PAC2013 - List of Authors (He, Z.Q.)

Paper	Title	Page
TUPAC14	A Linear Envelope Model for Multi-Charge State Linac	478
	Z.Q. He, Z. Liu, J. Wei, Y. Zhang FRIB, East Lansing, USA R.M. Talman Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: U.S. Department of Energy The traditional linear envelope tracking model is widely used in linac design and on-line tuning. However, for multi-charge state acceleration situation, where the transfer matrix is different between charge-states, the linear envelope tracking model cannot be utilized. A direct way to handle multi-charge state acceleration is using multi-particle tracking, which is usually high in precision, but lack in efficiency, therefore is not suitable for linac on-line beam tuning. In this paper, a new approach of adapting linear envelope tracking model onto multi-charge state acceleration situation is proposed. The lattice of FRIB is used to test the scheme in both linac segment and folding segment. And the result is then benchmarked with a multi-particle tracking program IMPACT to ensure its precision with enhancement in efficiency.

WEPAC03	Electro-Magnetic Optimization and Analysis of a Quarter Wave Resonator	790
	Z. Zheng, Z.Q. He TUB, Beijing, People's Republic of China A. Facco INFN/LNL, Legnaro (PD), Italy A. Facco, Z.Q. He, Z. Liu, J. Wei, Y. Xu, Y. Zhang, Z. Zheng FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 A β=0.085 quarter wave resonator (QWR) with resonant frequency=80.5 MHz is used in the Facility of Rare Isotope Beam (FRIB). Its baseline structure is designed to achieve the FRIB specifications with optimum cost to performance ratio. Electro-magnetic optimization is introduced in this paper to modify its internal geometry to reach instead maximum accelerating gradient, while preserving the original flange to flange length. Reduced peak magnetic field and increased shunt impedance are well achieved in the optimization while keeping the same stored energy. The maximum accelerating voltage is raised accordingly. Multipacting and steering are also analyzed for the optimized cavity. This resonator could be used in the ReA linac at MSU and in all applications where the maximum accelerating voltage should be achieved in a limited space, or where the accelerator cost is mainly driven by the resonator gradient.

WEPAC03	Electro-Magnetic Optimization and Analysis of a Quarter Wave Resonator	790
	Z. Zheng, Z.Q. He TUB, Beijing, People's Republic of China A. Facco INFN/LNL, Legnaro (PD), Italy A. Facco, Z.Q. He, Z. Liu, J. Wei, Y. Xu, Y. Zhang, Z. Zheng FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 A β=0.085 quarter wave resonator (QWR) with resonant frequency=80.5 MHz is used in the Facility of Rare Isotope Beam (FRIB). Its baseline structure is designed to achieve the FRIB specifications with optimum cost to performance ratio. Electro-magnetic optimization is introduced in this paper to modify its internal geometry to reach instead maximum accelerating gradient, while preserving the original flange to flange length. Reduced peak magnetic field and increased shunt impedance are well achieved in the optimization while keeping the same stored energy. The maximum accelerating voltage is raised accordingly. Multipacting and steering are also analyzed for the optimized cavity. This resonator could be used in the ReA linac at MSU and in all applications where the maximum accelerating voltage should be achieved in a limited space, or where the accelerator cost is mainly driven by the resonator gradient.

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.

Paper

Title

Page

A Linear Envelope Model for Multi-Charge State Linac

478

Z.Q. He, Z. Liu, J. Wei, Y. Zhang
FRIB, East Lansing, USA
R.M. Talman
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: U.S. Department of Energy
The traditional linear envelope tracking model is widely used in linac design and on-line tuning. However, for multi-charge state acceleration situation, where the transfer matrix is different between charge-states, the linear envelope tracking model cannot be utilized. A direct way to handle multi-charge state acceleration is using multi-particle tracking, which is usually high in precision, but lack in efficiency, therefore is not suitable for linac on-line beam tuning. In this paper, a new approach of adapting linear envelope tracking model onto multi-charge state acceleration situation is proposed. The lattice of FRIB is used to test the scheme in both linac segment and folding segment. And the result is then benchmarked with a multi-particle tracking program IMPACT to ensure its precision with enhancement in efficiency.

WEPAC03

Electro-Magnetic Optimization and Analysis of a Quarter Wave Resonator

790

Z. Zheng, Z.Q. He
TUB, Beijing, People's Republic of China
A. Facco
INFN/LNL, Legnaro (PD), Italy
A. Facco, Z.Q. He, Z. Liu, J. Wei, Y. Xu, Y. Zhang, Z. Zheng
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
A β=0.085 quarter wave resonator (QWR) with resonant frequency=80.5 MHz is used in the Facility of Rare Isotope Beam (FRIB). Its baseline structure is designed to achieve the FRIB specifications with optimum cost to performance ratio. Electro-magnetic optimization is introduced in this paper to modify its internal geometry to reach instead maximum accelerating gradient, while preserving the original flange to flange length. Reduced peak magnetic field and increased shunt impedance are well achieved in the optimization while keeping the same stored energy. The maximum accelerating voltage is raised accordingly. Multipacting and steering are also analyzed for the optimized cavity. This resonator could be used in the ReA linac at MSU and in all applications where the maximum accelerating voltage should be achieved in a limited space, or where the accelerator cost is mainly driven by the resonator gradient.

WEPAC03

Electro-Magnetic Optimization and Analysis of a Quarter Wave Resonator

790

Z. Zheng, Z.Q. He
TUB, Beijing, People's Republic of China
A. Facco
INFN/LNL, Legnaro (PD), Italy
A. Facco, Z.Q. He, Z. Liu, J. Wei, Y. Xu, Y. Zhang, Z. Zheng
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
A β=0.085 quarter wave resonator (QWR) with resonant frequency=80.5 MHz is used in the Facility of Rare Isotope Beam (FRIB). Its baseline structure is designed to achieve the FRIB specifications with optimum cost to performance ratio. Electro-magnetic optimization is introduced in this paper to modify its internal geometry to reach instead maximum accelerating gradient, while preserving the original flange to flange length. Reduced peak magnetic field and increased shunt impedance are well achieved in the optimization while keeping the same stored energy. The maximum accelerating voltage is raised accordingly. Multipacting and steering are also analyzed for the optimized cavity. This resonator could be used in the ReA linac at MSU and in all applications where the maximum accelerating voltage should be achieved in a limited space, or where the accelerator cost is mainly driven by the resonator gradient.

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.