IBIC2014 - List of Keywords (electron)

Paper	Title	Other Keywords	Page
MOCYB1	Non-Destructive Vertical Halo Monitor on the ESRF’s 6GeV Electron Beam	scattering, dipole, emittance, detector	2
	K.B. Scheidt ESRF, Grenoble, France
	The population density along the electron’s beam vertical profile at far distance from the central core (i.e. the far-away tails or “halo”) is now quantitatively measurable by the use of bending magnet X-rays. An available beamport is equipped with two specifically adapted absorbers, an Aluminium UHV window, an X-ray light blocker, an X-ray imager, and a few motorizations. The simple and inexpensive set-up (much resembling that of an X-ray pinhole camera system for emittance measurements in Light Sources, but much shorter in length) allows the recording of images of the electron density profile over the 0.5 to 6mm distance range from the core. Results, obtained under various manipulations on the electron beam to vary either Touchek or residual Gas scattering and thereby the Halo levels, will be presented, to fully demonstrate that this Halo monitor is exploring those realms of the beam where other diagnostics can not reach .
	Slides MOCYB1 [2.830 MB]
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MOCYB2	Design and Initial Commissioning of Beam Diagnostics for the KEK Compact ERL	linac, radiation, optics, emittance	7
	R. Takai, T. Honda, T. Nogami, T. Obina, H. Sagehashi, Y. Tanimoto, M. Tobiyama KEK, Ibaraki, Japan
	A compact energy-recovery linac (cERL) was constructed at KEK as a test accelerator for the ERL-based light source. Standard beam monitors such as beam position monitors (BPMs), screen monitors (SCMs), and beam loss monitors (BLMs) have been developed for the cERL and used in its commissioning. For the main BPMs, we adopted the stripline type, the time response of which is improved by using a glass-sealed feedthrough. The SCMs are equipped with two types of screens and an RF shield for wake-field suppression. Optical fibers with photomultiplier tubes (PMTs), covering the entire cERL circumference, are used as the BLM. CsI scintillators with large-cathode PMTs are also prepared for detecting local beam loss. The design and some initial commissioning results of these standard monitors are described in this paper.
	Slides MOCYB2 [4.987 MB]
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MOCYB3	Longitudinal Laser Wire at SNS	laser, ion, background, controls	12
	A.P. Zhukov, A.V. Aleksandrov, Y. Liu ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. This paper describes a longitudinal H⁻ beam profile scanner that utilizes laser light to detach convoy electrons and an MCP to collect and measure these electrons. The scanner is located in MEBT with H⁻ energy of 2.5MeV and an RF frequency 402.5MHz. The picosecond pulsed laser runs at 80.5MHz in sync with the accelerator RF. The laser beam is delivered to the beam line through a 30m optical fiber. The pulse width after the fiber transmission measures about 10ps. Scanning the laser phase effectively allows measurements to move along ion bunch longitudinal position. We are able to reliably measure production beam bunch length with this method. The biggest problem we have encountered is background signal from electrons being stripped by vacuum. Several techniques of signal detection are discussed.
	Slides MOCYB3 [4.519 MB]
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MOCZB3	Comparison of Feedback Controller for Link Stabilizing Units of the Laser Based Synchronisation System used at the European XFEL	controls, laser, feedback, timing	34
	M. Heuer, S. Pfeiffer, H. Schlarb DESY, Hamburg, Germany G. Lichtenberg HAW, Hamburg, Germany
	The European X-ray Free Electron Laser will allow scientists to perform experiments with an atomic scale resolution. To perform time resolved experiments at the end of the facility it is essential to provide a highly stable clock signal to all subsystems. The accuracy of this signal is extremely important since it defines limitations of precise measurement devices. A laser based synchronization system is used for the synchronization with an error in sub-femtosecond range. These light pulses are carried by an optical fiber and exposed to external disturbances which changes the optical length of the fiber. For that reason the up to 4 kilometer long fibers are actively stabilized using a controller implemented on the new MicroTCA Platform. Due to the high computation resources of this platform it is possible to attack the time delay of the link system with well known model based feedback control strategies. This contribution shows the design of a model based controller for such a system and compares the control performance of the previously used PID controller with advanced control algorithms at the currently installed laboratory setup.
	Slides MOCZB3 [4.973 MB]
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MOPF02	RHIC-Style IPMs in the Brookhaven AGS	detector, dipole, injection, acceleration	39
	R. Connolly, W.C. Dawson, J.M. Fite, H. Huang, S.E. Jao, W. Meng, R.J. Michnoff, S. Tepikian BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. Department of Energy. Beam profiles in the two storage rings of the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Lab (BNL) are measured with ionization profile monitors (IPMs). An IPM measures the distribution of electrons produced by beam ionization of background gas. These detectors have been developed at BNL in a program that began in 1996. The current detectors are a design from 2009. During the 2012 shutdown we refurbished the 2009 prototype detector and installed it in the Alternating-Gradient Synchrotron (AGS) for horizontal profiles. The commissioning tests were successful and in 2013 we built a new IPM for vertical profiles. In addition we placed coils on the backlegs of the permanent-magnet dipoles for beta-function measurements. This paper describes the AGS IPMs and shows data from the detector commissioning.
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MOPF05	Instrumentation for the Proposed Low Energy RHIC Electron Cooling Project with Energy Recovery	ion, emittance, gun, linac	49
	D.M. Gassner, A.V. Fedotov, R.L. Hulsart, D. Kayran, V. Litvinenko, R.J. Michnoff, T.A. Miller, M.G. Minty, I. Pinayev, M. Wilinski 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 There is a strong interest in running RHIC at low ion beam energies of 7.7-20 GeV/nucleon [1]; this is much lower than the typical operations with 100 GeV/nucleon. The primary motivation for this effort is to explore the existence and location of the critical point on the QCD phase diagram. Electron cooling can increase the average integrated luminosity and increase the length of the stored lifetime. A cooling system is being designed that will provide a 30 – 50 mA electron beam with adequate quality and an energy range of 1.6 – 5 MeV. The cooling facility is planned to be inside the RHIC tunnel. The injector will include a 704 MHz SRF gun, a 704 MHz 5-cell SRF cavity followed by a normal conducting 2.1 GHz cavity. Electrons from the injector will be transported to the Yellow RHIC ring to allow electron-ion co-propagation for ~20 m, then a 180 degree U-turn electron transport so the same electron beam can similarly cool the Blue ion beam. After the cooling process with electron beam energies of 1.6 to 2 MeV, the electrons will be transported directly to a dump. When cooling with higher energy electrons between 2 and 5 MeV, after the cooling process, they will be routed through the acceleration cavity again to allow energy recovery and less power deposited in the dump. Special consideration is given to ensure overlap of electron and ion beams in the cooling section and achieving the requirements needed for cooling. The instrumentation systems described will include current transformers, beam position monitors, profile monitors, an emittance slit station, recombination and beam loss monitors.
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MOPF08	Beam Profile Measurements in the RHIC Electron Lens using a Pinhole Detector and YAG Screen	controls, software, detector, timing	59
	T.A. Miller, M.R. Costanzo, W. Fischer, B. Frak, D.M. Gassner, X. Gu, A.I. Pikin 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 The electron lenses installed in RHIC are equipped with two independent transverse beam profiling systems, namely the Pinhole Detector and YAG screen. A small Faraday cup, with a 0.2mm pinhole mask, intercepts the electron beam while a pre-programmed routine automatically raster scans the beam across the detector face. The collected charge is integrated, digitized and stored in an image type data file that represents the electron beam density. This plungeable detector shares space in the vacuum chamber with a plunging YAG:Ce crystal coated with aluminum. A view port at the downstream extremity of the Collector allows a GigE camera, fitted with a zoom lens, to image the crystal and digitize the profile of a beam pulse. Custom beam profiling software has been written to import both beam image files (pinhole and YAG) and fully characterize the transverse beam profile. The results of these profile measurements are presented here along with a description of the system and operational features. * W. Fischer, et al, "… head-on beam-beam compensation in RHIC", ICFA (BB3013), CERN (2013). **T. Miller, et al, “… eLens pin-hole detector and YAG…“, BIW2012, Newport News, VA, TUPG039
	Poster MOPF08 [6.731 MB]
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MOPF10	A Compact In-Air X-Ray Detector for Vertical Beam Size Measurement at ALBA	photon, dipole, detector, storage-ring	69
	A.A. Nosych, U. Iriso ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	An in-air x-ray detector (IXD) was developed for ALBA to study the residual x-rays after traversing the 35mm copper crotch absorbers. The device prototype is placed in-air after such absorber, mounted flush with the vacuum pipe. The remaining x-rays (above 120 keV) generate a visible footprint if they impinge upon a sensitive enough scintillator. We are using a Cerium doped PreLude 420 (LuYSiO:Ce) screen, and the image is observed with a simple optics system mounted on a commercial CCD camera. This measurement allows evaluating the vertical electron beam size with exposure times in the order of seconds. Similar instruments are used at ESRF and ANKA storage rings. This paper presents the results of the first measurements with IXD and describes its potential to be used as a full diagnostics tool for the 3 GeV storage ring of ALBA.
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MOPF14	Vertical Beam Size Measurement at CesrTA Using Diffraction Radiation	target, radiation, background, polarization	77
	L.M. Bobb, T. Aumeyr, P. Karataev JAI, Egham, Surrey, United Kingdom T. Aumeyr, P. Karataev Royal Holloway, University of London, Surrey, United Kingdom M.G. Billing, J.V. Conway Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA L.M. Bobb DLS, Oxfordshire, United Kingdom E. Bravin, T. Lefèvre, S. Mazzoni, H. Schmickler CERN, Geneva, Switzerland
	Over recent years the first Diffraction Radiation (DR) beam size monitor has been tested on a circular machine. At CesrTA, Cornell University, USA, the sensitivity and limitations of the DR monitor for vertical beam size measurement has been investigated. DR emitted from 1 and 0.5 mm target apertures was observed at 400 and 600 nm wavelengths. In addition, interference between the DR signals emitted by the target and mask has been observed. In this report, we present the recent observations and discuss areas for improvement.
	Poster MOPF14 [3.379 MB]
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MOPF15	Status of and Future Plans for the CERN LINAC4 Emittance Meter based on Laser Electron-Detachment and a Diamond Strip-Detector	detector, laser, linac, emittance	83
	T. Hofmann, E. Bravin, U. Raich, F. Roncarolo, F. Zocca CERN, Geneva, Switzerland G.E. Boorman, A. Bosco, S.M. Gibson, K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom E. Griesmayer CIVIDEC Instrumentation, Wien, Austria
	Funding: LA3NET is funded by the European Commission under Grant Agreement Number GA-ITN-2011-289191 LINAC4 has started its staged commissioning at CERN. After completion it will accelerate high brightness H⁻ beams to 160 MeV. To measure the transverse profile and emittance of the beam, a non-destructive method based on electron photo-detachment is proposed, using a pulsed, fibre-coupled laser to strip electrons from the H⁻ ions. The laser can be focused and scanned through the H⁻ beam, acting like a conventional slit. A downstream dipole separates the neutral H⁰ beamlet, created by the laser interaction, from the main H⁻ beam, so that it can be measured by a diamond strip-detector. Combining the H⁰ beamlet profiles with the laser position allows the transverse emittance to be reconstructed. A prototype of this instrument was tested while commissioning the LINAC4 at 3 and 12 MeV. In this paper we shall describe the experimental setup, challenges and results of the measurements, and also address the characteristics and performance of the diamond strip-detector subsystem. In addition, the proposal for a permanent system at 160 MeV, including an electron detector for a direct profile measurement, will be presented.
	Poster MOPF15 [0.994 MB]
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MOPF22	Simultaneous Operation of Two FEL Undulator Beamlines at FLASH	undulator, laser, FEL, operation	103
	S. Ackermann, V. Ayvazyan, B. Faatz, E. Hass, K. Klose, S. Pfeiffer, M. Scholz, S. Schreiber DESY, Hamburg, Germany
	The FLASH FEL User Facility at DESY (Hamburg) is driven by a Photocathode RF gun and superconducting RF structures, producing up to 800 electron bunches per train with a repetition rate of 10 Hz. Because not all user experiments need the full pulse train (8000 FEL pulses per second), part of the electron bunches can be deflected into a second beamline, which can simultaneously deliver FEL pulses with different parameters to a second user experiment. To realize this possibility, the FLASH facility has been upgraded with a second undulator line and a second experimental Hall. In this contribution, we will present the new layout of the FLASH facility and the first results to operate it with different parameter sets. We will show present results achieved during the commissioning of the new beamline. Finally, we will give an outlook of further commissioning plans and user operation. S. Ackermann for the FLASH II Team
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MOPF28	Beam Diagnostics and Timing Monitoring for SuperKEKB Injector Linac	linac, timing, positron, target	110
	F. Miyahara, K. Furukawa, R. Ichimiya, N. Iida, M. Ikeno, H. Kaji, M. Satoh, M. Shoji, T. Suwada, M. Tanaka, Y. Yano KEK, Ibaraki, Japan T. Okazaki EJIT, Hitachi, Ibaraki, Japan
	The SuperKEKB injector linac has multiple operation modes for the electron beam injection into 3 separate rings, SuperKEKB HER, PF (Photon Factory) Ring and PF-AR, and the positron beam injection into the damping ring and the SuperKEKB LER. The operation modes can be switched every 20 milli-second with arbitrary order. The beam parameters such as charge, energy and emittance are different for each of the rings. Moreover, the bunch charge of the electron beam, 5nC, is 5 times higher and the emittance of ~10 mm•mrad is 30 times lower than those of the KEKB injector. Thus, development of BPM readout system with a wide dynamic range and installation of optical fiber detector with a good S/N ratio for the wire scanners and bunch-length monitor have been performed. For stable operation of the linac, many timing signals have to be monitored as well. To that end we have developed 32-bit multi-hit time-to-digital converters (TDCs) with 1-ns resolution. The first beam tests of those systems are reported in this paper.
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MOPF31	Overview of Beam Instrumentation Activities for SwissFEL	radiation, vacuum, undulator, pick-up	119
	R. Ischebeck, R. Abela, F. Ardana-Lamas, V.R. Arsov, R. Baldinger, H.-H. Braun, M. Calvi, R. Ditter, C. Erny, F. Frei, R. Ganter, I. Gorgisyan, C.P. Hauri, S. Hunziker, P.N. Juranic, B. Keil, W. Koprek, R. Kramert, D. Llorente Sancho, F. Löhl, F. Marcellini, G. Marinkovic, B. Monoszlai, G.L. Orlandi, C. Ozkan, L. Patthey, M. Pedrozzi, P. Pollet, M. Radovic, L. Rivkin, M. Roggli, M. Rohrer, V. Schlott, A.G. Stepanov, J. Stettler PSI, Villigen PSI, Switzerland F. Ardana-Lamas, I. Gorgisyan, C.P. Hauri, L. Rivkin EPFL, Lausanne, Switzerland P. Peier DESY, Hamburg, Germany
	SwissFEL will provide users with brilliant X-ray pulses in 2017. A comprehensive suite of diagnostics is needed for the initial commissioning, for changes to the operating point, and for feedbacks. The development of instrumentation for SwissFEL is well underway, and solutions have been identified for most diagnostics systems. I will present here an overview of the instrumentation for SwissFEL, and give details on some recent developments.
	Poster MOPF31 [4.418 MB]
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MOPD02	The Electron Backscattering Detector (eBSD), a New Tool for the Precise Mutual Alignment of the Electron and Ion Beams in Electron Lenses	ion, proton, detector, scattering	129
	P. Thieberger, Z. Altinbas, C. Carlson, C. Chasman, M.R. Costanzo, C. Degen, K.A. Drees, W. Fischer, D.M. Gassner, X. Gu, K. Hamdi, J. Hock, Y. Luo, A. Marusic, T.A. Miller, M.G. Minty, C. Montag, A.I. Pikin, S.M. White 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 The Relativistic Heavy Ion Collider (RHIC) electron lenses, being commissioned to attain higher polarized proton-proton luminosities by partially compensating the beam-beam effect, require good alignment of the electron and proton beams. These beams propagating in opposite directions in a 5T solenoid have a typical rms width of 300 microns and need to overlap each other over an interaction length of about 2 m with deviations of less than ~50 microns. A new beam diagnostic tool to achieve and maintain this alignment is based on detecting electrons that are backscattered in close encounters with protons. Maximizing the intensity of these electrons ensures optimum beam overlap. The successful commissioning of these devices using 100 GeV/amu gold beams is described. Future developments are discussed that will further improve the sensitivity to small angular deviations.
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MOPD03	Performance and Upgrade of the Fast Beam Condition Monitor at CMS	luminosity, background, electronics, laser	134
	M. Hempel, H.M. Henschel, O. Karacheban, W. Lange, J.L. Leonard, M. Penno DESY Zeuthen, Zeuthen, Germany K. Afanaciev NC PHEP BSU, Minsk, Belarus A.I. Bell DLS, Oxfordshire, United Kingdom P.R. Burtowy, A.E. Dabrowski, R. Loos, V. Ryjov, A.A. Zagozdzinska CERN, Geneva, Switzerland W. Lohmann BTU, Cottbus, Germany W. Lohmann, R. Walsh DESY, Hamburg, Germany B.L. Pollack NU, Evanston, Illinois, USA D. Przyborowski AGH, Cracow, Poland S. Schuwalow Uni HH, Hamburg, Germany D.P. Stickland PU, Princeton, New Jersey, USA
	The Fast Beam Condition Monitor BCM1F is a diamond based particle detector inside CMS. It is based on 8 single crystal CVD diamond sensors on both ends of the interaction point and is used for beam background and luminosity measurements. The system has been operated up to an integrated luminosity of 30fb-1, corresponding to a particle fluence of 8.78·10¹³ cm^-2 (24GeV proton equivalent). To maintain the performance at a bunch spacing of 25ns and at the enhanced luminosity after the LHC Long Shutdown LS1, an upgrade of BCM1F is necessary. The upgraded system features 24 single crystal diamond sensors with a two pad metallization, a very fast front-end ASIC built with 130nm CMOS technology and new back-end electronics. A prototype of the upgraded BCM1F components were studied in the 5GeV electron beam at DESY. Measurements were done on the signal shape as function of time, the collection efficiency as a function of voltage and position of the impact point on the sensor surface. The preliminary results of this testbeam will be presented. In addition, the status of the new upgraded BCM1F will be given.
