IPAC2016 - List of Keywords (experiment)

Paper	Title	Other Keywords	Page
MOPMB002	First Measurements of Coherent Smith-Purcell Radiation in the SOLEIL Linac	detector, linac, radiation, operation	69
	N. Delerue, J. Barros, S. Jenzer, V. Khodnevych, M.S. Malovytsia LAL, Orsay, France N. Hubert, M. Labat SOLEIL, Gif-sur-Yvette, France V. Khodnevych National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine M.S. Malovytsia KhNU, Kharkov, Ukraine
	Funding: The authors are grateful for the funding received from the French ANR (contract ANR-12-JS05-0003-01). An experiment to measure the Coherent Smith-Purcell radiation has been installed in the SOLEIL Linac. Its aim is to produce a map of Smith-Purcell radiation emissions in several planes and compare it with theoretical predictions. Coherent Smith Purcell radiation is produced when a grating is brought close from a sufficiently short charged particles beam. The experiment consist of two detectors with 5 degrees of freedom. These two detectors can be moved around the emission point to measure the intensity of the radiation at different locations. Radiation maps are recorded parasitically by moving the detectors around during normal linac operations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB002
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MOPMB004	Comparison of the Smith-purcell Radiation Yield for Different Models	radiation, electron, simulation, detector	75
	M.S. Malovytsia, N. Delerue LAL, Orsay, France M.S. Malovytsia KhNU, Kharkov, Ukraine
	Funding: The authors are grateful for the funding received from the French ANR (contract ANR-12-JS05-0003-01) and the IDEATE International Associated Laboratory (LIA) France-Ukraine. Smith-Purcell radiation is used in several applications including the measurement of the longitudinal profile of electron bunches. A correct reconstruction of such profile requires a good understanding of the underlying model. We have compared the leading models of Smith-Purcell radiation and shown that they are in agreement within the experimental errors.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB004
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MOPMB007	Diamond Sensor Resolution in Simultaneous Detection of 1,2,3 Electrons at the PHIL Photoinjector Facility at LAL	electron, detector, simulation, target	84
	V. Kubytskyi, P. Bambade, S. Barsuk LAL, Orsay, France O.A. Bezshyyko, V. Krylov, V. Rodin National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine
	In this paper, we present experimental and numerical studies of the signals from the Poisson-like distributions resulting from electrons incident on a diamond sensor placed near the exit of the PHIL photoinjector facility at LAL. The experiments were performed at the newly commissioned Low Energy Electron TECHnology (LEETECH) platform at PHIL. Bunches of 10x9 electrons are first generated and accelerated to 3.5 MeV by PHIL. The electrons are then filtered in LEETECH by a system of collimators, using a dipole magnet for momentum selection. The diamond sensor is located immediately after the output collimator to collect electrons in the range 2.5-3 MeV. We show that with standard scCVD diamonds of 500 micrometers thickness, the energy losses from the first three MIP (minimum ionizing particle) electrons are clearly resolved. We did not observe distinguishable peaks in cases when a significant fraction of the incident electrons had energies below a MIP. The described technique can be used as complementary approach for calibration of diamond detectors as well as to diagnose and help control accelerated beams in a regime down to a few particles.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB007
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MOPMB029	Development Status of Linear Focal Cherenkov Ring Camera	electron, vacuum, laser, photon	152
	K. Nanbu, T. Abe, H. Hama, F. Hinode, S. Kashiwagi, T. Muto, I. Nagasawa, H. Saito, K. Takahashi, C. Tokoku Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	Linear focal Cherenkov ring camera (LFC-Camera) has been developed for single shot measurement of longitudinal phase space distribution of quasi-relativistic electron beam, where the electron's velocity still depends on its energy. The LFC-camera employs velocity dependence of opening angle of Cherenkov light produced by electron beam to observe its energy (momentum) distribution. Since the Cherenkov light contains the time information if the radiator medium is thin enough, we can get the longitudinal phase space distribution measuring both time and energy spectra simultaneously using a streak camera. We employ a thin silica aerogel with water-free hydrophobic treatment as Cherenkov radiator. We have evaluated characteristics of the silica aerogel radiator, and demonstration of the LFC-camera at a beam diagnosis section of t-ATCS is being proceeded.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB029
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MOPMB030	Development of an EO Sampling Method for THz Pulse Detection	laser, radiation, polarization, electron	155
	T. Toida, M. Washio, R. Yanagisawa Waseda University, Tokyo, Japan K. Sakaue Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan
	We have been studying an S-band Cs-Te photo-cathode rf gun at Waseda Univ. The high quality electron beam produced by the rf gun is used to generate a high-power coherent terahertz pulse via Cherenkov radiation. This terahertz pulse can be applied to terahertz imaging and material analysis. As a preliminary step towards material analysis, we conducted experiments on terahertz time domain spectroscopy by EO sampling method to reveal major parameters of the terahertz pulse such as the pulse form and the spectrum. EO sampling method has high frequency response and suitable for high peak power terahertz pulses. In terahertz time domain spectroscopy, the duration of the probe pulse needs to be much faster than that of the terahertz pulse. Therefore, we developed a mode locked Yb-fiber laser based on nonlinear polarization rotation as a reliable and cost-effective ultra-fast probe light source. The laser generates 3.80 ps chirped pulses which are compressed to 213 fs with a grating pair. In this conference, we will report the performance of the Yb-fiber laser and results of EO sampling experiments.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB030
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MOPMB048	Bunch Length Measurement at Bunch by Bunch in Harmonics Method at Shanghai SSRF Storage Ring	injection, storage-ring, electron, synchrotron-radiation	199
	L.W. Duan, Y.B. Leng, R.X. Yuan SINAP, Shanghai, People's Republic of China N. Zhang SSRF, Shanghai, People's Republic of China
	Harmonics method in frequency domain is an effective and inexpensive bunch length measurement method. With advances in technology, it is possible to do bunch length measurement at bunch by bunch using electronic method. We design and make an electronic system to realize metering at bunch by bunch, and believe it has reasonable bunch length resolution. All selected harmonic signals will be mixed down to 500 MHz and digitized at bunch-by-bunch rate by a multi-channel DBPM processor. The primary beam experiment results will be presented and discussed in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB048
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MOPMB050	Design of Ultra-wideband Amplifier in RF Front End for Bunch-by-bunch Measurement	power-supply, simulation, impedance, synchrotron-radiation	205
	Y. Yang, Y.B. Leng, Y.B. Yan SSRF, Shanghai, People's Republic of China
	RF front end is one of the key technologies in beam diagnosis, especially in bunch-by-bunch measurement at storage ring. This paper gives the design of ultra-wideband amplifier in RF front end for bunch-by-bunch measurement at SSRF. Simulation have been done to verify the performance of this design.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB050
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MOPMB051	Cavity BPM Performance Online Evaluation using PCA Method	cavity, electron, factory, coupling	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
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MOPMB054	A High Sensitivity Faraday Cup for Ultrashort Electron Bunches	electron, simulation, gun, laser	214
	S. Setiniyaz, I.H. Baek, B.A. Gudkov, B. Han, K.H. Jang, Y.U. Jeong, H.W. Kim, S.V. Miginsky, J.H. Nam, S. Park, N. Vinokurov KAERI, Daejon, Republic of Korea S.V. Miginsky, N. Vinokurov BINP SB RAS, Novosibirsk, Russia
	The UED (Ultrafast Electron Diffraction) beamline of KAERI (Korea Atomic Energy Research Institute) WCI (World Class Institute) Center has been successfully commissioned. A S-band co-axial RF photogun with 1.5 cylindrically symmetric cells was used to remove multiple modes of the electric filed inside the cavity. It is designed to generate sub-picosecond electron bunches with energy up to 3.3~MeV. We have developed a system consists of an in-air Faraday cup (FC) and a preamplifier for charge measurement. Tests performed utilizing 3.3~MeV electrons show the system were able to measure ultrashort bunches with tens of femtosecond pulse duration at 10 fC sensitivity. In this paper, we shall present the design, calibration and test results of this system.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB054
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MOPMB057	Automatic Microbeam Focusing for X-Ray Microbeam Experiments at the 4B Beamline of Pohang Light Source-II	focusing, controls, operation, LabView	220
	K.H. Gil, H. J. Choi, J.-H. Lim PAL, Pohang, Republic of Korea
	The 4B beamline of the Pohang Light Source-II performs X-ray microdiffraction and microfluorescence experiments using X-ray microbeams. When performing X-ray micro-experiments, an X-ray microbeam should first be prepared. Up to recently, the microbeams with vertical and horizontal sizes (full width at half maximum) of less than 3 μm have been achieved, by manually adjusting the translations and pitch angles of the vertically and horizontally focusing mirrors, in a Kirkpatrick'Baez (K-B) mirror system. In this research, we developed a program that automates the complex and cumbersome process of microbeam focusing, divided into half-cutting and focusing phases. The developed program was applied to the 4B beamline and enabled the focusing of an X-ray beam to a minimum size within one hour. This paper introduces the algorithms of the program and also examines its performance.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB057
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MOPMR003	Electron Bunch Length Measurement Using Coherent Radiation Source of fs-THz accelerator at Pohang Accelerator Laboratory	radiation, electron, linac, target	235
	J.H. Ko, I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea S.H. Jung, H.-S. Kang, I.S. Ko, J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	A Michelson interferometer was installed at the femtosecond (fs) terahertz (THz) Accelerator of Pohang Accelerator Laboratory(PAL) to measure a subpicosecond order electron bunch length. To measure an ultra-short electron bunch length, we use reconstruction process and fast fourier transform. Currently, we are generating THz radiation with the pulse energy of 7μJ by means of coherent transition radiation (CTR) from a 65-MeV electron beam of the fs-THz accelerator. In this paper, we show the how to make a longitudinal distribution of electron bunch and the radiation intensity difference between CTR and Coherent edge radiation (CER) for nondestructive electron bunch length measurement. And we report the measurement methods to get the fine electron bunch length information.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR003
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MOPMR010	The Development of Scintillating Screen Detector for Beam Monitoring at the KHIMA Project	proton, ion, cyclotron, heavy-ion	244
	S.Y. Noh, S.D. Chang, J.G. Hwang KIRAMS/KHIMA, Seoul, Republic of Korea G. Hahn, T.K. Yang KIRAMS, Seoul, Republic of Korea
	Funding: NRF-2014M2C3A1029534 It is important to measure the beam propeties such as position, size and intensity, when we control the medical beam qualities, So we developed the scintillation screen monitor used for beam profile monitoring and it will be installed at High Energy Beam Transport(HEBT) section to measure the beam parameters. This system consists of a terbium-doped gadolinium oxysulfide(Gd2O2S:Tb) phosphor screen and high speed charge coupled device camera. The CCD camera has the maximum 90 frame rate and 659 X 494 pixel resolution. This Camera is mounted at distance of 260mm from the center of the scintillation screen and with the angle of 45 degree to the scintillation screen which is mounted at the angle of 45 degree to the beam axis. The image analysis program was written in National Instruments LabVIEW using IMAQ driver. To reduce the image processing time, we optimized the prcessing flow and used LabVIEW built-in function. To evaluate this system, we measured the beam size and center position of the beam at KIRAMS on 50MeV cyclotron. In this paper, we present the manufacture of beam profile system based on a scintillating screen monitor and the in-beam test results of it.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR010
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MOPMR023	Surface Characterization and Field Emission Measurements of Copper Samples inside a Scanning Electron Microscope	electron, controls, vacuum, radio-frequency	283
	J. Ögren, V.G. Ziemann Uppsala University, Uppsala, Sweden S.H.M. Jafri, K. Leifer Uppsala University, Department of Engineering Sciences, Uppsala, Sweden
	Vacuum breakdown in normal-conducting accelerating structures is a limiting factor for high gradient acceleration. Many aspects of the physics governing the breakdown process and its onset are yet to be fully understood. At Uppsala University we address these questions with an in-situ experimental setup mounted in an environmental scanning electron microscope. It consists of a piezo motor driven tungsten needle and a sample surface mounted on a piezo stage, allowing for nano-meter 3D-position control. One of the piezo motors controls the needle-sample gap while the two other scan across the surface. A DC-voltage up to 1 kV is applied across the gap and field emission currents from a copper surface are measured with an electrometer. Here we present the setup and some initial results.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR023
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MOPMR025	Beam Size Estimation from Luminosity Scans at the LHC During 2015 Proton Physics Operation	luminosity, emittance, proton, operation	290
	M. Hostettler, G. Papotti CERN, Geneva, Switzerland M. Hostettler LHEP, Bern, Switzerland
	As a complementary method for measuring the beam size for high-intensity beams at 6.5 TeV flat-top energy, beam separation scans were done regularly at the CERN Large Hadron Collider (LHC) during 2015 proton physics operation. The luminosities measured by the CMS experiment during the scans were used to derive the convoluted beam size and orbit offset bunch-by-bunch. This contribution will elaborate on the method used to derive plane-by-plane, bunch-by-bunch emittances from the scan data, including uncertainties and corrections. The measurements are then compared to beam size estimations from absolute luminosity, synchrotron light telescopes, and wire scanners. In particular, the evolution of the emittance over the course of several hours in collisions is studied and bunch-by-bunch differences are highlighted.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR025
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MOPMR041	Experimental and Theoretical Studies of the Properties of Coherent Smith-Purcell Radiation	radiation, polarization, background, electron	344
	F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, A. Reichold JAI, Oxford, United Kingdom J. Barros, N. Delerue LAL, Orsay, France R. Bartolini DLS, Oxfordshire, United Kingdom C.I. Clarke SLAC, Menlo Park, California, USA
	Funding: This work was supported (in parts) by the UK Science and Technology Facilities Council (STFC UK) through grant ST/M003590/1 and The Leverhulme Trust through the International Network Grant IN-2015-012 Previous studies have demonstrated that coherent Smith-Purcell radiation (cSPr) can be used for relativistic electron bunch time profile reconstruction at pico-second and femtosecond scales. The E203 experiments undertaken in May 2015 at FACET (SLAC) were dedicated to the study of some properties of cSPr, namely the azimuthal distribution and the polarization of the radiation. The experimental set up description which allowed such studies will be presented along with the results. To understand the experimental data both semi-analytical and numerical models were studied. The semi-analytical approach was based on the surface-current model, and the 3D particle-in-cell code VSim was used for numerical modeling. The experimental and theoretical studies are compared.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR041
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MOPMW028	Progress on the MICE RF Module at LBNL	cavity, vacuum, operation, coupling	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
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MOPMW030	High Powered Tests of Dielectric Loaded High Pressure RF Cavities for Use in Muon Cooling Channels	accelerating-gradient, cavity, radio-frequency, plasma	460
	B.T. Freemire IIT, Chicago, Illinois, USA D.L. Bowring, A. Moretti, D.W. Peterson, A.V. Tollestrup, Y. Torun, K. Yonehara Fermilab, Batavia, Illinois, USA A.V. Kochemirovskiy University of Chicago, Chicago, Illinois, USA Y. Torun Illinois Institute of Technology, Chicago, Illlinois, USA
	Funding: This work is supported by the Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359. Bright muon sources require six dimensional cooling to achieve acceptable luminosities. Ionization cooling is the only known method able to do so within the muon lifetime. One proposed cooling channel, the Helical Cooling Channel, utilizes gas filled radio frequency cavities to both mitigate RF breakdown in the presence of strong, external magnetic fields, and provide the cooling medium. Engineering constraints on the diameter of the magnets within which these cavities operate dictate the radius of the cavities be decreased at their nominal operating frequency. To accomplish this, one may load the cavities with a larger dielectric material. Alumina of purities ranging from 96 to 99.8% was tested in a high pressure RF test cell at the MuCool Test Area at Fermilab. The results of breakdown studies with pure nitrogen gas, and oxygen-doped nitrogen gas indicate the peak surface electric field on the alumina ranges between 10 and 15 MV/m. How these results affect the design of a prototype cooling channel cavity will be discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW030
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MOPMW033	Acoustic Localization of RF Cavity Breakdown: Status and Progress	cavity, collider, simulation, status	470
	P.G. Lane, P. Snopok, Y. Torun Illinois Institute of Technology, Chicago, Illinois, USA A.V. Kochemirovskiy University of Chicago, Chicago, Illinois, USA
	Current designs for muon accelerators require high-gradient RF cavities to be placed in solenoidal magnetic fields. These fields help contain and efficiently reduce the phase space volume of source muons in order to create a usable muon beam for collider and neutrino experiments. It has been found that placing normal conducting RF cavities in strong magnetic fields reduces the threshold at which RF cavity breakdown occurs. To aid the effort to study RF cavity breakdown in magnetic fields, it would be helpful to have a diagnostic tool which can localize the source of breakdown sparks inside the cavity. These sparks generate thermal shocks to a small region of the inner cavity wall that can be detected and localized using microphones attached to the outer cavity surface. Presented here are the algorithms for and results from localizing simulated and experimental acoustic data from the Modular Cavity at the MuCool Test Area at Fermilab.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW033
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MOPMW038	Measurements of Copper RF Surface Resistance at Cryogenic Temperatures for Applications to X-Band and S-Band Accelerators	cavity, cryogenics, electron, coupling	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
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MOPMW040	Electron Beam Excitation of a Surface Wave in mm-Wave Open Accelerating Structures	electron, detector, vacuum, simulation	494
	M. Dal Forno, G.B. Bowden, C.I. Clarke, V.A. Dolgashev, M.J. Hogan, D.J. McCormick, A. Novokhatski, B.D. O'Shea, S.G. Tantawi, S.P. Weathersby SLAC, Menlo Park, California, USA B. Spataro INFN/LNF, Frascati (Roma), Italy
	Funding: Work supported by the US DOE under contract DE-AC02-76SF00515. As part of research on the physics of rf breakdowns we performed experiments with high gradient traveling-wave mm-wave accelerating structures. The accelerating structures are open, composed of two identical halves separated by an adjustable gap. The electromagnetic fields are excited by an ultra-relativistic electron beam. We observed that a confined travelling-wave mode exists in half of the accelerating structure. The experiments were conducted at FACET facility at SLAC National Accelerator Laboratory. Depending on the gap width, the accelerating structure had beam-synchronous frequencies that vary from 90 to 140 GHz. When we opened the gap by more than half wavelength the synchronous wave remains trapped. Its behavior is consistent with the so called "surface wave". We characterized this beam-wave interaction by several methods: measurement of the radiated rf energy with the pyro-detector, measurement of the spectrum with an interferometer, measurement of the beam deflection by using the beam position monitors and profile monitor.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW040
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MOPMW041	Measurements of RF Breakdowns in Beam Driven mm-Wave Accelerating Structures	vacuum, electron, detector, collider	497
	M. Dal Forno, G.B. Bowden, C.I. Clarke, V.A. Dolgashev, M.J. Hogan, D.J. McCormick, A. Novokhatski, S.G. Tantawi, S.P. Weathersby SLAC, Menlo Park, California, USA B. Spataro INFN/LNF, Frascati (Roma), Italy
	Funding: Work supported by the US DOE under contract DE-AC02-76SF00515 We studied the physics and properties of rf breakdowns in high gradient traveling-wave accelerating structures at 100 GHz. The structures are open, made of two halves with a gap in between. The rf fields were excited in the structure by an ultra-relativistic electron beam generated by the FACET facility at the SLAC National Accelerator Laboratory. We observed rf breakdowns generated in the presence of GV/m scale electric fields. We varied the rf fields excited by the FACET bunch by moving structure relative to the beam and by changing the gap between structure halves. Reliable breakdowns detectors allowed us to measure the rf breakdown rate at these different rf parameters. We measured radiated rf energy with a pyro-detector. When the beam was off-axis, we observed beam deflection in the beam position monitors and on the screen of a magnetic spectrometer. The measurements of the deflection allowed us to verify our calculation of the accelerating gradient.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW041
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MOPMW044	Design of an RF Device to Study the Multipactor Phenomenon	cavity, simulation, electron, multipactoring	507
	D. Amorim Grenoble-INP Phelma, Grenoble, France J.-M. De Conto, Y. Gómez Martínez LPSC, Grenoble Cedex, France
	Multipacting is a parasitic electron avalanche process that may occur in RF devices such as cavities or couplers. As it can be detrimental to the operation of these devices, the accelerator group at LPSC is currently designing a coaxial resonant cavity in order to study this phenomenon. In order to determine the measurable parameters on the cavity, calculations were performed and validated with numerical simulations. In a second time multipacting simulations were conducted to determine if the experiment will allow to observe multipacting.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW044
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MOPMY016	Quadrature Directional Coupling Method for Precise RF Power Measurement	coupling, radio-frequency, feedback, controls	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
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MOPOR037	Beam Halo Measurements using Vibrating Wire at the KOMAC	proton, target, laser, neutron	680
	D. Choe, M. Chung, S.Y. Kim UNIST, Ulsan, Republic of Korea S.G. Arutunian, A.V. Margaryan ANSL, Yerevan, Armenia E.G. Lazareva YSU, Yerevan, Armenia
	In high-intensity particle accelerators, due to the fact that preventing beam loss plays a crucial role in con-ducting any experiments, it is important to measure and control the beam halo. Fortunately, it is feasible nowadays to measure the beam halo region thanks to the development of several sensitive beam scanning methods, including the vibrating wire technique. Since the vibrating wire is exceptionally sensitive to the heat deposition by the beam particles, it can be used to scanning the beam profile. This study will be concentrated on the precise beam profile measurement using the vibrating wire at the Korea Multi-Purpose Accelerator Complex (KOMAC) facility. First, we describe the best condition to construct beam profile measurement experiment. Finally, we present the results of the beam halo measurements performed with 20 MeV proton beam at the KOMAC facility
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR037
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MOPOR043	High-gradient Structures for Proton Energy Boosters	booster, linac, proton, cavity	692
	S.S. Kurennoy, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV can improve radiography resolution ~10 times. The best current practice to achieve this energy boost is to employ superconducting (SC) RF cavities with gradients about 15 MV/m after the existing linac, which results in a long and expensive booster. We propose accomplishing the same with a room-sized booster based on high-gradient (100s MV/m) room-temperature RF accelerating structures operating at low duty factors. Such high-gradient (HG) structures at very high RF frequencies have been demonstrated for electrons. However, they have never been used for protons because typical RF wavelengths are smaller than the proton bunch length. This is not a problem for proton radiography (pRad): a train of very short proton bunches with the same total length (10s ps) and charge as the original proton bunch will work as well, i.e., will create one radiography frame. Such a compact HG pRad booster can also be about an order of magnitude cheaper than the SC one. We explore feasibility of HG structures for protons and their application for a compact pRad booster at LANSCE.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR043
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MOPOW049	Implementation of a Corrugated-Plate Dechirping System for GeV Electron Beam at LCLS	FEL, electron, controls, laser	824
	M.A. Harrison, P. Frigola, J.D. McNevin, A.Y. Murokh, M. Ruelas RadiaBeam Systems, Santa Monica, California, USA A.M. Babbitt, M. Carrasco, A. Cedillos, R.H. Iverson, P. Krejcik, T.J. Maxwell, '. Oven SLAC, Menlo Park, California, USA
	Funding: This work is supported by US DOE Grant No. DE-SC0009550. A new corrugated-plate Dechirper was recently installed in the LCLS and underwent commissioning tests to gauge its efficacy in shaping the longitudinal phase space of bunches entering the FEL. Here, we describe in detail the completed four-meter LCLS Dechirper system along with a narrative of its construction. We detail the various challenges and lessons learned in the manufacturing and assembly of this first-of-its-kind device. An outlook on future designs is presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW049
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MOPOY009	ELENA: Installations and Preparations for Commissioning	antiproton, electron, emittance, extraction	860
	C. Carli, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, T. Eriksson, R. Ostojić, S. Pasinelli, G. Tranquille CERN, Geneva, Switzerland W. Oelert Johannes Gutenberg University Mainz, Institut für Physik, Mainz, Germany
	The Extra Low Energy Antiproton ring (ELENA) is a small 30 m circumference synchroton under construction at CERN to further decelerate antiprotons from the Antiproton Decelerator AD from 5.3 MeV to 100 keV. Controlled deceleration in a synchrotron equipped with an electron cooler to reduce emittances in all three planes will allow the existing AD experiments to increase substantially their antiproton capture efficiencies and render new experiments possible. Installation of the machine and lines needed for the commissioning of the ring are ongoing and commissioning is expected to start around mid-2016. The aim is to complete ELENA ring commissioning in November followed by the installation of new electrostatic transfer lines to existing experiments until autumn 2017. Status of ELENA installations and preparations for commissioning will be reported.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY009
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MOPOY012	Space Charge Simulations in the Fermilab Recycler for PIP-II	simulation, space-charge, proton, booster	870
	R. Ainsworth, P. Adamson, I. Kourbanis, E.G. Stern Fermilab, Batavia, Illinois, USA
	Proton Improvement Plan-II (PIP-II) is Fermilab's plan for providing powerful, high-intensity proton beams to the laboratory's experiments. Upgrades are foreseen for the recycler which will cope with bunches containing fifty percent more beam. Of particular concern is large space charge tune shifts caused by the intensity increase. Simulations performed using Synergia are detailed focusing on the space charge footprint.
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MOPOY032	Beam Twiss Measurement With Ws Including Space Charge Effect	space-charge, lattice, simulation, rfq	925
	Y.L. Zhao, H. Geng, C. Meng, F. Yan IHEP, Beijing, People's Republic of China
	Wire Scanners (WS) are used to measure beam profile and calculate the transverse Twiss parameters at the entrance of MEBT1 in the CADS injector I test stand. As to data process, the traditional method with transfer map doesn't consider the space charge effect. But, as we know, space charge effect can't be neglected for high intensity accelerators. In this paper, optimization algorithm is used in beam emittance measurement.
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MOPOY060	Performance Analysis for the New g-2 Experiment at Fermilab	simulation, storage-ring, injection, dipole	996
	D. Stratakis, M.E. Convery, C. Johnstone, J.A. Johnstone, J.P. Morgan, M.J. Syphers Fermilab, Batavia, Illinois, USA J.D. Crmkovic, W. Morse, V. Tishchenko BNL, Upton, Long Island, New York, USA N.S. Froemming University of Washington, CENPA, Seattle, USA M. Korostelev Cockcroft Institute, Warrington, Cheshire, United Kingdom M. Korostelev Lancaster University, Lancaster, United Kingdom
	The new g-2 experiment at Fermilab aims to measure the muon anomalous magnetic moment to a precision of ±0.14 ppm ─ a fourfold improvement over the 0.54 ppm precision obtained in the g-2 BNL E821experiment. Achieving this goal requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we describe a muon capture and transport scheme that should meet this requirement. First, we present the conceptual design of our proposed scheme wherein we describe its basic features. Then, we detail its performance numerically by simulating the pion production in the (g-2) production target, the muon collection by the downstream beamline optics as well as the beam polarization and spin-momentum correlation up to the storage ring. The sensitivity in performance of our proposed channel against key parameters such as magnet apertures and magnet positioning errors is analyzed
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TUOAA03	Long Term Plans to Increase Fermilab's Proton Intensity to Meet the Needs of the Long Baseline Neutrino Program	proton, linac, booster, injection	1010
	E. Prebys, P. Adamson, S.C. Childress, P. Derwent, S.D. Holmes, I. Kourbanis, V.A. Lebedev, W. Pellico, A. Romanenko, V.D. Shiltsev, E.G. Stern, A. Valishev, R.M. Zwaska Fermilab, Batavia, Illinois, USA
	Funding: This work is supported by the US Department of Energy under contract No. De-AC02-07CH11359. The flagship of Fermilab's long term research program is the Deep Underground Neutrino Experiment (DUNE), located Sanford Underground Research Facility (SURF) in Lead, South Dakota, which will study neutrino oscillations with a baseline of 1300 km. The neutrinos will be produced in the Long Baseline Neutrino Facility (LBNF), a proposed new beam line from Fermilab's Main Injector. The physics goals of the DUNE require a proton beam with a power of roughly 2.5 MW at 120 GeV, which is roughly five times the current maximum power. This poster outlines the staged plan to achieve the required power over the next 15 years.
