WEPMN —  Wednesday Posters (Monroe)   (06-May-15   16:00—18:00)

Paper	Title	Page
WEPMN003	The Magnetic Measurement for Low Magnetic Field Stability of Dipole Magnet for CEPC	2917
	Z. Zhang, F.S. Chen, H. Gengpresenter, B. Yin IHEP, Beijing, People's Republic of China
	The CEPC (China Electron-Positron Collider) project is in the pre-research stage. When the beam energy of booster is 120 GeV, the magnetic field of deflection magnet is 640 G. In order to save funds for scientific research, we are ready to select the injection energy for 6 GeV, this corresponds to a magnetic field about 32 G. In such a low magnetic field, the effects of earth's magnetic field and ambient temperature variations cannot be ignored. In this paper, first written the collection procedures for magnetic field value and ambient temperature values by Labview software, then used a one-dimensional probe to measure the background magnetic field for three directions (Bx, By, Bz) and the value of the ambient temperature values, the time of data collection for each direction are more than 24 hours (every minute collecting a set of values). Finally, plus the different currents (3A, 6A.. 15A) to the dipole magnet, the time of measured and the data collected by over 24 hours. Based on the results of the analysis of large amounts of data, summarized and analyzed the effect of Earth's magnetic field and ambient temperature for dipole magnet in a low magnetic field.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN003
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WEPMN004	Progress on the CSNS Power Supply System	2921
	X. Qi, H. Gengpresenter IHEP, Beijing, People's Republic of China
	The 1.6 GeV proton synchrotron proposed in the CSNS Project is a 25 Hz rapid-cycling synchrotron (RCS) with injection energy of 80 MeV. Beam power is aimed to 100 kW at 1.6 GeV. The power supply system consists of seven subsystems. Those power supplies have three operation modes: DC mode, AC plus DC mode and programmable pulse mode. This paper will introduce the Power supply system status in recent years. Power Supply, rapid-cycling synchrotron, serial resonant network
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN004
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WEPMN007	Research Development of High Precision Installation and Alignment System for HEPS	2924
	L. Wu, S.Y. Chen, C. H. Li, H. Qu, H.J. Wang, X.L. Wang IHEP, Beijing, People's Republic of China
	High Energy Photon Source (HEPS) is a proposed 6 GeV third generation light source with high brightness and ultra-low emittance. Because the measurement error of the traditional optical survey method in the girder and magnet installation can’t meet the tight alignment tolerance, the installation and alignment will not only rely on laser tracker and some other optical survey instruments. So HEPS is developing the research of high precision installation and alignment system which is consists of the design of auto-tuning girder based on beam alignment and research of vibrating wire alignment system based on magnetic measurement. This paper introduces the research development of installation and alignment system in storage ring of HEPS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN007
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WEPMN008	Material Test of Proton Beam Window for CSNS	2927
	H.J. Wang, L. Kang, H. Qu, L. Wupresenter, D.H. Zhu IHEP, Beijing, People's Republic of China
	The proton beam window (PBW) is one of the key devices of China Spallation Neutron Source (CSNS). Material selection is of particular importance. A5083-O was selected in the previous work, and recently the material tests were done. The tests showed the material has good microstructure, physical and mechanical performance. Creep lifetime was analyzed based on the creep test. All the experiment showed the selected material is qualified.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN008
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WEPMN009	Design and Thermal Analysis of ADS Beam Stop	2931
	M.X. Li, J.L. Wang, L. Wupresenter IHEP, Beijing, People's Republic of China
	ADS beam stop is an important device which required for the commissioning and accelerator tests of Accelerator Driven Sub-critical System (ADS), it is used to stop the beam which power is about 100kW and consume energy of the beam. This paper will present a triangular prism structure of the ADS beam stop, its mechanical design is described in detail, and there are numerous grooves and ribs in the cooling plates which is the core component of the beam stop. The thermal analysis is performed and its result proves that the triangular prism structure meet the design requirement. Key words：Beam stop, ADS, thermal analysis, triangular prism structure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN009
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WEPMN010	Analysis of the Electromagnetic Field in the Coupler of Normal Temperature Travelling-Wave Accelerating Tube	2934
	X. He, M. Hou IHEP, Beijing, People's Republic of China S. Shupresenter Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	With the developed requirement of the beam quality in modern accelerators, rapid development of all kinds of accelerating structures with different frequencies and materials have been achieved. However, the normal temperature travelling-wave (TW) accelerating structures which are widely used in Free Electron Laser (FEL) are still indispensable. For reducing the beam emittance, it is very important to optimize the symmetry of the high-order electromagnetic field in the coupler of such accelerating structures. In this paper, the symmetry of the electromagnetic field in TW accelerator couplers using different coupling mechanisms was analysed. A lot of design optimization as well as the result analysis work has been done for the three kinds of commonly used waveguide-coupled TW accelerating structures: single-feed electrical-coupling, dual-feed electrical-coupling using magic tee in feeding waveguide and dual-feed magnetic-coupling using J-type feeding waveguide. Finally, basing on lots of simulation results and the performances during the fabrication, measurement and RF conditioning of these three kinds of structures, the J-type racetrack coupler type is regarded as the best choice.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN010
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WEPMN011	RF Modulation Studies on the S-Band Pulse Compressor	2937
	S. Shu Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China F. Zhao IHEP, Beijing, People's Republic of China
	An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the peak power around the coupling irises is about 500 MW at the phase reversal time. In order to deal with the breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, RF phase modulation (PM) with flat-top output is considered. By using the CST Microwave Studio (MWS) transient solver, a new method was developed to simulate the time response of the pulse compressor. In addition, the theoretical and experimental results of the PM theory are also presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN011
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WEPMN012	Cathode Stalk Optimization for a 325 MHz Superconducting QWR Electron Gun	2940
	P.L. Fan, Y.M. Li, L. Lin, K.X. Liu, S.W. Quan, F. Zhu PKU, Beijing, People's Republic of China
	Funding: Work supported by National Basic Research Project (No. 2011CB808302) The structure of cathode stalk is very important for the performance of a superconducting QWR (Quarter Wave Resonator) gun. With improper design, RF power dissipation on the surface of cathode stalk and its surrounding tube can lead to a serious decrease of quality factor for superconducting QWR injector. We present here an optimized design of the cathode stalk for the 325 MHz superconducting QWR gun and special considerations are taken to minimize the power dissipation. The details of microwave simulation, beam dynamic simulation of the cavity with cathode stalks in different length, diameter and position are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN012
