Author: Mitsuhashi, T.M.
Paper Title Page
WE3AB2
 Simulation and Progress in Ionization Profile Monitors for High Intensty Proton Beam  
 
  • K. Satou, T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  
  Nondestructive beam profile monitoring is strongly requested for the proton machines, especially for the measurement of the high intensity high brightness beams. Ionization profile monitor is traditionally used for measurement of beam profile in the proton machines and proposed to measure the high intensity high brightness beams. The important issues are no uniformities of extraction field, velocity distribution of e- from ionization process, the strong beam field and detection system, etc. In this talk, we will review recent developments on these issues from theoretical and experimental approach.  
slides icon Slides WE3AB2 [3.546 MB]  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPCC09 Horizontal Opening of the Synchrotron Radiation and Effect of Incoherent Depth of Field for Horizontal Beam Size Measurement 364
 
  • T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  • M.J. Boland
    ASCo, Clayton, Victoria, Australia
  • W.J. Corbett
    SLAC, Menlo Park, California, USA
  
  The incoherent depth-of-field due to the instantaneous opening angle of dipole SR emission can influence horizontal beam size measurements. In particular, for double-slit spatial interferometry, the opening angle introduces an intensity imbalance across the two slits that reduces interference contrast and therefore increases the apparent beam size. To investigate this effect, the instantaneous horizontal opening of the SR light must be known. Schwinger's theory gives the vertical opening angle and the qualitative theory of K.J. Kim gives an estimate for horizontal opening angle. An extension of Schwinger's theory to the horizontal plane by one of the authors leads to the same Bessel function distribution as the vertical plane using integration by parts. Neglecting the cubic phase term in the exponent, the expression agrees with Kim's diffraction theory. Using this result to correct for incoherent depth-of-field effects in double-slit measurements at the Australian Synchrotron, ATF and SPEAR3, the measured horizontal beam size is in good agreement with design values.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPCC09  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPCC10 Analysis of Mie Scattering Noise of Objective Lens in Coronagraph for Halo Measurement 369
 
  • T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  
  In beam halo measurements by means of a coronagraph viewing visible SR light, the theoretical image contrast is dominated by leakage of the diffracted fringe pattern from the Lyot stop. On other hand, the noise background in an actual coronagraph also contains light scattered from imperfections in the first objective lens. Most of this light is due to Mie-scattering from dig imperfections on the surface of objective which can reduce the image contrast to the 10-3 range for a lens with 60/40 scratch and dig figures. By introducing a high-quality objective lens into the system the theoretical value of 10-5-10-6 image contrast can be recovered for the Lyot coronagraph. In this paper, Mie-scattering due to dig imperfections is analyzed theoretically and results from measurements of the Mie scattering are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2017-WEPCC10  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)