	Slides TUOAA03 [4.129 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOAA03
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TUOBA02	ER@CEBAF - A High Energy, Multi-pass Energy Recovery Experiment at CEBAF	linac, operation, optics, electron	1022
	F. Méot, I. Ben-Zvi, Y. Hao, P. Korysko, C. Liu, M.G. Minty, V. Ptitsyn, G. Robert-Demolaize, T. Roser, P. Thieberger, N. Tsoupas BNL, Upton, Long Island, New York, USA M.E. Bevins, S.A. Bogacz, D. Douglas, C.J. Dubbe, T.J. Michalski, F.C. Pilat, Y. Roblin, T. Satogata, M. Spata, C. Tennant, M.G. Tiefenback JLab, Newport News, Virginia, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A high-energy, multiple-pass energy recovery (ER) experiment proposal, using CEBAF, is in preparation by a JLab-BNL collaboration. The experiment will be proposed in support of the electron-ion collider project (EIC) R&D going on at BNL. This new experiment extends the 2003, 1-pass, 1 GeV CEBAF-ER demonstration into a range of energy and recirculation passes commensurate with BNL's anticipated linac-ring EIC parameters. The experiment will study ER and recirculating beam dynamics in the presence of synchrotron radiation, provide opportunity to develop and test multiple-beam diagnostic instrumentation, and can also probe BBU limitations. This paper gives an overview of the ER@CEBAF project, its context and preparations.
	Slides TUOBA02 [1.936 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOBA02
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TUOBB01	Demonstration of Current Profile Shaping using Double Dog-Leg Emittance Exchange Beam Line at Argonne Wakefield Accelerator	emittance, quadrupole, dipole, wakefield	1065
	G. Ha, M.-H. Cho, W. Namkung POSTECH, Pohang, Kyungbuk, Republic of Korea M.E. Conde, D.S. Doran, W. Gai, G. Ha, K.-J. Kim, W. Liu, J.G. Power, Y.-E. Sun, C. Whiteford, E.E. Wisniewski, A. Zholents ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA P. Piot Fermilab, Batavia, Illinois, USA
	Emittance exchange (EEX) based longitudinal current profile shaping is the one of the promising current profile shaping technique. This method can generate high quality arbitrary current profiles under the ideal conditions. The double dog-leg EEX beam line was recently installed at the Argonne Wakefield Accelerator (AWA) to explore the shaping capability and confirm the quality of this method. To demonstrate the arbitrary current profile generation, several different transverse masks are applied to generate different final current profiles. The phase space slopes and the charge of incoming beam are varied to observe and suppress the aberrations on the ideal profile. We present current profile shaping results, aberrations on the shaped profile, and its suppression.
	Slides TUOBB01 [5.032 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOBB01
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TUPMB008	Beam-Based Alignment for the Transport Line of CSNS	alignment, controls, DTL, linac	1121
	Y. Li, Y.W. An, Z.P. Li, W.B. Liu, S. Wang IHEP, Beijing, People's Republic of China
	Beam-based alignment (BBA) techniques are important tools for beam orbit steering in linear accelerators or transfer lines. In this paper this technique and the control system application programs developed based on XAL platform were applied to the beam commissioning for Medium Energy Beam Transport (MEBT) of CSNS to get the transverse misalignments of beam position monitor (BPM) and quad. The results shows that the absolute values of BPMs offsets are less than 0.6 mm and quads offsets are less than 0.05 mm，that is much smaller than the tolerance of the misalignment.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB008
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TUPMB009	Vibrating Wire Measurements for the XiPAF Permanent Magnet Quadrupoles	multipole, background, permanent-magnet, DTL	1124
	B.C. Wang, 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 C.T. Du, X.W. Wang, L. Wu, Q.Z. Xing, S.X. Zheng TUB, Beijing, People's Republic of China
	Vibrating wire technique is a promising measure-ment method for small-aperture Permanent Magnet Quadrupoles (PMQs) in linear accelerators and scan-ning nuclear microprobes. In this paper, we describe the improved vibrating wire setup for measuring an individual PMQ with the minimum aperture of several millimeters. This setup is aiming at measuring the magnetic center. The advantage of this setup is that any mechanical measurement on the wire, which may be the main error source, is avoided. Experiments of the 20 mm-aperture Halbach-type PMQs for Xi'an Proton Application Facility (XiPAF) DTL has been carried out. The research results of the magnetic center measurements show a precision of about 10 μm and robustness against the background magnetic field. Results of the magnetic center and field multipoles measurements agree with the ones obtained from the rotating coil.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB009
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TUPMB010	Magnetic Center Position and Tilt Angle of Quadrupole by Vibration Wire Method	quadrupole, radiation, alignment, superconductivity	1127
	L. Wu, X. Guan, X.W. Wang, S.X. Zheng TUB, Beijing, People's Republic of China B.C. Wang NINT, Xi'an, People's Republic of China G. Xialing CIAE, Beijing, People's Republic of China
	Vibrating wire method and device are described to locate the magnetic center of a Quadrupole theoretically and experimentally. With rotating 180 degrees method, it is convenience to measure the position magnetic center from mechanical center. Tilt angle can also be measured because tilt of magnetic axis will cause the difference of measured magnetic center in different harmonic driving current frequency. Errors analysis shows that tilt of Quadrupole will cause the main error and improved device is described to adjust and measure the tilt angle to fix the errors caused by tilt.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB010
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TUPMB049	Development of Separator Cooling System for Helium	cryogenics, radiation, controls, vacuum	1209
	W.R. Liao, S.-H. Chang, W.-S. Chiou, P.S.D. Chuang, F. Z. Hsiao, H.C. Li, T.F. Lin, H.H. Tsai NSRRC, Hsinchu, Taiwan
	A helium phase separator with a condenser is under fabrication and assembled at National Synchrotron Radiation Research Centre (NSRRC). The objective of a helium phase separator with its condenser is to separate two-phase helium flow and to re-condense vaporized gaseous helium with a cryocooler of Gifford-McMahon type. We developed a 100 litre (ltr) helium phase separator with a small heat loss as a prototype. The experimental results for the total cooling capacity of the phase separator are 0.73 W at 1.67 bara, which includes the effect of thermal conduction and thermal radiation from the environment. The helium liquefaction rate is 2 ltr/day with a 100 ltr vessel. The mechanism of heat transfer in phase separator was investigated and discussed. This paper presents the experiment of helium liquefaction process of 100 ltr separator with condenser, which was a key component of the helium phase separator.
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TUPMB052	High Intensity Beam Test of Low Z Materials for the Upgrade of SPS-to-LHC Transfer Line Collimators and LHC Injection Absorbers	simulation, injection, proton, radiation	1218
	F.L. Maciariello, O. Aberle, M.E.J. Butcher, M. Calviani, R. Folch, V. Kain, K. Karagiannis, I. Lamas Garcia, A. Lechner, F.-X. Nuiry, G.E. Steele, J.A. Uythoven CERN, Geneva, Switzerland
	In the framework of the LHC Injector Upgrade (LIU) and High-Luminosity LHC (HL-LHC) project, the collimators in the SPS-to LHC transfer lines will undergo important modifications. The changes to these collimators will allow them to cope with beam brightness and intensity levels much increased with respect to their original design parameters: nominal and ultimate LHC. The necessity for replacement of the current materials will need to be confirmed by a test in the High Radiation to Materials (HRM) facility at CERN. This test will involve low Z materials (such as Graphite and 3-D Carbon/Carbon composite), and will recreate the worst case scenario those materials could see when directly impacted by High luminosity LHC (HL-LHC) or Batch Compression Merging and Splitting (BCMS) beams. Thermo-structural simulations used for the material studies and research, the experiment preparation phase, the experiment itself, pre irradiation analysis (including ultrasound and metrology tests on the target materials), the results and their correlation with numerical simulations will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB052
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TUPMR004	Simulations of High Current NuMI Magnetic Horn Striplines at FNAL	simulation, proton, target, focusing	1230
	T. Sipahi, S. Biedron, S.V. Milton CSU, Fort Collins, Colorado, USA J. Hylen, R.M. Zwaska Fermilab, Batavia, Illinois, USA
	Both the NuMI (Neutrinos and the Main Injector) beam line, that has been providing intense neutrino beams for several Fermilab experiments (MINOS, MINERVA, NOVA), and the newly proposed LBNF (Long Baseline Neutrino Facility) beam line which plans to produce the highest power neutrino beam in the world for DUNE (the Deep Underground Neutrino Experiment) need pulsed magnetic horns to focus the mesons which decay to produce the neutrinos. The high-current horn and stripline design has been evolving as NuMI reconfigures for higher beam power and to meet the needs of the LBNF design. The CSU particle accelerator group has aided the neutrino physics experiments at Fermilab by producing EM simulations of magnetic horns and the required high-current striplines. In this paper, we present calculations, using the Poisson and ANSYS Maxwell 3D codes, of the EM interaction of the stripline plates of the NuMI horns at critical stress points. In addition, we give the electrical simulation results using the ANSYS Electric code. These results are being used to support the development of evolving horn stripline designs to handle increased electrical current and higher beam power for NuMI upgrades and for LBNF
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR004
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TUPMR005	First Results of a Turbo Generator Test for Powering the HV-Solenoids at a Relativistic Electron Cooler	electron, solenoid, high-voltage, power-supply	1233
	A. Hofmann, K. Aulenbacher, M.W. Bruker, J. Dietrich, T. Weilbach HIM, Mainz, Germany W. Klag IKP, Mainz, Germany V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk, Russia
	One of the challenges in a relativistic electron cooler is the generation of high voltage exceeding 2 MV and the powering of HV-solenoids, which need a floating power supply. As replacement of the well established, but limited, methods we propose streaming gas for the power transfer. The conversion of the energy by a turbo generator enables using scalable power supply / HV-generator combinations. BINP SB RAS has proposed two possibilities to build the power supply in a modular way. In the first proposal, two cascade transformers per module should be used; the first one powers 22 small HV-solenoids, the second one generates the voltage. In order to reach the final voltage, the modules are cascaded. The cascade transformers are fed by a turbo generator, which is driven by pressurised gas. The second possibility is to use two big HV-solenoids, which are powered directly by a turbo generator. The voltage could be generated for example with a Cockcroft Walton generator. A potential candidate is the Green Energy Turbine (GET) from the company DEPRAG, Germany. At the Helmholtz-Institut Mainz, two GET were tested. In this report, we present our experience and show first results.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR005
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TUPMR023	First Operational Experience of HIE-Isolde	detector, dipole, ion, target	1284
	J.A. Rodriguez, N. Bidault, E. Bravin, R. Catherall, E. Fadakis, P. Fernier, M.A. Fraser, M.J. Garcia Borge, K. Hanke, K. Johnston, Y. Kadi, M. Kowalska, M.L. Lozano Benito, E. Matli, S. Sadovich, E. Siesling, W. Venturini Delsolaro, F.J.C. Wenander CERN, Geneva, Switzerland M. Huyse, P. Van Duppen KU Leuven, Leuven, Belgium J. Pakarinen JYFL, Jyväskylä, Finland E. Rapisarda PSI, Villigen PSI, Switzerland M. Zielinska Warsaw University, Warsaw, Poland
	The High Intensity and Energy ISOLDE project (HIE-ISOLDE)* is a major upgrade of the ISOLDE facility at CERN. The energy range of the post-accelerator will be extended from 2.85 MeV/u to 9.3 MeV/u for beams with A/q = 4.5 (and to 14.3 MeV/u for A/q = 2.5) once all the cryomodules of the superconducting accelerator are in place. The project has been divided into different phases, the first of which (phase 1a) finished in October 2015 after the hardware and beam commissioning were completed*. The physics campaign followed with the delivery of both radioactive and stable beams to two different experimental stations. The characteristics of the beams (energies, intensities, time structure and beam contaminants) and the plans for the next experimental campaign will be discussed in this paper. The HIE-ISOLDE Project, Journal of Physics: Conference Series 312. HIE-ISOLDE First Commissioning Experience, IPAC'16 Beam Commissioning of the HIE-ISOLDE Post-Accelerator, IPAC'16
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR023
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TUPMR024	Commissioning and First Accelerated Beams in the Reaccelerator (Rea3) of the National Superconducting Cyclotron Laboratory, MSU	ion, rfq, acceleration, cyclotron	1287
	A.C.C. Villari, G. Bollen, M. Ikegami, S.M. Lidia, R. Shane, Q. Zhao FRIB, East Lansing, Michigan, USA D.M. Alt, D.B. Crisp, S.W. Krause, A. Lapierre, D.J. Morrissey, S. Nash, R. Rencsok, R.J. Ringle, S. Schwarz, C. Sumithrarachchi, S.J. Williams NSCL, East Lansing, Michigan, USA
	The ReAccelerator ReA3 is a worldwide unique, state-of-the-art reaccelerator for rare isotope beams. Beams of rare isotopes are produced and separated in-flight at the NSCL Coupled Cyclotron Facility and subsequently stopped in a gas cell. The rare isotopes are then continuously extracted as 1+ (or 2+) ions and transported into a beam cooler and buncher, followed by a charge breeder based on an Electron Beam Ion Trap (EBIT). In the charge breeder, the ions are ionized to a charge state suitable for acceleration in the superconducting radiofrequency (SRF) linac, extracted in a pulsed mode and mass analyzed. The extracted beam is bunched to 80.5 MHz and then accelerated to energies ranging from 300 keV/u up to 6 MeV/u, depending on their charge-to-mass ratio. Alternatively, stable isotope ions can be accelerated injecting stable gas in the EBIT. ReA3 was commissioned recently with stable 40Ar and 39K as well as with the rare isotope beams of 46Ar and 46K. This contribution will focus on the properties and techniques used to accelerate and transport rare isotope beams and will show results obtained during the preparation of the two first experiments using the ReA facility.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR024
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TUPMR027	CERN's Fixed Target Primary Ion Programme	ion, extraction, target, proton	1297
	D. Manglunki, M.E. Angoletta, J. Axensalva, G. Bellodi, A. Blas, M.A. Bodendorfer, T. Bohl, S. Cettour-Cave, K. Cornelis, H. Damerau, I. Efthymiopoulos, A. Fabich, J.A. Ferreira Somoza, A. Findlay, P. Freyermuth, S.S. Gilardoni, S. Hancock, E.B. Holzer, S. Jensen, V. Kain, D. Küchler, A.M. Lombardi, A.I. Michet, M. O'Neil, S. Pasinelli, R. Scrivens, R. Steerenberg, G. Tranquille CERN, Geneva, Switzerland
	The renewed availability of heavy ions at CERN for the needs of the LHC programme has triggered the interest of the fixed-target community. The project, which involves sending several species of primary ions at various energies to the North Area of the Super Proton Synchrotron, has now entered its operational phase. The first argon run, with momenta ranging from 13 AGeV/c to 150 AGeV/c, took place from February 2015 to April 2015. This paper presents the status of the project, the performance achieved thus far and an outlook on future plans.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR027
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TUPMR028	Spin Correlations Study for the New g-2 Experiment at Fermilab	storage-ring, simulation, injection, quadrupole	1301
	D. Stratakis, J.D. Crnkovic, W. Morse, V. Tishchenko BNL, Upton, Long Island, New York, USA
	The muon g-2 experiment executed at Brookhaven concluded in 2001 and measured a discrepancy of more than three standard deviations compared to the Standard Model (SM) calculation. A new initiative at Fermilab is under construction to improve the experimental accuracy four-fold. Achieving this goal, however, requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we examine systematic errors that can arise from correlations between muon spin and transverse coordinates for the new g-2 experiment. To achieve this goal we perform end-to-end spin tracking simulations from the production target up to the ring injection point and compare our findings against the results from the Brookhaven experiment. We detail similarities and differences.
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TUPMR042	Transverse Profile Expansion and Homogenization for the Beamline of XIPAF	target, proton, optics, simulation	1346
	Z. Yang, C.T. Du, X. Guan, W. Wang, X.W. Wang, H.J. Yao, S.X. Zheng TUB, Beijing, People's Republic of China
	For the Xi'an 200 MeV Proton Application Facility (XiPAF), one important thing is to produce more homog-enous beam profile at the target to fulfill the requirements of the beam application. Here the beam line is designed to meet the requirement of beam expansion and homogenization, and the step-like field magnets are employed for the beam spot homogenization. The simulations results including space charge effects and errors show that the beam line can meet the requirements well at the different energies (from 10 MeV to 230 MeV) and different beam spot size (from 20mm to 200mm).
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR042
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TUPMR052	Commissioning Preparation of the AWAKE Proton Beam Line	proton, laser, plasma, extraction	1374
	J.S. Schmidt, B. Biskup, C. Bracco, B. Goddard, R. Gorbonosov, M. Gourber-Pace, E. Gschwendtner, L.K. Jensen, O.R. Jones, V. Kain, S. Mazzoni, M. Meddahi CERN, Geneva, Switzerland
	The AWAKE experiment at CERN will use a proton bunch with an momentum of 400 GeV/c from the SPS to drive large amplitude wakefields in a plasma. This will require a ~830 m long transfer line from the SPS to the experiment. The prepa- rations for the beam commissioning of the AWAKE proton transfer line are presented in this paper. They include the detailed planning of the commissioning steps, controls and beam instrumentation specifications as well as operational tools, which are developed for the steering and monitoring of the beam line. The installation of the transfer line has been finished and first beam is planned in summer 2016.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR052
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TUPMW007	Impact of Long Range Beam-Beam Effects on Intensity and Luminosity Lifetimes from the 2015 LHC Run	luminosity, emittance, hadron, dynamic-aperture	1422
	M.P. Crouch, R.B. Appleby UMAN, Manchester, United Kingdom D. Banfi, C. Tambasco EPFL, Lausanne, Switzerland J. Barranco, R. Bruce, X. Buffat, T. Pieloni, M. Pojer, B. Salvachua, G. Trad CERN, Geneva, Switzerland B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Research supported by the High Luminosity LHC project Luminosity is one of the key parameters that determines the performance of colliding beams in the Large Hadron Collider (LHC). Luminosity can therefore be used to quantify the impact of beam-beam interactions on the beam lifetimes and emittances. The High Luminosity Large Hadron Collider (HL-LHC) project aims to reach higher luminosities, approximately a factor of 7 larger than the nominal LHC at peak luminosity without crab cavities. Higher luminosities are achieved by increasing the bunch populations and reducing the transverse beam sizes. This results in stronger beam-beam effects. Here the LHC luminosity and beam intensity decay rates are analysed as a function of reducing beam separation with the aim of characterising the impact of beam-beam effects on the luminosity and beam lifetime. The analysis and results are discussed with possible application to the HL-LHC upgrade.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW007
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TUPMW012	Beam Offset Stabilization Techniques for the LHC Collision Points	luminosity, optics, ground-motion, operation	1438
	A.A. Gorzawski, R. Jacobsson, J. Wenninger CERN, Geneva, Switzerland
	Maintaining head-on collisions over many hours is an important aspect of optimizing the performance of a collider. For current LHC operation where the beam optics is fixed during periods of colliding beam, mainly ground motion induced perturbations have to be compensated. The situation will become significantly more complex when luminosity leveling will be applied following the LHC luminosity upgrades. During β^* leveling the optics in the interaction region changes significantly, feed-downs from quadrupole misalignment may induce significant orbit changes that may lead to beam offsets at the collision points. Such beam offsets induce a loss of luminosity and reduce the stability margins for collective effects that is provided by head-on beam-beam. It is therefore essential that the beam offsets at the collision points are minimized during the leveling process. This paper will review sources and mitigation techniques for the orbit perturbation at the collision points during β^* leveling, and present results of experiments performed at the LHC to mitigate and compensate such offsets.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW012
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TUPMW013	Experimental Demonstration of β* Leveling at the LHC	luminosity, betatron, controls, emittance	1442
	A.A. Gorzawski, D. Mirarchi, B. Salvachua, J. Wenninger CERN, Geneva, Switzerland
	The HL-LHC project foresees to boost the LHC peak luminosity beyond the capabilities of the LHC experimental detectors. Leveling the luminosity down to a constant value that is sustainable for the experiments is therefore the operational baseline of HL-LHC. Various luminosity leveling techniques are available at the LHC. Leveling by adjusting β^, the betatron function at the interaction point, to maintain a constant luminosity is favorable because the beams remain head-on which provides optimal stability from the point of view of collective effects. Smooth leveling by β^ requires however excellent control of the beam orbits and beam losses in the interaction regions since the beam offsets should not vary by more than around one r.m.s. beam size during the process. This leveling scheme has been successfully tested and experimentally demonstrated during the LHC machine development program in 2015. This paper presents results on luminosity leveling over a β^* range from 10 m to 0.8 m and provides an outlook on future developments and use of this technique at the LHC.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW013
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TUPMW027	The 2015 Heavy-Ion Run of the LHC	luminosity, ion, heavy-ion, operation	1493
	J.M. Jowett, R. Alemany-Fernandez, R. Bruce, M. Giovannozzi, P.D. Hermes, W. Höfle, M. Lamont, T. Mertens, S. Redaelli, M. Schaumann, J.A. Uythoven, J. Wenninger CERN, Geneva, Switzerland
	In late 2015 the LHC collided lead nuclei at a beam energy of 6.37 Z TeV, chosen to match the 5.02 TeV per colliding nucleon pair of the p-Pb collision run in 2013. In so doing, it surpassed its design luminosity by a factor of 2. Besides the higher energy, the operational configuration had a number of new features with respect to the previous Pb-Pb run at 3.5 Z TeV in 2011; unusual bunch patterns providing collisions in the LHCb experiment for the first time, luminosity levelling and sharing requirements, a vertical displacement of the interaction point in the ALICE experiment, and operation closer to magnet quench limits with mitigation measures. We present a summary of the commissioning and operation and what has been learned in view of future heavy-ion operation at higher luminosity.
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TUPMW028	Bound-Free Pair Production in LHC Pb-Pb Operation at 6.37 Z TeV per Beam	luminosity, ion, dipole, simulation	1497
	J.M. Jowett, B. Auchmann, C. Bahamonde Castro, M.K. Kalliokoski, A. Lechner, T. Mertens, M. Schaumann, C. Xu CERN, Geneva, Switzerland
	In the 2015 Pb-Pb collision run of the LHC, the power of the secondary beams emitted from the interaction point by the bound-free pair production process reached new levels while the propensity of the bending magnets to quench is higher at the new magnetic field levels. This beam power is about 70 times greater than that contained in the luminosity debris and is focussed on a specific location. As long foreseen, orbit bumps were introduced in the dispersion suppressors around the highest luminosity experiments to mitigate the risk by displacing and spreading out these losses. An experiment designed to induce quenches and determine the quench levels and luminosity limit was carried out to assess the need for special collimators to intercept these secondary beams.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW028
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TUPMY004	The MICE Demonstration of Muon Ionization Cooling	emittance, lattice, betatron, simulation	1547
	J.-B. Lagrange, C. Hunt, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom V.C. Palladino INFN-Napoli, Napoli, Italy J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	Funding: STFC, DOE, NSF, INFN, CHIPP AND MORE Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams necessary to elucidate the physics of flavour at the Neutrino Factory and to provide lepton-antilepton collisions up to several TeV at the Muon Collider. The international Muon Ionization Cooling Experiment (MICE) will demonstrate muon ionization cooling, the technique proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam traverses a material (the absorber) loosing energy, which is replaced using RF cavities. The combined effect is to reduce the transverse emittance of the beam (transverse cooling). The configuration of MICE required to deliver the demonstration of ionization cooling is being prepared in parallel to the execution of a programme designed to measure the cooling properties of liquid-hydrogen and lithium hydride. The design of the cooling-demonstration experiment will be presented together with a summary of the performance of each of its components and the cooling performance of the experiment. Submitted by the MICE speakers bureau that will identify later a member of the collaboration to present the contribution
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY004
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TUPMY008	Phase Rotation of Muon Beams for Producing Intense Low-energy Muon Beams	proton, simulation, target, solenoid	1556
	Y. Bao, Y. Bao, G. Hansen UCR, Riverside, California, USA D.V. Neuffer Fermilab, Batavia, Illinois, USA
	Low-energy muon beams are useful for rare decay researches, providing access to new physics that cannot be addressed at high-energy colliders. However, the large initial energy spread of the muon beam greatly limits the efficiency of muon applications. In this paper we outline a phase rotation method to significantly increase the intensity of low-energy muons. The muons are first produced by a short pulsed proton driver, and after a drift channel they form a time-momentum correlation. A series of rf cavities is used to bunch the muons and then phase rotate the bunches so that all the bunches reaches a momentum around 100 MeV/c. Then another group of rf cavities is used to decelerate the muon bunches to low-energy. Such a method produces low-energy muons with an efficiency of 0.1 muon per 8 GeV proton, which is significantly higher than the current Mu2e experiment at Fermilab, and it provides the possibility for the next generation rare decay researches.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY008
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TUPMY010	Status of Mice Step IV	emittance, factory, optics, scattering	1562
	P.M. Hanlet IIT, Chicago, Illinois, USA
	Funding: STFC, DOE, NSF, INFN, CHIPP AND MORE Muon beams of low emittance provide the basis for the intense, well characterised neutrino beams of the Neutrino Factory and for lepton-antilepton collisions at energies of up to several TeV at a Muon Collider. The international Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling–the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam. MICE is being constructed in a series of Steps. The configuration currently in operation at the Rutherford Appleton Laboratory is optimised for the study the properties of liquid hydrogen and lithium hydride that affect cooling. The plans for data taking in the present configuration will be described together with a summary of the status of preparation of the experimental configuration by which MICE will demonstration the principle of ionization cooling. Submitted by the MICE speakers bureau that will identify later a member of the collaboration to present the contribution
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY010
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TUPMY012	Hybrid Methods for Simulation of Muon Ionization Cooling Channels	simulation, emittance, scattering, lattice	1568
	J.D. Kunz IIT, Chicago, Illinois, USA M. Berz, K. Makino MSU, East Lansing, Michigan, USA P. Snopok Illinois Institute of Technology, Chicago, Illlinois, USA
	Funding: Work is supported by the U.S. Department of Energy. COSY Infinity is an arbitrary-order beam dynamics simulation and analysis code. It can determine high-order transfer maps of combinations of particle optical elements of arbitrary field configurations. New features are being developed for inclusion in COSY to follow the distribution of charged particles through matter. To study in detail some of the properties of muons passing through material, the transfer map approach alone is not sufficient. The interplay of beam optics and atomic processes must be studied by a hybrid transfer map–Monte Carlo approach in which transfer map methods describe the deterministic behavior of the particles in the accelerator channel, and Monte Carlo methods are used to model the stochastic processes intrinsic to liquid and solid absorbers. The advantage of the new approach is that the vast majority of the dynamics is represented by fast application of the high-order transfer map of an entire element and accumulated stochastic effects. The gains in speed are expected to simplify the optimization of muon cooling channels which are usually very computationally demanding. Progress on the development of the required algorithms is reported.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY012
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TUPMY030	Measurements of Transmitted Electron Beam Extinction through Si Crystal Membranes	electron, emittance, scattering, laser	1611
	E.A. Nanni, R.K. Li, C. Limborg, X. Shen, S.P. Weathersby SLAC, Menlo Park, California, USA W.S. Graves, R. Kirian, J. Spence, U. Weierstall Arizona State University, Tempe, USA
	A recently proposed method for the generation of relativistic electron beams with nanometer-scale current modulation requires diffracting relativistic electrons from a perfect crystal Si grating, accelerating the diffracted beam and imaging the crystal structure into the temporal dimension via emittance exchange. The relative intensity of the current modulation is limited by the ability to extinguish the transmitted beam via diffraction with a single-crystal Si membrane. In these preliminary experiments we will measure the extinction of the transmitted electron beam at zero scattering angle due to multiple Bragg scattering from a Si membrane with a uniform thickness of 340 nm at 2.35 MeV using the SLAC UED facility. The impact of beam divergence and charge density at the Si target will be quantified. The longevity of the Si membrane will also be investigated by monitoring the diffraction pattern as a function of time to observe the potential onset of damage to the crystal.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY030
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TUPMY038	Preliminary Measurement of the Transfer Matrix of a TESLA-type Cavity at FAST	cavity, simulation, HOM, focusing	1632
