Bacescu, D.M. Berman, L. Hulbert, S. Ocko, B. Yin, Z. JACoW Publishing Geneva, Switzerland 2673-5520 978-3-95450-229-5 10.18429/JACoW-MEDSI2020-WEPC12 English 330-332 detector vacuum experiment scattering operation Contribution to a conference proceedings 2021 2021-10 https://doi.org/10.18429/JACoW-MEDSI2020-WEPC12 https://jacow.org/medsi2020/papers/wepc12.pdf Open Platform and Liquids Scattering (OPLS) is a new experimental station recently built and currently being commissioned at the Soft Matter Interfaces (SMI) beamline 12-ID at NSLS-II. The new instrument expands SMI’s beamline scientific capabilities via the addition of X-ray scattering techniques from liquid surfaces and interfaces. The design of this new instrument, located inside the 12-ID beamline shielding enclosure (hutch B), is based on a single Ge (111) crystal deflector, which bounces the incident x-ray beam downward towards a liquid sample which must be maintained in a horizontal orientation (gravity-driven consideration). The OPLS instrument has a variable deflector-to-sample distance ranging from 0.6 m to 1.5 m. X-ray detectors are mounted on a 2-theta scattering arm located downstream of the sample location. The 2-theta arm is designed to hold up to three X-ray detectors, with fixed 2-theta angular offsets, each dedicated to a different X-ray technique such as X-ray reflectivity, grazing-incidence X-ray scattering, and small- and wide-angle X-ray scattering. Currently, the OPLS experimental station intercepts the SMI beam that otherwise propagates to the experimental endstation located in hutch C and can be retracted to a ’parking’ position laterally out of this beam to allow installation of a removable beam pipe that is needed to support operations in hutch C. The design of OPLS is flexible enough to quickly adapt to a planned future configuration of the SMI beamline in which a OPLS is illuminated separately from the main SMI branch via a second, canted undulator source and a separate photon delivery system. In this future configuration, both branches will be able to operate independently and simultaneously.