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MOPD05	Dual Transverse and Longitudinal Streak Camera Imaging at ELSA	damping, cavity, diagnostics, synchrotron	144
	M.T. Switka, F. Frommberger, P. Hänisch, W. Hillert, M. Schedler ELSA, Bonn, Germany
	Funding: Funded by the German Research Foundation (DFG) within Colaborative Research Center (SFB/TRR) 16 The electron pulse stretcher ring ELSA located at Bonn University provides 0.5 – 3.5 GeV polarized and non-polarized electron beams for external experimental stations. A streak camera system has been installed to capture time resolved images of beam dynamics ranging from nanoseconds to several milliseconds. Particular attention was drawn to the capability of simultaneous imaging of both transverse beam dimensions, hence providing information of all spatial dimensions in one synchroscan or slow sweep measurement. Incoherent and coherent beam instabilities, especially at high stored beam currents, are subject of analysis due to the planned intensity upgrade towards 200 mA for standard operation. The current resolution performance of the imaging system and machine relevant measurements are presented.
	Poster MOPD05 [6.133 MB]
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MOPD06	Electron Beam Diagnostics for Short Pulse FEL Schemes at CLARA	laser, FEL, diagnostics, simulation	147
	S. Spampinati, D. Newton Cockcroft Institute, Warrington, Cheshire, United Kingdom D. Newton The University of Liverpool, Liverpool, United Kingdom
	CLARA (Compact Linear Accelerator for Research and Applications) [1] is a proposed 250 MeV, 100-400 nm FEL test facility at Daresbury Laboratory. The purpose of CLARA is to test and validate new FEL schemes in areas such as ultra-short pulse generation, temporal coherence and pulse-tailoring. Some of the schemes that can be tested at CLARA depend on a manipulation of the electron beam properties with characteristic scales shorter than the electron beam and require a 30 - 50 μm modulation of the beam energy acquired via the interaction with an infrared laser beam in a short undulator. In this article we describe the electron beam diagnostics required to carry on these experiments.
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MOPD08	A Double-Prism Spectrometer for the Longitudinal Diagnosis of Femtosecond Electron Bunches with Mid-Infrared Transition Radiation	radiation, detector, diagnostics, FEL	157
	S. Wunderlich, E. Hass, B. Schmidt, M. Yan DESY, Hamburg, Germany
	Funding: The project has been supported by the BMBF under contract 05K10GU2 & FS FLASH 301. Electron bunch lengths in the sub-10 fs regime and charges of a few tens of picocoulombs are parameters required for free-electron lasers [] and are also a consequence from the intrinsic process in laser-driven plasma wake field acceleration []. Since the coherent spectrum of transition radiation of these bunches carries the information on the longitudinal bunch profile in the form factor, the spectroscopy of transition radiation is an attractive method to determine the electron bunch length. A double-prism spectrometer has been developed and demonstrated for the single-stage measurement of mid-infrared transition radiation between 2 μm and 18 μm. The spectrometer facilitates single-shot spectral measurements with high signal-to-noise ratio utilising a line array of mercury cadmium telluride detectors. In this contribution, we present the spectrometer and measurements of electron bunches of the Free-Electron Laser in Hamburg (FLASH) at DESY. The results are compared to established bunch length monitors which are a multi-stage grating spectrometer for transition radiation and a transverse deflecting structure accessing the longitudinal phase space of the electron bunches directly. J. Rönsch-Schulenburg et al., Proceedings of FEL 2014, TUB04 (2014), to be published **O. Lundh et al., Nature Physics 7, 219–222 (2011)
	Poster MOPD08 [1.346 MB]
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MOPD09	Longitudinal Phase Space Tomography Using a Booster Cavity at the Photo Injector Test Facility at DESY, Zeuthen Site (PITZ)	laser, booster, acceleration, gun	161
	D. Malyutin, M. Groß, I.I. Isaev, M. Khojoyan, G. Kourkafas, M. Krasilnikov, B. Marchetti, F. Stephan, G. Vashchenko DESY Zeuthen, Zeuthen, Germany
	One of the ways to measure the longitudinal phase space of the electron bunch in a linear accelerator is a tomographic technique based on measurements of the bunch momentum spectra while varying the bunch energy chirp. The energy chirp at PITZ can be controlled by varying the RF phase of the CDS booster – the accelerating structure installed downstream the electron source (RF gun). The resulting momentum distribution can be measured with a dipole spectrometer downstream. As a result, the longitudinal phase space at the entrance of the CDS booster can be reconstructed. In this paper the tomographic technique for longitudinal phase space measurements is described. Results of measurements at PITZ are presented and discussed.
	Poster MOPD09 [0.925 MB]
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MOPD10	New Results Of FERMI FEL1 EOS Diagnostics With Full Optical Synchronization	laser, FEL, diagnostics, electronics	165
	M. Veronese, E. Allaria, P. Cinquegrana, E. Ferrari, F. Rossi, P. Sigalotti, C. Spezzani Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy E. Ferrari Università degli Studi di Trieste, Trieste, Italy
	The Electro Optical Sampling diagnostics (EOS) of the FERMI FEL has been recently upgraded with a full optical synchronization of its dedicated femtosecond fiber laser to the ultra-stable optical pulsed timing system of FERMI. For this purpose a dual synchronization electronics has been developed and installed. It exploits a mixed error signal derived from both optical to electrical conversion and from a second harmonic generation based optical phase detection. For this second part a new optical setup including a cross correlator has been installed. The operation of the EOS has greatly benefited from the upgrade. The arrival time measurements have been compared with the ones from the bunch arrival monitor diagnostics (BAM) showing very good agreement. This new setup has also allowed to improve the bunch profile measurement. Some examples of measurement with ZnTe and GaP are presented. Finally, usability and operator friendliness of the new setup are also discussed.
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MOPD12	Novel Femtosecond Level Synchronization of Titanium Sapphire Laser and Relativistic Electron Beams	laser, polarization, plasma, timing	174
	M. Titberidze, F.J. Grüner, A.R. Maier Uni HH, Hamburg, Germany M. Felber, K. Flöttmann, T. Lamb, H. Schlarb, C. Sydlo DESY, Hamburg, Germany F.J. Grüner, A.R. Maier, B. Zeitler CFEL, Hamburg, Germany E. Janas Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
	Laser driven plasma accelerators are offering high gradient (~ 10-100GV/m), high quality (low emittance, short bunch length) electron beams which can be suitable for future compact, bright and tunable light sources. In the framework of the Laboratory for Laser- and beam-driven plasma Acceleration (LAOLA) collaboration at Deutsches Elektronen-Synchrotron (DESY) the external injection experiment for injecting electron bunches from a conventional RF accelerator into the linear plasma wave is in progress. External injection experiments at REGAE (Relativistic Electron gun for Atomic Exploration) require sub-10 fs precision synchronization of laser and electron beams in order to perform a beam scan into the plasma wave by varying the delay between electron beam and laser pulses. In this paper we present a novel optical to microwave synchronization scheme, based on a balanced single output integrated Mach-Zehnder Modulator (MZM). The scheme offers a highly sensitive phase detector between a pulsed 800 nm Ti:Sa laser and a 3GHz microwave reference source. It is virtually independent of input laser power fluctuation and it offers femtosecond long-term precision. Together with the principal of operation of this setup, we will present promising preliminary experimental results of the detector stability.
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MOPD15	CW Beam Stability Analysis in Time and Frequency Domain	diagnostics, high-voltage, radiation, laser	179
	M. Kuntzsch, M. Gensch, B.W. Green, S. Kovalev, U. Lehnert, P. Michel, R. Schurig, J. Teichert HZDR, Dresden, Germany
	The superconducting quasi CW Linac ELBE has been characterized in terms of energy and timing stability. The measurement results presented show a combination of a laser-based bunch arrival-time measurements (BAM), a fast beam position monitor (BPM) readout with single bunch resolution and a compression monitor (BCM) based on a fast pyro-electric detector. By changing the bunch compression factor a separation and identification of jitter sources has been achieved. The quasi CW mode of operation enables frequency domain data analysis with high dynamic range, which gives a better understanding of the main sources of jitter. Experimental results for both injectors (thermionic DC, superconducting RF) are presented.
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MOPD17	Single-Shot Electro-Optical Diagnostics at the ANKA Storage Ring	laser, storage-ring, wakefield, operation	182
	N. Hiller, A. Borysenko, E. Hertle, V. Judin, B. Kehrer, A.-S. Müller, M.J. Nasse, M. Schuh, P. Schönfeldt, N.J. Smale, J.L. Steinmann KIT, Karlsruhe, Germany P. Peier, B. Steffen DESY, Hamburg, Germany V. Schlott PSI, Villigen PSI, Switzerland
	Funding: This work is funded by the BMBF contract numbers: 05K10VKC, 05K13VKA. ANKA is the first storage ring in the world with a near-field single-shot electro-optical (EO) bunch profile monitor. The method of electro-optical spectral decoding (EOSD) uses the Pockels effect to modulate the longitudinal electron bunch profile onto a long, chirped laser pulse passing through an EO crystal. The laser pulse is then analyzed with a single-shot spectrometer and from the spectral modulation, the temporal distribution can be extracted. The setup is tuned to a sub-ps resolution (granularity) and can measure down to bunch lengths of 1.5 ps RMS for bunch charges as low as 30 pC. With this setup it is possible to study longitudinal beam dynamics (e. g. microbunching) occurring during ANKA's low-alpha-operation, an operation mode with longitudinally compressed bunches to generate coherent synchrotron radiation in the THz range. In addition to measuring the longitudinal bunch profile, long-ranging wake-fields trailing the electron bunch can also be studied, hinting bunch-bunch interactions.
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MOPD24	Diagnostics of and with Laser-Induced Energy Modulation at the DELTA Storage Ring	laser, radiation, undulator, storage-ring	202
	S. Khan, S. Hilbrich, H. Huck, M. Huck, M. Höner, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, P. Ungelenk DELTA, Dortmund, Germany
	Funding: This work is supported by the BMBF (05K13PEC) and DFG (INST212/236-1) and by the Land NRW. DELTA is a 1.5-GeV electron storage ring operated by the Center for Synchrotron Radiation at the TU Dortmund University. An interaction between electron bunches and femtosecond laser pulses is routinely used to generate ultrashort pulses of coherent synchrotron radiation at harmonics of the laser wavelength (coherent harmonic generation, CHG) as well as short and coherent pulses in the THz regime. The paper describes diagnostics methods to optimize the laser-electron overlap and to characterize the generated VUV and THz pulses. Furthermore, the laser-electron interaction can be employed as a beam diagnostics tool, e.g. to study the longitudinal steady-state bunch profile as well as dynamic properties during RF-phase modulation, which is applied to improve the beam lifetime.
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MOPD25	Time Domain Pickup Signal characterization for Low Charge Arrival-Time Measurements at FLASH	pick-up, simulation, laser, operation	209
	A. Angelovski, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany M.K. Czwalinna, H. Schlarb, C. Sydlo DESY, Hamburg, Germany T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	For the low charge operation mode at the European XFEL, high bandwidth cone-shaped pickups were developed as a part of the Bunch Arrival-time Monitors (BAMs). The simulation showed that the signal parameters of interest, the signal slope and bandwidth are improved by more than a factor of six compared to the state of the art pickups. The pickups are installed at FLASH for verification. In this paper, time-domain measurements of the cone-shaped pickups at FLASH are presented. The pickup signal is recorded with a high bandwidth sampling oscilloscope. Two channel measurements are conducted with a single and a combined pickup signal in order to analyze the orbit and charge dependence of the pickup signal parameters. The measured time domain pickup signal wave form is compared to the CST PARTICLE STUDIO simulation.
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TUIXB1	The Beam Instrumentation and Diagnostic Challenges for LHC Operation at High Energy	detector, synchrotron, emittance, quadrupole	216
	O.R. Jones CERN, Geneva, Switzerland
	This contribution will present the role of beam instrumentation and diagnostics in facing the challenges posed by running the LHC close to its design energy of 7TeV. Machine protection will be ever more critical, with the quench level of the magnets significantly reduced, so relying heavily on the beam loss system and abort gap monitor interlocks on the beam position and fast beam current change system. Non-invasive profile monitoring also becomes more of a challenge, with standard synchrotron light imaging limited by diffraction and rest gas ionisation monitoring dominated by space charge effects. There is also a requirement to better understand beam instabilities, of which several were observed during Run I, leading to the need for synchronised bunch-by-bunch, turn-by-turn information from many distributed instrumentation systems. All of these challenges will be discussed along with the strategies adopted to overcome them.
	Slides TUIXB1 [7.329 MB]
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TUCYB2	Pulsed Green Laser Wire System for Effective Inverse Compton Scattering	laser, cavity, emittance, experiment	254
	A.A. Rawankar, N. Terunuma, J. Urakawa Sokendai, Ibaraki, Japan T. Akagi, A.S. Aryshev, Y. Honda, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan D. Jehanno LAL, Orsay, France K. Sakaue Waseda University, Tokyo, Japan
	Funding: This work has been supported by the Quantum Beam Technology Program of the Japanese Ministry of Education, Culture, Sports, Science,and Technology(MEXT). Laser-Compton scattering has become an important technique for beam diagnostics of the latest accelerators. In order to develop technologies for low emittance beams, an Accelerator Test facility (ATF) was built at KEK. It consists of an electron linac, a damping ring in which beam emittance is reduced, and an extraction line. For emittance measurement we are developing a new type of beam profile monitor which works on the principle of inverse Compton scattering between electron and laser light. In order to achieve effective collision of photon and electron, a pulsed and very thin size laser is required. Laser wire is one technique of measuring a small beam size. With green lasers, which are converted to second harmonics from IR pulsed laser, minimum beam waist is half of the beam waist obtained using infrared (IR) laser oscillator. Therefore, it is possible to obtain beam waist less than 5 μm using green laser pulse, which is required for effective photon-electron collision. First, pulsed IR seed laser is amplified with 1.5 meter long PCF based amplifier system. This pulsed IR laser is converted to second harmonics with a non-linear crystal. Pulsed green laser is injected inside four mirror optical cavity to obtain very small beam waist at interaction point (IP). Using a pulsed compact laser wire, we can measure 10 um electron beams in vertical directions. We report the development of the pulsed green laser and parameters of compact four mirror optical cavity for effective inverse Compton scattering.
	Slides TUCYB2 [2.632 MB]
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TUCYB3	SwissFEL Beam Profile Monitor	radiation, vacuum, laser, detector	259
	R. Ischebeck, E. Prat, V. Schlott, V.G. Thominet PSI, Villigen PSI, Switzerland P. Krejcik, H. Loos SLAC, Menlo Park, California, USA M. Yan DESY, Hamburg, Germany
	We have developed a beam profile monitor that allows us to measure two-dimensional electron beam profiles for highly compressed electron bunches. Such bunches have plagued profile measurements in optical transition radiation monitors in the past, because coherent radiation entering the optical system has invalidated the images and even destroyed cameras. The present design makes use of a scintillating crystal, and directs coherent transition radiation away from the optical axis by careful choice of the angle. When observing Snell's law of refraction as well as the Scheimpflug imaging condition, a resolution better than the thickness of the scintillator can be achieved. We will present measurements performed at the SwissFEL Injector Test Facility and at the Linac Coherent Light Source. The high resolution and excellent sensitivity of this monitor make it ideal for installation in SwissFEL.
	Slides TUCYB3 [42.624 MB]
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TUIZB1	Radiation Sources and Their Application for Beam Profile Diagnostics	radiation, photon, diagnostics, optics	263
	G. Kube DESY, Hamburg, Germany
	Radiation generated by high-energy particle beams is widely used for beam diagnostic purposes. Depending on the mechanism of radiation generation, the emitted wavelength range extends from the THz up to the X-ray region, thus allowing the measurement of beam profiles in the longitudinal and the transverse plane over a wide range. In this talk, basic considerations for radiation based profile measurements will be discussed with special emphasis on the mechanism of radiation generation and the impact on beam diagnostic measurements.
	Slides TUIZB1 [4.803 MB]
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TUCZB1	Novel Emittance Diagnostics for Diffraction Limited Light Sources Based on X-ray Fresnel Diffractometry	emittance, radiation, diagnostics, betatron	274
	M. Masaki, Y. Shimosaki, S. Takano, M. Takao JASRI/SPring-8, Hyogo-ken, Japan
	A novel emittance diagnostics technique with high sensitivity using X-ray Fresnel diffraction by a single slit has been developed to measure micron-order electron beam sizes at insertion devices (IDs) of photon beamlines. The X-ray Fresnel diffractometry (XFD)* is promising for diagnostics especially of a so-called diffraction limited storage ring (DLSR) with ultra-low emittance. In the DLSR, due to inevitable field errors of strong quadrupole and sextupole magnets, unwanted distortion of lattice functions and local betatron coupling will result in a different light source size at each beamline. Therefore, measurements of electron beam sizes at the ID source points will be essential to ensure the absence of degradation of brilliance and transverse coherence of radiation at the beamlines. The XFD observes a double-lobed diffraction pattern that emerges by optimizing the single slit width. The principle is based on a correlation between the depth of a median dip in the double-lobed pattern and the light source size at the ID. The validity of the new technique was theoretically and experimentally studied. The achievable resolution of the XFD will be also discussed. * M. Masaki, et al.,"X-ray Fresnel Diffractometry for Ultra-Low Emittance Diagnostics of Next Generation Synchrotron Light Sources", submitted to Phys. Rev.ST-AB.
	Slides TUCZB1 [5.456 MB]
