PAC2013 - List of Authors (Yuri, Y.)

Paper

Title

Page

Possible Observation of Transverse Laser Cooled Ultimate Cold Ion Beam in S-LSR*

886

K. Jimbo
Kyoto University, Kyoto, Japan
M. Nakao, A. Noda, T. Shirai
NIRS, Chiba-shi, Japan
H. Souda
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

Transverse laser cooling is pursued at an ion storage/cooler ring, S-LSR, Kyoto University. An RF bunched Mg+ beam was cooled transversely through synchro-betatron resonance coupling by a co-propagating laser. We investigated peaks of the synchrotron oscillation spectroscopically so that we can observe it stably. Oscillation signals from a parallel-plate pickup were observed by a spectrum analyzer. We also observed the coherent synchrotron modes. As the beam temperature decreases, the ion beam would be in space charge limited region. According to the computer simulation, in the case the beam turns to be space charge limited, the disappearance of peaks of the synchrotron oscillation is expected. We would like to propose a capability of detecting space charge limited region by observation of such a frozen synchrotron oscillation.

THPHO01

Parameter Optimization for Multi-Dimensional Laser Cooling for an Ion Beam in the Storage Ring S-LSR

1298

Z.Q. He
TUB, Beijing, People's Republic of China
K. Jimbo
Kyoto University, Kyoto, Japan
M. Nakao, A. Noda
NIRS, Chiba-shi, Japan
H. Okamoto, K. Osaki
HU/AdSM, Higashi-Hiroshima, Japan
H. Souda
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
J. Wei
FRIB, East Lansing, USA
Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

Funding: Advanced Compact Accelerator Development project, MEXT, Japan. GCOE project, Kyoto University, Japan.
Abstract: S-LSR is a compact ion cooler ring built in ICR, Kyoto University, aiming at creating ultra-low temperature ion beam by laser cooling. In order to approach lowest possible temperature at S-LSR in an experiment, parameters of laser cooling should be carefully chosen by simulation. This paper mainly concerns on optimization of laser cooling parameters and prediction of possible low limit of beam temperature at S-LSR. Firstly, the adiabatic capture process of ion beam is introduced and studied. Then, different laser profile parameters are compared and an optimized value is chosen. After that, optimized solenoid field strength for 3-D coupling is proposed. At last, by choosing the parameters proposed, the lowest beam temperature achievable for S-LSR is predicted to be 10K in horizontal direction and 0.05K in longitudinal direction.

THPSM01

Ion-irradiation Response of Gafchromic Films and their Application to the Measurement of the Transverse Beam Intensity Distribution

1388

Y. Yuri, I. Ishibori, T. Ishizaka, S. Okumura, T. Yuyama
JAEA/TARRI, Gunma-ken, Japan

The response of radiochromic films, Gafchromic HD-810 and EBT2, was investigated using MeV-class proton and heavy-ion beams to apply the films to a measurement technique of the transverse beam intensity distribution at an azimuthally-varying-field cyclotron of Japan Atomic Energy Agency. The optical density of the films was increased linearly with the particle fluence of the beam in a low-fluence region. The linear-response range of the fluence was strongly dependent on ion species as well as on the film type. By analyzing the film response to absorbed dose with linear energy transfer, it was found that the sensitivity of the film was decreased for heavy-ion beams. An approximate formula was given for the practical fluence range of the Gafchromic film HD-810 on an arbitrary ion beam. The present technique with the use of the two types of Gafchromic films enables us to measure the intensity distribution of a large-area ion beam handily in a wide fluence range. Using the technique, we measured the relative intensity distribution of a large-area ion beam focused with multipole magnets and evaluated its size and uniformity.

FROAA4

Simulation Study on Transverse Laser Cooling and Ordering of Heavy-Ion Beams in a Storage Ring

1434

Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

Molecular dynamics approach in which stochastic interaction between laser photons and ions is incorporated is employed to study the formation of three-dimensionally ultralow-temperature coasting beams by means of laser cooling in a storage ring. The effect of momentum dispersion on the laser-cooling process is investigated for efficient transverse cooling through tapered cooling and resonant coupling. The indirect transverse cooling force is dependent on the displacement of the laser axis and laser detuning as well as on dispersion. A string-like crystalline state of the beam can be attained at low line density by means of three-dimensional (3D) cooling. On the other hand, 3D ordered structures can be formed at higher line density by adjusting the tapered laser-cooling force. The characteristics of Coulomb-ordered beams are discussed.

