LINAC2018 - List of Authors (He, Y.)

Paper	Title	Page
MOPO087	Cold Test of Hybrid RFQ Prototype	184
SPWR012	use link to see paper's listing under its alternate paper code
	P.Y. Yu, Y. He, C.X. Li, F.F. Wang, Z.J. Wang, B. Zhang IMP/CAS, Lanzhou, People’s Republic of China
	Hybrid RFQ is proposed as a potential good choice at the low-energy range of linear accelerator, which is combined by four-vane RFQ structure and CH-DTL structure. It has higher energy gain rate compared to conventional RFQ, and it is more compact than traditional DTL. In order to research on process exploration and RF parameters of this structure, an aluminium prototype is developed. The cold test of Hybrid RFQ prototype is completed. This paper will present the results and analysis of the test.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO087
About •	paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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TUPO003	Development of CW Heavy Ion Linac at IMP	326
TUOP08	use link to see paper's listing under its alternate paper code
	X. Yin, H. Du, Y. He, Q.Y. Kong, X.N. Li, Z.S. Li, L.Z. Ma, J. Meng, C. Qian, L.T. Sun, K.D. Wang, J.X. Wu, J.W. Xia, W.J. Xie, Z. Xu, Y.Q. Yang, Q.G. Yao, Y.J. Yuan, W. Zhang, X.Z. Zhang, Y. Zhang, H.W. Zhao, Z.Z. Zhou IMP/CAS, Lanzhou, People’s Republic of China J.E. Chen, S.L. Gao, G. Liu, Y.R. Lu, Z. Wang, X.Q. Yan, K. Zhu PKU, Beijing, People’s Republic of China
	A new heavy ion linac as the injector for the Separated Sector Cyclotron (SSC), named SSC-Linac[1], is being under constructed at the national laboratory Heavy Ion Research Facility in Lanzhou (HIRFL). The SSC-Linac mainly consists of a 4-rod RFQ and three IH-DTL cavities which can accelerate ion of A⁄q≤7from 3.73 keV/u to 1.025 MeV/u. Both of themoperating at 53.667MHz had been developed. In the commissioning, ions weresuccessfully accelerated to 0.295MeV/u by IH-DTL1. The beam commissioningof the IH-DTL2 which can accelerate the ion to 0.586MeV/u will come soon. In this paper, the recent R&D progress of the SSC-Linac including the development of key components and the beam commissioning results arepresented.
	Slides TUPO003 [7.335 MB]
	Poster TUPO003 [0.810 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO003
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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TUPO036	Vertical Test Results of Plasma In-situ Cleaning on Low Beta HWR Cavity	408
TUOP06	use link to see paper's listing under its alternate paper code
	A.D. Wu, H. Guo, Y. He, C.F. Hu, S.C. Huang, C.L. Li, Y.M. Li, X. Liu, F. Pan, Y.K. Song, P.R. Xiong, L. Yang, W.M. Yue, C. Zhang, S.H. Zhang, H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China
	Field emission occurred in SRF cavity is the major limitation to operate at high gradient with stability. The plasma in-situ cleaning for the low beta HWR cavity was carried out to remove the hydrocarbons contaminants on the inner cavity surface. And the vertical test results indicated that the field emission effect was relieved with the increasing of the quench point and emission set-on point. Thus, oxygen active plasma processing can be an effective method to solve the field emission issues for the low beta HWR cavity.
	Slides TUPO036 [1.281 MB]
	Poster TUPO036 [0.672 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO036
About •	paper received ※ 11 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019
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TUPO038	Several Experimental Phenomena of Sn Nucleation on Nb Surface Observed at IMP	412
TUPO037	use link to see paper's listing under its alternate paper code
	Z.Q. Yang, Y. He, F. Pan IMP/CAS, Lanzhou, People’s Republic of China
	Nucleation process is an important step that affects the quality of Nb3Sn films coated by vapor diffusion method. A uniform distribution of nucleation centers is essential to the uniformity of Nb3Sn films. In this paper we report several experimental phenomena on the Sn nucleation on Nb surface. Better nucleation in the downstream of the pumping direction was observed. Influence of SnCl2 partial pressure inhomogeneity was studied. Samples with higher SnCl2 partial pressure have denser nucleation, which means homogeneous SnCl2 pressure is a critical factor to the uniform nucleation. Less-nuclear zones, mainly distributed at cracks, grain boundaries and even some whole grain surfaces, were found on the surfaces of all samples. The less-nuclear zones may result in the low tin regions of the Nb3Sn cavities. The specific solution to the less-nuclear problem was proposed. These studies help to better understanding of the mechanism underlying the nucleation process and will be useful foundation for the follow-up Nb3Sn/Nb project at IMP.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO038
About •	paper received ※ 12 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019
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TUPO106	Mathematical Principle and Numerical Reconstruction in Real Space Measurement with a Rotating BPM	560