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TUCZB2	Measurements of Small Vertical Beamsize using a Coded Aperture at Diamond Light Source	radiation, detector, synchrotron, synchrotron-radiation	279
	C. Bloomer, G. Rehm DLS, Oxfordshire, United Kingdom J.W. Flanagan KEK, Ibaraki, Japan
	Diamond Light Source produces a low emittance 3GeV electron beam which is now regularly operated at 8pm.rad vertical emittance. This corresponds to a vertical beamsize of just 13um in the dipole, which is at a high vertical beta location and routinely used for observing the synchrotron radiation using a pinhole camera. Deconvolution of the images from the pinhole camera to maximise resolution is limited by uncertainly regarding the precise shape of the pinhole, resulting in uncertainty on its computed point spread function. Recently a coded aperture has been installed which offers the potential to improve upon the traditional pinhole measurement by offering both higher resolution and increased flux seen through a larger total aperture, however, at the cost of significantly more complex analysis of the recorded images. A comparison of results obtained using the coded aperture and those achieved using the conventional pinhole is presented.
	Slides TUCZB2 [4.199 MB]
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TUCZB3	A Quantum Gas Jet for Non-Invasive Beam Profile Measurement	ion, focusing, photon, vacuum	284
	A. Jeff, E.B. Holzer, T. Lefèvre CERN, Geneva, Switzerland A. Jeff, V. Tzoganis, C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom V. Tzoganis, C.P. Welsch, H.D. Zhang Cockcroft Institute, Warrington, Cheshire, United Kingdom
	A novel instrument for accelerator beam diagnostics is being developed by using De Broglie-wave focusing to create an ultra-thin neutral gas jet. Scanning the gas jet across a particle beam while measuring the interaction products, the beam profile can be measured. Such a jet scanner will provide an invaluable diagnostic tool in beams which are too intense for the use of wire scanners, such as the proposed CLIC Drive Beam. In order to create a sufficiently thin jet, a focusing element working on the DeBroglie wavelength of the Helium atom has been designed. Following the principles of the Photon Sieve, we have constructed an Atomic Sieve consisting of 5230 nano-holes etched into a thin film of silicon nitride. When a quasi-monochromatic Helium jet is incident on the sieve, an interference pattern with a single central maximum is created. The stream of Helium atoms passing through this central maximum is much narrower than a conventional gas jet. The first experiences with this device are presented here, along with plans for further tests.
	Slides TUCZB3 [13.880 MB]
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TUPF02	Proposed Pulse Stretching of BPM Signals for the Position Determination of Very Short and Closely Spaced Bunches	simulation, synchrotron-radiation, collider, synchrotron	294
	P. Thieberger, S.J. Brooks, K. Hamdi, R.L. Hulsart, G.J. Mahler, R.J. Michnoff, M.G. Minty, D. Trbojevic 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 A proposal for a future ultra relativistic polarized electron-proton collider (eRHIC) is based in part on the transport of multiple electron beams of different energies through two FFAG beam transports around the 3834 m long RHIC tunnel circumference in order to recirculate them through an Energy Recovery Linac for their stepwise acceleration and deceleration. For each of these transports, the beams will travel in a common vacuum chamber, horizontally separated from each other by a few mm. Determining the position of the individual bunches is challenging due to their very short length (~12 ps rms) and their temporal proximity (less than 4 ns in some cases). Providing pulses adequate for accurate sampling is further complicated by the less-than-ideal response of long coaxial cables. Here we propose two approaches to produce enhanced, i.e. stretched pulse shapes of limited duration; one based on specially shaped BPM electrodes and the other one on analog integration of more conventional stripline BPM signals. In both cases, signals can be generated which contain relatively flat portions which should be easier to sample with good precision without requiring picoseconds timing accuracy.
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TUPF08	Design, Development and Commissioning of a MTCA-Based Button and Strip-Line BPM System for FLASH2	electronics, timing, operation, undulator	320
	B. Lorbeer, N. Baboi, L.P. Petrosyan, F. Schmidt-Föhre DESY, Hamburg, Germany
	The FLASH (Free Electron Laser in Hamburg) facility at DESY (Deutsches Elektronen-Synchrotron) in Germany has been extended by a new undulator line called FLASH2 to provide twice as many experimental stations for users in the future. After the acceleration of the electron bunch train up to 1.2GeV, a part can be kicked into FLASH2, while the other is going to the old undulator line. In order to tune the wavelength of the SASE (Self Amplified Spontaneous Emission), the new line is equipped with variable gap undulators. The commissioning phase of FLASH2 started in early 2014 and is planned to be continued parasitically during user operation in FLASH1. One key point during first beam commissioning is the availability of standard diagnostic devices such as BPM (Beam Position Monitor). In this paper we present the design and first operational experience of a new BPM system for button and strip-line monitors based on MTCA.4. This is referred to as LCBPM (low charge BPM) in contrast to the old systems at FLASH initially designed for bunch charges of 1nC and higher. We summarize the recent analog and digital hardware development progress[,***] and first commissioning experience of this new BPM system at FLASH2 and present a first estimation of its resolution in a large charge range from 1nC down to 100pC and smaller. flash2.desy.de B. Lorbeer et.al.,TUPA19, IBIC2012 * MTCA.4 (Micro Telecommunications Computing Architecture ) for physics **** Frank Schmidt-Foehre et.al.,IPAC2014 Dresden
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TUPF09	Calibration of OLYMPUS/DORIS Beam Position Monitors	electronics, experiment, positron, target	324
	U. Schneekloth, N. Görrissen, G. Kube, J. Neugebauer, Ru. Neumann, F. Schmidt-Föhre DESY, Hamburg, Germany
	The goal of the OLYMPUS experiment is a precise measurement of the ratio of the positron-proton and electron-proton elastic scattering cross sections in order to quantify the effect of two-photon exchange. The experiment was performed using intense beams of electrons and positrons stored in the DORIS ring at Deutsches Elektronen Synchrotron in Hamburg, impinging on an un-polarized, internal, hydrogen gas target. An essential ingredient of the experiment is a precise determination of the luminosity, which requires a precise knowledge of the beam position of both beam species. During DORIS operation cylindrical button beam position monitors, read out by two independent electronics systems, were mounted up- and downstream of the target chamber. After the end of operation, the readout systems were cross-calibrated. The BPMs were then calibrated using a test-stand, consisting of a wire scanner assembly. The beam was simulated by applying an RF signal to the wire. This paper describes the calibration principles and test setup, together with the results compared to the expected BPM response.
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TUPF13	Diamond-Based Photon BPMs for Fast Electron-Beam Diagnostics in Synchrotron Radiation Sources	photon, radiation, diagnostics, detector	342
	M. Antonelli, G. Cautero, D. Giuressi, S. Lizzit, R.H. Menk Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy A. De Sio, E. Pace Università degli Studi di Firenze, Firenze, Italy M. Di Fraia Università degli Studi di Trieste, Trieste, Italy
	Electron-beam stability is amongst the primary concerns in current Synchrotron Radiation (SR) sources; in particular, in third-generation SR facilities high-brightness beamlines using undulator radiation are extremely sensitive to electron-beam oscillations. Orbit stabilization has been intensively addressed in the past years and many SR machines have been equipped with a Fast Orbit Feedback (FOFB) based on electron Beam-Position Monitors (eBPMs). On the other hand, photon Beam-Position Monitors (pBPMs), besides providing beamline users with crucial calibration data, are also a useful tool for keeping the electron beam under control, by monitoring position and intensity of the delivered radiation. The machine control system can take advantage of this information in order to improve the stability of the electron-beam. A diagnostic beamline, utilizing a couple of fast pBPMs based on single-crystal CVD diamond detectors, has been built and inserted into the central dead-end outlet of one of Elettra’s bending-magnets. Tests have been carried out both during normal machine operations and by deliberately moving the orbit during dedicated shifts. Owing to the outstanding properties of diamond in terms of speed and radiation hardness, the results show how the aforementioned system allows the beam position to be monitored with sub-micrometric precision at the demanding readout rates required by the FOFB. The radiation hardness of the sensors allows the operation over extended periods of time without special maintenance. Therefore, this system is particularly suited for storage-ring sections lacking in electron-beam monitoring and the tested diagnostic line represents a demonstrator for future implementation of pBPMs at several bending-magnet front ends of Elettra.
	Poster TUPF13 [3.409 MB]
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TUPF18	Development of a Button BPM for the LCLS-II project	diagnostics, wakefield, feedback, HOM	361
	A. Lunin, T.N. Khabiboulline, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	A high sensitivity button BPM is under development for a linac section of the LCLS-II project. Since the LCLS-II linac will operate with bunch charge as low as 10 pC, we analyse various options for pickup button and feedthrough in order to maximize the BPM output signal at low charge regime. As a result the conceptual BPM design is proposed including an analytical estimation of the BPM performance as well as numerical simulation with CST Particle Studio and ANSYS HFSS. Both numerical methods show a good agreement of BPM output signals for various design parameters. Finally we describe the signal processing scheme and the electronics we are going to use.
	Poster TUPF18 [0.846 MB]
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TUPF25	Characterization of the Laser Beam for HHG Seeding	FEL, simulation, laser, undulator	380
	S. Ackermann, B. Faatz DESY, Hamburg, Germany V. Miltchev Uni HH, Hamburg, Germany
	Recently free-electron laser (FEL) facilities around the world have shown that the direct seeding approach can enhance the spectral, temporal and coherence properties of the emitted radiation as well as reducing the fluctuations in arrival time and output energy. To achieve this, a photon pulse of the desired wavelength ("seed") is overlapped transversely and temporally with the electrons in the undulator to start up the FEL process from a defined radiation pulse rather than from noise. To benefit from the advantages of this technique, the energy of the seed has to exceed the energy of the spontaneous emission. The ratio between these two energies is strongly influenced by the seed beam properties. In this contribution, we will present simulations on the achieveable power contrast in dependence on the beam quality of the seed, and compare the results to the experimental data of the seeded FEL experiment ("sFLASH") at DESY, Hamburg. Additionally we show up a way of creating FEL seed pulses for simulation purposes from Hermite-Gaussian generating functions.
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TUPF26	Linear Focal Cherenkov-Ring Camera for Single Shot Observation of Longitudinal Phase Space Distribution for Non-Relativistic Electron Beam	vacuum, laser, gun, photon	385
	K. Nanbu, H. Hama, F. Hinode, S. Kashiwagi, A. Lueangaramwong, T. Muto, I. Nagasawa, S. Nagasawa, Y. Shibasaki, K. Takahashi, C. Tokoku Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	A test accelerator for the coherent THz source (t-ACTS) has been constructed at Tohoku University, in which the generation of intense coherent THz radiation from sub-picosecond electron bunches will be demonstrated. The final electron bunch length of accelerated beam is mostly dictated by the longitudinal phase space distribution at the exit of electron-gun. Therefore, measurement of Initial electron distribution in the longitudinal phase space produced by an electron gun is crucial for stable production of very short electron bunches, However, measurement of the longitudinal phase space of a relatively lower energy electron beam is especially difficult because space charge effects in drift spaces for measurement system might be strong. A method for measurement of electron energy (or momentum) applying velocity dependence of the opening angle of Cherenkov radiation in the radiator has been proposed for relatively lower energy electrons. Combined use of a streak camera and the “turtle-back” mirror that confines the Cherenkov light onto a linear focal line may allow us to observe the longitudinal phase space distribution directly. Current status of the system development will be reported in this conference.
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TUPD02	Electron Beam Profiler for the Fermilab Main Injector	proton, gun, simulation, ion	398
	R.M. Thurman-Keup, M.L. Alvarez, J. Fitzgerald, C.E. Lundberg, P.S. Prieto Fermilab, Batavia, Illinois, USA W. Blokland ORNL, Oak Ridge, Tennessee, USA
	The long range plan for Fermilab calls for large proton beam intensities in excess of 2 MW for use in the neutrino program. Measuring the transverse profiles of these high intensity beams is challenging and generally relies on non-invasive techniques. One such technique involves measuring the deflection of a beam of electrons with a trajectory perpendicular to the proton beam. A device such as this is already in use at the Spallation Neutron Source at ORNL and a similar device will be installed shortly in the Fermilab Main Injector. The Main Injector device is discussed in detail and some test results and simulations are shown.
	Poster TUPD02 [2.115 MB]
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TUPD04	Third Generation Residual Gas Ionization Profile Monitors at Fermilab.	controls, detector, proton, ion	408
	J.R. Zagel, M.L. Alvarez, B.J. Fellenz, C.C. Jensen, C.E. Lundberg, E.S.M. McCrory, D. Slimmer, R.M. Thurman-Keup, D.G. Tinsley Fermilab, Batavia, Illinois, USA
	Funding: DOE The latest generation of IPM's installed in the Fermilab Main Injector and Recycler incorporate a 1 kG permanent magnet, a newly designed high-gain, rad-tolerant preamp, and a control grid to moderate the charge that is allowed to arrive on the anode pick-up strips. The control grid is intended to select a single Booster batch measurement per turn. Initially it is being used to allow for a faster turn-on of a single, high-intensity cycle in either machine. The expectation is that this will extend the Micro Channel Plate lifetime, which is the high-cost consumable in the measurement system. We discuss the new design and data acquired with this system.
	Poster TUPD04 [11.950 MB]
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TUPD07	Performance Demonstration of the Non-Invasive Bunch Shape Monitor at GSI High Current LINAC	background, linac, ion, detector	421
	B. Zwicker, O.K. Kester IAP, Frankfurt am Main, Germany C. Dorn, P. Forck, O.K. Kester, P. Kowina, B. Zwicker GSI, Darmstadt, Germany
	Funding: Supported by EU-Project CRISP, WP3 T1 ‘Non-intercepting Bunch Shape Monitors‘ At the heavy ion LINAC at GSI, a novel scheme of non-invasive Bunch Shape Monitor has been tested with several ions beam at 11.4 MeV/u and beam current in the range from 80 μA to 1000 μA. Caused by the beam impact on the residual gas, secondary electrons are liberated. These electrons are accelerated by an electrostatic field, transported through a sophisticated electrostatic energy analyzer and an rf-deflector, acting as a time-to-space converter. Finally a MCP amplifies the electrons and the electron distribution is detected by a CCD camera. For the applied beam settings this Bunch Shape Monitor is able to obtain longitudinal profiles down to of 250 ps RMS width with an RMS resolution of 34 ps, corresponding to 0.5° of the 36 MHz acceleration frequency. Systematic parameter studies, for the device were performed to demonstrate the applicability and to determine the achievable resolution. The background contribution, as orginated by x-rays, are investigated.
	Poster TUPD07 [4.425 MB]
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TUPD09	Vacuum Improvement of Bunch Shape Monitor for J-PARC Linac	vacuum, target, high-voltage, linac	430
	A. Miura, Y. Kawane, N. Ouchi JAEA/J-PARC, Tokai-mura, Japan T. Miyao KEK, Ibaraki, Japan
	During the shutdown in summer 2012, we installed three BSMs (Bunch Shape Monitors) at the upstream of the ACS (Annular Coupled Structure Linac) section in order to perform longitudinal matching. ACS cavities were installed in summer 2013 to upgrade the Linac energy from 181 MeV to 400 MeV. Prior to the ACS installation, BSMs were installed and the beam commissioning of the BSMs has been conducted after the summer shutdown in 2012. During the BSM measurements, a problem of the degradation in vacuum conditions was found. One reason for this problem is the dark current resulting in the desorption of absorbed gas molecules. And another reason is the outgas released from materials when the high voltage and RF power are supplied for the electro-static lens and RF deflector, respectively. In order to solve this problem, BSMs were dismounted from the beam line and the off-line baking operations with outgas analysis had been performed to avoid the degradation of the vacuum. As the result of the gas analysis, we found that the outgas contains some heavy hydrocarbons. After these heavy hydrocarbon gaseous were removed and the vacuum level improved for about one order, we completed off-line baking. We will install all three BSMs in at the upstream of the ACS again with the additional vacuum pumps. This paper describes the vacuum degradation of the BSMs, how to conduct the baking operation for BSMs and its results. The improved set-ups of the vacuum are also introduced.
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TUPD11	LANSCE 1L Harp Data Acquisition System Upgrade	data-acquisition, FPGA, software, hardware	438
	J.D. Sedillo, J.D. Gilpatrick, J.D. Nguyen LANL, Los Alamos, New Mexico, USA M.E. Gruchalla URS, Albuquerque, New Mexico, USA
	The 1L harp is the last beam diagnostic preceding LANSCE’s 1L Target, the neutron source of LANSCE’s Lujan Center, and consists of two orthogonal planes of stationary sense wires for monitoring the beam distribution prior to its arrival at the target. A new data acquisition system has been developed for the 1L harp that features a National Instruments CompactRIO contained within a BiRIO chassis hosting electronic circuits for signal conditioning and a new feature for sense wire integrity monitoring. Hardware design, software architecture, and preliminary data acquisition results will be described.
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TUPD12	Development of Non-Invasive Electron Beam Position Monitor Based on Coherent Diffraction Radiation from a Slit	radiation, target, detector, linac	442
