AMOR — the time-of-flight neutron reflectometer at SINQ/PSI

Abstract

The apparatus for multioptional reflectometry (AMOR) at SINQ/PSI is a versatile reflectometer operational in the time-of-flight (TOF) mode (in a wavelength range of 0.15 nm < λ < 1.3 nm) as well as in the monochromatic (θ- 2θ) mode with both polarized and unpolarized neutrons. AMOR is designed to perform reflectometry measurements in horizontal sample-plane geometry which allows studying both solid-liquid and liquid-liquid interfaces. A pulsed cold neutron beam from the end position of the neutron guide is produced by a dual-chopper system (side-by-side) having two windows at 180‡ and rotatable with a maximum frequency of 200 Hz. In the TOF mode, the chopper frequency, width of the gating window and the chopper-detector distance can be selected independently providing a wide range of q-resolution (Δq/q = 1–10%). Remanent FeCoV/Ti:N supermirrors are used as polarizer/analyzer with a polarization efficiency of ∼97%. For the monochromatic wavelength mode, a Ni/Ti multilayer is used as a monochromator, giving ∼50% reflectivity at a wavelength of 0.47 nm. In the present work, a detailed description of the instrument and setting-up of the polarization option is described. Results from some of the recent studies with polarized neutrons and measurements on liquid surfaces are presented.