LINAC2018 - Classification: Proton and Ion Accelerators and Applications / RFQs

Paper	Title	Page
TUPO015	The CW Beam Experiment of Window-type RFQ
TUOP11	use link to see paper's listing under its alternate paper code
	K. Zhu PKU, Beijing, People’s Republic of China
	Funding: work supported by NSFC. Grand No. 2014CB845503 A window-type RFQ is designed and fabricated by Peking University. It is planed to accelerate 50mA deuteron cw beam to 1MeV. The 60kV intervane voltage is designed to decrease the risk of high voltage discharge since the RFQ works in cw mode. High power test shows that the intervane voltage is over 60kV when the Cavity power consumption is 48kW. The beam experiment was done and 1.8mA cw beam was obtained at exit of RFQ with over 90% transmission efficiency. This paper will present the cold model measurement, high power RF conditioning and beam experiment result.
	Slides TUPO015 [2.051 MB]
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THPO047	SPIRAL2 Injector Commissioning	790
THOP01	use link to see paper's listing under its alternate paper code
	R. Ferdinand, M. Di Giacomo, H. Franberg, O. Kamalou, J.-M. Lagniel, G. Normand, A. Savalle, F. Varenne GANIL, Caen, France D. Uriot CEA/DRF/IRFU, Gif-sur-Yvette, France
	The SPIRAL2 injector is composed of two ion sources (p/d and heavy ions up to A/Q=3) followed by a 730 keV/u RFQ. Beam commissioning has started in 2014 in parallel with the superconducting linac and HEBT installations. The RFQ beam commissioning started soon after the first RF conditioning done in October 2015. This paper describes the RFQ beam measurements done on the diagnostic plate for the reference particles (H⁺, 4He2+ and recently 18O6+) and the difficulties encountered for the RFQ commissioning at the A/Q=3 field level.
	Slides THPO047 [7.846 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO047
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO048	Low Power Measurement of a 1300-MHz RFQ Cold Model	794
THOP02	use link to see paper's listing under its alternate paper code
	Y. Kondo, T. Morishita, J. Tamura JAEA/J-PARC, Tokai-mura, Japan M. Otani KEK, Ibaraki, Japan
	Funding: This work is supported by JSPS KAKENHI Grant Number 17K18784. A muon linac development for a new muon g-2/EDM experiment is now going on at J-PARC. Muons from the muon beam line (H-line) of the J-PARC muon facility are once stopped in a silica aerojel target and room temperature muoniums are evaporated from the aerogel. They are dissociated with the lasers to be the ultra slow muons, then accelerated up to 212 MeV using a linear accelerator. The low energy part of this muon linac consists of a 324-MHz RFQ and an IH DTL. The frequency is increased to 1296 MHz at the following CCL section. We propose to replace the low energy section to a 1300-MHz RFQ to simplify the configuration of the muon linac. The 1300-MHz RFQ will be extremely small compared to conventional RFQs, therefore we made a cold model to proof the feasibility of this scheme. In this paper, the result of low-power measurement of the 1300-MHz RFQ cold model is described.
	Slides THPO048 [2.160 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO048
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO049	Field Tuning of a Radio-frequency Quadrupole Using Full 3D Modeling	798
	T. Morishita, K. Hasegawa, Y. Kondo, H. Oguri JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan M. Otani KEK, Ibaraki, Japan
	The radio-frequency quadrupole linac (RFQ) is operating in the frontend of the J-PARC linac to accelerates 50 mA negative hydrogen beams from 0.05 MeV to 3 MeV. As a backup, the spare RFQ has been fabricated in 2018. The vane-voltage ramping is adopted to improve the acceleration efficiency so that the cross-sectional shape is adjusted longitudinally to produce the designed voltage distribution. Then, the three-dimensional cavity models including modulations and cutbacks were created in CST Micro-Wave Studio. The vane-base widths and cutback depths were optimized to produce the desired vane-voltage distribution. In the final tuning, the heights of the stub turners were also determined based on the tuner responses obtained from the full 3D models. In this paper, the detailed design process of the cavity dimensions and the result of the low-power measurements are described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO049
