IPAC2016 - List of Keywords (coupling)

Paper	Title	Other Keywords	Page
MOYBA01	Limits and Possibilities of Laser Wakefield Accelerators	electron, laser, plasma, focusing	16
	W. Leemans LBNL, Berkeley, California, USA
	This presentation provides an outlook into the future of laser-driven plasma wakefield accelerators. What has been achieved, what more is possible and what are the limits.
	Slides MOYBA01 [43.465 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOYBA01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOYCA01	Review of Linear Optics Measurements and Corrections in Accelerators	optics, quadrupole, collider, betatron	20
	R. Tomás CERN, Geneva, Switzerland M. Aiba PSI, Villigen PSI, Switzerland A. Franchi ESRF, Grenoble, France U. Iriso ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The measurement and correction of optics parameters has been a major concern since the advent of strong focusing synchrotron accelerators. Traditionally, colliders have led the development of methods for optics control based on turn-by-turn centroid data, while lepton storage rings have focused on closed orbit response techniques. Recently considerable efforts are being invested in comparing these techniques in different light sources and colliders. An emerging class of less invasive optics control techniques based on the optimization of performance related observables is demonstrating a great potential. A review of the existing techniques is presented highlighting comparisons, merits and limitations.
	Slides MOYCA01 [4.184 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOYCA01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOOCA01	R&D of a Super-compact SLED System at SLAC	cavity, operation, impedance, FEL	39
	J.W. Wang, G.B. Bowden, S. Condamoor, Y. Ding, V.A. Dolgashev, J.P. Eichner, M.A. Franzi, A.A. Haase, P. Krejcik, J.R. Lewandowski, S.G. Tantawi, L. Xiao, C. Xu SLAC, Menlo Park, California, USA
	Funding: Work supported by Department of Energy contract DE-AC03-76SF00515. We have successfully designed, fabricated, installed and tested a super-compact X-Band SLED system at SLAC. It is composed of an elegant mode converter/polarizer and a single sphere energy store cavity with high Q of 94000 and diameter less than 12 cm. The available RF peak power of 50 MW can be compressed to peak average power of more than 200 MW in order to double the kick for the electron bunches in a RF transverse deflector system and greatly improve the measurement resolution for both the electron bunch and the x-ray FEL pulse. High power operation has demonstrated the excellent performance of this RF compression system without any problems in RF breakdown, pulse heating and radiation. The design physics and fabrication as well as the measurement results will be presented in detail.
	Slides MOOCA01 [20.278 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOOCA01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB008	Modeling and Experimental Studies of Beam Halo at ATF2	vacuum, scattering, damping, optics	88
	R.J. Yang, P. Bambade, V. Kubytskyi LAL, Orsay, France A. Faus-Golfe, N. Fuster-Martínez IFIC, Valencia, Spain T. Naito KEK, Ibaraki, Japan
	The Accelerator Test Facility 2 (ATF2) at KEK is a prototype of the final focus system for the next generation of Future Linear Colliders(FCL). It aims to focus the beams to tens of nanometer transverse sizes and to provide stability at the few nm level. Achieving these goals requires modelling, measuring and suppressing of the transverse beam halo before the interaction point (IP). This paper presents a beam tail/halo generator based on realistic model and the investigation of vertical and horizontal beam tail/halo distribution at ATF2.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB008
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB011	ROSE, Measuring the Full 4D Transverse Beam Matrix of Ion Beams	emittance, ion, vacuum, detector	98
	M.T. Maier, X. Du, P. Gerhard, L. Groening, S. Mickat, H. Vormann, C. Xiao GSI, Darmstadt, Germany
	A ROtating System for Emittance measurements ROSE, to measure the full 4 dimensional transverse beam matrix of an ion beam has been developed and commissioned. Different ion beams behind the HLI at GSI have been used in two commissioning beam times. All technical aspects of ROSE have been tested, ROSE has been benchmarked against existing emittance scanners for horizontal and vertical projections, and the method, hard-, and software to measure the 4D beam matrix has been upgraded, refined, and successfully commissioned. The inter plane correlations of the HLI beam have been measured, yet as no significant initial correlations were found to be present, controlled coupling of the beam by using a skew triplet has been applied and confirmed with ROSE. The next step is to use ROSE to measure and remove the known inter plane correlations of a uranium beam before SIS18 injection.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB025	The Development of 16-Electrode Monitor for Measurement of the Multipole-Moment	quadrupole, injection, impedance, proton	140
	Y. Nakanishi, A. Ichikawa, A. Minamino, K.G. Nakamura, T. Nakaya Kyoto University, Kyoto, Japan T. Koseki, H. Kuboki KEK, Tokai, Ibaraki, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Funding: This work was supported by MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled 'Unification and　Development of the Neutrino Science Frontier' In the J-PARC main ring, the beam intensity is greatly increased to 750 kW or more in near future. Even the beam intensity become higher, the beam loss must be kept at the same level as present. Aiming to make the cause of beam loss clear, we have been developing the beam monitor to measure the beam size. The quadrupole moment is related to the beam size. In principle, monitors with more than four electrodes can measure the quadrupole moment. In addition, two monitors located at the places with different beta functions can measure the emittances and beam sizes, providing the horizontal and vertical beta functions. To obtain more precise quadrupole moment and higher multipoles, we are developing the multi-electrode monitor, tentatively, with 16 electrodes. As a reference of 16-electrode monitor, two 4-electrode BPMs are investigated to measure quadrupole moments. We will present the measurement result of 4-electrode monitors and the status of the development of the 32-electrode monitor.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB025
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB038	Development of Shoebox BPM for Xi‘an Proton Application Facility	simulation, proton, impedance, closed-orbit	175
	W. Wang, X. Guan, W.-H. Huang, X.W. Wang, Z. Yang, H.Y. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China M.T. Qiu, Z.M. Wang State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Shannxi, People's Republic of China
	In this paper, development of the Shoebox BPM is presented which can be applied for the measurement of turn-by-turn position data, closed orbit and tune of Xi'an Proton Application Facility (XiPAF). The preliminary design of the physical dimensions including the electrode aperture, the pipe aperture and the gap between the two electrodes is performed by calculating their effects on BPM response respectively with the equivalent circuit model. Furthermore, the mechanical structure of the Shoebox BPM is optimized by CST simulation to achieve better performance. The dependency of the BPM sensitivity and zero offset on the frequency is diminished by adding one isolating ring, which decreases coupling capacitance of electrodes and compensates ground capacitance difference of the two electrodes. Finally one prototype of the Shoebox BPM has been fabricated and tested offline. Results show that relative position measurement error due to frequency dependency of sensitivity is less than 1% and absolute measurement error due to frequency dependency of zero offset is expected to be less than 0.1 mm.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB038
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMB051	Cavity BPM Performance Online Evaluation using PCA Method	cavity, experiment, electron, factory	208
	Y.B. Leng, L.W. Lai, L.Y. Yu, R.X. Yuan SSRF, Shanghai, People's Republic of China J. Chen, Z.C. Chen SINAP, Shanghai, People's Republic of China
	Funding: NSFS 11575282 This article proposes a new test method to evaluate the performance of cavity beam position monitors using the actual beam as the exciting signal. The new method sepa-rates the signals of different modes and improves the measurement accuracy by eliminating unwanted cou-plings from other sources.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB051
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMR029	Experience with DOROS BPMs for Coupling Measurement and Correction	dipole, electronics, controls, injection	303
	T. Persson, J.M. Coello de Portugal, A. Garcia-Tabares, M. Gąsior, A. Langner, T. Lefèvre, E.H. Maclean, L. Malina, J. Olexa, P.K. Skowroński, R. Tomás CERN, Geneva, Switzerland J. Olexa STU, Bratislava, Slovak Republic
	The Diode ORbit and OScillation System (DOROS) system is designed to provide accurate measurements of the beam position in the LHC. The oscillation part of the system, which is able to provide turn-by-turn data, is used to measure the transverse coupling. Since the system provides high resolution measurements for many turns only small excitations are needed to accurately measure the transverse coupling. In this article we present the performance the system to measure coupling and compare it to the BPMs not equipped with this system.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR029
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMR037	Analysis of Asymmetry Tolerances and Cross-coupling in Cavity BPMs	cavity, alignment, simulation, dipole	331
	E. Yamakawa, S.T. Boogert, A. Lyapin, L.J. Nevay JAI, Egham, Surrey, United Kingdom S. Syme FMB Oxford, Oxford, United Kingdom
	Geometric asymmetries in cavity BPMs result in a coupling between horizontal and vertical signals, which complicates their usage and may affect both the dynamic range and spatial resolution of the system in both directions. Tolerances to several types of geometric asymmetries have been analysed using a 3D electromagnetic field solver (GdfidL). We report on some of the results and discussed the possible impact of the considered geometrical distortions.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR037
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMR060	C-Band Deflecting Cavity for Bunch Length Measurement of 2.5 MeV Electron Beam	cavity, vacuum, electromagnetic-fields, simulation	386
	J. Jiang, H.B. Chen, J. Shi, P. Wang, L. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China
	The C-band deflecting cavity designed last year is finished. In this paper, the RF measurement of the cavity is introduced. After tuning, it works well at 5.712GHz with a coupling factor degree around 1.05. And we measured the electromagnetic field with bead-pull method. The flatness of the magnetic field is around 0.9, which is not ideal but meet the requirements of the bunch length measurement. And we propose a method of tuning to make sure both frequency and field flatness.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR060
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMW002	Modeling and Simulation of Broadband RF Cavities in PSpice	cavity, simulation, impedance, storage-ring	392
	J. Harzheim, D. Domont-Yankulova, H. Klingbeil, R. Königstein TEMF, TU Darmstadt, Darmstadt, Germany M. Frey, H. Klingbeil GSI, Darmstadt, Germany
	Barrier bucket systems are planned for the SIS100 Synchrotron (part of the future accelerator facility FAIR) and the ESR storage ring to facilitate several longitudinal beam manipulations [9] [15]. In order to achieve a single-sine gap signal of the desired amplitude and quality, effects in the linear and nonlinear region of the RF systems have to be investigated and included in the design of the overall system. Therefore, the cavities and the amplifier stages are to be modeled in PSpice. In this contribution, a cavity model will be presented. In a first step, a model for the magnetic alloy (MA) ring cores, which highly account for the properties of the cavity, has been found based on measurement data. In a second step, the future setup of the cavity is systematically created using the MA ring core models. The model of the cavity allows simulations in frequency domain as well as time domain. The results show good agreement with former measurements.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW002
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMW003	Thermal Simulation of an Energy Feedback Normal Conducting RF Cavity	cavity, simulation, operation, electron	396
	M. Fakhari, K. Flöttmann, S. Pfeiffer, H. Schlarb DESY, Hamburg, Germany J. Roßbach University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany A. Yahaghi CFEL, Hamburg, Germany
	Thermal simulation has been performed for an energy feedback normal conducting RF cavity. The cavity is going to be used as a fast actuator to regulate the arrival time of the electron bunches in fs level in FLASH. By measuring the arrival time jitter of one bunch in a bunch train, the designed cavity apply a correcting accelerating or decelerating voltage to the next bunches. The input power of the cavity is provided by a solid state amplifier and will be coupled to the cavity via a loop on the body. To achieve the fs level precision of the arrival time, the cavity should be able to provide accurate accelerating voltage with a precision of 300 eV. We performed thermal simulation to find out the temperature distribution of the cavity and make sure that heating will not affect its voltage precision. The simulation results show that by using two input loops the coupling constant will vary from 4.11 to 4.13 during the operation of the cavity which effect on the bunchs' arrival time would be less than 0.25 fs. While using just one input loop can lead to an error of about 1 fs.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW003
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMW005	Design of Linac with the New Gaskets Clamping Fabrication Technique	vacuum, impedance, linac, gun	403
	F. Cardelli INFN-Roma1, Rome, Italy D. Alesini INFN/LNF, Frascati (Roma), Italy M. Magi, L. Palumbo University of Rome La Sapienza, Rome, Italy F. Pellegrino, V. Pettinacci INFN-Roma, Roma, Italy
	Recently, a new technique for the realization of high gradient accelerating structures based on the use of gaskets without brazing processes, has been successfully tested at high power on a 1.6 cells RF gun (D. Alesini, et al, PRST 18, 02001, 2015). The new technique developed at the Laboratories of Frascati of the INFN (Italy) in the framework of the SPARC_LAB project has been also adopted for the ELI-NP RF gun. The use of the special gaskets that simultaneously guarantee the vacuum seal and a perfect RF contact allow to avoid the brazing process, strongly reducing the cost, the realization time and the risk of failure. Moreover, without copper annealing due to the brazing process, it is possible, in principle, to decrease the breakdown rate increasing, at the same time, the maximum achievable gradient. The extension of this new fabrication process to complex LINAC structures is the next step on the application of this new technique on particle accelerator. In the paper, we discuss how to extend this process to S-band and C-band Travelling Wave accelerating structures illustrating their electromagnetic design and their mechanical realization.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW005
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMW023	Optimization of the RF Cavity of a Low-energy Storage Ring for Thomson Scattering X-Ray Source	cavity, HOM, storage-ring, higher-order-mode	438
	L. Ovchinnikova, V.I. Shvedunov SINP MSU, Moscow, Russia A. Ryabov IHEP, Moscow Region, Russia V.I. Shvedunov LEA MSU, Moscow, Russia
	Results of optimization of the RF cavity of a low-energy storage ring for Thomson scattering X-ray source are presented. The geometry of 714 MHz RF cavity was optimized to provide maximum shunt impedance taking into account position of higher order modes (HOMs). The number and position of cooling channels were adjusted to minimize frequency shift due to cavity thermal deformations. The waveguide coupler and frequency tuner were calculated. Special attention was paid to detailed calculations of the HOMs parameter and to study of methods to minimize their influence on the storage ring beam dynamics.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW023
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMW028	Progress on the MICE RF Module at LBNL	cavity, vacuum, operation, experiment	454
	T.H. Luo, A.J. DeMello, A.R. Lambert, D. Li, T.J. Loew, S. Prestemon, S.P. Virostek, J.G. Wallig LBNL, Berkeley, California, USA T.G. Anderson, A.D. Bross, M.A. Palmer Fermilab, Batavia, Illinois, USA Y. Torun IIT, Chicago, Illinois, USA
	The international Muon Ionization Cooling Experiment aims to demonstrate the transverse cooling of a muon beam by ionization in energy absorbers. The final MICE cooling channel configuration has two RF modules, each housing a 201 MHz RF cavity used to compensate the longitudinal energy loss in the absorbers. The assembly of MICE RF Module is being carried out at LBL. In this paper we will report the recent progress on the assembly work.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW028
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMW034	Final Commissioning of the MICE RF Module Prototype with Production Couplers	cavity, vacuum, operation, Windows	474
	Y. Torun, P.G. Lane Illinois Institute of Technology, Chicago, Illlinois, USA T.G. Anderson, M. Backfish, D.L. Bowring, A. Moretti, D.V. Neuffer, D.W. Peterson, M. Popovic, K. Yonehara Fermilab, Batavia, Illinois, USA B.T. Freemire IIT, Chicago, Illinois, USA T.L. Hart UMiss, University, Mississippi, USA A.V. Kochemirovskiy University of Chicago, Chicago, Illinois, USA T.H. Luo LBNL, Berkeley, California, USA
	Funding: Supported by the US Department of Energy Office of Science through the Muon Accelerator Program. We report operational experience from the prototype RF module for the Muon Ionization Cooling Experiment (MICE) with final production couplers at Fermilab's MuCool Test Area. This is the last step in fully qualifying the RF modules for operation in the experiment at RAL.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW034
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMW038	Measurements of Copper RF Surface Resistance at Cryogenic Temperatures for Applications to X-Band and S-Band Accelerators	cavity, cryogenics, experiment, electron	487
	A.D. Cahill, A. Fukasawa, J.B. Rosenzweig UCLA, Los Angeles, California, USA G.B. Bowden, V.A. Dolgashev, M.A. Franzi, S.G. Tantawi, P.B. Welander, C. Yoneda SLAC, Menlo Park, California, USA J. Guo JLab, Newport News, Virginia, USA Y. Higashi OIST, Onna-son, Okinawa, Japan