	P. Jiang, Y. He, Z.J. Wang IMP/CAS, Lanzhou, People’s Republic of China
	It is difficult to measure beam profiles and monitor the beam during beam supply for high intensity high power accelerators. Based on the button pick-ups, the mathematical principle of a rotating BPM is proposed. SVD method is used to reconstruct the beam in x-y real space, and the basic parameters used in beam reconstruction are argued. The beam distribution in x-y real space is reconstructed well and compared to the reference beam. The beam reconstruction is sensitive to the electrode radius. The meshing and the grid numbers in the solution window have an import effect on the beam reconstruction.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO106
About •	paper received ※ 12 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019
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THPO050	Research on the New Cavity Structure of RFQ Accelerator With Bent Vanes at IMP	802
THOP03	use link to see paper's listing under its alternate paper code
	L. Yang, T. He, Y. He, C.X. Li, L. Lu, L.P. Sun, C.C. Xing IMP/CAS, Lanzhou, People’s Republic of China L. Yang University of Chinese Academy of Sciences, Beijing, People’s Republic of China
	A new cavity structure of RFQ accelerator with bent vanes is proposed to meet the miniaturization requirement of low frequency heavy ion accelerators at Institute of Modern Physics (IMP), Chinese Academy of Sciences. The new structure has a downsized cross section by bending vanes while keeping a certain vane lengths. It also possesses the advantages of simple cooling structure and high power efficient when used in low frequency. The new structure has obvious advantages in reducing manufacturing difficulty of cavity, cutting down project cost, enhancing facility reliability and stability.
	Slides THPO050 [1.407 MB]
	Poster THPO050 [0.398 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO050
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO051	The Multi-physics Analysis of LEAF RFQ	805
	X.B. Xu, T. He, Y. He, C.X. Li, L. Lu, W. Ma, A. Shi, L.B. Shi, L.P. Sun, C.C. Xing, L. Yang, H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China
	The 81.25 MHz CW RFQ is designed to accelerate heavy ions with Q/A from 1/7 to 1/2 at 0.5 MeV/u for the Low Energy Accelerator Facility (LEAF) at the Institute of Modern Physics (IMP) of the Chinese Academy of Science (CAS). The four-vane RFQ consists of six mod-ules with a total length of 5.95 meters, For the CW oper-ating mode, thermal management will be a very important issue, Therefore a multi-physics analysis is necessary to ensure that the cavity can stably operate at the high RF power . The multi-physics analysis process includes RF electromagnetic analysis, thermal analysis, mechanical analysis, and the frequency shift, the cooling water system is used for frequency tunning by the temperature adjustment, and also analyze RFQ undercuts, fixed tuners, and pi-mode rods, the results show that the thermal and structural design of this RFQ is reasonable.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO051
About •	paper received ※ 17 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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THPO052	High Power Test of the LEAF-RFQ	808
	L. Lu, Y. He, W. Ma, L.B. Shi, L.T. Sun, L.P. Sun, L. Yang, Y. Yang, H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China
	High power heavy ion drivers require a CW low-frequency accelerator for initial acceleration. A CW four-vane radio frequency quadrupole (RFQ) accelerator is designed to accelerate heavy ions A/q up to 7 from 14 keV/u to 500 keV/u, as a new injector for the Low Energy Accelerator Facility (LEAF) at Institute of Modern Physics (IMP). The measurements of low power test were reported previously. In this paper, the results of high power test of the RFQ, including the test of the acceleration systems and beam profiles, will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO052
About •	paper received ※ 07 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019
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THPO053	Status of the China Material Irradiation Facility RFQ	811
	C.X. Li, W.L. Chen, W.P. Dou, Z. Gao, Y. He, G. Huang, C.L. Li, L. Lu, W. Ma, A. Shi, L.B. Shi, L.P. Sun, F.F. Wang, W.B. Wang, Z.J. Wang, Q. Wu, X.B. Xu, L. Yang, P.Y. Yu, B. Zhang, J.H. Zhang, P. Zhang, T.M. Zhu IMP/CAS, Lanzhou, People’s Republic of China
	Funding: Supported by the National Magnetic Confinement Fusion Science Program of China (Grant No.2014GB104001) and the National Natural Science Foundation of China (Grant No.91426303). The pulsed high power test and beam test of the China Material Irradiation Facility RFQ have been implemented. Before this, the radio frequency measurements and tuning are performed. In this paper, the processes and results of the radio frequency measurements, tuning, pulsed high power test and beam test will be presented. The results of tests are in good agreement with the design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO053
