SAP2023 - List of Keywords (space-charge)

Paper	Title	Other Keywords	Page
MOIBA01	Research on Beam Dynamics of a 2 GeV 6 MW Isochronous FFA	resonance, extraction, focusing, cyclotron	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)

MOPB004	Lowest Longitudinal and Transverse Resistive-wall Wake and Impedance for Nonultra-relativistic Beams	wakefield, dipole, impedance, electron	21
	J.Z. Tang TUB, Beijing, People’s Republic of China
	With the development of the steady-state microbunch(SSMB) storage ring, its parameters reveal that the ultra-relativistic assumption which is wildly used is not valid for the electron beam bunch train. For a bunch train with a length in the 100nm range, spacing of 1um, and energy in the hundred MeV range, the action angle of the space charge force is estimated by {r/γ}. The space charge effect of the mirror current loop formed in the wall with a scale of 1cm will have a sustained effect on approximately dozens of microbunches behind the source particle. The strength of the interaction between such bunches and the potential instability it may cause needs careful evaluation. At the same time, the effect of the space charge inside a single bunch due to space charge effect also needs to be considered. We reorganized the lowest-order longitudinal wakefield under non-extreme relativistic conditions, and modified the inconsistent part in the theoretical derivation in some essays of the lowest-order transverse wakefield. We present the modified theoretical results and analysis. The action area are then divided into three parts. It lays foundation in future research.
	Poster MOPB004 [1.278 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB004
About •	Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 22 November 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	focusing, 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)

MOPB008	Approximation of Space Charge Effect in the Presence of Longitudinal Magnetic Fields	simulation, controls, electron, emittance	27
	H.Y. Li, H.B. Chen, Q. Gao, W.H. Gu, J.R. Shi, H. Zha TUB, Beijing, People’s Republic of China
	The space charge effect plays a significant role in the evolution of phase space during beam transport. Applying an external longitudinal magnetic field has been shown to effectively reduce beam expansion through the mechanism of beam rotation. In this article, we present a fast approximation algorithm for estimating the impact of an external magnetic field on beam expansion. The algorithm enables efficient computations and provides insights into controlling the phase space dynamics of the beam in the presence of longitudinal magnetic fields.
	Poster MOPB008 [0.447 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB008
About •	Received ※ 30 June 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 30 April 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB006	Study on XiPAF Synchrotron Nonlinear Dynamics	resonance, synchrotron, injection, simulation	92
	X.Y. Liu, P.Z. Fang, Y. Li, X.W. Wang, Z.J. Wang, Y. Xiong, H.J. Yao, S.X. Zheng TUB, Beijing, People’s Republic of China Z.M. Wang NINT, Shannxi, People’s Republic of China
	Funding: Work supported by National Natural Science Foundation of China (No.12075131) Xi’an Proton Application Facility (XiPAF) has been operational since 2020, which can accumulate 2e11 protons after injection and 1e11 protons after acceleration. In this paper, we have investigated the XiPAF synchrotron nonlinearity by simulation and experiments, the beam loss occurs with resonance vx+2vy=5 in the absence of space charge, and resonance 2vx-2vy=0 in the presence of space charge. The stripping foil also plays an important role due to its multiple scattering effect and ionization energy loss effect.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB006
About •	Received ※ 29 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 04 December 2023
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, focusing, cyclotron

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)

MOPB004

Lowest Longitudinal and Transverse Resistive-wall Wake and Impedance for Nonultra-relativistic Beams

wakefield, dipole, impedance, electron

21

J.Z. Tang
TUB, Beijing, People’s Republic of China

With the development of the steady-state microbunch(SSMB) storage ring, its parameters reveal that the ultra-relativistic assumption which is wildly used is not valid for the electron beam bunch train. For a bunch train with a length in the 100nm range, spacing of 1um, and energy in the hundred MeV range, the action angle of the space charge force is estimated by {r/γ}. The space charge effect of the mirror current loop formed in the wall with a scale of 1cm will have a sustained effect on approximately dozens of microbunches behind the source particle. The strength of the interaction between such bunches and the potential instability it may cause needs careful evaluation. At the same time, the effect of the space charge inside a single bunch due to space charge effect also needs to be considered. We reorganized the lowest-order longitudinal wakefield under non-extreme relativistic conditions, and modified the inconsistent part in the theoretical derivation in some essays of the lowest-order transverse wakefield. We present the modified theoretical results and analysis. The action area are then divided into three parts. It lays foundation in future research.

Poster MOPB004 [1.278 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB004

About •

Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 22 November 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

focusing, 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)

MOPB008

Approximation of Space Charge Effect in the Presence of Longitudinal Magnetic Fields

simulation, controls, electron, emittance

27

H.Y. Li, H.B. Chen, Q. Gao, W.H. Gu, J.R. Shi, H. Zha
TUB, Beijing, People’s Republic of China

The space charge effect plays a significant role in the evolution of phase space during beam transport. Applying an external longitudinal magnetic field has been shown to effectively reduce beam expansion through the mechanism of beam rotation. In this article, we present a fast approximation algorithm for estimating the impact of an external magnetic field on beam expansion. The algorithm enables efficient computations and provides insights into controlling the phase space dynamics of the beam in the presence of longitudinal magnetic fields.

Poster MOPB008 [0.447 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB008

About •

Received ※ 30 June 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 30 April 2024

Cite •

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

TUPB006

Study on XiPAF Synchrotron Nonlinear Dynamics

resonance, synchrotron, injection, simulation

92

X.Y. Liu, P.Z. Fang, Y. Li, X.W. Wang, Z.J. Wang, Y. Xiong, H.J. Yao, S.X. Zheng
TUB, Beijing, People’s Republic of China
Z.M. Wang
NINT, Shannxi, People’s Republic of China

Funding: Work supported by National Natural Science Foundation of China (No.12075131)
Xi’an Proton Application Facility (XiPAF) has been operational since 2020, which can accumulate 2e11 protons after injection and 1e11 protons after acceleration. In this paper, we have investigated the XiPAF synchrotron nonlinearity by simulation and experiments, the beam loss occurs with resonance vx+2vy=5 in the absence of space charge, and resonance 2vx-2vy=0 in the presence of space charge. The stripping foil also plays an important role due to its multiple scattering effect and ionization energy loss effect.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB006

About •

Received ※ 29 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 04 December 2023

Cite •

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