	Y. Taira, R. Kuroda, M. Tanaka, H. Toyokawa AIST, Tsukuba, Ibaraki, Japan K. Sakaue Waseda University, Tokyo, Japan H. Tomizawa RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	Funding: This work was supported by Grants-in-Aid for Scientific Research (26246046). Diffraction radiation (DR), which is closely related to transition radiation, is emitted when an electron passes near an edge or interface between two media with different dielectric constants. Theoretical and experimental investigation of DR is widely performing for a non-intercepting electron beam diagnostic. We have developed an electron bunch length and a beam position monitor using a coherent diffraction radiation (CDR), which is in the range of sub-millimeter wavelength. The frequency spectrum of CDR depends on a form factor expressed as the Fourier transform of the longitudinal particle distribution. We have measured the spatial intensity distribution of CDR emitted from the metallic edge with a terahertz camera. Total intensity passing through band pass filters (BPFs) was decreased as the transmission frequency of BPFs is increased up to 6 THz. The result indicates that the bunch length is few hundreds of femtosecond. A detailed data analysis is now performing. On the other hand, we have measured the intensity distribution of CDR emitted from the metallic rectangular slit. Bow-tie intensity distribution, aligned along the perpendicular direction to the slit edge, was measured with the terahertz camera. Moreover, when the electron beam did not pass through the center of the slit, an asymmetrical intensity distribution appeared. This asymmetry is due to the pre-wave zone effect. In short, we can found the beam position to the slit by measuring the asymmetry. In this conference, we will present the experimental results.
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TUPD16	Development of the Transverse Beam Profile Monitors for the PAL-XFEL	diagnostics, radiation, vacuum, target	452
	I.Y. Kim, J.Y. Choi, H. Heo, H.-S. Kang, C. Kim, G. Mun, B.G. Oh, S.J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	The PAL-XFEL is an X-ray free electron laser under construnction at the Pohang Accelerator Laboratory (PAL), Korea. In the PAL-XFEL, the electron beam can make coherent optical transition radiation (COTR) due to the microbunching instability in the compressed electron beam. In order to obtain transverse beam profiles without the COTR problem, we are developing scintillating screen monitors (with the geometric suppress method) and wire scanners. In this paper, we report test results at the test facility and progress in the development of the screen monitor and the wire scanner for the PAL-XFEL.
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TUPD24	Installation of a Beam Loss Monitoring System at the S-DALINAC*	controls, EPICS, radiation, monitoring	468
	L.E. Jürgensen, U. Bonnes, C. Burandt, M. Fischer, F. Hug, T. Kürzeder, N. Pietralla, R. Stegmann, M. Steinhorst TU Darmstadt, Darmstadt, Germany
	Funding: *Work supported by the BMBF through 05K13RDA The S-DALINAC is the superconducting linear accelerator of the Institut für Kernphysik at Technische Universität Darmstadt. It delivers an electron beam with energies up to 130 MeV. In order to get a short-time response about occurring beam losses and their locations a new system was tested and installed. The setup is based on beam loss monitors of Bergoz company using two pin-diodes to record primary electrons as well as secondary radiation in a coincidence set-up. The readout is done using a self-developed system of a supply unit including differential line-drivers and fast counting cards compatible to our EPICS-based control system. We will report on the installation of the whole system and its first commissioning as well as on the future use of the system for experiments on threshold currents for transverse beam break up.
	Poster TUPD24 [1.661 MB]
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WEIXB1	LCLS Beam Diagnostics	undulator, diagnostics, cavity, laser	475
	H. Loos SLAC, Menlo Park, California, USA
	Funding: Work supported by DOE contract DE-AC03-76SF00515 An extensive set of beam diagnostics has been one of the factors in the successful commissioning and operation of the Linac Coherent Light Source (LCLS) x-ray FEL over the last seven years. The originally developed and installed diagnostics were geared towards measuring the electron beam parameters of the LCLS design specifications. Since then, a number of improved and new diagnostics have been implemented to accommodate a much wider range of beam parameters and to overcome the challenges of diagnostics for a high brightness electron beam. Plans for the diagnostics of the LCLS-II project with its high repetition rate and high beam power and ongoing developments will also be discussed.
	Slides WEIXB1 [4.408 MB]
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WECZB3	Measurement of Beam Losses Using Optical Fibers at the Australian Synchrotron	detector, synchrotron, beam-losses, emittance	515
	E. Nebot Del Busto, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom M.J. Boland ASCo, Clayton, Victoria, Australia M.J. Boland, R.P. Rassool The University of Melbourne, Melbourne, Victoria, Australia E.B. Holzer, M. Kastriotou, E. Nebot Del Busto CERN, Geneva, Switzerland P.D. Jackson University of Adelaide, Adelaide, Australia J. Schmidt Albert-Ludwig Universität Freiburg, Freiburg, Germany C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The unprecedented requirements that new machines are setting on their diagnostic systems are leading to the development of a new generation of devices with large dynamic range, sensitivity and time resolution. Beam loss detection is particularly challenging due to the large extension of new facilities that need to be covered with localized detectors. Candidates to mitigate this problem consist of systems in which the sensitive part of the radiation detectors can be extended over the long distances of beam lines. In this document, we study the feasibility of a beam loss monitor (BLM) system based on optical fibers as an active detector for an electron storage ring. The Australian Synchrotron (AS) comprises a 216m ring that stores electrons up to 3GeV. The Accelerator has recently claimed the world record lowest transverse emittance (below 1 pm rad). Ultra low transverse sizes and large amounts of synchrotron radiation provide an environment very similar to that expected in the CLIC damping rings. A qualitative benchmark of beam losses under damping ring-like conditions is presented here. A wide range of beam loss rates can be achieved by modifying the bunch charge, horizontal/vertical coupling and dynamic aperture as well as via beam scrapers. The controlled beam losses are observed by means of the Cherenkov light produced in a 365 um core Silica fiber. The output light is coupled to different types of photo sensors namely: Multi Pixel Photon Counters (MPPCs), standard PhotoMulTiplier (PMT) tubes and Avalanche PhotoDiodes (APD). A detailed comparison of the sensitivities and time resolution obtained with the different read-outs are discussed in this contribution.
	Slides WECZB3 [2.755 MB]
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WEPF05	Simulation of the Beam Dump for a High Intensity Electron Gun	simulation, gun, scattering, collider	536
	A. Jeff, S. Döbert, T. Lefèvre CERN, Geneva, Switzerland A. Jeff The University of Liverpool, Liverpool, United Kingdom K. Pepitone CEA, LE BARP cedex, France
	The CLIC Drive Beam is a high-intensity pulsed electron beam. A test facility for the Drive Beam electron gun will soon be commissioned at CERN. In this contribution we outline the design of a beam dump / Faraday cup capable of resisting the beam’s thermal load. The test facility will operate initially up to 140 keV. At such low energies, the electrons are absorbed very close to the surface of the dump, leading to a large energy deposition density in this thin layer. In order not to damage the dump, the beam must be spread over a large surface. For this reason, a small-angled cone has been chosen. Simulations using geant4 have been performed to estimate the distribution of energy deposition in the dump. The heat transport both within the electron pulse and between pulses has been modelled using finite element methods to check the resistance of the dump at high repetition rates. In addition, the possibility of using a moveable dump to measure the beam profile and emittance is discussed.
	Poster WEPF05 [0.224 MB]
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WEPF07	Optimization of a Short Faraday Cup for Low-Energy Ions Using Numerical Simulations	ion, diagnostics, simulation, linac	544
	A.G. Sosa, E. Bravin, E.D. Cantero CERN, Geneva, Switzerland C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: CATHI is a Marie Curie Initial Training Network funded by the European Commission under Grant Agreement Number PITN-GA-2010-264330. ISOLDE, the heavy-ion facility at CERN is undergoing a major upgrade with the installation of a superconducting LINAC that will allow post-acceleration of ion beams up to 10 MeV/u. In this framework, customized beam diagnostics are being developed in order to fulfill the design requirements as well as to fit in the compact diagnostic boxes foreseen. The main detector of this system is a compact Faraday cup that will measure beam intensities in the range of 1 pA to 1 nA. In this contribution, simulation results of electrostatic fields and particle tracking are detailed for different Faraday cup prototypes taking into account the energy spectrum and angle of emission of the ion-induced secondary electrons.
	Poster WEPF07 [1.282 MB]
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WEPF08	Dosimetry of Pulsed Beams in Proton Therapy	proton, experiment, ion, high-voltage	548
	J. van de Walle, Y. Claereboudt, G. Krier, D. Prieels IBA, Louvain-la-Neuve, Belgium G. Boissonnat, J. Colin, J.-M. Fontbonne LPC, Caen, France
	Ion Beam Applications (IBA) has developed in recent years the ProteusONE proton therapy system, which aims at reducing the cost and footprint of proton therapy systems, making them affordable and accessible to more patients worldwide. The heart of the ProteusONE system is a super conducting synchro-cyclotron (S2C2), which provides short (10 μs) proton bunches at 1 kHz. This is in contrast to the proton therapy systems including the IBA Cyclone230, which delivers a continuous beam. Nevertheless, the same average dose rates are provided by both systems. As a consequence, the instantaneous dose rates with the S2C2 are much higher and recombination losses in the large area beam diagnostics and dosimetry devices become non negligible. Since the proton charge which is send to a patient should be measured with high precision, these recombination losses have to be addressed carefully. In this work, a large area (30x30 cm²) and large gap (>3 mm) ionization chamber (IC) is presented which allows to quantify recombination losses in each beam pulse on-line. The principle is based on the introduction of two ionization volumes in series with slightly different gap sizes. The ratio of detected charges in both IC's is the basic observable which is used to recalculate the efficiency of each IC. The principle of this so-called "asymmetric ionization chamber" (AIC) was tested with beam from the S2C2 prototype. The results show that the efficiency can be re-calculated to 0.5% precision for voltages higher than 1000 V. Together with the experimental results, the theoretical background of the recombination losses will be discussed and it will be shown how this theory is applied in a robust and simple way to correct for these losses in the proton therapy system.
	Poster WEPF08 [0.999 MB]
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WEPF09	Introduction to the Test Result of Turbo-ICT in PAL-ITF	monitoring, laser, diagnostics, pick-up	553
	H. J. Choi, M.S. Chae, H.-S. Kang, S.J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) built a PAL-ITF (Injector Test Facility) at the end of 2012 to successfully complete PAL-XFEL (X-ray Free Electron Laser) in 2015. The PAL-ITF is equipped with various kinds of diagnostic equipment to produce high-quality electron bunches. The three main parameters that an injection testing facility should measure are charge, energy and emittance. Although ICT and Faraday Cup were installed to measure beam charge, the noise generated in a klystron modulator not only interrupted accurate measurement but prevented low charges under tens of pC from being measured. Due to the changes in the overall voltage level of ITF, integration of ICT measured value failed to maintain perfect accuracy in terms of methodology (measured value continuously changed by ± 5pC). Accordingly, to solve the noise problems and accurately measure the quantity of electron beam charge, Turbo-ICT was installed. This paper focuses on the processes and test result of electric bunch charge quantity measurements using Turbo-ICT.
	Poster WEPF09 [2.807 MB]
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WEPF19	Fast Transverse Phase Space Measurement System for GunLab - A Compact Test Beamline for SRF Photoinjectors	emittance, quadrupole, SRF, gun	588
	J. Völker, T. Kamps HZB, Berlin, Germany
	Superconducting radiofrequency photo electron injectors (SRF guns) are promising electron sources for the next generation of electron linear accelerators. The energy recovery linac (ERL) BERLinPro will employ a 1.5 cell 1.3 GHz SRF gun cavity with normal conducting high quantum efficiency photocathode to produce a 100mA CW electron beam with high brightness. We are currently working on a compact test beamline (GunLab) to investigate the properties of the electron beam and to optimize the drive laser as well RF parameters. The motivation for GunLab is to decouple the SRF gun development from the ERL development. The goal is to measure not only the complete 6 dimensional phase space of the extracted and accelerated bunches but also to investigate dark current and beam halo. In this paper we will discuss unique features of GunLab for the phase space measurements.
	Poster WEPF19 [2.025 MB]
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WEPF21	Electron Cloud Density Measurements Using Resonant Microwaves at CesrTA	resonance, positron, storage-ring, photon	592
	J.P. Sikora Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA S. De Santis LBNL, Berkeley, California, USA
	Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505. Hardware has recently been installed in the Cornell Electron Storage Ring (CESR) to extend the capability of resonant microwave measurement of electron cloud density. Two new detector locations include aluminum beam-pipe in a dipole magnet and copper beam-pipe in a field free region. Measurements with both positron and electron beams are presented with both beams showing saturation of the electron cloud density in the aluminum chamber. These measurements were made at CESR which has been reconfigured as a test accelerator (CesrTA) with positron or electron beam energies ranging from 2 GeV to 5 GeV.
	Poster WEPF21 [1.988 MB]
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WEPD04	High Position Resolution and High Dynamic Range Stripline Beam Position Monitor (BPM) Readout System for the KEKB Injector Linac Towards the SuperKEKB	linac, positron, alignment, rf-amplifier	637
	R. Ichimiya, K. Furukawa, F. Miyahara, M. Satoh, T. Suwada KEK, Ibaraki, Japan
	The SuperKEKB accelerator is now being upgraded to bring the world highest luminosity (L=8x10³⁵/cm²/s). Hence, the KEKB injector linac has to produce low emittance and high charge electron (20 mm mrad, 7 GeV/c², 5 nC) and positron (20 mm mrad, 4 GeV/c², 4 nC) beam, respectively. In order to achieve these criteria, the accelerator structure has to be aligned within 0.1 mm position error. Since BPMs are essential instruments for beam based alignment (BBA), it is required to have one magnitude better position resolution to get enough alignment results. We have begun to develop high position resolution BPM readout system with narrow bandpass filters (fc = 180 MHz) and 250 MSa/s 16-bit ADCs. It handles two bunches with 96 ns interval separately and has a dynamic range from 0.1 nC to 10 nC. To compensate circuit drift, two calibration (x-direction and y-direction) pulses are output to the BPM electrodes between beam cycles (20 ms). Since it needs to achieve not only high position resolution but also good position accuracy, overall non-linearity within ±0.02 dB is required and the system has to have more than ±5 mm accurate position range. We confirmed the system performance with a 3-BPM resolution tests at KEK Injector Linac and it turned out that the system has 3 μm position resolution. We plan to install this system during 2015 summer shutdown.
	Poster WEPD04 [0.828 MB]
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WEPD08	Beam Jitter Spectra Measurements of the APEX Photoinjector	laser, gun, feedback, timing	652
	H.J. Qian, J.M. Byrd, L.R. Doolittle, Q. Du, D. Filippetto, G. Huang, F. Sannibale, R.P. Wells LBNL, Berkeley, California, USA J. Yang TUB, Beijing, People's Republic of China
	High repetition rate photoinjectors such as the APEX at LBNL are one of the enabling technologies for next generation MHz XFELs. Due to the higher repetition rate, a wider bandwidth is available for feedback systems to achieve ultra-stable beam performance. In a first step to improve APEX beam stability, the noise power spectra of the APEX laser beam and electron beam are characterized in terms of intensity and timing. Possible feedback systems are also discussed.
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THIXB1	Commissioning of the FLASH2 Electron Beam Diagnostics in Respect to its use at the European XFEL	diagnostics, electronics, undulator, vacuum	712
	N. Baboi, D. Nölle DESY, Hamburg, Germany
	This report presents the first operation experience of the electron beam diagnostics at FLASH2. FLASH2 is a new undulator line at the FLASH linac at DESY. Most electron beam diagnostics installed, like the beam loss monitors, cavity beam position monitors, toroids, beam halo monitors, have been designed for the European XFEL, and will provide operational experience beforehand. A few systems, as for example the button beam position monitors and the ionization chambers, have been developed for FLASH. The controls use the new MTCA.4 standard. Both linacs, FLASH and the European XFEL, require similar performance of the diagnostics systems. Many beam parameters are similar: bunch charge of 0.1 to 1 nC, pulse repetition frequency of 10 Hz, while others will be more critical at the XFEL than the ones currently used at FLASH, like the bunch frequency of up to 4.5 MHz. versus 1 MHz. The commissioning of FLASH2 and its diagnostics is ongoing. The beam monitors have accompanied the first beam through the linac, fine tuning for some systems is still to be done. The achieved performance will be presented in view of their use at the European XFEL.
	Slides THIXB1 [3.875 MB]
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THCXB1	Cross-Calibration of Three Electron Cloud Density Detectors at CesrTA	simulation, detector, photon, resonance	722
	J.P. Sikora, J.R. Calvey, J.A. Crittenden Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505. Measurements of electron cloud density using three detector types are compared under the same beam conditions at the same location in the Cornell Electron Storage Ring (CESR). Two of the detectors sample the flux of cloud electrons incident on the beam-pipe wall. The Retarding Field Analyzer (RFA) records the time-averaged charge flux and has a retarding grid that can be biased to select high energy electrons. The Shielded Button Electrode (SBE) samples the electron flux without a retarding grid, acquiring signals with sub-nanosecond resolution. The third detector uses resonant microwaves and measures the electron cloud density within the beam-pipe through the cloud-induced shift in resonant frequency. The analysis will include comparison of the output from POSINST and ECLOUD simulations of electron cloud buildup. These time-sliced particle-in-cell 2D modeling codes – simulating photoelectron production, secondary emission and cloud dynamics – have been expanded to include the electron acceptance of the RFA and SBE detectors in order to model the measured signals. The measurements were made at the CESR storage ring, which has been reconfigured as a test accelerator (CesrTA) providing electron or positron beams ranging in energy from 2 GeV to 5 GeV.
	Slides THCXB1 [3.240 MB]
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Paper

