SAP2023 - List of Keywords (multipole)

Paper	Title	Other Keywords	Page
TUPB008	Evaluation of Field Quality for Elliptical and Curved Magnets	HOM, FFAG, octupole, controls	96
	J. Li, K.D. Wang, X.Q. Yan, K. Zhu PKU, Beijing, People’s Republic of China
	The elliptical magnetic field zone is a useful tool for beam distribution homogenization and FFAG accelerators. Additionally, strongly curved magnets are studied for their application in beam transmission and nuclear fusion. However, traditional magnetic measurements, known as field harmonics, for straight magnets are not suitable for these two kinds of special magnets. In this article, advanced multipoles are used to characterize the fields of straight magnets with elliptical apertures and 2D axisymmetric enclosed curved magnets. The article provides a detailed analysis of magnetic fields using data from FEA or Biot-Savart law. Furthermore, the article discusses methods for characterizing the field quality of unclosed curved magnets used for gantry.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB008
About •	Received ※ 09 July 2023 — Revised ※ 10 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 12 January 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB013	Multipole Field Optimization of X-Band High Gradient Structure	quadrupole, cavity, simulation, acceleration	108
	B.Y. Feng, H.B. Chen, Q. Gao, X. Lin, J.R. Shi, H. Zha TUB, Beijing, People’s Republic of China
	The X-band constant gradient acceleration structure plays a crucial role in the VIGAS project. However, the presence of a multipole field component in the struc-ture’s coupler leads to an increase in ray bandwidth and a decrease in yield, ultimately affecting the quality of the generated rays. Through calculations, it has been determined that the quadrupole field component is particularly prominent in the original structure, ac-counting for 29.5% of the fundamental mode strength. Therefore, it is necessary to modify the cavity struc-ture of the coupler. By altering the shape of the cavity to two staggered circles, the objective of reducing the quadrupole field is achieved. The optimized quadru-pole field component now accounts for approximately 0.3% of the fundamental mode strength. Subsequently, the non-resonant perturbation method was employed to simulate and experimentally measure the magnitude of the multipole field component in the actual acceler-ation cavity.
	Poster TUPB013 [0.350 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB013
About •	Received ※ 30 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 27 September 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

TUPB008

Evaluation of Field Quality for Elliptical and Curved Magnets

HOM, FFAG, octupole, controls

96

J. Li, K.D. Wang, X.Q. Yan, K. Zhu
PKU, Beijing, People’s Republic of China

The elliptical magnetic field zone is a useful tool for beam distribution homogenization and FFAG accelerators. Additionally, strongly curved magnets are studied for their application in beam transmission and nuclear fusion. However, traditional magnetic measurements, known as field harmonics, for straight magnets are not suitable for these two kinds of special magnets. In this article, advanced multipoles are used to characterize the fields of straight magnets with elliptical apertures and 2D axisymmetric enclosed curved magnets. The article provides a detailed analysis of magnetic fields using data from FEA or Biot-Savart law. Furthermore, the article discusses methods for characterizing the field quality of unclosed curved magnets used for gantry.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB008

About •

Received ※ 09 July 2023 — Revised ※ 10 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 12 January 2024

Cite •

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

TUPB013

Multipole Field Optimization of X-Band High Gradient Structure

quadrupole, cavity, simulation, acceleration

108

B.Y. Feng, H.B. Chen, Q. Gao, X. Lin, J.R. Shi, H. Zha
TUB, Beijing, People’s Republic of China

The X-band constant gradient acceleration structure plays a crucial role in the VIGAS project. However, the presence of a multipole field component in the struc-ture’s coupler leads to an increase in ray bandwidth and a decrease in yield, ultimately affecting the quality of the generated rays. Through calculations, it has been determined that the quadrupole field component is particularly prominent in the original structure, ac-counting for 29.5% of the fundamental mode strength. Therefore, it is necessary to modify the cavity struc-ture of the coupler. By altering the shape of the cavity to two staggered circles, the objective of reducing the quadrupole field is achieved. The optimized quadru-pole field component now accounts for approximately 0.3% of the fundamental mode strength. Subsequently, the non-resonant perturbation method was employed to simulate and experimentally measure the magnitude of the multipole field component in the actual acceler-ation cavity.

Poster TUPB013 [0.350 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB013

About •

Received ※ 30 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 27 September 2024

Cite •

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