About •	paper received ※ 12 September 2018 paper accepted ※ 20 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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THPO057	Redesign of CERN Linac3 RFQ for Lead 29+	818
	S. Benedetti, G. Bellodi, J.-B. Lallement, A.M. Lombardi CERN, Geneva, Switzerland
	CERN Linac3 is at the start of the CERN Heavy Ion Facility, providing 4.2 MeV/u ion beams to the Low Energy Ion Ring (LEIR). It mostly accelerates 208Pb²⁹⁺, though in recent years runs were performed with 40Ar¹¹⁺ and 129Xe²²⁺, in view of the increasing interest of the physics community towards lighter ions experiments. In the framework of the LHC Injectors Upgrade (LIU) project, measurements and beam dynamics simulations showed that a transmission bottleneck of Linac3 is represented by the RFQ. As this accelerator was originally designed for 208Pb²⁵⁺, the lower beam rigidity of the heavy ions currently in use and planned for the future permits a redesign of the RFQ optics aimed at increasing its transverse acceptance, and thus the transmitted beam current. A study of this has been performed, and the methodology adopted and the results are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO057
About •	paper received ※ 11 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019
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THPO058	RF Design of a High-frequency RFQ Linac for PIXE Analysis	822
SPWR016	use link to see paper's listing under its alternate paper code
THOP04	use link to see paper's listing under its alternate paper code
	H.W. Pommerenke, A. Bilton, A. Grudiev, A.M. Lombardi, S.J. Mathot, E. Montesinos, M.A. Timmins, M. Vretenar CERN, Geneva, Switzerland H.W. Pommerenke, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: This work has been sponsored by the Wolfgang Gentner Program of the German Federal Ministry of Education and Research (grant no. 05E12CHA). Protons with an energy of few MeV are commonly used for Ion Beam Analysis of materials, in particular with the Proton Induced X-ray Emission technique (PIXE). Because of its non-damaging character, PIXE is used in a variety of fields, in particular for the diagnosis of cultural heritage artwork. A compact accelerator based on a high frequency RFQ (Radio Frequency Quadrupole) linac has been designed and is being built at CERN. The length of the RFQ is only one meter and it allows the acceleration of a proton beam up to an energy of 2 MeV. The complete system is conceived to be transportable, allowing PIXE analysis almost anywhere. This paper covers the RF design of the compact RFQ operating at 750 MHz. We present general accelerator parameters and the current state of the RF design, which includes RFQ geometry and coupler design, thermal simulation and first particle tracking results.
	Slides THPO058 [2.404 MB]
	Poster THPO058 [2.192 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO058
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO060	First RF Measurements of the 325 MHz Ladder RFQ	826
	M. Schuett, U. Ratzinger, M. Syha IAP, Frankfurt am Main, Germany
	Funding: BMBF 05P15RFRBA Based on the positive results of the unmodulated 325 MHz Ladder-RFQ prototype from 2013 to 2016, we developed and designed a modulated 3.3 m Ladder-RFQ. The unmodulated prototype Ladder-RFQ features a very constant voltage along the axis. The RFQ was high power tested at the GSI test stand. It accepted 3 times the RF power level needed in operation. That level corresponds to a Kilpatrick factor of 3.1 with a pulse length of 200 µs. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the proton linac within the FAIR project. This particular high frequency creates difficulties for a 4-ROD type RFQ, which triggered the development of a Ladder RFQ with its higher symmetry. The results of the unmodulated prototype have shown, that the Ladder-RFQ is a suitable candidate for that frequency. For the present design duty cycles are feasible up to 5%. The basic design and tendering of the RFQ has been successfully completed in 2016. Manufacturing will be completed in August 2018. We will show the the finalization of manufacturing as well as first low level RF measurements of the Ladder RFQ. Journal of Physics: Conf. Series 874 (2017) 012048 **Proceedings of LINAC2016, East Lansing, TUPLR053