	Funding: Funding from DOE SCGSR and DOE/SU Contract DE-AC02-76-SF00515 Recent SLAC experiments with cryogenically cooled X-Band standing wave copper accelerating cavities have shown that these structures can operate with accelerating gradients of ~250 MV/m and low breakdown rates. These results prompted us to perform systematic studies of copper rf properties at cryogenic temperatures and low rf power. We placed copper cavities into a cryostat cooled by a pulse tube cryocooler, so cavities could be cooled to 4K. We used different shapes of cavities for the X-Band and S-Band measurements. Properties of the cavities were measured using a network analyzer. We calculated rf surface resistance from measured Q0 and Q external of the cavity at temperatures from 4 K to room temperature. The results were then compared to the theory proposed by Reuter and Sondheimer. These measurements are a part of studies with the goal of reaching very high operational accelerating gradients in normal conducting rf structures.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW038
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMY005	Study of Pretuning and High Power Test of DTL Iris Waveguide Couplers Using a Single Cell Cavity	cavity, DTL, factory, simulation	522
	S.W. Lee, M.S. Champion, Y.W. Kang ORNL, Oak Ridge, Tennessee, USA
	Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S.DOE. Six drift tube linac (DTL) cavities have been operating successfully at the Spallation Neutron Source (SNS). Each cavity is fed by a tapered ridge waveguide iris input coupler and a waveguide ceramic disk window. The original couplers and cavities have been in service for more than a decade. Design optimization and tuning of the couplers were initially performed prior to installation and commissioning of the cavities. Since each DTL cavity is unique, expensive, and fully utilized for neutron production, none of the cavity structure is available as a test cavity or a spare. Maintaining spares for operations and for future system upgrade, test setup of the iris couplers for precision tuning is needed. Ideally a smaller cavity structure may be used for pretuning and RF conditioning of the iris couplers as a test cavity or a bridge waveguide. In this paper, study of using a single cell cavity for the iris tuning and conditioning is presented along with the 3D simulation results.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY005
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMY016	Quadrature Directional Coupling Method for Precise RF Power Measurement	radio-frequency, feedback, controls, experiment	549
	B. Du, G. Huang, L. Lin, Y.T. Liu, Z. Zhao USTC/NSRL, Hefei, Anhui, People's Republic of China
	The directional coupler is used in the RF transmission and distribution system of accelerator, to measure the forward and backward power. Due to the finite directional isolation of the coupler (20-30dB normally), the crosstalk exists between the bi-directional coupling output signals. For the typical isolation of 26dB, if the bi-directional crosstalk signals are in- or anti- phase, the error of input or reflected power measurement is 10% in case of total reflection, whilst the error of reflected power measurement is 100% in case of VSWR 1.1. A method of quadrature directional coupling measurement is developed to solve the isolation problem. A pair of directional couplers with 90° phase difference are employed to measure the RF power. The influence of the directional crosstalk would be reduced significantly by processing the measurement data. The prototype of quadrature directional couplers is constructed to verify this method. The results showed that the measurement accuracy of quadrature coupler pair after data process is better than 2% for forward measurement, even if the error of single coupler is over 6%. The paper also analyses the error caused by non-ideal quadrature.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY016
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMY034	The Distributed Bunch Amplifier	network, electron, focusing, distributed	573
	M.A. Franzi, A. Jensen, S.G. Tantawi, F. Toufexis, A.R. Vrielink SLAC, Menlo Park, California, USA
	The Distributed Bunch Amplifier (DBA) is a high efficiency RF source that utilizes a phase locked deflecting cavity and output circuit to produce a synchronous beam-wave interaction. The DBA improves on the design of previous embodiments of this technology, such as the Gyrocon, by implementing a modern decoupled output circuit design and conical PPM beam focusing array in order to scale to higher frequencies and efficiency than previously demonstrated. Presented is a proof-of-concept S-band, 2.856 GHz, device operating with a 60 kV, 8 Amp, electron beam. Each stage of the three-cavity decoupled output circuit is optimized based on complex amplitude and shunt impedance to achieve an electronic efficiency of greater than 90%. Initial numerical analysis of this design indicates that an overall operating efficiency of greater than 70% is feasible. Detailed simulated results of the S-band model and designs to scale this technology to higher power and frequency will be discussed. Budker, G. I., et al. "The Gyrocon: An Efficient Relativistic High Power VHF Generator." Part. Accel. 10 (1979): 41-59.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY034
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMY035	Theoretical Analysis and Simulation of a Compact Frequency Multiplier for High Power Millimeter and Terahertz Sources	cavity, electron, cathode, space-charge	576
	A.R. Vrielink, S.G. Tantawi, F. Toufexis SLAC, Menlo Park, California, USA
	As the demands on accelerating gradients and the temporal resolution of beam diagnostics and manipulation schemes grow, millimeter-wave and terahertz (THz) accelerator structures may present a natural solution. The recent advent of a radiofrequency undulator and the development of a 0.45 THz accelerator demonstrate growing interest in this frequency regime; however, growth in this area is limited by the lack of efficient, compact high power sources. We present a novel vacuum electronic device featuring an interaction between a radially bunched electron beam and azimuthally traveling waves. The use of an inward traveling radial sheet beam mitigates space charge effects at the low operating energy of 10-30 keV and allows for a high input beam current of approximately 0.5-10 A. Based on preliminary calculations, these devices could operate from 50 GHz to 250 GHz with tens of kiloWatts of output power, while the expected efficiency would scale from 60% at 80 GHz to 15% at 230 GHz. Here we present the underlying theory, possible structure design, and preliminary results from analytical calculations and simulation. Tantawi, S. et al. Phys. Rev. Lett. 112, 164802 (April, 2014) Nanni, E. et al. Nat. Commun. 6, 8486 (October, 2015)
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY035
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMY036	High-harmonic mm-Wave Frequency Multiplication using a Gyrocon-like Device	cavity, electron, vacuum, plasma	579
	F. Toufexis, V.A. Dolgashev, M.V. Fazio, A. Jensen, S.G. Tantawi, A.R. Vrielink SLAC, Menlo Park, California, USA P. Borchard Dymenso LLC, San Francisco, USA
	Funding: This project was funded by U.S. Department of Energy under Contract No. DE-AC02-76SF00515, and the National Science Foundation. Traditional linear interaction RF sources, such as Klystrons and Traveling Wave Tubes, fail to produce significant power levels at millimeter wavelengths. This is because their critical dimensions are small compared to the wavelength, and the output power scales as the square of the wavelength. We present a vacuum tube technology, where the device size is inherently larger than the operating wavelength. We designed a low–voltage mm–wave source, with an output interaction circuit based on a spherical sector cavity. This device was configured as a phased-locked frequency multiplier. We report the design and cold test results of a proof-of-principle fifth harmonic frequency multiplier with an output frequency of 57.12 GHz.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOR014	Measurements of the CERN PS Longitudinal Resistive Coupling Impedance	impedance, HOM, synchrotron, cavity	626
	M. Migliorati, N. Biancacci, H. Damerau, G. Sterbini CERN, Geneva, Switzerland M. Migliorati University of Rome "La Sapienza", Rome, Italy M. Migliorati, L. Ventura INFN-Roma1, Rome, Italy S. Persichelli University of Rome La Sapienza, Rome, Italy
	The longitudinal coupling impedance of the CERN PS has been studied in the past years in order to better understand collective effects which could produce beam intensity limitations for the LHC Injectors Upgrade project. By measuring the incoherent quadrupole synchrotron frequency vs beam intensity, the inductive impedance was evaluated and compared with the impedance model obtained by taking into account the contribution of the most important machine devices. In this paper, we present the results of the measurements performed during a dedicated campaign, of the real part of the longitudinal coupling impedance by means of the synchronous phase shift vs beam intensity. The phase shift has been measured by using two different techniques: in one case, we injected in the machine two bunches, one used as a reference with constant intensity, and the second one changing its intensity; in the second case, more conventional, we measured the bunch position with respect to the RF signal of the 40 MHz cavities. The obtained dependence of the synchrotron phase with intensity is then related to the loss factor and the resistive coupling impedance, which is compared to the real part of the PS impedance model.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR014
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOR018	Single Bunch Instability Studies at Diamond Light Source	impedance, simulation, synchrotron, betatron	637
	E. Koukovini-Platia, M. Apollonio, R. Bartolini, R.T. Fielder, I.P.S. Martin DLS, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	Single bunch instability thresholds, the associated coherent tune shifts and the bunch lengthening have been studied at Diamond light source for nominal optics. Measurements were taken under different settings of chromaticity, radio-frequency (RF) voltage and aperture of the insertion devices (IDs). The macro-particle code sbtrack was used to evaluate the instability thresholds and bunch lengthening where different impedance contributions are taken into account such as the resistive wall impedance, a broad-band resonator model and inductive impedance for the longitudinal plane. A comparison of simulation using the developed model impedance with measurements is shown for all cases.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR018
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOR025	3D Emittances Tailoring Techniques and Optimization with Space Charge for the Future CERN PS Booster Operations with Linac4	injection, emittance, simulation, linac	660
	V. Forte, J.L. Abelleira, E. Benedetto, C. Bracco, M. Cieslak-Kowalska, G.P. Di Giovanni CERN, Geneva, Switzerland
	In the frame of the LIU (LHC Injectors Upgrade) project, the CERN PS Booster is going to be renovated to host a new H⁻ charge-exchange injection from the Linac4. One important feature of the new injection scheme is the possibility to tailor a wide range of 3D emittances for CERN's different users in an intensity span in the order of 5·10⁹ to 1.6·10¹³ protons per PSB ring. This paper gives an overview of 3D multi-turn injection techniques, focusing on the future LHC beams, which aim at reaching high brightness, and on highest intensity beams (ISOLDE), where losses are the main concern. Complete RF capture simulations and transverse injection maps, including space charge effects, are presented and also intended to be used during the commissioning with Linac4.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR025
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOR039	Measurement of Beam Phase at FLASH using HOMs in Accelerating Cavities	HOM, cavity, electron, simulation	686
	L. Shi, R.M. Jones UMAN, Manchester, United Kingdom N. Baboi, L. Shi DESY, Hamburg, Germany N.Y. Joshi University of Manchester, Manchester, United Kingdom
	The beam phase relative to the accelerating field is of vital importance for the quality of photon beams produced in modern Free Electron Lasers based on superconducting (SC) cavities. Normally, the phase is determined by detecting the transient field induced by the beam. In this way the phase of each cavity is checked and adjusted typically every few months. In this paper, we present another means of beam phase determination, based on higher order modes (HOMs) excited in the 2nd monopole band by the beam inside the SC cavities. A circuit model of this HOM band is also presented. Various effects on the resolution have been studied. Circuit model simulations indicate the resolution is strongly dependent on the signal to noise ratio. Preliminary experimental results, based on a broadband setup, reveal an approximately 0.1o RMS resolution. These are in good agreement with simulation results. The work will pave the way for a dedicated system of beam phase monitoring, which is under development for the European XFEL. This will be the first implementation of a dedicated beam phase monitor, based on beam-excited HOMs in accelerating cavities.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR039
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUOBA01	Beam Commissioning of SuperKEKB	optics, vacuum, detector, septum	1019
	Y. Funakoshi, T. Abe, T. Adachi, K. Akai, Y. Arimoto, K. Egawa, Y. Enomoto, J.W. Flanagan, H. Fukuma, K. Furukawa, N. Iida, H. Iinuma, H. Ikeda, T. Ishibashi, M. Iwasaki, T. Kageyama, H. Kaji, T. Kamitani, T. Kawamoto, S. Kazama, M. Kikuchi, T. Kobayashi, K. Kodama, H. Koiso, M. Masuzawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, S. Nakamura, T.T. Nakamura, H. Nakayama, T. Natsui, M. Nishiwaki, K. Ohmi, Y. Ohnishi, T. Oki, S. Sasaki, M. Satoh, Y. Seimiya, K. Shibata, M. Suetake, Y. Suetsugu, H. Sugimoto, M. Tanaka, M. Tawada, S. Terui, M. Tobiyama, S. Uehara, S. Uno, X. Wang, K. Watanabe, Y. Yano, S.I. Yoshimoto, R. Zhang, D. Zhou, X. Zhou, Z.G. Zong KEK, Ibaraki, Japan D. El Khechen LAL, Orsay, France
	In this report, we describe the machine operation in the first 3 months of the Phase 1 commissioning of SuperKEKB. The beam commissioning is smoothly going on. Vacuum scrubbing, the optics corrections and others are described.
	Slides TUOBA01 [9.346 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOBA01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMR055	Solid Targetry for the Isotope Production Facility at the KOMAC 100 MeV Linac	target, proton, isotope-production, shielding	1384
	S.P. Yun, Y.-S. Cho, H.S. Kim, H.-J. Kwon, K.T. Seol, Y.G. Song Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea D.I. Kim KAERI, Daejon, Republic of Korea
	Funding: *This work was supported by the Ministry of Science, ICT and Future Planning of the Korean Government. The construction of the isotope production facility was recently completed on the 100 MeV proton linac at the KOMAC (Korea multi-purpose accelerator complex). To produce the Sr-82 and Cu-67, we have prepared the solid targetry which consist of target transportation system , target cooling system and a hot-cell for remote handling. The Isotope production targets are made of RbCl pellet and stainless steel cladding. For the proton beam irradiation, the targets are transported by target drive system which consist of drive chain and guide rail by remotely. In this paper, we will report the detailed design, fabrication and operation status of the solid targetry at the KOMAC isotope production facility.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR055
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPMW036	Optimizing Chromatic Coupling Measurement in the LHC	resonance, dipole, sextupole, quadrupole	1520
	T. Persson, R. Tomás CERN, Geneva, Switzerland
	Optimizing chromatic coupling measurement in the LHC Chromatic coupling introduces a dependency of transverse coupling with energy. LHC is equipped with skew sextupoles to compensate the possible adverse effects of chromatic coupling. In 2012 a beam-based correction was calculated and applied successfully for the fist time. However, the method used to reconstruct the chromatic coupling was dependent on stable tunes and equal chromaticities between the horizontal and vertical planes. In this article an improved method to calculate the chromatic coupling without these constraints is presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOW022	Hybrid Electron Linac With Standing and Travelling Wave Accelerating Sections	focusing, linac, impedance, electron	1791
	S.V. Matsievskiy, A.V. Bulanov, V.I. Kaminskiy, E.A. Savin, N.P. Sobenin MEPhI, Moscow, Russia R.Yu. Alekhanov NRNU, Moscow, Russia
	Hybrid electron linacs with standing and travelling wave accelerating sections are not well described in literature. Limited number of studies have shown that application of these systems makes it possible to develop a compact linac with high efficiency and simpler power system. Typically, these systems use well-studied bi-periodical accelerating structure (BAS) cells for a standing wave section and disc-loaded waveguides (DLW) for a traveling wave section. This paper describes the development of such system using DLW cells with magnetic coupling (DLW-M). Here BAS appears as an absorbing load connected to the DLW-M accelerating structure by rectangular waveguide allowing to have theoretical zero reflection at RF input. Such system also provides possibility of plain beam output energy adjustment. Studies of the structure were carried out using equivalent circuits methods and numerical 3D-modeling. Beam dynamics was calculated.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW022
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOW023	New 10 MeV High-power Electron Linac for Industrial Application	linac, simulation, electron, bunching	1794
	S.M. Polozov, D.S. Bazyl, T.V. Bondarenko, M. Gusarova, Yu.D. Kliuchevskaia, M.V. Lalayan, V.I. Rashchikov, E.A. Savin MEPhI, Moscow, Russia M.I. Demsky, A.A. Eliseev, V.V. Krotov, D.E. Trifonov CORAD Ltd., St. Petersburg, Russia B.S. Han, W.G. Kang, H.G. Park EB TECH Co. Ltd., Daejeon, Republic of Korea
	Joint team of CORAD and MEPhI developed a new industrial accelerating structure for average beam power up to 20 kW and energy range from 7.5 to 10 MeV. The use of modern methods and codes for beam dynamics simulation, raised coupling coefficient and group velocity of SW biperiodic accelerating structure allowed to reach high pulse power utilization and obtain high efficiency. Gentle buncher provides high capturing coefficient and narrow energy spectrum. The first linear accelerator with this structure was constructed and tested in collaboration with the company EB Tech.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW023