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Other Keywords

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MOCYB1

Non-Destructive Vertical Halo Monitor on the ESRF’s 6GeV Electron Beam

scattering, dipole, emittance, detector

2

K.B. Scheidt
ESRF, Grenoble, France

The population density along the electron’s beam vertical profile at far distance from the central core (i.e. the far-away tails or “halo”) is now quantitatively measurable by the use of bending magnet X-rays. An available beamport is equipped with two specifically adapted absorbers, an Aluminium UHV window, an X-ray light blocker, an X-ray imager, and a few motorizations. The simple and inexpensive set-up (much resembling that of an X-ray pinhole camera system for emittance measurements in Light Sources, but much shorter in length) allows the recording of images of the electron density profile over the 0.5 to 6mm distance range from the core. Results, obtained under various manipulations on the electron beam to vary either Touchek or residual Gas scattering and thereby the Halo levels, will be presented, to fully demonstrate that this Halo monitor is exploring those realms of the beam where other diagnostics can not reach .

Slides MOCYB1 [2.830 MB]

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MOCYB2

Design and Initial Commissioning of Beam Diagnostics for the KEK Compact ERL

linac, radiation, optics, emittance

7

R. Takai, T. Honda, T. Nogami, T. Obina, H. Sagehashi, Y. Tanimoto, M. Tobiyama
KEK, Ibaraki, Japan

A compact energy-recovery linac (cERL) was constructed at KEK as a test accelerator for the ERL-based light source. Standard beam monitors such as beam position monitors (BPMs), screen monitors (SCMs), and beam loss monitors (BLMs) have been developed for the cERL and used in its commissioning. For the main BPMs, we adopted the stripline type, the time response of which is improved by using a glass-sealed feedthrough. The SCMs are equipped with two types of screens and an RF shield for wake-field suppression. Optical fibers with photomultiplier tubes (PMTs), covering the entire cERL circumference, are used as the BLM. CsI scintillators with large-cathode PMTs are also prepared for detecting local beam loss. The design and some initial commissioning results of these standard monitors are described in this paper.

Slides MOCYB2 [4.987 MB]

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MOCYB3

Longitudinal Laser Wire at SNS

laser, ion, background, controls

12

A.P. Zhukov, A.V. Aleksandrov, Y. Liu
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
This paper describes a longitudinal H⁻ beam profile scanner that utilizes laser light to detach convoy electrons and an MCP to collect and measure these electrons. The scanner is located in MEBT with H⁻ energy of 2.5MeV and an RF frequency 402.5MHz. The picosecond pulsed laser runs at 80.5MHz in sync with the accelerator RF. The laser beam is delivered to the beam line through a 30m optical fiber. The pulse width after the fiber transmission measures about 10ps. Scanning the laser phase effectively allows measurements to move along ion bunch longitudinal position. We are able to reliably measure production beam bunch length with this method. The biggest problem we have encountered is background signal from electrons being stripped by vacuum. Several techniques of signal detection are discussed.

Slides MOCYB3 [4.519 MB]

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MOCZB3

Comparison of Feedback Controller for Link Stabilizing Units of the Laser Based Synchronisation System used at the European XFEL

controls, laser, feedback, timing

34

M. Heuer, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
G. Lichtenberg
HAW, Hamburg, Germany

The European X-ray Free Electron Laser will allow scientists to perform experiments with an atomic scale resolution. To perform time resolved experiments at the end of the facility it is essential to provide a highly stable clock signal to all subsystems. The accuracy of this signal is extremely important since it defines limitations of precise measurement devices. A laser based synchronization system is used for the synchronization with an error in sub-femtosecond range. These light pulses are carried by an optical fiber and exposed to external disturbances which changes the optical length of the fiber. For that reason the up to 4 kilometer long fibers are actively stabilized using a controller implemented on the new MicroTCA Platform. Due to the high computation resources of this platform it is possible to attack the time delay of the link system with well known model based feedback control strategies. This contribution shows the design of a model based controller for such a system and compares the control performance of the previously used PID controller with advanced control algorithms at the currently installed laboratory setup.

Slides MOCZB3 [4.973 MB]

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MOPF02

RHIC-Style IPMs in the Brookhaven AGS

detector, dipole, injection, acceleration

39

R. Connolly, W.C. Dawson, J.M. Fite, H. Huang, S.E. Jao, W. Meng, R.J. Michnoff, S. Tepikian
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. Department of Energy.
Beam profiles in the two storage rings of the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Lab (BNL) are measured with ionization profile monitors (IPMs). An IPM measures the distribution of electrons produced by beam ionization of background gas. These detectors have been developed at BNL in a program that began in 1996. The current detectors are a design from 2009. During the 2012 shutdown we refurbished the 2009 prototype detector and installed it in the Alternating-Gradient Synchrotron (AGS) for horizontal profiles. The commissioning tests were successful and in 2013 we built a new IPM for vertical profiles. In addition we placed coils on the backlegs of the permanent-magnet dipoles for beta-function measurements. This paper describes the AGS IPMs and shows data from the detector commissioning.

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MOPF05

Instrumentation for the Proposed Low Energy RHIC Electron Cooling Project with Energy Recovery

ion, emittance, gun, linac

49

D.M. Gassner, A.V. Fedotov, R.L. Hulsart, D. Kayran, V. Litvinenko, R.J. Michnoff, T.A. Miller, M.G. Minty, I. Pinayev, M. Wilinski
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
There is a strong interest in running RHIC at low ion beam energies of 7.7-20 GeV/nucleon [1]; this is much lower than the typical operations with 100 GeV/nucleon. The primary motivation for this effort is to explore the existence and location of the critical point on the QCD phase diagram. Electron cooling can increase the average integrated luminosity and increase the length of the stored lifetime. A cooling system is being designed that will provide a 30 – 50 mA electron beam with adequate quality and an energy range of 1.6 – 5 MeV. The cooling facility is planned to be inside the RHIC tunnel. The injector will include a 704 MHz SRF gun, a 704 MHz 5-cell SRF cavity followed by a normal conducting 2.1 GHz cavity. Electrons from the injector will be transported to the Yellow RHIC ring to allow electron-ion co-propagation for ~20 m, then a 180 degree U-turn electron transport so the same electron beam can similarly cool the Blue ion beam. After the cooling process with electron beam energies of 1.6 to 2 MeV, the electrons will be transported directly to a dump. When cooling with higher energy electrons between 2 and 5 MeV, after the cooling process, they will be routed through the acceleration cavity again to allow energy recovery and less power deposited in the dump. Special consideration is given to ensure overlap of electron and ion beams in the cooling section and achieving the requirements needed for cooling. The instrumentation systems described will include current transformers, beam position monitors, profile monitors, an emittance slit station, recombination and beam loss monitors.

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MOPF08

Beam Profile Measurements in the RHIC Electron Lens using a Pinhole Detector and YAG Screen

controls, software, detector, timing

59

T.A. Miller, M.R. Costanzo, W. Fischer, B. Frak, D.M. Gassner, X. Gu, A.I. Pikin
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
The electron lenses installed in RHIC are equipped with two independent transverse beam profiling systems, namely the Pinhole Detector and YAG screen. A small Faraday cup, with a 0.2mm pinhole mask, intercepts the electron beam while a pre-programmed routine automatically raster scans the beam across the detector face. The collected charge is integrated, digitized and stored in an image type data file that represents the electron beam density. This plungeable detector shares space in the vacuum chamber with a plunging YAG:Ce crystal coated with aluminum. A view port at the downstream extremity of the Collector allows a GigE camera, fitted with a zoom lens, to image the crystal and digitize the profile of a beam pulse. Custom beam profiling software has been written to import both beam image files (pinhole and YAG) and fully characterize the transverse beam profile. The results of these profile measurements are presented here along with a description of the system and operational features.
* W. Fischer, et al, "… head-on beam-beam compensation in RHIC", ICFA (BB3013), CERN (2013).
**T. Miller, et al, “… eLens pin-hole detector and YAG…“, BIW2012, Newport News, VA, TUPG039

Poster MOPF08 [6.731 MB]

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MOPF10

A Compact In-Air X-Ray Detector for Vertical Beam Size Measurement at ALBA

photon, dipole, detector, storage-ring

69

A.A. Nosych, U. Iriso
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

An in-air x-ray detector (IXD) was developed for ALBA to study the residual x-rays after traversing the 35mm copper crotch absorbers. The device prototype is placed in-air after such absorber, mounted flush with the vacuum pipe. The remaining x-rays (above 120 keV) generate a visible footprint if they impinge upon a sensitive enough scintillator. We are using a Cerium doped PreLude 420 (LuYSiO:Ce) screen, and the image is observed with a simple optics system mounted on a commercial CCD camera. This measurement allows evaluating the vertical electron beam size with exposure times in the order of seconds. Similar instruments are used at ESRF and ANKA storage rings. This paper presents the results of the first measurements with IXD and describes its potential to be used as a full diagnostics tool for the 3 GeV storage ring of ALBA.

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MOPF14

Vertical Beam Size Measurement at CesrTA Using Diffraction Radiation

target, radiation, background, polarization

77

L.M. Bobb, T. Aumeyr, P. Karataev
JAI, Egham, Surrey, United Kingdom
T. Aumeyr, P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
M.G. Billing, J.V. Conway
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
L.M. Bobb
DLS, Oxfordshire, United Kingdom
E. Bravin, T. Lefèvre, S. Mazzoni, H. Schmickler
CERN, Geneva, Switzerland

Over recent years the first Diffraction Radiation (DR) beam size monitor has been tested on a circular machine. At CesrTA, Cornell University, USA, the sensitivity and limitations of the DR monitor for vertical beam size measurement has been investigated. DR emitted from 1 and 0.5 mm target apertures was observed at 400 and 600 nm wavelengths. In addition, interference between the DR signals emitted by the target and mask has been observed. In this report, we present the recent observations and discuss areas for improvement.

Poster MOPF14 [3.379 MB]

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MOPF15

Status of and Future Plans for the CERN LINAC4 Emittance Meter based on Laser Electron-Detachment and a Diamond Strip-Detector

detector, laser, linac, emittance

83

T. Hofmann, E. Bravin, U. Raich, F. Roncarolo, F. Zocca
CERN, Geneva, Switzerland
G.E. Boorman, A. Bosco, S.M. Gibson, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria

Funding: LA3NET is funded by the European Commission under Grant Agreement Number GA-ITN-2011-289191
LINAC4 has started its staged commissioning at CERN. After completion it will accelerate high brightness H⁻ beams to 160 MeV. To measure the transverse profile and emittance of the beam, a non-destructive method based on electron photo-detachment is proposed, using a pulsed, fibre-coupled laser to strip electrons from the H⁻ ions. The laser can be focused and scanned through the H⁻ beam, acting like a conventional slit. A downstream dipole separates the neutral H⁰ beamlet, created by the laser interaction, from the main H⁻ beam, so that it can be measured by a diamond strip-detector. Combining the H⁰ beamlet profiles with the laser position allows the transverse emittance to be reconstructed. A prototype of this instrument was tested while commissioning the LINAC4 at 3 and 12 MeV. In this paper we shall describe the experimental setup, challenges and results of the measurements, and also address the characteristics and performance of the diamond strip-detector subsystem. In addition, the proposal for a permanent system at 160 MeV, including an electron detector for a direct profile measurement, will be presented.

Poster MOPF15 [0.994 MB]

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MOPF22

Simultaneous Operation of Two FEL Undulator Beamlines at FLASH

undulator, laser, FEL, operation

103

S. Ackermann, V. Ayvazyan, B. Faatz, E. Hass, K. Klose, S. Pfeiffer, M. Scholz, S. Schreiber
DESY, Hamburg, Germany

The FLASH FEL User Facility at DESY (Hamburg) is driven by a Photocathode RF gun and superconducting RF structures, producing up to 800 electron bunches per train with a repetition rate of 10 Hz. Because not all user experiments need the full pulse train (8000 FEL pulses per second), part of the electron bunches can be deflected into a second beamline, which can simultaneously deliver FEL pulses with different parameters to a second user experiment. To realize this possibility, the FLASH facility has been upgraded with a second undulator line and a second experimental Hall. In this contribution, we will present the new layout of the FLASH facility and the first results to operate it with different parameter sets. We will show present results achieved during the commissioning of the new beamline. Finally, we will give an outlook of further commissioning plans and user operation.
S. Ackermann for the FLASH II Team

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MOPF28

Beam Diagnostics and Timing Monitoring for SuperKEKB Injector Linac

linac, timing, positron, target

110

F. Miyahara, K. Furukawa, R. Ichimiya, N. Iida, M. Ikeno, H. Kaji, M. Satoh, M. Shoji, T. Suwada, M. Tanaka, Y. Yano
KEK, Ibaraki, Japan
T. Okazaki
EJIT, Hitachi, Ibaraki, Japan

The SuperKEKB injector linac has multiple operation modes for the electron beam injection into 3 separate rings, SuperKEKB HER, PF (Photon Factory) Ring and PF-AR, and the positron beam injection into the damping ring and the SuperKEKB LER. The operation modes can be switched every 20 milli-second with arbitrary order. The beam parameters such as charge, energy and emittance are different for each of the rings. Moreover, the bunch charge of the electron beam, 5nC, is 5 times higher and the emittance of ~10 mm•mrad is 30 times lower than those of the KEKB injector. Thus, development of BPM readout system with a wide dynamic range and installation of optical fiber detector with a good S/N ratio for the wire scanners and bunch-length monitor have been performed. For stable operation of the linac, many timing signals have to be monitored as well. To that end we have developed 32-bit multi-hit time-to-digital converters (TDCs) with 1-ns resolution. The first beam tests of those systems are reported in this paper.

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MOPF31

Overview of Beam Instrumentation Activities for SwissFEL

radiation, vacuum, undulator, pick-up

119

R. Ischebeck, R. Abela, F. Ardana-Lamas, V.R. Arsov, R. Baldinger, H.-H. Braun, M. Calvi, R. Ditter, C. Erny, F. Frei, R. Ganter, I. Gorgisyan, C.P. Hauri, S. Hunziker, P.N. Juranic, B. Keil, W. Koprek, R. Kramert, D. Llorente Sancho, F. Löhl, F. Marcellini, G. Marinkovic, B. Monoszlai, G.L. Orlandi, C. Ozkan, L. Patthey, M. Pedrozzi, P. Pollet, M. Radovic, L. Rivkin, M. Roggli, M. Rohrer, V. Schlott, A.G. Stepanov, J. Stettler
PSI, Villigen PSI, Switzerland
F. Ardana-Lamas, I. Gorgisyan, C.P. Hauri, L. Rivkin
EPFL, Lausanne, Switzerland
P. Peier
DESY, Hamburg, Germany

SwissFEL will provide users with brilliant X-ray pulses in 2017. A comprehensive suite of diagnostics is needed for the initial commissioning, for changes to the operating point, and for feedbacks. The development of instrumentation for SwissFEL is well underway, and solutions have been identified for most diagnostics systems. I will present here an overview of the instrumentation for SwissFEL, and give details on some recent developments.

Poster MOPF31 [4.418 MB]

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MOPD02

The Electron Backscattering Detector (eBSD), a New Tool for the Precise Mutual Alignment of the Electron and Ion Beams in Electron Lenses

ion, proton, detector, scattering

129

P. Thieberger, Z. Altinbas, C. Carlson, C. Chasman, M.R. Costanzo, C. Degen, K.A. Drees, W. Fischer, D.M. Gassner, X. Gu, K. Hamdi, J. Hock, Y. Luo, A. Marusic, T.A. Miller, M.G. Minty, C. Montag, A.I. Pikin, S.M. White
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
The Relativistic Heavy Ion Collider (RHIC) electron lenses, being commissioned to attain higher polarized proton-proton luminosities by partially compensating the beam-beam effect, require good alignment of the electron and proton beams. These beams propagating in opposite directions in a 5T solenoid have a typical rms width of 300 microns and need to overlap each other over an interaction length of about 2 m with deviations of less than ~50 microns. A new beam diagnostic tool to achieve and maintain this alignment is based on detecting electrons that are backscattered in close encounters with protons. Maximizing the intensity of these electrons ensures optimum beam overlap. The successful commissioning of these devices using 100 GeV/amu gold beams is described. Future developments are discussed that will further improve the sensitivity to small angular deviations.

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MOPD03

Performance and Upgrade of the Fast Beam Condition Monitor at CMS

luminosity, background, electronics, laser

134

M. Hempel, H.M. Henschel, O. Karacheban, W. Lange, J.L. Leonard, M. Penno
DESY Zeuthen, Zeuthen, Germany
K. Afanaciev
NC PHEP BSU, Minsk, Belarus
A.I. Bell
DLS, Oxfordshire, United Kingdom
P.R. Burtowy, A.E. Dabrowski, R. Loos, V. Ryjov, A.A. Zagozdzinska
CERN, Geneva, Switzerland
W. Lohmann
BTU, Cottbus, Germany
W. Lohmann, R. Walsh
DESY, Hamburg, Germany
B.L. Pollack
NU, Evanston, Illinois, USA
D. Przyborowski
AGH, Cracow, Poland
S. Schuwalow
Uni HH, Hamburg, Germany
D.P. Stickland
PU, Princeton, New Jersey, USA

The Fast Beam Condition Monitor BCM1F is a diamond based particle detector inside CMS. It is based on 8 single crystal CVD diamond sensors on both ends of the interaction point and is used for beam background and luminosity measurements. The system has been operated up to an integrated luminosity of 30fb-1, corresponding to a particle fluence of 8.78·10¹³ cm^-2 (24GeV proton equivalent). To maintain the performance at a bunch spacing of 25ns and at the enhanced luminosity after the LHC Long Shutdown LS1, an upgrade of BCM1F is necessary. The upgraded system features 24 single crystal diamond sensors with a two pad metallization, a very fast front-end ASIC built with 130nm CMOS technology and new back-end electronics. A prototype of the upgraded BCM1F components were studied in the 5GeV electron beam at DESY. Measurements were done on the signal shape as function of time, the collection efficiency as a function of voltage and position of the impact point on the sensor surface. The preliminary results of this testbeam will be presented. In addition, the status of the new upgraded BCM1F will be given.