	A. Halavanau, P. Piot Northern Illinois University, DeKalb, Illinois, USA N. Eddy, D.R. Edstrom, A. Lunin, P. Piot, J. Ruan, J.K. Santucci, J.K. Santucci, N. Solyak Fermilab, Batavia, Illinois, USA
	Funding: US Department of Energy (DOE) under contract DE-SC0011831 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359. Superconducting linacs are capable of producing intense, ultra-stable, high-quality electron beams that have widespread application in Science and Industry. Many current and planned projects employ 1.3-GHz 9-cell superconducting cavities of the TESLA design. In the present paper we discuss the transverse-focusing properties of such a cavity and non-ideal transverse-map effects introduced by field asymmetries in the vicinity of the input and high-order-mode radiofrequency (RF) couplers. We especially consider the case of a cavity located downstream of an RF-gun in a setup similar to the photoinjector of the Fermilab Accelerator Science and Technology (FAST) facility. Preliminary experimental measurements of the CC2 cavity transverse matrix were carried out at the FAST facility. The results are discussed and compared with analytical and numerical simulations. A. Aunes et al., Phys. Rev.ST Accel. Beams 3, 092001 (2000). ** P. Piot, el. al., Proc. 2005 Part. Accel. Conf., Knoxville, TN, p. 4135 (2005).
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY038
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TUPOR025	Beam Break-up Measurements at the Recirculating Electron Accelerator S-DALINAC	linac, recirculation, HOM, cavity	1714
	T. Kürzeder, M. Arnold, L.E. Jürgensen, J. Pforr, N. Pietralla TU Darmstadt, Darmstadt, Germany F. Hug IKP, Mainz, Germany
	Funding: Supported by the German Federal Ministry for Education and Research (BMBF) under Grant No. 05K13RDA Beam break-up (BBU) instability is an important limitation to the current which can be accelerated in a superconducting linac. In particular recirculating machines and Energy Recovery Linacs have to deal with that problem. Therefore, it is important to find strategies for increasing the threshold currents of these machines. The superconducting accelerator S-DALINAC at the Technische Universität Darmstadt provides electron beams in c.w. for nuclear physics experiments since 1991. It consists of a 10 MeV injector and a 40 MeV main linac where two and eight 20-cell elliptical 3-GHz cavities are operated in a liquid helium bath at 2 K. Using two recirculation beam lines the main accelerator can be used up to 3 times. Operational experiences have shown that the design-beam current of 20 μA could not be reached. One reason is the occurrence of BBU. We will report on measurements of the threshold current at various energy settings of the S-DALINAC. The results of a first test to increase the BBU limit by using skew quadrupole magnets in the first recirculation beam line will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR025
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TUPOR031	Trapped Ion Effects and Mitigation During High Current Operation in the Cornell DC Photoinjector	ion, radiation, linac, vacuum	1735
	S.J. Full, A.C. Bartnik, I.V. Bazarov, J. Dobbins, B.M. Dunham, G.H. Hoffstaetter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: U.S. Department of Energy (Grant No. DE-SC0012493), National Science Foundation (Award No. NSF-DMR 0807731) The Cornell high intensity photoinjector reaches a new regime of linac beam parameters where high continuous-wave electron beam currents lead to ion trapping. Above 10 mA, we have observed beam trips that limit stable machine operation to approximately 10^-15 minutes. By applying known ion clearing methods, the machine lifetime increases to at least 24 hours of continuous operation, suggesting that trapped ions are the most likely cause of the trips. In this paper we share some of our observations ion trapping in the photoinjector, as well as experimental tests of three common ion mitigation methods: clearing electrodes, beam shaking and bunch gaps.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR031
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TUPOW002	Current Status of the Milliampere Booster for the Mainz Energy-recovering Superconducting Accelerator	electron, simulation, linac, gun	1741
	R.G. Heine, K. Aulenbacher, L.M. Hein, C. Matejcek IKP, Mainz, Germany
	Funding: Work supported by German Science Foundation (DFG) under the Cluster of Excellence "PRISMA" EXC1098/2014 The Milliampere Booster (MAMBO) is the injector linac for the Mainz Energy-recovering Superconducting Accelerator MESA. The MESA facility is currently under design at the Institut für Kernphysik (KPH) at Johannes Gutenberg University of Mainz (JGU). In this paper we will present the current design status of the linac.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW002
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TUPOW015	Experiment of High Resolution Field Emission Imaging in an rf Photocathode Gun	cathode, electron, gun, background	1772
	J.H. Shao, H.B. Chen, J. Shi, X.W. Wu TUB, Beijing, People's Republic of China S.P. Antipov, S.V. Baryshev, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA M.E. Conde, W. Gai, G. Ha, E.E. Wisniewski ANL, Argonne, Illinois, USA F.Y. Wang SLAC, Menlo Park, California, USA
	The first in situ high resolution field emission (FE) imaging experiment has been carried out on an L-band photocathode gun test stand at Argonne Wakefield Accelerator facility (AWA). Separated strong emitters have been observed to dominate the field emission. Field enhancement factor, beta, of small regions on the cathode has been measured with the imaging system. It is shown that most strong emitters overlaps with the high beta regions. The post surface examinations reveal the origins of ~75% strong emitters overlap with the spots where rf breakdown have occurred. Detailed results are presented in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW015
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TUPOW018	Tunable High-Intensity Electron Bunch Train Production Based on Nonlinear Longitudinal Space Charge Oscillation	radiation, electron, space-charge, gun	1782
	Z. Zhang, H.B. Chen, Y.-C. Du, W.-H. Huang, J. Shi, X.L. Su, C.-X. Tang, Q.L. Tian, D. Wang, W. Wang, L.X. Yan, L.M. Zheng, Z. Zhou TUB, Beijing, People's Republic of China W. Gai ANL, Argonne, Illinois, USA
	High peak current electron bunch trains with tunable terahertz (THz) spacing are produced and measured experimentally. An initial picosecond periodic modulation in the temporal profile of a relativistic electron beam is magnified by the longitudinal space charge forces. As opposed to trying to reduce its smearing effect for large beam current, we take advantages of the nonlinear space charge oscillation through controlling the plasma phase advance. The spacing of the bunch train can be varied continuously either by tuning the velocity bunching of a radio-frequency gun or by tuning the compression of a downstream magnetic chicane. The narrow-band μJ-level THz radiation from the bunch train are also measured with tunable central frequency of the spectral from ~0.5 THz to 1.6 THz. The bunch train measurements are consistent with the particle tracking simulations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW018
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TUPOW047	Generation of a Coherent Cherenkov Radiation by using Electron Bunch Tilting	radiation, electron, target, gun	1870
	K. Sakaue Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan R. Kuroda, Y. Taira AIST, Tsukuba, Ibaraki, Japan M. Nishida, M. Washio Waseda University, Tokyo, Japan J. Urakawa KEK, Ibaraki, Japan
	We have been developing a compact accelerator based a laser photocathode rf electron gun at Waseda University. Low emittance and short bunched electron beam can be generated from the gun. Also, the rf transverse deflecting cavity was developed for the bunch length measurement. We performed an experiment for generating a coherent Cherenkov radiation using bunch tilting. The rf transverse deflector can give a tilt for the electron bunch, and the tilt angle was set to the Cherenkov radiating angle which determined by the target refractive index. We successfully demonstrated a coherent Cherenkov radiation and the characterization of the radiation. The principle of coherent Cherenkov radiation generation, the experimental results and future prospective will be presented at the conference.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW047
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TUPOW053	Measurement of Terahertz Generation in a Metallic, Corrugated Beam Pipe	radiation, electron, dipole, laser	1889
	K.L.F. Bane SLAC, Menlo Park, California, USA S.P. Antipov ANL, Argonne, Illinois, USA M.G. Fedurin, K. Kusche, C. Swinson BNL, Upton, Long Island, New York, USA D. Xiang Shanghai Jiao Tong University, Shanghai, People's Republic of China
	Funding: Work supported by the Department of Energy, Office of Science, Office of Basic Energy Science, under Contract No. DE-AC02-76SF00515 A method for producing narrow-band THz radiation proposes passing an ultra-relativistic beam through a metallic pipe with small periodic corrugations. We present results of a measurement of such an arrangement at BNL's Advanced Test Facility (ATF). Our pipe was copper and was 5 cm long; the aperture was cylindrically symmetric, with a 1 mm (radius) bore and a corrugation depth (peak-to-peak) of 60 um. In the experiment we measured both the effect on the beam of the structure wakefield and the spectral properties of the radiation excited by the beam. We began by injecting a relatively long beam–-compared to the wavelength of the radiation–-to excite the structure, and then used a downstream spectrometer to infer the radiation wavelength. This was followed by injecting a shorter bunch, and then using an interferometer (also downstream of the corrugated pipe) to measure the spectrum of the induced THz radiation. Our experimental set-up was simple and not optimized for the efficient collection of the radiation by e.g. the use of tapered horns. As such it can be considered a proof-of-principle experiment. K. Bane and G. Stupakov, NIM A677 (2012) 67-73.
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TUPOW054	Characterization of a Sub-THz Radiation Source Based on a 3 MeV Electron Beam and Future Plans	electron, radiation, quadrupole, laser	1892
	A.V. Smirnov, R.B. Agustsson, T.J. Campese, Y.C. Chen, J.J. Hartzell, B.T. Jacobson, A.Y. Murokh, M. Ruelas RadiaBeam, Santa Monica, California, USA W. Berg, J.C. Dooling, L. Erwin, R.R. Lindberg, S.J. Pasky, N. Sereno, Y.-E. Sun, A. Zholents ANL, Argonne, Ilinois, USA Y. Kim KAERI, Jeongeup-si, Republic of Korea
	Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC-FOA-0007702) Design features and some past experimental results are presented for a sub-THz wave source employing the Advanced Photon Source's RF thermionic electron gun. The setup includes a compact alpha-magnet, four quadrupoles, a novel radiator, a THz transport line, and THz diagnostics. The radiator is composed of a dielectric-free, planar, over-sized structure with gratings. The gratings are integrated into a combined horn antenna and ~90° permanent bending magnet. The magnetic lattice enables operation in different modes, including conversion to a flat beam for efficient interaction with the radiating structure. The experiment described demonstrated the generation of narrow bandwidth THz radiation from a compact, laser and undulator-free, table-top system. This concept could be scaled to create a THz-sub-THz source capable of operating in long-pulse, multi-bunch, and CW modes. Additionally, the system can be used to remove unwanted time-dependent energy variations in longitudinally compressed electron bunches or for various time-dependent beam diagnostics. Plans for future experiments and upgrades are also discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW054
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TUPOY006	Improvement of Scanning Irradiation in Gunma University Heavy Ion Medical Center	extraction, ion, heavy-ion, acceleration	1914
	H. Souda, T. Kanai, K. Kikuchi, Y. Kubota, A. Matsumura, H. Shimada, M. Tashiro, K. Torikai, M. Torikoshi, S. Yamada, K. Yusa Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan T. Fujimoto AEC, Chiba, Japan E. Takeshita Kanagawa Cancer Center, Ion-beam Radiation Oncology Center in Kanagawa, Kanagawa, Japan
	Funding: Work collaborated with Mitsubishi Electric Corporation Ltd. Work supported by JSPS Kakenhi 26860395, Program for Cultivating Global Leaders in Heavy Ion Therapeutics and Engineering by MEXT of Japan. Gunma University Heavy Ion Medical Center (GHMC) is a compact heavy ion treatment facility* and have experienced 5 years of successful treatment operation. GHMC has 3 treatment room using broad beam (wobbling) irradiation system and 1 experimental irradiation room for the research and development of a spot-scanning irradiation. During the study toward the treatment, several improvements were done in both accelerator and irradiation system. For accelerators, slow extraction from a synchrotron using a transverse rf field is tested*. Compared with conventional extraction system of rf acceleration, ripples of the beam spill (peak to bottom ratio) is reduced from almost 100% to 60%; the deviation of the beam center position and the deviation of the beam size (1σ) are reduced to the order of 0.1 mm. For irradiation system, regularly operation for biological experiments has started form June 2014. In order to shorten the experiment time, 2-dimensional optimization of the irradiation planning was carried out. After the optimization, the irradiation time was reduced by 30% with keeping the dose uniformity within ±2.5%. T. Ohno et al., Cancers, 3, 4046 (2011) ** K. Noda et al., Nucl. Instrum. Meth. A492, 253 (2002)
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TUPOY019	Geant4 Simulations of Proton-induced Spallation for Applications in ADSR Systems	neutron, proton, target, simulation	1943
	S.C. Lee IIAA, Huddersfield, United Kingdom C. Bungau, R. Cywinski University of Huddersfield, Huddersfield, United Kingdom
	Neutron spallation is an efficient process for producing intense neutron fluxes that can be exploited in Accelerator Driven Subcritical Reactors (ADSRs) for energy production and the transmutation of nuclear waste. In order to assess the feasibility of spallation driven fission and transmutation we have simulated proton induced neutron production using GEANT4, initially benchmarking our simulations against published experimental neutron spectra produced from a thick lead target bombarded with 0.5 and 1.5 GeV protons. The Bertini and INCL models available in GEANT4, coupled with the high precision (HP) neutron model, are found to adequately reproduce the published experimental data. Given the confidence in the GEANT4 simulations provided by this benchmarking we have then proceeded to simulate neutron production as a function of target geometry and thence to some preliminary studies of neutron production in an ADSR with a geometry similar to that of the proposed Belgian MYRRHA project. This paper presents the results of our GEANT4 benchmarking and simulations.
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TUPOY047	Development of a Non-destructive Inspection System for Industrial and Societal Infrastructures with 950 keV/3.95 MeV Portable X-band Linac-based X-ray	linac, site, radiation, distributed	2011
	R. Yano The University of Tokyo, Tokyo, Japan J. Kusano Accuthera Inc., Kawasaki, Kanagawa, Japan M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
	Advanced maintenance for aging industrial and societal infrastructures such as chemical plant and bridge are strongly needed recently. For the purpose, we are developing, applying and upgrading the 950 keV/3.95 MeV X-band linac X-ray sources for the on-site inspection. Less than 1 MeV accelerators are available for on-site inspection and less than 3.95 MeV accelerators are allowable for only bridge on-site inspection. These systems can visualize in seconds inner states of infrastructures, such as crack of concrete, iron-reinforced rod/wire and other imperfections. By using the 950 keV system, we conducted the first inspection of the real bridge and evaluated degradation of pre-stressed concrete wires. We also demonstrated first on-site use of the 3.95 MeV system in Japan in 2015. We are also performing structural analysis to evaluate the degradation of strength. For more precise evaluation, we are going to carry out a partial angle CT to reconstruct a two-dimensional inner structure. We are going to present the results and strategy of degradation evaluation of the industrial and societal infrastructures by the 950 keV / 3.95 MeV X-ray sources.
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TUPOY053	In-Kind Contributions: A Prosperous Model of Procurement for Large-scale Science Projects	interface, controls, vacuum, site	2017
	R. Amirikas, P. Ghosh FAIR, Darmstadt, Germany
	The number of research infrastructures which are being built with significant amount of In-Kind Contributions (IKCs) from partners and stakeholders is on the increase. One of the main advantages of the utilization of IKCs in big science projects is to enable numerous partners with technological and scientific know-how participate directly in such projects. Thus, IKCs promote capacity building in technology and knowledge transfer of these partners. However, management and execution of IKCs are particularly challenging. The 2nd In-Kind Contributions Workshop (IKCW 2015) was organized by the Facility for Antiproton and Ion Research in Europe (FAIR) with the aim of sharing experiences on the procurement and management of large-scale international science projects through IKCs. This paper focuses on the analysis of the issues pertaining to how to best implement and execute IKCs from the initial phase of assignment until full delivery for both accelerator and experiments. Discussions held during IKCW 2015 are used to highlight these points further. The goal of this paper is to present the reader with a synopsis of the challenges and opportunities faced in procurement through IKCs.
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TUPOY055	Study on Electro-polishing of Nb Surface by Periodic Reverse Current Method with Sodium Hydroxide Solution	cavity, operation, SRF, cathode	2020
	J. Taguchi, A. Namekawa Nomura Plating Co, Ltd., Osaka, Japan H. Hayano, T. Saeki KEK, Ibaraki, Japan C.E. Reece, H. Tian JLab, Newport News, Virginia, USA
	Electropolishing is one of the best methods of Nb surface finishing of the superconducting cavity to obtain high accelerating gradient. Mixed solution of hydrofluoric acid and sulfuric acid is generally used in the electropolishing of Nb. But this solution is very dangerous and because the corrosion of the metal occurs by hydrofluoric acid, all equipment must be made of high density polyethylene or fluorocarbon resin. This causes the expensive cost of electropolishing instrument. In addition, this solution produces sulfur compound on the Nb surface in the electropolishing reaction. This sulfur compound can be field emission sources on the inner surface of cavity and degrades acceleration performance. In this poster, we report noble electropolishing method using periodic reverse current and sodium hydroxide solution. The reaction produces no sulfur content and the equipment is less expensive because the instrument can be made of usual plastic material. As the result of experiments with Nb-coupon samples, we found that the surface roughness is equivalent to the conventional electropolishing method.
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WEOAA03	Experimental Study on Optical Vortex from a Helical Undulator at UVSOR-III	undulator, radiation, synchrotron, synchrotron-radiation	2036
	M. Hosaka Nagoya University, Nagoya, Japan M. Katoh, N.S. Mirian UVSOR, Okazaki, Japan T. Konomi, N. Yamamoto KEK, Ibaraki, Japan K. Kuroda ISSP, Kashiwa-shi, Japan K. Miyamoto, S. Sasaki HSRC, Higashi-Hiroshima, Japan
	A relativistic electron in helical undulator emits an optical vortex which carries orbital angular momentum. Sasaki and McNulty predicted theoretically that higher harmonics of helical undulator is optical vortex* and the experimental verification was made at BESSY and UVSOR-III. Further, we have made a systematic study to characterize the optical vortex from a helical undulator at UVSOR-III. Synchrotron radiation in UV region from an optical klystron undulator system consisting of two APPLE-II helical undulators and a buncher was used for the experiment. Patterns resulting from inferences between two undulator radiation carrying different angular momentums were clearly observed. To investigate the optical properties of the radiation, diffraction experiments were carried out. Specific diffraction patterns due to the phase singularity in the radiation center were clearly observed. The experimental results are compared with simulation. S. Sasaki, I. McNulty, Phys. Rev. Lett. 100, 124801 (2008) J. Bahrdt et al., Phys. Rev. Lett. 111, 034801 (2013) * e.g. S. Sasaki et al., presented in SRI2015 (2015)
	Slides WEOAA03 [11.023 MB]
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WEOCA02	First Operational Experience with an Internal Halo Target at RHIC	target, operation, detector, collider	2070
	C. Montag BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. An internal halo target has been installed in the STAR detector at RHIC to extend the energy range towards lower energies and increase the event rates in the search for the critical point in the QCD phase diagram. We discuss geometric considerations that led to the present target layout and present first operational results.
	Slides WEOCA02 [1.605 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOCA02
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WEOBB01	Single Micron Single-Bunch Turn-by-Turn BPM Resolution Achieved at NSLS-II	storage-ring, operation, collective-effects, Windows	2095
	B. Podobedov, W.X. Cheng, K. Ha, Y. Hidaka, J. Mead, O. Singh, K. Vetter BNL, Upton, Long Island, New York, USA
	NSLS-II state-of-the-art BPMs provide a single micron turn-by-turn BPM resolution for any bunch train of reasonable intensity. For certain beam dynamics studies a similar, or even better, resolution is desired for a single-, or a few-bunch fill, which is not yet available with our standard BPM signal processing. This paper describes our experience with more advanced BPM ADC signal processing which allowed us to significantly improve turn-by-turn BPM resolution in single bunch mode down to the level of about one micron at ~1 nC/bunch. We also present the examples of machine studies that benefit from this BPM performance enhancement.
	Slides WEOBB01 [2.565 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOBB01
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WEOBB02	Status of Wakefield Monitor Experiments at the CLIC Test Facility	detector, emittance, pick-up, electron	2099
	R.L. Lillestøl, E. Adli, J. Pfingstner University of Oslo, Oslo, Norway N. Aftab, S. Javeed PINSTECH, Islamabad, Pakistan R. Corsini, S. Döbert, W. Farabolini, A. Grudiev, W. Wuensch CERN, Geneva, Switzerland
	For the very low emittance beams in CLIC, it is vital to mitigate emittance growth which leads to reduced luminosity in the detectors. One factor that leads to emittance growth is transverse wakefields in the accelerating structures. In order to combat this the structures must be aligned with a precision of a few um. For achieving this tolerance, accelerating structures are equipped with wakefield monitors that measure higher-order dipole modes excited by the beam when offset from the structure axis. We report on such measurements, performed using prototype CLIC accelerating structures which are part of the module installed in the CLIC Test Facility 3 (CTF3) at CERN. Measurements with and without the drive beam that feeds rf power to the structures are compared. Improvements to the experimental setup are discussed, and finally remaining measurements that should be performed before the completion of the program are summarized.
	Slides WEOBB02 [2.928 MB]
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WEOBB03	A Non-destructive Profile Monitor Using a Gas Sheet	electron, ion, proton, target	2102
	N. Ogiwara, Y. Hikichi, J. Kamiya, M. Kinsho, Y. Namekawa JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan M. Fukuda, K. Hatanaka, T. Shima RCNP, Osaka, Japan
	We are developing a dense gas-sheet target to realize a non-destructive and fast-response beam profile monitor for 3 GeV rapid cycling synchrotron (RCS) in the J-PARC. This time, to demonstrate the function of the gas sheet for measuring the 2 dimensional profiles of the accelerated beams, the following experiments were carried out: 1) The gas sheet with a thickness of 1.5 mm and the density of 2×10^-4 Pa was generated by the combination of the deep slit and the thin slit. Here, the gas sheet was produced by the deep slit, and the shape of the sheet was improved by the thin slit. 2) For the electron beam of 30 keV with a diameter greater than 0.35 mm, the position and the two-dimensional profiles were well measured using the gas sheet. 3) Then the profiles of the 400 MeV proton beam with a current of 1×10-6 A was well measured, too.
	Slides WEOBB03 [4.718 MB]
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WEPMB019	Magnetic Fields in Bulk, Film, and Multilayer Superconductors in Front of a Multi-turn Coil	photon	2164
	T. Kubo KEK, Ibaraki, Japan
	Funding: JSPS Young Scientists(B) #26800157, JSPS Challenging Exploratory Research #26600142, MEXT Photon and Quantum Basic Research Coordinated Development Program The magnetic field distribution formulae in a bulk superconductor, a superconducting film, and an SIS multilayer structure in front of a multi-turn coil are derived, which may be useful for a detailed analysis in a vortex field measurement by using the third harmonic method. * See for example the invited oral presentation by T. Kubo, "Theory of multilayer coating for proof-of-concept experiments", at SRF2015 ** C.Z.Antoine et al., Appl. Phys. Lett. 102, 102603 (2013)
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WEPMB021	Construction of Measurement System for Superconducting Characteristics on Thin-film Samples at KEK	cavity, solenoid, operation, SRF	2167
	T. Saeki, H. Hayano, T. Kubo KEK, Ibaraki, Japan Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan H. Oikawa Utsunomiya University, Utsunomiya, Japan
	We set up a measurement system for superconducting characteristics on thin-film samples at KEK. The system includes small-sized and middle-sized cryostats, where critical temperature, critical magnetic field, Residual Resistiviy Ratio (RRR), Superconducting RF (SRF) resistivity can be measured on thin-film samples. A small-sized cryostat has a compact refrigerator to cool down samples for the measurements of critical temperature and RRR. On the other had, we can cool down various setups with a middle-sized cryostat by using liquid helium. A thin-film sample is set into a mushroom cavity and the SRF characteristics of the thin-film sample can be measured. In another setup, a sample is set with a small coil and the third harmonic measurement is done on the sample around the critical temperature. Finally, a thin-film sample is set into the bore-center of superconducting magnet and the magnetization of sample is measured with external magnetic field around the critical temperature. This article presents the details of the system and some measurements of samples by the system.
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WEPMB029	Research of Nitrogen Doping at IHEP	niobium, cavity, vacuum, electron	2186
	P. Sha Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China J.P. Dai IHEP, Beijing, People's Republic of China F. Jiao PKU, Beijing, People's Republic of China
	Funding: Work funded by National Natural Science Foundation of China, Grant No. 11505197 Recently, nitrogen doping (N-doping) technology has been proved to increase Q0 of superconducting cavity obviously, which lowers the BCS surface resistance. After N-doping, Q0 of 9-cell 1.3 GHz cavity can be increased to 310¹⁰ at Eacc = 16 MV/m, while 1.51010 without N-doping [1]. Since 2013, there have been over 60 cavities nitrogen doped at FNAL, JLAB and Cornell. The Circular Electron Collider (CEPC) has been proposed by IHEP in China, while requests Q0=4e10@Eacc=15.5 MV/m for 650 MHz cavity. It's hard to achieve without N-doping. So research of N-doping was begun in cooperation with Peking University in early 2015. Experiments of niobium samples have showed that nitrogen concentration at niobium surface increased a lot after N-doping. After then, several single-cell 1.3 GHz cavities completed vertical tests, but there're no successful test results of Q0 increasing, yet.
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WEPMB057	First Results of Magnetic Field Penetration Measurements on Multilayer S-I-S Structures	SRF, cavity, niobium, target	2245
	O.B. Malyshev, K.D. Dumbell, L. Gurran, N. Pattalwar, S.M. Pattalwar, R. Valizadeh STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom A.V. Gurevich ODU, Norfolk, Virginia, USA L. Gurran Lancaster University, Lancaster, United Kingdom L. Gurran Cockcroft Institute, Lancaster University, Lancaster, United Kingdom O.B. Malyshev, S.M. Pattalwar, R. Valizadeh Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The performance of superconducting RF cavities made of bulk Nb is limited by a breakdown field of Bp=~200 mT, close to the superheating field for Nb. A potentially promising solution to enhance the breakdown field of the SRF cavities beyond the intrinsic limits of Nb is a multilayer coating suggested in [1]. In the simplest case, such a multilayer may be a superconductor-insulator-superconductor (S-I-S) coating, for example, bulk niobium (S) coated with a thin film of insulator (I) followed by a thin layer of another superconductor (S) which could be e.g. dirty niobium [2]. Here we report the first results of our measurements of field penetration in Nb thin films and Nb-AlN-Nb multilayer samples at 4.2 K using the magnetic field penetration facility designed, built and tested in ASTeC.
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WEPMR019	Development of Plasma Cleaning at Cornell University	plasma, cavity, SRF, superconductivity	2302
	G.M. Ge, F. Furuta, M. Liepe, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Cornell University is developing the plasma cleaning technology as an alternative cleaning technique for SRF cavity surface preparation. In experiments, we successfully ignited the plasma in a single-cell SRF cavity. However the experiments were limited by the peak electric-fields in the RF coupler. In this paper, we show the analysis of the limitation and propose a new design of the coupler which can eliminate the limitation.
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WEPMR028	Studies on the Field Dependence of the BCS Surface Resistance	cavity, SRF, niobium, radio-frequency	2335
	J.T. Maniscalco, D. Gonnella, G.H. Hoffstaetter, P.N. Koufalis, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Experiments have shown that the temperature-dependent portion of the RF surface resistance of SRF materials also exhibits a dependence on the magnitude of the surface field, manifested as a "Q-slope" or "anti-Q-slope" in the medium field region. Recent theoretical work proposes an explanation of the anti-Q-slope in dirty-limit superconductors. In this report, we compare theoretical predictions with the results of systematic experimental studies on the RF field dependence of the surface resistance using 1.3 GHz niobium SRF cavities with a wide range of mean free paths. We find very good agreement between theory and experiment in the dirty limit, with some divergence as the cavities approach the clean limit.
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WEPMR043	Analysis of Electrical Energy Consumption of Accelerator Reserach Facilities	operation, HOM, framework, neutron	2370
	J. Stadlmann GSI, Darmstadt, Germany D. Batorowicz, C. Fuhr, J. Hanson, S. Leis TUD, Darmstadt, Germany M. Seidel PSI, Villigen PSI, Switzerland
	Funding: The work is part of EuCARD-2, partly funded by the European Commission, GA 312453. Optimization of energy efficiency and utilization of renewable energy sources has become a major focus of political and social policies, leading to increasing energy cost not only in Germany but also in the European energy market. Simultaneously the energy demand of future accelerator projects is estimated to rise compared to existing facilities, leading to overall increased energy costs. Energy efficiency could counteract this trend by reducing energy consumption for a given research goal. This work aims to find recommendations for saving potential in existing research accelerators as well as guidelines for construction of future facilities. In order to identify and develop key figures for comparison between several international particle accelerator facilities, data has been collected by a questionnaire developed in cooperation between GSI and TUD, Darmstadt. We present the first results of it's evaluation.
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MOPMB002

