Field tuning and rf measurements of the four-vane radio frequency quadrupole with ramped inter-vane voltage

Content Provider	Directory of Open Access Journals (DOAJ)
Author	Q. Z. Xing X. D. Yu Q. K. Guo P. F. Ma Y. Lei S. X. Zheng Y. Li S. Wang K. Liu X. L. Guan X. W. Wang B. C. Wang C. Zhao Z. M. Wang
Abstract	This paper describes the physical design, rf measurement, and tuning result of a 325 MHz four-vane radio frequency quadrupole (RFQ) with a ramped inter-vane voltage. The 3-meter-long RFQ will accelerate the negative hydrogen ion beam from 50 keV to 3 MeV with a peak current of 5 mA, a pulse width of 10–40  μs, and a maximum repetition rate of 0.5 Hz. During tuning we reveal that the coupling loop of the coaxial coupler adopted for this RFQ enhances the interference between the dipole field distribution and the coupling coefficient. Therefore, an iteration method is adopted to simultaneously achieve the desired field distribution and coupling coefficient. After tuning, the relative error between the measured field distribution and the designed curve for the operating quadrupole mode is within ±2.7%, and the dipole components are about ±1.9% of the quadrupole mode. The measured coupling coefficient of the rf power coupler equals 1.03, with the desired value of 1.04.
Related Links	http://doi.org/10.1103/PhysRevAccelBeams.22.020102
e-ISSN	24699888
DOI	10.1103/PhysRevAccelBeams.22.020102
Journal	Physical Review Accelerators and Beams
Issue Number	2
Volume Number	22
Language	English
Publisher	American Physical Society
Publisher Date	2019-01-01
Publisher Place	United States
Access Restriction	Open
Subject Keyword	Nuclear and particle physics. Atomic energy. Radioactivity
Content Type	Text
Resource Type	Article