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO060
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO061	Beam Characterization of the MYRRHA-RFQ	830
SPWR017	use link to see paper's listing under its alternate paper code
	P.P. Schneider, M. Droba, O. Meusel, H. Podlech, A. Schempp IAP, Frankfurt am Main, Germany D. Noll CERN, Geneva, Switzerland
	Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) #05P15RFRBA and HORIZON 2020 for the MYRRHA project #662186 and HIC for FAIR. The Linear Accelerator for the MYRRHA project* is under construction. In a first step the linac up to 100 MeV will be realized. The LEBT section has been set into operation in Belgium and the RFQ is installed in summer 2018. A system to analyze the ion beam consisting of a slit-grid emittance scanner, a beam dump and a momentum spectrometer, called diagnostic train descripted in *, will be set on the rails to characterize the beam at the RFQ injection point. The results will be used to adjust the optimal matching for the RFQ. After the measurements downstream the LEBT, the diagnostic train begins its journey along the beam line and at the first station the RFQ is installed. The accelerated beam of the RFQ is then analyzed and optimized. In addition to optimization of transmission the artificial production of beam offsets in the LEBT is of special interest. These will be measured at the injection point to estimate the range of possible offsets. In the following measurements these offsets will be used to study the influence of the offsets on the RFQ performance. Furthermore, the RFQ parameters are varied to see their influence on the beam transport, transmission and beam quality. H.Aı̈t Abderrahim et al. "MYRRHA: A multipurpose accelerator driven system for research & development", 2001 ** 1st Experiments at the CW-Operated RFQ for Intense Proton Beams, LINAC16
	Poster THPO061 [4.610 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO061
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO062	IFMIF/EVEDA RFQ Preliminary Beam Characterization	834
	E. Fagotti, L. Antoniazzi, L. Bellan, M. Comunian, F. Grespan, M. Montis, A. Palmieri, A. Pisent, F. Scantamburlo INFN/LNL, Legnaro (PD), Italy T. Akagi, K. Kondo, K. Sakamoto, T. Shinya, M. Sugimoto QST, Aomori, Japan P. Cara IFMIF/EVEDA, Rokkasho, Japan H. Dzitko, I.M. Moya F4E, Germany R. Heidinger, A. Marqueta Fusion for Energy, Garching, Germany I. Podadera CIEMAT, Madrid, Spain
	The IFMIF/EVEDA RFQ is the longest and powerful operated. Therefore, it requires a careful characterization from several aspects: beam dynamics, RF, mechanics, installation and commissioning. Due to the very large power handling, the preliminary beam operation was decided to be performed with a low proton beam current at one half of the voltage needed for deuteron accelera-tion, i.e. from 8 mA to 30 mA at 2.5 MeV in pulsed mode, with respect to the nominal 130-mA deuteron beam at 5 MeV in CW. In this framework, it will be presented the characterization of the RFQ in terms of simulation and measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO062
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO064	Tuning of a Four-vane RFQ for Xi’an 200 MeV Proton Application Facility	838
	X.D. Yu, X. Guan, Q.K. Guo, Y. Lei, P.F. Ma, X.W. Wang, Q.Z. Xing, S.X. Zheng TUB, Beijing, People’s Republic of China B.C. Wang, Z.M. Wang, C. Zhao NINT, Shannxi, People’s Republic of China
	This paper mainly describes the procedures and results of tuning a four-vane Radio Frequency Quadrupole (RFQ) accelerator for the Xi’an 200 MeV Proton Application Facility (XiPAF) project. The 3-meter-long RFQ will accelerate a 50 keV H⁻ beam from the ECR source to 3 MeV, and deliver it to the downstream drift tube linac (DTL) with a peak current of 5 mA, pulse length of 10-40 μs and maximum repetition rate of 0.5. The machining, assembly, and RF tuning of the RFQ cavity has been completed successfully. After tuning, the relative error of the operating quadrupole mode field is within ±2.7%, and the dipole mode com-ponent is within ±1.9% of the quadrupole mode. The RFQ now is ready for high-power RF conditioning.
	Poster THPO064 [1.413 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO064
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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Paper