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOW024	Compact Standing Wave Electron Linac with the Hybrid Accelerating and Power Generation Cell	electron, cavity, Windows, linac	1797
	E.A. Savin, S.V. Matsievskiy, N.P. Sobenin, I.D. Sokolov MEPhI, Moscow, Russia A.A. Zavadtsev Nano, Moscow, Russia
	Compact electron linear accelerators for small energies are now found their place in the industrial market. Such accelerators are used for cancer treatment, cargo inspection, when one needs higher dose that X-ray source can produce, food and medicaments irradiation etc. Acceleration structures themselves are already developed very well, so the most important issue now ' is to make the whole installation with power supply, RF tracts, cooling system ' as smaller as possible to provide the structure mobility. In this article we present the development how to combine a power supply (usually it is a klystron, IOT, magnetron or solid state amplifier) with the accelerating cell itself, that can decrease installation size at least twice. No RF tracts needed, no reflected power will occur, so no circulator needed. Different power input combinations have been studied, but the smallest and the most efficient one has been manufactured for cold tests at S-band frequency range. In this structure it is very easy to vary accelerating voltage simply changing the generator beam current or the generator beam accelerating voltage.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW024
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOW040	UH-FLUX: Compact, Energy Efficient Superconducting Asymmetric Energy Recovery LINAC for Ultra-high Fluxes of X-ray and THz Radiation	cavity, HOM, electron, radiation	1847
	I.V. Konoplev, A. Seryi JAI, Oxford, United Kingdom R. Ainsworth Fermilab, Batavia, Illinois, USA G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	Funding: This work was supported (in part) by The Leverhulme Trust through the International Network Grant IN-2015-012. The conventional ERLs have limited peak beam current because increasing the beam charge and repetition rate leads to appearance of the beam break-up instabilities. At this stage the highest current, from the SRF ERL, is around 300 mA. A single turn (the beam will be transported through the accelerating section, interaction point and deceleration section of the AERL only once) Asymmetric Energy Recovery LINAC (AERL) is proposed. The RF cells in different sections of the cavity are tuned in such a way that only operating mode is uniform inside all of the cells. The AERL will drive the electron beams with typical energies of 10 - 30 MeV and peak currents above 1 A, enabling the generation of high flux UV/X-rays and high power coherent THz radiation. We aim to build a copper prototype of the RF cavity for a compact AERL to study its EM properties. The final goal is to build AERL based on the superconducting RF cavity. Preliminary design for AERL's cavity has been developed and will be presented. The results of numerical and analytical models and the next steps toward the AERL operation will also be discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW040
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOY014	PSI Gantry 3: Integration of a New Gantry into an Existing Proton Therapy Facility	controls, interface, proton, optics	1927
	A. Koschik, C. Baumgarten, C. Bula, J.P. Duppich, A. Gerbershagen, M. Grossmann, V. Rizzoglio, J. Welte PSI, Villigen PSI, Switzerland
	Paul Scherrer Institute extends its proton therapy facility PROSCAN by a third gantry. It is delivered by Varian Medical Systems (VMS) as part of a joint research project. Gantry 3 is equipped with a cone beam CT and allows 360 degrees of rotation while occupying a 10.5 m diameter. The integration of a gantry into the existing PSI-system typically being designed for a complete Varian system is a challenging project, since also the certification is to be maintained. Especially the interfaces between the PROSCAN-control system and the one of Gantry 3 have been a major development. Gantry 3 is designed to deliver proton beam of up to 8 nA with an accuracy better than a mm, while having a high level of over-current protection. This comprises a new current monitoring unit, several levels of interlock controllers and a beam energy dependent intensity compensation concept. One challenge concerns the specified layer switching time of 200 ms, required to reduce the treatment time to enable for repainting. After technical commissioning, acceptance tests and hand over, the clinical commissioning is foreseen in the second half of 2016 with the first patient treatment in December 2016.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY014
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOY039	Studies on Electron Linear Accelerator System for Polymer Research	electron, linac, radiation, plasma	1985
	E. Kongmon IST, Chiang Mai, Thailand N. Kangrang Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand S. Rimjaem, J. Saisut, C. Thongbai Chiang Mai University, Chiang Mai, Thailand P. Wichaisirimongkol Chiang Mai University, Science and Technology Research Institute, Chiang Mai, Thailand
	This research focuses on modification of an elec-tron linear accelerator system for irradiation of natural rubber latex and polymeric materials at the Plasma and Beam Physics Research Facility, Chiang Mai Universi-ty, Thailand. This is in order to study the change of material properties due to electron beam irradiation. The main accelerator system consists of a DC thermi-onic electron gun and a short standing-wave linac. This system will be able to produce electron beams with variable energy in the range of 0.5 to 4 MeV. The linac macro pulse frequency is adjustable within the range of 20 to 1000 Hz. The macro pulse duration is 4 μs. The electron pulse current can be varied from 10 to 100 mA. This lead to the electron dose of about 0.44 to 4.4 Gy-m2/min. In this paper, overview of the accelera-tor and the irradiation system is presented. Results of low-level RF measurements of the accelerating struc-ture are also reported and discussed. This work has been supported by the CMU Junior Research Fellowship Program, the Department of Physics and Material Science, Faculty of science, Chiang Mai University.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY039
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOY041	A Metal-Dielectric Micro-Linac for Radiography Source Replacement	focusing, linac, electron, vacuum	1992
	A.V. Smirnov, S. Boucher, S.V. Kutsaev RadiaBeam Systems, Santa Monica, California, USA R.B. Agustsson, R.D.B. Berry, J.J. Hartzell, J. McNevin, A.Y. Murokh RadiaBeam, Santa Monica, California, USA G. Leyh LOD, Brisbane, USA E.A. Savin MEPhI, Moscow, Russia
	Funding: * US Department of Energy Contract # DE-SC0011370 To improve public security and prevent the diversion of radioactive material for Radiation Dispersion Devices, RadiaBeam is developing an inexpensive, portable, easy-to-manufacture linac structure to allow effective capture of a ~13 keV electron beam injected from a conventional electron gun and acceleration to a final energy of ~ 1 MeV. The bremsstrahlung X-rays produced by the electron beam on a high-Z converter at the end of the linac will match the penetration and dose rate of a typical ~100 Ci or more Ir-192 source. The tubular Disk-and-Ring structure under development consists of metal and dielectric elements that reduce or even eliminate multi-cell, multi-step brazing. This may allow significant simplification of the fabrication process to enable inexpensive mass-production required for replacement of the ~55,000 radionuclide sources in the US
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY041
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEOAA01	Transverse Emittance Exchange for Improved Injection Efficiency	emittance, resonance, synchrotron, injection	2028
	P. Kuske, F. Kramer HZB, Berlin, Germany
	In most cases beam is injected into electron storage rings in the horizontal plane and off-axis. The larger the horizontal emittance of the injected beam the larger the acceptance of the ring has to be. The injected beam is usually delivered by a synchrotron. In case the vertical acceptance of the ring is sufficiently large one can take advantage of the small vertical emittance reached in well aligned and tuned synchrotrons since the transverse emit-tances can be exchanged with the help of skew quadru-pole magnets. A few possible processes will be discussed: emittance exchange with static magnets in the transfer line between synchrotron and ring or emittance exchange in the synchrotron shortly before extraction with time dependent magnets. This could be a suddenly switched-on normal or skew quadrupole magnet or skew quadru-pole fields oscillating at a frequency fulfilling the reso-nance condition. Estimates for these magnets and their design will be given.
	Slides WEOAA01 [0.852 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMB011	ESS Medium and High Beta Cavity Prototypes	cavity, HOM, cryomodule, interface	2138
	P. Michelato, A. Bellandi, M. Bertucci, A. Bignami, A. Bosotti, J.F. Chen, L. Monaco, R. Paparella, P. Pierini, D. Sertore INFN/LASA, Segrate (MI), Italy C.G. Maiano DESY, Hamburg, Germany C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy S. Pirani ESS, Lund, Sweden
	In the framework of the ESS activity in progress at INFN-LASA, we are designing and developing 704.42 MHz Medium (β=0.67) and High (β=0.86) beta prototype cavities plug compatible with the ESS cryomodule design. The cells of one Medium and one High beta cavity are fabricated with high quality CBMM Large Grain Niobium (480 mm dia. Ingot, RRR=300, sliced by Heraeus) while a Medium beta cavity is done with Fine Grain material for comparison. The prototype cavities will be produced by the firm Ettore Zanon S.p.A. under the supervision of INFN - LASA group.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMB060	Modifications to the Pump Out Box to Lower the Qext of Diamond SCRF Cavities	cavity, operation, simulation, electron	2251
	S.A. Pande, C. Christou, P. Gu DLS, Oxfordshire, United Kingdom G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	Diamond's CESR-B cavities are iris coupled and have fixed Qext. For reliability, the cavities are operated at lower voltages. This results in the optimum condition for beam loading being satisfied at a much lower power typically about 100 kW. For operation at 300 mA with two cavities, the RF power needed per system exceeds 200 kW. Consequently, the cavities need to be operated under-coupled. To lower the Qext and move the optimum operating point nearer to 200kW, 3 stub tuners are used in the waveguide feed line. The difference in the height of the coupling waveguide on cavity and that of the vacuum side waveguide on the window assembly results in a step transition which affects the Qext. The present window/step location results in Qext higher than that without the window. The Qext can be lowered by re-locating the RF window or by shifting the step change in the waveguide cross-section from its present location. This needs modification to the Pump Out box. The pros and cons of the proposed modification to the pump out box in terms of standing waves and multipacting characteristics studied with CST Studio are discussed in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB060
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMW015	Evaluation and Compensation of Detector Solenoid Effects in the JLEIC	solenoid, detector, ion, quadrupole	2454
	G.H. Wei, F. Lin, V.S. Morozov, F.C. Pilat, Y. Zhang JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported also by the U.S. DOE Contract DE-AC02-76SF00515. The JLEIC detector solenoid has a strong 3 T field in the IR area, and its tails extend over a range of several meters. One of the main effects of the solenoid field is coupling of the horizontal and vertical betatron motions which must be corrected in order to preserve the dynamical stability and beam spot size match at the IP. Additional effects include influence on the orbit and dispersion caused by the angle between the solenoid axis and the beam orbit. Meanwhile it affects ion polarization breaking the figure-8 spin symmetry. Crab dynamics further complicates the picture. All of these effects have to be compensated or accounted for. The proposed correction system is equivalent to the Rotating Frame Method. However, it does not involve physical rotation of elements. It provides local compensation of the solenoid effects independently for each side of the IR. It includes skew quadrupoles, dipole correctors and anti-solenoids to cancel perturbations to the orbit and linear optics. The skew quadrupoles and FFQ together generate an effect equivalent to adjustable rotation angle to do the decoupling task. Details of all of the correction systems are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW015
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMW029	Simulation of Heavy-Ion Beam Losses with the SixTrack-FLUKA Active Coupling	ion, heavy-ion, simulation, collimation	2490
	P.D. Hermes, R. Bruce, F. Cerutti, A. Ferrari, J.M. Jowett, A. Lechner, A. Mereghetti, D. Mirarchi, P.G. Ortega, S. Redaelli, B. Salvachua, E. Skordis, G. Valentino, V. Vlachoudis CERN, Geneva, Switzerland
	Funding: Work suppported by the Wolfgang Gentner Programme of the German BMBF The LHC heavy-ion program aims to further increase the stored ion beam energy, putting high demands on the LHC collimation system. Accurate simulations of the ion collimation efficiency are crucial to validate the feasibility of new proposed configurations and beam parameters. In this paper we present a generalized framework of the SixTrack-FLUKA coupling to simulate the fragmentation of heavy-ions in the collimators and their motion in the LHC lattice. We compare heavy-ion loss maps simulated on the basis of this framework with the loss distributions measured during heavy-ion operation in 2011 and 2015.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW029
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMY037	Cold Model Cavity for 20-K Cryocooled C-band Photocathode RF Gun	simulation, cavity, gun, impedance	2635
	T. Tanaka, M. Inagaki, R. Nagashima, K. Nakao, K. Nogami, T. Sakai, K. Takatsuka LEBRA, Funabashi, Japan M.K. Fukuda, T. Takatomi, N. Terunuma, J. Urakawa, M. Yoshida KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	Funding: Work supported by the Photon and Quantum Basic Research Coordinated Development Program of the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT). A cryocooled 2.6-cell C-band photocathode RF gun is under development at Nihon University in collaboration with KEK. The RF characteristics of a pillbox-type 2.6-cell C-band RF cavity at 20 K were in agreement with the theoretical predictions. The result of the cold test for a cavity with the input coupler confirmed the same characteristics. Based on these results a refined cold model of the 20-K cryocooled photocathode RF gun has been designed using SUPERFISH and CST-STUDIO. The separation between the TM01 pi and the TM01 half-pi modes has been increased from 20 MHz to 52 MHz by extending the diameter of the cavity iris and reducing the disk thickness. The 2.6-cell structure has been modified from pillbox to ellipsoid-like type. The end-plate of the 0.6-cell cavity has a center hole for bead-pull measurements of the on-axis electric filed through the entire structure. Mounting of a photocathode assembly in the end-plate has not been considered, since the purpose is solely to measure the low-power and low-temperature RF characteristics. A new design for the input coupler has been employed. The cavity will be completed early in 2016.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY037
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPMY038	Optimization of C-band RF Input Coupler as a Mode Converter for 20-K Cryocooled Photocathode RF Gun	cavity, gun, simulation, insertion	2638
	T. Tanaka, M. Inagaki, R. Nagashima, K. Nakao, K. Nogami, T. Sakai, K. Takatsuka LEBRA, Funabashi, Japan M.K. Fukuda, T. Takatomi, N. Terunuma, J. Urakawa, M. Yoshida KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	Funding: Work supported by the Photon and Quantum Basic Research Coordinated Development Program of the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT). Development of a cryocooled 2.6-cell C-band photocathode RF gun has been conducted at Nihon University in collaboration with KEK. An RF mode converter from square TE10 to circular TM01 mode has been employed as an RF input coupler that has a coupling coefficient of approximately 20 at 20 K to the 2.6-cell accelerating structure. In the previous design, the circular waveguide in the mode converter formed part of the accelerating cavity. After the cold test of the cavity completed in 2014, the coupler design was modified to work as a pure mode converter with a VSWR of 1 at 5712 MHz. From the design simulation using CST-STUDIO, the insertion loss in the converter is 0.2 %. The TM010 and TM011 modes excited in the circular waveguide were separated by several ten MHz from the accelerating frequency. The simulation has suggested that the amplitude of the transverse electric filed on the axis in the circular waveguide is reduced to approximately 2 % of that in the longitudinal direction.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY038
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOR008	Development of a High Resolution Beam Position Monitor for NSRRC VUV/THz FEL	cavity, dipole, electron, simulation	2680
	P.J. Kung, K.C. Leou NTHU, Hsinchu, Taiwan W.K. Lau, A.P. Lee NSRRC, Hsinchu, Taiwan
	Beam position monitors (BPM) have been widely used on linear colliders and free electron lasers for beam-based alignment and feedback systems. A laser driven photo-injector system has been constructed in NSRRC. This injector has the capability to deliver short relativistic electron beam at high peak current for novel light source R&D. A 2.4 GHz BPM that can be used for high precision beam position measurement has been designed. The BPM were modified to separate frequency between the horizontal and vertical dipole signals, as well as a reduction of the monopole signal. The design has been simulated by CST. A prototype has been built for verification of theoretical predictions. Microwave bench measurement has been made to compare with the computer simulation results. The progress of our work will be presented in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR008
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMB006	Unclosed Lattice Dispersions as a Tool for Partial Removal of Transverse to Longitudinal Beam Correlations	emittance, lattice, synchrotron, optics	3229
	V. Balandin, W. Decking, N. Golubeva DESY, Hamburg, Germany
	We show how to choose unclosed lattice dispersions in order to zero either linear beam dispersions (linear correlations between energy of particles and their transverse positions and momenta) or linear beam tilts (linear correlations between longitudinal positions of particles and their transverse coordinates). Besides that, we prove that while removal of beam dispersions always leads to reduction of transverse projected emittances, zeroing of beam tilts cannot guarantee it.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB006