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WEPMN013	Development of DC-SRF Injector at Peking University	2944
	J.K. Hao, J.E. Chen, P.L. Fan, L.W. Feng, S. Huang, L. Lin, K.X. Liu, S.W. Quan, F. Wang, Zh.W. Wang, X.D. Wen, H.M. Xie, K. Zhao, F. Zhu PKU, Beijing, People's Republic of China
	DC-SRF electron injector, which combines a DC Pierce gun and a 3.5 cell 1.3 GHz superconductor cavity in a cryomodule, has been developed at Peking University. Based on the improvements of beam line, LLRF system and 2K cryogenic system, stable operation of the DC-SRF injector has been carried out recently. Electron beams with 3.4 MeV energy and the currents of ~1mA in a macro-pulse mode was obtained. As the first application of this DC-SRF injector, THz radiation produced with a 10 period undulator was also detected. The description of the experiment process and results will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN013
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WEPMN014	A C-band Deflecting Cavity Design for High-precision Bunch Length Measurement	2948
	J. Jiang, H.B. Chen, J. Shi, P. Wang TUB, Beijing, People's Republic of China
	Funding: NSFC 11375098 and 11327902 A standing wave RF deflecting structure has been designed as a tool for high-precision bunch length measurement. This 3-cell deflecting cavity is designed to operate at a frequency of 5.712GHz. In this paper, the RF design and thermal analysis of the deflecting cavity are introduced. We study the electromagnetic field distribution inside the cavity. The coupler design is also discussed. And the beam dynamics simulation is shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN014
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WEPMN015	Dark Current Imaging Experiment in an L-band RF Gun	2952
	J.H. Shao, H.B. Chen, J. Shi, D. Wang TUB, Beijing, People's Republic of China S.P. Antipov, S.V. Baryshev, C.-J. Jing, J.Q. Qiu Euclid TechLabs, LLC, Solon, Ohio, USA M.E. Conde, D.S. Doran, W. Gai, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Argonne, Illinois, USA F.Y. Wang, L. Xiao SLAC, Menlo Park, California, USA
	The localized high electric field enhancement or low work function is the trigger for strong field emission, which however has yet been well experimentally studied. Using an L-band photocathode gun test stand at Argonne Wakefield Accelerator Facility (AWA), we’ve constructed an imaging beam line to observe field emission current from predefined emitters on cathode. Preliminary experiment results are present. Future plan is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN015
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WEPMN016	Observation of Dark Current Dependence on Stored Energy in an L-Band RF Gun	2956
	J.H. Shao, H.B. Chen, J. Shi, D. Wang TUB, Beijing, People's Republic of China S.P. Antipov, S.V. Baryshev, C.-J. Jing, J.Q. Qiu Euclid TechLabs, LLC, Solon, Ohio, USA M.E. Conde, D.S. Doran, W. Gai, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski ANL, Argonne, Illinois, USA F.Y. Wang, L. Xiao SLAC, Menlo Park, California, USA
	A pin cathode has been installed into an L-band photocathode gun to study the influence of stored energy on field emission. The stored energy was varied by tuning the recess of the cathode in order to have the same E-field on the cathode tip. We have observed 5 times difference of dark current level at the same E-field, while by varying the stored energy by three fold. Dynamics study reveals the difference is not caused by transmission, but by emission process itself. We'll present experiment results and discuss possible mechanisms about the phenomena.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN016
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WEPMN017	High Power RF Radiation at W-band Based on Wakefields Excited by Intense Electron Beam	2960
	D. Wang, C.-X. Tang TUB, Beijing, People's Republic of China S.P. Antipov, C.-J. Jing, J.Q. Qiu Euclid TechLabs, LLC, Solon, Ohio, USA M.E. Conde, D.S. Doran, W. Gai, G. Ha, W. Liu, J.G. Power, E.E. Wisniewski ANL, Argonne, Illinois, USA
	We report the experiment design and preliminary results on high power RF generation at W-band based on coherent wakefields from the metallic periodic structure of 91 GHz PETS (power extraction and transfer structure), excited by intense electron beam at the Argonne Wakefield Accelerator (AWA) facility. The recently output RF power is 0.7 MW, with 67 MeV, 1.4 nC single electron beam going through the structure. The RF pulse length is 3.4 ns. We measure the energy loss of electron beam as reference to the RF generation, which agrees well with the simulation results. Next run is to increase the output RF power with higher charge and to excite coherent wakefields with electron bunch train. The output RF peak power is expected to be ~100 MW and the electrical field gradient can reach up to 400 MV/m, with RF pulse duration adjustable from few ns to 30 ns when excited with 5~10 nC charge in a single bunch and up to 32 sub bunches in total.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN017
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WEPMN018	Measurement of Cell-Cell Coupling Coefficient in Photocathode RF Gun	2963
	P. Wang, H.B. Chen, Q. Gao, J. Shi, L. Zhang TUB, Beijing, People's Republic of China
	A photocathode RF gun is under cold rest in Tsinghua University. We measured the single cavity frequency and the cell-cell coupling coefficient by the detuning method with high accuracy. We use a simplified model to illustrate the whole process of the measurement. The data obtained in the cold test seem to accord with that from the model very well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN018
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WEPMN019	Calorimetric Power Measurements in X-band High Power RF	2967
	X.W. Wu, H.B. Chen, L. Zhang TUB, Beijing, People's Republic of China N. Catalán Lasheras, B.J. Woolley, W. Wuensch CERN, Geneva, Switzerland
	With the aim to test prototype accelerating structures for CLIC at high-gradient, new klystron-based, X-band high power test stands are being built at CERN. These tests stands are referred to as Xboxes with Xbox1 and Xbox2 being already operational. Stainless steel loads are placed in the end of the Xbox-1 system to absorb the remaining power which comes out of the accelerating structure. Power information is important and needs to be measured precisely. A new power measuring method based on calorimetry is proposed independent from RF measurements subject to frequent calibration. The principles of the method and simulations are presented and the results of actual experimentation are used to validate the method. The results show calorimetric measurement is feasible method and have a good precision at this power level.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN019
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WEPMN021	Design and Research of Secondary Electron Emission Test Equipment with Low Electron Energy	2970
	Y.H. Xu, L. Fan, Y.Z. Hong, X.T. Pei, J. Wangpresenter, Y. Wang, W. Wei, B. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	In particle accelerators, the secondary electrons resulting from the interaction between particles and vacuum chamber have a great impact on beam quality. Especially for positron, proton and heavy ion accelerators, massive electrons lead to electron cloud, which affects the stability, energy, emittance and beam life adversely. We have studied the secondary electron emission (SEE) of metal used for accelerators. A secondary electron emission measurement system with low electron energy has been designed and used to measure the SEE yield of metal and non-evaporable getter materials. With the equipment, we have obtained the characteristic of the SEE yield of stainless steel and oxygen free copper (OFC).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN021
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WEPMN022	Optimization Design of Ti Cathode in Ceramic Pipe Film Coating Based on the Simulation Result of CST	2973
