Dfr. Mildner et al., THE NUMBER OF REFLECTIONS FOR NEUTRON TRANSMISSION THROUGH CYLINDRICAL CHANNELS, Journal of applied crystallography, 30, 1997, pp. 324-326
The fraction of trajectories that have a given number of reflections d
uring the passage of a neutron beam through a long cylindrical channel
is determined when the angular divergence of the incident beam is les
s than the critical angle of the inner surface of the channel. This is
useful for estimating the reflectivity from neutron-transmission meas
urements. The results are shown on a universal curve.