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMB049	Optics Calibration During Commissioning of the Taiwan Photon Source	optics, lattice, quadrupole, emittance	3357
	F.H. Tseng, C.H. Chen, J.Y. Chen, M.-S. Chiu, C.-C. Kuo, Y.-C. Liu, H.-J. Tsai NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source is a 3-GeV low emittance synchrotron light machine with circumference of 518.4m. The lattice is with 24-cell DBA structure and emittance is 1.6 nm-rad. During the commissioning in the past year, we employed MATLAB-based high level applications to calibrate the optical functions in three different operation lattice modes. In particular, we used LOCO (Linear Optics from Closed Orbit) to restore the machine optical functions and reduce emittance coupling ratio. The beam-based alignment (BBA) measurements as well as BPM and corrector errors were identified.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB049
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMB050	The Commmissioning of Phase-I Insertion Devices in TPS	storage-ring, lattice, undulator, radiation	3360
	M.-S. Chiu, C.H. Chang, C.H. Chen, J. Chen, J.Y. Chen, Y.-S. Cheng, P.C. Chiu, P.J. Chou, T.Y. Chung, S. Fann, K.H. Hu, C.H. Huang, J.C. Huang, C.-S. Hwang, C.-C. Kuo, T.Y. Lee, C.C. Liang, Y.-C. Liu, H.-J. Tsai, F.H. Tseng, C.Y. Wu NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is a low-emittance 3-GeV light source at Natioal Synchrotron Radiation Research Center, next to the Taiwan Light source (1.5 GeV). On March 26, 2015, the TPS storage ring with two 5-cell PETRA cavities has successfully operated in 100 mA in top-up mode without the installation of insertion devices (IDs). To reach the design goal of 500 mA, the machine was shut down for 5 months to replace PETRA cavitites with superconducting RF (SRF) cavities and to install 10 IDs: 7 in-vacuum undulators (IU) and 3 elliptically polarized undulators (EPU). The commissioning of TPS storage ring with SRF cavities and IDs began in Sep. 2015. In this paper, we present our results and proceedures of ID commissioning.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB050
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMR038	Non-Linear Errors in the Experimental Insertions of the LHC	insertion, multipole, dipole, dynamic-aperture	3472
	E.H. Maclean, F.S. Carlier, M. Giovannozzi, A. Langner, S. Mönig, T. Persson, P.K. Skowroński, R. Tomás CERN, Geneva, Switzerland
	Correction of nonlinear magnetic errors in low-β insertions can be of critical significance for the operation of a collider. This is expected to be of particular relevance to LHC Run II and the HL-LHC upgrade, as well as to future colliders such as the FCC. Current correction strategies for these accelerators have assumed it will be possible to calculate optimized local corrections through the insertions using a magnetic model of the errors. To test this assumption the nonlinear errors in the LHC experimental insertions have been examined via feed-down and amplitude detuning. It will be shown that while in some cases the magnetic measurements provide a sufficient description of the errors, in others large discrepancies exist which will require beam-based correction techniques.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR038
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMR040	Local Optics Corrections in the HL-LHC IR	optics, quadrupole, controls, simulation	3480
	J.M. Coello de Portugal, F.S. Carlier, A. Garcia-Tabares, A. Langner, E.H. Maclean, L. Malina, T. Persson, P.K. Skowroński, R. Tomás CERN, Geneva, Switzerland
	For the high luminosity upgrade of the LHC optics correction in the interaction regions is expected to be challenged by the very low β^* and the sizable expected quadrupolar errors in the triplet. This paper addresses the performance and limitations of the segment-by-segment technique to correct quadrupolar and skew quadrupolar errors in the HL-LHC IR via computer simulations. Required improvements to this technique and possible combinations with other correction approaches are also presented including experimental tests in the current LHC IR.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR040
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMR048	Analysis of Nonlinear Effects for IDs at the SPS Storage Ring	electron, storage-ring, injection, quadrupole	3512
	S. Krainara, P. Klysubun, S. Kongtawong, T. Pulampong, P. Sudmuang, P. Sunwong SLRI, Nakhon Ratchasima, Thailand
	Funding: Synchrotron Light Research Institute (Public Organization) To generate intense and high energy synchrotron radiation at the Siam Photon Source (SPS) 1.2 GeV storage ring, two insertion devices (IDs), namely, a 2.2 T hybrid multipole wiggler (MPW) and a 6.5 T superconducting wavelength shifter (SWLS), have been installed and operated since 2013. The angular kicks due to the nonlinear effects generated by the IDs represented by kick maps were used in our analysis. The optics distortion was compared to the ones obtained from calculation using hard-edge model and measurement results. In order to investigate the effects of IDs on the beam dynamics, Frequency Map Analysis (FMA) was employed. The effects of the IDs and their compensation are presented herewith.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMW030	Studies of Impedance-related Improvements of the SPS Injection Kicker System	kicker, impedance, simulation, vacuum	3611
	M.J. Barnes, A. Adraktas, M.S. Beck, G. Bregliozzi, H.A. Day, L. Ducimetière, J.A. Ferreira Somoza, B. Goddard, T. Kramer, C. Pasquino, G. Rumolo, B. Salvant, L. Sermeus, J.A. Uythoven, L. Vega Cid, W.J.M. Weterings, C. Zannini CERN, Geneva, Switzerland F.M. Velotti EPFL, Lausanne, Switzerland
	The injection kicker system for the SPS consists of sixteen magnets housed in a total of four vacuum tanks. The kicker magnets in one tank have recently limited operation of the SPS with high-intensity beam: this is due to both beam induced heating in the ferrite yoke of the kicker magnets and abnormally high pressure in the vacuum tank. Furthermore, operation with the higher intensity beams needed in the future for HL-LHC is expected to exacerbate these problems. Hence studies of the longitudinal beam coupling impedance of the kicker magnets have been carried out to investigate effective methods to shield the ferrite yoke from the circulating beam. The shielding must not compromise the field quality or high voltage behaviour of the kicker magnets and should not significantly reduce the beam aperture: results of these studies, together with measurements, are presented. In addition results of tests to identify the causes of abnormal outgassing are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMW031	Current and Future Beam Thermal Behaviour of the LHC Injection Kicker Magnet	impedance, kicker, injection, simulation	3615
	H.A. Day, M.J. Barnes, L. Ducimetière, L. Vega Cid, W.J.M. Weterings CERN, Geneva, Switzerland
	During Run 1 of the LHC the injection kicker magnets caused occasional operational delays due to beam induced heating with high bunch intensity and short bunch lengths. Significant upgrades were carried out to the injection kicker magnets during long shutdown 1, including a new design of beam screen to reduce the beam induced heating. Nevertheless these kicker magnets may limit the performance of HL-LHC unless additional, mitigating, measures are taken. Hence extensive simulations have been carried out to predict the distribution of the beam induced power deposition within the magnet and detailed thermal analyses carried out to predict the temperature profiles. To benchmark the simulations the predicted temperatures are compared with observables in the LHC. This paper reports on observations of the thermal behaviour of the magnet during run 2 of the LHC, with 25ns beam. In addition the measurement data is used to extrapolate temperature rise for the beam parameters expected for high-luminosity LHC.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW031
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMW038	Prototyping of the ALS-U Fast Kickers	kicker, impedance, vacuum, injection	3637
	G.C. Pappas, S. De Santis, J.-Y. Jung, T.H. Luo, C. Steier, C.A. Swenson, W.L. Waldron LBNL, Berkeley, California, USA
	Prototyping of major components for the ALS-U kickers is in progress. A tapered stripline kicker has been built for installation and testing in the ALS, and multiple modulator options to meet the fast rise time required for swap out injection have been considered. High voltage feedthroughs that are matched into the multi GHz range are also being studied. * Pappas et al., "Fast Kicker Systems for ALS-U", Proc. of IPAC'14, Dresden, Germany, MOPME083.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW038
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMY009	Coaxial Wire Method Adapted to Weakly Coupled Resonator Mode for LHC RF Fingers Evaluation	resonance, impedance, cavity, vacuum	3670
	C. Vollinger, F. Caspers, T. Kaltenbacher CERN, Geneva, Switzerland
	In high intensity particle accelerators, RF contact fingers are commonly used to carry the beam induced image current. In addition, they reduce beam impedance by shielding the outer bellows required to compensate mechanical displacements between components. In order to assess the resulting beam impedance from a specific bellow/RF finger configuration, RF measurements are routinely carried out. During these measurements, it was observed that cavity modes in the volume between the fingers and the bellow undulation arise. These resonances occur at significantly higher frequencies than the expected frequency range of interest. Due to their broadband nature, the tails of the imaginary part of these resonances reach into the lower frequency range of interest where it contributes to the beam coupling impedance of the device. For proper evaluation of this contribution, a time domain delay technique in TDT (time domain transmissiometry) was used in order to overcome shortcomings that arise if the classical coaxial wire method is applied to these structures. We present the theory of our method and discuss it in view of the data measured on deformable fingers that were studied for the LHC.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY009
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMY033	Vibration Evaluation for Deionized Water Pumps in TPS	operation, booster, alignment, status	3731
	Y.-H. Liu, C.S. Chen, Y.-C. Chung NSRRC, Hsinchu, Taiwan
	The purpose of this paper is to evaluate the vibration level and spectrum for TPS deionized water pumps. The utility systems started to operate from the beginning of 2014, some of deionized water pumps produced higher vibration level and noise during operation. The possibly reason could be not appropriated installation and commission test. In order to figure out the status of these deionized water pumps, the vibration analysis become needed. After vibration test, the booster(BO) and copper(CU) deionized water pump systems generate higher vibration level. According to the vibration test results, the pump is repair and maintain. Although there is some problems for TPS deionized water pumps, the vibration test is still one important way to maintain utility systems. The utility systems could prevent malfunction through regular vibration inspection.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY033
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOR007	Optics Measurements and Corrections at the Early Commissioning of SuperKEKB	sextupole, optics, quadrupole, emittance	3782
	Y. Ohnishi, Y. Funakoshi, H. Koiso, A. Morita, K. Ohmi, K. Oide, H. Sugimoto, D. Zhou KEK, Ibaraki, Japan M.E. Biagini, M. Boscolo, S. Guiducci INFN/LNF, Frascati (Roma), Italy N. Carmignani, S.M. Liuzzo ESRF, Grenoble, France
	We present experimental results of measurements and corrections of the optics at the early Phase-1 commissioning of SuperKEKB which is a positron-electron collider built to achieve the target luminosity of 8x10³⁵ cm^-2s^-1. We have three stages; the Phase-1 is the commissioning of the machine without the final focus magnets and detector solenoid(no collision); the collision with the final focus system and the Belle II detector will be performed at the Phase-2 and Phase-3. The strategy for the luminosity upgrade is a novel "nano-beam'' scheme found elsewhere. In order to achieve the target luminosity, the vertical emittance has to be reduced by corrections of machine error measured by orbit responses. The vertical emittance should be achieved to be less than 6 pm(0.2 % coupling) during the Phase-1 by fully utilizing correction tools of skew quadrupole-like coils wound on sextupole magnets and power supplies for each correction coil in quadrupole magnets. In addition to the linear optics, the optics for off-momentum particles is also studied to understand a dynamic aperture affects the Touschek lifetime. "SuperB Conceptual Design Report", INFN/AE-07/2, SLAV-R-856, LAL 07-15, (2007).
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOR029	First Start-to-End BBA Results in the CLIC RTML	emittance, sextupole, quadrupole, alignment	3841
	Y. Han, L. Ma SDU, Shandong, People's Republic of China A. Latina, D. Schulte CERN, Geneva, Switzerland
	CLIC is a design study for a 3 TeV linear collider designed for the high-energy frontier in the post-LHC era. The Ring To Main Linac (RTML) part of CLIC is a long section that must transport the electron and the positron bunches through more than 20 km of beamlines, with minimal emittance growth. A sequence of three beam-based alignment (BBA) techniques must be used to transport the beam: one-to-one correction (OTO), dispersion-free steering (DFS), and sextupole correction (SCS). The performance of the whole correction procedure is tested under several realistic imperfections: magnets position offsets, magnets rotation errors, magnets strength errors and emittance measurement errors. The results show that the emittance growth budgets can be met both in the horizontal and vertical planes.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR029
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOR043	High Power Test of X-band Single Cell HOM-free Choke-mode Damped Accelerating Structure made by Tsinghua University	cavity, operation, vacuum, HOM	3881
	X.W. Wu, H.B. Chen, J. Shi TUB, Beijing, People's Republic of China T. Abe, T. Higo KEK, Ibaraki, Japan W. Wuensch, H. Zha CERN, Geneva, Switzerland
	As an alternative design for CLIC main accelerating structures, X-band choke-mode damped structures had been studied for several years. However, the performance of choke-mode cavity under high power is still in lack of research. Two standing wave single cell choke-mode damped accelerating structures with different choke dimensions which are working at 11.424 GHz were designed, manufactured and bench tested by accelerator group in Tsinghua University. High power test was carried out on it to study the breakdown phenomenon in high gradient. A single cell structure without choke which almost has the same inner dimension as choke-mode cavity will also be tested to make a comparison and study how the choke affects high-gradient properties.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR043
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOW001	Design of a 4.6-Cell RF Gun for the PHIL accelerator at LAL	gun, emittance, cavity, impedance	3922
	P. Chen, C. Bruni, S. Chancé, L. Garolfi, A. Gonnin, P. Lepercq, T. Vinatier LAL, Orsay, France
	A photo-injector with 4.6-cell and resonate frequency of 2.998 GHz has been designed and studied to replace the 2.5-cell RF gun + booster association. The cavity iris shape and dimensions were simulated systematically to optimize the shunt impedance. In this study, electron beam reaches to 9.7 MeV with a moderate peak accelerat-ing gradient of 80 MV/m. Considering a beam charge of 1 nC/bunch, average transverse emittance of ~ 5.9 πmm mrad and energy spread of ~ 0.8% can be obtained at the exit of the gun. The RF input power is only 10.2 MW due to the high shunt impedance. Asymmetry of the electric field due to the coupling port has also been studied using 3D codes for RF and beam dynamics calculations. We will present the RF design and beam calculations results.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW001
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOW002	Electromagnetic, Thermal, and Structural Analysis of a THOMX RF Gun Using ANSYS	gun, cavity, electron, simulation	3925
	M. El Khaldi, J. Bonis, A. Camara, L. Garolfi, A. Gonnin LAL, Orsay, France
	Photocathode RF guns are used in the first stage of electron beam generation and acceleration. The RF gun of THOMX is a 2.5 cell standing wave copper cavity with resonance frequency of 2998.55 MHz at 30 °C under vacuum. The metal photocathode such as copper or magnesium is inserted into the backplane of the cavity. Due to high repetition rates up to 50 Hz with the average dissipated power into the internal surfaces up to 1.5 kW, causing a heating and deformation of the cavity shape. Therefore, the cooling system of the device has to be well designed to take under control the deformations of the structure, providing a temperature increase as small and uniform as possible. For this purpose a fully coupled electromagnetic-thermal-structural finite element analysis on this gun has been performed with Ansys workbench. Numerical results show that the gun could operate at 3 μs RF pulse length and 50 Hz repetition rate with an average dissipated power of 1.5 kW. The gun average temperature is around 30 °C while the incoming water temperature is around 24°C. Internal speed of water is 2.5 m/s which corresponds to 15 l/min for the incoming water. The total pressure drop is around 0.4 bar
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW002
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOW028	Automated Design for Standing Wave Electron Photoguns: TOPGUN RF Design	gun, toolkit, simulation, cavity	3999
	A.D. Cahill UCLA, Los Angeles, California, USA M. Dal Forno, V.A. Dolgashev SLAC, Menlo Park, California, USA
	Funding: DOE SCGSR and DOE/SU Contract DE-AC02-76-SF00515 Systematic design of RF photoguns involves multiple RF simulations in conjunction with beam dynamic simulations. RF simulations include tuning gun frequency, matching the gun to the feeding RF circuit, balancing the on axis electric fields between gun cells, minimizing surface electric and magnetic fields and power consumption, and optimizing separation of resonant mode frequencies. We created a tool that allows this multiple parameter optimization to be done automatically. We used SUPERFISH to accomplish the RF simulations. We present an example of the rf photogun TOPGUN design using these tools.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW028
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOYBA01