First Measurements of Coherent Smith-Purcell Radiation in the SOLEIL Linac

detector, linac, radiation, operation

69

N. Delerue, J. Barros, S. Jenzer, V. Khodnevych, M.S. Malovytsia
LAL, Orsay, France
N. Hubert, M. Labat
SOLEIL, Gif-sur-Yvette, France
V. Khodnevych
National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine
M.S. Malovytsia
KhNU, Kharkov, Ukraine

Funding: The authors are grateful for the funding received from the French ANR (contract ANR-12-JS05-0003-01).
An experiment to measure the Coherent Smith-Purcell radiation has been installed in the SOLEIL Linac. Its aim is to produce a map of Smith-Purcell radiation emissions in several planes and compare it with theoretical predictions. Coherent Smith Purcell radiation is produced when a grating is brought close from a sufficiently short charged particles beam. The experiment consist of two detectors with 5 degrees of freedom. These two detectors can be moved around the emission point to measure the intensity of the radiation at different locations. Radiation maps are recorded parasitically by moving the detectors around during normal linac operations.

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MOPMB004

Comparison of the Smith-purcell Radiation Yield for Different Models

radiation, electron, simulation, detector

75

M.S. Malovytsia, N. Delerue
LAL, Orsay, France
M.S. Malovytsia
KhNU, Kharkov, Ukraine

Funding: The authors are grateful for the funding received from the French ANR (contract ANR-12-JS05-0003-01) and the IDEATE International Associated Laboratory (LIA) France-Ukraine.
Smith-Purcell radiation is used in several applications including the measurement of the longitudinal profile of electron bunches. A correct reconstruction of such profile requires a good understanding of the underlying model. We have compared the leading models of Smith-Purcell radiation and shown that they are in agreement within the experimental errors.

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MOPMB007

Diamond Sensor Resolution in Simultaneous Detection of 1,2,3 Electrons at the PHIL Photoinjector Facility at LAL

electron, detector, simulation, target

84

V. Kubytskyi, P. Bambade, S. Barsuk
LAL, Orsay, France
O.A. Bezshyyko, V. Krylov, V. Rodin
National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine

In this paper, we present experimental and numerical studies of the signals from the Poisson-like distributions resulting from electrons incident on a diamond sensor placed near the exit of the PHIL photoinjector facility at LAL. The experiments were performed at the newly commissioned Low Energy Electron TECHnology (LEETECH) platform at PHIL. Bunches of 10x9 electrons are first generated and accelerated to 3.5 MeV by PHIL. The electrons are then filtered in LEETECH by a system of collimators, using a dipole magnet for momentum selection. The diamond sensor is located immediately after the output collimator to collect electrons in the range 2.5-3 MeV. We show that with standard scCVD diamonds of 500 micrometers thickness, the energy losses from the first three MIP (minimum ionizing particle) electrons are clearly resolved. We did not observe distinguishable peaks in cases when a significant fraction of the incident electrons had energies below a MIP. The described technique can be used as complementary approach for calibration of diamond detectors as well as to diagnose and help control accelerated beams in a regime down to a few particles.

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MOPMB029

Development Status of Linear Focal Cherenkov Ring Camera

electron, vacuum, laser, photon

152

K. Nanbu, T. Abe, H. Hama, F. Hinode, S. Kashiwagi, T. Muto, I. Nagasawa, H. Saito, K. Takahashi, C. Tokoku
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan

Linear focal Cherenkov ring camera (LFC-Camera) has been developed for single shot measurement of longitudinal phase space distribution of quasi-relativistic electron beam, where the electron's velocity still depends on its energy. The LFC-camera employs velocity dependence of opening angle of Cherenkov light produced by electron beam to observe its energy (momentum) distribution. Since the Cherenkov light contains the time information if the radiator medium is thin enough, we can get the longitudinal phase space distribution measuring both time and energy spectra simultaneously using a streak camera. We employ a thin silica aerogel with water-free hydrophobic treatment as Cherenkov radiator. We have evaluated characteristics of the silica aerogel radiator, and demonstration of the LFC-camera at a beam diagnosis section of t-ATCS is being proceeded.

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MOPMB030

Development of an EO Sampling Method for THz Pulse Detection

laser, radiation, polarization, electron

155

T. Toida, M. Washio, R. Yanagisawa
Waseda University, Tokyo, Japan
K. Sakaue
Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan

We have been studying an S-band Cs-Te photo-cathode rf gun at Waseda Univ. The high quality electron beam produced by the rf gun is used to generate a high-power coherent terahertz pulse via Cherenkov radiation. This terahertz pulse can be applied to terahertz imaging and material analysis. As a preliminary step towards material analysis, we conducted experiments on terahertz time domain spectroscopy by EO sampling method to reveal major parameters of the terahertz pulse such as the pulse form and the spectrum. EO sampling method has high frequency response and suitable for high peak power terahertz pulses. In terahertz time domain spectroscopy, the duration of the probe pulse needs to be much faster than that of the terahertz pulse. Therefore, we developed a mode locked Yb-fiber laser based on nonlinear polarization rotation as a reliable and cost-effective ultra-fast probe light source. The laser generates 3.80 ps chirped pulses which are compressed to 213 fs with a grating pair. In this conference, we will report the performance of the Yb-fiber laser and results of EO sampling experiments.

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MOPMB048

Bunch Length Measurement at Bunch by Bunch in Harmonics Method at Shanghai SSRF Storage Ring

injection, storage-ring, electron, synchrotron-radiation

199

L.W. Duan, Y.B. Leng, R.X. Yuan
SINAP, Shanghai, People's Republic of China
N. Zhang
SSRF, Shanghai, People's Republic of China

Harmonics method in frequency domain is an effective and inexpensive bunch length measurement method. With advances in technology, it is possible to do bunch length measurement at bunch by bunch using electronic method. We design and make an electronic system to realize metering at bunch by bunch, and believe it has reasonable bunch length resolution. All selected harmonic signals will be mixed down to 500 MHz and digitized at bunch-by-bunch rate by a multi-channel DBPM processor. The primary beam experiment results will be presented and discussed in this paper.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB048

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MOPMB050

Design of Ultra-wideband Amplifier in RF Front End for Bunch-by-bunch Measurement

power-supply, simulation, impedance, synchrotron-radiation

205

Y. Yang, Y.B. Leng, Y.B. Yan
SSRF, Shanghai, People's Republic of China

RF front end is one of the key technologies in beam diagnosis, especially in bunch-by-bunch measurement at storage ring. This paper gives the design of ultra-wideband amplifier in RF front end for bunch-by-bunch measurement at SSRF. Simulation have been done to verify the performance of this design.

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MOPMB051

Cavity BPM Performance Online Evaluation using PCA Method

cavity, electron, factory, coupling

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.

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MOPMB054

A High Sensitivity Faraday Cup for Ultrashort Electron Bunches

electron, simulation, gun, laser

214

S. Setiniyaz, I.H. Baek, B.A. Gudkov, B. Han, K.H. Jang, Y.U. Jeong, H.W. Kim, S.V. Miginsky, J.H. Nam, S. Park, N. Vinokurov
KAERI, Daejon, Republic of Korea
S.V. Miginsky, N. Vinokurov
BINP SB RAS, Novosibirsk, Russia

The UED (Ultrafast Electron Diffraction) beamline of KAERI (Korea Atomic Energy Research Institute) WCI (World Class Institute) Center has been successfully commissioned. A S-band co-axial RF photogun with 1.5 cylindrically symmetric cells was used to remove multiple modes of the electric filed inside the cavity. It is designed to generate sub-picosecond electron bunches with energy up to 3.3~MeV. We have developed a system consists of an in-air Faraday cup (FC) and a preamplifier for charge measurement. Tests performed utilizing 3.3~MeV electrons show the system were able to measure ultrashort bunches with tens of femtosecond pulse duration at 10 fC sensitivity. In this paper, we shall present the design, calibration and test results of this system.

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MOPMB057

Automatic Microbeam Focusing for X-Ray Microbeam Experiments at the 4B Beamline of Pohang Light Source-II

focusing, controls, operation, LabView

220

K.H. Gil, H. J. Choi, J.-H. Lim
PAL, Pohang, Republic of Korea

The 4B beamline of the Pohang Light Source-II performs X-ray microdiffraction and microfluorescence experiments using X-ray microbeams. When performing X-ray micro-experiments, an X-ray microbeam should first be prepared. Up to recently, the microbeams with vertical and horizontal sizes (full width at half maximum) of less than 3 μm have been achieved, by manually adjusting the translations and pitch angles of the vertically and horizontally focusing mirrors, in a Kirkpatrick'Baez (K-B) mirror system. In this research, we developed a program that automates the complex and cumbersome process of microbeam focusing, divided into half-cutting and focusing phases. The developed program was applied to the 4B beamline and enabled the focusing of an X-ray beam to a minimum size within one hour. This paper introduces the algorithms of the program and also examines its performance.

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MOPMR003

Electron Bunch Length Measurement Using Coherent Radiation Source of fs-THz accelerator at Pohang Accelerator Laboratory

radiation, electron, linac, target

235

J.H. Ko, I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea
S.H. Jung, H.-S. Kang, I.S. Ko, J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

A Michelson interferometer was installed at the femtosecond (fs) terahertz (THz) Accelerator of Pohang Accelerator Laboratory(PAL) to measure a subpicosecond order electron bunch length. To measure an ultra-short electron bunch length, we use reconstruction process and fast fourier transform. Currently, we are generating THz radiation with the pulse energy of 7μJ by means of coherent transition radiation (CTR) from a 65-MeV electron beam of the fs-THz accelerator. In this paper, we show the how to make a longitudinal distribution of electron bunch and the radiation intensity difference between CTR and Coherent edge radiation (CER) for nondestructive electron bunch length measurement. And we report the measurement methods to get the fine electron bunch length information.

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MOPMR010

The Development of Scintillating Screen Detector for Beam Monitoring at the KHIMA Project

proton, ion, cyclotron, heavy-ion

244

S.Y. Noh, S.D. Chang, J.G. Hwang
KIRAMS/KHIMA, Seoul, Republic of Korea
G. Hahn, T.K. Yang
KIRAMS, Seoul, Republic of Korea

Funding: NRF-2014M2C3A1029534
It is important to measure the beam propeties such as position, size and intensity, when we control the medical beam qualities, So we developed the scintillation screen monitor used for beam profile monitoring and it will be installed at High Energy Beam Transport(HEBT) section to measure the beam parameters. This system consists of a terbium-doped gadolinium oxysulfide(Gd2O2S:Tb) phosphor screen and high speed charge coupled device camera. The CCD camera has the maximum 90 frame rate and 659 X 494 pixel resolution. This Camera is mounted at distance of 260mm from the center of the scintillation screen and with the angle of 45 degree to the scintillation screen which is mounted at the angle of 45 degree to the beam axis. The image analysis program was written in National Instruments LabVIEW using IMAQ driver. To reduce the image processing time, we optimized the prcessing flow and used LabVIEW built-in function. To evaluate this system, we measured the beam size and center position of the beam at KIRAMS on 50MeV cyclotron. In this paper, we present the manufacture of beam profile system based on a scintillating screen monitor and the in-beam test results of it.

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MOPMR023

Surface Characterization and Field Emission Measurements of Copper Samples inside a Scanning Electron Microscope

electron, controls, vacuum, radio-frequency

283

J. Ögren, V.G. Ziemann
Uppsala University, Uppsala, Sweden
S.H.M. Jafri, K. Leifer
Uppsala University, Department of Engineering Sciences, Uppsala, Sweden

Vacuum breakdown in normal-conducting accelerating structures is a limiting factor for high gradient acceleration. Many aspects of the physics governing the breakdown process and its onset are yet to be fully understood. At Uppsala University we address these questions with an in-situ experimental setup mounted in an environmental scanning electron microscope. It consists of a piezo motor driven tungsten needle and a sample surface mounted on a piezo stage, allowing for nano-meter 3D-position control. One of the piezo motors controls the needle-sample gap while the two other scan across the surface. A DC-voltage up to 1 kV is applied across the gap and field emission currents from a copper surface are measured with an electrometer. Here we present the setup and some initial results.

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MOPMR025

Beam Size Estimation from Luminosity Scans at the LHC During 2015 Proton Physics Operation

luminosity, emittance, proton, operation

290

M. Hostettler, G. Papotti
CERN, Geneva, Switzerland
M. Hostettler
LHEP, Bern, Switzerland

As a complementary method for measuring the beam size for high-intensity beams at 6.5 TeV flat-top energy, beam separation scans were done regularly at the CERN Large Hadron Collider (LHC) during 2015 proton physics operation. The luminosities measured by the CMS experiment during the scans were used to derive the convoluted beam size and orbit offset bunch-by-bunch. This contribution will elaborate on the method used to derive plane-by-plane, bunch-by-bunch emittances from the scan data, including uncertainties and corrections. The measurements are then compared to beam size estimations from absolute luminosity, synchrotron light telescopes, and wire scanners. In particular, the evolution of the emittance over the course of several hours in collisions is studied and bunch-by-bunch differences are highlighted.

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MOPMR041

Experimental and Theoretical Studies of the Properties of Coherent Smith-Purcell Radiation

radiation, polarization, background, electron

344

F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, A. Reichold
JAI, Oxford, United Kingdom
J. Barros, N. Delerue
LAL, Orsay, France
R. Bartolini
DLS, Oxfordshire, United Kingdom
C.I. Clarke
SLAC, Menlo Park, California, USA

Funding: This work was supported (in parts) by the UK Science and Technology Facilities Council (STFC UK) through grant ST/M003590/1 and The Leverhulme Trust through the International Network Grant IN-2015-012
Previous studies have demonstrated that coherent Smith-Purcell radiation (cSPr) can be used for relativistic electron bunch time profile reconstruction at pico-second and femtosecond scales. The E203 experiments undertaken in May 2015 at FACET (SLAC) were dedicated to the study of some properties of cSPr, namely the azimuthal distribution and the polarization of the radiation. The experimental set up description which allowed such studies will be presented along with the results. To understand the experimental data both semi-analytical and numerical models were studied. The semi-analytical approach was based on the surface-current model, and the 3D particle-in-cell code VSim was used for numerical modeling. The experimental and theoretical studies are compared.

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MOPMW028

Progress on the MICE RF Module at LBNL

cavity, vacuum, operation, coupling

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.

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MOPMW030

High Powered Tests of Dielectric Loaded High Pressure RF Cavities for Use in Muon Cooling Channels

accelerating-gradient, cavity, radio-frequency, plasma

460

B.T. Freemire
IIT, Chicago, Illinois, USA
D.L. Bowring, A. Moretti, D.W. Peterson, A.V. Tollestrup, Y. Torun, K. Yonehara
Fermilab, Batavia, Illinois, USA
A.V. Kochemirovskiy
University of Chicago, Chicago, Illinois, USA
Y. Torun
Illinois Institute of Technology, Chicago, Illlinois, USA

Funding: This work is supported by the Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359.
Bright muon sources require six dimensional cooling to achieve acceptable luminosities. Ionization cooling is the only known method able to do so within the muon lifetime. One proposed cooling channel, the Helical Cooling Channel, utilizes gas filled radio frequency cavities to both mitigate RF breakdown in the presence of strong, external magnetic fields, and provide the cooling medium. Engineering constraints on the diameter of the magnets within which these cavities operate dictate the radius of the cavities be decreased at their nominal operating frequency. To accomplish this, one may load the cavities with a larger dielectric material. Alumina of purities ranging from 96 to 99.8% was tested in a high pressure RF test cell at the MuCool Test Area at Fermilab. The results of breakdown studies with pure nitrogen gas, and oxygen-doped nitrogen gas indicate the peak surface electric field on the alumina ranges between 10 and 15 MV/m. How these results affect the design of a prototype cooling channel cavity will be discussed.

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MOPMW033

Acoustic Localization of RF Cavity Breakdown: Status and Progress

cavity, collider, simulation, status

470

P.G. Lane, P. Snopok, Y. Torun
Illinois Institute of Technology, Chicago, Illinois, USA
A.V. Kochemirovskiy
University of Chicago, Chicago, Illinois, USA

Current designs for muon accelerators require high-gradient RF cavities to be placed in solenoidal magnetic fields. These fields help contain and efficiently reduce the phase space volume of source muons in order to create a usable muon beam for collider and neutrino experiments. It has been found that placing normal conducting RF cavities in strong magnetic fields reduces the threshold at which RF cavity breakdown occurs. To aid the effort to study RF cavity breakdown in magnetic fields, it would be helpful to have a diagnostic tool which can localize the source of breakdown sparks inside the cavity. These sparks generate thermal shocks to a small region of the inner cavity wall that can be detected and localized using microphones attached to the outer cavity surface. Presented here are the algorithms for and results from localizing simulated and experimental acoustic data from the Modular Cavity at the MuCool Test Area at Fermilab.

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MOPMW038

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

cavity, cryogenics, electron, coupling

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.

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MOPMW040

Electron Beam Excitation of a Surface Wave in mm-Wave Open Accelerating Structures

electron, detector, vacuum, simulation

494

M. Dal Forno, G.B. Bowden, C.I. Clarke, V.A. Dolgashev, M.J. Hogan, D.J. McCormick, A. Novokhatski, B.D. O'Shea, S.G. Tantawi, S.P. Weathersby
SLAC, Menlo Park, California, USA
B. Spataro
INFN/LNF, Frascati (Roma), Italy

Funding: Work supported by the US DOE under contract DE-AC02-76SF00515.
As part of research on the physics of rf breakdowns we performed experiments with high gradient traveling-wave mm-wave accelerating structures. The accelerating structures are open, composed of two identical halves separated by an adjustable gap. The electromagnetic fields are excited by an ultra-relativistic electron beam. We observed that a confined travelling-wave mode exists in half of the accelerating structure. The experiments were conducted at FACET facility at SLAC National Accelerator Laboratory. Depending on the gap width, the accelerating structure had beam-synchronous frequencies that vary from 90 to 140 GHz. When we opened the gap by more than half wavelength the synchronous wave remains trapped. Its behavior is consistent with the so called "surface wave". We characterized this beam-wave interaction by several methods: measurement of the radiated rf energy with the pyro-detector, measurement of the spectrum with an interferometer, measurement of the beam deflection by using the beam position monitors and profile monitor.

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MOPMW041

Measurements of RF Breakdowns in Beam Driven mm-Wave Accelerating Structures

vacuum, electron, detector, collider

497

M. Dal Forno, G.B. Bowden, C.I. Clarke, V.A. Dolgashev, M.J. Hogan, D.J. McCormick, A. Novokhatski, S.G. Tantawi, S.P. Weathersby
SLAC, Menlo Park, California, USA
B. Spataro
INFN/LNF, Frascati (Roma), Italy

Funding: Work supported by the US DOE under contract DE-AC02-76SF00515
We studied the physics and properties of rf breakdowns in high gradient traveling-wave accelerating structures at 100 GHz. The structures are open, made of two halves with a gap in between. The rf fields were excited in the structure by an ultra-relativistic electron beam generated by the FACET facility at the SLAC National Accelerator Laboratory. We observed rf breakdowns generated in the presence of GV/m scale electric fields. We varied the rf fields excited by the FACET bunch by moving structure relative to the beam and by changing the gap between structure halves. Reliable breakdowns detectors allowed us to measure the rf breakdown rate at these different rf parameters. We measured radiated rf energy with a pyro-detector. When the beam was off-axis, we observed beam deflection in the beam position monitors and on the screen of a magnetic spectrometer. The measurements of the deflection allowed us to verify our calculation of the accelerating gradient.

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MOPMW044

Design of an RF Device to Study the Multipactor Phenomenon

cavity, simulation, electron, multipactoring

507

D. Amorim
Grenoble-INP Phelma, Grenoble, France
J.-M. De Conto, Y. Gómez Martínez
LPSC, Grenoble Cedex, France

Multipacting is a parasitic electron avalanche process that may occur in RF devices such as cavities or couplers. As it can be detrimental to the operation of these devices, the accelerator group at LPSC is currently designing a coaxial resonant cavity in order to study this phenomenon. In order to determine the measurable parameters on the cavity, calculations were performed and validated with numerical simulations. In a second time multipacting simulations were conducted to determine if the experiment will allow to observe multipacting.

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MOPMY016

Quadrature Directional Coupling Method for Precise RF Power Measurement

coupling, radio-frequency, feedback, controls

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.

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MOPOR037

Beam Halo Measurements using Vibrating Wire at the KOMAC

proton, target, laser, neutron

680

D. Choe, M. Chung, S.Y. Kim
UNIST, Ulsan, Republic of Korea
S.G. Arutunian, A.V. Margaryan
ANSL, Yerevan, Armenia
E.G. Lazareva
YSU, Yerevan, Armenia

In high-intensity particle accelerators, due to the fact that preventing beam loss plays a crucial role in con-ducting any experiments, it is important to measure and control the beam halo. Fortunately, it is feasible nowadays to measure the beam halo region thanks to the development of several sensitive beam scanning methods, including the vibrating wire technique. Since the vibrating wire is exceptionally sensitive to the heat deposition by the beam particles, it can be used to scanning the beam profile. This study will be concentrated on the precise beam profile measurement using the vibrating wire at the Korea Multi-Purpose Accelerator Complex (KOMAC) facility. First, we describe the best condition to construct beam profile measurement experiment. Finally, we present the results of the beam halo measurements performed with 20 MeV proton beam at the KOMAC facility

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MOPOR043

High-gradient Structures for Proton Energy Boosters

booster, linac, proton, cavity

692

S.S. Kurennoy, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV can improve radiography resolution ~10 times. The best current practice to achieve this energy boost is to employ superconducting (SC) RF cavities with gradients about 15 MV/m after the existing linac, which results in a long and expensive booster. We propose accomplishing the same with a room-sized booster based on high-gradient (100s MV/m) room-temperature RF accelerating structures operating at low duty factors. Such high-gradient (HG) structures at very high RF frequencies have been demonstrated for electrons. However, they have never been used for protons because typical RF wavelengths are smaller than the proton bunch length. This is not a problem for proton radiography (pRad): a train of very short proton bunches with the same total length (10s ps) and charge as the original proton bunch will work as well, i.e., will create one radiography frame. Such a compact HG pRad booster can also be about an order of magnitude cheaper than the SC one. We explore feasibility of HG structures for protons and their application for a compact pRad booster at LANSCE.

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MOPOW049

Implementation of a Corrugated-Plate Dechirping System for GeV Electron Beam at LCLS

FEL, electron, controls, laser

824

M.A. Harrison, P. Frigola, J.D. McNevin, A.Y. Murokh, M. Ruelas
RadiaBeam Systems, Santa Monica, California, USA
A.M. Babbitt, M. Carrasco, A. Cedillos, R.H. Iverson, P. Krejcik, T.J. Maxwell, '. Oven
SLAC, Menlo Park, California, USA

Funding: This work is supported by US DOE Grant No. DE-SC0009550.
A new corrugated-plate Dechirper was recently installed in the LCLS and underwent commissioning tests to gauge its efficacy in shaping the longitudinal phase space of bunches entering the FEL. Here, we describe in detail the completed four-meter LCLS Dechirper system along with a narrative of its construction. We detail the various challenges and lessons learned in the manufacturing and assembly of this first-of-its-kind device. An outlook on future designs is presented.

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MOPOY009

ELENA: Installations and Preparations for Commissioning

antiproton, electron, emittance, extraction

860

C. Carli, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, T. Eriksson, R. Ostojić, S. Pasinelli, G. Tranquille
CERN, Geneva, Switzerland
W. Oelert
Johannes Gutenberg University Mainz, Institut für Physik, Mainz, Germany

The Extra Low Energy Antiproton ring (ELENA) is a small 30 m circumference synchroton under construction at CERN to further decelerate antiprotons from the Antiproton Decelerator AD from 5.3 MeV to 100 keV. Controlled deceleration in a synchrotron equipped with an electron cooler to reduce emittances in all three planes will allow the existing AD experiments to increase substantially their antiproton capture efficiencies and render new experiments possible. Installation of the machine and lines needed for the commissioning of the ring are ongoing and commissioning is expected to start around mid-2016. The aim is to complete ELENA ring commissioning in November followed by the installation of new electrostatic transfer lines to existing experiments until autumn 2017. Status of ELENA installations and preparations for commissioning will be reported.

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MOPOY012

Space Charge Simulations in the Fermilab Recycler for PIP-II

simulation, space-charge, proton, booster

870

R. Ainsworth, P. Adamson, I. Kourbanis, E.G. Stern
Fermilab, Batavia, Illinois, USA

Proton Improvement Plan-II (PIP-II) is Fermilab's plan for providing powerful, high-intensity proton beams to the laboratory's experiments. Upgrades are foreseen for the recycler which will cope with bunches containing fifty percent more beam. Of particular concern is large space charge tune shifts caused by the intensity increase. Simulations performed using Synergia are detailed focusing on the space charge footprint.

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MOPOY032

Beam Twiss Measurement With Ws Including Space Charge Effect

space-charge, lattice, simulation, rfq

925

Y.L. Zhao, H. Geng, C. Meng, F. Yan
IHEP, Beijing, People's Republic of China

Wire Scanners (WS) are used to measure beam profile and calculate the transverse Twiss parameters at the entrance of MEBT1 in the CADS injector I test stand. As to data process, the traditional method with transfer map doesn't consider the space charge effect. But, as we know, space charge effect can't be neglected for high intensity accelerators. In this paper, optimization algorithm is used in beam emittance measurement.

