Production of ultra-cold neutrons in solid α-oxygen
Technische Universität München, Physik Department - James-Franck-Str. 1, D-85748 Garching, Germany, EU
2 Institut Laue Langevin - 156X, F-38042 Grenoble CEDEX, France, EU
3 Dipartimento di Fisica and CNR-IOM, Università di Perugia - I-06123 Perugia, Italy, EU
Accepted: 26 October 2011
Our recent neutron scattering measurements of phonons and magnons in solid α-oxygen have led us to a new understanding of the production mechanism of ultra-cold neutrons (UCN) in this super-thermal converter. The UCN production in solid α-oxygen is dominated by the excitation of phonons. The contribution of magnons to UCN production becomes only slightly important above E>10 meV and at E∼4 meV. Solid α-oxygen is in comparison to solid deuterium less efficient in the down-scattering of thermal or cold neutrons into the UCN energy regime. Nevertheless, the lower efficiency might be compensated by the larger mean free-path of UCN in oxygen with respect to deuterium.
PACS: 28.20.Cz – Neutron scattering / 75.50.Ee – Antiferromagnetics
© EPLA, 2011