GINA - A Polarized Neutron Reflectometer at the Budapest Neutron Centre

TL;DR

GINA is a newly installed polarized neutron reflectometer at Budapest Neutron Centre, designed for studying magnetic and non-magnetic thin films with high sensitivity and advanced polarization capabilities.

Contribution

It introduces a novel neutron reflectometer with enhanced polarization, focusing, and detection features for magnetic and non-magnetic surface studies.

Findings

Achieved reflectivity as low as 3x10^-5

Doubled reflected intensity through vertical focusing

Facility is operational and open for international users

Abstract

The setup, capabilities and operation parameters of the neutron reflectometer GINA, the recently installed "Grazing Incidence Neutron Apparatus" at the Budapest Neutron Centre, are introduced. GINA, a dance-floor-type, constant-energy, angle-dispersive reflectometer is equipped with a 2D position-sensitive detector to study specular and off-specular scattering. Wavelength options between 3.2 and 5.7 {\AA} are available for unpolarized and polarized neutrons. Spin polarization and analysis are achieved by magnetized transmission supermirrors and radio-frequency adiabatic spin flippers. As a result of vertical focusing by the five-element (pyrolytic graphite) monochromator the reflected intensity from a 20x20 mm sample has doubled. GINA is dedicated to studies of magnetic films and heterostructures, but unpolarized options for non-magnetic films, membranes and other surfaces are also provided. Shortly after its startup, reflectivity values as low as 3x10-5 have been measured on the instrument. The facility is now open for the international user community, but its development is continuing mainly to establish new sample environment options, the spin analysis of off-specularly scattered radiation and further decrease of the background.