About •	paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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THPO054	Recent Progress of a CW 4-rod RFQ for the SSC-LINAC	814
	Z.S. Li, Y. Cong, H. Du, Y. He, L. Jing, Q.Y. Kong, X.N. Li, J. Meng, G.D. Shen, K.D. Wang, Z.J. Wang, W. Wei, J.X. Wu, J.W. Xia, H.M. Xie, W.J. Xie, Z. Xu, J.C. Yang, Y.Q. Yang, X. Yin, Y.J. Yuan, Y. Zhang IMP/CAS, Lanzhou, People’s Republic of China Y.R. Lu PKU, Beijing, People’s Republic of China
	The SSC-LINAC is under design and construction as a linear injector for the Separated-Sector Cyclotron (SSC) of the Heavy Ion Research Facility at Lanzhou (HIRFL). The continuous-wave (CW) 4-rod radio-frequency quad-rupole (RFQ) of the SSC-LINAC has important progress in past years. In the autumn of 2016, the cavity has been operated with 35 kW on CW mode in automatic RF con-trolled mode during RF power commissioning, which is needed to accelerate 238U³⁴⁺ beams. The beam transmis-sion efficiency, transverse emittance and energy spread has been obtained in beam commissioning. In this paper, the results of experiments will be presented and discussed in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO054
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO068	AN Effect of Field Emission on Low Beta Superconducting Cavities	849
SPWR011	use link to see paper's listing under its alternate paper code
	X. Liu, Z. Gao, Y. He, G. Huang IMP/CAS, Lanzhou, People’s Republic of China
	Superconducting RF (SRF) technology is widely ap-plied in particle accelerators to shorten the accelerator length and lower the construction price due to its high acceleration gradients with low rf losses. Field emission is the chief limitation associated with the surface electric field which will finally determine the cavity performance during the operation. The pickup-drop signal caused by field emission seriously affect the stable operation of the superconducting linac in the Chinese initiative Accelera-tor-Driven Sub-critical System (CiADS) demon facility. Simulations of the field emission effect and experimental measurements of the pickup-drop signal have been per-formed on the half wavelength resonator (HWR) cavity. And a modified design of the pickup antenna will be discussed to solve the pickup-drop problem.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO068
About •	paper received ※ 12 September 2018 paper accepted ※ 09 October 2018 issue date ※ 18 January 2019
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THPO069	The Electromagnetic Optimization of TE-sample Host Cavity at IMP	852
	S.C. Huang, Y. He, T. Tan, S.X. Zhang IMP/CAS, Lanzhou, People’s Republic of China
	As a part of the research and development work of thin-film materials for superconducting radio frequency(SRF) application in future accelerators at IMP, a 3.9GHz TE sample host cavity is being developed for the purpose of characterizing the RF Property and the loss mechanism of thin-film materials, which operates in the TE011 mode and accommodates disk sample with 110mm diameter, theoretically, the maximum magnetic field on sample surface will go up to 100mT, the resolution of surface resistance on sample will below nOhm by using thermometry technique( T-Mapping). In this paper, the electromagnetic optimization result of TE-sample host cavity will be presented, and the design consideration of hook tip style coupler and T-mapping system are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO069
About •	paper received ※ 12 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019
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THPO090	The Analysis of Module Failure in High Solid-state Amplifier for High Current RFQ	886
	L.P. Sun, Y. He, G. Huang, C.X. Li, L. Lu, A. Shi, L.B. Shi, X.B. Xu, H.W. Zhao IMP/CAS, Lanzhou, People’s Republic of China
	New accelerator RF system was upgraded to the solid-state amplifier in ADS project due to its stable, sustainable and reliable. Until now, newest 80kW SSA was adopted in IMP, operating in 162.5MHz, and over 120 power modules were combined through several synthesizers for 80kW output. but since too many modules were optimized for amplitude and phase in the same time, one or some failure of circulator will lead to injure of whole RF system, when wavelength meets a specific condition, injure would turn out severe accident and heavy loss. In this paper, analyzing and simulating the multi-level synthetic matrix was the important method for ADS accident happened in June 20. 2017, the failure simulated results for RF amplify links under the specific circumstances also was presented simultaneously.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO090
About •	paper received ※ 17 September 2018 paper accepted ※ 31 October 2018 issue date ※ 18 January 2019
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Paper