	J. Wang, L. Fan, Y.Z. Hong, X.T. Pei, Y. Wang, W. Wei, Y.H. Xu, B. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	The injection chamber at Hefei Light Source II (HLS II) consists of four ceramic vacuum chambers whose inner surface were coated with TiN thin film. The cross section of ceramic pipes is special racetrack structure. In order to improve the uniformity of the film, the structure of the cathode Ti plate needed to be optimized. In this article, CST PARTICLE STUDIOTM software had been used to simulate the influence of different target structure on discharge electric field distribution and electrons trajectories. Furthermore, the reliability of the simulation were analysed compared with the experimental results. Also, we put forward the optimization design of Ti cathode structure which could satisfy the requirement of uniformity of the thin film.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN022
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WEPMN023	Vacuum System of the Storage Ring of HLS-II	2976
	Y. Wang, L. Fan, Y.Z. Hong, X.T. Pei, J. Wangpresenter, W. Wei, B. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	HLS storage-ring has been operated for more than twenty-five years. In 2014 we began to upgrade the machine, which is called HLS-II. The emittance is reduced to 40 nmrad, five insertion devices are added and the injection energy increases to 800MeV. Now the machine commissioning has already been completed. The typical life time is 300 mins at 300mA, 800MeV. The average pressure of static and dynamic vacuum are below 2×10-8 Pa and 1.2×10-7 Pa respectively. The design, installation and commissioning of the vacuum system of the storage ring are detailedly stated in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN023
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WEPMN024	Exploration of Multi-fold Symmetry Element-loaded Superconducting Radio Frequency Structure for Reliable Acceleration of Low- & Medium-Beta Ion Species	2978
	S.C. Huang IMP/CAS, Lanzhou, People's Republic of China R.L. Geng JLab, Newport News, Virginia, USA
	Reliable acceleration of low- to medium-beta proton or heavy ion species is needed for future high current superconducting radio frequency accelerators. Due to the high-Q nature of a superconducting RF resonator, it is sensitive to many factors such as loading variation (from either the accelerated beam or from parasitic field emitted electrons), mechanical vibration, and liquid helium bath pressure fluctuation etc. To increase the stability against those factors, a mechanically strong and stable RF structure is desirable. Guided by this consideration, multi-fold symmetry element-loaded superconducting radio frequency structures, cylindrical tanks with multiple (n>=3) rod-shaped radial elements, are being explored. The top goal of its optimization is to improve mechanical stability. A natural consequence of this structure is a lowered ratio of the peak surface electromagnetic field to the acceleration gradient as compared to the traditional spoke cavity. A disadvantage of this new structure is an increased size for a fixed resonant frequency and optimal beta. This paper describes the optimization of EM design and preliminary mechanical analysis for such structures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN024
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WEPMN025	Harmonic Resonant Kicker Design for the MEIC Electron Circular Cooler Ring	2981
	Y.L. Huang IMP/CAS, Lanzhou, People's Republic of China R.A. Rimmer, H. Wang, S. Wang JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S.DOE Contract No. DE-AC05-06OR23177. Bunched-beam electron cooling of the high-energy ion beam emittance may be a crucial technology for the proposed Medium energy Electron Ion Collider (MEIC) to achieve its design luminosity. A critical component is a fast kicker system in the Circular Ring (CR) that periodically switches electron bunches in and out of the ring from and to the driver Energy Recovery Linac (ERL). Compared to a conventional strip-line type kicker, a quarter wave resonator (QWR) based deflecting structure has a much higher shunt impedance and so requires much less RF power. The cavity has been designed to resonate simultaneously at many harmonic modes that are integer multiples of the fundamental mode. In this way the resulting waveform will kick only a subset of the circulating bunches. In this paper, analytical shunt impedance optimization, the electromagnetic simulations of this type of cavity, as well as tuner and coupler concept designs to produce 5 odd and 5 even harmonics of 47.63MHz will be presented, in order to kick every 10th bunch in a 476.3 MHz bunch train.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN025
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WEPMN026	Development of Non-resonant Perturbing Method for Tuning Traveling Wave Deflecting Structures	2985
	J.H. Tan, W. Fang, Q. Gu, Z.T. Zhao SINAP, Shanghai, People's Republic of China D.C. Tong TUB, Beijing, People's Republic of China
	For traveling wave accelerating structures, the tuning method assisted by bead pull technique based on non-resonant perturbation field distribution measurement has been widely used. Long periodic traveling wave deflecting structure, which operating at HEM11 mode, is difficult to use non-resonant perturbation method, and a improved method has been developed for measuring and tuning by "cage" type perturbing object at SINAP. The measurements on x-band traveling wave deflecting structure are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN026
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WEPMN028	Preliminary Mechanical Design of Ceramic Pipe Film Coating Equipment at Hefei Light Source II	2988
	J. Lu NPU, Xi'an Shaanxi, People's Republic of China L. Fan, Y.Z. Hong, X.T. Pei, J. Wangpresenter, Y. Wang, W. Wei, Y.H. Xu, B. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Ceramic vacuum chambers are important components of the injection chamber at Hefei Light Source II (HLS II). The length of each Ceramic vacuum chamber is 350 mm and their inner surface is coated with TiN thin film whose properties are low secondary electron yield (SEY), good electrical conductivity, stability of performance, ability to block hydrogen permeation. Considering that the cross section of Ceramic pipe is racetrack structure, Ti plate was chose as the cathode to improve TiN thin film deposition rate. Meanwhile, the authors designed a motor drive magnetron sputtering film coating equipment to obtain uniform TiN film.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN028
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WEPMN030	Testing Procedures for Fast Frequency Tuners of XFEL Cavities	2991
	K.P. Przygoda, W. Cichalewski, T. Pożniak TUL-DMCS, Łódź, Poland J. Branlard, O. Hensler, H. Schlarb, Ch. Schmidt DESY, Hamburg, Germany K. Kasprzak IFJ-PAN, Kraków, Poland
	The XFEL accelerator will be equipped with 100 accelerating modules. Each accelerating module will host 8 superconducting cavities. Every single cavity will be equipped with a mechanical tuner. Coarse tuning will be supported by a step motor; fine tuning will be handled by double piezoelectric elements installed inside a single mechanical support, providing actuator and sensor functionality or redundancy. Before the main linac installation, all its subcomponents need to be tested and verified. The AMTF (Accelerator Module Test Facility) has been built at DESY to test all XFEL cryomodules. In total 1600 piezos need to be tested. Test procedures for fast frequency tuners have been developed to check their basic performance in cryogenic conditions (tuning range, polarity, acting and sensing abilities). High level applications perform fully automated tests including report generation. After the successful completion of the acceptance tests, the cryomodules will be prepared for tunnel installation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN030
