CYCLOTRONS2022 - List of Keywords (coupling)

Paper	Title	Other Keywords	Page
WEPO017	A New Design of CYCIAE230 Superconducting Cyclotron RF-Driven System	cyclotron, cavity, electron, resonance	237
	Z.G. Yin, X.L. Fu, B. Ji, X. Mu, S. Pei, J.Y. Wei, T.J. Zhang CIAE, Beijing, People’s Republic of China
	A superconducting cyclotron with a beam energy of 246.2MeV has been developed and commissioned by the China Institute of Atomic Energy. The RF system of the first CYCIAE-230 cyclotron adopts two tetrode amplifiers to drive the cavities simultaneously. The driven power is 180 degrees out of phase and each of the amplifiers was designed able to deliver 75kW RF power to the cavities. In practice, it was found that the driven power is beyond necessary and only 80kW RF power is required for the beam. Hence, an upgrade of the existing RF-driven system to the stare-of-art of solid-state technology is put forward by the CIAE cyclotron team. Furthermore, this alternative design also includes an optimization of the coupling between amplifiers and the cavities, since the old coupler shows nonidealities under long-term high-power operations. A driven schema utilizing multiple low-power capacitive couplers is designed to address this issue, taking advantage of the cavity as a power combiner. In this paper, a review of the existing RF-driven system will be given first. It will be followed by an analysis of the limitation of such a system in practice. A new design of the solid amplifier, the new driven method, and a capacitive window will also be reported.
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO017
About •	Received ※ 25 December 2022 — Revised ※ 29 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 02 June 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRBO04	Error Magnetic Field due to the Median Plane Asymmetry and Its Applications in the Cyclotron	survey, cyclotron, resonance, 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

WEPO017

A New Design of CYCIAE230 Superconducting Cyclotron RF-Driven System

cyclotron, cavity, electron, resonance

237

Z.G. Yin, X.L. Fu, B. Ji, X. Mu, S. Pei, J.Y. Wei, T.J. Zhang
CIAE, Beijing, People’s Republic of China

A superconducting cyclotron with a beam energy of 246.2MeV has been developed and commissioned by the China Institute of Atomic Energy. The RF system of the first CYCIAE-230 cyclotron adopts two tetrode amplifiers to drive the cavities simultaneously. The driven power is 180 degrees out of phase and each of the amplifiers was designed able to deliver 75kW RF power to the cavities. In practice, it was found that the driven power is beyond necessary and only 80kW RF power is required for the beam. Hence, an upgrade of the existing RF-driven system to the stare-of-art of solid-state technology is put forward by the CIAE cyclotron team. Furthermore, this alternative design also includes an optimization of the coupling between amplifiers and the cavities, since the old coupler shows nonidealities under long-term high-power operations. A driven schema utilizing multiple low-power capacitive couplers is designed to address this issue, taking advantage of the cavity as a power combiner. In this paper, a review of the existing RF-driven system will be given first. It will be followed by an analysis of the limitation of such a system in practice. A new design of the solid amplifier, the new driven method, and a capacitive window will also be reported.

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO017

About •

Received ※ 25 December 2022 — Revised ※ 29 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 02 June 2023

Cite •

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

FRBO04

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

survey, cyclotron, resonance, 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)