Neutron fibres: a three-dimensional analysis of bending losses

The confined propagation of slow neutrons along waveguides of a small cross section (fibres), discussed theoretically some time ago and demonstrated experimentally by other authors later, is analysed further. Motivated by those experiments, a three-dimensional quantum-mechanical treatment of the ass...

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Detalhes bibliográficos
Autor: Calvo Padilla, María Luisa
Formato: artículo
Fecha de publicación:2000
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/59066
Acesso em linha:https://hdl.handle.net/20.500.14352/59066
Access Level:acceso abierto
Palavra-chave:535
Optics
Óptica (Física)
2209.19 Óptica Física
Descrição
Resumo:The confined propagation of slow neutrons along waveguides of a small cross section (fibres), discussed theoretically some time ago and demonstrated experimentally by other authors later, is analysed further. Motivated by those experiments, a three-dimensional quantum-mechanical treatment of the associated bending losses is presented. An approximate (two-parameter) formula is derived for the transmission coefficient Upsilon of the curved fibre, which displays its explicit dependence on the curvature radius Rcu, for 0<Rcu< + ∞. By adjusting one of the parameters (b), consistently with the theoretical analysis, and by fitting the other, the approximate formula describes all measured data for Upsilon. The parameter b (which accounts for the experimental data for Upsilon at large Rcu) allows the estimation of the number of effectively excited modes in the fibre.