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WEPMN031	Automated Quench Limit Test Procedure for Serial Production of XFEL RF Cavities	2994
	K. Kasprzak, D. Konwisorz, K. Krzysik, S. Myalski, J. Świerbleski, K. Turaj, M. Wiencek, A. Zwozniak IFJ-PAN, Kraków, Poland D. Kostin, K.P. Przygodapresenter DESY, Hamburg, Germany
	In the Accelerator Module Test Facility (AMTF) at DESY in Hamburg RF cavities and accelerating cryomodules are tested for the European X-ray Free Electron Laser (XFEL). Measurements are done by a team of physicists, engineers and technicians from The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences in Kraków, Poland, as a part of Polish in-kind contribution to the XFEL. The testing procedures providing information about maximum available gradient and heat loads measurement are performed for the high gradients (up to 31MV/m). During these tests the cavity deformation caused by the Lorentz force is compensated by piezo (fast) tuners. For this purpose automated high level software was developed. This paper describes a method used to tune automatically the cavities during the RF tests. It was validated with the XFEL cryomodules. This improvement was implemented into the testing software and it is successfully used for testing of serial production cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN031
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WEPMN032	Microphonic Disturbances Prediction and Compensation in Pulsed Superconducting Accelerators	2997
	R. Rybaniec, L.J. Opalski Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland V. Ayvazyan, Ł. Butkowski, S. Pfeiffer, K.P. Przygodapresenter, H. Schlarb, Ch. Schmidt DESY, Hamburg, Germany
	Accelerators are affected by the cavities detuning variation caused by external mechanical disturbances (microphonics). The paper presents microphonics estimation and prediction methods applicable for superconducting accelerators operating in pulsed mode. A mathematical model is built using the estimates of detuning during previous RF pulses. The model can be used for predictions of disturbances for the future time step and setup of the fast tuners accordingly. The proposed method was successfully verified with measurements conducted at the FLASH linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN032
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WEPMN033	The Fabrication of Prototype Normal Conducting Rebuncher for the MEBT in RISP	3000
	H.J. Kim, M.O. Hyun, B.-S. Park IBS, Daejeon, Republic of Korea
	The Medium Energy Beam Transport (MEBT) system of RAON consists of several quadrupole magnets for controlling the transverse beam parameter at the entrance of the low energy linac, three normal-conducting (NC) re-bunchers to match the longitudinal beam ellipse into the acceptance of the low energy linac and several diagnostic devices. The NC QWR re-buncher, which has a frequency of 81.25 MHz, a geometric beta factor of 0.032, and an effective length of 24 cm, has been fabricated and tested to demonstrate the frequency tuning by using slug tuner, power transmission and reflection with low input power, and pulsed high power transmission with cooling channels. In this presentation, we show the design and fabrication criteria for the high power, ~ 10 kW, re-buncher and its test results.
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WEPMN034	Electron Emission from Surface Roughness on Cavity in Low Temperature	3003
	H. Kim, H.J. Cha, S. Choi, W.K. Kimpresenter, G.-T. Park IBS, Daejeon, Republic of Korea Y. Chang Hanshin University, Kyungki, Republic of Korea
	Electron emission phenomenon from surface roughness on cavity is investigated. The distribution of the electric field from the surface roughness can be obtained on cavity surface. The field emission is calculated from the electric field distribution. The generalized electron emission from electric field and temperature effect is also calculated on the surface roughness of the cavity.
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WEPMN035	QWR and HWR Cryomodules for Heavy Ion Accelerator RAON	3006
	W.K. Kim, H.J. Cha, H. Kim, H.J. Kim, Y. Kim, M. Lee, G.-T. Park IBS, Daejeon, Republic of Korea
	The accelerator called RAON has five kinds of cryomodules such as QWR, HWR1, HWR2, SSR1 and SSR2. The QWR and HWR1 cryomodules are designed and fabricated. The cryomodules will be operated at 2 K and 4 K in order to operate the superconducting cavities. The static heat load of the system was analytically computed for each configuration. The functional requirement of the cryomodules and the static heat load measurement of the QWR and HWR1 cryomodules are presented in this research.
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WEPMN036	Design Study on a High Power RF Amplifier for the RFQ*	3009
	M.-H. Chun, K.-H. Park, I.H. Yu PAL, Pohang, Kyungbuk, Republic of Korea J. Bahng Kyungpook National University, Daegu, Republic of Korea J.G. Hong, B.S. Lee, J.W. Ok, M. Won Korea Basic Science Institute, Busan, Republic of Korea D.S. Kim, Y. Moon, M. Seo Dawonsys, Siheung-City, Republic of Korea Y.S. Lee SKKU, Suwon, Republic of Korea
	Funding: Korea Basic Science Institute in Korea The design of RF amplifier of 100 kW (CW) at 165MHz is studied for a Radio Frequency Quadruple (RFQ). The RFQ as a linear accelerator is used for acceleration of low energy beam to 500 keV/u at KBSI [1]. An RF amplifier is composed of a drive, an intermediate, and a final amplifier stage with power supplies. The intermediate amplifier (IPA) of 5 kW is designed with solid state amplifier modules, and the final amplifier is designed with a tetrode tube. The high voltage power supply for the tetrode provides the fine regulation of 15 kV at 10 A. The RF amplifier is operated by program logic controller (PLC) with interlocks, and a low level RF control for RFQ accelerator. This paper describes the present design study on the 100 kW RF amplifier. "*" Supported by Korea Basic Science Institute in Korea
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WEPMN037	High Power Klystron Amplifiers for the PLS & PLS-II Storage Ring	3012
	M.-H. Chun, Y.D. Joo, H.J. Park, I.S. Park, Y.U. Sohn, I.H. Yu PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: Ministry of Science, ICT and Future Planning in Korea The RF system of the Pohang Light Source-II (PLS-II) storage ring is operating at the 3.0 GeV/340 mA with three superconducting RF cavities. PLS-II RF system was upgraded to 3.0 GeV/400 mA (max.) beam storage from 2.5 GeV/ 200 mA of PLS. Each high power RF (HPRF) station is composed of a 300 kW klystron with power supplies, transmission components including a 350 kW circulator and load, and water cooling system. The klystrons are generally operated as a RF power source with high gain amplification for RF system of light sources. This paper describes the present operation status of 300 kW klystron amplifier and experiences of the former PLS 75 kW klystron amplifiers as well as RF system. *Supported by the Ministry of Science, ICT and Future Planning in Korea
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WEPMN039	RF Accelerating Voltage of PLS-II Superconducting RF System for Stable Top-up Operation with Beam Current of 400 mA	3015
	Y.D. Joo, M.-H. Chun, T. Ha, I. Hwang, B.-J. Lee, I.S. Park, S. Shin, Y.U. Sohn, I.H. Yu PAL, Pohang, Kyungbuk, Republic of Korea
	During the beam store test up to 400 mA in the storage ring, it was observed that the vacuum pressure around the RF window of the superconducting cavity rapidly increases over the interlock level limiting the availability of the maximum beam current storing. We investigated the cause of the window vacuum pressure increment by studying the changes in the electric field distribution at the superconducting cavity and waveguide according to the beam current. An equivalent physical modeling was developed using a finite-difference time-domain (FDTD) simulation and it revealed that the electric field amplitude at the RF window is exponentially increased as the beam current increases, thus this high electric field amplitude causes a RF breakdown at the RF window.
