IBIC2012 - List of Authors (Okumura, S.)

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.

TUPB65	Transverse-acceptance Measurement System for the JAEA AVF Cyclotron	499
	H. Kashiwagi, S. Kurashima, N. Miyawaki, S. Okumura JAEA/TARRI, Gunma-ken, Japan
	We are developing an acceptance measurement system to evaluate transverse phase-space matching of the emittance of an injection beam to the acceptance of the AVF cyclotron. The system is composed of a phase-space collimator in the low energy section and a beam intensity monitor in the high energy section. The phase-space collimator, which consists of two pairs of slits, allows very small-emittance beams to be injected into the cyclotron by limiting position and divergence angle of the beam from an ion source. The beam intensity monitor is used to obtain the ratio of beam intensity at the collimator to that at the monitor. In acceptance measurement, the small-emittance beams at various positions in a transverse phase-plane are injected to determine the distribution of relative transmission in the phase plane. In preliminary tests, only a part of acceptance was able to be measured because the injection-beam emittance from ion sources does not cover the whole acceptance. To expand the measurement area, a steering magnet has been added in the system. The magnet scans the injection beam in phase planes in synchronization with the acceptance measurement to simulate the large emittance.

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.

Paper

Title

Page

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.

TUPB65

Transverse-acceptance Measurement System for the JAEA AVF Cyclotron

499

H. Kashiwagi, S. Kurashima, N. Miyawaki, S. Okumura
JAEA/TARRI, Gunma-ken, Japan

We are developing an acceptance measurement system to evaluate transverse phase-space matching of the emittance of an injection beam to the acceptance of the AVF cyclotron. The system is composed of a phase-space collimator in the low energy section and a beam intensity monitor in the high energy section. The phase-space collimator, which consists of two pairs of slits, allows very small-emittance beams to be injected into the cyclotron by limiting position and divergence angle of the beam from an ion source. The beam intensity monitor is used to obtain the ratio of beam intensity at the collimator to that at the monitor. In acceptance measurement, the small-emittance beams at various positions in a transverse phase-plane are injected to determine the distribution of relative transmission in the phase plane. In preliminary tests, only a part of acceptance was able to be measured because the injection-beam emittance from ion sources does not cover the whole acceptance. To expand the measurement area, a steering magnet has been added in the system. The magnet scans the injection beam in phase planes in synchronization with the acceptance measurement to simulate the large emittance.

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.