Haas, E. Abeykoon, M. Buda, S. Dooryhee, E.D. Ghose, S. Stelmach, C. Trunk, J.T. JACoW Publishing Geneva, Switzerland 978-3-95450-207-3 10.18429/JACoW-MEDSI2018-THPH19 English 379-381 THPH19 experiment FEL operation controls GUI Contribution to a conference proceedings 2018 2018-12 https://doi.org/10.18429/JACoW-MEDSI2018-THPH19 http://jacow.org/medsi2018/papers/thph19.pdf The X-ray Powder Diffraction (XPD) and Pair Distribution Function (PDF) beamlines located at the 28-ID beam port at NSLS-II require a means for safely supplying, containing, and exhausting hazardous gases to and from experimental samples. These beamlines plan to use a wide range of flammable, toxic, and reactive gases for in-situ studies of catalytic and chemical reactions. Since many of the gases are hazardous, a low-cost, robust means is needed to safely supply gases to samples, position the samples quickly, accurately, and remotely, collect scattered X-rays over a wide-angle without distortion, and exhaust the gases safely. Ideally, the sample environment should also allow rapid sample set-up and change-out. The PDF/XPD system includes a sample holder, internal beam stop, sample chamber, and stages that provide eight degrees of freedom. A specially-designed window is also included for maximum X-ray transmission at minimum cost. Sensors, flow metering devices, and circuitry are included to provide proper purging, control hazardous and dilution gas flows, and integrate all of the safeguards needed to assure safe operation.