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WEPMN041	Technical Overview of Bunch Compressor System for PAL XFEL	3018
	H.-G. Lee, Y.-G. Jung, H.-S. Kang, D.E. Kim, K.W. Kim, S.B. Lee, D.H. Na, B.G. Oh, K.-H. Park, H.S. Suh, Y.J. Suh PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) is developing a SASE X-ray Free Electron Laser based on 10 GeV linear accelerator. Bunch compressor (BC) systems are developed to be used for the linear accelerator tunnel. It consists of three hard X-ray line and one soft X-ray line. BC systems are composed of four dipole magnets, three quadrupole magnet, BPM and collimator. The support system is based on an asymmetric four-dipole magnet chicane in which asymmetry can be optimized. This flexibility is achieved by allowing the middle two dipole magnets to move transversely. In this paper, we describe the design of the stages used for precise movement of the bunch compressor magnets and associated diagnostics components.
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WEPMN042	400 mA Beam Store with Superconducting RF Cavities at PLS-II	3021
	Y.U. Sohn, M.-H. Chun, T. Ha, M.S. Hong, Y.D. Joo, H.-S. Kang, H.-G. Kim, K.R. Kim, T.-Y. Lee, C.D. Park, H.J. Park, I.S. Park, S. Shin, I.H. Yu, J.C. Yun PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: Minister of Science, ICT and Future Planning Three superconducting RF cavities were commissioned with electron beam in way of one by one during the last 3 years, and now PLS-II is in user service on the way of beam current to 400mA, the target of PLS-II. The cavities and cryomodules were prepared with SRF standard technology and procedures, then vertical test, windows conditioning, cryogenic test in each cryomodule, horizontal power test, conditioning, and commissioning without and with beam at PLS-II tunnel by collaboration with industries. All the cavities showed stable performances as good as not-observing any RF instability from cavities, couplers and windows up to 400 mA beam store, but observing several cavity quenches and minor vacuum bursts by abrupt power with control and human errors. The initial beam current for user run were recorded as 150 mA with one cavity, 280 mA with two cavities and 320 mA with three cavities. The 400 mA beam was also achieved with two cavities by decay mode and also with three cavities by top-up mode. The stabilities of RF amplitude and phase are good enough not to induce beam instabilities.
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WEPMN043	The RF Stability of PLS-II Storage Ring RF System	3024
	I.H. Yu, M.-H. Chun, M.H. Jeong, Y.D. Joo, H.-S. Kang, H.-G. Kim, H.J. Park, I.S. Park, Y.U. Sohn PAL, Pohang, Kyungbuk, Republic of Korea Y.S. Lee SKKU, Suwon, Republic of Korea
	Funding: Minister of Science, ICT and Future Planing The RF system for the Pohang Light Source (PLS) storage ring was greatly upgraded for PLS-II project of 400mA, 3.0GeV from 200mA, 2.5GeV. Three superconducting RF cavities with each 300kW maximum klystron amplifier were commissioned with electron beam in way of one by one during the last 3 years for beam current of 400mA to until March 2014. The RF system is designed to provide stable beam through precise RF phase and amplitude requirements to be less than 0.3% in amplitude and 0.3° in phase deviations. This paper describes the RF system configuration, design details and test results.
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WEPMN045	IOT Use as a Power Source for a Linear Accelerating Structure	3027
	E.A. Savin, S.V. Matsievskiy, N.P. Sobenin, I.D. Sokolov MEPhI, Moscow, Russia A.A. Zavadtsev Nano, Moscow, Russia
	Nowadays the interest of using compact and high efficiency power sources called Inductive Output Tubes (IOT) [1] for feeding accelerating structures with the required pulsed power around 1MW is increasing. In this article results of the beam dynamics and geometry calculations for the L-band IOT S-band IOT and accelerator-generator hybrid module are presented. Different concepts of the cavity have been proposed, but the most efficient has been chosen. The layout of the generator cell with biperiodic bunсher cells has been investigated. The hybrid structure composed from the generator cell and the compact SW accelerating section is proposed. IOT, linear accelerator, power supply, klystrons
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WEPMN046	Compassion of Higher Order Modes Damping Techniques for Superconducting 9-Cell Structure	3030
	Ya.V. Shashkov, A.A. Mitrofanov, N.P. Sobenin MEPhI, Moscow, Russia V. Zvyagintsev TRIUMF, Vancouver, Canada
	Funding: Work supported by Ministry of Education and Science grant 3.245.2014/r Modern types of accelerators, such as Energy recovery linacs, require low values of higher order modes (HOM) Qext. In accelerators with high current HOM could lead to high losses for the modes excitation, beam instability and beam break up. HOM couplers and waveguides are often used in such structures for HOM damping. Unfortunately they could lead to a violation of the axial symmetry of the accelerating field and negatively affect the beam emittance. Also these devices are subject for multipactor discharge and could be difficult in maintaining and fabrication. In this paper we examine several ways of HOM damping with ridged, fluted and corrugated drift tubes which are devoid of the above-mentioned drawbacks. The influence of the parameters of the drift tube on the HOM damping and on the parameters of the fundamental wave were analyzed. Higher order modes, ERL, SRF
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WEPMN047	Suppression of Higher Order Modes in an Array of Cavities Using Waveguides	3033
	Ya.V. Shashkov, N.P. Sobenin MEPhI, Moscow, Russia M. Zobov INFN/LNF, Frascati (Roma), Italy
	Funding: Work is supported by Ministry of Education and Science grant 3.245.2014/r и and by the EU FP7 HiLumi LHC - Grant Agreement 284404 In the frameworks of the High Luminosity LHC upgrade program an application of additional harmonic cavities operating at multiplies of the main RF system frequency of 400 MHz is currently under discussion. A structure consisting of two 800 MHz single cell superconducting cavities with grooved beam pipes coupled by drift tubes has been suggested for implementation. However, it is desirable to increase the number of single cells installed in one cryomodule in order to decrease the number of transitions between “warm” and “cold” parts of the collider vacuum chamber. Unfortunately it can lead to the appearance of higher order modes (HOM) trapped between the cavities. In order to solve this problem the methods of HOM damping with rectangular waveguides connected to the drift tubes were investigated and compared. In this paper we describe the results obtained for arrays of 2, 4 and 8 cavities.
