HB2023 - List of Authors (Liu, Y.)

Paper	Title	Page
WEC4I2	Development of Dual-harmonic RF System for CSNS-II	312
	X. Li, X. Li, W. Long, W.J. Wu, C.L. Zhang IHEP, Beijing, People’s Republic of China Y. Liu DNSC, Dongguan, People’s Republic of China B. Wu IHEP CSNS, Guangdong Province, People’s Republic of China
	The upgrade of the China Spallation Neutron Source (CSNS-II) encompasses the development of a dual har-monic RF system for the Rapid Cycling Synchrotron (RCS). The objective of this system is to achieve a maxi-mum second harmonic voltage of 100 kV. To meet this requirement, a high gradient cavity is being used in place of the traditional ferrite loaded cavity. Magnetic alloy (MA) loaded cavities, which can attain very high field gradients, have demonstrated their suitability for high-intensity proton synchrotrons. As a result, designing an RF system with MA-loaded cavities has emerged as a primary focus. Over the past decade, substantial ad-vancements have been made in the development of MA-loaded cavities at CSNS. This paper provides an overview of the RF system that incorporates the MA-loaded cavity and presents the high-power test results of the system.
	Slides WEC4I2 [6.449 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC4I2
About •	Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 22 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRA1I2	Design and Beam Commissioning of Dual Harmonic RF System in CSNS RCS	633
	H.Y. Liu, L. Huang IHEP CSNS, Guangdong Province, People’s Republic of China Y. Liu DNSC, Dongguan, People’s Republic of China S. Wang, S.Y. Xu IHEP, Beijing, People’s Republic of China
	The CSNS accelerator achieved an average beam power on target of 100 kW in February 2020 and subsequently increased it to 125 kW in March 2022. Building upon this success, CSNS plans to further enhance the average beam power to 200 kW by doubling the particle number of the circulating beam in the RCS, while keeping the injection energy same. The space charge effect is a main limit for the beam intensity increase in high-power particle accelerators. By providing a second harmonic RF cavity with a harmonic number of 4, in combination with the ferrite cavity with a harmonic number of 2, the dual harmonic RF system aims to mitigate emittance increase and beam loss caused by space charge effects, thereby optimizing the longitudinal beam distribution. This paper will concentrate on the beam commissioning for the 140 kW operation subsequent to the installation of the magnetic alloy (MA) cavity. The commissioning process includes the optimization of RF parameters, beam studies, and evaluation of the beam quality and instability.
	Slides FRA1I2 [4.086 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-FRA1I2
About •	Received ※ 30 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 14 October 2023 — Issued ※ 27 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Development of Dual-harmonic RF System for CSNS-II

312

X. Li, X. Li, W. Long, W.J. Wu, C.L. Zhang
IHEP, Beijing, People’s Republic of China
Y. Liu
DNSC, Dongguan, People’s Republic of China
B. Wu
IHEP CSNS, Guangdong Province, People’s Republic of China

The upgrade of the China Spallation Neutron Source (CSNS-II) encompasses the development of a dual har-monic RF system for the Rapid Cycling Synchrotron (RCS). The objective of this system is to achieve a maxi-mum second harmonic voltage of 100 kV. To meet this requirement, a high gradient cavity is being used in place of the traditional ferrite loaded cavity. Magnetic alloy (MA) loaded cavities, which can attain very high field gradients, have demonstrated their suitability for high-intensity proton synchrotrons. As a result, designing an RF system with MA-loaded cavities has emerged as a primary focus. Over the past decade, substantial ad-vancements have been made in the development of MA-loaded cavities at CSNS. This paper provides an overview of the RF system that incorporates the MA-loaded cavity and presents the high-power test results of the system.

Slides WEC4I2 [6.449 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC4I2

About •

Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 22 October 2023

Cite •

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

FRA1I2

Design and Beam Commissioning of Dual Harmonic RF System in CSNS RCS

633

H.Y. Liu, L. Huang
IHEP CSNS, Guangdong Province, People’s Republic of China
Y. Liu
DNSC, Dongguan, People’s Republic of China
S. Wang, S.Y. Xu
IHEP, Beijing, People’s Republic of China

The CSNS accelerator achieved an average beam power on target of 100 kW in February 2020 and subsequently increased it to 125 kW in March 2022. Building upon this success, CSNS plans to further enhance the average beam power to 200 kW by doubling the particle number of the circulating beam in the RCS, while keeping the injection energy same. The space charge effect is a main limit for the beam intensity increase in high-power particle accelerators. By providing a second harmonic RF cavity with a harmonic number of 4, in combination with the ferrite cavity with a harmonic number of 2, the dual harmonic RF system aims to mitigate emittance increase and beam loss caused by space charge effects, thereby optimizing the longitudinal beam distribution. This paper will concentrate on the beam commissioning for the 140 kW operation subsequent to the installation of the magnetic alloy (MA) cavity. The commissioning process includes the optimization of RF parameters, beam studies, and evaluation of the beam quality and instability.

Slides FRA1I2 [4.086 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-FRA1I2

About •

Received ※ 30 September 2023 — Revised ※ 09 October 2023 — Accepted ※ 14 October 2023 — Issued ※ 27 October 2023

Cite •

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