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MOPD05

Dual Transverse and Longitudinal Streak Camera Imaging at ELSA

damping, cavity, diagnostics, synchrotron

144

M.T. Switka, F. Frommberger, P. Hänisch, W. Hillert, M. Schedler
ELSA, Bonn, Germany

Funding: Funded by the German Research Foundation (DFG) within Colaborative Research Center (SFB/TRR) 16
The electron pulse stretcher ring ELSA located at Bonn University provides 0.5 – 3.5 GeV polarized and non-polarized electron beams for external experimental stations. A streak camera system has been installed to capture time resolved images of beam dynamics ranging from nanoseconds to several milliseconds. Particular attention was drawn to the capability of simultaneous imaging of both transverse beam dimensions, hence providing information of all spatial dimensions in one synchroscan or slow sweep measurement. Incoherent and coherent beam instabilities, especially at high stored beam currents, are subject of analysis due to the planned intensity upgrade towards 200 mA for standard operation. The current resolution performance of the imaging system and machine relevant measurements are presented.

Poster MOPD05 [6.133 MB]

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MOPD06

Electron Beam Diagnostics for Short Pulse FEL Schemes at CLARA

laser, FEL, diagnostics, simulation

147

S. Spampinati, D. Newton
Cockcroft Institute, Warrington, Cheshire, United Kingdom
D. Newton
The University of Liverpool, Liverpool, United Kingdom

CLARA (Compact Linear Accelerator for Research and Applications) [1] is a proposed 250 MeV, 100-400 nm FEL test facility at Daresbury Laboratory. The purpose of CLARA is to test and validate new FEL schemes in areas such as ultra-short pulse generation, temporal coherence and pulse-tailoring. Some of the schemes that can be tested at CLARA depend on a manipulation of the electron beam properties with characteristic scales shorter than the electron beam and require a 30 - 50 μm modulation of the beam energy acquired via the interaction with an infrared laser beam in a short undulator. In this article we describe the electron beam diagnostics required to carry on these experiments.

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MOPD08

A Double-Prism Spectrometer for the Longitudinal Diagnosis of Femtosecond Electron Bunches with Mid-Infrared Transition Radiation

radiation, detector, diagnostics, FEL

157

S. Wunderlich, E. Hass, B. Schmidt, M. Yan
DESY, Hamburg, Germany

Funding: The project has been supported by the BMBF under contract 05K10GU2 & FS FLASH 301.
Electron bunch lengths in the sub-10 fs regime and charges of a few tens of picocoulombs are parameters required for free-electron lasers [*] and are also a consequence from the intrinsic process in laser-driven plasma wake field acceleration [**]. Since the coherent spectrum of transition radiation of these bunches carries the information on the longitudinal bunch profile in the form factor, the spectroscopy of transition radiation is an attractive method to determine the electron bunch length. A double-prism spectrometer has been developed and demonstrated for the single-stage measurement of mid-infrared transition radiation between 2 μm and 18 μm. The spectrometer facilitates single-shot spectral measurements with high signal-to-noise ratio utilising a line array of mercury cadmium telluride detectors. In this contribution, we present the spectrometer and measurements of electron bunches of the Free-Electron Laser in Hamburg (FLASH) at DESY. The results are compared to established bunch length monitors which are a multi-stage grating spectrometer for transition radiation and a transverse deflecting structure accessing the longitudinal phase space of the electron bunches directly.
*J. Rönsch-Schulenburg et al., Proceedings of FEL 2014, TUB04 (2014), to be published
**O. Lundh et al., Nature Physics 7, 219–222 (2011)

Poster MOPD08 [1.346 MB]

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MOPD09

Longitudinal Phase Space Tomography Using a Booster Cavity at the Photo Injector Test Facility at DESY, Zeuthen Site (PITZ)

laser, booster, acceleration, gun

161

D. Malyutin, M. Groß, I.I. Isaev, M. Khojoyan, G. Kourkafas, M. Krasilnikov, B. Marchetti, F. Stephan, G. Vashchenko
DESY Zeuthen, Zeuthen, Germany

One of the ways to measure the longitudinal phase space of the electron bunch in a linear accelerator is a tomographic technique based on measurements of the bunch momentum spectra while varying the bunch energy chirp. The energy chirp at PITZ can be controlled by varying the RF phase of the CDS booster – the accelerating structure installed downstream the electron source (RF gun). The resulting momentum distribution can be measured with a dipole spectrometer downstream. As a result, the longitudinal phase space at the entrance of the CDS booster can be reconstructed. In this paper the tomographic technique for longitudinal phase space measurements is described. Results of measurements at PITZ are presented and discussed.

Poster MOPD09 [0.925 MB]

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MOPD10

New Results Of FERMI FEL1 EOS Diagnostics With Full Optical Synchronization

laser, FEL, diagnostics, electronics

165

M. Veronese, E. Allaria, P. Cinquegrana, E. Ferrari, F. Rossi, P. Sigalotti, C. Spezzani
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
E. Ferrari
Università degli Studi di Trieste, Trieste, Italy

The Electro Optical Sampling diagnostics (EOS) of the FERMI FEL has been recently upgraded with a full optical synchronization of its dedicated femtosecond fiber laser to the ultra-stable optical pulsed timing system of FERMI. For this purpose a dual synchronization electronics has been developed and installed. It exploits a mixed error signal derived from both optical to electrical conversion and from a second harmonic generation based optical phase detection. For this second part a new optical setup including a cross correlator has been installed. The operation of the EOS has greatly benefited from the upgrade. The arrival time measurements have been compared with the ones from the bunch arrival monitor diagnostics (BAM) showing very good agreement. This new setup has also allowed to improve the bunch profile measurement. Some examples of measurement with ZnTe and GaP are presented. Finally, usability and operator friendliness of the new setup are also discussed.

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MOPD12

Novel Femtosecond Level Synchronization of Titanium Sapphire Laser and Relativistic Electron Beams

laser, polarization, plasma, timing

174

M. Titberidze, F.J. Grüner, A.R. Maier
Uni HH, Hamburg, Germany
M. Felber, K. Flöttmann, T. Lamb, H. Schlarb, C. Sydlo
DESY, Hamburg, Germany
F.J. Grüner, A.R. Maier, B. Zeitler
CFEL, Hamburg, Germany
E. Janas
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland

Laser driven plasma accelerators are offering high gradient (~ 10-100GV/m), high quality (low emittance, short bunch length) electron beams which can be suitable for future compact, bright and tunable light sources. In the framework of the Laboratory for Laser- and beam-driven plasma Acceleration (LAOLA) collaboration at Deutsches Elektronen-Synchrotron (DESY) the external injection experiment for injecting electron bunches from a conventional RF accelerator into the linear plasma wave is in progress. External injection experiments at REGAE (Relativistic Electron gun for Atomic Exploration) require sub-10 fs precision synchronization of laser and electron beams in order to perform a beam scan into the plasma wave by varying the delay between electron beam and laser pulses. In this paper we present a novel optical to microwave synchronization scheme, based on a balanced single output integrated Mach-Zehnder Modulator (MZM). The scheme offers a highly sensitive phase detector between a pulsed 800 nm Ti:Sa laser and a 3GHz microwave reference source. It is virtually independent of input laser power fluctuation and it offers femtosecond long-term precision. Together with the principal of operation of this setup, we will present promising preliminary experimental results of the detector stability.

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MOPD15

CW Beam Stability Analysis in Time and Frequency Domain

diagnostics, high-voltage, radiation, laser

179

M. Kuntzsch, M. Gensch, B.W. Green, S. Kovalev, U. Lehnert, P. Michel, R. Schurig, J. Teichert
HZDR, Dresden, Germany

The superconducting quasi CW Linac ELBE has been characterized in terms of energy and timing stability. The measurement results presented show a combination of a laser-based bunch arrival-time measurements (BAM), a fast beam position monitor (BPM) readout with single bunch resolution and a compression monitor (BCM) based on a fast pyro-electric detector. By changing the bunch compression factor a separation and identification of jitter sources has been achieved. The quasi CW mode of operation enables frequency domain data analysis with high dynamic range, which gives a better understanding of the main sources of jitter. Experimental results for both injectors (thermionic DC, superconducting RF) are presented.

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MOPD17

Single-Shot Electro-Optical Diagnostics at the ANKA Storage Ring

laser, storage-ring, wakefield, operation

182

N. Hiller, A. Borysenko, E. Hertle, V. Judin, B. Kehrer, A.-S. Müller, M.J. Nasse, M. Schuh, P. Schönfeldt, N.J. Smale, J.L. Steinmann
KIT, Karlsruhe, Germany
P. Peier, B. Steffen
DESY, Hamburg, Germany
V. Schlott
PSI, Villigen PSI, Switzerland

Funding: This work is funded by the BMBF contract numbers: 05K10VKC, 05K13VKA.
ANKA is the first storage ring in the world with a near-field single-shot electro-optical (EO) bunch profile monitor. The method of electro-optical spectral decoding (EOSD) uses the Pockels effect to modulate the longitudinal electron bunch profile onto a long, chirped laser pulse passing through an EO crystal. The laser pulse is then analyzed with a single-shot spectrometer and from the spectral modulation, the temporal distribution can be extracted. The setup is tuned to a sub-ps resolution (granularity) and can measure down to bunch lengths of 1.5 ps RMS for bunch charges as low as 30 pC. With this setup it is possible to study longitudinal beam dynamics (e. g. microbunching) occurring during ANKA's low-alpha-operation, an operation mode with longitudinally compressed bunches to generate coherent synchrotron radiation in the THz range. In addition to measuring the longitudinal bunch profile, long-ranging wake-fields trailing the electron bunch can also be studied, hinting bunch-bunch interactions.

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MOPD24

Diagnostics of and with Laser-Induced Energy Modulation at the DELTA Storage Ring

laser, radiation, undulator, storage-ring

202

S. Khan, S. Hilbrich, H. Huck, M. Huck, M. Höner, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, P. Ungelenk
DELTA, Dortmund, Germany

Funding: This work is supported by the BMBF (05K13PEC) and DFG (INST212/236-1) and by the Land NRW.
DELTA is a 1.5-GeV electron storage ring operated by the Center for Synchrotron Radiation at the TU Dortmund University. An interaction between electron bunches and femtosecond laser pulses is routinely used to generate ultrashort pulses of coherent synchrotron radiation at harmonics of the laser wavelength (coherent harmonic generation, CHG) as well as short and coherent pulses in the THz regime. The paper describes diagnostics methods to optimize the laser-electron overlap and to characterize the generated VUV and THz pulses. Furthermore, the laser-electron interaction can be employed as a beam diagnostics tool, e.g. to study the longitudinal steady-state bunch profile as well as dynamic properties during RF-phase modulation, which is applied to improve the beam lifetime.

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MOPD25

Time Domain Pickup Signal characterization for Low Charge Arrival-Time Measurements at FLASH

pick-up, simulation, laser, operation

209

A. Angelovski, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
M.K. Czwalinna, H. Schlarb, C. Sydlo
DESY, Hamburg, Germany
T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

For the low charge operation mode at the European XFEL, high bandwidth cone-shaped pickups were developed as a part of the Bunch Arrival-time Monitors (BAMs). The simulation showed that the signal parameters of interest, the signal slope and bandwidth are improved by more than a factor of six compared to the state of the art pickups. The pickups are installed at FLASH for verification. In this paper, time-domain measurements of the cone-shaped pickups at FLASH are presented. The pickup signal is recorded with a high bandwidth sampling oscilloscope. Two channel measurements are conducted with a single and a combined pickup signal in order to analyze the orbit and charge dependence of the pickup signal parameters. The measured time domain pickup signal wave form is compared to the CST PARTICLE STUDIO simulation.

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TUIXB1

The Beam Instrumentation and Diagnostic Challenges for LHC Operation at High Energy

detector, synchrotron, emittance, quadrupole

216

O.R. Jones
CERN, Geneva, Switzerland

This contribution will present the role of beam instrumentation and diagnostics in facing the challenges posed by running the LHC close to its design energy of 7TeV. Machine protection will be ever more critical, with the quench level of the magnets significantly reduced, so relying heavily on the beam loss system and abort gap monitor interlocks on the beam position and fast beam current change system. Non-invasive profile monitoring also becomes more of a challenge, with standard synchrotron light imaging limited by diffraction and rest gas ionisation monitoring dominated by space charge effects. There is also a requirement to better understand beam instabilities, of which several were observed during Run I, leading to the need for synchronised bunch-by-bunch, turn-by-turn information from many distributed instrumentation systems. All of these challenges will be discussed along with the strategies adopted to overcome them.

Slides TUIXB1 [7.329 MB]

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TUCYB2

Pulsed Green Laser Wire System for Effective Inverse Compton Scattering

laser, cavity, emittance, experiment

254

A.A. Rawankar, N. Terunuma, J. Urakawa
Sokendai, Ibaraki, Japan
T. Akagi, A.S. Aryshev, Y. Honda, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
D. Jehanno
LAL, Orsay, France
K. Sakaue
Waseda University, Tokyo, Japan

Funding: This work has been supported by the Quantum Beam Technology Program of the Japanese Ministry of Education, Culture, Sports, Science,and Technology(MEXT).
Laser-Compton scattering has become an important technique for beam diagnostics of the latest accelerators. In order to develop technologies for low emittance beams, an Accelerator Test facility (ATF) was built at KEK. It consists of an electron linac, a damping ring in which beam emittance is reduced, and an extraction line. For emittance measurement we are developing a new type of beam profile monitor which works on the principle of inverse Compton scattering between electron and laser light. In order to achieve effective collision of photon and electron, a pulsed and very thin size laser is required. Laser wire is one technique of measuring a small beam size. With green lasers, which are converted to second harmonics from IR pulsed laser, minimum beam waist is half of the beam waist obtained using infrared (IR) laser oscillator. Therefore, it is possible to obtain beam waist less than 5 μm using green laser pulse, which is required for effective photon-electron collision. First, pulsed IR seed laser is amplified with 1.5 meter long PCF based amplifier system. This pulsed IR laser is converted to second harmonics with a non-linear crystal. Pulsed green laser is injected inside four mirror optical cavity to obtain very small beam waist at interaction point (IP). Using a pulsed compact laser wire, we can measure 10 um electron beams in vertical directions. We report the development of the pulsed green laser and parameters of compact four mirror optical cavity for effective inverse Compton scattering.

Slides TUCYB2 [2.632 MB]

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TUCYB3

SwissFEL Beam Profile Monitor

radiation, vacuum, laser, detector

259

R. Ischebeck, E. Prat, V. Schlott, V.G. Thominet
PSI, Villigen PSI, Switzerland
P. Krejcik, H. Loos
SLAC, Menlo Park, California, USA
M. Yan
DESY, Hamburg, Germany

We have developed a beam profile monitor that allows us to measure two-dimensional electron beam profiles for highly compressed electron bunches. Such bunches have plagued profile measurements in optical transition radiation monitors in the past, because coherent radiation entering the optical system has invalidated the images and even destroyed cameras. The present design makes use of a scintillating crystal, and directs coherent transition radiation away from the optical axis by careful choice of the angle. When observing Snell's law of refraction as well as the Scheimpflug imaging condition, a resolution better than the thickness of the scintillator can be achieved. We will present measurements performed at the SwissFEL Injector Test Facility and at the Linac Coherent Light Source. The high resolution and excellent sensitivity of this monitor make it ideal for installation in SwissFEL.

Slides TUCYB3 [42.624 MB]

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TUIZB1

Radiation Sources and Their Application for Beam Profile Diagnostics

radiation, photon, diagnostics, optics

263

G. Kube
DESY, Hamburg, Germany

Radiation generated by high-energy particle beams is widely used for beam diagnostic purposes. Depending on the mechanism of radiation generation, the emitted wavelength range extends from the THz up to the X-ray region, thus allowing the measurement of beam profiles in the longitudinal and the transverse plane over a wide range. In this talk, basic considerations for radiation based profile measurements will be discussed with special emphasis on the mechanism of radiation generation and the impact on beam diagnostic measurements.

Slides TUIZB1 [4.803 MB]

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TUCZB1

Novel Emittance Diagnostics for Diffraction Limited Light Sources Based on X-ray Fresnel Diffractometry

emittance, radiation, diagnostics, betatron

274

M. Masaki, Y. Shimosaki, S. Takano, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan

A novel emittance diagnostics technique with high sensitivity using X-ray Fresnel diffraction by a single slit has been developed to measure micron-order electron beam sizes at insertion devices (IDs) of photon beamlines. The X-ray Fresnel diffractometry (XFD)* is promising for diagnostics especially of a so-called diffraction limited storage ring (DLSR) with ultra-low emittance. In the DLSR, due to inevitable field errors of strong quadrupole and sextupole magnets, unwanted distortion of lattice functions and local betatron coupling will result in a different light source size at each beamline. Therefore, measurements of electron beam sizes at the ID source points will be essential to ensure the absence of degradation of brilliance and transverse coherence of radiation at the beamlines. The XFD observes a double-lobed diffraction pattern that emerges by optimizing the single slit width. The principle is based on a correlation between the depth of a median dip in the double-lobed pattern and the light source size at the ID. The validity of the new technique was theoretically and experimentally studied. The achievable resolution of the XFD will be also discussed.
* M. Masaki, et al.,"X-ray Fresnel Diffractometry for Ultra-Low Emittance Diagnostics of Next Generation Synchrotron Light Sources", submitted to Phys. Rev.ST-AB.