Title

Page

TUPO015

The CW Beam Experiment of Window-type RFQ

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

K. Zhu
PKU, Beijing, People’s Republic of China

Funding: work supported by NSFC. Grand No. 2014CB845503
A window-type RFQ is designed and fabricated by Peking University. It is planed to accelerate 50mA deuteron cw beam to 1MeV. The 60kV intervane voltage is designed to decrease the risk of high voltage discharge since the RFQ works in cw mode. High power test shows that the intervane voltage is over 60kV when the Cavity power consumption is 48kW. The beam experiment was done and 1.8mA cw beam was obtained at exit of RFQ with over 90% transmission efficiency. This paper will present the cold model measurement, high power RF conditioning and beam experiment result.

Slides TUPO015 [2.051 MB]

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THPO047

SPIRAL2 Injector Commissioning

790

THOP01

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

R. Ferdinand, M. Di Giacomo, H. Franberg, O. Kamalou, J.-M. Lagniel, G. Normand, A. Savalle, F. Varenne
GANIL, Caen, France
D. Uriot
CEA/DRF/IRFU, Gif-sur-Yvette, France

The SPIRAL2 injector is composed of two ion sources (p/d and heavy ions up to A/Q=3) followed by a 730 keV/u RFQ. Beam commissioning has started in 2014 in parallel with the superconducting linac and HEBT installations. The RFQ beam commissioning started soon after the first RF conditioning done in October 2015. This paper describes the RFQ beam measurements done on the diagnostic plate for the reference particles (H⁺, 4He2+ and recently 18O6+) and the difficulties encountered for the RFQ commissioning at the A/Q=3 field level.

Slides THPO047 [7.846 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO047

About •

paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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THPO048

Low Power Measurement of a 1300-MHz RFQ Cold Model

794

THOP02

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

Y. Kondo, T. Morishita, J. Tamura
JAEA/J-PARC, Tokai-mura, Japan
M. Otani
KEK, Ibaraki, Japan

Funding: This work is supported by JSPS KAKENHI Grant Number 17K18784.
A muon linac development for a new muon g-2/EDM experiment is now going on at J-PARC. Muons from the muon beam line (H-line) of the J-PARC muon facility are once stopped in a silica aerojel target and room temperature muoniums are evaporated from the aerogel. They are dissociated with the lasers to be the ultra slow muons, then accelerated up to 212 MeV using a linear accelerator. The low energy part of this muon linac consists of a 324-MHz RFQ and an IH DTL. The frequency is increased to 1296 MHz at the following CCL section. We propose to replace the low energy section to a 1300-MHz RFQ to simplify the configuration of the muon linac. The 1300-MHz RFQ will be extremely small compared to conventional RFQs, therefore we made a cold model to proof the feasibility of this scheme. In this paper, the result of low-power measurement of the 1300-MHz RFQ cold model is described.

Slides THPO048 [2.160 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO048

About •

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

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THPO049

Field Tuning of a Radio-frequency Quadrupole Using Full 3D Modeling

798

T. Morishita, K. Hasegawa, Y. Kondo, H. Oguri
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
M. Otani
KEK, Ibaraki, Japan

The radio-frequency quadrupole linac (RFQ) is operating in the frontend of the J-PARC linac to accelerates 50 mA negative hydrogen beams from 0.05 MeV to 3 MeV. As a backup, the spare RFQ has been fabricated in 2018. The vane-voltage ramping is adopted to improve the acceleration efficiency so that the cross-sectional shape is adjusted longitudinally to produce the designed voltage distribution. Then, the three-dimensional cavity models including modulations and cutbacks were created in CST Micro-Wave Studio. The vane-base widths and cutback depths were optimized to produce the desired vane-voltage distribution. In the final tuning, the heights of the stub turners were also determined based on the tuner responses obtained from the full 3D models. In this paper, the detailed design process of the cavity dimensions and the result of the low-power measurements are described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO049

About •

paper received ※ 12 September 2018 paper accepted ※ 20 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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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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

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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.

