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Lee, S.-Y.

Paper Title Page
WEPCH183 Enhancement of Mechanical Properties of High Chromium Steel by Nitrogen Ion Implantation 2361
 
  • B.S. Kim, S.-Y. Lee
    Hankuk Aviation University, KyungKi-Do
  • K. R. Kim, J.S. Lee
    KAERI, Daejon
  
  This article reports the study of mechanical properties of high chromium steel after N-ion implantation. The samples are implanted with 120keV N-ion at doses ranging from 1x1017ions/square cm to 4x1018ions/square cm. Mechanical properties of implanted samples are compared with those of Cr-plated samples. The compositions of the N-ion implanted layer were measured by Auger electrons spectroscopy(AES). Their mechanical properties as a function of N-ion doses were characterized by nano-indentation, sliding and impact wear tests. The results reveal that the hardness and mechanical properties of ion implanted samples were found to depend strongly on the ion doses. The hardness of the N-ion implanted sample with 2x1018ions/? was measured to be approximately 9 GPa, which is approximately 2.3 times higher than that of un-implanted sample (H=3.8 GPa). Also wear properties of N-ion implanted samples with 2x1018ions/? were largely improved ;compared to the Cr-plated samples, the width of wear track and friction coefficient developed on the N-ion implanted samples are about 60% and 40% smaller, respectively.  
THPCH130 Design and Implementation of Analog Feedback Damper System for an Electron-proton Instability at the Los Alamos Proton Storage Ring 3104
 
  • C. Deibele, S. Assadi, V.V. Danilov, S. Henderson, M.A. Plum, C. Sibley III
    ORNL, Oak Ridge, Tennessee
  • S. Breitzmann, S.-Y. Lee
    IUCF, Bloomington, Indiana
  • J.M. Byrd
    LBNL, Berkeley, California
  • J.D. Gilpatrick, R.J. Macek, R.C. McCrady, J.F. Power, J. Zaugg
    LANL, Los Alamos, New Mexico
  
  The PSR (Proton Storage Ring) at LANSCE has observed an E-P (electron-proton) instability. A wideband analog feedback damper system was designed and implemented that has shown it is possible to correct this instability. The damper system consists of two 180 degree hybrids, low level amplifiers, a delay line, comb filter, power amplifiers, and adjustable delay lines. The system bandwidth is about between 10-300 MHz, and was developed and implemented in stages showing improvement in the e-p threshold of the buncher voltage. The system takes advantage of fiber optic technology for delays as well as for the comb filter. A system description and some measurement results are presented.