Our recent neutron scattering measurements of phonons and magnons in solid alpha-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 alpha-oxygen is dominated by the excitation of phonons. The contribution of magnons to UCN production becomes only slightly important above E>10meV and at E ∼ 4meV. Solid alpha-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.
Production of ultra-cold neutrons in solid alpha-oxygen
ORECCHINI, Andrea;
2011
Abstract
Our recent neutron scattering measurements of phonons and magnons in solid alpha-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 alpha-oxygen is dominated by the excitation of phonons. The contribution of magnons to UCN production becomes only slightly important above E>10meV and at E ∼ 4meV. Solid alpha-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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