Limits and Possibilities of Laser Wakefield Accelerators

electron, laser, plasma, focusing

16

W. Leemans
LBNL, Berkeley, California, USA

This presentation provides an outlook into the future of laser-driven plasma wakefield accelerators. What has been achieved, what more is possible and what are the limits.

Slides MOYBA01 [43.465 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOYBA01

Export •

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

MOYCA01

Review of Linear Optics Measurements and Corrections in Accelerators

optics, quadrupole, collider, betatron

20

R. Tomás
CERN, Geneva, Switzerland
M. Aiba
PSI, Villigen PSI, Switzerland
A. Franchi
ESRF, Grenoble, France
U. Iriso
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The measurement and correction of optics parameters has been a major concern since the advent of strong focusing synchrotron accelerators. Traditionally, colliders have led the development of methods for optics control based on turn-by-turn centroid data, while lepton storage rings have focused on closed orbit response techniques. Recently considerable efforts are being invested in comparing these techniques in different light sources and colliders. An emerging class of less invasive optics control techniques based on the optimization of performance related observables is demonstrating a great potential. A review of the existing techniques is presented highlighting comparisons, merits and limitations.

Slides MOYCA01 [4.184 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOYCA01

Export •

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

MOOCA01

R&D of a Super-compact SLED System at SLAC

cavity, operation, impedance, FEL

39

J.W. Wang, G.B. Bowden, S. Condamoor, Y. Ding, V.A. Dolgashev, J.P. Eichner, M.A. Franzi, A.A. Haase, P. Krejcik, J.R. Lewandowski, S.G. Tantawi, L. Xiao, C. Xu
SLAC, Menlo Park, California, USA

Funding: Work supported by Department of Energy contract DE-AC03-76SF00515.
We have successfully designed, fabricated, installed and tested a super-compact X-Band SLED system at SLAC. It is composed of an elegant mode converter/polarizer and a single sphere energy store cavity with high Q of 94000 and diameter less than 12 cm. The available RF peak power of 50 MW can be compressed to peak average power of more than 200 MW in order to double the kick for the electron bunches in a RF transverse deflector system and greatly improve the measurement resolution for both the electron bunch and the x-ray FEL pulse. High power operation has demonstrated the excellent performance of this RF compression system without any problems in RF breakdown, pulse heating and radiation. The design physics and fabrication as well as the measurement results will be presented in detail.

Slides MOOCA01 [20.278 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOOCA01

Export •

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

MOPMB008

Modeling and Experimental Studies of Beam Halo at ATF2

vacuum, scattering, damping, optics

88

R.J. Yang, P. Bambade, V. Kubytskyi
LAL, Orsay, France
A. Faus-Golfe, N. Fuster-Martínez
IFIC, Valencia, Spain
T. Naito
KEK, Ibaraki, Japan

The Accelerator Test Facility 2 (ATF2) at KEK is a prototype of the final focus system for the next generation of Future Linear Colliders(FCL). It aims to focus the beams to tens of nanometer transverse sizes and to provide stability at the few nm level. Achieving these goals requires modelling, measuring and suppressing of the transverse beam halo before the interaction point (IP). This paper presents a beam tail/halo generator based on realistic model and the investigation of vertical and horizontal beam tail/halo distribution at ATF2.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB008

Export •

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

MOPMB011

ROSE, Measuring the Full 4D Transverse Beam Matrix of Ion Beams

emittance, ion, vacuum, detector

98

M.T. Maier, X. Du, P. Gerhard, L. Groening, S. Mickat, H. Vormann, C. Xiao
GSI, Darmstadt, Germany

A ROtating System for Emittance measurements ROSE, to measure the full 4 dimensional transverse beam matrix of an ion beam has been developed and commissioned. Different ion beams behind the HLI at GSI have been used in two commissioning beam times. All technical aspects of ROSE have been tested, ROSE has been benchmarked against existing emittance scanners for horizontal and vertical projections, and the method, hard-, and software to measure the 4D beam matrix has been upgraded, refined, and successfully commissioned. The inter plane correlations of the HLI beam have been measured, yet as no significant initial correlations were found to be present, controlled coupling of the beam by using a skew triplet has been applied and confirmed with ROSE. The next step is to use ROSE to measure and remove the known inter plane correlations of a uranium beam before SIS18 injection.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB011

Export •

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

MOPMB025

The Development of 16-Electrode Monitor for Measurement of the Multipole-Moment

quadrupole, injection, impedance, proton

140

Y. Nakanishi, A. Ichikawa, A. Minamino, K.G. Nakamura, T. Nakaya
Kyoto University, Kyoto, Japan
T. Koseki, H. Kuboki
KEK, Tokai, Ibaraki, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Funding: This work was supported by MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled 'Unification and　Development of the Neutrino Science Frontier'
In the J-PARC main ring, the beam intensity is greatly increased to 750 kW or more in near future. Even the beam intensity become higher, the beam loss must be kept at the same level as present. Aiming to make the cause of beam loss clear, we have been developing the beam monitor to measure the beam size. The quadrupole moment is related to the beam size. In principle, monitors with more than four electrodes can measure the quadrupole moment. In addition, two monitors located at the places with different beta functions can measure the emittances and beam sizes, providing the horizontal and vertical beta functions. To obtain more precise quadrupole moment and higher multipoles, we are developing the multi-electrode monitor, tentatively, with 16 electrodes. As a reference of 16-electrode monitor, two 4-electrode BPMs are investigated to measure quadrupole moments. We will present the measurement result of 4-electrode monitors and the status of the development of the 32-electrode monitor.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB025

Export •

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

MOPMB038

Development of Shoebox BPM for Xi‘an Proton Application Facility

simulation, proton, impedance, closed-orbit

175

W. Wang, X. Guan, W.-H. Huang, X.W. Wang, Z. Yang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
M.T. Qiu, Z.M. Wang
State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Shannxi, People's Republic of China

In this paper, development of the Shoebox BPM is presented which can be applied for the measurement of turn-by-turn position data, closed orbit and tune of Xi'an Proton Application Facility (XiPAF). The preliminary design of the physical dimensions including the electrode aperture, the pipe aperture and the gap between the two electrodes is performed by calculating their effects on BPM response respectively with the equivalent circuit model. Furthermore, the mechanical structure of the Shoebox BPM is optimized by CST simulation to achieve better performance. The dependency of the BPM sensitivity and zero offset on the frequency is diminished by adding one isolating ring, which decreases coupling capacitance of electrodes and compensates ground capacitance difference of the two electrodes. Finally one prototype of the Shoebox BPM has been fabricated and tested offline. Results show that relative position measurement error due to frequency dependency of sensitivity is less than 1% and absolute measurement error due to frequency dependency of zero offset is expected to be less than 0.1 mm.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB038

Export •

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

MOPMB051

Cavity BPM Performance Online Evaluation using PCA Method

cavity, experiment, electron, factory

208

Y.B. Leng, L.W. Lai, L.Y. Yu, R.X. Yuan
SSRF, Shanghai, People's Republic of China
J. Chen, Z.C. Chen
SINAP, Shanghai, People's Republic of China

Funding: NSFS 11575282
This article proposes a new test method to evaluate the performance of cavity beam position monitors using the actual beam as the exciting signal. The new method sepa-rates the signals of different modes and improves the measurement accuracy by eliminating unwanted cou-plings from other sources.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB051

Export •

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

MOPMR029

Experience with DOROS BPMs for Coupling Measurement and Correction

dipole, electronics, controls, injection

303

T. Persson, J.M. Coello de Portugal, A. Garcia-Tabares, M. Gąsior, A. Langner, T. Lefèvre, E.H. Maclean, L. Malina, J. Olexa, P.K. Skowroński, R. Tomás
CERN, Geneva, Switzerland
J. Olexa
STU, Bratislava, Slovak Republic

The Diode ORbit and OScillation System (DOROS) system is designed to provide accurate measurements of the beam position in the LHC. The oscillation part of the system, which is able to provide turn-by-turn data, is used to measure the transverse coupling. Since the system provides high resolution measurements for many turns only small excitations are needed to accurately measure the transverse coupling. In this article we present the performance the system to measure coupling and compare it to the BPMs not equipped with this system.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR029

Export •

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

MOPMR037

Analysis of Asymmetry Tolerances and Cross-coupling in Cavity BPMs

cavity, alignment, simulation, dipole

331

E. Yamakawa, S.T. Boogert, A. Lyapin, L.J. Nevay
JAI, Egham, Surrey, United Kingdom
S. Syme
FMB Oxford, Oxford, United Kingdom

Geometric asymmetries in cavity BPMs result in a coupling between horizontal and vertical signals, which complicates their usage and may affect both the dynamic range and spatial resolution of the system in both directions. Tolerances to several types of geometric asymmetries have been analysed using a 3D electromagnetic field solver (GdfidL). We report on some of the results and discussed the possible impact of the considered geometrical distortions.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR037

Export •

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

MOPMR060

C-Band Deflecting Cavity for Bunch Length Measurement of 2.5 MeV Electron Beam

cavity, vacuum, electromagnetic-fields, simulation

386

J. Jiang, H.B. Chen, J. Shi, P. Wang, L. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China

The C-band deflecting cavity designed last year is finished. In this paper, the RF measurement of the cavity is introduced. After tuning, it works well at 5.712GHz with a coupling factor degree around 1.05. And we measured the electromagnetic field with bead-pull method. The flatness of the magnetic field is around 0.9, which is not ideal but meet the requirements of the bunch length measurement. And we propose a method of tuning to make sure both frequency and field flatness.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR060

Export •

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

MOPMW002

Modeling and Simulation of Broadband RF Cavities in PSpice

cavity, simulation, impedance, storage-ring

392

J. Harzheim, D. Domont-Yankulova, H. Klingbeil, R. Königstein
TEMF, TU Darmstadt, Darmstadt, Germany
M. Frey, H. Klingbeil
GSI, Darmstadt, Germany

Barrier bucket systems are planned for the SIS100 Synchrotron (part of the future accelerator facility FAIR) and the ESR storage ring to facilitate several longitudinal beam manipulations [9] [15]. In order to achieve a single-sine gap signal of the desired amplitude and quality, effects in the linear and nonlinear region of the RF systems have to be investigated and included in the design of the overall system. Therefore, the cavities and the amplifier stages are to be modeled in PSpice. In this contribution, a cavity model will be presented. In a first step, a model for the magnetic alloy (MA) ring cores, which highly account for the properties of the cavity, has been found based on measurement data. In a second step, the future setup of the cavity is systematically created using the MA ring core models. The model of the cavity allows simulations in frequency domain as well as time domain. The results show good agreement with former measurements.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW002

Export •

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

MOPMW003

Thermal Simulation of an Energy Feedback Normal Conducting RF Cavity

cavity, simulation, operation, electron

396

M. Fakhari, K. Flöttmann, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
J. Roßbach
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
A. Yahaghi
CFEL, Hamburg, Germany

Thermal simulation has been performed for an energy feedback normal conducting RF cavity. The cavity is going to be used as a fast actuator to regulate the arrival time of the electron bunches in fs level in FLASH. By measuring the arrival time jitter of one bunch in a bunch train, the designed cavity apply a correcting accelerating or decelerating voltage to the next bunches. The input power of the cavity is provided by a solid state amplifier and will be coupled to the cavity via a loop on the body. To achieve the fs level precision of the arrival time, the cavity should be able to provide accurate accelerating voltage with a precision of 300 eV. We performed thermal simulation to find out the temperature distribution of the cavity and make sure that heating will not affect its voltage precision. The simulation results show that by using two input loops the coupling constant will vary from 4.11 to 4.13 during the operation of the cavity which effect on the bunchs' arrival time would be less than 0.25 fs. While using just one input loop can lead to an error of about 1 fs.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW003

Export •

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

MOPMW005

Design of Linac with the New Gaskets Clamping Fabrication Technique

vacuum, impedance, linac, gun

403

F. Cardelli
INFN-Roma1, Rome, Italy
D. Alesini
INFN/LNF, Frascati (Roma), Italy
M. Magi, L. Palumbo
University of Rome La Sapienza, Rome, Italy
F. Pellegrino, V. Pettinacci
INFN-Roma, Roma, Italy

Recently, a new technique for the realization of high gradient accelerating structures based on the use of gaskets without brazing processes, has been successfully tested at high power on a 1.6 cells RF gun (D. Alesini, et al, PRST 18, 02001, 2015). The new technique developed at the Laboratories of Frascati of the INFN (Italy) in the framework of the SPARC_LAB project has been also adopted for the ELI-NP RF gun. The use of the special gaskets that simultaneously guarantee the vacuum seal and a perfect RF contact allow to avoid the brazing process, strongly reducing the cost, the realization time and the risk of failure. Moreover, without copper annealing due to the brazing process, it is possible, in principle, to decrease the breakdown rate increasing, at the same time, the maximum achievable gradient. The extension of this new fabrication process to complex LINAC structures is the next step on the application of this new technique on particle accelerator. In the paper, we discuss how to extend this process to S-band and C-band Travelling Wave accelerating structures illustrating their electromagnetic design and their mechanical realization.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW005

Export •

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

MOPMW023

Optimization of the RF Cavity of a Low-energy Storage Ring for Thomson Scattering X-Ray Source

cavity, HOM, storage-ring, higher-order-mode

438

L. Ovchinnikova, V.I. Shvedunov
SINP MSU, Moscow, Russia
A. Ryabov
IHEP, Moscow Region, Russia
V.I. Shvedunov
LEA MSU, Moscow, Russia

Results of optimization of the RF cavity of a low-energy storage ring for Thomson scattering X-ray source are presented. The geometry of 714 MHz RF cavity was optimized to provide maximum shunt impedance taking into account position of higher order modes (HOMs). The number and position of cooling channels were adjusted to minimize frequency shift due to cavity thermal deformations. The waveguide coupler and frequency tuner were calculated. Special attention was paid to detailed calculations of the HOMs parameter and to study of methods to minimize their influence on the storage ring beam dynamics.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW023

Export •

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

MOPMW028

Progress on the MICE RF Module at LBNL

cavity, vacuum, operation, experiment

454

T.H. Luo, A.J. DeMello, A.R. Lambert, D. Li, T.J. Loew, S. Prestemon, S.P. Virostek, J.G. Wallig
LBNL, Berkeley, California, USA
T.G. Anderson, A.D. Bross, M.A. Palmer
Fermilab, Batavia, Illinois, USA
Y. Torun
IIT, Chicago, Illinois, USA

The international Muon Ionization Cooling Experiment aims to demonstrate the transverse cooling of a muon beam by ionization in energy absorbers. The final MICE cooling channel configuration has two RF modules, each housing a 201 MHz RF cavity used to compensate the longitudinal energy loss in the absorbers. The assembly of MICE RF Module is being carried out at LBL. In this paper we will report the recent progress on the assembly work.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW028

Export •

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

MOPMW034

Final Commissioning of the MICE RF Module Prototype with Production Couplers

cavity, vacuum, operation, Windows

474

Y. Torun, P.G. Lane
Illinois Institute of Technology, Chicago, Illlinois, USA
T.G. Anderson, M. Backfish, D.L. Bowring, A. Moretti, D.V. Neuffer, D.W. Peterson, M. Popovic, K. Yonehara
Fermilab, Batavia, Illinois, USA
B.T. Freemire
IIT, Chicago, Illinois, USA
T.L. Hart
UMiss, University, Mississippi, USA
A.V. Kochemirovskiy
University of Chicago, Chicago, Illinois, USA
T.H. Luo
LBNL, Berkeley, California, USA

Funding: Supported by the US Department of Energy Office of Science through the Muon Accelerator Program.
We report operational experience from the prototype RF module for the Muon Ionization Cooling Experiment (MICE) with final production couplers at Fermilab's MuCool Test Area. This is the last step in fully qualifying the RF modules for operation in the experiment at RAL.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW034

Export •

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

MOPMW038

Measurements of Copper RF Surface Resistance at Cryogenic Temperatures for Applications to X-Band and S-Band Accelerators

cavity, cryogenics, experiment, electron

487

A.D. Cahill, A. Fukasawa, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
G.B. Bowden, V.A. Dolgashev, M.A. Franzi, S.G. Tantawi, P.B. Welander, C. Yoneda
SLAC, Menlo Park, California, USA
J. Guo
JLab, Newport News, Virginia, USA
Y. Higashi
OIST, Onna-son, Okinawa, Japan

Funding: Funding from DOE SCGSR and DOE/SU Contract DE-AC02-76-SF00515
Recent SLAC experiments with cryogenically cooled X-Band standing wave copper accelerating cavities have shown that these structures can operate with accelerating gradients of ~250 MV/m and low breakdown rates. These results prompted us to perform systematic studies of copper rf properties at cryogenic temperatures and low rf power. We placed copper cavities into a cryostat cooled by a pulse tube cryocooler, so cavities could be cooled to 4K. We used different shapes of cavities for the X-Band and S-Band measurements. Properties of the cavities were measured using a network analyzer. We calculated rf surface resistance from measured Q0 and Q external of the cavity at temperatures from 4 K to room temperature. The results were then compared to the theory proposed by Reuter and Sondheimer. These measurements are a part of studies with the goal of reaching very high operational accelerating gradients in normal conducting rf structures.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW038