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WEPMN049	Calibration of the Acceleration Voltage of Six Normal Conducting Cavities at ALBA	3036
	B. Bravo, U. Iriso, J. Marcos, J.R. Ocampo, F. Pérez, A. Salom, P. Solans ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3Gev synchrotron light source located in Barcelona and operating with users since May 2012. The ALBA storage ring uses six room temperature cavities; each one fed by two 80kW IOTs amplifiers at 499.654 MHz. An accurate calibration of the RF voltage is required for the right adjustment of the beam synchronous phase. In addition, if the ring accommodates several RF cavities, these may not be optimally phased with respect to each other, complicating the calculation of the total RF voltage. In this paper, the steps to calibrate the accelerating voltage of the SR cavities will be presented and different methodologies to cross-check these calibrations.
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WEPMN050	A Pinger Magnet System for the ALBA Synchrotron Light Source	3039
	M. Pont, N. Ayala, G. Benedetti, M. Carlà, Z. Martí, R. Núñez-Prieto ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	A pinger magnet system consisting of two short kickers, one for each transversal plane, has been recently commissioned at the ALBA Synchrotron Light Source. The kickers can excite large betatron oscillations on the electron beam in order to probe the linear and non-linear beam dynamics regime together with the turn-by turn capabilities of the BPMs. The kickers are mounted in a single Ti coated ceramic vacuum chamber, have a length of 0.3 m each and provide a half sine pulse with a pulse length of 1 μs at an amplitude of 1.4 mrad and the pulser unit is based on solid state technology. This report summarises the steps followed from its design until its installation, electric and magnetic characterisation in the laboratory, and the first results with beam.
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WEPMN051	Design of a Superconducting Gantry Cryostat	3043
	C. Bonțoiu, I. Martel, J. Sanchez-Segovia University of Huelva, Huelva, Spain R. Berjillos, J.P.B. Perez TTI, Santander, Spain
	The University of Huelva in collaboration with the Andalusian Foundation for Health Research (FABIS) and the TTI Company is currently involved in developing and assembling a prototype for a compact superconducting proton gantry with the goal to generate a business case within the narrow niche of hadron therapy. This article presents the current status of the engineering design for the cryostat and beam steering system. An account for the mechanical deformations due to magnetic forces and weight is also presented.
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WEPMN052	A New RF Laboratory for Developing Accelerator Cavities at the University of Huelva	3046
	I. Martel, C. Bonțoiu, J.A. Dueñas, D. Gordo-Yáñez, A.K. Orduz, J. Sanchez-Segovia University of Huelva, Huelva, Spain
	The University of Huelva is presently involved in R&D projects for developing RF accelerator cavities. Two types of cavities are presently under design, a prototype of room temperature RFQ injector and a quarter-wave resonator for high intensity heavy-ion linear accelerators. The laboratory is equipped with dedicated test-bench for RF measurements, which includes high-power RF generators, network analyzer, amplifiers and power meters. A clean room is also available having a dedicated space for high-precision mechanical metrology and cavity mounting, together with a vertical cryostat for superconducting cavity test.
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WEPMN055	RAMI Optimization-Oriented Design For The LIPAc RF Power System	3048
	M. Weber, J.M. Arroyo, A. Ibarra, I. Kirpitchev, J. Mollá, P. Méndez, D. Regidorpresenter, C. de la Morena CIEMAT, Madrid, Spain
	Funding: This work has been funded by the Spanish Ministry of Economy and Competitiveness. The Linear IFMIF Prototype Accelerator (LIPAc) is currently under construction in Rokkasho (Japan). LIPAc will generate a CW 9 MeV deuteron beam at 125 mA. It will serve to validate the final IFMIF accelerator concept and technologies. The RF power system is being integrated by CIEMAT (Spain) in collaboration with its partner companies and European institutes. LIPAc RF Power System design has been performed aiming high reliability, high availability and easy maintainability to address one of the most important requirements for IFMIF. The target of LIPAc tests is to validate the technologies and designs for the final phase of IFMIF. Several improvements in reliability, availability and maintainability have been implemented in the LIPAc RF power System. These improvements are based on both, new technologies and new maintenance philosophy. The results of their first tests are shown in this paper. Additional potential improvements are also analyzed.
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WEPMN056	High Power Testing of the First Re-buncher Cavity for LIPAC	3051
	F. Toral, D. Gavela, I. Podadera, D. Regidor, M. Weber, C. de la Morena CIEMAT, Madrid, Spain B. Bravo, R. Fos, J.R. Ocampo, F. Pérez, A. Salom, P. Solans ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	Funding: This work is partially supported by the Spanish Ministry of Economy and Competitiveness under projects AIC-A-2011-0654 and the Agreement as published in BOE, 16/01/2013, page 1988 Two re-buncher cavities will be installed at the Medium Energy Beam Transport (MEBT) of the LIPAc accelerator, presently being built at Rokkasho (Japan). They are IH-type cavities with 5 gaps and will provide an effective voltage of 350 kV at 175 MHz for deuterons at 5 MeV. The first prototype has been designed at CIEMAT and built by the Spanish industry. The high power tests and RF conditioning have been successfully performed at the ALBA/CELLS RF laboratory. A solid state power amplifier, which has been developed by CIEMAT and its partner companies at Spain for the LIPAc RF System, has been used for the tests. The cavity has shown a performance according to calculations, regarding the dissipated power, peak temperatures and coupling factor. RF conditioning was started with a duty cycle of 3%, which was increased gradually till continuous wave (CW), which is the nominal working mode in LIPAc.
