A new Diffractometer for Studies of Liquid - Liquid Interfaces

We have designed a novel, dedicated diffractometer for surface x-ray scattering studies of liquid - liquid and liquid-gas interfaces for the PETRA III High Resolution Diffraction Beamline. Using a double crystal beam-tilter in Bragg geometry this new instrument enables reflectivity and grazing incidence diffraction investigations without moving the sample, which is mechanically decoupled from the rest of the diffractometer. This design minimizes external excitation of surface vibrations, a key prerequisite for studies of liquid interfaces. The instrument operates over the energy range 6.4 keV to 30 keV, the higher energy range being optimal for penetration through liquid sample environments. Vertical momentum transfer up to q(z) = 2.5 A(combining ring above)(-1) and lateral q|| up to 4 A(combining ring above)(-1) will be available.