Title

Page

MOPO087

Cold Test of Hybrid RFQ Prototype

184

SPWR012

use link to see paper's listing under its alternate paper code

P.Y. Yu, Y. He, C.X. Li, F.F. Wang, Z.J. Wang, B. Zhang
IMP/CAS, Lanzhou, People’s Republic of China

Hybrid RFQ is proposed as a potential good choice at the low-energy range of linear accelerator, which is combined by four-vane RFQ structure and CH-DTL structure. It has higher energy gain rate compared to conventional RFQ, and it is more compact than traditional DTL. In order to research on process exploration and RF parameters of this structure, an aluminium prototype is developed. The cold test of Hybrid RFQ prototype is completed. This paper will present the results and analysis of the test.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO087

About •

paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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TUPO003

Development of CW Heavy Ion Linac at IMP

326

TUOP08

use link to see paper's listing under its alternate paper code

X. Yin, H. Du, Y. He, Q.Y. Kong, X.N. Li, Z.S. Li, L.Z. Ma, J. Meng, C. Qian, L.T. Sun, K.D. Wang, J.X. Wu, J.W. Xia, W.J. Xie, Z. Xu, Y.Q. Yang, Q.G. Yao, Y.J. Yuan, W. Zhang, X.Z. Zhang, Y. Zhang, H.W. Zhao, Z.Z. Zhou
IMP/CAS, Lanzhou, People’s Republic of China
J.E. Chen, S.L. Gao, G. Liu, Y.R. Lu, Z. Wang, X.Q. Yan, K. Zhu
PKU, Beijing, People’s Republic of China

A new heavy ion linac as the injector for the Separated Sector Cyclotron (SSC), named SSC-Linac[1], is being under constructed at the national laboratory Heavy Ion Research Facility in Lanzhou (HIRFL). The SSC-Linac mainly consists of a 4-rod RFQ and three IH-DTL cavities which can accelerate ion of A⁄q≤7from 3.73 keV/u to 1.025 MeV/u. Both of themoperating at 53.667MHz had been developed. In the commissioning, ions weresuccessfully accelerated to 0.295MeV/u by IH-DTL1. The beam commissioningof the IH-DTL2 which can accelerate the ion to 0.586MeV/u will come soon. In this paper, the recent R&D progress of the SSC-Linac including the development of key components and the beam commissioning results arepresented.

