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TY - CONF AU - Xu, S. AU - Fischetti, R. AU - Makarov, O. AU - Stepanov, S.A. AU - Venugopalan, N. ED - Casas, Joan ED - Schaa, Volker RW ED - Costa, Isidre ED - López, David ED - Prieto, Montserrat TI - Mechanical Design of New Dual Pinhole Mini-Beam Collimator With Motorized Pitch and Yaw Adjuster Provides Lower Background for X-Ray Crystallography at GMCA@APS J2 - Proc. of MEDSI2016, Barcelona, Spain, 11-16 September 2016 CY - Barcelona, Spain T2 - Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation Conference T3 - 9 LA - english AB - The GM/CA developed, quad-mini-beam collimator[*,**], advanced rastering and vector data-collection software tools[***], have enabled successful data collection on some of the most challenging problems in structural biology. There are two main sources of X-ray scattering (besides the sample) that reach the detector, contribute to back-ground and limit data resolution. These are scattering within the collimator that escapes the exit aperture and air-scattering of the direct beam before it terminates in the beamstop. Scattering from the collimator can be reduced by decreasing the exit aperture size. A quad mini-beam collimator was built consisting of 5/50, 10/70, 20/100 and 150/300 µm beam defining/exit aperture combination, respectively. Previous collimators were positioned in the X-ray beam by two motorized translational motions and two manual angular adjustments via a kinematic mount. Due to reduced tolerance in the new design, aligning each of the pin-hole combinations to high-precision required motorizing both translational and angular motions. Design and con-struction of the improved mini-beam collimator and the extent of background reduction will be discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 387 EP - 389 KW - ion KW - background KW - scattering KW - photon KW - software DA - 2017/06 PY - 2017 SN - 978-3-95450-188-5 DO - doi:10.18429/JACoW-MEDSI2016-THAA03 UR - http://jacow.org/medsi2016/papers/thaa03.pdf ER -