SAP2023 - List of Keywords (focusing)

Paper	Title	Other Keywords	Page
MOIBA01	Research on Beam Dynamics of a 2 GeV 6 MW Isochronous FFA	resonance, extraction, cyclotron, space-charge	4
	T.J. Zhang, T.J. Bian, Z.C. Chu, W. Fu, H. Le, J.Y. Liu, S. Pei, C. Wang, Z.G. Yin, S.P. Zhang, H. Zhou, X.F. Zhu CIAE, Beijing, People’s Republic of China Z.Y. Yin FRIB, East Lansing, Michigan, USA
	Funding: This work was supported in part by the National Natural Science Foun-dation of China under Grant 12135020. CIAE has proposed an innovative design for a 2 GeV/6 MW isochronous FFA in 2019. This study aims to present the results of beam dynamics research, demonstrating the feasibility to accelerate the intense proton beam with the energy beyond 1 GeV limitation of isochronous cyclotrons. By introducing 1st - 3rd radial gradient of peak magnetic field to simulate the quadrupole to octupole component of the isochronous machine, three different lattice designs are obtained. Adjusting the radial gradient of the peak field allows an option to avoid or cross integer resonances. Various inherent and coupled resonances are investigated subsequently, with a focus on the destructive effects of the Vr=3 on the transverse phase space. Based on PIC method, we simulate the vortex motion caused by space charge in a large-scale alternating gradient field. Results indicated that the radial size of beam is ~ 10 mm, which is expected to be improved after considering the effects of neighboring bunches. Additionally, high-Q RF cavities and precession extraction further enlarge the turn separation to 30 mm, ensuring efficient beam extraction in the extraction region.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOIBA01
About •	Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 02 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB005	Design of Beam Dynamics for a High-Power DC Proton Accelerator at the MeV Level	space-charge, proton, acceleration, neutron	24
	Z.-F. He, M.H. Zhao SINAP, Shanghai, People’s Republic of China W. Wan ShanghaiTech University, Shanghai, People’s Republic of China
	This paper aims to design the beam dynamics of a MeV-level high-power DC proton accelerator for use in high-voltage accelerators. The high-power proton accelerator has essential applications such as ion implantation equipment, neutron therapy equipment, and accelerator-based neutron source equipment. With the increasing use of high-voltage generators due to their stable and reliable operation, these accelerators have gained significant popularity in the field. The paper discusses the design considerations of the accelerator equipment, including the functions and requirements of the acceleration tube, electric field distribution, and voltage holding issues. Additionally, the paper focuses on the design aspects of beam optics, encompassing topics such as electric field distribution, beam focusing, beam transmission, divergence, and the impact of space charge effects on beam quality. Calculations and optimizations are performed based on the parameters and requirements specific to high-voltage accelerators. Finally, the paper presents and analyzes the results of the accelerator tube and beam optics design.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB005
About •	Received ※ 30 June 2023 — Revised ※ 09 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 04 October 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB019	Beam Dynamics in Superconducting Proton Linac	quadrupole, simulation, acceleration, resonance	126
	X.M. Wan, Z. Li, W.L. Liao, P.T. Lin, X.B. Luo, X.J. Pu, Z.Q. Ren, Y.F. Yang SCU, Chengdu, People’s Republic of China
	Funding: This work was supported by the National Natural Science Foundation of China (Grant Nos. 11375122 and 11875197). Beam loss control is a crucial research direction in high-current superconducting linear accelerators (SCL). The research findings include firstly, for continuous beams, when tune depression eta > 0.7, zero current periodic phase advance (σ0t) can partially exceed 90° during transport in solenoid and quadrupole doublet periodic focusing channels. Different results occur when eta < 0.7. Secondly, in the solenoid system, σ0t can partially exceed 90° without significant impact on beam quality. In the quadrupole doublet focusing system, the partial breakdown of 90° affects beam quality. Thirdly, Similar conclusions hold for acceleration effects. Fourthly, numerical analysis shows that double-period structures have more stringent design criteria than fully period structures. The double-period structure can cause envelope instability even if σ0t < 90°. Fifthly, the primary factor causing halo is the 2:1 resonance. Additionally, when eta is small, higher-order resonances can also cause halo.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB019
About •	Received ※ 09 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 08 April 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOIBA01