Slides TUPO003 [7.335 MB]

Poster TUPO003 [0.810 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO003

About •

paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

Export •

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

TUPO036

Vertical Test Results of Plasma In-situ Cleaning on Low Beta HWR Cavity

408

TUOP06

use link to see paper's listing under its alternate paper code

A.D. Wu, H. Guo, Y. He, C.F. Hu, S.C. Huang, C.L. Li, Y.M. Li, X. Liu, F. Pan, Y.K. Song, P.R. Xiong, L. Yang, W.M. Yue, C. Zhang, S.H. Zhang, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

Field emission occurred in SRF cavity is the major limitation to operate at high gradient with stability. The plasma in-situ cleaning for the low beta HWR cavity was carried out to remove the hydrocarbons contaminants on the inner cavity surface. And the vertical test results indicated that the field emission effect was relieved with the increasing of the quench point and emission set-on point. Thus, oxygen active plasma processing can be an effective method to solve the field emission issues for the low beta HWR cavity.

Slides TUPO036 [1.281 MB]

Poster TUPO036 [0.672 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO036

About •

paper received ※ 11 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019

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TUPO038

Several Experimental Phenomena of Sn Nucleation on Nb Surface Observed at IMP

412

TUPO037

use link to see paper's listing under its alternate paper code

Z.Q. Yang, Y. He, F. Pan
IMP/CAS, Lanzhou, People’s Republic of China

Nucleation process is an important step that affects the quality of Nb3Sn films coated by vapor diffusion method. A uniform distribution of nucleation centers is essential to the uniformity of Nb3Sn films. In this paper we report several experimental phenomena on the Sn nucleation on Nb surface. Better nucleation in the downstream of the pumping direction was observed. Influence of SnCl2 partial pressure inhomogeneity was studied. Samples with higher SnCl2 partial pressure have denser nucleation, which means homogeneous SnCl2 pressure is a critical factor to the uniform nucleation. Less-nuclear zones, mainly distributed at cracks, grain boundaries and even some whole grain surfaces, were found on the surfaces of all samples. The less-nuclear zones may result in the low tin regions of the Nb3Sn cavities. The specific solution to the less-nuclear problem was proposed. These studies help to better understanding of the mechanism underlying the nucleation process and will be useful foundation for the follow-up Nb3Sn/Nb project at IMP.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO038

About •

paper received ※ 12 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019

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

TUPO106

Mathematical Principle and Numerical Reconstruction in Real Space Measurement with a Rotating BPM

560

P. Jiang, Y. He, Z.J. Wang
IMP/CAS, Lanzhou, People’s Republic of China

It is difficult to measure beam profiles and monitor the beam during beam supply for high intensity high power accelerators. Based on the button pick-ups, the mathematical principle of a rotating BPM is proposed. SVD method is used to reconstruct the beam in x-y real space, and the basic parameters used in beam reconstruction are argued. The beam distribution in x-y real space is reconstructed well and compared to the reference beam. The beam reconstruction is sensitive to the electrode radius. The meshing and the grid numbers in the solution window have an import effect on the beam reconstruction.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO106

About •

paper received ※ 12 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019

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

THPO050

Research on the New Cavity Structure of RFQ Accelerator With Bent Vanes at IMP

802

THOP03

use link to see paper's listing under its alternate paper code

L. Yang, T. He, Y. He, C.X. Li, L. Lu, L.P. Sun, C.C. Xing
IMP/CAS, Lanzhou, People’s Republic of China
L. Yang
University of Chinese Academy of Sciences, Beijing, People’s Republic of China

A new cavity structure of RFQ accelerator with bent vanes is proposed to meet the miniaturization requirement of low frequency heavy ion accelerators at Institute of Modern Physics (IMP), Chinese Academy of Sciences. The new structure has a downsized cross section by bending vanes while keeping a certain vane lengths. It also possesses the advantages of simple cooling structure and high power efficient when used in low frequency. The new structure has obvious advantages in reducing manufacturing difficulty of cavity, cutting down project cost, enhancing facility reliability and stability.