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MOPOY060

Performance Analysis for the New g-2 Experiment at Fermilab

simulation, storage-ring, injection, dipole

996

D. Stratakis, M.E. Convery, C. Johnstone, J.A. Johnstone, J.P. Morgan, M.J. Syphers
Fermilab, Batavia, Illinois, USA
J.D. Crmkovic, W. Morse, V. Tishchenko
BNL, Upton, Long Island, New York, USA
N.S. Froemming
University of Washington, CENPA, Seattle, USA
M. Korostelev
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Korostelev
Lancaster University, Lancaster, United Kingdom

The new g-2 experiment at Fermilab aims to measure the muon anomalous magnetic moment to a precision of ±0.14 ppm ─ a fourfold improvement over the 0.54 ppm precision obtained in the g-2 BNL E821experiment. Achieving this goal requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we describe a muon capture and transport scheme that should meet this requirement. First, we present the conceptual design of our proposed scheme wherein we describe its basic features. Then, we detail its performance numerically by simulating the pion production in the (g-2) production target, the muon collection by the downstream beamline optics as well as the beam polarization and spin-momentum correlation up to the storage ring. The sensitivity in performance of our proposed channel against key parameters such as magnet apertures and magnet positioning errors is analyzed

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TUOAA03

Long Term Plans to Increase Fermilab's Proton Intensity to Meet the Needs of the Long Baseline Neutrino Program

proton, linac, booster, injection

1010

E. Prebys, P. Adamson, S.C. Childress, P. Derwent, S.D. Holmes, I. Kourbanis, V.A. Lebedev, W. Pellico, A. Romanenko, V.D. Shiltsev, E.G. Stern, A. Valishev, R.M. Zwaska
Fermilab, Batavia, Illinois, USA

Funding: This work is supported by the US Department of Energy under contract No. De-AC02-07CH11359.
The flagship of Fermilab's long term research program is the Deep Underground Neutrino Experiment (DUNE), located Sanford Underground Research Facility (SURF) in Lead, South Dakota, which will study neutrino oscillations with a baseline of 1300 km. The neutrinos will be produced in the Long Baseline Neutrino Facility (LBNF), a proposed new beam line from Fermilab's Main Injector. The physics goals of the DUNE require a proton beam with a power of roughly 2.5 MW at 120 GeV, which is roughly five times the current maximum power. This poster outlines the staged plan to achieve the required power over the next 15 years.

Slides TUOAA03 [4.129 MB]

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TUOBA02

ER@CEBAF - A High Energy, Multi-pass Energy Recovery Experiment at CEBAF

linac, operation, optics, electron

1022

F. Méot, I. Ben-Zvi, Y. Hao, P. Korysko, C. Liu, M.G. Minty, V. Ptitsyn, G. Robert-Demolaize, T. Roser, P. Thieberger, N. Tsoupas
BNL, Upton, Long Island, New York, USA
M.E. Bevins, S.A. Bogacz, D. Douglas, C.J. Dubbe, T.J. Michalski, F.C. Pilat, Y. Roblin, T. Satogata, M. Spata, C. Tennant, M.G. Tiefenback
JLab, Newport News, Virginia, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A high-energy, multiple-pass energy recovery (ER) experiment proposal, using CEBAF, is in preparation by a JLab-BNL collaboration. The experiment will be proposed in support of the electron-ion collider project (EIC) R&D going on at BNL. This new experiment extends the 2003, 1-pass, 1 GeV CEBAF-ER demonstration into a range of energy and recirculation passes commensurate with BNL's anticipated linac-ring EIC parameters. The experiment will study ER and recirculating beam dynamics in the presence of synchrotron radiation, provide opportunity to develop and test multiple-beam diagnostic instrumentation, and can also probe BBU limitations. This paper gives an overview of the ER@CEBAF project, its context and preparations.

Slides TUOBA02 [1.936 MB]

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TUOBB01

Demonstration of Current Profile Shaping using Double Dog-Leg Emittance Exchange Beam Line at Argonne Wakefield Accelerator

emittance, quadrupole, dipole, wakefield

1065

G. Ha, M.-H. Cho, W. Namkung
POSTECH, Pohang, Kyungbuk, Republic of Korea
M.E. Conde, D.S. Doran, W. Gai, G. Ha, K.-J. Kim, W. Liu, J.G. Power, Y.-E. Sun, C. Whiteford, E.E. Wisniewski, A. Zholents
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
P. Piot
Fermilab, Batavia, Illinois, USA

Emittance exchange (EEX) based longitudinal current profile shaping is the one of the promising current profile shaping technique. This method can generate high quality arbitrary current profiles under the ideal conditions. The double dog-leg EEX beam line was recently installed at the Argonne Wakefield Accelerator (AWA) to explore the shaping capability and confirm the quality of this method. To demonstrate the arbitrary current profile generation, several different transverse masks are applied to generate different final current profiles. The phase space slopes and the charge of incoming beam are varied to observe and suppress the aberrations on the ideal profile. We present current profile shaping results, aberrations on the shaped profile, and its suppression.

Slides TUOBB01 [5.032 MB]

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TUPMB008

Beam-Based Alignment for the Transport Line of CSNS

alignment, controls, DTL, linac

1121

Y. Li, Y.W. An, Z.P. Li, W.B. Liu, S. Wang
IHEP, Beijing, People's Republic of China

Beam-based alignment (BBA) techniques are important tools for beam orbit steering in linear accelerators or transfer lines. In this paper this technique and the control system application programs developed based on XAL platform were applied to the beam commissioning for Medium Energy Beam Transport (MEBT) of CSNS to get the transverse misalignments of beam position monitor (BPM) and quad. The results shows that the absolute values of BPMs offsets are less than 0.6 mm and quads offsets are less than 0.05 mm，that is much smaller than the tolerance of the misalignment.

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TUPMB009

Vibrating Wire Measurements for the XiPAF Permanent Magnet Quadrupoles

multipole, background, permanent-magnet, DTL

1124

B.C. Wang, 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
C.T. Du, X.W. Wang, L. Wu, Q.Z. Xing, S.X. Zheng
TUB, Beijing, People's Republic of China

Vibrating wire technique is a promising measure-ment method for small-aperture Permanent Magnet Quadrupoles (PMQs) in linear accelerators and scan-ning nuclear microprobes. In this paper, we describe the improved vibrating wire setup for measuring an individual PMQ with the minimum aperture of several millimeters. This setup is aiming at measuring the magnetic center. The advantage of this setup is that any mechanical measurement on the wire, which may be the main error source, is avoided. Experiments of the 20 mm-aperture Halbach-type PMQs for Xi'an Proton Application Facility (XiPAF) DTL has been carried out. The research results of the magnetic center measurements show a precision of about 10 μm and robustness against the background magnetic field. Results of the magnetic center and field multipoles measurements agree with the ones obtained from the rotating coil.

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TUPMB010

Magnetic Center Position and Tilt Angle of Quadrupole by Vibration Wire Method

quadrupole, radiation, alignment, superconductivity

1127

L. Wu, X. Guan, X.W. Wang, S.X. Zheng
TUB, Beijing, People's Republic of China
B.C. Wang
NINT, Xi'an, People's Republic of China
G. Xialing
CIAE, Beijing, People's Republic of China

Vibrating wire method and device are described to locate the magnetic center of a Quadrupole theoretically and experimentally. With rotating 180 degrees method, it is convenience to measure the position magnetic center from mechanical center. Tilt angle can also be measured because tilt of magnetic axis will cause the difference of measured magnetic center in different harmonic driving current frequency. Errors analysis shows that tilt of Quadrupole will cause the main error and improved device is described to adjust and measure the tilt angle to fix the errors caused by tilt.

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TUPMB049

Development of Separator Cooling System for Helium

cryogenics, radiation, controls, vacuum

1209

W.R. Liao, S.-H. Chang, W.-S. Chiou, P.S.D. Chuang, F. Z. Hsiao, H.C. Li, T.F. Lin, H.H. Tsai
NSRRC, Hsinchu, Taiwan

A helium phase separator with a condenser is under fabrication and assembled at National Synchrotron Radiation Research Centre (NSRRC). The objective of a helium phase separator with its condenser is to separate two-phase helium flow and to re-condense vaporized gaseous helium with a cryocooler of Gifford-McMahon type. We developed a 100 litre (ltr) helium phase separator with a small heat loss as a prototype. The experimental results for the total cooling capacity of the phase separator are 0.73 W at 1.67 bara, which includes the effect of thermal conduction and thermal radiation from the environment. The helium liquefaction rate is 2 ltr/day with a 100 ltr vessel. The mechanism of heat transfer in phase separator was investigated and discussed. This paper presents the experiment of helium liquefaction process of 100 ltr separator with condenser, which was a key component of the helium phase separator.

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TUPMB052

High Intensity Beam Test of Low Z Materials for the Upgrade of SPS-to-LHC Transfer Line Collimators and LHC Injection Absorbers

simulation, injection, proton, radiation

1218

F.L. Maciariello, O. Aberle, M.E.J. Butcher, M. Calviani, R. Folch, V. Kain, K. Karagiannis, I. Lamas Garcia, A. Lechner, F.-X. Nuiry, G.E. Steele, J.A. Uythoven
CERN, Geneva, Switzerland

In the framework of the LHC Injector Upgrade (LIU) and High-Luminosity LHC (HL-LHC) project, the collimators in the SPS-to LHC transfer lines will undergo important modifications. The changes to these collimators will allow them to cope with beam brightness and intensity levels much increased with respect to their original design parameters: nominal and ultimate LHC. The necessity for replacement of the current materials will need to be confirmed by a test in the High Radiation to Materials (HRM) facility at CERN. This test will involve low Z materials (such as Graphite and 3-D Carbon/Carbon composite), and will recreate the worst case scenario those materials could see when directly impacted by High luminosity LHC (HL-LHC) or Batch Compression Merging and Splitting (BCMS) beams. Thermo-structural simulations used for the material studies and research, the experiment preparation phase, the experiment itself, pre irradiation analysis (including ultrasound and metrology tests on the target materials), the results and their correlation with numerical simulations will be presented.

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TUPMR004

Simulations of High Current NuMI Magnetic Horn Striplines at FNAL

simulation, proton, target, focusing

1230

T. Sipahi, S. Biedron, S.V. Milton
CSU, Fort Collins, Colorado, USA
J. Hylen, R.M. Zwaska
Fermilab, Batavia, Illinois, USA

Both the NuMI (Neutrinos and the Main Injector) beam line, that has been providing intense neutrino beams for several Fermilab experiments (MINOS, MINERVA, NOVA), and the newly proposed LBNF (Long Baseline Neutrino Facility) beam line which plans to produce the highest power neutrino beam in the world for DUNE (the Deep Underground Neutrino Experiment) need pulsed magnetic horns to focus the mesons which decay to produce the neutrinos. The high-current horn and stripline design has been evolving as NuMI reconfigures for higher beam power and to meet the needs of the LBNF design. The CSU particle accelerator group has aided the neutrino physics experiments at Fermilab by producing EM simulations of magnetic horns and the required high-current striplines. In this paper, we present calculations, using the Poisson and ANSYS Maxwell 3D codes, of the EM interaction of the stripline plates of the NuMI horns at critical stress points. In addition, we give the electrical simulation results using the ANSYS Electric code. These results are being used to support the development of evolving horn stripline designs to handle increased electrical current and higher beam power for NuMI upgrades and for LBNF

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TUPMR005

First Results of a Turbo Generator Test for Powering the HV-Solenoids at a Relativistic Electron Cooler

electron, solenoid, high-voltage, power-supply

1233

A. Hofmann, K. Aulenbacher, M.W. Bruker, J. Dietrich, T. Weilbach
HIM, Mainz, Germany
W. Klag
IKP, Mainz, Germany
V.V. Parkhomchuk, V.B. Reva
BINP SB RAS, Novosibirsk, Russia

One of the challenges in a relativistic electron cooler is the generation of high voltage exceeding 2 MV and the powering of HV-solenoids, which need a floating power supply. As replacement of the well established, but limited, methods we propose streaming gas for the power transfer. The conversion of the energy by a turbo generator enables using scalable power supply / HV-generator combinations. BINP SB RAS has proposed two possibilities to build the power supply in a modular way. In the first proposal, two cascade transformers per module should be used; the first one powers 22 small HV-solenoids, the second one generates the voltage. In order to reach the final voltage, the modules are cascaded. The cascade transformers are fed by a turbo generator, which is driven by pressurised gas. The second possibility is to use two big HV-solenoids, which are powered directly by a turbo generator. The voltage could be generated for example with a Cockcroft Walton generator. A potential candidate is the Green Energy Turbine (GET) from the company DEPRAG, Germany. At the Helmholtz-Institut Mainz, two GET were tested. In this report, we present our experience and show first results.

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TUPMR023

First Operational Experience of HIE-Isolde

detector, dipole, ion, target

1284

J.A. Rodriguez, N. Bidault, E. Bravin, R. Catherall, E. Fadakis, P. Fernier, M.A. Fraser, M.J. Garcia Borge, K. Hanke, K. Johnston, Y. Kadi, M. Kowalska, M.L. Lozano Benito, E. Matli, S. Sadovich, E. Siesling, W. Venturini Delsolaro, F.J.C. Wenander
CERN, Geneva, Switzerland
M. Huyse, P. Van Duppen
KU Leuven, Leuven, Belgium
J. Pakarinen
JYFL, Jyväskylä, Finland
E. Rapisarda
PSI, Villigen PSI, Switzerland
M. Zielinska
Warsaw University, Warsaw, Poland

The High Intensity and Energy ISOLDE project (HIE-ISOLDE)* is a major upgrade of the ISOLDE facility at CERN. The energy range of the post-accelerator will be extended from 2.85 MeV/u to 9.3 MeV/u for beams with A/q = 4.5 (and to 14.3 MeV/u for A/q = 2.5) once all the cryomodules of the superconducting accelerator are in place. The project has been divided into different phases, the first of which (phase 1a) finished in October 2015 after the hardware and beam commissioning were completed**. The physics campaign followed with the delivery of both radioactive and stable beams to two different experimental stations. The characteristics of the beams (energies, intensities, time structure and beam contaminants) and the plans for the next experimental campaign will be discussed in this paper.
* The HIE-ISOLDE Project, Journal of Physics: Conference Series 312.
** HIE-ISOLDE First Commissioning Experience, IPAC'16
** Beam Commissioning of the HIE-ISOLDE Post-Accelerator, IPAC'16

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TUPMR024

Commissioning and First Accelerated Beams in the Reaccelerator (Rea3) of the National Superconducting Cyclotron Laboratory, MSU

ion, rfq, acceleration, cyclotron

1287

A.C.C. Villari, G. Bollen, M. Ikegami, S.M. Lidia, R. Shane, Q. Zhao
FRIB, East Lansing, Michigan, USA
D.M. Alt, D.B. Crisp, S.W. Krause, A. Lapierre, D.J. Morrissey, S. Nash, R. Rencsok, R.J. Ringle, S. Schwarz, C. Sumithrarachchi, S.J. Williams
NSCL, East Lansing, Michigan, USA

The ReAccelerator ReA3 is a worldwide unique, state-of-the-art reaccelerator for rare isotope beams. Beams of rare isotopes are produced and separated in-flight at the NSCL Coupled Cyclotron Facility and subsequently stopped in a gas cell. The rare isotopes are then continuously extracted as 1+ (or 2+) ions and transported into a beam cooler and buncher, followed by a charge breeder based on an Electron Beam Ion Trap (EBIT). In the charge breeder, the ions are ionized to a charge state suitable for acceleration in the superconducting radiofrequency (SRF) linac, extracted in a pulsed mode and mass analyzed. The extracted beam is bunched to 80.5 MHz and then accelerated to energies ranging from 300 keV/u up to 6 MeV/u, depending on their charge-to-mass ratio. Alternatively, stable isotope ions can be accelerated injecting stable gas in the EBIT. ReA3 was commissioned recently with stable 40Ar and 39K as well as with the rare isotope beams of 46Ar and 46K. This contribution will focus on the properties and techniques used to accelerate and transport rare isotope beams and will show results obtained during the preparation of the two first experiments using the ReA facility.

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TUPMR027

CERN's Fixed Target Primary Ion Programme

ion, extraction, target, proton

1297

D. Manglunki, M.E. Angoletta, J. Axensalva, G. Bellodi, A. Blas, M.A. Bodendorfer, T. Bohl, S. Cettour-Cave, K. Cornelis, H. Damerau, I. Efthymiopoulos, A. Fabich, J.A. Ferreira Somoza, A. Findlay, P. Freyermuth, S.S. Gilardoni, S. Hancock, E.B. Holzer, S. Jensen, V. Kain, D. Küchler, A.M. Lombardi, A.I. Michet, M. O'Neil, S. Pasinelli, R. Scrivens, R. Steerenberg, G. Tranquille
CERN, Geneva, Switzerland

The renewed availability of heavy ions at CERN for the needs of the LHC programme has triggered the interest of the fixed-target community. The project, which involves sending several species of primary ions at various energies to the North Area of the Super Proton Synchrotron, has now entered its operational phase. The first argon run, with momenta ranging from 13 AGeV/c to 150 AGeV/c, took place from February 2015 to April 2015. This paper presents the status of the project, the performance achieved thus far and an outlook on future plans.

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TUPMR028

Spin Correlations Study for the New g-2 Experiment at Fermilab

storage-ring, simulation, injection, quadrupole

1301

D. Stratakis, J.D. Crnkovic, W. Morse, V. Tishchenko
BNL, Upton, Long Island, New York, USA

The muon g-2 experiment executed at Brookhaven concluded in 2001 and measured a discrepancy of more than three standard deviations compared to the Standard Model (SM) calculation. A new initiative at Fermilab is under construction to improve the experimental accuracy four-fold. Achieving this goal, however, requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we examine systematic errors that can arise from correlations between muon spin and transverse coordinates for the new g-2 experiment. To achieve this goal we perform end-to-end spin tracking simulations from the production target up to the ring injection point and compare our findings against the results from the Brookhaven experiment. We detail similarities and differences.

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TUPMR042

Transverse Profile Expansion and Homogenization for the Beamline of XIPAF

target, proton, optics, simulation

1346

Z. Yang, C.T. Du, X. Guan, W. Wang, X.W. Wang, H.J. Yao, S.X. Zheng
TUB, Beijing, People's Republic of China

For the Xi'an 200 MeV Proton Application Facility (XiPAF), one important thing is to produce more homog-enous beam profile at the target to fulfill the requirements of the beam application. Here the beam line is designed to meet the requirement of beam expansion and homogenization, and the step-like field magnets are employed for the beam spot homogenization. The simulations results including space charge effects and errors show that the beam line can meet the requirements well at the different energies (from 10 MeV to 230 MeV) and different beam spot size (from 20mm to 200mm).

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TUPMR052

Commissioning Preparation of the AWAKE Proton Beam Line

proton, laser, plasma, extraction

1374

J.S. Schmidt, B. Biskup, C. Bracco, B. Goddard, R. Gorbonosov, M. Gourber-Pace, E. Gschwendtner, L.K. Jensen, O.R. Jones, V. Kain, S. Mazzoni, M. Meddahi
CERN, Geneva, Switzerland

The AWAKE experiment at CERN will use a proton bunch with an momentum of 400 GeV/c from the SPS to drive large amplitude wakefields in a plasma. This will require a ~830 m long transfer line from the SPS to the experiment. The prepa- rations for the beam commissioning of the AWAKE proton transfer line are presented in this paper. They include the detailed planning of the commissioning steps, controls and beam instrumentation specifications as well as operational tools, which are developed for the steering and monitoring of the beam line. The installation of the transfer line has been finished and first beam is planned in summer 2016.

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TUPMW007

Impact of Long Range Beam-Beam Effects on Intensity and Luminosity Lifetimes from the 2015 LHC Run

luminosity, emittance, hadron, dynamic-aperture

1422

M.P. Crouch, R.B. Appleby
UMAN, Manchester, United Kingdom
D. Banfi, C. Tambasco
EPFL, Lausanne, Switzerland
J. Barranco, R. Bruce, X. Buffat, T. Pieloni, M. Pojer, B. Salvachua, G. Trad
CERN, Geneva, Switzerland
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: Research supported by the High Luminosity LHC project
Luminosity is one of the key parameters that determines the performance of colliding beams in the Large Hadron Collider (LHC). Luminosity can therefore be used to quantify the impact of beam-beam interactions on the beam lifetimes and emittances. The High Luminosity Large Hadron Collider (HL-LHC) project aims to reach higher luminosities, approximately a factor of 7 larger than the nominal LHC at peak luminosity without crab cavities. Higher luminosities are achieved by increasing the bunch populations and reducing the transverse beam sizes. This results in stronger beam-beam effects. Here the LHC luminosity and beam intensity decay rates are analysed as a function of reducing beam separation with the aim of characterising the impact of beam-beam effects on the luminosity and beam lifetime. The analysis and results are discussed with possible application to the HL-LHC upgrade.

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TUPMW012

Beam Offset Stabilization Techniques for the LHC Collision Points

luminosity, optics, ground-motion, operation

1438

A.A. Gorzawski, R. Jacobsson, J. Wenninger
CERN, Geneva, Switzerland

Maintaining head-on collisions over many hours is an important aspect of optimizing the performance of a collider. For current LHC operation where the beam optics is fixed during periods of colliding beam, mainly ground motion induced perturbations have to be compensated. The situation will become significantly more complex when luminosity leveling will be applied following the LHC luminosity upgrades. During β^* leveling the optics in the interaction region changes significantly, feed-downs from quadrupole misalignment may induce significant orbit changes that may lead to beam offsets at the collision points. Such beam offsets induce a loss of luminosity and reduce the stability margins for collective effects that is provided by head-on beam-beam. It is therefore essential that the beam offsets at the collision points are minimized during the leveling process. This paper will review sources and mitigation techniques for the orbit perturbation at the collision points during β^* leveling, and present results of experiments performed at the LHC to mitigate and compensate such offsets.

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TUPMW013

Experimental Demonstration of β* Leveling at the LHC

luminosity, betatron, controls, emittance

1442

A.A. Gorzawski, D. Mirarchi, B. Salvachua, J. Wenninger
CERN, Geneva, Switzerland

The HL-LHC project foresees to boost the LHC peak luminosity beyond the capabilities of the LHC experimental detectors. Leveling the luminosity down to a constant value that is sustainable for the experiments is therefore the operational baseline of HL-LHC. Various luminosity leveling techniques are available at the LHC. Leveling by adjusting β^*, the betatron function at the interaction point, to maintain a constant luminosity is favorable because the beams remain head-on which provides optimal stability from the point of view of collective effects. Smooth leveling by β^* requires however excellent control of the beam orbits and beam losses in the interaction regions since the beam offsets should not vary by more than around one r.m.s. beam size during the process. This leveling scheme has been successfully tested and experimentally demonstrated during the LHC machine development program in 2015. This paper presents results on luminosity leveling over a β^* range from 10 m to 0.8 m and provides an outlook on future developments and use of this technique at the LHC.

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TUPMW027

The 2015 Heavy-Ion Run of the LHC

luminosity, ion, heavy-ion, operation

1493

J.M. Jowett, R. Alemany-Fernandez, R. Bruce, M. Giovannozzi, P.D. Hermes, W. Höfle, M. Lamont, T. Mertens, S. Redaelli, M. Schaumann, J.A. Uythoven, J. Wenninger
CERN, Geneva, Switzerland

In late 2015 the LHC collided lead nuclei at a beam energy of 6.37 Z TeV, chosen to match the 5.02 TeV per colliding nucleon pair of the p-Pb collision run in 2013. In so doing, it surpassed its design luminosity by a factor of 2. Besides the higher energy, the operational configuration had a number of new features with respect to the previous Pb-Pb run at 3.5 Z TeV in 2011; unusual bunch patterns providing collisions in the LHCb experiment for the first time, luminosity levelling and sharing requirements, a vertical displacement of the interaction point in the ALICE experiment, and operation closer to magnet quench limits with mitigation measures. We present a summary of the commissioning and operation and what has been learned in view of future heavy-ion operation at higher luminosity.

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TUPMW028

Bound-Free Pair Production in LHC Pb-Pb Operation at 6.37 Z TeV per Beam

luminosity, ion, dipole, simulation

1497

J.M. Jowett, B. Auchmann, C. Bahamonde Castro, M.K. Kalliokoski, A. Lechner, T. Mertens, M. Schaumann, C. Xu
CERN, Geneva, Switzerland

In the 2015 Pb-Pb collision run of the LHC, the power of the secondary beams emitted from the interaction point by the bound-free pair production process reached new levels while the propensity of the bending magnets to quench is higher at the new magnetic field levels. This beam power is about 70 times greater than that contained in the luminosity debris and is focussed on a specific location. As long foreseen, orbit bumps were introduced in the dispersion suppressors around the highest luminosity experiments to mitigate the risk by displacing and spreading out these losses. An experiment designed to induce quenches and determine the quench levels and luminosity limit was carried out to assess the need for special collimators to intercept these secondary beams.

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TUPMY004

The MICE Demonstration of Muon Ionization Cooling

emittance, lattice, betatron, simulation

1547

J.-B. Lagrange, C. Hunt, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
V.C. Palladino
INFN-Napoli, Napoli, Italy
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

Funding: STFC, DOE, NSF, INFN, CHIPP AND MORE
Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams necessary to elucidate the physics of flavour at the Neutrino Factory and to provide lepton-antilepton collisions up to several TeV at the Muon Collider. The international Muon Ionization Cooling Experiment (MICE) will demonstrate muon ionization cooling, the technique proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam traverses a material (the absorber) loosing energy, which is replaced using RF cavities. The combined effect is to reduce the transverse emittance of the beam (transverse cooling). The configuration of MICE required to deliver the demonstration of ionization cooling is being prepared in parallel to the execution of a programme designed to measure the cooling properties of liquid-hydrogen and lithium hydride. The design of the cooling-demonstration experiment will be presented together with a summary of the performance of each of its components and the cooling performance of the experiment.
Submitted by the MICE speakers bureau that will identify later a member of the collaboration to present the contribution

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TUPMY008

Phase Rotation of Muon Beams for Producing Intense Low-energy Muon Beams

proton, simulation, target, solenoid

1556

Y. Bao, Y. Bao, G. Hansen
UCR, Riverside, California, USA
D.V. Neuffer
Fermilab, Batavia, Illinois, USA

Low-energy muon beams are useful for rare decay researches, providing access to new physics that cannot be addressed at high-energy colliders. However, the large initial energy spread of the muon beam greatly limits the efficiency of muon applications. In this paper we outline a phase rotation method to significantly increase the intensity of low-energy muons. The muons are first produced by a short pulsed proton driver, and after a drift channel they form a time-momentum correlation. A series of rf cavities is used to bunch the muons and then phase rotate the bunches so that all the bunches reaches a momentum around 100 MeV/c. Then another group of rf cavities is used to decelerate the muon bunches to low-energy. Such a method produces low-energy muons with an efficiency of 0.1 muon per 8 GeV proton, which is significantly higher than the current Mu2e experiment at Fermilab, and it provides the possibility for the next generation rare decay researches.

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TUPMY010

Status of Mice Step IV

emittance, factory, optics, scattering

1562

P.M. Hanlet
IIT, Chicago, Illinois, USA

Funding: STFC, DOE, NSF, INFN, CHIPP AND MORE
Muon beams of low emittance provide the basis for the intense, well characterised neutrino beams of the Neutrino Factory and for lepton-antilepton collisions at energies of up to several TeV at a Muon Collider. The international Muon Ionization Cooling Experiment (MICE) will demonstrate ionization cooling–the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam. MICE is being constructed in a series of Steps. The configuration currently in operation at the Rutherford Appleton Laboratory is optimised for the study the properties of liquid hydrogen and lithium hydride that affect cooling. The plans for data taking in the present configuration will be described together with a summary of the status of preparation of the experimental configuration by which MICE will demonstration the principle of ionization cooling.
Submitted by the MICE speakers bureau that will identify later a member of the collaboration to present the contribution

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TUPMY012

Hybrid Methods for Simulation of Muon Ionization Cooling Channels

simulation, emittance, scattering, lattice

1568

J.D. Kunz
IIT, Chicago, Illinois, USA
M. Berz, K. Makino
MSU, East Lansing, Michigan, USA
P. Snopok
Illinois Institute of Technology, Chicago, Illlinois, USA

Funding: Work is supported by the U.S. Department of Energy.
COSY Infinity is an arbitrary-order beam dynamics simulation and analysis code. It can determine high-order transfer maps of combinations of particle optical elements of arbitrary field configurations. New features are being developed for inclusion in COSY to follow the distribution of charged particles through matter. To study in detail some of the properties of muons passing through material, the transfer map approach alone is not sufficient. The interplay of beam optics and atomic processes must be studied by a hybrid transfer map–Monte Carlo approach in which transfer map methods describe the deterministic behavior of the particles in the accelerator channel, and Monte Carlo methods are used to model the stochastic processes intrinsic to liquid and solid absorbers. The advantage of the new approach is that the vast majority of the dynamics is represented by fast application of the high-order transfer map of an entire element and accumulated stochastic effects. The gains in speed are expected to simplify the optimization of muon cooling channels which are usually very computationally demanding. Progress on the development of the required algorithms is reported.