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

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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.

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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.

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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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THPO057

Redesign of CERN Linac3 RFQ for Lead 29+

818

S. Benedetti, G. Bellodi, J.-B. Lallement, A.M. Lombardi
CERN, Geneva, Switzerland

CERN Linac3 is at the start of the CERN Heavy Ion Facility, providing 4.2 MeV/u ion beams to the Low Energy Ion Ring (LEIR). It mostly accelerates 208Pb²⁹⁺, though in recent years runs were performed with 40Ar¹¹⁺ and 129Xe²²⁺, in view of the increasing interest of the physics community towards lighter ions experiments. In the framework of the LHC Injectors Upgrade (LIU) project, measurements and beam dynamics simulations showed that a transmission bottleneck of Linac3 is represented by the RFQ. As this accelerator was originally designed for 208Pb²⁵⁺, the lower beam rigidity of the heavy ions currently in use and planned for the future permits a redesign of the RFQ optics aimed at increasing its transverse acceptance, and thus the transmitted beam current. A study of this has been performed, and the methodology adopted and the results are presented.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO057

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

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THPO058

RF Design of a High-frequency RFQ Linac for PIXE Analysis

822

SPWR016

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

THOP04

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

H.W. Pommerenke, A. Bilton, A. Grudiev, A.M. Lombardi, S.J. Mathot, E. Montesinos, M.A. Timmins, M. Vretenar
CERN, Geneva, Switzerland
H.W. Pommerenke, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Funding: This work has been sponsored by the Wolfgang Gentner Program of the German Federal Ministry of Education and Research (grant no. 05E12CHA).
Protons with an energy of few MeV are commonly used for Ion Beam Analysis of materials, in particular with the Proton Induced X-ray Emission technique (PIXE). Because of its non-damaging character, PIXE is used in a variety of fields, in particular for the diagnosis of cultural heritage artwork. A compact accelerator based on a high frequency RFQ (Radio Frequency Quadrupole) linac has been designed and is being built at CERN. The length of the RFQ is only one meter and it allows the acceleration of a proton beam up to an energy of 2 MeV. The complete system is conceived to be transportable, allowing PIXE analysis almost anywhere. This paper covers the RF design of the compact RFQ operating at 750 MHz. We present general accelerator parameters and the current state of the RF design, which includes RFQ geometry and coupler design, thermal simulation and first particle tracking results.

Slides THPO058 [2.404 MB]

Poster THPO058 [2.192 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO058

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paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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THPO060

First RF Measurements of the 325 MHz Ladder RFQ

826

M. Schuett, U. Ratzinger, M. Syha
IAP, Frankfurt am Main, Germany

Funding: BMBF 05P15RFRBA
Based on the positive results of the unmodulated 325 MHz Ladder-RFQ prototype from 2013 to 2016, we developed and designed a modulated 3.3 m Ladder-RFQ*. The unmodulated prototype Ladder-RFQ features a very constant voltage along the axis. The RFQ was high power tested at the GSI test stand. It accepted 3 times the RF power level needed in operation**. That level corresponds to a Kilpatrick factor of 3.1 with a pulse length of 200 µs. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the proton linac within the FAIR project. This particular high frequency creates difficulties for a 4-ROD type RFQ, which triggered the development of a Ladder RFQ with its higher symmetry. The results of the unmodulated prototype have shown, that the Ladder-RFQ is a suitable candidate for that frequency. For the present design duty cycles are feasible up to 5%. The basic design and tendering of the RFQ has been successfully completed in 2016. Manufacturing will be completed in August 2018. We will show the the finalization of manufacturing as well as first low level RF measurements of the Ladder RFQ.
*Journal of Physics: Conf. Series 874 (2017) 012048
**Proceedings of LINAC2016, East Lansing, TUPLR053

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO060

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

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THPO061

Beam Characterization of the MYRRHA-RFQ

830

SPWR017

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P.P. Schneider, M. Droba, O. Meusel, H. Podlech, A. Schempp
IAP, Frankfurt am Main, Germany
D. Noll
CERN, Geneva, Switzerland