Slides THPO050 [1.407 MB]

Poster THPO050 [0.398 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO050

About •

paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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THPO051

The Multi-physics Analysis of LEAF RFQ

805

X.B. Xu, T. He, Y. He, C.X. Li, L. Lu, W. Ma, A. Shi, L.B. Shi, L.P. Sun, C.C. Xing, L. Yang, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

The 81.25 MHz CW RFQ is designed to accelerate heavy ions with Q/A from 1/7 to 1/2 at 0.5 MeV/u for the Low Energy Accelerator Facility (LEAF) at the Institute of Modern Physics (IMP) of the Chinese Academy of Science (CAS). The four-vane RFQ consists of six mod-ules with a total length of 5.95 meters, For the CW oper-ating mode, thermal management will be a very important issue, Therefore a multi-physics analysis is necessary to ensure that the cavity can stably operate at the high RF power . The multi-physics analysis process includes RF electromagnetic analysis, thermal analysis, mechanical analysis, and the frequency shift, the cooling water system is used for frequency tunning by the temperature adjustment, and also analyze RFQ undercuts, fixed tuners, and pi-mode rods, the results show that the thermal and structural design of this RFQ is reasonable.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO051

About •

paper received ※ 17 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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THPO052

High Power Test of the LEAF-RFQ

808

L. Lu, Y. He, W. Ma, L.B. Shi, L.T. Sun, L.P. Sun, L. Yang, Y. Yang, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

High power heavy ion drivers require a CW low-frequency accelerator for initial acceleration. A CW four-vane radio frequency quadrupole (RFQ) accelerator is designed to accelerate heavy ions A/q up to 7 from 14 keV/u to 500 keV/u, as a new injector for the Low Energy Accelerator Facility (LEAF) at Institute of Modern Physics (IMP). The measurements of low power test were reported previously. In this paper, the results of high power test of the RFQ, including the test of the acceleration systems and beam profiles, will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO052

About •

paper received ※ 07 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019

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THPO053

Status of the China Material Irradiation Facility RFQ

811

C.X. Li, W.L. Chen, W.P. Dou, Z. Gao, Y. He, G. Huang, C.L. Li, L. Lu, W. Ma, A. Shi, L.B. Shi, L.P. Sun, F.F. Wang, W.B. Wang, Z.J. Wang, Q. Wu, X.B. Xu, L. Yang, P.Y. Yu, B. Zhang, J.H. Zhang, P. Zhang, T.M. Zhu
IMP/CAS, Lanzhou, People’s Republic of China

Funding: Supported by the National Magnetic Confinement Fusion Science Program of China (Grant No.2014GB104001) and the National Natural Science Foundation of China (Grant No.91426303).
The pulsed high power test and beam test of the China Material Irradiation Facility RFQ have been implemented. Before this, the radio frequency measurements and tuning are performed. In this paper, the processes and results of the radio frequency measurements, tuning, pulsed high power test and beam test will be presented. The results of tests are in good agreement with the design.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO053

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paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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THPO054

Recent Progress of a CW 4-rod RFQ for the SSC-LINAC

814

Z.S. Li, Y. Cong, H. Du, Y. He, L. Jing, Q.Y. Kong, X.N. Li, J. Meng, G.D. Shen, K.D. Wang, Z.J. Wang, W. Wei, J.X. Wu, J.W. Xia, H.M. Xie, W.J. Xie, Z. Xu, J.C. Yang, Y.Q. Yang, X. Yin, Y.J. Yuan, Y. Zhang
IMP/CAS, Lanzhou, People’s Republic of China
Y.R. Lu
PKU, Beijing, People’s Republic of China