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TUPMY030

Measurements of Transmitted Electron Beam Extinction through Si Crystal Membranes

electron, emittance, scattering, laser

1611

E.A. Nanni, R.K. Li, C. Limborg, X. Shen, S.P. Weathersby
SLAC, Menlo Park, California, USA
W.S. Graves, R. Kirian, J. Spence, U. Weierstall
Arizona State University, Tempe, USA

A recently proposed method for the generation of relativistic electron beams with nanometer-scale current modulation requires diffracting relativistic electrons from a perfect crystal Si grating, accelerating the diffracted beam and imaging the crystal structure into the temporal dimension via emittance exchange. The relative intensity of the current modulation is limited by the ability to extinguish the transmitted beam via diffraction with a single-crystal Si membrane. In these preliminary experiments we will measure the extinction of the transmitted electron beam at zero scattering angle due to multiple Bragg scattering from a Si membrane with a uniform thickness of 340 nm at 2.35 MeV using the SLAC UED facility. The impact of beam divergence and charge density at the Si target will be quantified. The longevity of the Si membrane will also be investigated by monitoring the diffraction pattern as a function of time to observe the potential onset of damage to the crystal.

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TUPMY038

Preliminary Measurement of the Transfer Matrix of a TESLA-type Cavity at FAST

cavity, simulation, HOM, focusing

1632

A. Halavanau, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
N. Eddy, D.R. Edstrom, A. Lunin, P. Piot, J. Ruan, J.K. Santucci, J.K. Santucci, N. Solyak
Fermilab, Batavia, Illinois, USA

Funding: US Department of Energy (DOE) under contract DE-SC0011831 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359.
Superconducting linacs are capable of producing intense, ultra-stable, high-quality electron beams that have widespread application in Science and Industry. Many current and planned projects employ 1.3-GHz 9-cell superconducting cavities of the TESLA design*. In the present paper we discuss the transverse-focusing properties of such a cavity and non-ideal transverse-map effects introduced by field asymmetries in the vicinity of the input and high-order-mode radiofrequency (RF) couplers**. We especially consider the case of a cavity located downstream of an RF-gun in a setup similar to the photoinjector of the Fermilab Accelerator Science and Technology (FAST) facility. Preliminary experimental measurements of the CC2 cavity transverse matrix were carried out at the FAST facility. The results are discussed and compared with analytical and numerical simulations.
* A. Aunes et al., Phys. Rev.ST Accel. Beams 3, 092001 (2000).
** P. Piot, el. al., Proc. 2005 Part. Accel. Conf., Knoxville, TN, p. 4135 (2005).

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TUPOR025

Beam Break-up Measurements at the Recirculating Electron Accelerator S-DALINAC

linac, recirculation, HOM, cavity

1714

T. Kürzeder, M. Arnold, L.E. Jürgensen, J. Pforr, N. Pietralla
TU Darmstadt, Darmstadt, Germany
F. Hug
IKP, Mainz, Germany

Funding: Supported by the German Federal Ministry for Education and Research (BMBF) under Grant No. 05K13RDA
Beam break-up (BBU) instability is an important limitation to the current which can be accelerated in a superconducting linac. In particular recirculating machines and Energy Recovery Linacs have to deal with that problem. Therefore, it is important to find strategies for increasing the threshold currents of these machines. The superconducting accelerator S-DALINAC at the Technische Universität Darmstadt provides electron beams in c.w. for nuclear physics experiments since 1991. It consists of a 10 MeV injector and a 40 MeV main linac where two and eight 20-cell elliptical 3-GHz cavities are operated in a liquid helium bath at 2 K. Using two recirculation beam lines the main accelerator can be used up to 3 times. Operational experiences have shown that the design-beam current of 20 μA could not be reached. One reason is the occurrence of BBU. We will report on measurements of the threshold current at various energy settings of the S-DALINAC. The results of a first test to increase the BBU limit by using skew quadrupole magnets in the first recirculation beam line will be presented.

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TUPOR031

Trapped Ion Effects and Mitigation During High Current Operation in the Cornell DC Photoinjector

ion, radiation, linac, vacuum

1735

S.J. Full, A.C. Bartnik, I.V. Bazarov, J. Dobbins, B.M. Dunham, G.H. Hoffstaetter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: U.S. Department of Energy (Grant No. DE-SC0012493), National Science Foundation (Award No. NSF-DMR 0807731)
The Cornell high intensity photoinjector reaches a new regime of linac beam parameters where high continuous-wave electron beam currents lead to ion trapping. Above 10 mA, we have observed beam trips that limit stable machine operation to approximately 10^-15 minutes. By applying known ion clearing methods, the machine lifetime increases to at least 24 hours of continuous operation, suggesting that trapped ions are the most likely cause of the trips. In this paper we share some of our observations ion trapping in the photoinjector, as well as experimental tests of three common ion mitigation methods: clearing electrodes, beam shaking and bunch gaps.

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TUPOW002

Current Status of the Milliampere Booster for the Mainz Energy-recovering Superconducting Accelerator

electron, simulation, linac, gun

1741

R.G. Heine, K. Aulenbacher, L.M. Hein, C. Matejcek
IKP, Mainz, Germany

Funding: Work supported by German Science Foundation (DFG) under the Cluster of Excellence "PRISMA" EXC1098/2014
The Milliampere Booster (MAMBO) is the injector linac for the Mainz Energy-recovering Superconducting Accelerator MESA. The MESA facility is currently under design at the Institut für Kernphysik (KPH) at Johannes Gutenberg University of Mainz (JGU). In this paper we will present the current design status of the linac.

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TUPOW015

Experiment of High Resolution Field Emission Imaging in an rf Photocathode Gun

cathode, electron, gun, background

1772

J.H. Shao, H.B. Chen, J. Shi, X.W. Wu
TUB, Beijing, People's Republic of China
S.P. Antipov, S.V. Baryshev, C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
M.E. Conde, W. Gai, G. Ha, E.E. Wisniewski
ANL, Argonne, Illinois, USA
F.Y. Wang
SLAC, Menlo Park, California, USA

The first in situ high resolution field emission (FE) imaging experiment has been carried out on an L-band photocathode gun test stand at Argonne Wakefield Accelerator facility (AWA). Separated strong emitters have been observed to dominate the field emission. Field enhancement factor, beta, of small regions on the cathode has been measured with the imaging system. It is shown that most strong emitters overlaps with the high beta regions. The post surface examinations reveal the origins of ~75% strong emitters overlap with the spots where rf breakdown have occurred. Detailed results are presented in this paper.

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TUPOW018

Tunable High-Intensity Electron Bunch Train Production Based on Nonlinear Longitudinal Space Charge Oscillation

radiation, electron, space-charge, gun

1782

Z. Zhang, H.B. Chen, Y.-C. Du, W.-H. Huang, J. Shi, X.L. Su, C.-X. Tang, Q.L. Tian, D. Wang, W. Wang, L.X. Yan, L.M. Zheng, Z. Zhou
TUB, Beijing, People's Republic of China
W. Gai
ANL, Argonne, Illinois, USA

High peak current electron bunch trains with tunable terahertz (THz) spacing are produced and measured experimentally. An initial picosecond periodic modulation in the temporal profile of a relativistic electron beam is magnified by the longitudinal space charge forces. As opposed to trying to reduce its smearing effect for large beam current, we take advantages of the nonlinear space charge oscillation through controlling the plasma phase advance. The spacing of the bunch train can be varied continuously either by tuning the velocity bunching of a radio-frequency gun or by tuning the compression of a downstream magnetic chicane. The narrow-band μJ-level THz radiation from the bunch train are also measured with tunable central frequency of the spectral from ~0.5 THz to 1.6 THz. The bunch train measurements are consistent with the particle tracking simulations.

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TUPOW047

Generation of a Coherent Cherenkov Radiation by using Electron Bunch Tilting

radiation, electron, target, gun

1870

K. Sakaue
Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan
R. Kuroda, Y. Taira
AIST, Tsukuba, Ibaraki, Japan
M. Nishida, M. Washio
Waseda University, Tokyo, Japan
J. Urakawa
KEK, Ibaraki, Japan

We have been developing a compact accelerator based a laser photocathode rf electron gun at Waseda University. Low emittance and short bunched electron beam can be generated from the gun. Also, the rf transverse deflecting cavity was developed for the bunch length measurement. We performed an experiment for generating a coherent Cherenkov radiation using bunch tilting. The rf transverse deflector can give a tilt for the electron bunch, and the tilt angle was set to the Cherenkov radiating angle which determined by the target refractive index. We successfully demonstrated a coherent Cherenkov radiation and the characterization of the radiation. The principle of coherent Cherenkov radiation generation, the experimental results and future prospective will be presented at the conference.

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TUPOW053

Measurement of Terahertz Generation in a Metallic, Corrugated Beam Pipe

radiation, electron, dipole, laser

1889

K.L.F. Bane
SLAC, Menlo Park, California, USA
S.P. Antipov
ANL, Argonne, Illinois, USA
M.G. Fedurin, K. Kusche, C. Swinson
BNL, Upton, Long Island, New York, USA
D. Xiang
Shanghai Jiao Tong University, Shanghai, People's Republic of China

Funding: Work supported by the Department of Energy, Office of Science, Office of Basic Energy Science, under Contract No. DE-AC02-76SF00515
A method for producing narrow-band THz radiation proposes passing an ultra-relativistic beam through a metallic pipe with small periodic corrugations*. We present results of a measurement of such an arrangement at BNL's Advanced Test Facility (ATF). Our pipe was copper and was 5 cm long; the aperture was cylindrically symmetric, with a 1 mm (radius) bore and a corrugation depth (peak-to-peak) of 60 um. In the experiment we measured both the effect on the beam of the structure wakefield and the spectral properties of the radiation excited by the beam. We began by injecting a relatively long beam–-compared to the wavelength of the radiation–-to excite the structure, and then used a downstream spectrometer to infer the radiation wavelength. This was followed by injecting a shorter bunch, and then using an interferometer (also downstream of the corrugated pipe) to measure the spectrum of the induced THz radiation. Our experimental set-up was simple and not optimized for the efficient collection of the radiation by e.g. the use of tapered horns. As such it can be considered a proof-of-principle experiment.
* K. Bane and G. Stupakov, NIM A677 (2012) 67-73.

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TUPOW054

Characterization of a Sub-THz Radiation Source Based on a 3 MeV Electron Beam and Future Plans

electron, radiation, quadrupole, laser

1892

A.V. Smirnov, R.B. Agustsson, T.J. Campese, Y.C. Chen, J.J. Hartzell, B.T. Jacobson, A.Y. Murokh, M. Ruelas
RadiaBeam, Santa Monica, California, USA
W. Berg, J.C. Dooling, L. Erwin, R.R. Lindberg, S.J. Pasky, N. Sereno, Y.-E. Sun, A. Zholents
ANL, Argonne, Ilinois, USA
Y. Kim
KAERI, Jeongeup-si, Republic of Korea

Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC-FOA-0007702)
Design features and some past experimental results are presented for a sub-THz wave source employing the Advanced Photon Source's RF thermionic electron gun. The setup includes a compact alpha-magnet, four quadrupoles, a novel radiator, a THz transport line, and THz diagnostics. The radiator is composed of a dielectric-free, planar, over-sized structure with gratings. The gratings are integrated into a combined horn antenna and ~90° permanent bending magnet. The magnetic lattice enables operation in different modes, including conversion to a flat beam for efficient interaction with the radiating structure. The experiment described demonstrated the generation of narrow bandwidth THz radiation from a compact, laser and undulator-free, table-top system. This concept could be scaled to create a THz-sub-THz source capable of operating in long-pulse, multi-bunch, and CW modes. Additionally, the system can be used to remove unwanted time-dependent energy variations in longitudinally compressed electron bunches or for various time-dependent beam diagnostics. Plans for future experiments and upgrades are also discussed.

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TUPOY006

Improvement of Scanning Irradiation in Gunma University Heavy Ion Medical Center

extraction, ion, heavy-ion, acceleration

1914

H. Souda, T. Kanai, K. Kikuchi, Y. Kubota, A. Matsumura, H. Shimada, M. Tashiro, K. Torikai, M. Torikoshi, S. Yamada, K. Yusa
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
T. Fujimoto
AEC, Chiba, Japan
E. Takeshita
Kanagawa Cancer Center, Ion-beam Radiation Oncology Center in Kanagawa, Kanagawa, Japan

Funding: Work collaborated with Mitsubishi Electric Corporation Ltd. Work supported by JSPS Kakenhi 26860395, Program for Cultivating Global Leaders in Heavy Ion Therapeutics and Engineering by MEXT of Japan.
Gunma University Heavy Ion Medical Center (GHMC) is a compact heavy ion treatment facility* and have experienced 5 years of successful treatment operation. GHMC has 3 treatment room using broad beam (wobbling) irradiation system and 1 experimental irradiation room for the research and development of a spot-scanning irradiation. During the study toward the treatment, several improvements were done in both accelerator and irradiation system. For accelerators, slow extraction from a synchrotron using a transverse rf field is tested**. Compared with conventional extraction system of rf acceleration, ripples of the beam spill (peak to bottom ratio) is reduced from almost 100% to 60%; the deviation of the beam center position and the deviation of the beam size (1σ) are reduced to the order of 0.1 mm. For irradiation system, regularly operation for biological experiments has started form June 2014. In order to shorten the experiment time, 2-dimensional optimization of the irradiation planning was carried out. After the optimization, the irradiation time was reduced by 30% with keeping the dose uniformity within ±2.5%.
* T. Ohno et al., Cancers, 3, 4046 (2011)
** K. Noda et al., Nucl. Instrum. Meth. A492, 253 (2002)

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TUPOY019

Geant4 Simulations of Proton-induced Spallation for Applications in ADSR Systems

neutron, proton, target, simulation

1943

S.C. Lee
IIAA, Huddersfield, United Kingdom
C. Bungau, R. Cywinski
University of Huddersfield, Huddersfield, United Kingdom

Neutron spallation is an efficient process for producing intense neutron fluxes that can be exploited in Accelerator Driven Subcritical Reactors (ADSRs) for energy production and the transmutation of nuclear waste. In order to assess the feasibility of spallation driven fission and transmutation we have simulated proton induced neutron production using GEANT4, initially benchmarking our simulations against published experimental neutron spectra produced from a thick lead target bombarded with 0.5 and 1.5 GeV protons. The Bertini and INCL models available in GEANT4, coupled with the high precision (HP) neutron model, are found to adequately reproduce the published experimental data. Given the confidence in the GEANT4 simulations provided by this benchmarking we have then proceeded to simulate neutron production as a function of target geometry and thence to some preliminary studies of neutron production in an ADSR with a geometry similar to that of the proposed Belgian MYRRHA project. This paper presents the results of our GEANT4 benchmarking and simulations.

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TUPOY047

Development of a Non-destructive Inspection System for Industrial and Societal Infrastructures with 950 keV/3.95 MeV Portable X-band Linac-based X-ray

linac, site, radiation, distributed

2011

R. Yano
The University of Tokyo, Tokyo, Japan
J. Kusano
Accuthera Inc., Kawasaki, Kanagawa, Japan
M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan

Advanced maintenance for aging industrial and societal infrastructures such as chemical plant and bridge are strongly needed recently. For the purpose, we are developing, applying and upgrading the 950 keV/3.95 MeV X-band linac X-ray sources for the on-site inspection. Less than 1 MeV accelerators are available for on-site inspection and less than 3.95 MeV accelerators are allowable for only bridge on-site inspection. These systems can visualize in seconds inner states of infrastructures, such as crack of concrete, iron-reinforced rod/wire and other imperfections. By using the 950 keV system, we conducted the first inspection of the real bridge and evaluated degradation of pre-stressed concrete wires. We also demonstrated first on-site use of the 3.95 MeV system in Japan in 2015. We are also performing structural analysis to evaluate the degradation of strength. For more precise evaluation, we are going to carry out a partial angle CT to reconstruct a two-dimensional inner structure. We are going to present the results and strategy of degradation evaluation of the industrial and societal infrastructures by the 950 keV / 3.95 MeV X-ray sources.

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TUPOY053

In-Kind Contributions: A Prosperous Model of Procurement for Large-scale Science Projects

interface, controls, vacuum, site

2017

R. Amirikas, P. Ghosh
FAIR, Darmstadt, Germany

The number of research infrastructures which are being built with significant amount of In-Kind Contributions (IKCs) from partners and stakeholders is on the increase. One of the main advantages of the utilization of IKCs in big science projects is to enable numerous partners with technological and scientific know-how participate directly in such projects. Thus, IKCs promote capacity building in technology and knowledge transfer of these partners. However, management and execution of IKCs are particularly challenging. The 2nd In-Kind Contributions Workshop (IKCW 2015) was organized by the Facility for Antiproton and Ion Research in Europe (FAIR) with the aim of sharing experiences on the procurement and management of large-scale international science projects through IKCs. This paper focuses on the analysis of the issues pertaining to how to best implement and execute IKCs from the initial phase of assignment until full delivery for both accelerator and experiments. Discussions held during IKCW 2015 are used to highlight these points further. The goal of this paper is to present the reader with a synopsis of the challenges and opportunities faced in procurement through IKCs.

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TUPOY055

Study on Electro-polishing of Nb Surface by Periodic Reverse Current Method with Sodium Hydroxide Solution

cavity, operation, SRF, cathode

2020

J. Taguchi, A. Namekawa
Nomura Plating Co, Ltd., Osaka, Japan
H. Hayano, T. Saeki
KEK, Ibaraki, Japan
C.E. Reece, H. Tian
JLab, Newport News, Virginia, USA

Electropolishing is one of the best methods of Nb surface finishing of the superconducting cavity to obtain high accelerating gradient. Mixed solution of hydrofluoric acid and sulfuric acid is generally used in the electropolishing of Nb. But this solution is very dangerous and because the corrosion of the metal occurs by hydrofluoric acid, all equipment must be made of high density polyethylene or fluorocarbon resin. This causes the expensive cost of electropolishing instrument. In addition, this solution produces sulfur compound on the Nb surface in the electropolishing reaction. This sulfur compound can be field emission sources on the inner surface of cavity and degrades acceleration performance. In this poster, we report noble electropolishing method using periodic reverse current and sodium hydroxide solution. The reaction produces no sulfur content and the equipment is less expensive because the instrument can be made of usual plastic material. As the result of experiments with Nb-coupon samples, we found that the surface roughness is equivalent to the conventional electropolishing method.

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WEOAA03

Experimental Study on Optical Vortex from a Helical Undulator at UVSOR-III

undulator, radiation, synchrotron, synchrotron-radiation

2036

M. Hosaka
Nagoya University, Nagoya, Japan
M. Katoh, N.S. Mirian
UVSOR, Okazaki, Japan
T. Konomi, N. Yamamoto
KEK, Ibaraki, Japan
K. Kuroda
ISSP, Kashiwa-shi, Japan
K. Miyamoto, S. Sasaki
HSRC, Higashi-Hiroshima, Japan

A relativistic electron in helical undulator emits an optical vortex which carries orbital angular momentum. Sasaki and McNulty predicted theoretically that higher harmonics of helical undulator is optical vortex* and the experimental verification was made at BESSY** and UVSOR-III***. Further, we have made a systematic study to characterize the optical vortex from a helical undulator at UVSOR-III. Synchrotron radiation in UV region from an optical klystron undulator system consisting of two APPLE-II helical undulators and a buncher was used for the experiment. Patterns resulting from inferences between two undulator radiation carrying different angular momentums were clearly observed. To investigate the optical properties of the radiation, diffraction experiments were carried out. Specific diffraction patterns due to the phase singularity in the radiation center were clearly observed. The experimental results are compared with simulation.
* S. Sasaki, I. McNulty, Phys. Rev. Lett. 100, 124801 (2008)
** J. Bahrdt et al., Phys. Rev. Lett. 111, 034801 (2013)
*** e.g. S. Sasaki et al., presented in SRI2015 (2015)

Slides WEOAA03 [11.023 MB]

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WEOCA02

First Operational Experience with an Internal Halo Target at RHIC

target, operation, detector, collider

2070

C. Montag
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An internal halo target has been installed in the STAR detector at RHIC to extend the energy range towards lower energies and increase the event rates in the search for the critical point in the QCD phase diagram. We discuss geometric considerations that led to the present target layout and present first operational results.

Slides WEOCA02 [1.605 MB]

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WEOBB01

Single Micron Single-Bunch Turn-by-Turn BPM Resolution Achieved at NSLS-II

storage-ring, operation, collective-effects, Windows

2095

B. Podobedov, W.X. Cheng, K. Ha, Y. Hidaka, J. Mead, O. Singh, K. Vetter
BNL, Upton, Long Island, New York, USA

NSLS-II state-of-the-art BPMs provide a single micron turn-by-turn BPM resolution for any bunch train of reasonable intensity. For certain beam dynamics studies a similar, or even better, resolution is desired for a single-, or a few-bunch fill, which is not yet available with our standard BPM signal processing. This paper describes our experience with more advanced BPM ADC signal processing which allowed us to significantly improve turn-by-turn BPM resolution in single bunch mode down to the level of about one micron at ~1 nC/bunch. We also present the examples of machine studies that benefit from this BPM performance enhancement.

Slides WEOBB01 [2.565 MB]

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WEOBB02

Status of Wakefield Monitor Experiments at the CLIC Test Facility

detector, emittance, pick-up, electron

2099

R.L. Lillestøl, E. Adli, J. Pfingstner
University of Oslo, Oslo, Norway
N. Aftab, S. Javeed
PINSTECH, Islamabad, Pakistan
R. Corsini, S. Döbert, W. Farabolini, A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland

For the very low emittance beams in CLIC, it is vital to mitigate emittance growth which leads to reduced luminosity in the detectors. One factor that leads to emittance growth is transverse wakefields in the accelerating structures. In order to combat this the structures must be aligned with a precision of a few um. For achieving this tolerance, accelerating structures are equipped with wakefield monitors that measure higher-order dipole modes excited by the beam when offset from the structure axis. We report on such measurements, performed using prototype CLIC accelerating structures which are part of the module installed in the CLIC Test Facility 3 (CTF3) at CERN. Measurements with and without the drive beam that feeds rf power to the structures are compared. Improvements to the experimental setup are discussed, and finally remaining measurements that should be performed before the completion of the program are summarized.

Slides WEOBB02 [2.928 MB]

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WEOBB03

A Non-destructive Profile Monitor Using a Gas Sheet

electron, ion, proton, target

2102

N. Ogiwara, Y. Hikichi, J. Kamiya, M. Kinsho, Y. Namekawa
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
M. Fukuda, K. Hatanaka, T. Shima
RCNP, Osaka, Japan

We are developing a dense gas-sheet target to realize a non-destructive and fast-response beam profile monitor for 3 GeV rapid cycling synchrotron (RCS) in the J-PARC. This time, to demonstrate the function of the gas sheet for measuring the 2 dimensional profiles of the accelerated beams, the following experiments were carried out: 1) The gas sheet with a thickness of 1.5 mm and the density of 2×10^-4 Pa was generated by the combination of the deep slit and the thin slit. Here, the gas sheet was produced by the deep slit, and the shape of the sheet was improved by the thin slit. 2) For the electron beam of 30 keV with a diameter greater than 0.35 mm, the position and the two-dimensional profiles were well measured using the gas sheet. 3) Then the profiles of the 400 MeV proton beam with a current of 1×10-6 A was well measured, too.

Slides WEOBB03 [4.718 MB]

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WEPMB019

Magnetic Fields in Bulk, Film, and Multilayer Superconductors in Front of a Multi-turn Coil

photon

2164

T. Kubo
KEK, Ibaraki, Japan

Funding: JSPS Young Scientists(B) #26800157, JSPS Challenging Exploratory Research #26600142, MEXT Photon and Quantum Basic Research Coordinated Development Program
The magnetic field distribution formulae in a bulk superconductor, a superconducting film, and an SIS multilayer structure in front of a multi-turn coil are derived, which may be useful for a detailed analysis in a vortex field measurement by using the third harmonic method.
* See for example the invited oral presentation by T. Kubo, "Theory of multilayer coating for proof-of-concept experiments", at SRF2015
** C.Z.Antoine et al., Appl. Phys. Lett. 102, 102603 (2013)

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WEPMB021

Construction of Measurement System for Superconducting Characteristics on Thin-film Samples at KEK

cavity, solenoid, operation, SRF

2167

T. Saeki, H. Hayano, T. Kubo
KEK, Ibaraki, Japan
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
H. Oikawa
Utsunomiya University, Utsunomiya, Japan

We set up a measurement system for superconducting characteristics on thin-film samples at KEK. The system includes small-sized and middle-sized cryostats, where critical temperature, critical magnetic field, Residual Resistiviy Ratio (RRR), Superconducting RF (SRF) resistivity can be measured on thin-film samples. A small-sized cryostat has a compact refrigerator to cool down samples for the measurements of critical temperature and RRR. On the other had, we can cool down various setups with a middle-sized cryostat by using liquid helium. A thin-film sample is set into a mushroom cavity and the SRF characteristics of the thin-film sample can be measured. In another setup, a sample is set with a small coil and the third harmonic measurement is done on the sample around the critical temperature. Finally, a thin-film sample is set into the bore-center of superconducting magnet and the magnetization of sample is measured with external magnetic field around the critical temperature. This article presents the details of the system and some measurements of samples by the system.

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WEPMB029

Research of Nitrogen Doping at IHEP

niobium, cavity, vacuum, electron

2186

P. Sha
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
J.P. Dai
IHEP, Beijing, People's Republic of China
F. Jiao
PKU, Beijing, People's Republic of China

Funding: Work funded by National Natural Science Foundation of China, Grant No. 11505197
Recently, nitrogen doping (N-doping) technology has been proved to increase Q0 of superconducting cavity obviously, which lowers the BCS surface resistance. After N-doping, Q0 of 9-cell 1.3 GHz cavity can be increased to 3*10¹⁰ at Eacc = 16 MV/m, while 1.5*1010 without N-doping [1]. Since 2013, there have been over 60 cavities nitrogen doped at FNAL, JLAB and Cornell. The Circular Electron Collider (CEPC) has been proposed by IHEP in China, while requests Q0=4e10@Eacc=15.5 MV/m for 650 MHz cavity. It's hard to achieve without N-doping. So research of N-doping was begun in cooperation with Peking University in early 2015. Experiments of niobium samples have showed that nitrogen concentration at niobium surface increased a lot after N-doping. After then, several single-cell 1.3 GHz cavities completed vertical tests, but there're no successful test results of Q0 increasing, yet.