Export •

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

MOPMY005

Study of Pretuning and High Power Test of DTL Iris Waveguide Couplers Using a Single Cell Cavity

cavity, DTL, factory, simulation

522

S.W. Lee, M.S. Champion, Y.W. Kang
ORNL, Oak Ridge, Tennessee, USA

Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S.DOE.
Six drift tube linac (DTL) cavities have been operating successfully at the Spallation Neutron Source (SNS). Each cavity is fed by a tapered ridge waveguide iris input coupler and a waveguide ceramic disk window. The original couplers and cavities have been in service for more than a decade. Design optimization and tuning of the couplers were initially performed prior to installation and commissioning of the cavities. Since each DTL cavity is unique, expensive, and fully utilized for neutron production, none of the cavity structure is available as a test cavity or a spare. Maintaining spares for operations and for future system upgrade, test setup of the iris couplers for precision tuning is needed. Ideally a smaller cavity structure may be used for pretuning and RF conditioning of the iris couplers as a test cavity or a bridge waveguide. In this paper, study of using a single cell cavity for the iris tuning and conditioning is presented along with the 3D simulation results.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY005

Export •

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

MOPMY016

Quadrature Directional Coupling Method for Precise RF Power Measurement

radio-frequency, feedback, controls, experiment

549

B. Du, G. Huang, L. Lin, Y.T. Liu, Z. Zhao
USTC/NSRL, Hefei, Anhui, People's Republic of China

The directional coupler is used in the RF transmission and distribution system of accelerator, to measure the forward and backward power. Due to the finite directional isolation of the coupler (20-30dB normally), the crosstalk exists between the bi-directional coupling output signals. For the typical isolation of 26dB, if the bi-directional crosstalk signals are in- or anti- phase, the error of input or reflected power measurement is 10% in case of total reflection, whilst the error of reflected power measurement is 100% in case of VSWR 1.1. A method of quadrature directional coupling measurement is developed to solve the isolation problem. A pair of directional couplers with 90° phase difference are employed to measure the RF power. The influence of the directional crosstalk would be reduced significantly by processing the measurement data. The prototype of quadrature directional couplers is constructed to verify this method. The results showed that the measurement accuracy of quadrature coupler pair after data process is better than 2% for forward measurement, even if the error of single coupler is over 6%. The paper also analyses the error caused by non-ideal quadrature.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY016

Export •

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

MOPMY034

The Distributed Bunch Amplifier

network, electron, focusing, distributed

573

M.A. Franzi, A. Jensen, S.G. Tantawi, F. Toufexis, A.R. Vrielink
SLAC, Menlo Park, California, USA

The Distributed Bunch Amplifier (DBA) is a high efficiency RF source that utilizes a phase locked deflecting cavity and output circuit to produce a synchronous beam-wave interaction. The DBA improves on the design of previous embodiments of this technology, such as the Gyrocon*, by implementing a modern decoupled output circuit design and conical PPM beam focusing array in order to scale to higher frequencies and efficiency than previously demonstrated. Presented is a proof-of-concept S-band, 2.856 GHz, device operating with a 60 kV, 8 Amp, electron beam. Each stage of the three-cavity decoupled output circuit is optimized based on complex amplitude and shunt impedance to achieve an electronic efficiency of greater than 90%. Initial numerical analysis of this design indicates that an overall operating efficiency of greater than 70% is feasible. Detailed simulated results of the S-band model and designs to scale this technology to higher power and frequency will be discussed.
* Budker, G. I., et al. "The Gyrocon: An Efficient Relativistic High Power VHF Generator." Part. Accel. 10 (1979): 41-59.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY034

Export •

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

MOPMY035

Theoretical Analysis and Simulation of a Compact Frequency Multiplier for High Power Millimeter and Terahertz Sources

cavity, electron, cathode, space-charge

576

A.R. Vrielink, S.G. Tantawi, F. Toufexis
SLAC, Menlo Park, California, USA

As the demands on accelerating gradients and the temporal resolution of beam diagnostics and manipulation schemes grow, millimeter-wave and terahertz (THz) accelerator structures may present a natural solution. The recent advent of a radiofrequency undulator and the development of a 0.45 THz accelerator demonstrate growing interest in this frequency regime; however, growth in this area is limited by the lack of efficient, compact high power sources. We present a novel vacuum electronic device featuring an interaction between a radially bunched electron beam and azimuthally traveling waves. The use of an inward traveling radial sheet beam mitigates space charge effects at the low operating energy of 10-30 keV and allows for a high input beam current of approximately 0.5-10 A. Based on preliminary calculations, these devices could operate from 50 GHz to 250 GHz with tens of kiloWatts of output power, while the expected efficiency would scale from 60% at 80 GHz to 15% at 230 GHz. Here we present the underlying theory, possible structure design, and preliminary results from analytical calculations and simulation.
Tantawi, S. et al. Phys. Rev. Lett. 112, 164802 (April, 2014)
Nanni, E. et al. Nat. Commun. 6, 8486 (October, 2015)

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY035

Export •

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

MOPMY036

High-harmonic mm-Wave Frequency Multiplication using a Gyrocon-like Device

cavity, electron, vacuum, plasma

579

F. Toufexis, V.A. Dolgashev, M.V. Fazio, A. Jensen, S.G. Tantawi, A.R. Vrielink
SLAC, Menlo Park, California, USA
P. Borchard
Dymenso LLC, San Francisco, USA

Funding: This project was funded by U.S. Department of Energy under Contract No. DE-AC02-76SF00515, and the National Science Foundation.
Traditional linear interaction RF sources, such as Klystrons and Traveling Wave Tubes, fail to produce significant power levels at millimeter wavelengths. This is because their critical dimensions are small compared to the wavelength, and the output power scales as the square of the wavelength. We present a vacuum tube technology, where the device size is inherently larger than the operating wavelength. We designed a low–voltage mm–wave source, with an output interaction circuit based on a spherical sector cavity. This device was configured as a phased-locked frequency multiplier. We report the design and cold test results of a proof-of-principle fifth harmonic frequency multiplier with an output frequency of 57.12 GHz.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY036

Export •

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

MOPOR014

Measurements of the CERN PS Longitudinal Resistive Coupling Impedance

impedance, HOM, synchrotron, cavity

626

M. Migliorati, N. Biancacci, H. Damerau, G. Sterbini
CERN, Geneva, Switzerland
M. Migliorati
University of Rome "La Sapienza", Rome, Italy
M. Migliorati, L. Ventura
INFN-Roma1, Rome, Italy
S. Persichelli
University of Rome La Sapienza, Rome, Italy

The longitudinal coupling impedance of the CERN PS has been studied in the past years in order to better understand collective effects which could produce beam intensity limitations for the LHC Injectors Upgrade project. By measuring the incoherent quadrupole synchrotron frequency vs beam intensity, the inductive impedance was evaluated and compared with the impedance model obtained by taking into account the contribution of the most important machine devices. In this paper, we present the results of the measurements performed during a dedicated campaign, of the real part of the longitudinal coupling impedance by means of the synchronous phase shift vs beam intensity. The phase shift has been measured by using two different techniques: in one case, we injected in the machine two bunches, one used as a reference with constant intensity, and the second one changing its intensity; in the second case, more conventional, we measured the bunch position with respect to the RF signal of the 40 MHz cavities. The obtained dependence of the synchrotron phase with intensity is then related to the loss factor and the resistive coupling impedance, which is compared to the real part of the PS impedance model.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR014

Export •

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

MOPOR018

Single Bunch Instability Studies at Diamond Light Source

impedance, simulation, synchrotron, betatron

637

E. Koukovini-Platia, M. Apollonio, R. Bartolini, R.T. Fielder, I.P.S. Martin
DLS, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Single bunch instability thresholds, the associated coherent tune shifts and the bunch lengthening have been studied at Diamond light source for nominal optics. Measurements were taken under different settings of chromaticity, radio-frequency (RF) voltage and aperture of the insertion devices (IDs). The macro-particle code sbtrack was used to evaluate the instability thresholds and bunch lengthening where different impedance contributions are taken into account such as the resistive wall impedance, a broad-band resonator model and inductive impedance for the longitudinal plane. A comparison of simulation using the developed model impedance with measurements is shown for all cases.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR018

Export •

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

MOPOR025

3D Emittances Tailoring Techniques and Optimization with Space Charge for the Future CERN PS Booster Operations with Linac4

injection, emittance, simulation, linac

660

V. Forte, J.L. Abelleira, E. Benedetto, C. Bracco, M. Cieslak-Kowalska, G.P. Di Giovanni
CERN, Geneva, Switzerland

In the frame of the LIU (LHC Injectors Upgrade) project, the CERN PS Booster is going to be renovated to host a new H⁻ charge-exchange injection from the Linac4. One important feature of the new injection scheme is the possibility to tailor a wide range of 3D emittances for CERN's different users in an intensity span in the order of 5·10⁹ to 1.6·10¹³ protons per PSB ring. This paper gives an overview of 3D multi-turn injection techniques, focusing on the future LHC beams, which aim at reaching high brightness, and on highest intensity beams (ISOLDE), where losses are the main concern. Complete RF capture simulations and transverse injection maps, including space charge effects, are presented and also intended to be used during the commissioning with Linac4.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR025

Export •

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

MOPOR039

Measurement of Beam Phase at FLASH using HOMs in Accelerating Cavities

HOM, cavity, electron, simulation

686

L. Shi, R.M. Jones
UMAN, Manchester, United Kingdom
N. Baboi, L. Shi
DESY, Hamburg, Germany
N.Y. Joshi
University of Manchester, Manchester, United Kingdom

The beam phase relative to the accelerating field is of vital importance for the quality of photon beams produced in modern Free Electron Lasers based on superconducting (SC) cavities. Normally, the phase is determined by detecting the transient field induced by the beam. In this way the phase of each cavity is checked and adjusted typically every few months. In this paper, we present another means of beam phase determination, based on higher order modes (HOMs) excited in the 2nd monopole band by the beam inside the SC cavities. A circuit model of this HOM band is also presented. Various effects on the resolution have been studied. Circuit model simulations indicate the resolution is strongly dependent on the signal to noise ratio. Preliminary experimental results, based on a broadband setup, reveal an approximately 0.1o RMS resolution. These are in good agreement with simulation results. The work will pave the way for a dedicated system of beam phase monitoring, which is under development for the European XFEL. This will be the first implementation of a dedicated beam phase monitor, based on beam-excited HOMs in accelerating cavities.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR039

Export •

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

TUOBA01

Beam Commissioning of SuperKEKB

optics, vacuum, detector, septum

1019

Y. Funakoshi, T. Abe, T. Adachi, K. Akai, Y. Arimoto, K. Egawa, Y. Enomoto, J.W. Flanagan, H. Fukuma, K. Furukawa, N. Iida, H. Iinuma, H. Ikeda, T. Ishibashi, M. Iwasaki, T. Kageyama, H. Kaji, T. Kamitani, T. Kawamoto, S. Kazama, M. Kikuchi, T. Kobayashi, K. Kodama, H. Koiso, M. Masuzawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, S. Nakamura, T.T. Nakamura, H. Nakayama, T. Natsui, M. Nishiwaki, K. Ohmi, Y. Ohnishi, T. Oki, S. Sasaki, M. Satoh, Y. Seimiya, K. Shibata, M. Suetake, Y. Suetsugu, H. Sugimoto, M. Tanaka, M. Tawada, S. Terui, M. Tobiyama, S. Uehara, S. Uno, X. Wang, K. Watanabe, Y. Yano, S.I. Yoshimoto, R. Zhang, D. Zhou, X. Zhou, Z.G. Zong
KEK, Ibaraki, Japan
D. El Khechen
LAL, Orsay, France

In this report, we describe the machine operation in the first 3 months of the Phase 1 commissioning of SuperKEKB. The beam commissioning is smoothly going on. Vacuum scrubbing, the optics corrections and others are described.

Slides TUOBA01 [9.346 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOBA01

Export •

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

TUPMR055

Solid Targetry for the Isotope Production Facility at the KOMAC 100 MeV Linac

target, proton, isotope-production, shielding

1384

S.P. Yun, Y.-S. Cho, H.S. Kim, H.-J. Kwon, K.T. Seol, Y.G. Song
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
D.I. Kim
KAERI, Daejon, Republic of Korea

Funding: *This work was supported by the Ministry of Science, ICT and Future Planning of the Korean Government.
The construction of the isotope production facility was recently completed on the 100 MeV proton linac at the KOMAC (Korea multi-purpose accelerator complex). To produce the Sr-82 and Cu-67, we have prepared the solid targetry which consist of target transportation system , target cooling system and a hot-cell for remote handling. The Isotope production targets are made of RbCl pellet and stainless steel cladding. For the proton beam irradiation, the targets are transported by target drive system which consist of drive chain and guide rail by remotely. In this paper, we will report the detailed design, fabrication and operation status of the solid targetry at the KOMAC isotope production facility.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR055

Export •

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

TUPMW036

Optimizing Chromatic Coupling Measurement in the LHC

resonance, dipole, sextupole, quadrupole

1520

T. Persson, R. Tomás
CERN, Geneva, Switzerland

Optimizing chromatic coupling measurement in the LHC Chromatic coupling introduces a dependency of transverse coupling with energy. LHC is equipped with skew sextupoles to compensate the possible adverse effects of chromatic coupling. In 2012 a beam-based correction was calculated and applied successfully for the fist time. However, the method used to reconstruct the chromatic coupling was dependent on stable tunes and equal chromaticities between the horizontal and vertical planes. In this article an improved method to calculate the chromatic coupling without these constraints is presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW036

Export •

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

TUPOW022

Hybrid Electron Linac With Standing and Travelling Wave Accelerating Sections

focusing, linac, impedance, electron

1791

S.V. Matsievskiy, A.V. Bulanov, V.I. Kaminskiy, E.A. Savin, N.P. Sobenin
MEPhI, Moscow, Russia
R.Yu. Alekhanov
NRNU, Moscow, Russia

Hybrid electron linacs with standing and travelling wave accelerating sections are not well described in literature. Limited number of studies have shown that application of these systems makes it possible to develop a compact linac with high efficiency and simpler power system. Typically, these systems use well-studied bi-periodical accelerating structure (BAS) cells for a standing wave section and disc-loaded waveguides (DLW) for a traveling wave section. This paper describes the development of such system using DLW cells with magnetic coupling (DLW-M). Here BAS appears as an absorbing load connected to the DLW-M accelerating structure by rectangular waveguide allowing to have theoretical zero reflection at RF input. Such system also provides possibility of plain beam output energy adjustment. Studies of the structure were carried out using equivalent circuits methods and numerical 3D-modeling. Beam dynamics was calculated.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW022

Export •

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

TUPOW023

New 10 MeV High-power Electron Linac for Industrial Application

linac, simulation, electron, bunching

1794

S.M. Polozov, D.S. Bazyl, T.V. Bondarenko, M. Gusarova, Yu.D. Kliuchevskaia, M.V. Lalayan, V.I. Rashchikov, E.A. Savin
MEPhI, Moscow, Russia
M.I. Demsky, A.A. Eliseev, V.V. Krotov, D.E. Trifonov
CORAD Ltd., St. Petersburg, Russia
B.S. Han, W.G. Kang, H.G. Park
EB TECH Co. Ltd., Daejeon, Republic of Korea

Joint team of CORAD and MEPhI developed a new industrial accelerating structure for average beam power up to 20 kW and energy range from 7.5 to 10 MeV. The use of modern methods and codes for beam dynamics simulation, raised coupling coefficient and group velocity of SW biperiodic accelerating structure allowed to reach high pulse power utilization and obtain high efficiency. Gentle buncher provides high capturing coefficient and narrow energy spectrum. The first linear accelerator with this structure was constructed and tested in collaboration with the company EB Tech.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW023

Export •

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

TUPOW024

Compact Standing Wave Electron Linac with the Hybrid Accelerating and Power Generation Cell

electron, cavity, Windows, linac

1797

E.A. Savin, S.V. Matsievskiy, N.P. Sobenin, I.D. Sokolov
MEPhI, Moscow, Russia
A.A. Zavadtsev
Nano, Moscow, Russia