The SSC-LINAC is under design and construction as a linear injector for the Separated-Sector Cyclotron (SSC) of the Heavy Ion Research Facility at Lanzhou (HIRFL). The continuous-wave (CW) 4-rod radio-frequency quad-rupole (RFQ) of the SSC-LINAC has important progress in past years. In the autumn of 2016, the cavity has been operated with 35 kW on CW mode in automatic RF con-trolled mode during RF power commissioning, which is needed to accelerate 238U³⁴⁺ beams. The beam transmis-sion efficiency, transverse emittance and energy spread has been obtained in beam commissioning. In this paper, the results of experiments will be presented and discussed in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO054

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paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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THPO068

AN Effect of Field Emission on Low Beta Superconducting Cavities

849

SPWR011

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X. Liu, Z. Gao, Y. He, G. Huang
IMP/CAS, Lanzhou, People’s Republic of China

Superconducting RF (SRF) technology is widely ap-plied in particle accelerators to shorten the accelerator length and lower the construction price due to its high acceleration gradients with low rf losses. Field emission is the chief limitation associated with the surface electric field which will finally determine the cavity performance during the operation. The pickup-drop signal caused by field emission seriously affect the stable operation of the superconducting linac in the Chinese initiative Accelera-tor-Driven Sub-critical System (CiADS) demon facility. Simulations of the field emission effect and experimental measurements of the pickup-drop signal have been per-formed on the half wavelength resonator (HWR) cavity. And a modified design of the pickup antenna will be discussed to solve the pickup-drop problem.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO068

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paper received ※ 12 September 2018 paper accepted ※ 09 October 2018 issue date ※ 18 January 2019

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THPO069

The Electromagnetic Optimization of TE-sample Host Cavity at IMP

852

S.C. Huang, Y. He, T. Tan, S.X. Zhang
IMP/CAS, Lanzhou, People’s Republic of China

As a part of the research and development work of thin-film materials for superconducting radio frequency(SRF) application in future accelerators at IMP, a 3.9GHz TE sample host cavity is being developed for the purpose of characterizing the RF Property and the loss mechanism of thin-film materials, which operates in the TE011 mode and accommodates disk sample with 110mm diameter, theoretically, the maximum magnetic field on sample surface will go up to 100mT, the resolution of surface resistance on sample will below nOhm by using thermometry technique( T-Mapping). In this paper, the electromagnetic optimization result of TE-sample host cavity will be presented, and the design consideration of hook tip style coupler and T-mapping system are also discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO069

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paper received ※ 12 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019

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THPO090

The Analysis of Module Failure in High Solid-state Amplifier for High Current RFQ

886

L.P. Sun, Y. He, G. Huang, C.X. Li, L. Lu, A. Shi, L.B. Shi, X.B. Xu, H.W. Zhao
IMP/CAS, Lanzhou, People’s Republic of China

New accelerator RF system was upgraded to the solid-state amplifier in ADS project due to its stable, sustainable and reliable. Until now, newest 80kW SSA was adopted in IMP, operating in 162.5MHz, and over 120 power modules were combined through several synthesizers for 80kW output. but since too many modules were optimized for amplitude and phase in the same time, one or some failure of circulator will lead to injure of whole RF system, when wavelength meets a specific condition, injure would turn out severe accident and heavy loss. In this paper, analyzing and simulating the multi-level synthetic matrix was the important method for ADS accident happened in June 20. 2017, the failure simulated results for RF amplify links under the specific circumstances also was presented simultaneously.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO090

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paper received ※ 17 September 2018 paper accepted ※ 31 October 2018 issue date ※ 18 January 2019

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