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WEPMN057	Calculation and Design of a RF Cavity for a Novel Compact Superconducting Cyclotron for Radioisotope Production	3055
	D. Gavela, J. Calero, L. García-Tabarés, A. Guirao, D. Obradors-Campos, C. Oliver, J.M. Pérez Morales, I. Podadera, F. Toralpresenter CIEMAT, Madrid, Spain
	Funding: Work partially funded by CDTI and the Spanish Ministry of Economy and Competitiveness, under the subprogram CENIT, project AMIT, reference CEN-20101014 The AMIT cyclotron will be a 8.5 MeV, 10 microAmp, CW, H− accelerator for the purpose of radioisotope production. It includes a superconducting, weak focusing, 4 T magnet, which allows for a low extraction radius and a compact design. The RF cavity design has to deal with challenging requirements: high electric fields created by the required accelerating voltage (60 kV – 70 kV) on a small gap, a small aperture of the magnet leading to high capacitances and thermal losses, and a requirement for a low overall size of the cavity. A quarter wave resonator with one dee (two acceleration gaps) design was chosen. Calculations with HFSS have been performed to compute the resonant frequency, tuners sensitivity, S-parameters, power losses and geometry for input coupler and pickup. A structural Ansys model has been used to analyze the stresses and the deformations of the cavity. A thermal Ansys model was used for the design of the cooling circuits and the calculation of the temperature distribution. Finally, the fluid dynamics of the cooling circuits have been carefully studied. The results of these calculations and the consequent design decisions are presented in this paper.
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WEPMN058	Transverse Impedance Measurements and DC Breakdown Tests on the First Stripline Kicker Prototype for the CLIC Damping Rings	3058
	C. Belver-Aguilar, A. Faus-Golfepresenter IFIC, Valencia, Spain M.J. Barnes, H.A. Day CERN, Geneva, Switzerland A. Faus-Golfepresenter LAL, Orsay, France F. Toral CIEMAT, Madrid, Spain
	A first stripline kicker prototype for beam extraction from the CLIC Damping Rings (DRs) has been designed at IFIC and CIEMAT, with excellent field homogeneity, good power transmission and low beam coupling impedance. The prototype has been built by the company Trinos Va\-cuum Projects, and laboratory tests and measurements have been carried out at CERN to characterize, without beam, the electromagnetic response of the striplines. In this paper, we present the measurements of the transverse beam coupling impedance, using the coaxial wire method, and a comparison with simulations. Furthermore, results of DC breakdown tests, using High Vol\-ta\-ge (HV) power supplies, are also reported.
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WEPMN059	Design Study and Construction of a Transverse Beam Halo Collimation System for ATF2	3062
	N. Fuster-Martínez, A. Faus-Golfe IFIC, Valencia, Spain P. Bambade, S. Liu, S. Wallon LAL, Orsay, France K. Kubo, T. Okugi, T. Tauchi, N. Terunuma KEK, Ibaraki, Japan I. Podadera, F. Toral CIEMAT, Madrid, Spain
	Funding: Work supported by IDC-20121074, FPA2013-47883-C2-1-P and ANR-11-IDEX-0003-02 The feasibility and efficiency of a transverse beam halo collimation system for reducing the background in the ATF2 beamline has been studied in simulations. In this paper the design and construction of a retractable transverse beam halo collimator device is presented. The wakefield induced-impact of a realistic mechanical prototype has been studied with CST PS, as well as the wakefield beam dynamics impact by using the tracking code PLACET.
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WEPMN061	ESS PLC Controls Strategy	3066
	D.P. Piso, P. Arnold, S.L. Birch, T. Gahl, T. Korhonen, A. Nordt, J.G. Weisend ESS, Lund, Sweden
	The European Spallation Source ESS AB is an accelerator-driven neutron spallation source. The Integrated Controls System (ICS) division is responsible for providing controls and monitoring for all parts of the machine (accelerator, target, neutron scattering systems and conventional facilities). Also, Accelerator Division, Target Division and other parts of the organisation will be deploying PLC Automation Systems. A large number of applications have been identified across all the facility where PLCs will be used: cryogenics, vacuum, water-cooling, fluid systems, power systems, and safety \& protection systems. This work describes the different activities put in place and proposes the strategy followed at ESS regarding PLC technologies. This strategy consists not only of the standardisation of a PLC vendor but also testing activities, generation of documentation and standardization of other aspects (for instance, regarding installation). The documentation about PLC controls integration and standardisation and the approach to insert PLCs in the different controls workflows are described. Finally, the results of different tests (PLC timing correlation) are shown.
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WEPMN062	MAX IV 3 GeV Storage Ring Magnet Block Production Series Measurement Results	3069
	M.A.G. Johansson, L.-J. Lindgren, M. Sjöström, P.F. Tavares MAX-lab, Lund, Sweden
	The magnet design of the MAX IV 3 GeV storage ring replaces the conventional support girder + discrete magnets scheme of previous third-generation synchrotron radiation light sources with a compact (Ø25 mm aperture) integrated design having several consecutive magnet elements precision-machined out of a common solid iron block, with mechanical tolerances of ±0.02 mm over the 2.3–3.4 m block length. The production series of 140 integrated magnet block units, which was totally outsourced to industry, was completed mid-2014, with mechanical/magnetic QA conforming to specifications. This article presents mechanical and magnetic field measurement results of the full production series.