Funding: This work is supported by the German Federal Ministry of Education and Research (BMBF) #05P15RFRBA and HORIZON 2020 for the MYRRHA project #662186 and HIC for FAIR.
The Linear Accelerator for the MYRRHA project* is under construction. In a first step the linac up to 100 MeV will be realized. The LEBT section has been set into operation in Belgium and the RFQ is installed in summer 2018. A system to analyze the ion beam consisting of a slit-grid emittance scanner, a beam dump and a momentum spectrometer, called diagnostic train descripted in **, will be set on the rails to characterize the beam at the RFQ injection point. The results will be used to adjust the optimal matching for the RFQ. After the measurements downstream the LEBT, the diagnostic train begins its journey along the beam line and at the first station the RFQ is installed. The accelerated beam of the RFQ is then analyzed and optimized. In addition to optimization of transmission the artificial production of beam offsets in the LEBT is of special interest. These will be measured at the injection point to estimate the range of possible offsets. In the following measurements these offsets will be used to study the influence of the offsets on the RFQ performance. Furthermore, the RFQ parameters are varied to see their influence on the beam transport, transmission and beam quality.
* H.Aı̈t Abderrahim et al. "MYRRHA: A multipurpose accelerator driven system for research & development", 2001
** 1st Experiments at the CW-Operated RFQ for Intense Proton Beams, LINAC16

Poster THPO061 [4.610 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO061

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

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THPO062

IFMIF/EVEDA RFQ Preliminary Beam Characterization

834

E. Fagotti, L. Antoniazzi, L. Bellan, M. Comunian, F. Grespan, M. Montis, A. Palmieri, A. Pisent, F. Scantamburlo
INFN/LNL, Legnaro (PD), Italy
T. Akagi, K. Kondo, K. Sakamoto, T. Shinya, M. Sugimoto
QST, Aomori, Japan
P. Cara
IFMIF/EVEDA, Rokkasho, Japan
H. Dzitko, I.M. Moya
F4E, Germany
R. Heidinger, A. Marqueta
Fusion for Energy, Garching, Germany
I. Podadera
CIEMAT, Madrid, Spain

The IFMIF/EVEDA RFQ is the longest and powerful operated. Therefore, it requires a careful characterization from several aspects: beam dynamics, RF, mechanics, installation and commissioning. Due to the very large power handling, the preliminary beam operation was decided to be performed with a low proton beam current at one half of the voltage needed for deuteron accelera-tion, i.e. from 8 mA to 30 mA at 2.5 MeV in pulsed mode, with respect to the nominal 130-mA deuteron beam at 5 MeV in CW. In this framework, it will be presented the characterization of the RFQ in terms of simulation and measurements.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO062

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

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THPO064

Tuning of a Four-vane RFQ for Xi’an 200 MeV Proton Application Facility

838

X.D. Yu, X. Guan, Q.K. Guo, Y. Lei, P.F. Ma, X.W. Wang, Q.Z. Xing, S.X. Zheng
TUB, Beijing, People’s Republic of China
B.C. Wang, Z.M. Wang, C. Zhao
NINT, Shannxi, People’s Republic of China

This paper mainly describes the procedures and results of tuning a four-vane Radio Frequency Quadrupole (RFQ) accelerator for the Xi’an 200 MeV Proton Application Facility (XiPAF) project. The 3-meter-long RFQ will accelerate a 50 keV H⁻ beam from the ECR source to 3 MeV, and deliver it to the downstream drift tube linac (DTL) with a peak current of 5 mA, pulse length of 10-40 μs and maximum repetition rate of 0.5. The machining, assembly, and RF tuning of the RFQ cavity has been completed successfully. After tuning, the relative error of the operating quadrupole mode field is within ±2.7%, and the dipole mode com-ponent is within ±1.9% of the quadrupole mode. The RFQ now is ready for high-power RF conditioning.

Poster THPO064 [1.413 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO064

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

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