RF Structure Design for CSR-LINAC IH-RFQ

LI Zhongshan; DU Heng; YIN Xuejun; XIA Jiawen; YUAN Youjin; YANG Jiancheng; LI Xiaoni; LI Peng; LI Jie; ZHENG Wenheng; GE Wenwen; QU Guofeng; SHEN Guodong; ZHANG Xiaohu; QIAO Jian; WANG Kedong

doi:10.11804/NuclPhysRev.35.02.140

The 108.48 MHz IH type RFQ for CSR-LINAC project is under design at Institute of Modern Physics, Chinese Academy of Sciences. This RFQ can accelerate heavy ions with mass to charge ratio of 3~7 from 4 keV/u to 300 keV/u. According to the beam dynamics requirement, the RF structure design has been finished. The quadrupole field unflatness and dipole field of the cavity were studied by electromagnetic simulation and beam dynamics simulation. The frequency of the cavity without tuning is 108.15 MHz, the Q₀ of the cavity is 5910, and the RF power loss is 123 kW. The quadrupole field unflatness of ±2.5%,which was -21%~12% before optimizing, is achieved to meet dynamics requirement through the undercuts in cavity supporters. The dipole field of -3%~ -2.2% causes the oscillation of the beam center and acceptance reduction of 5%. The power coupler must be in critical coupling state with the coupling area of 940 mm² for minimum reflection coefficient. The tuners, consist of coarse and fine tuners with frequency shift of 707 and 132 kHz respectively, is used for tuning of frequency deviation of the cavity.

RF Structure Design for CSR-LINAC IH-RFQ

1. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China;

2. University of Chinese Academy of Sciences, Beijing 100049, China

Funds: Guangdong Innovative and Entrepreneurial Research Team Program (2016ZT06G373); National Natural Science Foundation of China (11375243, 11405237, 11475235)

Received Date: 2017-07-19

Rev Recd Date: 2017-10-12

Publish Date: 2018-06-20

Key words:

heavy ion radiofrequency quadrupole accelerator /
electromagnetic simulation /
unflatness of quadrupole field /
power coupler /
tuner

Abstract: The 108.48 MHz IH type RFQ for CSR-LINAC project is under design at Institute of Modern Physics, Chinese Academy of Sciences. This RFQ can accelerate heavy ions with mass to charge ratio of 3~7 from 4 keV/u to 300 keV/u. According to the beam dynamics requirement, the RF structure design has been finished. The quadrupole field unflatness and dipole field of the cavity were studied by electromagnetic simulation and beam dynamics simulation. The frequency of the cavity without tuning is 108.15 MHz, the Q₀ of the cavity is 5910, and the RF power loss is 123 kW. The quadrupole field unflatness of ±2.5%,which was -21%~12% before optimizing, is achieved to meet dynamics requirement through the undercuts in cavity supporters. The dipole field of -3%~ -2.2% causes the oscillation of the beam center and acceptance reduction of 5%. The power coupler must be in critical coupling state with the coupling area of 940 mm² for minimum reflection coefficient. The tuners, consist of coarse and fine tuners with frequency shift of 707 and 132 kHz respectively, is used for tuning of frequency deviation of the cavity.

HTML

Reference (24)

[1]	XIA Jiawen, ZHAN Wenlong, WEI Baowen, et al. Nucl Instr Meth A, 2002, 488(1):11.
[2]	ZHANG Xiaohu, YUAN Youjin, XIA Jiawen, et al. Chinese Physics C, 2014, 38(10):74.
[3]	ZHANG Xiaohu. Beam dynamics design and research of the Linac injectors in HIRFL[D]. Lanzhou:Institute of Modern Physics, Chinese Academy of Sciences, 2014:127. (in Chinese) (张小虎. HIRFL重离子直线注入器的动力学设计与研究[D]. 兰州:中国科学院近代物理研究所, 2014:127.)
[4]	JAMESON R A. NATO ASI Series B:Physics, 1988, 178:497.
[5]	LIU G, LU Y R, HE Y, et al. Nucl Instr Meth A, 2013, 701(3):186.
[6]	YIN X J, YUAN Y J, XIA J W, et al. Phys Rev ST Accel Beams, 2016, 19(1):010402.
[7]	LI C, SUN L, HE Y, et al. Nucl Instr Meth A, 2013, 729(1-2):426.
[8]	WANG Z J, HE Y, JIA H, et al. Proceedings of LINAC2012[C]. Tel-Aviv, Israel, 2012.
[9]	KLABUNDE J. Proceedings of the 1988 Linear Accelerator Conference[C]. Williamsburg, Virginia, USA, 2012.
[10]	KLABUNDE J. Proceedings of the 1992 Linear Accelerator Conference[C]. Ottawa, Ontario, Canada, 1992.
[11]	RATZINGER U, KASPAR K, MALWITZ E, et al. Nucl Instr Meth, 1998, 415(1):281.
[12]	KASPAR K, RATZINGER U. DESIGN OF THE GSI 36 MHZ RFQ ACCELERATOR ON THE BASE OF MAFIA CALCULATIONS, 1996.
[13]	KOSCIELNIAK S, LAXDAL R E, LEE R, et al. Particle Accelerator Conference, 1997[C]. Vancouver, British Columbia, Canada, 1997:1102.
[14]	LAXDAL R E, BAARTMAN R A, ROOT L. Proceedings of the 1999 Particle Accelerator Conference[C]. New York,1999:3534.
[15]	CRANDALL K R. Proceedings of the 1979 Linear Accelerator Conference[C]. Montauk, New York, USA, 1979:205.
[16]	ZHANG C, SCHEMPP A. Nucl Instr Meth A, 2008, 586(2):153.
[17]	ZHANG C, SCHEMPP A. Nucl Instr Meth A, 2009, 609(2-3):95.
[18]	CHUAN ZHANG. Linac Design for Intense Hadron Beams[D]. Frankfurt am Main, 2009(12):54.
[19]	KASPAR K, RATZINGER U. the 5th European Particle Accelerator Conference[C]. Sitges, Barcelona, Spain, 1996.
[20]	RATZINGER U, KASPAR K, MALWITZ E, et al. Nucl Instr Meth A, 1998, 415(1):281.
[21]	CST-Computer Simulation Technology. www.cst.com.
[22]	LIU Ge. Study on the Theoretical Design and Experimental Research of a Continuous Wave High Charge State Heavy Ion RFQ[D]. Beijing:Peking University, 2014:68. (in Chinese) (刘戈. 连续波高电荷态重离子RFQ加速器的理论设计与实验研究[D]. 北京大学, 2014:68.)
[23]	URIOT D. TraceWin[M]. CEA Saclay, 2013.
[24]	BAILEY R. Proceedings of the CAS-CERN Accelerator School:RF for accelerators, Ebeltoft, Denmark, 2011:125.

RF Structure Design for CSR-LINAC IH-RFQ

doi: 10.11804/NuclPhysRev.35.02.140

Abstract

References

Proportional views

通讯作者: 陈斌, bchen63@163.com

Article Metrics

Proportional views