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WEPMB057

First Results of Magnetic Field Penetration Measurements on Multilayer S-I-S Structures

SRF, cavity, niobium, target

2245

O.B. Malyshev, K.D. Dumbell, L. Gurran, N. Pattalwar, S.M. Pattalwar, R. Valizadeh
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
A.V. Gurevich
ODU, Norfolk, Virginia, USA
L. Gurran
Lancaster University, Lancaster, United Kingdom
L. Gurran
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
O.B. Malyshev, S.M. Pattalwar, R. Valizadeh
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The performance of superconducting RF cavities made of bulk Nb is limited by a breakdown field of Bp=~200 mT, close to the superheating field for Nb. A potentially promising solution to enhance the breakdown field of the SRF cavities beyond the intrinsic limits of Nb is a multilayer coating suggested in [1]. In the simplest case, such a multilayer may be a superconductor-insulator-superconductor (S-I-S) coating, for example, bulk niobium (S) coated with a thin film of insulator (I) followed by a thin layer of another superconductor (S) which could be e.g. dirty niobium [2]. Here we report the first results of our measurements of field penetration in Nb thin films and Nb-AlN-Nb multilayer samples at 4.2 K using the magnetic field penetration facility designed, built and tested in ASTeC.

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WEPMR019

Development of Plasma Cleaning at Cornell University

plasma, cavity, SRF, superconductivity

2302

G.M. Ge, F. Furuta, M. Liepe, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Cornell University is developing the plasma cleaning technology as an alternative cleaning technique for SRF cavity surface preparation. In experiments, we successfully ignited the plasma in a single-cell SRF cavity. However the experiments were limited by the peak electric-fields in the RF coupler. In this paper, we show the analysis of the limitation and propose a new design of the coupler which can eliminate the limitation.

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WEPMR028

Studies on the Field Dependence of the BCS Surface Resistance

cavity, SRF, niobium, radio-frequency

2335

J.T. Maniscalco, D. Gonnella, G.H. Hoffstaetter, P.N. Koufalis, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Experiments have shown that the temperature-dependent portion of the RF surface resistance of SRF materials also exhibits a dependence on the magnitude of the surface field, manifested as a "Q-slope" or "anti-Q-slope" in the medium field region. Recent theoretical work proposes an explanation of the anti-Q-slope in dirty-limit superconductors. In this report, we compare theoretical predictions with the results of systematic experimental studies on the RF field dependence of the surface resistance using 1.3 GHz niobium SRF cavities with a wide range of mean free paths. We find very good agreement between theory and experiment in the dirty limit, with some divergence as the cavities approach the clean limit.

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WEPMR043

Analysis of Electrical Energy Consumption of Accelerator Reserach Facilities

operation, HOM, framework, neutron

2370

J. Stadlmann
GSI, Darmstadt, Germany
D. Batorowicz, C. Fuhr, J. Hanson, S. Leis
TUD, Darmstadt, Germany
M. Seidel
PSI, Villigen PSI, Switzerland

Funding: The work is part of EuCARD-2, partly funded by the European Commission, GA 312453.
Optimization of energy efficiency and utilization of renewable energy sources has become a major focus of political and social policies, leading to increasing energy cost not only in Germany but also in the European energy market. Simultaneously the energy demand of future accelerator projects is estimated to rise compared to existing facilities, leading to overall increased energy costs. Energy efficiency could counteract this trend by reducing energy consumption for a given research goal. This work aims to find recommendations for saving potential in existing research accelerators as well as guidelines for construction of future facilities. In order to identify and develop key figures for comparison between several international particle accelerator facilities, data has been collected by a questionnaire developed in cooperation between GSI and TUD, Darmstadt. We present the first results of it's evaluation.

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WEPMW001

End-to-End Beam Simulations for the New Muon G-2 Experiment at Fermilab

proton, target, storage-ring, simulation

2408

M. Korostelev, I.R. Bailey, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom
I.R. Bailey
Lancaster University, Lancaster, United Kingdom
A. Herrod, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
J.P. Morgan
Fermilab, Batavia, Illinois, USA
W. Morse, D. Stratakis, V. Tishchenko
BNL, Upton, Long Island, New York, USA

The aim of the new muon g-2 experiment at Fermilab is to measure the anomalous magnetic moment of the muon with an unprecedented uncertainty of 140 ppb. A beam of positive muons required for the experiment is created by pion decay. Detailed studies of the beam dynamics and spin polarization of the muons are important to predict systematic uncertainties in the experiment. In this paper, we present the results of beam simulations and spin tracking from the pion production target to the muon storage ring. The end-to-end beam simulations are developed in Bmad and include the processes of particle decay, collimation (with accurate representation of all apertures) and spin tracking.

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WEPMY003

Simulations of the Acceleration of Externally Injected Electrons in a Plasma Excited in the Linear Regime

electron, plasma, laser, acceleration

2542

N. Delerue, C. Bruni, S. Jenzer
LAL, Orsay, France
S. Kazamias, B. Lucas, G. Maynard
Laboratoire de Physique des Gaz et des Plasmas, Universite Paris-Sud, Orsay, France
M. Pittman
CLUPS, Orsay, France

We have investigated numerically the coupling between a 10 \si{MeV} electron bunch of high charge (§I{> 100}{pc}) with a laser generated accelerating plasma wave. Our results show that a high efficiency coupling can be achieved using a §I{50}{TW}, §I{100}{μ \meter} wide laser beam, yielding accelerating field above §I{1}{ GV/m}. We propose an experiment where these predictions could be tested.

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WEPMY005

Upgrades of the Experimental Setup for Electron Beam Self-modulation Studies at PITZ

plasma, laser, electron, acceleration

2548

M. Groß, J. Engel, G. Koss, O. Lishilin, G. Loisch, G. Pathak, S. Philipp, R. Schütze, F. Stephan
DESY Zeuthen, Zeuthen, Germany
R. Brinkmann, J. Osterhoff
DESY, Hamburg, Germany
F.J. Grüner
CFEL, Hamburg, Germany
F.J. Grüner
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
D. Richter
HZB, Berlin, Germany
C.B. Schroeder
LBNL, Berkeley, California, USA

The self-modulation instability is fundamental for the plasma wakefield acceleration experiment of the AWAKE collaboration at CERN where this effect is supposed to be used to generate proton bunches short enough for producing high acceleration fields. For ease of experimentation it was decided to set up a supporting experiment at the electron accelerator PITZ (Photo Injector Test facility at DESY, Zeuthen site), given that the underlying physics is the same. The goals are to demonstrate and investigate in detail the self-modulation of long electron beams. In 2015 a first set of experiments was conducted utilizing as key elements a novel cross-shaped lithium plasma cell and an ArF excimer laser for plasma generation. No self-modulation was observed yet because of various experimental shortcomings. The properties of the experimental setup were studied in detail and in this contribution we report about the upgrades which are projected to enable the observation of the self-modulation in the upcoming experimental run.

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WEPMY007

Plasma Density Profile Characterization for Resonant Plasma Wakefield Acceleration Experiment at SPARC_LAB

plasma, electron, laser, acceleration

2554

F. Filippi
INFN-Roma1, Rome, Italy
M.P. Anania, A. Biagioni, E. Chiadroni, M. Ferrario
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
INFN-Roma II, Roma, Italy
F. Filippi, A. Giribono, A. Mostacci, L. Palumbo
University of Rome La Sapienza, Rome, Italy
F. Filippi, A. Giribono, A. Mostacci, L. Palumbo
INFN-Roma, Roma, Italy
A. Giribono
University of Rome "La Sapienza", Rome, Italy
A. Zigler
The Hebrew University of Jerusalem, The Racah Institute of Physics, Jerusalem, Israel

New generation of particle accelerators is based on the excitation of large amplitude plasma waves driven by either electron or laser beams, named as Plasma Wakefield Accelerator (PWFA) and Laser Wakefield Accelerator (LWFA), respectively. Future experiments scheduled at the SPARC_LAB test facility aim to demonstrate the acceleration of externally injected high brightness electron beams through both schemes. In particular, in the so-called resonant PWFA a train of more than two driver electron bunches generated with the laser comb technique resonantly excites wakefields into the plasma, the last bunch (witness) is injected at the proper accelerating phase gaining energy from the wake. The quality of the accelerated beam depends strongly on plasma density and its distribution along the acceleration length. The desired density can be achieved with a correct shaping of the capillary in which plasma is formed. The measurements of plasma density, as well as other plasma characteristics, can be performed with spectroscopic measurements of the plasma self emitted light. The measurement of density distribution for hydrogen filled capillaries is here reported.

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WEPMY019

AWAKE, the Advanced Proton Driven Plasma Wakefield Acceleration Experiment

plasma, wakefield, laser, electron

2588

P. Muggli
MPI, Muenchen, Germany
C. Bracco
CERN, Geneva, Switzerland

The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment is currently being installed in the former CNGS facility and will use the 400 GeV/c proton beam bunches from the SPS to drive the wakefields in the plasma. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected to sample the wakefields and be accelerated with GeV/m gradients. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

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WEPMY021

Beam-Plasma Interaction Simulations for the AWAKE Experiment at CERN

plasma, proton, wakefield, electron

2596

A.V. Petrenko, E. Gschwendtner, G. Plyushchev, M. Turner
CERN, Geneva, Switzerland
K.V. Lotov
BINP SB RAS, Novosibirsk, Russia
K.V. Lotov, A. Sosedkin
NSU, Novosibirsk, Russia
G. Plyushchev
EPFL, Lausanne, Switzerland
M. Turner
TUG/ITP, Graz, Austria

The AWAKE experiment at CERN will be the first proof-of-principle demonstration of the proton-driven plasma wakefield acceleration using the 400 GeV proton beam extracted from the SPS accelerator. The plasma wakefield will be driven by a sequence of sub-millimeter long micro-bunches produced as a result of the self-modulation instability (SMI) of the 12 cm long SPS proton bunch in the 10 m long rubidium plasma with a density corresponding to the plasma wavelength of around 1 mm. A 16 MeV electron beam will be injected into the developing SMI and used to probe the plasma wakefields. The proton beam self-modulation in a wide range of plasma densities and gradients have been studied in detail via numerical simulations. A new configuration of the AWAKE experiment with a small plasma density step is proposed.

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WEPMY026

A Gas-filled Capillary Based Plasma Source for Wakefield Experiments

plasma, vacuum, high-voltage, simulation

2613

O. Mete Apsimon, K. Hanahoe, T.H. Pacey, G.X. Xia
UMAN, Manchester, United Kingdom

Funding: This work is supported by the University of Manchester Strategic Grant.
A plasma medium can be formed when a gas is discharged via an applied high voltage within a capillary tube. A high voltage discharge based plasma source for plasma wake- field acceleration experiment is being developed. Design considered a glass capillary tube with various inner radii. Glass was preferred to sapphire or quartz options to ease the machining. Electrodes will be attached to the tube using a sealant resistant to high vacuum conditions and baking at high temperatures. Each electrode will be isolated from the neighbouring one using nuts or washers from a thermoplastic polymer insulator material to prevent unwanted sparking outside of the tube. In this paper, general design considerations and possible working points of this plasma source are presented for a range of plasma densities from 1×10²⁰ to 1×10²² m^−3. Consideration was also given to plasma density diagnostic techniques due to critical dependence of accelerating gradient on plasma density.

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WEPMY027

Feasibility Study of Plasma Wakefield Acceleration at the CLARA Front End Facility

plasma, wakefield, simulation, accelerating-gradient

2617

K. Hanahoe, R.B. Appleby, Y. M. Li, T.H. Pacey, G.X. Xia
UMAN, Manchester, United Kingdom
B. Hidding
USTRAT/SUPA, Glasgow, United Kingdom
B. Kyle
University of Manchester, Manchester, United Kingdom
O. Mete Apsimon
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
J.D.A. Smith
Tech-X, Boulder, Colorado, USA

Funding: Cockcroft Institute Core Grant and STFC
Plasma wakefield acceleration has been proposed at the CLARA Front End (FE) facility at Daresbury Laboratory. The initial phase of the experiment will acceleration of the tail of a single electron bunch, and the follow-up experiment will study preserving a high quality beam based on a two-bunch acceleration scenario. In this paper, a concept for the initial experiment is outlined and detailed simulation results are presented.

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WEPOR017

A Micrometric Positioning Sensor for Laser-Based Alignment

laser, alignment, target, vacuum

2700

G. Stern, H. Mainaud Durand, D. Piedigrossi, M. Sosin
CERN, Geneva, Switzerland
A. Geiger, S. Guillaume
ETH, Zurich, Switzerland

The Compact Linear Collider requires 10 μm accuracy over 200m for the alignment of its components. Since current techniques based on stretched wire or water level are difficult to implement, other options are under study. We propose a laser alignment system using positioning sensors made of camera/shutter assemblies. The goal is to implement such a positioning sensor. The corresponding studies comprise design and calibration as well as investigations of measurement accuracy and precision. On the one hand, we describe mathematically the laser beam propagation, its interaction with the shutter and image processing. On the other hand, we present experiments done with the prototype of a positioning sensor. As a result, we give practical suggestions to build the positioning sensors and we describe a calibration protocol to be applied to all sensors before measuring. In addition, we deliver estimates for measurement accuracy and precision. Our work provides the first steps towards a full alignment system.

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WEPOR030

Gas Filled RF Resonator Hadron Beam Monitor for Intense Neutrino Beam Experiments

electron, plasma, cavity, radiation

2733

K. Yonehara, A.V. Tollestrup, R.M. Zwaska
Fermilab, Batavia, Illinois, USA
R.J. Abrams, R.P. Johnson, G.M. Kazakevich
Muons, Inc, Illinois, USA
H.M. Dinkel
University of Missouri, Columbia, Columbia, Missouri, USA
B.T. Freemire
IIT, Chicago, Illinois, USA

Funding: Work supported by Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359 and DOE HEP STTR Grant DE-SC0013795.
MW-class beam facilities are being considered all over the world to produce an intense neutrino beam for fundamental particle physics experiments. A radiation-robust beam monitor system is required to diagnose the primary and secondary beam qualities in high-radiation environments. We have proposed a novel gas-filled RF-resonator hadron beam monitor in which charged particles passing through the resonator produce ionized plasma that changes the permittivity of the gas. The sensitivity of the monitor has been evaluated in numerical simulation. A signal manipulation algorithm has been designed. A prototype system will be constructed and tested by using a proton beam at the MuCool Test Area at Fermilab.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR030

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WEPOR032

Power Recycling of Burst-mode Laser Pulses for Laser Particle Interactions

cavity, laser, resonance, ion

2739

Y. Liu, A. Rakhman
ORNL, Oak Ridge, Tennessee, USA
A. Rakhman
UTK, Knoxville, Tennessee, USA

Funding: This work has been partially supported by U.S. DOE grant DE-FG02-13ER41967. ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
A number of laser-particle interaction experiments such as the laser assisted hydrogen ion beam stripping or X-/γ-ray generations via inverse-Compton scattering involve light sources operating in a burst mode to match the temporal structure of the particle beam. As the small cross-section in the laser-particle interaction process results in negligible laser power loss, it is desirable to make the interaction inside an optical cavity to recycle the laser power. In many cases, conventional cavity locking techniques will not work since the burst normally has very small duty factor and low repetition rate and it is impossible to generate an effective control signal. In this talk, we report on the development of a doubly-resonant optical cavity scheme and its locking technique that enables a simultaneous resonance of two laser beams with different spectra and/or temporal structures. We demonstrate that such a cavity can be used to recycle burst-mode ultra-violet laser pulses with arbitrary burst lengths and repetition rates. System implementation, technical challenges, experimental results and applications will be described.
* V. Danilov et al., Phys. Rev. ST Accel. Beams 10, 053501 (2007).
** K. Sakaue et al., Rev. Sci. Instrum. 80, 123304 (2009).
*** A. Rakhman, M. Notcutt, and Y. Liu, Opt. Lett. 40, 5562 (2015).

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WEPOR051

Second Generation LHC Analysis Framework: Workload-based and User-oriented Solution

simulation, framework, factory, data-analysis

2784

S. Boychenko, C. Aguilera-Padilla, M.A. Galilée, J.C. Garnier, A.A. Gorzawski, K.H. Krol, J. Makai, M. Osinski, M.C. Poeschl, T.M. Ribeiro, A. Stanisz, M. Zerlauth
CERN, Geneva, Switzerland
M.Z. Rela
University of Coimbra, Coimbra, Portugal

Consolidation and upgrades of accelerator equipment during the first long LHC shutdown period enabled particle collisions at energy levels almost twice higher compared to the first operational phase. Consequently, the software infrastructure providing vital information for machine operation and its optimisation needs to be updated to keep up with the challenges imposed by the increasing amount of collected data and the complexity of analysis. Current tools, designed more than a decade ago, have proven their reliability by significantly outperforming initially provisioned workloads, but are unable to scale efficiently to satisfy the growing needs of operators and hardware experts. In this paper we present our progress towards the development of a new workload-driven solution for LHC transient data analysis, based on identified user requirements. An initial setup and study of modern data storage and processing engines appropriate for the accelerator data analysis was conducted. First simulations of the proposed novel partitioning and replication approach, targeting a highly efficient service for heterogeneous analysis requests, were designed and performed.

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WEPOW011

BESSY II Supports an Extensive Suite of Timing Experiments

synchrotron, operation, timing, photon

2840

R. Müller, T. Birke, F. Falkenstern, K. Holldack, P. Kuske, A. Schälicke, D. Schüler
HZB, Berlin, Germany
H.G. Glass, R. Ovsyannikov
BESSY GmbH, Berlin, Germany

The synchrotron light source facility BESSY II has put top-up and a fast orbit feedback (FOFB) into operation in 2013. Both operational improvements have matured and turned out to be especially beneficial for the advanced timing opportunities supported at BESSY. In combination with very tight injection efficiency requirements a thorough understanding of top-up injections under all operational conditions has been developed. Consequently arbitrary bunch currents can be dialed in and maintained on demand. In standard mode, a very pure camshaft bunch is available both in general for laser pump/X-ray probe and for pseudo single bunch experiments at the MHz chopper beamline. 3 constant high current bunches support the FEMTOSPEX slicing facility. An additional bunch can be resonantly excited and pulse picked via custom orbit bumps at 3 different undulator beamlines (PPRE). Due to the FOFB the classical timing modes "single bunch" and "low alpha" feature an attractive pointing stability.

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WEPOY002

A Time Domain Analysis Method for RF Noise

simulation, cavity, beam-loading, LLRF

2994

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

A time domain analysis method is developed for the calculation of the longitudinal oscillations caused by the RF noise in the storage ring. This method is based on the impulse response model, and it could calculates the change of transient field caused by beam oscillation and RF noise turn by turn. By means of discrete spectrum analysis, the spectrum of the beam is obtained. According to this analysis method, we developed a simulation pro-gram. The synchronous oscillation of the excited by high RF source with a phase modulation is predicted in this program, and the corresponding experimental measure-ments are carried out on HLS II. The fitting results are in agreed with the experimental measurements.

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WEPOY025

High Power RF Generation From a W-Band Corrugated Structure Excited by a Train of Electron Bunches

wakefield, electron, simulation, acceleration

3040

D. Wang, C.-X. Tang
TUB, Beijing, People's Republic of China
S.P. Antipov, C.-J. Jing, J.Q. Qiu
Euclid TechLabs, LLC, Solon, Ohio, USA
M.E. Conde, D.S. Doran, W. Gai, G. Ha, G. Ha, W. Liu, J.G. Power, E.E. Wisniewski
ANL, Argonne, Illinois, USA
V.A. Dolgashev
SLAC, Menlo Park, California, USA

We report on the generation of multi-megawatt peak RF power at 91textGHz, using an ultrarelativistic electron bunch train to excite electromagnetic fields in a high-impedance metallic corrugated structure. This device can be used as a power source for high gradient acceleration of electrons. To achieve precise control of the wakefield phase, a long range wakefield interferometry method was developed in which the RF energy due to the interference of the wakefields from two bunches was measured as a function of the bunch separation.

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WEPOY048

Overview of the Design of the IBEX Linear Paul Trap

ion, alignment, multipole, vacuum

3104

S.L. Sheehy
JAI, Oxford, United Kingdom
D.J. Kelliher, S. Machida, D.C. Plostinar, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

We report on the status and design of the Intense Beam Experiment (IBEX) at RAL. This experiment consists of a linear Paul trap apparatus similar to the S-POD system at University of Hiroshima, confining non-neutral Argon plasma in an RF quadrupole field. The physical equivalence between this device and a beam in a linear focusing channel makes it a useful tool for accelerator physics studies including resonances and high intensity effects. We give an overview of the design and construction of IBEX and outline plans for commissioning and the future experimental programme.

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WEPOY053

Comparison of Tracking Codes for the Determination of Dynamic Aperture in Storage Rings

dynamic-aperture, dipole, lattice, storage-ring

3114

R. Hipple, M. Berz
MSU, East Lansing, Michigan, USA

Funding: This work is supported by the U.S. Department of Energy under grant number DE-FG02-08ER41546
Currently there is a great deal of activity towards making precision measurements utilizing storage rings, for example the Muon g-2 experiment at Fermilab, and the Electric Dipole Moment (EDM) program of the JEDI Collaboration. These experiments are intended to perform measurements requiring sub-ppm precision. Of utmost importance in this regard is the ability of tracking codes to treat all nonlinear effects arising from the detailed field distributions present in the system, not the least of which are fringe fields. In previously published work,*,**, we performed parallel tests of various tracking codes in order to compare and contrast the results. In this study, we continue this line of research and extend the scope to parallel-faced dipoles and electrostatic dipoles.
* R.Hipple, M. Berz, Microscopy and Microanalysis 21 Suppl. 4 (2015)
** R. Hipple, M.Berz, MODBC3, ICAP 2015, in press.

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WEPOY060

YACS - Progression Towards Isoparametric 2.5D Finite Elements

cavity, software, synchrotron-radiation, radiation

3135

B.D. Isbarn, B. Riemann, M. Sommer, T. Weis
DELTA, Dortmund, Germany

Funding: Work supported by the BMBF under contract no. 05K13PEB.
YACS is a 2.5D finite element method solver capable of solving for the full 3D eigenfrequency spectra of resonant axisymmetric structures while reducing the computational problem to a 2D rotation plane. Prior studies and benchmarks, comparing YACS to well known commercial 3D and 2D applications, already demonstrated its capabilities of performing fast optimizations of geometries, due to its minimal computational overhead. However, because of the first order elements and basis functions used for approximation of the domain and field, this solving speed advantage vastly diminishes when targeting higher accuracies. In order to circumvent these issues, YACS was upgraded to support arbitrary order basis functions and curved meshes, leading to, but not limited to, isoparametric finite elements. This led to distinct performance and convergence improvements, especially when considering curved geometries, ideally representable by a polynomial mapping, e.g. when choosing a cavity geometry parametrization based on splines.

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THOAB02

Concept of RF Linac for Intra-pulse Multi-energy Scan

klystron, linac, electron, gun

3180

A.K. Krasnykh, J. Neilson, A.D. Yeremian
SLAC, Menlo Park, California, USA

Funding: Work supported in part by US Department of Energy under contract DE-AC02-76SF00515
A material discrimination based on X-Ray systems is typically achieved by alternating photon pulses of two different energies. A new approach relies on the ability to generate X-ray pulses with an end-point energy that varies in a controlled fashion during the duration of the pulse. An intra-pulse multi-energy X-ray beam device will greatly enhance current cargo screening capabilities. This method originally was described in the AS&E patents*. This paper addresses a linac concept for the proposed scan and describes some proof of concept experiments carried out at SLAC.
* A. Arodzero et al., 'System and methods for intra-pulse multi-energy and adaptive multi-energy X-ray cargo inspection', US Patent 8,457, 274, 2013

Slides THOAB02 [1.776 MB]

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THPMB004

Improving Energy Spread and Stability of a Recirculating Few-turn Linac

linac, electron, recirculation, synchrotron

3222

F. Hug
IKP, Mainz, Germany
M. Arnold, T. Kürzeder, N. Pietralla
TU Darmstadt, Darmstadt, Germany
R.G. Eichhorn
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Supported by the DFG through CRC 634, RTG 2128 and PRISMA cluster of excellence
A non-isochronous recirculation scheme which helps cancelling out errors coming from the RF-jitters in a recirculating linac will be presented. Non-isochronous recirculation is the common operation mode for synchrotrons or microtrons. In such a scheme the recirculation arcs provide a non-zero longitudinal dispersion, while the particle bunches are accelerated at a certain phase off-crest with respect to the maximum of the accelerating field. In few-turn linacs and microtrons such beam dynamics can be used to reduce the energy spread. To do so the longitudinal phase advance needs to be set to a half-integer number of oscillations in phase space. Then errors from linac RF-systems cancel out and the energy spread remains closely to the value at injection. In addition to the improved energy spread the beam stability of few-turn recirculators can be increased as well using such a system. We will present operational experience with the non-isochronous recirculation system of the twice recirculating superconducting accelerator S-DALINAC operated at TU Darmstadt including beam-dynamics calculations and measurements of the energy spread.

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THPMB011

Beam Based Alignment Methods for Cavities and Solenoids in Photo-Injectors

solenoid, cavity, target, linac

3247

M. Rossetti Conti
Universita' degli Studi di Milano & INFN, Milano, Italy
A. Bacci
Istituto Nazionale di Fisica Nucleare, Milano, Italy

Solenoids are often used as lens-like beam focusing elements in electron linacs, especially in the low energy beam lines aside the Gun solenoid for emittance compensation, a common element of high brightness photo-injectors. There are also many electron linacs worldwide which use the Velocity Bunching beam compression technique, which needs solenoids wrapping the first acceleration cavity. A misalignment between the beam trajectory and the magnetic center of the solenoids produces a decrease in the beam quality and makes it necessary to find a complex steering setting to force the beam on a good orbit. In this proceeding we present a study of two beam based alignment techniques, which are correlated: the first shows a method to find the correct electromagnetic axis of an acceleration cavity, the second shows how to align the solenoids (wrapping the cavity) on this axis. Therefore the study permits to find the best steering setting and the solenoids positions corrections which have to be done. The work is based on real data acquired on the SPARC linac and on a virtual experiment.

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THPMB047

Beam Dynamics Studies of the ELENA Electrostatic Transfer Lines in the Presence of Magnetic Stray Fields

antiproton, simulation, solenoid, quadrupole

3351

J. Jentzsch, W. Bartmann, M.A. Fraser, R. Ostojić, G. Tranquille
CERN, Geneva, Switzerland
D. Barna
University of Tokyo, Tokyo, Japan

The ELENA (Extra Low ENergy Antiproton) ring at CERN will further decelerate antiprotons produced at the AD (Antiproton Decelerator) facility from a kinetic energy of 5.3 MeV to 100 keV. The antiprotons will be distributed through a network of electrostatic transfer lines to several experiments, which will replace the existing magnetic transfer lines. The existing experiments and limited space in the AD hall forces the new transfer lines into close proximity to the high-field solenoids used by some experiments to trap the antiprotons. The stray fields from the experimental magnets are known to perturb beam delivery and are a concern for operation at the decreased beam rigidity provided by ELENA. A study was carried out to investigate the influence of stray magnetic fields on the beam, including different ramping periods and operational scenarios. The analytical model of the fields used for simulation will be discussed. Furthermore, trajectory correction algorithms using MADX optic model of the lines have been investigated. The results of these studies as well as specifications of acceptable stray field limits and field attenuation requirements will be presented.

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THPMB054

FFAG Beam Line for nuPIL - Neutrinos from PIon Beam Line

lattice, proton, target, detector

3372

J.-B. Lagrange, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
R.B. Appleby, S.C. Tygier
UMAN, Manchester, United Kingdom
R.B. Appleby
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A.D. Bross, A. Liu
Fermilab, Batavia, Illinois, USA
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The Long Baseline Neutrino Facilities (LBNF) program aims to deliver a neutrino beam for the Deep Underground Neutrino Experiment (DUNE). The current baseline for LBNF is a conventional magnetic horn and decay pipe system. Neutrinos from PIon beam Line (nuPIL) is a part of the optimization effort to optimize the LBNF. It consists of a pion beam line after the horn to clean the beam of high energy protons and wrong-sign pions before transporting them into a decay beam line, where instrumentation could be implemented. This paper focuses on the FFAG solution for this pion beam line. The resulting neutrino flux is also presented.

