Design of a horizontal neutron reflectometer for the European Spallation Source

A design study of a horizontal neutron reflectometer adapted to the general baseline of the long pulse European Spallation Source ESS is presented. The instrument layout comprises advanced solutions for the neutron guide, high resolution pulse shaping and beam bending onto a sample surface being thoroughly adjusted to the properties of the ESS. The length of this instrument is roughly 55 m, enabling amp; 948; amp; 955; amp; 955; resolutions from 0.5 to 10 . The incident beam is focused in horizontal plane to boost measurements of sample sizes of 1 1 cm2 and smaller with potential beam deflection in both downward and upward directions. The primary range of neutron wavelengths utilized by the instrument is 2 7.1 . If the wavelength range needs to be extended, then this is possible by utilizing only every second third, fourth pulse by suppressing all other pulses by the chopper system and thus increase the longest usable wavelength to 12.2 17.3, 22.4 . Angles of incidence can be set between 0 and 9 with a total accessible q range from 4 10 amp; 8722;3 amp; 8722;1 up to 1 amp; 8722;1, while the amp; 948; amp; 952; amp; 952; resolution can be freely set. The instrument operates in both amp; 952; amp; 952; free liquid surfaces and amp; 952; 2 amp; 952; solid liquid, air solid interfaces geometries. The experimental setup will in particular enable direct studies on ultrathin films d amp; 8776;10 and buried monolayers to multilayered structures of up to 3000 total thickness. The horizontal reflectometer will further foster investigations of hierarchical systems from nanometer to micrometer length scale the latter by off specular scattering , as well as their kinetics and dynamical properties, in particular under load shear, pressure, external fields . Polarization and polarization analysis as well as the GISANS option are designed as potential modules to be implemented in the generic instrument layout. The instrument is highly flexible and offers a variety of different measurement modes. With respect to its mechanical components the instrument is exclusively based on current technology. Risks of failure for the chosen setup are minimu