Slides TUCZB1 [5.456 MB]

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TUCZB2

Measurements of Small Vertical Beamsize using a Coded Aperture at Diamond Light Source

radiation, detector, synchrotron, synchrotron-radiation

279

C. Bloomer, G. Rehm
DLS, Oxfordshire, United Kingdom
J.W. Flanagan
KEK, Ibaraki, Japan

Diamond Light Source produces a low emittance 3GeV electron beam which is now regularly operated at 8pm.rad vertical emittance. This corresponds to a vertical beamsize of just 13um in the dipole, which is at a high vertical beta location and routinely used for observing the synchrotron radiation using a pinhole camera. Deconvolution of the images from the pinhole camera to maximise resolution is limited by uncertainly regarding the precise shape of the pinhole, resulting in uncertainty on its computed point spread function. Recently a coded aperture has been installed which offers the potential to improve upon the traditional pinhole measurement by offering both higher resolution and increased flux seen through a larger total aperture, however, at the cost of significantly more complex analysis of the recorded images. A comparison of results obtained using the coded aperture and those achieved using the conventional pinhole is presented.

Slides TUCZB2 [4.199 MB]

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TUCZB3

A Quantum Gas Jet for Non-Invasive Beam Profile Measurement

ion, focusing, photon, vacuum

284

A. Jeff, E.B. Holzer, T. Lefèvre
CERN, Geneva, Switzerland
A. Jeff, V. Tzoganis, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
V. Tzoganis, C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom

A novel instrument for accelerator beam diagnostics is being developed by using De Broglie-wave focusing to create an ultra-thin neutral gas jet. Scanning the gas jet across a particle beam while measuring the interaction products, the beam profile can be measured. Such a jet scanner will provide an invaluable diagnostic tool in beams which are too intense for the use of wire scanners, such as the proposed CLIC Drive Beam. In order to create a sufficiently thin jet, a focusing element working on the DeBroglie wavelength of the Helium atom has been designed. Following the principles of the Photon Sieve, we have constructed an Atomic Sieve consisting of 5230 nano-holes etched into a thin film of silicon nitride. When a quasi-monochromatic Helium jet is incident on the sieve, an interference pattern with a single central maximum is created. The stream of Helium atoms passing through this central maximum is much narrower than a conventional gas jet. The first experiences with this device are presented here, along with plans for further tests.

Slides TUCZB3 [13.880 MB]

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TUPF02

Proposed Pulse Stretching of BPM Signals for the Position Determination of Very Short and Closely Spaced Bunches

simulation, synchrotron-radiation, collider, synchrotron

294

P. Thieberger, S.J. Brooks, K. Hamdi, R.L. Hulsart, G.J. Mahler, R.J. Michnoff, M.G. Minty, D. Trbojevic
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
A proposal for a future ultra relativistic polarized electron-proton collider (eRHIC) is based in part on the transport of multiple electron beams of different energies through two FFAG beam transports around the 3834 m long RHIC tunnel circumference in order to recirculate them through an Energy Recovery Linac for their stepwise acceleration and deceleration. For each of these transports, the beams will travel in a common vacuum chamber, horizontally separated from each other by a few mm. Determining the position of the individual bunches is challenging due to their very short length (~12 ps rms) and their temporal proximity (less than 4 ns in some cases). Providing pulses adequate for accurate sampling is further complicated by the less-than-ideal response of long coaxial cables. Here we propose two approaches to produce enhanced, i.e. stretched pulse shapes of limited duration; one based on specially shaped BPM electrodes and the other one on analog integration of more conventional stripline BPM signals. In both cases, signals can be generated which contain relatively flat portions which should be easier to sample with good precision without requiring picoseconds timing accuracy.

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TUPF08

Design, Development and Commissioning of a MTCA-Based Button and Strip-Line BPM System for FLASH2

electronics, timing, operation, undulator

320

B. Lorbeer, N. Baboi, L.P. Petrosyan, F. Schmidt-Föhre
DESY, Hamburg, Germany

The FLASH (Free Electron Laser in Hamburg) facility at DESY (Deutsches Elektronen-Synchrotron) in Germany has been extended by a new undulator line called FLASH2 to provide twice as many experimental stations for users in the future*. After the acceleration of the electron bunch train up to 1.2GeV, a part can be kicked into FLASH2, while the other is going to the old undulator line. In order to tune the wavelength of the SASE (Self Amplified Spontaneous Emission), the new line is equipped with variable gap undulators. The commissioning phase of FLASH2 started in early 2014 and is planned to be continued parasitically during user operation in FLASH1. One key point during first beam commissioning is the availability of standard diagnostic devices such as BPM (Beam Position Monitor). In this paper we present the design and first operational experience of a new BPM system for button and strip-line monitors based on MTCA.4***. This is referred to as LCBPM (low charge BPM) in contrast to the old systems at FLASH initially designed for bunch charges of 1nC and higher. We summarize the recent analog and digital hardware development progress[**,****] and first commissioning experience of this new BPM system at FLASH2 and present a first estimation of its resolution in a large charge range from 1nC down to 100pC and smaller.
* flash2.desy.de
** B. Lorbeer et.al.,TUPA19, IBIC2012
*** MTCA.4 (Micro Telecommunications Computing Architecture ) for physics
**** Frank Schmidt-Foehre et.al.,IPAC2014 Dresden

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TUPF09

Calibration of OLYMPUS/DORIS Beam Position Monitors

electronics, experiment, positron, target

324

U. Schneekloth, N. Görrissen, G. Kube, J. Neugebauer, Ru. Neumann, F. Schmidt-Föhre
DESY, Hamburg, Germany

The goal of the OLYMPUS experiment is a precise measurement of the ratio of the positron-proton and electron-proton elastic scattering cross sections in order to quantify the effect of two-photon exchange. The experiment was performed using intense beams of electrons and positrons stored in the DORIS ring at Deutsches Elektronen Synchrotron in Hamburg, impinging on an un-polarized, internal, hydrogen gas target. An essential ingredient of the experiment is a precise determination of the luminosity, which requires a precise knowledge of the beam position of both beam species. During DORIS operation cylindrical button beam position monitors, read out by two independent electronics systems, were mounted up- and downstream of the target chamber. After the end of operation, the readout systems were cross-calibrated. The BPMs were then calibrated using a test-stand, consisting of a wire scanner assembly. The beam was simulated by applying an RF signal to the wire. This paper describes the calibration principles and test setup, together with the results compared to the expected BPM response.

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TUPF13

Diamond-Based Photon BPMs for Fast Electron-Beam Diagnostics in Synchrotron Radiation Sources

photon, radiation, diagnostics, detector

342

M. Antonelli, G. Cautero, D. Giuressi, S. Lizzit, R.H. Menk
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
A. De Sio, E. Pace
Università degli Studi di Firenze, Firenze, Italy
M. Di Fraia
Università degli Studi di Trieste, Trieste, Italy

Electron-beam stability is amongst the primary concerns in current Synchrotron Radiation (SR) sources; in particular, in third-generation SR facilities high-brightness beamlines using undulator radiation are extremely sensitive to electron-beam oscillations. Orbit stabilization has been intensively addressed in the past years and many SR machines have been equipped with a Fast Orbit Feedback (FOFB) based on electron Beam-Position Monitors (eBPMs). On the other hand, photon Beam-Position Monitors (pBPMs), besides providing beamline users with crucial calibration data, are also a useful tool for keeping the electron beam under control, by monitoring position and intensity of the delivered radiation. The machine control system can take advantage of this information in order to improve the stability of the electron-beam. A diagnostic beamline, utilizing a couple of fast pBPMs based on single-crystal CVD diamond detectors, has been built and inserted into the central dead-end outlet of one of Elettra’s bending-magnets. Tests have been carried out both during normal machine operations and by deliberately moving the orbit during dedicated shifts. Owing to the outstanding properties of diamond in terms of speed and radiation hardness, the results show how the aforementioned system allows the beam position to be monitored with sub-micrometric precision at the demanding readout rates required by the FOFB. The radiation hardness of the sensors allows the operation over extended periods of time without special maintenance. Therefore, this system is particularly suited for storage-ring sections lacking in electron-beam monitoring and the tested diagnostic line represents a demonstrator for future implementation of pBPMs at several bending-magnet front ends of Elettra.

Poster TUPF13 [3.409 MB]

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TUPF18

Development of a Button BPM for the LCLS-II project

diagnostics, wakefield, feedback, HOM

361

A. Lunin, T.N. Khabiboulline, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

A high sensitivity button BPM is under development for a linac section of the LCLS-II project. Since the LCLS-II linac will operate with bunch charge as low as 10 pC, we analyse various options for pickup button and feedthrough in order to maximize the BPM output signal at low charge regime. As a result the conceptual BPM design is proposed including an analytical estimation of the BPM performance as well as numerical simulation with CST Particle Studio and ANSYS HFSS. Both numerical methods show a good agreement of BPM output signals for various design parameters. Finally we describe the signal processing scheme and the electronics we are going to use.

Poster TUPF18 [0.846 MB]

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TUPF25

Characterization of the Laser Beam for HHG Seeding

FEL, simulation, laser, undulator

380

S. Ackermann, B. Faatz
DESY, Hamburg, Germany
V. Miltchev
Uni HH, Hamburg, Germany

Recently free-electron laser (FEL) facilities around the world have shown that the direct seeding approach can enhance the spectral, temporal and coherence properties of the emitted radiation as well as reducing the fluctuations in arrival time and output energy. To achieve this, a photon pulse of the desired wavelength ("seed") is overlapped transversely and temporally with the electrons in the undulator to start up the FEL process from a defined radiation pulse rather than from noise. To benefit from the advantages of this technique, the energy of the seed has to exceed the energy of the spontaneous emission. The ratio between these two energies is strongly influenced by the seed beam properties. In this contribution, we will present simulations on the achieveable power contrast in dependence on the beam quality of the seed, and compare the results to the experimental data of the seeded FEL experiment ("sFLASH") at DESY, Hamburg. Additionally we show up a way of creating FEL seed pulses for simulation purposes from Hermite-Gaussian generating functions.

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TUPF26

Linear Focal Cherenkov-Ring Camera for Single Shot Observation of Longitudinal Phase Space Distribution for Non-Relativistic Electron Beam

vacuum, laser, gun, photon

385

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

A test accelerator for the coherent THz source (t-ACTS) has been constructed at Tohoku University, in which the generation of intense coherent THz radiation from sub-picosecond electron bunches will be demonstrated. The final electron bunch length of accelerated beam is mostly dictated by the longitudinal phase space distribution at the exit of electron-gun. Therefore, measurement of Initial electron distribution in the longitudinal phase space produced by an electron gun is crucial for stable production of very short electron bunches, However, measurement of the longitudinal phase space of a relatively lower energy electron beam is especially difficult because space charge effects in drift spaces for measurement system might be strong. A method for measurement of electron energy (or momentum) applying velocity dependence of the opening angle of Cherenkov radiation in the radiator has been proposed for relatively lower energy electrons. Combined use of a streak camera and the “turtle-back” mirror that confines the Cherenkov light onto a linear focal line may allow us to observe the longitudinal phase space distribution directly. Current status of the system development will be reported in this conference.

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TUPD02

Electron Beam Profiler for the Fermilab Main Injector

proton, gun, simulation, ion

398

R.M. Thurman-Keup, M.L. Alvarez, J. Fitzgerald, C.E. Lundberg, P.S. Prieto
Fermilab, Batavia, Illinois, USA
W. Blokland
ORNL, Oak Ridge, Tennessee, USA

The long range plan for Fermilab calls for large proton beam intensities in excess of 2 MW for use in the neutrino program. Measuring the transverse profiles of these high intensity beams is challenging and generally relies on non-invasive techniques. One such technique involves measuring the deflection of a beam of electrons with a trajectory perpendicular to the proton beam. A device such as this is already in use at the Spallation Neutron Source at ORNL and a similar device will be installed shortly in the Fermilab Main Injector. The Main Injector device is discussed in detail and some test results and simulations are shown.

Poster TUPD02 [2.115 MB]

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TUPD04

Third Generation Residual Gas Ionization Profile Monitors at Fermilab.

controls, detector, proton, ion

408

J.R. Zagel, M.L. Alvarez, B.J. Fellenz, C.C. Jensen, C.E. Lundberg, E.S.M. McCrory, D. Slimmer, R.M. Thurman-Keup, D.G. Tinsley
Fermilab, Batavia, Illinois, USA

Funding: DOE
The latest generation of IPM's installed in the Fermilab Main Injector and Recycler incorporate a 1 kG permanent magnet, a newly designed high-gain, rad-tolerant preamp, and a control grid to moderate the charge that is allowed to arrive on the anode pick-up strips. The control grid is intended to select a single Booster batch measurement per turn. Initially it is being used to allow for a faster turn-on of a single, high-intensity cycle in either machine. The expectation is that this will extend the Micro Channel Plate lifetime, which is the high-cost consumable in the measurement system. We discuss the new design and data acquired with this system.

Poster TUPD04 [11.950 MB]

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TUPD07

Performance Demonstration of the Non-Invasive Bunch Shape Monitor at GSI High Current LINAC

background, linac, ion, detector

421

B. Zwicker, O.K. Kester
IAP, Frankfurt am Main, Germany
C. Dorn, P. Forck, O.K. Kester, P. Kowina, B. Zwicker
GSI, Darmstadt, Germany

Funding: Supported by EU-Project CRISP, WP3 T1 ‘Non-intercepting Bunch Shape Monitors‘
At the heavy ion LINAC at GSI, a novel scheme of non-invasive Bunch Shape Monitor has been tested with several ions beam at 11.4 MeV/u and beam current in the range from 80 μA to 1000 μA. Caused by the beam impact on the residual gas, secondary electrons are liberated. These electrons are accelerated by an electrostatic field, transported through a sophisticated electrostatic energy analyzer and an rf-deflector, acting as a time-to-space converter. Finally a MCP amplifies the electrons and the electron distribution is detected by a CCD camera. For the applied beam settings this Bunch Shape Monitor is able to obtain longitudinal profiles down to of 250 ps RMS width with an RMS resolution of 34 ps, corresponding to 0.5° of the 36 MHz acceleration frequency. Systematic parameter studies, for the device were performed to demonstrate the applicability and to determine the achievable resolution. The background contribution, as orginated by x-rays, are investigated.

Poster TUPD07 [4.425 MB]

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TUPD09

Vacuum Improvement of Bunch Shape Monitor for J-PARC Linac

vacuum, target, high-voltage, linac

430

A. Miura, Y. Kawane, N. Ouchi
JAEA/J-PARC, Tokai-mura, Japan
T. Miyao
KEK, Ibaraki, Japan

During the shutdown in summer 2012, we installed three BSMs (Bunch Shape Monitors) at the upstream of the ACS (Annular Coupled Structure Linac) section in order to perform longitudinal matching. ACS cavities were installed in summer 2013 to upgrade the Linac energy from 181 MeV to 400 MeV. Prior to the ACS installation, BSMs were installed and the beam commissioning of the BSMs has been conducted after the summer shutdown in 2012. During the BSM measurements, a problem of the degradation in vacuum conditions was found. One reason for this problem is the dark current resulting in the desorption of absorbed gas molecules. And another reason is the outgas released from materials when the high voltage and RF power are supplied for the electro-static lens and RF deflector, respectively. In order to solve this problem, BSMs were dismounted from the beam line and the off-line baking operations with outgas analysis had been performed to avoid the degradation of the vacuum. As the result of the gas analysis, we found that the outgas contains some heavy hydrocarbons. After these heavy hydrocarbon gaseous were removed and the vacuum level improved for about one order, we completed off-line baking. We will install all three BSMs in at the upstream of the ACS again with the additional vacuum pumps. This paper describes the vacuum degradation of the BSMs, how to conduct the baking operation for BSMs and its results. The improved set-ups of the vacuum are also introduced.

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TUPD11

LANSCE 1L Harp Data Acquisition System Upgrade

data-acquisition, FPGA, software, hardware

438

J.D. Sedillo, J.D. Gilpatrick, J.D. Nguyen
LANL, Los Alamos, New Mexico, USA
M.E. Gruchalla
URS, Albuquerque, New Mexico, USA

The 1L harp is the last beam diagnostic preceding LANSCE’s 1L Target, the neutron source of LANSCE’s Lujan Center, and consists of two orthogonal planes of stationary sense wires for monitoring the beam distribution prior to its arrival at the target. A new data acquisition system has been developed for the 1L harp that features a National Instruments CompactRIO contained within a BiRIO chassis hosting electronic circuits for signal conditioning and a new feature for sense wire integrity monitoring. Hardware design, software architecture, and preliminary data acquisition results will be described.