Slides FROAA4 [1.571 MB]

Paper	Title	Page
WEPBA02	Possible Observation of Transverse Laser Cooled Ultimate Cold Ion Beam in S-LSR*	886
	K. Jimbo Kyoto University, Kyoto, Japan M. Nakao, A. Noda, T. Shirai NIRS, Chiba-shi, Japan H. Souda Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan H. Tongu Kyoto ICR, Uji, Kyoto, Japan Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	Transverse laser cooling is pursued at an ion storage/cooler ring, S-LSR, Kyoto University. An RF bunched Mg+ beam was cooled transversely through synchro-betatron resonance coupling by a co-propagating laser. We investigated peaks of the synchrotron oscillation spectroscopically so that we can observe it stably. Oscillation signals from a parallel-plate pickup were observed by a spectrum analyzer. We also observed the coherent synchrotron modes. As the beam temperature decreases, the ion beam would be in space charge limited region. According to the computer simulation, in the case the beam turns to be space charge limited, the disappearance of peaks of the synchrotron oscillation is expected. We would like to propose a capability of detecting space charge limited region by observation of such a frozen synchrotron oscillation.

THPHO01	Parameter Optimization for Multi-Dimensional Laser Cooling for an Ion Beam in the Storage Ring S-LSR	1298
	Z.Q. He TUB, Beijing, People's Republic of China K. Jimbo Kyoto University, Kyoto, Japan M. Nakao, A. Noda NIRS, Chiba-shi, Japan H. Okamoto, K. Osaki HU/AdSM, Higashi-Hiroshima, Japan H. Souda Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan J. Wei FRIB, East Lansing, USA Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	Funding: Advanced Compact Accelerator Development project, MEXT, Japan. GCOE project, Kyoto University, Japan. Abstract: S-LSR is a compact ion cooler ring built in ICR, Kyoto University, aiming at creating ultra-low temperature ion beam by laser cooling. In order to approach lowest possible temperature at S-LSR in an experiment, parameters of laser cooling should be carefully chosen by simulation. This paper mainly concerns on optimization of laser cooling parameters and prediction of possible low limit of beam temperature at S-LSR. Firstly, the adiabatic capture process of ion beam is introduced and studied. Then, different laser profile parameters are compared and an optimized value is chosen. After that, optimized solenoid field strength for 3-D coupling is proposed. At last, by choosing the parameters proposed, the lowest beam temperature achievable for S-LSR is predicted to be 10K in horizontal direction and 0.05K in longitudinal direction.

THPSM01	Ion-irradiation Response of Gafchromic Films and their Application to the Measurement of the Transverse Beam Intensity Distribution	1388
	Y. Yuri, I. Ishibori, T. Ishizaka, S. Okumura, T. Yuyama JAEA/TARRI, Gunma-ken, Japan
	The response of radiochromic films, Gafchromic HD-810 and EBT2, was investigated using MeV-class proton and heavy-ion beams to apply the films to a measurement technique of the transverse beam intensity distribution at an azimuthally-varying-field cyclotron of Japan Atomic Energy Agency. The optical density of the films was increased linearly with the particle fluence of the beam in a low-fluence region. The linear-response range of the fluence was strongly dependent on ion species as well as on the film type. By analyzing the film response to absorbed dose with linear energy transfer, it was found that the sensitivity of the film was decreased for heavy-ion beams. An approximate formula was given for the practical fluence range of the Gafchromic film HD-810 on an arbitrary ion beam. The present technique with the use of the two types of Gafchromic films enables us to measure the intensity distribution of a large-area ion beam handily in a wide fluence range. Using the technique, we measured the relative intensity distribution of a large-area ion beam focused with multipole magnets and evaluated its size and uniformity.

FROAA4	Simulation Study on Transverse Laser Cooling and Ordering of Heavy-Ion Beams in a Storage Ring	1434
	Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	Molecular dynamics approach in which stochastic interaction between laser photons and ions is incorporated is employed to study the formation of three-dimensionally ultralow-temperature coasting beams by means of laser cooling in a storage ring. The effect of momentum dispersion on the laser-cooling process is investigated for efficient transverse cooling through tapered cooling and resonant coupling. The indirect transverse cooling force is dependent on the displacement of the laser axis and laser detuning as well as on dispersion. A string-like crystalline state of the beam can be attained at low line density by means of three-dimensional (3D) cooling. On the other hand, 3D ordered structures can be formed at higher line density by adjusting the tapered laser-cooling force. The characteristics of Coulomb-ordered beams are discussed.
	Slides FROAA4 [1.571 MB]