Compact electron linear accelerators for small energies are now found their place in the industrial market. Such accelerators are used for cancer treatment, cargo inspection, when one needs higher dose that X-ray source can produce, food and medicaments irradiation etc. Acceleration structures themselves are already developed very well, so the most important issue now ' is to make the whole installation with power supply, RF tracts, cooling system ' as smaller as possible to provide the structure mobility. In this article we present the development how to combine a power supply (usually it is a klystron, IOT, magnetron or solid state amplifier) with the accelerating cell itself, that can decrease installation size at least twice. No RF tracts needed, no reflected power will occur, so no circulator needed. Different power input combinations have been studied, but the smallest and the most efficient one has been manufactured for cold tests at S-band frequency range. In this structure it is very easy to vary accelerating voltage simply changing the generator beam current or the generator beam accelerating voltage.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW024

Export •

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

TUPOW040

UH-FLUX: Compact, Energy Efficient Superconducting Asymmetric Energy Recovery LINAC for Ultra-high Fluxes of X-ray and THz Radiation

cavity, HOM, electron, radiation

1847

I.V. Konoplev, A. Seryi
JAI, Oxford, United Kingdom
R. Ainsworth
Fermilab, Batavia, Illinois, USA
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

Funding: This work was supported (in part) by The Leverhulme Trust through the International Network Grant IN-2015-012.
The conventional ERLs have limited peak beam current because increasing the beam charge and repetition rate leads to appearance of the beam break-up instabilities. At this stage the highest current, from the SRF ERL, is around 300 mA. A single turn (the beam will be transported through the accelerating section, interaction point and deceleration section of the AERL only once) Asymmetric Energy Recovery LINAC (AERL) is proposed. The RF cells in different sections of the cavity are tuned in such a way that only operating mode is uniform inside all of the cells. The AERL will drive the electron beams with typical energies of 10 - 30 MeV and peak currents above 1 A, enabling the generation of high flux UV/X-rays and high power coherent THz radiation. We aim to build a copper prototype of the RF cavity for a compact AERL to study its EM properties. The final goal is to build AERL based on the superconducting RF cavity. Preliminary design for AERL's cavity has been developed and will be presented. The results of numerical and analytical models and the next steps toward the AERL operation will also be discussed.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW040

Export •

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

TUPOY014

PSI Gantry 3: Integration of a New Gantry into an Existing Proton Therapy Facility

controls, interface, proton, optics

1927

A. Koschik, C. Baumgarten, C. Bula, J.P. Duppich, A. Gerbershagen, M. Grossmann, V. Rizzoglio, J. Welte
PSI, Villigen PSI, Switzerland

Paul Scherrer Institute extends its proton therapy facility PROSCAN by a third gantry. It is delivered by Varian Medical Systems (VMS) as part of a joint research project. Gantry 3 is equipped with a cone beam CT and allows 360 degrees of rotation while occupying a 10.5 m diameter. The integration of a gantry into the existing PSI-system typically being designed for a complete Varian system is a challenging project, since also the certification is to be maintained. Especially the interfaces between the PROSCAN-control system and the one of Gantry 3 have been a major development. Gantry 3 is designed to deliver proton beam of up to 8 nA with an accuracy better than a mm, while having a high level of over-current protection. This comprises a new current monitoring unit, several levels of interlock controllers and a beam energy dependent intensity compensation concept. One challenge concerns the specified layer switching time of 200 ms, required to reduce the treatment time to enable for repainting. After technical commissioning, acceptance tests and hand over, the clinical commissioning is foreseen in the second half of 2016 with the first patient treatment in December 2016.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY014

Export •

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

TUPOY039

Studies on Electron Linear Accelerator System for Polymer Research

electron, linac, radiation, plasma

1985

E. Kongmon
IST, Chiang Mai, Thailand
N. Kangrang
Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
S. Rimjaem, J. Saisut, C. Thongbai
Chiang Mai University, Chiang Mai, Thailand
P. Wichaisirimongkol
Chiang Mai University, Science and Technology Research Institute, Chiang Mai, Thailand

This research focuses on modification of an elec-tron linear accelerator system for irradiation of natural rubber latex and polymeric materials at the Plasma and Beam Physics Research Facility, Chiang Mai Universi-ty, Thailand. This is in order to study the change of material properties due to electron beam irradiation. The main accelerator system consists of a DC thermi-onic electron gun and a short standing-wave linac. This system will be able to produce electron beams with variable energy in the range of 0.5 to 4 MeV. The linac macro pulse frequency is adjustable within the range of 20 to 1000 Hz. The macro pulse duration is 4 μs. The electron pulse current can be varied from 10 to 100 mA. This lead to the electron dose of about 0.44 to 4.4 Gy-m2/min. In this paper, overview of the accelera-tor and the irradiation system is presented. Results of low-level RF measurements of the accelerating struc-ture are also reported and discussed.
This work has been supported by the CMU Junior Research Fellowship Program, the Department of Physics and Material Science, Faculty of science, Chiang Mai University.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY039

Export •

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

TUPOY041

A Metal-Dielectric Micro-Linac for Radiography Source Replacement

focusing, linac, electron, vacuum

1992

A.V. Smirnov, S. Boucher, S.V. Kutsaev
RadiaBeam Systems, Santa Monica, California, USA
R.B. Agustsson, R.D.B. Berry, J.J. Hartzell, J. McNevin, A.Y. Murokh
RadiaBeam, Santa Monica, California, USA
G. Leyh
LOD, Brisbane, USA
E.A. Savin
MEPhI, Moscow, Russia

Funding: * US Department of Energy Contract # DE-SC0011370
To improve public security and prevent the diversion of radioactive material for Radiation Dispersion Devices, RadiaBeam is developing an inexpensive, portable, easy-to-manufacture linac structure to allow effective capture of a ~13 keV electron beam injected from a conventional electron gun and acceleration to a final energy of ~ 1 MeV. The bremsstrahlung X-rays produced by the electron beam on a high-Z converter at the end of the linac will match the penetration and dose rate of a typical ~100 Ci or more Ir-192 source. The tubular Disk-and-Ring structure under development consists of metal and dielectric elements that reduce or even eliminate multi-cell, multi-step brazing. This may allow significant simplification of the fabrication process to enable inexpensive mass-production required for replacement of the ~55,000 radionuclide sources in the US

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY041

Export •

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

WEOAA01

Transverse Emittance Exchange for Improved Injection Efficiency

emittance, resonance, synchrotron, injection

2028

P. Kuske, F. Kramer
HZB, Berlin, Germany

In most cases beam is injected into electron storage rings in the horizontal plane and off-axis. The larger the horizontal emittance of the injected beam the larger the acceptance of the ring has to be. The injected beam is usually delivered by a synchrotron. In case the vertical acceptance of the ring is sufficiently large one can take advantage of the small vertical emittance reached in well aligned and tuned synchrotrons since the transverse emit-tances can be exchanged with the help of skew quadru-pole magnets. A few possible processes will be discussed: emittance exchange with static magnets in the transfer line between synchrotron and ring or emittance exchange in the synchrotron shortly before extraction with time dependent magnets. This could be a suddenly switched-on normal or skew quadrupole magnet or skew quadru-pole fields oscillating at a frequency fulfilling the reso-nance condition. Estimates for these magnets and their design will be given.

Slides WEOAA01 [0.852 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA01

Export •

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

WEPMB011

ESS Medium and High Beta Cavity Prototypes

cavity, HOM, cryomodule, interface

2138

P. Michelato, A. Bellandi, M. Bertucci, A. Bignami, A. Bosotti, J.F. Chen, L. Monaco, R. Paparella, P. Pierini, D. Sertore
INFN/LASA, Segrate (MI), Italy
C.G. Maiano
DESY, Hamburg, Germany
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
S. Pirani
ESS, Lund, Sweden

In the framework of the ESS activity in progress at INFN-LASA, we are designing and developing 704.42 MHz Medium (β=0.67) and High (β=0.86) beta prototype cavities plug compatible with the ESS cryomodule design. The cells of one Medium and one High beta cavity are fabricated with high quality CBMM Large Grain Niobium (480 mm dia. Ingot, RRR=300, sliced by Heraeus) while a Medium beta cavity is done with Fine Grain material for comparison. The prototype cavities will be produced by the firm Ettore Zanon S.p.A. under the supervision of INFN - LASA group.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB011

Export •

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

WEPMB060

Modifications to the Pump Out Box to Lower the Qext of Diamond SCRF Cavities

cavity, operation, simulation, electron

2251

S.A. Pande, C. Christou, P. Gu
DLS, Oxfordshire, United Kingdom
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

Diamond's CESR-B cavities are iris coupled and have fixed Qext. For reliability, the cavities are operated at lower voltages. This results in the optimum condition for beam loading being satisfied at a much lower power typically about 100 kW. For operation at 300 mA with two cavities, the RF power needed per system exceeds 200 kW. Consequently, the cavities need to be operated under-coupled. To lower the Qext and move the optimum operating point nearer to 200kW, 3 stub tuners are used in the waveguide feed line. The difference in the height of the coupling waveguide on cavity and that of the vacuum side waveguide on the window assembly results in a step transition which affects the Qext. The present window/step location results in Qext higher than that without the window. The Qext can be lowered by re-locating the RF window or by shifting the step change in the waveguide cross-section from its present location. This needs modification to the Pump Out box. The pros and cons of the proposed modification to the pump out box in terms of standing waves and multipacting characteristics studied with CST Studio are discussed in this paper.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB060

Export •

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

WEPMW015

Evaluation and Compensation of Detector Solenoid Effects in the JLEIC

solenoid, detector, ion, quadrupole

2454

G.H. Wei, F. Lin, V.S. Morozov, F.C. Pilat, Y. Zhang
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357. Work supported also by the U.S. DOE Contract DE-AC02-76SF00515.
The JLEIC detector solenoid has a strong 3 T field in the IR area, and its tails extend over a range of several meters. One of the main effects of the solenoid field is coupling of the horizontal and vertical betatron motions which must be corrected in order to preserve the dynamical stability and beam spot size match at the IP. Additional effects include influence on the orbit and dispersion caused by the angle between the solenoid axis and the beam orbit. Meanwhile it affects ion polarization breaking the figure-8 spin symmetry. Crab dynamics further complicates the picture. All of these effects have to be compensated or accounted for. The proposed correction system is equivalent to the Rotating Frame Method. However, it does not involve physical rotation of elements. It provides local compensation of the solenoid effects independently for each side of the IR. It includes skew quadrupoles, dipole correctors and anti-solenoids to cancel perturbations to the orbit and linear optics. The skew quadrupoles and FFQ together generate an effect equivalent to adjustable rotation angle to do the decoupling task. Details of all of the correction systems are presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW015

Export •

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

WEPMW029

Simulation of Heavy-Ion Beam Losses with the SixTrack-FLUKA Active Coupling

ion, heavy-ion, simulation, collimation

2490

P.D. Hermes, R. Bruce, F. Cerutti, A. Ferrari, J.M. Jowett, A. Lechner, A. Mereghetti, D. Mirarchi, P.G. Ortega, S. Redaelli, B. Salvachua, E. Skordis, G. Valentino, V. Vlachoudis
CERN, Geneva, Switzerland

Funding: Work suppported by the Wolfgang Gentner Programme of the German BMBF
The LHC heavy-ion program aims to further increase the stored ion beam energy, putting high demands on the LHC collimation system. Accurate simulations of the ion collimation efficiency are crucial to validate the feasibility of new proposed configurations and beam parameters. In this paper we present a generalized framework of the SixTrack-FLUKA coupling to simulate the fragmentation of heavy-ions in the collimators and their motion in the LHC lattice. We compare heavy-ion loss maps simulated on the basis of this framework with the loss distributions measured during heavy-ion operation in 2011 and 2015.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW029

Export •

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

WEPMY037

Cold Model Cavity for 20-K Cryocooled C-band Photocathode RF Gun

simulation, cavity, gun, impedance

2635

T. Tanaka, M. Inagaki, R. Nagashima, K. Nakao, K. Nogami, T. Sakai, K. Takatsuka
LEBRA, Funabashi, Japan
M.K. Fukuda, T. Takatomi, N. Terunuma, J. Urakawa, M. Yoshida
KEK, Ibaraki, Japan
D. Satoh
TIT, Tokyo, Japan

Funding: Work supported by the Photon and Quantum Basic Research Coordinated Development Program of the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT).
A cryocooled 2.6-cell C-band photocathode RF gun is under development at Nihon University in collaboration with KEK. The RF characteristics of a pillbox-type 2.6-cell C-band RF cavity at 20 K were in agreement with the theoretical predictions. The result of the cold test for a cavity with the input coupler confirmed the same characteristics. Based on these results a refined cold model of the 20-K cryocooled photocathode RF gun has been designed using SUPERFISH and CST-STUDIO. The separation between the TM01 pi and the TM01 half-pi modes has been increased from 20 MHz to 52 MHz by extending the diameter of the cavity iris and reducing the disk thickness. The 2.6-cell structure has been modified from pillbox to ellipsoid-like type. The end-plate of the 0.6-cell cavity has a center hole for bead-pull measurements of the on-axis electric filed through the entire structure. Mounting of a photocathode assembly in the end-plate has not been considered, since the purpose is solely to measure the low-power and low-temperature RF characteristics. A new design for the input coupler has been employed. The cavity will be completed early in 2016.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY037

Export •

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

WEPMY038

Optimization of C-band RF Input Coupler as a Mode Converter for 20-K Cryocooled Photocathode RF Gun

cavity, gun, simulation, insertion

2638

T. Tanaka, M. Inagaki, R. Nagashima, K. Nakao, K. Nogami, T. Sakai, K. Takatsuka
LEBRA, Funabashi, Japan
M.K. Fukuda, T. Takatomi, N. Terunuma, J. Urakawa, M. Yoshida
KEK, Ibaraki, Japan
D. Satoh
TIT, Tokyo, Japan

Funding: Work supported by the Photon and Quantum Basic Research Coordinated Development Program of the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT).
Development of a cryocooled 2.6-cell C-band photocathode RF gun has been conducted at Nihon University in collaboration with KEK. An RF mode converter from square TE10 to circular TM01 mode has been employed as an RF input coupler that has a coupling coefficient of approximately 20 at 20 K to the 2.6-cell accelerating structure. In the previous design, the circular waveguide in the mode converter formed part of the accelerating cavity. After the cold test of the cavity completed in 2014, the coupler design was modified to work as a pure mode converter with a VSWR of 1 at 5712 MHz. From the design simulation using CST-STUDIO, the insertion loss in the converter is 0.2 %. The TM010 and TM011 modes excited in the circular waveguide were separated by several ten MHz from the accelerating frequency. The simulation has suggested that the amplitude of the transverse electric filed on the axis in the circular waveguide is reduced to approximately 2 % of that in the longitudinal direction.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY038

Export •

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

WEPOR008

Development of a High Resolution Beam Position Monitor for NSRRC VUV/THz FEL

cavity, dipole, electron, simulation

2680

P.J. Kung, K.C. Leou
NTHU, Hsinchu, Taiwan
W.K. Lau, A.P. Lee
NSRRC, Hsinchu, Taiwan

Beam position monitors (BPM) have been widely used on linear colliders and free electron lasers for beam-based alignment and feedback systems. A laser driven photo-injector system has been constructed in NSRRC. This injector has the capability to deliver short relativistic electron beam at high peak current for novel light source R&D. A 2.4 GHz BPM that can be used for high precision beam position measurement has been designed. The BPM were modified to separate frequency between the horizontal and vertical dipole signals, as well as a reduction of the monopole signal. The design has been simulated by CST. A prototype has been built for verification of theoretical predictions. Microwave bench measurement has been made to compare with the computer simulation results. The progress of our work will be presented in this paper.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR008

Export •

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

THPMB006

Unclosed Lattice Dispersions as a Tool for Partial Removal of Transverse to Longitudinal Beam Correlations

emittance, lattice, synchrotron, optics

3229

V. Balandin, W. Decking, N. Golubeva
DESY, Hamburg, Germany

We show how to choose unclosed lattice dispersions in order to zero either linear beam dispersions (linear correlations between energy of particles and their transverse positions and momenta) or linear beam tilts (linear correlations between longitudinal positions of particles and their transverse coordinates). Besides that, we prove that while removal of beam dispersions always leads to reduction of transverse projected emittances, zeroing of beam tilts cannot guarantee it.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB006