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TUPD12

Development of Non-Invasive Electron Beam Position Monitor Based on Coherent Diffraction Radiation from a Slit

radiation, target, detector, linac

442

Y. Taira, R. Kuroda, M. Tanaka, H. Toyokawa
AIST, Tsukuba, Ibaraki, Japan
K. Sakaue
Waseda University, Tokyo, Japan
H. Tomizawa
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

Funding: This work was supported by Grants-in-Aid for Scientific Research (26246046).
Diffraction radiation (DR), which is closely related to transition radiation, is emitted when an electron passes near an edge or interface between two media with different dielectric constants. Theoretical and experimental investigation of DR is widely performing for a non-intercepting electron beam diagnostic. We have developed an electron bunch length and a beam position monitor using a coherent diffraction radiation (CDR), which is in the range of sub-millimeter wavelength. The frequency spectrum of CDR depends on a form factor expressed as the Fourier transform of the longitudinal particle distribution. We have measured the spatial intensity distribution of CDR emitted from the metallic edge with a terahertz camera. Total intensity passing through band pass filters (BPFs) was decreased as the transmission frequency of BPFs is increased up to 6 THz. The result indicates that the bunch length is few hundreds of femtosecond. A detailed data analysis is now performing. On the other hand, we have measured the intensity distribution of CDR emitted from the metallic rectangular slit. Bow-tie intensity distribution, aligned along the perpendicular direction to the slit edge, was measured with the terahertz camera. Moreover, when the electron beam did not pass through the center of the slit, an asymmetrical intensity distribution appeared. This asymmetry is due to the pre-wave zone effect. In short, we can found the beam position to the slit by measuring the asymmetry. In this conference, we will present the experimental results.

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TUPD16

Development of the Transverse Beam Profile Monitors for the PAL-XFEL

diagnostics, radiation, vacuum, target

452

I.Y. Kim, J.Y. Choi, H. Heo, H.-S. Kang, C. Kim, G. Mun, B.G. Oh, S.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

The PAL-XFEL is an X-ray free electron laser under construnction at the Pohang Accelerator Laboratory (PAL), Korea. In the PAL-XFEL, the electron beam can make coherent optical transition radiation (COTR) due to the microbunching instability in the compressed electron beam. In order to obtain transverse beam profiles without the COTR problem, we are developing scintillating screen monitors (with the geometric suppress method) and wire scanners. In this paper, we report test results at the test facility and progress in the development of the screen monitor and the wire scanner for the PAL-XFEL.

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TUPD24

Installation of a Beam Loss Monitoring System at the S-DALINAC*

controls, EPICS, radiation, monitoring

468

L.E. Jürgensen, U. Bonnes, C. Burandt, M. Fischer, F. Hug, T. Kürzeder, N. Pietralla, R. Stegmann, M. Steinhorst
TU Darmstadt, Darmstadt, Germany

Funding: *Work supported by the BMBF through 05K13RDA
The S-DALINAC is the superconducting linear accelerator of the Institut für Kernphysik at Technische Universität Darmstadt. It delivers an electron beam with energies up to 130 MeV. In order to get a short-time response about occurring beam losses and their locations a new system was tested and installed. The setup is based on beam loss monitors of Bergoz company using two pin-diodes to record primary electrons as well as secondary radiation in a coincidence set-up. The readout is done using a self-developed system of a supply unit including differential line-drivers and fast counting cards compatible to our EPICS-based control system. We will report on the installation of the whole system and its first commissioning as well as on the future use of the system for experiments on threshold currents for transverse beam break up.

Poster TUPD24 [1.661 MB]

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WEIXB1

LCLS Beam Diagnostics

undulator, diagnostics, cavity, laser

475

H. Loos
SLAC, Menlo Park, California, USA

Funding: Work supported by DOE contract DE-AC03-76SF00515
An extensive set of beam diagnostics has been one of the factors in the successful commissioning and operation of the Linac Coherent Light Source (LCLS) x-ray FEL over the last seven years. The originally developed and installed diagnostics were geared towards measuring the electron beam parameters of the LCLS design specifications. Since then, a number of improved and new diagnostics have been implemented to accommodate a much wider range of beam parameters and to overcome the challenges of diagnostics for a high brightness electron beam. Plans for the diagnostics of the LCLS-II project with its high repetition rate and high beam power and ongoing developments will also be discussed.

Slides WEIXB1 [4.408 MB]

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WECZB3

Measurement of Beam Losses Using Optical Fibers at the Australian Synchrotron

detector, synchrotron, beam-losses, emittance

515

E. Nebot Del Busto, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
M.J. Boland
ASCo, Clayton, Victoria, Australia
M.J. Boland, R.P. Rassool
The University of Melbourne, Melbourne, Victoria, Australia
E.B. Holzer, M. Kastriotou, E. Nebot Del Busto
CERN, Geneva, Switzerland
P.D. Jackson
University of Adelaide, Adelaide, Australia
J. Schmidt
Albert-Ludwig Universität Freiburg, Freiburg, Germany
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The unprecedented requirements that new machines are setting on their diagnostic systems are leading to the development of a new generation of devices with large dynamic range, sensitivity and time resolution. Beam loss detection is particularly challenging due to the large extension of new facilities that need to be covered with localized detectors. Candidates to mitigate this problem consist of systems in which the sensitive part of the radiation detectors can be extended over the long distances of beam lines. In this document, we study the feasibility of a beam loss monitor (BLM) system based on optical fibers as an active detector for an electron storage ring. The Australian Synchrotron (AS) comprises a 216m ring that stores electrons up to 3GeV. The Accelerator has recently claimed the world record lowest transverse emittance (below 1 pm rad). Ultra low transverse sizes and large amounts of synchrotron radiation provide an environment very similar to that expected in the CLIC damping rings. A qualitative benchmark of beam losses under damping ring-like conditions is presented here. A wide range of beam loss rates can be achieved by modifying the bunch charge, horizontal/vertical coupling and dynamic aperture as well as via beam scrapers. The controlled beam losses are observed by means of the Cherenkov light produced in a 365 um core Silica fiber. The output light is coupled to different types of photo sensors namely: Multi Pixel Photon Counters (MPPCs), standard PhotoMulTiplier (PMT) tubes and Avalanche PhotoDiodes (APD). A detailed comparison of the sensitivities and time resolution obtained with the different read-outs are discussed in this contribution.

Slides WECZB3 [2.755 MB]

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WEPF05

Simulation of the Beam Dump for a High Intensity Electron Gun

simulation, gun, scattering, collider

536

A. Jeff, S. Döbert, T. Lefèvre
CERN, Geneva, Switzerland
A. Jeff
The University of Liverpool, Liverpool, United Kingdom
K. Pepitone
CEA, LE BARP cedex, France

The CLIC Drive Beam is a high-intensity pulsed electron beam. A test facility for the Drive Beam electron gun will soon be commissioned at CERN. In this contribution we outline the design of a beam dump / Faraday cup capable of resisting the beam’s thermal load. The test facility will operate initially up to 140 keV. At such low energies, the electrons are absorbed very close to the surface of the dump, leading to a large energy deposition density in this thin layer. In order not to damage the dump, the beam must be spread over a large surface. For this reason, a small-angled cone has been chosen. Simulations using geant4 have been performed to estimate the distribution of energy deposition in the dump. The heat transport both within the electron pulse and between pulses has been modelled using finite element methods to check the resistance of the dump at high repetition rates. In addition, the possibility of using a moveable dump to measure the beam profile and emittance is discussed.

Poster WEPF05 [0.224 MB]

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WEPF07

Optimization of a Short Faraday Cup for Low-Energy Ions Using Numerical Simulations

ion, diagnostics, simulation, linac

544

A.G. Sosa, E. Bravin, E.D. Cantero
CERN, Geneva, Switzerland
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: CATHI is a Marie Curie Initial Training Network funded by the European Commission under Grant Agreement Number PITN-GA-2010-264330.
ISOLDE, the heavy-ion facility at CERN is undergoing a major upgrade with the installation of a superconducting LINAC that will allow post-acceleration of ion beams up to 10 MeV/u. In this framework, customized beam diagnostics are being developed in order to fulfill the design requirements as well as to fit in the compact diagnostic boxes foreseen. The main detector of this system is a compact Faraday cup that will measure beam intensities in the range of 1 pA to 1 nA. In this contribution, simulation results of electrostatic fields and particle tracking are detailed for different Faraday cup prototypes taking into account the energy spectrum and angle of emission of the ion-induced secondary electrons.

Poster WEPF07 [1.282 MB]

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WEPF08

Dosimetry of Pulsed Beams in Proton Therapy

proton, experiment, ion, high-voltage

548

J. van de Walle, Y. Claereboudt, G. Krier, D. Prieels
IBA, Louvain-la-Neuve, Belgium
G. Boissonnat, J. Colin, J.-M. Fontbonne
LPC, Caen, France

Ion Beam Applications (IBA) has developed in recent years the ProteusONE proton therapy system, which aims at reducing the cost and footprint of proton therapy systems, making them affordable and accessible to more patients worldwide. The heart of the ProteusONE system is a super conducting synchro-cyclotron (S2C2), which provides short (10 μs) proton bunches at 1 kHz. This is in contrast to the proton therapy systems including the IBA Cyclone230, which delivers a continuous beam. Nevertheless, the same average dose rates are provided by both systems. As a consequence, the instantaneous dose rates with the S2C2 are much higher and recombination losses in the large area beam diagnostics and dosimetry devices become non negligible. Since the proton charge which is send to a patient should be measured with high precision, these recombination losses have to be addressed carefully. In this work, a large area (30x30 cm²) and large gap (>3 mm) ionization chamber (IC) is presented which allows to quantify recombination losses in each beam pulse on-line. The principle is based on the introduction of two ionization volumes in series with slightly different gap sizes. The ratio of detected charges in both IC's is the basic observable which is used to recalculate the efficiency of each IC. The principle of this so-called "asymmetric ionization chamber" (AIC) was tested with beam from the S2C2 prototype. The results show that the efficiency can be re-calculated to 0.5% precision for voltages higher than 1000 V. Together with the experimental results, the theoretical background of the recombination losses will be discussed and it will be shown how this theory is applied in a robust and simple way to correct for these losses in the proton therapy system.

Poster WEPF08 [0.999 MB]

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WEPF09

Introduction to the Test Result of Turbo-ICT in PAL-ITF

monitoring, laser, diagnostics, pick-up

553

H. J. Choi, M.S. Chae, H.-S. Kang, S.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) built a PAL-ITF (Injector Test Facility) at the end of 2012 to successfully complete PAL-XFEL (X-ray Free Electron Laser) in 2015. The PAL-ITF is equipped with various kinds of diagnostic equipment to produce high-quality electron bunches. The three main parameters that an injection testing facility should measure are charge, energy and emittance. Although ICT and Faraday Cup were installed to measure beam charge, the noise generated in a klystron modulator not only interrupted accurate measurement but prevented low charges under tens of pC from being measured. Due to the changes in the overall voltage level of ITF, integration of ICT measured value failed to maintain perfect accuracy in terms of methodology (measured value continuously changed by ± 5pC). Accordingly, to solve the noise problems and accurately measure the quantity of electron beam charge, Turbo-ICT was installed. This paper focuses on the processes and test result of electric bunch charge quantity measurements using Turbo-ICT.

Poster WEPF09 [2.807 MB]

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WEPF19

Fast Transverse Phase Space Measurement System for GunLab - A Compact Test Beamline for SRF Photoinjectors

emittance, quadrupole, SRF, gun

588

J. Völker, T. Kamps
HZB, Berlin, Germany

Superconducting radiofrequency photo electron injectors (SRF guns) are promising electron sources for the next generation of electron linear accelerators. The energy recovery linac (ERL) BERLinPro will employ a 1.5 cell 1.3 GHz SRF gun cavity with normal conducting high quantum efficiency photocathode to produce a 100mA CW electron beam with high brightness. We are currently working on a compact test beamline (GunLab) to investigate the properties of the electron beam and to optimize the drive laser as well RF parameters. The motivation for GunLab is to decouple the SRF gun development from the ERL development. The goal is to measure not only the complete 6 dimensional phase space of the extracted and accelerated bunches but also to investigate dark current and beam halo. In this paper we will discuss unique features of GunLab for the phase space measurements.

Poster WEPF19 [2.025 MB]

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WEPF21

Electron Cloud Density Measurements Using Resonant Microwaves at CesrTA

resonance, positron, storage-ring, photon

592

J.P. Sikora
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
S. De Santis
LBNL, Berkeley, California, USA

Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505.
Hardware has recently been installed in the Cornell Electron Storage Ring (CESR) to extend the capability of resonant microwave measurement of electron cloud density. Two new detector locations include aluminum beam-pipe in a dipole magnet and copper beam-pipe in a field free region. Measurements with both positron and electron beams are presented with both beams showing saturation of the electron cloud density in the aluminum chamber. These measurements were made at CESR which has been reconfigured as a test accelerator (CesrTA) with positron or electron beam energies ranging from 2 GeV to 5 GeV.

Poster WEPF21 [1.988 MB]

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WEPD04

High Position Resolution and High Dynamic Range Stripline Beam Position Monitor (BPM) Readout System for the KEKB Injector Linac Towards the SuperKEKB

linac, positron, alignment, rf-amplifier

637

R. Ichimiya, K. Furukawa, F. Miyahara, M. Satoh, T. Suwada
KEK, Ibaraki, Japan

The SuperKEKB accelerator is now being upgraded to bring the world highest luminosity (L=8x10³⁵/cm²/s). Hence, the KEKB injector linac has to produce low emittance and high charge electron (20 mm mrad, 7 GeV/c², 5 nC) and positron (20 mm mrad, 4 GeV/c², 4 nC) beam, respectively. In order to achieve these criteria, the accelerator structure has to be aligned within 0.1 mm position error. Since BPMs are essential instruments for beam based alignment (BBA), it is required to have one magnitude better position resolution to get enough alignment results. We have begun to develop high position resolution BPM readout system with narrow bandpass filters (fc = 180 MHz) and 250 MSa/s 16-bit ADCs. It handles two bunches with 96 ns interval separately and has a dynamic range from 0.1 nC to 10 nC. To compensate circuit drift, two calibration (x-direction and y-direction) pulses are output to the BPM electrodes between beam cycles (20 ms). Since it needs to achieve not only high position resolution but also good position accuracy, overall non-linearity within ±0.02 dB is required and the system has to have more than ±5 mm accurate position range. We confirmed the system performance with a 3-BPM resolution tests at KEK Injector Linac and it turned out that the system has 3 μm position resolution. We plan to install this system during 2015 summer shutdown.

Poster WEPD04 [0.828 MB]

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WEPD08

Beam Jitter Spectra Measurements of the APEX Photoinjector

laser, gun, feedback, timing

652

H.J. Qian, J.M. Byrd, L.R. Doolittle, Q. Du, D. Filippetto, G. Huang, F. Sannibale, R.P. Wells
LBNL, Berkeley, California, USA
J. Yang
TUB, Beijing, People's Republic of China

High repetition rate photoinjectors such as the APEX at LBNL are one of the enabling technologies for next generation MHz XFELs. Due to the higher repetition rate, a wider bandwidth is available for feedback systems to achieve ultra-stable beam performance. In a first step to improve APEX beam stability, the noise power spectra of the APEX laser beam and electron beam are characterized in terms of intensity and timing. Possible feedback systems are also discussed.

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THIXB1

Commissioning of the FLASH2 Electron Beam Diagnostics in Respect to its use at the European XFEL

diagnostics, electronics, undulator, vacuum

712

N. Baboi, D. Nölle
DESY, Hamburg, Germany

This report presents the first operation experience of the electron beam diagnostics at FLASH2. FLASH2 is a new undulator line at the FLASH linac at DESY. Most electron beam diagnostics installed, like the beam loss monitors, cavity beam position monitors, toroids, beam halo monitors, have been designed for the European XFEL, and will provide operational experience beforehand. A few systems, as for example the button beam position monitors and the ionization chambers, have been developed for FLASH. The controls use the new MTCA.4 standard. Both linacs, FLASH and the European XFEL, require similar performance of the diagnostics systems. Many beam parameters are similar: bunch charge of 0.1 to 1 nC, pulse repetition frequency of 10 Hz, while others will be more critical at the XFEL than the ones currently used at FLASH, like the bunch frequency of up to 4.5 MHz. versus 1 MHz. The commissioning of FLASH2 and its diagnostics is ongoing. The beam monitors have accompanied the first beam through the linac, fine tuning for some systems is still to be done. The achieved performance will be presented in view of their use at the European XFEL.

Slides THIXB1 [3.875 MB]

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THCXB1

Cross-Calibration of Three Electron Cloud Density Detectors at CesrTA

simulation, detector, photon, resonance

722

J.P. Sikora, J.R. Calvey, J.A. Crittenden
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467, and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505.
Measurements of electron cloud density using three detector types are compared under the same beam conditions at the same location in the Cornell Electron Storage Ring (CESR). Two of the detectors sample the flux of cloud electrons incident on the beam-pipe wall. The Retarding Field Analyzer (RFA) records the time-averaged charge flux and has a retarding grid that can be biased to select high energy electrons. The Shielded Button Electrode (SBE) samples the electron flux without a retarding grid, acquiring signals with sub-nanosecond resolution. The third detector uses resonant microwaves and measures the electron cloud density within the beam-pipe through the cloud-induced shift in resonant frequency. The analysis will include comparison of the output from POSINST and ECLOUD simulations of electron cloud buildup. These time-sliced particle-in-cell 2D modeling codes – simulating photoelectron production, secondary emission and cloud dynamics – have been expanded to include the electron acceptance of the RFA and SBE detectors in order to model the measured signals. The measurements were made at the CESR storage ring, which has been reconfigured as a test accelerator (CesrTA) providing electron or positron beams ranging in energy from 2 GeV to 5 GeV.

Slides THCXB1 [3.240 MB]

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