| Hauptseite > Publications database > Structural, electrical and magnetic properties of reactively DC sputtered Cu and Ti thin films. Application to Cu/Ti neutron supermirrors for low spin-flip applications |
| Journal Article | IMPULSE-2024-00020 |
; ; ; ;
2024
North-Holland Publ. Co.
Amsterdam
Please use a persistent id in citations: doi:10.1016/j.nima.2023.169005
Abstract: Neutron guides are smooth-wall tubes whose inner surfaces are coated with neutron reflecting materials. When a neutron beam hits the surface of the guide at a shallow enough angle below a critical angle, θc, it undergoes total reflection and neutrons travel in the guide without loss. That way, cold and thermal neutrons can be transported to instruments that may be at hundreds of meters from the source. Supermirrors (SMs) were first devised by Mezei and Dagleish [1]. They consist of a stack of thin bilayers of slowly varying bilayer thickness so that at a given angle of incidence the Bragg condition is fulfilled for a wide range of de Broglie wavelength of incident neutrons, or – for a given wavelength – the angular range of reflectivity close to unity is extended beyond the critical angle of total reflection of the best reflecting material, nickel, by a number of times, called the m factor of the SM [2]. The critical angle of total reflection of the SM (θc,SM) becomes θc,SM = θc,Ni·m = 0.099·λ·m, being the angle in degrees and the wavelength λ in Å. Therefore, supermirrors are widely used in neutron guides to increase the transported neutron flux.
Keyword(s): Instrument and Method Development (1st) ; Instrument and Method Development (2nd)
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