Author: Ishibori, I.
Paper Title Page
MOPB75 Real-time Beam Profile Measurement System using Fluorescent Screens 246
 
  • T. Yuyama, I. Ishibori, T. Ishizaka, S. Okumura, Y. Yuri
    JAEA/TARRI, Gunma-ken, Japan
 
  In the TIARA AVF cyclotron facility of JAEA, we are developing an irradiation technique of a large-area uniform ion beam formed by nonlinear focusing using multipole magnets. It is indispensable to perform beam tuning and evaluation of the beam quality at the same time for efficient operation. Therefore, we developed a real-time beam profile measurement system composed of two CCD cameras, fluorescent screens, and an image analysis program based on LabVIEW. In order to measure the transverse intensity distribution of the beam through the luminance map converted from a camera image, the characteristics of fluorescent screens, DRZ (Gd2O2S:Tb) and AF995R (Al2O3:Cr), were investigated using several species of ion beams. It was found that the light yield from the DRZ-HIGH screen irradiated with 10 MeV H+ beam was increased linearly with the particle fluence rate from 5×107 to 5×108 [cm-2・s−1] and that the relative transverse intensity distribution could be obtained from the fluorescence in real time. It was also confirmed that the intensity distribution measured in this system agreed well with the relative intensity distribution obtained with a Gafchromic radiochromic film.  
 
TUPB79 Use of Gafchromic Films to Measure the Transverse Intensity Distribution of a Large-area Ion Beam 531
 
  • Y. Yuri, I. Ishibori, T. Ishizaka, A. Kitamura, S. Okumura, T. Yuyama
    JAEA/TARRI, Gunma-ken, Japan
  • S. Sawada, T. Yamaki
    JAEA/QuBS, Takasaki, Japan
 
  In the TIARA AVF cyclotron facility of JAEA, it is necessary to evaluate the cross-sectional area and uniformity of a large-area uniform ion beam formed by multipole magnets both precisely and handily. A technique has, therefore, been developed to measure the two-dimensional transverse intensity distribution of the ion beam using Gafchromic radiochromic films (Ashland Inc.). In order to show available fluence ranges of the film, the coloring response of the Gafchromic films irradiated with several species of ion beams is investigated as a change in the optical density of the film. It has been found that the optical density increases linearly with the fluence, whose range is practical for materials and biological research. Thus, the relative transverse intensity distribution of ion beams can be measured using the film. Furthermore, the intensity distribution determined by the Gafchromic film is compared with the area-density distribution of track-etched pores in a polymer film from a microscopic viewpoint. It has been demonstrated that the beam uniformity obtained from the Gafchromic film is equivalent to the relative standard deviation of the microscopic pore distribution.