CYCLOTRONS2022 - List of Keywords (survey)

Paper	Title	Other Keywords	Page
FRBO04	Error Magnetic Field due to the Median Plane Asymmetry and Its Applications in the Cyclotron	cyclotron, resonance, coupling, site	381
	L.G. Zhang, R.A. Baartman, Y. Bylinskii, T. Planche, Y.-N. Rao TRIUMF, Vancouver, Canada
	Cyclotrons have a median plane symmetric structure. But the pole’s geometric error and the unevenly magnetized soft iron give rise to non-zero asymmetrical fields in the geometric median plane. The asymmetric field can shift the vertical position of the beam. Moreover, The error of the tilted median plane can be the driving force when the tunes pass through coupling resonances. In this paper, we take the TRIUMF 500 MeV cyclotron as an example to study the asymmetric field resulting from imperfect median plane symmetry. An approach due to M. Gordon, and a highly accurate compact finite differentiation method are used to investigate the historical field survey data, which reveals redundancy in the survey data. The redundancy was used in this study to correct the error in the measurement data. Further, the median plane asymmetry field could be manipulated using trim coils or harmonic coils with top and bottom coil currents in opposite directions (’Br-mode’). Using the created asymmetric field, we improved the vertical tune measurement method to investigate the linear coupling resonance in TRIUMF 500 MeV cyclotron. Eventually, the coupling resonance is corrected and avoided using the available harmonic coils and trim coils.
	Slides FRBO04 [1.620 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRBO04
About •	Received ※ 29 December 2022 — Revised ※ 07 February 2023 — Accepted ※ 10 February 2023 — Issue date ※ 10 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

FRBO04

Error Magnetic Field due to the Median Plane Asymmetry and Its Applications in the Cyclotron

cyclotron, resonance, coupling, site

381

L.G. Zhang, R.A. Baartman, Y. Bylinskii, T. Planche, Y.-N. Rao
TRIUMF, Vancouver, Canada

Cyclotrons have a median plane symmetric structure. But the pole’s geometric error and the unevenly magnetized soft iron give rise to non-zero asymmetrical fields in the geometric median plane. The asymmetric field can shift the vertical position of the beam. Moreover, The error of the tilted median plane can be the driving force when the tunes pass through coupling resonances. In this paper, we take the TRIUMF 500 MeV cyclotron as an example to study the asymmetric field resulting from imperfect median plane symmetry. An approach due to M. Gordon, and a highly accurate compact finite differentiation method are used to investigate the historical field survey data, which reveals redundancy in the survey data. The redundancy was used in this study to correct the error in the measurement data. Further, the median plane asymmetry field could be manipulated using trim coils or harmonic coils with top and bottom coil currents in opposite directions (’Br-mode’). Using the created asymmetric field, we improved the vertical tune measurement method to investigate the linear coupling resonance in TRIUMF 500 MeV cyclotron. Eventually, the coupling resonance is corrected and avoided using the available harmonic coils and trim coils.

Slides FRBO04 [1.620 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRBO04

About •

Received ※ 29 December 2022 — Revised ※ 07 February 2023 — Accepted ※ 10 February 2023 — Issue date ※ 10 July 2023

Cite •

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