SAP2023 - List of Keywords (controls)

Paper	Title	Other Keywords	Page
MOPB003	Study on a Polarization Controllable Undulator for High-Gain Free Electron Lasers	polarization, undulator, HOM, radiation	18
	R. Huang, Q.K. Jia USTC/NSRL, Hefei, Anhui, People’s Republic of China L.J. Chen CAEP/IAE, Mianyang, Sichuan, People’s Republic of China
	Funding: Work is supported by National Natural Science Foundation of China (12175224, 11805200) SASE FEL can generate intense and coherent linearly-polarized X-ray when high energy electron beams travelling through a long planar undulator. It is also of great importance and interest to control the polarization of FEL. One possible solution is utilizing a customized undulator to adjust the magnetic field direction. By tuning the displacement of the magnetic block arrangement, variation of polarization could be achieved. In this paper we study on a polarization controllable undulator to realize the variable polarized magnetic field. Different shapes and design considerations of the magnetic block configuration will be introduced. The value of peak field and the region of good field will be analysed and discussed.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB003
About •	Received ※ 01 July 2023 — Revised ※ 08 July 2023 — Accepted ※ 09 July 2023 — Issued ※ 20 July 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	space-charge, simulation, 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)

MOPB017	Analysis of the Fluctuation of Resonance Driving Terms for Nonlinear Lattice Optimization	sextupole, storage-ring, resonance, lattice	41
	B.F. Wei, Z.H. Bai, G.Y. Feng, J.J. Tan USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Minimizing resonance driving terms (RDTs) of nonlinear magnets is a traditional approach to enlarge the dynamic aperture (DA) of a storage ring. The local cancellation of nonlinear dynamics, which is adopted by some diffraction-limited storage rings, is more effective than the global cancellation. The former has smaller fluctuation of RDTs along the ring. In this paper, the correlation between two kinds of RDT fluctuations is found. The qualitative analysis shows that minimizing the RDT fluctuations is beneficial for controlling the crossing terms and thus enlarging the DA. This qualitative analysis is supported by the statistical analysis of nonlinear solutions of a double-bend achromat lattice.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB017
About •	Received ※ 10 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 11 April 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB008	Evaluation of Field Quality for Elliptical and Curved Magnets	multipole, HOM, FFAG, octupole	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)

Paper

Title

Other Keywords

Page

MOPB003

Study on a Polarization Controllable Undulator for High-Gain Free Electron Lasers

polarization, undulator, HOM, radiation

18

R. Huang, Q.K. Jia
USTC/NSRL, Hefei, Anhui, People’s Republic of China
L.J. Chen
CAEP/IAE, Mianyang, Sichuan, People’s Republic of China

Funding: Work is supported by National Natural Science Foundation of China (12175224, 11805200)
SASE FEL can generate intense and coherent linearly-polarized X-ray when high energy electron beams travelling through a long planar undulator. It is also of great importance and interest to control the polarization of FEL. One possible solution is utilizing a customized undulator to adjust the magnetic field direction. By tuning the displacement of the magnetic block arrangement, variation of polarization could be achieved. In this paper we study on a polarization controllable undulator to realize the variable polarized magnetic field. Different shapes and design considerations of the magnetic block configuration will be introduced. The value of peak field and the region of good field will be analysed and discussed.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB003

About •

Received ※ 01 July 2023 — Revised ※ 08 July 2023 — Accepted ※ 09 July 2023 — Issued ※ 20 July 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

space-charge, simulation, 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)

MOPB017

Analysis of the Fluctuation of Resonance Driving Terms for Nonlinear Lattice Optimization

sextupole, storage-ring, resonance, lattice

41

B.F. Wei, Z.H. Bai, G.Y. Feng, J.J. Tan
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Minimizing resonance driving terms (RDTs) of nonlinear magnets is a traditional approach to enlarge the dynamic aperture (DA) of a storage ring. The local cancellation of nonlinear dynamics, which is adopted by some diffraction-limited storage rings, is more effective than the global cancellation. The former has smaller fluctuation of RDTs along the ring. In this paper, the correlation between two kinds of RDT fluctuations is found. The qualitative analysis shows that minimizing the RDT fluctuations is beneficial for controlling the crossing terms and thus enlarging the DA. This qualitative analysis is supported by the statistical analysis of nonlinear solutions of a double-bend achromat lattice.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB017

About •

Received ※ 10 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 11 April 2024

Cite •

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

TUPB008

Evaluation of Field Quality for Elliptical and Curved Magnets

multipole, HOM, FFAG, octupole

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)