Author: Oh, B.G.
Paper Title Page
TUPMP032 Design of Analog to Digital Converter Scheme for High - Precision Electromagnet Power supply 1309
 
  • M.J. Kim, Choi. Choi
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • J.H. Han, S.-H. Jeong, Y.G. Jung, H.-S. Kang, D.E. Kim, H.-G. Lee, S.B. Lee, S.J. Lee, B.G. Oh, K.-H. Park, H.S. Suh
    PAL, Pohang, Kyungbuk, Republic of Korea
  • M.S. Kim
    Dongguk University, Seoul, Republic of Korea
  
  This paper deals with the design of an analogue-to-digital converter (ADC) scheme for a highly precise magnet current supply (MPS). The MPSs are requires with stable and precise current specification in range of the ppm. To meet the requirements, the AD circuit is composed of parallel ADCs of low-medium resolution. Digitally, the oversampling and averaging are performed to increase both the effective resolution and the signal to noise ratio (SNR). The implemented AD circuit was improved about 18 dB (32 times oversampling). The MPS applied by the proposed ADC scheme provides more precise control and the stable current within 10 ppm at 200 A. The experiment used a dipole magnet of the PAL-XFEL and its results proved feasibility through precisely measurable DVM3458A (Keysight Co.).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP032  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPGW089 Mechanical Design of a Diamond Crystal Hard X-Ray Self-Seeding Monochromator for PAL-XFEL 3782
 
  • D. Shu, J.W.J. Anton, S.P. Kearney, K. Kim, Yu. Shvyd’ko
    ANL, Argonne, Illinois, USA
  • H.-S. Kang, C.-K. Min, B.G. Oh, S.Y. Rah
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357
As a part of the Argonne Strategic Partnership Project (SPP) 85H21, a collaboration between Advanced Photon Source (APS), Argonne National Laboratory (ANL) and Pohang Accelerator Laboratory (PAL), we have designed, constructed, and tested a thin-film-diamond monochromator for the PAL X-ray Free-Electron-Laser (PAL-XFEL) hard x-ray self-seeding project*. The mechanical design of the PAL-XFEL diamond crystal hard x-ray self-seeding monochromator is based on the APS design of a diamond-crystal monochromator for the LCLS hard x-ray self-seeding project** with enhanced diamond crystal holder for two thin-film-diamond crystals with thicknesses of 30 microns and 100 microns***. The customized high quality thin-film-diamonds and special graphite holder were provided by the Technological Institute for Super-hard and Novel Carbon Materials of Russia (TISNCM)****, and tested at the APS***. An in-vacuum multi-axis precision positioning mechanism is designed to manipulate the duo-thin-film diamonds holder with resolutions and stabilities required by the hard x-ray self-seeding physics. Mechanical specifications, designs, and preliminary test results of the diamond monochromator are presented in this paper.
*Chang-Ki Min, et al, sub. J. Sync. Rad., 2018
**D. Shu, et al, J. Phys.: Conf. Ser. 425 (2013) 052004
***Y. Shvyd’ko, et al, FEL2017, Santa Fe
****Polyakov S, et. al, 2011 Diam. Rel. Mat. 20 726 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW089  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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