Research on Beam Dynamics of a 2 GeV 6 MW Isochronous FFA

resonance, extraction, cyclotron, space-charge

4

T.J. Zhang, T.J. Bian, Z.C. Chu, W. Fu, H. Le, J.Y. Liu, S. Pei, C. Wang, Z.G. Yin, S.P. Zhang, H. Zhou, X.F. Zhu
CIAE, Beijing, People’s Republic of China
Z.Y. Yin
FRIB, East Lansing, Michigan, USA

Funding: This work was supported in part by the National Natural Science Foun-dation of China under Grant 12135020.
CIAE has proposed an innovative design for a 2 GeV/6 MW isochronous FFA in 2019. This study aims to present the results of beam dynamics research, demonstrating the feasibility to accelerate the intense proton beam with the energy beyond 1 GeV limitation of isochronous cyclotrons. By introducing 1st - 3rd radial gradient of peak magnetic field to simulate the quadrupole to octupole component of the isochronous machine, three different lattice designs are obtained. Adjusting the radial gradient of the peak field allows an option to avoid or cross integer resonances. Various inherent and coupled resonances are investigated subsequently, with a focus on the destructive effects of the Vr=3 on the transverse phase space. Based on PIC method, we simulate the vortex motion caused by space charge in a large-scale alternating gradient field. Results indicated that the radial size of beam is ~ 10 mm, which is expected to be improved after considering the effects of neighboring bunches. Additionally, high-Q RF cavities and precession extraction further enlarge the turn separation to 30 mm, ensuring efficient beam extraction in the extraction region.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOIBA01

About •

Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 02 October 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB005

Design of Beam Dynamics for a High-Power DC Proton Accelerator at the MeV Level

space-charge, proton, acceleration, neutron

24

Z.-F. He, M.H. Zhao
SINAP, Shanghai, People’s Republic of China
W. Wan
ShanghaiTech University, Shanghai, People’s Republic of China

This paper aims to design the beam dynamics of a MeV-level high-power DC proton accelerator for use in high-voltage accelerators. The high-power proton accelerator has essential applications such as ion implantation equipment, neutron therapy equipment, and accelerator-based neutron source equipment. With the increasing use of high-voltage generators due to their stable and reliable operation, these accelerators have gained significant popularity in the field. The paper discusses the design considerations of the accelerator equipment, including the functions and requirements of the acceleration tube, electric field distribution, and voltage holding issues. Additionally, the paper focuses on the design aspects of beam optics, encompassing topics such as electric field distribution, beam focusing, beam transmission, divergence, and the impact of space charge effects on beam quality. Calculations and optimizations are performed based on the parameters and requirements specific to high-voltage accelerators. Finally, the paper presents and analyzes the results of the accelerator tube and beam optics design.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB005

About •

Received ※ 30 June 2023 — Revised ※ 09 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 04 October 2024

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB019

Beam Dynamics in Superconducting Proton Linac

quadrupole, simulation, acceleration, resonance

126

X.M. Wan, Z. Li, W.L. Liao, P.T. Lin, X.B. Luo, X.J. Pu, Z.Q. Ren, Y.F. Yang
SCU, Chengdu, People’s Republic of China

Funding: This work was supported by the National Natural Science Foundation of China (Grant Nos. 11375122 and 11875197).
Beam loss control is a crucial research direction in high-current superconducting linear accelerators (SCL). The research findings include firstly, for continuous beams, when tune depression eta > 0.7, zero current periodic phase advance (σ0t) can partially exceed 90° during transport in solenoid and quadrupole doublet periodic focusing channels. Different results occur when eta < 0.7. Secondly, in the solenoid system, σ0t can partially exceed 90° without significant impact on beam quality. In the quadrupole doublet focusing system, the partial breakdown of 90° affects beam quality. Thirdly, Similar conclusions hold for acceleration effects. Fourthly, numerical analysis shows that double-period structures have more stringent design criteria than fully period structures. The double-period structure can cause envelope instability even if σ0t < 90°. Fifthly, the primary factor causing halo is the 2:1 resonance. Additionally, when eta is small, higher-order resonances can also cause halo.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB019

About •

Received ※ 09 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 08 April 2024

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)