Export •

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

THPMB049

Optics Calibration During Commissioning of the Taiwan Photon Source

optics, lattice, quadrupole, emittance

3357

F.H. Tseng, C.H. Chen, J.Y. Chen, M.-S. Chiu, C.-C. Kuo, Y.-C. Liu, H.-J. Tsai
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source is a 3-GeV low emittance synchrotron light machine with circumference of 518.4m. The lattice is with 24-cell DBA structure and emittance is 1.6 nm-rad. During the commissioning in the past year, we employed MATLAB-based high level applications to calibrate the optical functions in three different operation lattice modes. In particular, we used LOCO (Linear Optics from Closed Orbit) to restore the machine optical functions and reduce emittance coupling ratio. The beam-based alignment (BBA) measurements as well as BPM and corrector errors were identified.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB049

Export •

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

THPMB050

The Commmissioning of Phase-I Insertion Devices in TPS

storage-ring, lattice, undulator, radiation

3360

M.-S. Chiu, C.H. Chang, C.H. Chen, J. Chen, J.Y. Chen, Y.-S. Cheng, P.C. Chiu, P.J. Chou, T.Y. Chung, S. Fann, K.H. Hu, C.H. Huang, J.C. Huang, C.-S. Hwang, C.-C. Kuo, T.Y. Lee, C.C. Liang, Y.-C. Liu, H.-J. Tsai, F.H. Tseng, C.Y. Wu
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is a low-emittance 3-GeV light source at Natioal Synchrotron Radiation Research Center, next to the Taiwan Light source (1.5 GeV). On March 26, 2015, the TPS storage ring with two 5-cell PETRA cavities has successfully operated in 100 mA in top-up mode without the installation of insertion devices (IDs). To reach the design goal of 500 mA, the machine was shut down for 5 months to replace PETRA cavitites with superconducting RF (SRF) cavities and to install 10 IDs: 7 in-vacuum undulators (IU) and 3 elliptically polarized undulators (EPU). The commissioning of TPS storage ring with SRF cavities and IDs began in Sep. 2015. In this paper, we present our results and proceedures of ID commissioning.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB050

Export •

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

THPMR038

Non-Linear Errors in the Experimental Insertions of the LHC

insertion, multipole, dipole, dynamic-aperture

3472

E.H. Maclean, F.S. Carlier, M. Giovannozzi, A. Langner, S. Mönig, T. Persson, P.K. Skowroński, R. Tomás
CERN, Geneva, Switzerland

Correction of nonlinear magnetic errors in low-β insertions can be of critical significance for the operation of a collider. This is expected to be of particular relevance to LHC Run II and the HL-LHC upgrade, as well as to future colliders such as the FCC. Current correction strategies for these accelerators have assumed it will be possible to calculate optimized local corrections through the insertions using a magnetic model of the errors. To test this assumption the nonlinear errors in the LHC experimental insertions have been examined via feed-down and amplitude detuning. It will be shown that while in some cases the magnetic measurements provide a sufficient description of the errors, in others large discrepancies exist which will require beam-based correction techniques.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR038

Export •

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

THPMR040

Local Optics Corrections in the HL-LHC IR

optics, quadrupole, controls, simulation

3480

J.M. Coello de Portugal, F.S. Carlier, A. Garcia-Tabares, A. Langner, E.H. Maclean, L. Malina, T. Persson, P.K. Skowroński, R. Tomás
CERN, Geneva, Switzerland

For the high luminosity upgrade of the LHC optics correction in the interaction regions is expected to be challenged by the very low β^* and the sizable expected quadrupolar errors in the triplet. This paper addresses the performance and limitations of the segment-by-segment technique to correct quadrupolar and skew quadrupolar errors in the HL-LHC IR via computer simulations. Required improvements to this technique and possible combinations with other correction approaches are also presented including experimental tests in the current LHC IR.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR040

Export •

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

THPMR048

Analysis of Nonlinear Effects for IDs at the SPS Storage Ring

electron, storage-ring, injection, quadrupole

3512

S. Krainara, P. Klysubun, S. Kongtawong, T. Pulampong, P. Sudmuang, P. Sunwong
SLRI, Nakhon Ratchasima, Thailand

Funding: Synchrotron Light Research Institute (Public Organization)
To generate intense and high energy synchrotron radiation at the Siam Photon Source (SPS) 1.2 GeV storage ring, two insertion devices (IDs), namely, a 2.2 T hybrid multipole wiggler (MPW) and a 6.5 T superconducting wavelength shifter (SWLS), have been installed and operated since 2013. The angular kicks due to the nonlinear effects generated by the IDs represented by kick maps were used in our analysis. The optics distortion was compared to the ones obtained from calculation using hard-edge model and measurement results. In order to investigate the effects of IDs on the beam dynamics, Frequency Map Analysis (FMA) was employed. The effects of the IDs and their compensation are presented herewith.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR048

Export •

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

THPMW030

Studies of Impedance-related Improvements of the SPS Injection Kicker System

kicker, impedance, simulation, vacuum

3611

M.J. Barnes, A. Adraktas, M.S. Beck, G. Bregliozzi, H.A. Day, L. Ducimetière, J.A. Ferreira Somoza, B. Goddard, T. Kramer, C. Pasquino, G. Rumolo, B. Salvant, L. Sermeus, J.A. Uythoven, L. Vega Cid, W.J.M. Weterings, C. Zannini
CERN, Geneva, Switzerland
F.M. Velotti
EPFL, Lausanne, Switzerland

The injection kicker system for the SPS consists of sixteen magnets housed in a total of four vacuum tanks. The kicker magnets in one tank have recently limited operation of the SPS with high-intensity beam: this is due to both beam induced heating in the ferrite yoke of the kicker magnets and abnormally high pressure in the vacuum tank. Furthermore, operation with the higher intensity beams needed in the future for HL-LHC is expected to exacerbate these problems. Hence studies of the longitudinal beam coupling impedance of the kicker magnets have been carried out to investigate effective methods to shield the ferrite yoke from the circulating beam. The shielding must not compromise the field quality or high voltage behaviour of the kicker magnets and should not significantly reduce the beam aperture: results of these studies, together with measurements, are presented. In addition results of tests to identify the causes of abnormal outgassing are presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW030

Export •

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

THPMW031

Current and Future Beam Thermal Behaviour of the LHC Injection Kicker Magnet

impedance, kicker, injection, simulation

3615

H.A. Day, M.J. Barnes, L. Ducimetière, L. Vega Cid, W.J.M. Weterings
CERN, Geneva, Switzerland

During Run 1 of the LHC the injection kicker magnets caused occasional operational delays due to beam induced heating with high bunch intensity and short bunch lengths. Significant upgrades were carried out to the injection kicker magnets during long shutdown 1, including a new design of beam screen to reduce the beam induced heating. Nevertheless these kicker magnets may limit the performance of HL-LHC unless additional, mitigating, measures are taken. Hence extensive simulations have been carried out to predict the distribution of the beam induced power deposition within the magnet and detailed thermal analyses carried out to predict the temperature profiles. To benchmark the simulations the predicted temperatures are compared with observables in the LHC. This paper reports on observations of the thermal behaviour of the magnet during run 2 of the LHC, with 25ns beam. In addition the measurement data is used to extrapolate temperature rise for the beam parameters expected for high-luminosity LHC.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW031

Export •

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

THPMW038

Prototyping of the ALS-U Fast Kickers

kicker, impedance, vacuum, injection

3637

G.C. Pappas, S. De Santis, J.-Y. Jung, T.H. Luo, C. Steier, C.A. Swenson, W.L. Waldron
LBNL, Berkeley, California, USA

Prototyping of major components for the ALS-U kickers is in progress. A tapered stripline kicker has been built for installation and testing in the ALS, and multiple modulator options to meet the fast rise time required for swap out injection have been considered. High voltage feedthroughs that are matched into the multi GHz range are also being studied.
* Pappas et al., "Fast Kicker Systems for ALS-U", Proc. of IPAC'14, Dresden, Germany, MOPME083.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW038

Export •

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

THPMY009

Coaxial Wire Method Adapted to Weakly Coupled Resonator Mode for LHC RF Fingers Evaluation

resonance, impedance, cavity, vacuum

3670

C. Vollinger, F. Caspers, T. Kaltenbacher
CERN, Geneva, Switzerland

In high intensity particle accelerators, RF contact fingers are commonly used to carry the beam induced image current. In addition, they reduce beam impedance by shielding the outer bellows required to compensate mechanical displacements between components. In order to assess the resulting beam impedance from a specific bellow/RF finger configuration, RF measurements are routinely carried out. During these measurements, it was observed that cavity modes in the volume between the fingers and the bellow undulation arise. These resonances occur at significantly higher frequencies than the expected frequency range of interest. Due to their broadband nature, the tails of the imaginary part of these resonances reach into the lower frequency range of interest where it contributes to the beam coupling impedance of the device. For proper evaluation of this contribution, a time domain delay technique in TDT (time domain transmissiometry) was used in order to overcome shortcomings that arise if the classical coaxial wire method is applied to these structures. We present the theory of our method and discuss it in view of the data measured on deformable fingers that were studied for the LHC.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY009

Export •

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

THPMY033

Vibration Evaluation for Deionized Water Pumps in TPS

operation, booster, alignment, status

3731

Y.-H. Liu, C.S. Chen, Y.-C. Chung
NSRRC, Hsinchu, Taiwan

The purpose of this paper is to evaluate the vibration level and spectrum for TPS deionized water pumps. The utility systems started to operate from the beginning of 2014, some of deionized water pumps produced higher vibration level and noise during operation. The possibly reason could be not appropriated installation and commission test. In order to figure out the status of these deionized water pumps, the vibration analysis become needed. After vibration test, the booster(BO) and copper(CU) deionized water pump systems generate higher vibration level. According to the vibration test results, the pump is repair and maintain. Although there is some problems for TPS deionized water pumps, the vibration test is still one important way to maintain utility systems. The utility systems could prevent malfunction through regular vibration inspection.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY033

Export •

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

THPOR007

Optics Measurements and Corrections at the Early Commissioning of SuperKEKB

sextupole, optics, quadrupole, emittance

3782

Y. Ohnishi, Y. Funakoshi, H. Koiso, A. Morita, K. Ohmi, K. Oide, H. Sugimoto, D. Zhou
KEK, Ibaraki, Japan
M.E. Biagini, M. Boscolo, S. Guiducci
INFN/LNF, Frascati (Roma), Italy
N. Carmignani, S.M. Liuzzo
ESRF, Grenoble, France

We present experimental results of measurements and corrections of the optics at the early Phase-1 commissioning of SuperKEKB which is a positron-electron collider built to achieve the target luminosity of 8x10³⁵ cm^-2s^-1. We have three stages; the Phase-1 is the commissioning of the machine without the final focus magnets and detector solenoid(no collision); the collision with the final focus system and the Belle II detector will be performed at the Phase-2 and Phase-3. The strategy for the luminosity upgrade is a novel "nano-beam'' scheme found elsewhere*. In order to achieve the target luminosity, the vertical emittance has to be reduced by corrections of machine error measured by orbit responses. The vertical emittance should be achieved to be less than 6 pm(0.2 % coupling) during the Phase-1 by fully utilizing correction tools of skew quadrupole-like coils wound on sextupole magnets and power supplies for each correction coil in quadrupole magnets. In addition to the linear optics, the optics for off-momentum particles is also studied to understand a dynamic aperture affects the Touschek lifetime.
* "SuperB Conceptual Design Report", INFN/AE-07/2, SLAV-R-856, LAL 07-15, (2007).

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR007

Export •

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

THPOR029

First Start-to-End BBA Results in the CLIC RTML

emittance, sextupole, quadrupole, alignment

3841

Y. Han, L. Ma
SDU, Shandong, People's Republic of China
A. Latina, D. Schulte
CERN, Geneva, Switzerland

CLIC is a design study for a 3 TeV linear collider designed for the high-energy frontier in the post-LHC era. The Ring To Main Linac (RTML) part of CLIC is a long section that must transport the electron and the positron bunches through more than 20 km of beamlines, with minimal emittance growth. A sequence of three beam-based alignment (BBA) techniques must be used to transport the beam: one-to-one correction (OTO), dispersion-free steering (DFS), and sextupole correction (SCS). The performance of the whole correction procedure is tested under several realistic imperfections: magnets position offsets, magnets rotation errors, magnets strength errors and emittance measurement errors. The results show that the emittance growth budgets can be met both in the horizontal and vertical planes.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR029

Export •

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

THPOR043

High Power Test of X-band Single Cell HOM-free Choke-mode Damped Accelerating Structure made by Tsinghua University

cavity, operation, vacuum, HOM

3881

X.W. Wu, H.B. Chen, J. Shi
TUB, Beijing, People's Republic of China
T. Abe, T. Higo
KEK, Ibaraki, Japan
W. Wuensch, H. Zha
CERN, Geneva, Switzerland

As an alternative design for CLIC main accelerating structures, X-band choke-mode damped structures had been studied for several years. However, the performance of choke-mode cavity under high power is still in lack of research. Two standing wave single cell choke-mode damped accelerating structures with different choke dimensions which are working at 11.424 GHz were designed, manufactured and bench tested by accelerator group in Tsinghua University. High power test was carried out on it to study the breakdown phenomenon in high gradient. A single cell structure without choke which almost has the same inner dimension as choke-mode cavity will also be tested to make a comparison and study how the choke affects high-gradient properties.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR043

Export •

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

THPOW001

Design of a 4.6-Cell RF Gun for the PHIL accelerator at LAL

gun, emittance, cavity, impedance

3922

P. Chen, C. Bruni, S. Chancé, L. Garolfi, A. Gonnin, P. Lepercq, T. Vinatier
LAL, Orsay, France

A photo-injector with 4.6-cell and resonate frequency of 2.998 GHz has been designed and studied to replace the 2.5-cell RF gun + booster association. The cavity iris shape and dimensions were simulated systematically to optimize the shunt impedance. In this study, electron beam reaches to 9.7 MeV with a moderate peak accelerat-ing gradient of 80 MV/m. Considering a beam charge of 1 nC/bunch, average transverse emittance of ~ 5.9 πmm mrad and energy spread of ~ 0.8% can be obtained at the exit of the gun. The RF input power is only 10.2 MW due to the high shunt impedance. Asymmetry of the electric field due to the coupling port has also been studied using 3D codes for RF and beam dynamics calculations. We will present the RF design and beam calculations results.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW001

Export •

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

THPOW002

Electromagnetic, Thermal, and Structural Analysis of a THOMX RF Gun Using ANSYS

gun, cavity, electron, simulation

3925

M. El Khaldi, J. Bonis, A. Camara, L. Garolfi, A. Gonnin
LAL, Orsay, France

Photocathode RF guns are used in the first stage of electron beam generation and acceleration. The RF gun of THOMX is a 2.5 cell standing wave copper cavity with resonance frequency of 2998.55 MHz at 30 °C under vacuum. The metal photocathode such as copper or magnesium is inserted into the backplane of the cavity. Due to high repetition rates up to 50 Hz with the average dissipated power into the internal surfaces up to 1.5 kW, causing a heating and deformation of the cavity shape. Therefore, the cooling system of the device has to be well designed to take under control the deformations of the structure, providing a temperature increase as small and uniform as possible. For this purpose a fully coupled electromagnetic-thermal-structural finite element analysis on this gun has been performed with Ansys workbench. Numerical results show that the gun could operate at 3 μs RF pulse length and 50 Hz repetition rate with an average dissipated power of 1.5 kW. The gun average temperature is around 30 °C while the incoming water temperature is around 24°C. Internal speed of water is 2.5 m/s which corresponds to 15 l/min for the incoming water. The total pressure drop is around 0.4 bar

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW002

Export •

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

THPOW028

Automated Design for Standing Wave Electron Photoguns: TOPGUN RF Design

gun, toolkit, simulation, cavity

3999

A.D. Cahill
UCLA, Los Angeles, California, USA
M. Dal Forno, V.A. Dolgashev
SLAC, Menlo Park, California, USA

Funding: DOE SCGSR and DOE/SU Contract DE-AC02-76-SF00515
Systematic design of RF photoguns involves multiple RF simulations in conjunction with beam dynamic simulations. RF simulations include tuning gun frequency, matching the gun to the feeding RF circuit, balancing the on axis electric fields between gun cells, minimizing surface electric and magnetic fields and power consumption, and optimizing separation of resonant mode frequencies. We created a tool that allows this multiple parameter optimization to be done automatically. We used SUPERFISH to accomplish the RF simulations. We present an example of the rf photogun TOPGUN design using these tools.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW028

Export •

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