NEUTRON FIBERS .2. SOME IMPROVING ALTERNATIVES AND ANALYSIS OF BENDING LOSSES

The possible confined propagation of slow (thermal) neutrons along cladded waveguides of small cross section (fibers) is studied, in order to improve a previously published analysis. Quite suitable possibilities for the core of the waveguide could be either Al or Si (or vacuum), so as to allow for confined propagation of neutrons along reasonable lengths, without large scattering and absorption losses. Tentative possibilities for the cladding could be either Ni or Fe. The bending losses are analyzed for a curved neutron fiber in two spatial dimensions. Such bending losses turn out to be completely negligible, except in the case of a small radius of curvature R//c. To quote some typical values, for any fiber diameter between 0. 1 and 1 mu m and reasonable lengths for it (between 5 and 10 cm), bending losses can be neglected other than for R//c less than equivalent to 10 cm.