Keyword: optics
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TUCPA05 Laser Damage Image Pre-processing Based on Total Variation ion, laser, site, electron 272
  • J. Luo, Z. Ni, X. Xie, X. Zhou
    CAEP, Sichuan, People's Republic of China
  The inspection and tracking of laser-induced damages of optics play a significant role in high-power laser systems. Laser-induced defects or flaws on the surfaces of optics are presented in images acquired by specific charge coupled devices (CCDs), hence the identification of defects from laser damage images is essential. Despite a great effort we have made to improve the imaging results, the defect identification is a challenging task. The proposed research focuses on the pre-processing of laser damage images, which assists identifying optic defects. We formulate the image pre-processing as a total variation (TV) based image reconstruction problem, and further develop an alternating direction method of multipliers (ADMM) algorithm to solve it. The use of TV regularization makes the pre-processed image sharper by preserving the edges or boundaries more accurately. Experimental results demonstrate the effectiveness of this method.  
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WEBPL02 On-Axis 3D Microscope for X-Ray Beamlines at NSLS-II ion, alignment, detector, EPICS 1048
  • K.J. Gofron, Y.Q. Cai
    BNL, Upton, Long Island, New York, USA
  • J. Wlodek
    Stony Brook University, Computer Science Department, Stony Brook, New York, USA
  Funding: Work supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-SC0012704.
A series of versatile on-axis X-ray microscopes with large working distances, high resolution and large magnification have been developed for in-situ sample alignment and X-ray beam visualization at beam-lines at NSLS-II [1]. The microscopes use reflective optics, which minimizes dispersion, and allows imaging from Ultraviolet (UV) to Infrared (IR) with specifically chosen objective components (coatings, etc.) [2]. Currently over seven reflective microscopes have been procured with several installed at NSLS2 beam-lines. Additional customizations can be implemented providing for example dual-view with high/low magnification, 3-D imaging, long working range, as well as ruby pressure system measurement. The microscope camera control frequently utilizes EPICS areaDetector. In specialized applications python programs integrate EPICS camera control, with computer vision, and EPICS motion control for goniostat centering or object detection applications.
[1] K. J. Gofron, et. al.; AIP Conf. Proc. 1741, 030027-1-030027-4; doi: 10.1063/1.4952850.
[2] K. J. Gofron, et. al., Nucl. Instr. and Meth. A 649, 109 (2011).
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THPHA116 Emittance Measurement and Optics Matching at the European XFEL ion, FEL, emittance, quadrupole 1655
  • S.M. Meykopff, B. Beutner
    DESY, Hamburg, Germany
  Electron beam quality described by the emittance or phase space moments are important for the operation of FEL facilities like the European XFEL. For the operation these parameters need to be routinely measured. Based on such measurements machine setup can be optimized to match beam requirements. The beam parameters depend on parameters like quadrupole magnet strength or RF settings. While manual tuning is possible, we aim for highly automatized procedures to obtain such optimizations. In this paper we will present and discuss an overview of the different subsystems which are involved. These include image acquisition, analysis, and optics calculations as well as machine control user interfaces.  
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