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WEPMN065	Progress at the FREIA Laboratory	3072
	M. Olvegård, A.K. Bhattacharyya, T.J.C. Ekelöf, J. Eriksson, K. Fransson, K.J. Gajewski, V.A. Goryashko, L. Hermansson, M. Holz, M. Jacewicz, M. Jobs, Å. Jönsson, H. Li, T. Lofnes, H. Nicander, R.J.M.Y. Ruber, R. Santiago Kern, R. Wedberg, V.G. Ziemann Uppsala University, Uppsala, Sweden D.S. Dancila, A. Rydberg Uppsala University, Department of Engineering Sciences, Uppsala, Sweden R.A. Yogi ESS, Lund, Sweden
	The FREIA Facility for Research Instrumentation and Accelerator Development at Uppsala University, Sweden, has reached the stage where the testing of superconducting cavities for the European Spallation Source (ESS) is starting. The new helium liquefaction plant has been commissioned and now supplies a custom-made, versatile horizontal cryostat, HNOSS, with liquid helium at up to 140 l/h. The cryostat has been designed and built to house up to two accelerating cavities, or, later on, other superconducting equipment such as magnets or crab cavities. A prototype cavity for the spoke section of the ESS linac will arrive mid 2015 for high-power testing in the horizontal cryostat. Two tetrode-based commercial RF power stations will deliver 400 kW peak power each, at 352 MHz, to the cavity through an RF distribution line developed at FREIA. In addition, significant progress has been made with in-house development of solid state amplifier modules and power combiners for future use in particle accelerators. We report here on these and other ongoing activities at the FREIA laboratory.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN065
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WEPMN066	Hall Probe Measurements of 80 Unit Cell Magnets for the MAX-IV Storage Ring	3076
	A.A.F. Ahl Scanditronix Magnet AB, Vislanda, Sweden
	80 unit cell magnet segments have been manufactured by Scanditronix Magnet for the 3 GeV storage ring at MAX-IV in Lund, Sweden. All of the magnets have been approved by Max-lab after a large field measuring campaign using both a high precision hall probe bench, as well as a new rotating coil system. Each unit cell magnet consists of one dipole, two quadrupole, three sextupole and one vertical and one horizontal corrector magnets. The hall probe bench was used to measure the dipole magnet (with combined dipole and quadrupole component) as well as the quadrupole magnets. This poster will focus on the hall probe measurements performed on the dipole magnets from the perspective of a manufacturer. E.g. the repeatability of the measurements and the relation between field performance and mechanical tolerances will be analyzed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN066
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WEPMN067	Upgrade of the TCDQ Diluters for the LHC Beam Dump System	3079
	M.G. Atanasov, W. Bartmann, J. Borburgh, C. Boucly, C. Bracco, L. Gentini, B. Moles, W.J.M. Weterings CERN, Geneva, Switzerland
	The TCDQ diluters are installed as part of the LHC beam dump system to protect the Q4 quadrupole and other downstream elements during a beam dump that is not synchronised with the abort gap, or in case of erratic firing of the extraction kickers. These diluter elements installed during Run 1 were compatible with beam up to 60 % of the nominal intensity, which was insufficient for the second run of the LHC. This paper describes the requirements for the upgrade done during the First Long Shutdown (LS1), to make the TCDQ compatible with the full 7 TeV LHC beam at intensities required for the future runs of the machine. Subsequently the mechanical design changes, implementation and commissioning of the TCDQ are reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN067
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WEPMN068	Upgrade of the CERN SPS Extraction Protection Elements TPS	3083
	J. Borburgh, B. Balhan, M.J. Barnes, C. Baud, M.A. Fraser, V. Kain, F.L. Maciariello, G.E. Steele, F.M. Velotti CERN, Geneva, Switzerland
	In 2006 the protection devices upstream of the septa in both extraction channels of the CERN SPS to the LHC were installed. Since then, new beam parameters have been proposed for the SPS beam towards the LHC in the framework of the LIU project. The mechanical parameters and assumptions on which these protection devices presently have been based, need validation before the new upgraded versions can be designed and constructed. The paper describes the design assumptions for the present protection device and the testing program for the TPSG4 at HiRadMat to validate them. Finally the requirements and the options to upgrade both extraction protection elements in the SPS are described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN068
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WEPMN070	Measurement Techniques and Application of Combined Parallel/Orthogonal Magnetic Bias on a Ferrite Tuned Resonator in Low Frequency Range (3-10 MHz)	3087
	G. Favia, F. Casperspresenter, M. Morvillo, C. Rossi, C. Vollinger CERN, Geneva, Switzerland
	We present several measurement methods for evaluation of magnetic properties of magnetically biased and non-biased ferrite samples in a coaxial test fixture. One important aspect is the crosscheck of results obtained by using different and independent measurement and evaluation methods. Since a rather high DC bias current has to be applied, a dedicated network was designed that allows the passage of up to 50 A DC without degradation of the RF performance. With a combination of calibration methods and a compensating topology with two identical sample holders, a good performance was achieved. In this context, magnetic material parameters for about 10 different types of ferrite were obtained. The orthogonal magnetic bias was added by placing the entire test fixture into a large toroidal coil. Thus, the bias field can be supplied independently from, and in addition to the classical parallel bias. An optimal combination between the two biasing fields was found, resulting in a reduction of magnetic losses up to 50% on certain ferrites. We show that the mixed magnetization, normally used for garnets only, is beneficial also for other types of ferrites.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN070
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WEPMN071	Enhanced Diagnostic Systems for the Supervision of the Superconducting Circuits of the LHC	3090
	R. Denz, Z. Charifoulline, K. Dahlerup-Petersen, A.P. Siemko, J. Steckert CERN, Geneva, Switzerland
	Being an integral part of the protection system for the superconducting circuits of the LHC, the data acquisition systems used for the circuit supervision underwent a substantial upgrade during the first long shutdown of the LHC. The sampling rates and resolution of most of the acquired signals increased significantly. Newly added measurements channels like for the supervision of the quench heater circuits of the LHC main dipoles allow identifying specific fault states. All LHC main circuits are meanwhile equipped with earth voltage feelers allowing monitoring the electrical insulation strength, especially during the fast discharges. The protection system for the bus-bar splices is now capable to operate in different modes. By this measure, it is possible fulfilling the requirements for different specific tests like the warm bus-bar measurements and current stabilizer continuity measurements (CSCM) without field interventions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN071
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WEPMN072	Status and Planned Experiments of the Hiradmat Pulsed Beam Material Test Facility at CERN SPS	3093
	A. Fabich, N. Charitonidis, I. Efthymiopoulos, M. Meddahi CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	Funding: EuCARD-2 is co-funded by the partners and the European Commission under Capacities 7th Framework Programme, Grant Agreement 312453. HiRadMat (High Irradiation to Materials) is a facility at CERN designed to provide high-intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies (e.g. vacuum windows, shock tests on high power targets, collimators) can be tested. The beam parameters (SPS 440 GeV protons with a pulse energy of up to 3.4 MJ, or alternatively lead/argon ions at the proton equivalent energy) can be tuned to match the needs of each experiment. It is a test area designed to perform single pulse experiments to evaluate the effect of high-intensity pulsed beams on materials in a dedicated environment, excluding long-time irradiation studies. The facility is designed for a maximum number of 1016 protons per year, in order to limit the activation of the irradiated samples to acceptable levels for human intervention. This paper will demonstrate the possibilities for research using this facility and go through examples of upcoming experiments scheduled in the beam period 2015/2016.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN072
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