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THPMR005

Systematic Errors Investigation in Frozen and Quasi-Frozen Spin Lattices of Deuteron EDM Ring

lattice, sextupole, storage-ring, dipole

3394

V. Senichev, B. Lorentz
FZJ, Jülich, Germany
S.N. Andrianov, A.N. Ivanov
St. Petersburg State University, St. Petersburg, Russia
M. Berz, E. Valetov
MSU, East Lansing, Michigan, USA
S. Chekmenev, J. Pretz
RWTH, Aachen, Germany

The search for the electric dipole moment (EDM) in the storage ring raises two questions: how to create conditions for maximum growth of the total EDM signal of all particles in bunch, and how to differentiate the EDM signal from the induced magnetic dipole moment (MDM) signal. The T-BMT equation distinctly addresses each issue. Because the EDM signal is proportional to the projection of the spin on the direction of the momentum, it is desirable to freeze the spin direction of all particles in a bunch along momentum. It can be successfully implemented in the Quasi Frozen (QFS) and Frozen (FS) Spin structures. However, in case of magnet misalignments, the induced MDM signal may arise in the same plane as the EDM signal and thereby prevent its registration. In this paper, we analyze the effect of errors together with the spin-tune decoherence of all particles in the bunch for FS and QFS options.

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THPMR006

Muon Beam Tracking and Spin-Orbit Correlations for Precision g-2 Measurements

target, simulation, proton, dipole

3397

D. Tarazona, M. Berz, R. Hipple, K. Makino, M.J. Syphers
MSU, East Lansing, Michigan, USA
M.J. Syphers
Fermilab, Batavia, Illinois, USA

The main goal of the Muon g-2 Experiment (g-2) at Fermilab is to measure the muon anomalous magnetic moment to unprecedented precision. This new measurement will allow to test the completeness of the Standard Model (SM) and to validate other theoretical models beyond the SM. The close interplay of the understanding of particle beam dynamics and the preparation of the beam properties with the experimental measurement is tantamount to the reduction of systematic errors in the determination of the muon anomalous magnetic moment. We describe progress in developing detailed calculations and modeling of the muon beam delivery system in order to obtain a better understanding of spin-orbit correlations, nonlinearities, and more realistic aspects that contribute to the systematic errors of the g-2 measurement. Our simulation is meant to provide statistical studies of error effects and quick analyses of running conditions for when g-2 is taking beam, among others. We are using COSY, a differential algebra solver developed at Michigan State University that will also serve as an alternative to compare results obtained by other simulation teams of the g-2 Collaboration.

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THPMR017

Resonance Island Experiments at BESSY II for User Applications

undulator, photon, operation, resonance

3427

P. Goslawski, J. Feikes, K. Holldack, A. Jankowiak, M. Ries, M. Ruprecht, A. Schälicke, G. Wüstefeld
HZB, Berlin, Germany
R. Ovsyannikov
BESSY GmbH, Berlin, Germany

Beam storage close to a tune resonance (Qx = 1/3, 1/4) can generate resonance island buckets in the x,x' phase space providing a second stable island orbit winding around the standard orbit. Experiments with such an operation mode have been conducted at BESSY II and the Metrology Light Source (MLS)*,**. The two orbits are well separated, with good life time and stability. Such operation mode will offer additional operation flexibility and allows users to choose their radiation source point from one or the other orbit. It has the potential to fulfill simultaneously conflicting user demands, e.g., high vs. low beam current and single or few bunch filling vs. multibunch filling. We discuss the required beam optics setup and present successful measurements taken at photon beamlines at BESSY II.
* P. Goslawski et al., "Bunch Separation by Transverse Resonance Island Buckets", ESLS XXIII Workshop, 2015, Villigen, Switzerland.
** M. Ries et al., Proc. IPAC 2015, Richmond, USA, MOPWA021.

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THPMW002

Power Supplies for Main Magnet of J-PARC Main Ring

power-supply, controls, acceleration, extraction

3534

S. Nakamura, Y. Kurimoto, Y. Morita, T. Shimogawa
KEK, Ibaraki, Japan

A large magnetic field ripple of the order of 10^-2 were observed at the first beam commissioning of J-PARC main ring in 2008, To eliminate the ripple, we had improved the magnet power supplies by reconstructing a trap-filter of 600 Hz and adopting an additional DCCT. We made differencial circuit and symmetrical wiring for all magnets. On the other hand, acceleration period was reduced from 2.5 s to 1.4 s for increasing the beam power with feedforward control. We summarize the improvements of the magnet power supplies in this paper.

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THPMY007

Vacuum Performance of Amorphous Carbon Coating at Cryogenic Temperature with Presence of Proton Beams

electron, cryogenics, vacuum, simulation

3663

R. Salemme, V. Baglin, G. Bregliozzi, P. Chiggiato
CERN, Geneva, Switzerland

Amorphous carbon (a-C) coating is the baseline electron multipacting mitigation strategy proposed for the Inner Triplets (IT) in the High Luminosity upgrade of the Large Hadron Collider (HL-LHC). As of 2014, the COLD bore EXperiment (COLDEX) is qualifying the performance of a-C coating at cryogenic temperature in a LHC type cryogenic vacuum system. In this paper, the experimental results following a cryogenic vacuum characterization of a-C coating in the 5 to 150 K temperature range are reviewed. We discuss the dynamic pressure rise, gas composition, dissipated heat load and electron activity observed within an accumulated beam time of 9 Ah. The results of dedicated experiments including pre-adsorption of different gas species (H2, CO) on the a-C coating are discussed. Based of phenomenological modeling, up-to-date secondary emission input parameters for a-C coatings are retrieved for electron cloud build-up simulations. Finally, first implications for the HL-LHC ITs design are drawn.

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THPMY008

Mechanical and Vacuum Stability Studies for the LHC Experiments Upgrade

vacuum, ion, detector, simulation

3667

J. Sestak, G. Bregliozzi, P. Chiggiato
CERN, Geneva, Switzerland

In April 2015, the Large Hadron Collider (LHC) has entered its second operational period that will last for 3 years with expected end of the operations at the beginning of 2019. Afterward, the LHC will undergo a long shutdown (LS2) for upgrade and maintenance. The four LHC experiments, ATLAS, ALICE, CMS and LHCb, will experience an important upgrade too. From the design point of view, the LS2 experimental beam vacuum upgrade requires multi-disciplinary approach: based on the geometrical envelope defined by experiment, the vacuum chambers size and shape must be optimized. This included Monte Carlo pressure profile simulations and vacuum stability studies in order to meet the specific pressure requests in the interaction region. Together with vacuum studies the structural analysis are performed in order to optimise chambers thickness and position of the operational and maintenance supports. The material selection for vacuum chambers in the experimental area follows the CERN ALARA (as low as reasonably achievable) principle. This paper gives an overview of the LS2 experimental vacuum sectors upgrades. The most extensive design studies, done for the two experiments CMS and ALICE are discussed in detail.

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THPMY014

Study of the Non-evaporable Ti-Zr-V Films Grown on Different Materials

vacuum, electron, synchrotron-radiation, booster

3682

L.H. Wu, C.M. Cheng, Y.T. Huang, S.Y. Perng, I.C. Sheng, C. Shueh
NSRRC, Hsinchu, Taiwan

The non-evaporable (NEG) Ti-Zr-V films were coated on the different vacuum-chamber materials, including the extruded aluminum samples (Al), the extruded seamless stainless steel samples (S.S.), CuCrZr alloys, and oxygen-free copper (OFC) plates. The NEG films were fabricated by using the direct current (DC) sputtering method. The secondary electron microscopy images showed that the morphology of NEG films was different on these various substrates. The thermal analysis (TA) presented that exothermic reaction happened by heating the samples.

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THPMY018

Benchmarking and Calibration of Monte Carlo Vacuum Simulations with SynRad and MolFlow+

vacuum, photon, storage-ring, scattering

3695

J.A. Carter
ANL, Argonne, Ilinois, USA

The APS-Upgrade project is using SynRad and MolFlow+ to evaluate the vacuum system design for the future 6 GeV, 200 mA APS-Upgrade storage ring. The goal of this work is to explore PSD outgassing predictions from the two programs in order to build confidence in pressure calculations for the APS-U storage ring vacuum system. A study is performed on calibrating PSD measurements for aluminum vacuum chambers and then applying them to APS-U vacuum system calculations. The study reveals that a PSD measurement may not reveal a single unique behavior for a vacuum material and that multiple sources should be considered for vacuum calculations.

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THPMY023

The Hiradmat 27 Experiment: Exploring High-Density Materials Response at Extreme Conditions for Antiproton Production

target, antiproton, proton, instrumentation

3705

C. Torregrosa, M. Bergeret, E. Berthomé, M.E.J. Butcher, M. Calviani, L. Gentini, D. Horvath, J. Humbert, A. Perillo-Marcone, G. Vorraro
CERN, Geneva, Switzerland
C. Torregrosa
UPV, Valencia, Spain

The HRMT27-Rodtarg- experiment used the HiRadMat facility at CERN to impact intense 440 GeV proton beams onto thin rods -8 mm diameter, 140 length- made of high-density materials such as Ir, W, Ta, Mo among others. The purpose of the experiment has been to reduce uncertainties on the CERN antiproton target material response and assess the material selection for its future redesign. The experiment was designed to recreate the extreme conditions reached in the named target, estimated on an increase of temperature above 2000 °C in less than 0.5 μs and a subsequent compressive-to-tensile pressure wave of several GPa. The goals of the experiment were to validate the hydrocode calculations used for the prediction of the antiproton target response and to identify limits and failure mechanisms of the materials of interest. In order to accomplishing these objectives, the experiment counted on extensive online optical instrumentation pointing at the rod surfaces. Online results suggest that most of the targets suffer important internal damage even from conditions seven times lower than the reached in the AD-target. Tantalum targets clearly showed the best dynamic response.

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THPMY031

The Methods to Optimize Power Usage for Chiller System of TPS Utility

controls, operation, factory, synchrotron

3725

C.S. Chen, W.S. Chan, J.-C. Chang, Y.C. Chang, Y.-C. Chung, C.Y. Liu, Z.-D. Tsai
NSRRC, Hsinchu, Taiwan

The recently completed Taiwan Photon Source (TPS) is one of the brightest synchrotron X-ray sources in the world. It will offer 500 mA beam current at 3 GeV for all kinds of different subject experiments and novel scientific ideas. This facility will be the most inspiring trigger to Taiwan's scientific research in the twenty-first century. In order to make sure this giant machine operate properly, the utility system plays a very important role. Not only for the giant machine, the utility system also takes responsibility for providing a cozy environment for all staff. Furthermore, the requirements of air condition in some critical areas are very strict even to ± 0.1°C temperature accuracy. All of it cost a large amount of energy to satisfy everyone's demand. According to the annual budget report of NSRRC, the total charge of electricity and water was more than 80 million N.T. dollars per year before TPS project, and increased by nearly twice after TPS inauguration. Since the government budget is limited, the whole utility system must be operated under more economic ways to use energy more efficiently.

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THPOR020

Status of VEPP-4M Collider

photon, injection, storage-ring, detector

3818

E.B. Levichev, O.I. Meshkov, P.A. Piminov, A.N. Zhuravlev
BINP SB RAS, Novosibirsk, Russia

At present the VEPP-4 storage ring facility provides varied experimental programs including HEP, nuclear physics, synchrotron radiation, polarized electron/positron beam research, etc. Until now, the studies were mainly performed at the beam energy below 2 GeV but a strong interest of experimentalists encourages us to increase the beam energy up to 5 GeV. Reliable and high-performance operation at high energy is a challenge for the machine. Here we discuss the recent experimental results at the low energy, and prospects and constraints of the energy ramp.

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THPOR025

Wedge Absorbers for Final Cooling for a High-Energy High-Luminosity Lepton Collider

emittance, optics, betatron, collider

3832

D.V. Neuffer
Fermilab, Batavia, Illinois, USA
T.A. Mohayai
IIT, Chicago, Illinois, USA
P. Snopok
Illinois Institute of Technology, Chicago, Illinois, USA
D.J. Summers
UMiss, University, Mississippi, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the U. S. Department of Energy.
A high-energy high-luminosity muon collider scenario requires a "final cooling" system that reduces transverse emittance to ~25 microns (normalized) while allowing longitudinal emittance increase. Ionization cooling using high-field solenoids (or Li Lens) can reduce transverse emittances to ~100 microns in readily achievable configurations, confirmed by simulation. Passing these muon beams at ~100 MeV/c through cm-sized diamond wedges can reduce transverse emittances to ~25 microns, while increasing longitudinal emittance by a factor of ~5. Implementation will require optical matching of the exiting beam into downstream acceleration systems.

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THPOR031

Beam-Loading Effect on Breakdown Rate in High-Gradient Accelerating Structures

beam-loading, klystron, linac, controls

3848

F. Tecker, T. Argyropoulos, N. Catalán Lasheras, R. Corsini, A. Degiovanni, D. Gamba, J. Giner Navarro, A. Grudiev, G. McMonagle, J.L. Navarro Quirante, R. Rajamaki, E. Senes, I. Syratchev, B.J. Woolley, W. Wuensch
CERN, Geneva, Switzerland
T. Argyropoulos, J. Giner Navarro
IFIC, Valencia, Spain
A. Degiovanni, J.L. Navarro Quirante
ADAM, Geneva, Switzerland
D. Gamba
JAI, Oxford, United Kingdom
R. Rajamaki
Aalto University, School of Science and Technology, Aalto, Finland
E. Senes
Torino University, Torino, Italy
J. Tagg
National Instruments Switzerland, Ennetbaden, Switzerland

The Compact Linear Collider (CLIC) study for a future electron-positron collider with a center-of-mass energy up to 3 TeV aims for an accelerating gradient of 100 MV/m. The gradient is limited by RF breakdowns, and the luminosity requirements impose a limit on the admissible RF breakdown rate. RF testing of 12 GHz structure prototypes has shown that gradients in excess of 100 MV/m can be reached with the required breakdown rate. However at CLIC, the structures will be operated with significant beam-loading, modifying the field distribution inside. The effect of the beam-loading must be well understood but has not been previously measured. The commissioning and operation of an experiment to measure the effect of beam-loading on breakdown rate and the measurement results are presented.

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THPOR041

High Gradient Properties of a CLIC Prototype Accelerating Structure made by Tsinghua University

operation, timing, accelerating-gradient, vacuum

3874

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

A CLIC prototype structure, T24_THU_#1, was recently high-gradient tested at KEK X-band test stand, Nextef. The copper parts of this 24-cell TW structure were delivered from CERN, were bonded and brazed, bench-tested and tuned in Tsinghua University. The aim of this test was not only to verify the cavity high-gradient properties under 100 MV/m but also to study the breakdown phenomenon in high gradient. High power test results were presented and breakdown rate under 100 MV/m was compared to previously-tested CLIC prototype structures. The assembly capability of Tsinghua University for X-band high gradient structures was validated by the good high gradient performance of T24_THU_#1.

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THPOR042

New Quantity Describing the Pulse Shape Dependence of the High Gradient Limit in Single Cell Standing-Wave Accelerating Structures

operation, vacuum, radiation, data-analysis

3878

J. Shi, H.B. Chen, X.W. Wu
TUB, Beijing, People's Republic of China
V.A. Dolgashev
SLAC, Menlo Park, California, USA
A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland
Y. Higashi
KEK, Ibaraki, Japan
B. Spataro
INFN/LNF, Frascati (Roma), Italy

A new quantity has been developed to study the relationship among the breakdown rate, the pulse width and the gradient. Difference pulse shapes can be treated by introducing a Green's function. This paper describes the quantity and the results while it is applied to the data of many high-power test runs of different single-cell standing wave accelerating structures. A remarkably similar relationship between the new quantity and breakdown rate is observed from all of the test results.

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THPOR044

mm-Wave Standing-Wave Accelerating Structures for High-Gradient Tests

accelerating-gradient, cavity, plasma, RF-structure

3884

E.A. Nanni, M. Dal Forno, V.A. Dolgashev, J. Neilson, S.G. Tantawi
SLAC, Menlo Park, California, USA
S.C. Schaub
MIT, Cambridge, Massachusetts, USA
R.J. Temkin
MIT/PSFC, Cambridge, Massachusetts, USA

We present the design and parameters of single-cell accelerating structures for high-gradient testing at 110 GHz. The purpose of this work is to study the basic physics of ultrahigh vacuum RF breakdown in high-gradient RF accelerators. The accelerating structures consist of pi-mode standing-wave cavities fed with TM01 circular waveguide mode. The geometry and field shape of these accelerating structures is as close as practical to single-cell standing-wave X-band accelerating structures, more than 40 of which were tested at SLAC. This wealth of X-band data will serve as a baseline for these 110 GHz tests. The structures will be powered from a pulsed MW gyrotron oscillator. One MW of RF power from the gyrotron may allow us to reach a peak accelerating gradient of 400 MeV/m.

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THPOW005

A Study of CsK2Sb Multi-alkali Photocathode by Ultraviolet Photoelectron Spectroscopy at UVSOR

cathode, electron, laser, vacuum

3934

M. Urano, M. Kuriki, K. Negishi
HU/AdSM, Higashi-Hiroshima, Japan
T. Konomi, Y. Seimiya, N. Yamamoto
KEK, Ibaraki, Japan

Photocathode is one of the most important components in the next-generation accelerators, especially based on linear accelerators. Photocathode performance depends not only on electronic state in its bulk material but also on the surface condition. CsK2Sb multi-alkali photocathode is a candidate for the high brightness electron source because of its high quantum efficiency by green laser and its high robustness. We have carried out an UPS (UV Photoelectron Spectroscopy) experiment at UVSOR facility, synchrotron radiation light source in Aichi Japan. We have compared the UPS spectra among several samples, each one has a different quantum efficiency, and try to find physics which decide photocathode's performance. In this case, we focused some characters correlated to the quantum efficiency. I'm going to present a result of this analysis.

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THPOW019

Beam Characterisation and Machine Developments at VELA

gun, cathode, electron, space-charge

3975

D. Angal-Kalinin, A.D. Brynes, F. Jackson, S.P. Jamison, J.K. Jones, J.W. McKenzie, B.L. Militsyn, B.D. Muratori, T.C.Q. Noakes, M.D. Roper, Y.M. Saveliev, D.J. Scott, R.J. Smith, E.W. Snedden, P.H. Williams
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S.D. Barrett, C.P. Topping, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
C.S. Edmonds, F. Jackson, S.P. Jamison, J.K. Jones, J.W. McKenzie, B.D. Muratori, Y.M. Saveliev, D.J. Scott, C.P. Topping, P.H. Williams, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom

An overview is presented of developments on VELA (Versatile Electron Linear Accelerator), an RF photo-injector with two user stations at Daresbury Laboratory. Numerous commissioning, machine development, beam characterisation and user experiments have been completed in the past year. A new beamline and a dedicated multiuser station have been commissioned and the first experiments performed. A number of measures have been taken to improve the stability of machine by mitigating a phase drift, laser beam transport drift and a coherent ~1 Hz beam oscillation. The 6D phase space of the electron beam has been characterised through quad scans, transverse tomography and with a transverse deflecting cavity.

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THPOW021

Generation of Homogeneous and Patterned Electron Beams using a Microlens Array Laser-Shaping Technique

laser, electron, emittance, solenoid

3983

A. Halavanau, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
D.R. Edstrom, P. Piot, J. Ruan, J.K. Santucci
Fermilab, Batavia, Illinois, USA
W. Gai, G. Ha, J.G. Power, E.E. Wisniewski
ANL, Argonne, Illinois, USA
G. Ha
POSTECH, Pohang, Kyungbuk, Republic of Korea
G. Qiang
TUB, Beijing, People's Republic of China

Funding: Northern Illinois University - US DOE contract No. DE-SC0011831. Fermilab - US DOE contract No. DE-AC02-07CH11359. The Argonne wakefield facility - US DOE contract No. DE-AC02-06CH11357.
In photocathodes the achievable electron-beam parameters are controlled by the laser used to trigger the photoemission process. Non-ideal laser distribution hampers the final beam quality. Laser inhomogeneities, for instance, can be "amplified" by space-charge force and result in fragmented electron beams. To overcome this limitation laser shaping methods are routinely employed. In the present paper we demonstrate the use of simple microlens arrays to dramatically improve the transverse uniformity. We also show that this arrangement can be used to produce transversely-patterned electron beams. Our experiments are carried out at the Argonne Wakefield Accelerator facility.

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THPOW054

Cumulative Damage of Ultrafast Laser Pulses

laser, vacuum, site, electron

4066

A. Hanuka, L. Schächter
Technion, Haifa, Israel
R.J. England, I.V. Makasyuk, K. Soong, K.P. Wootton, Z. Wu
SLAC, Menlo Park, California, USA

We demonstrate experimentally that damage threshold fluence (DTF) for fused silica changes with the number of femtosecond laser (10Hz 600Hz, 655 fs, 800nm) shots. Based on the experimental data we were able to develop a model which indicates that the change in DTF varies with number of shots logarithmically (ln^p) up to a critical value. Above this value, DTF approaches an asymptotic value. Both DTF for a single shot and the asymptotic value as well as the critical value where this happens are extrinsic parameters dependent on the configuration (repetition rate, pressure and geometry near or at the surface). Indications are that the power of this dependence (p) is an intrinsic parameter independent of the configuration.

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THPOW057

Direct High Power Laser Diagnostic Technique on Focused Electron Bunch

laser, electron, scattering, solenoid

4073

D. Igarashi, A. Endo, K. Sakaue, T. Takahashi, M. Washio
RISE, Tokyo, Japan

In laser produced plasma EUV source, high intensity pulse CO2 laser is essential for plasma generation. To achieve high conversion efﬁciency and stable EUV power, we would like to measure a laser proﬁle in the interaction point. However, there is no way to measure directly the laser profile of such a high intensity laser at the focus point. Therefore, we have been developing laser profiler based on laser Compton scattering(LCS). LCS signal by using focused electron beam shows 1D laser profile. 2D laser profile can be reconstructed by one-dimensional laser profiles from various angles using computer tomography. This method is suitable for high intensity laser, but very small spot size of electron beam is required. To obtain small spot size, we used S-band Cs-Te photocathode RF-Gun and specially designed solenoid lens at Waseda university. We already succeeded in observing minimum beam size of about 20 μm rms and this is adequate to scan the CO2 laser. In this conference, we will report the result of the laser Compton scattering with pulse CO2 laser, the preparatory experiment in measuring a metal wire cross section and the present progresses.

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THPOY026

Recent Challenges for the 1.5 GeV MAMI-C Accelerator at JGU Mainz

electron, polarization, operation, microtron

4149

M. Dehn, K. Aulenbacher, H.-J. Kreidel, F. Nillius, B.S. Schlimme, V. Tioukine
IKP, Mainz, Germany

Funding: Work supported by DFG (CRC 1044) and the German federal state of Rhineland-Palatinate
The MAMI-C accelerator is a 1.5 GeV microtron cascade for up to 100 μA polarised electrons operating CW at Mainz University. Recent experiments required spin manipulations and beam energies not routinely supported by the accelerator. In particular, this required a spin orientation vertical to the accelerator plane and operation at beam energies which could not be achieved by the so far established methods. This paper describes the challenges to provide and to characterise the unusual modes of operation.

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THPOY031

A Holistic Approach to Accelerator Reliability Modeling

database, extraction, network, real-time

4163

M. Reščič, R. Seviour
University of Huddersfield, Huddersfield, United Kingdom
W. Blokland
ORNL, Oak Ridge, Tennessee, USA

Reliability has been identified as a key factor limiting the development of certain particle accelerator applications, for example Accelerator-Driven Systems (ADS) for energy production and waste-transmutation*. Previous studies of particle accelerator reliability have been undertaken using conventional techniques, such as Reliability Block Diagrams (RBD), Fault Tree Analysis (FTA), etc. Although limited data surrounding components and their failure modes limits the applicability of conventional techniques for analysing the reliability of particle accelerators. In addition industrial applications of particle accelerators, i.e. energy production, require a real time response to failure. In this paper we examine a holistic approach to accelerator reliability modelling using Electric Network Frequency (ENF) criterion to look for emergent behaviour of the particle accelerator, from complex datasets, such as beam current/charge, created by the diagnostics systems during the machines operation. To look for predictive characteristics just prior to a machine trip.
* Report from the DOE ADS White Paper Working Group, Stuart Henderson, Fermilab, October 26, 2011

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THPOY044

Experimental Setup to Measure the Damage Limits of Superconducting Magnets due to Beam Impact at CERN's HiRadMat Facility

beam-losses, dipole, proton, target

4200

D. Kleiven
Kleiven, David, Geneva, Switzerland
B. Auchmann, V. Raginel, R. Schmidt, A.P. Verweij, D. Wollmann
CERN, Geneva, Switzerland

Funding: Research supported by the High Luminosity LHC project
The future upgrade of CERN's injector chain for the Large Hadron Collider (LHC) will lead to an increase of the beam brightness in the LHC. Beam absorbers are capturing missteered beams, but some limited beam impact on superconducting magnets can hardly be avoided. Therefore, it is planned to measure the damage limits of superconducting magnet components due to beam impact at CERN's HiRad- Mat facility using the 440 GeV proton beam from the Super Proton Synchrotron. Two experiments are proposed. One at ambient and one at cryogenic temperatures, where several pre-stressed stacks of LHC main dipole Nb-Ti cables and some single strands will be irradiated with varying beam intensities. The electrical integrity and the degradation of critical current will be measured after the removal from the HiRadMat facility. In the cold experiment some sample magnets will be added and the degradation of performance will be monitored online. In this contribution the experimental setup of the first experiment, including the sample container and cable stacks, is presented.

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THPOY050

Time Response of a Gridded X-ray Beam Ionization Chamber

ion, electron, radiation, photon

4220

Y.H. Xu, Z.H. Sun
DongHua University, Songjiang, People's Republic of China
D.V. Campen, W.J. Corbett
SLAC, Menlo Park, California, USA
C.L. Li
East China University of Science and Technology, Shanghai, People's Republic of China
W.J. Zhang
University of Saskatchewan, Saskatoon, Canada

Recently, Quick-Scanning Extended X-ray Absorption Spectroscopy (QEXAS) has become an important tool for in-situ characterization of materials and measurement of associated electronic structure. In this case the time response of the ionization chamber affects the measurement resolution and therefore overall performance of the QEXAS system. Common parallel-plate ionization chambers have a step-response rise time of about 0.1 sec, which does not meet the requirements of QEXAS. To speed up the response, we constructed a gridded ionization chamber with variable bias voltage and optional background gas (N2 or He, respectively). To characterize the system we used a high-frequency beam chopper upstream of the ionization chamber and a high-speed, low-noise preamplifier to measure the step response of the chamber as a function of bias voltage and background gas conditions.

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FRXCB01

Two Beam Wakefield Acceleration at Argonne Wakefield Accelerator Facility

wakefield, acceleration, electron, laser

4258

W. Gai
ANL, Argonne, Illinois, USA

Structure based wakefield acceleration provides a viable approach capable of accelerating a sufficient electrons and positrons in a substantially high graident needed to meet the luminosity, efficiency, and cost requirements of a future linear collider. The short pulse Two Beam wakefield Acceleration (TBA) studied at the Argonne Wakefield Accelerator Facility is aimed to pave the way toward the next linear collider. Here we present the latest results including the 100MeV/m of the single stage TBA and the staged TBA in which a 0.5nC bunch gained equal amount of energy in two stages (~2.4 MeV per stage, corresponding to an average acceleration gradient ~70 MeV/m). The technique is scalable to a staged-acceleration at 200-300MeV/m by using a GeV-scale drive beam. Such a development will considerably reduce both cost and footprint of a future high-energy physics collider as well as future X-Ray light source.

Slides FRXCB01 [11.937 MB]

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