Author: Sakemi, Y.
Paper Title Page
TUPP022 Development of the Calculation Method of Injection Beam Trajectory of RIKEN AVF Cyclotron with 4D Emittance Measured by the Developed Pepper-Pot Emittance Monitor 346
 
  • Y. Kotaka, N. Imai, Y. Ohshiro, Y. Sakemi, S. Shimoura, H. Yamaguchi
    CNS, Saitama, Japan
  • A. Goto, M. Kase, T. Nagatomo, T. Nakagawa, J. Ohnishi
    RIKEN Nishina Center, Wako, Japan
  • K. Hatanaka
    RCNP, Osaka, Japan
  • H. Muto
    Suwa University of Science, Chino, Nagano, Japan
 
  The Center for Nuclear Study, the University of Tokyo and RIKEN Nishina Center have been developing the AVF Cyclotron system at RIKEN. One of the important developments is to improve the transport system of the injection beam line. The transport efficiencies tend to decrease as beam intensities increase. To solve this problem, we developed the calculation method to trace a beam trajectory with a four-dimensional (4D) beam emittance measured by pepper-pot emittance monitor (PEM) as initial value. The reason for using the 4D beam emittance is that the transport system has rotating quadrupole magnets and solenoid coils, and that the space charge effect can be introduced. The beams through a pepper-pot mask can be detected on the potassium bromide fluorescent plate inclined 45 degree to the beam to be recorded by digital camera using developed PEM. We compared the calculated beam trajectory with the measurement of other beam diagnostics and quantified the degree of fit. It has been found that the degree of fit is improved by changing fiducial points on the fluorescent plate and optimizing the thickness of the fluorescent agent and the exposure time and gain of the digital camera.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP022  
About • paper received ※ 04 September 2019       paper accepted ※ 10 September 2019       issue date ※ 10 November 2019  
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TUPP023 Two-dimensional Beam Profile Monitor for Alpha Emitter 350
 
  • K.S. Tanaka, K. Harada, M. Itoh, H. Kawamura, A. Terakawa, A. Uchiyama
    CYRIC, Sendai, Japan
  • T. Hayamizu, H. Nagahama, N. Ozawa, Y. Sakemi
    CNS, Saitama, Japan
 
  We developed two-dimensional beam profile monitors for alpha-emitters along with other larger number of ions to measure the permanent electric dipole moment of the electron using francium atoms at CYRIC in Tohoku university. Francium is produced by the fusion reaction between the oxygen beam from the cyclotron accelerator and gold target, and a far larger number of other ions such as fold or potassium are also emitted from the target. Thus it was difficult to measure the beam profile of francium hidden by these ions. We installed two beam profile monitor consisted of the micro-channel plate and phosphor screen. If we stop the beam after the beam injection to the monitor in sufficient time, we can only observe the fluorescence of the alpha particle emitted by francium atoms on the surface of the plates. By using this monitoring system, we improved the beam transport efficiency by several times and improved beam purity of francium with Wien filter.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP023  
About • paper received ※ 04 September 2019       paper accepted ※ 07 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)