental and the simulation results. It is found that the difference was partially explained by introducing a wave-like distortion to the fiber form.