Keyword: diagnostics
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MOOA02 Beam Instrumentation for X-ray FELs cavity, FEL, feedback, undulator 1
 
  • H. Loos
    SLAC, Menlo Park, California, USA
  
  Funding: This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC03-76SF00515.
The performance of X-ray Free-electron lasers depends strongly on the achieved quality of the high brightness electron beam and its shot by shot stability. The requirements and challenges of the instrumentation needed to tune and optimize such electron beams will be discussed. Of particular interest are measurements of the beam orbit, emittance, energy, and bunch length and the different measurement techniques for these transverse and longitudinal beam parameters and their implementation for routine operation will be addressed in detail, particularly the necessary instrumentation to fulfill different user requirements in terms of beam energy and bunch length. Specific requirements for the initial commissioning, routine optimization and feedback applications will be presented as well. 		 
slides icon Slides MOOA02 [2.114 MB]  
 
MOPD04 RHIC Electron Lens Test Bench Diagnostics electron, ion, gun, solenoid 38
 
  • D.M. Gassner, E.N. Beebe, W. Fischer, X. Gu, K. Hamdi, J. Hock, C. Liu, T.A. Miller, A.I. Pikin, P. Thieberger
    BNL, Upton, Long Island, New York, USA
  
  An Electron Lens system will be installed in RHIC to increase luminosity by counteracting the head-on beam-beam interaction. The proton beam collisions at the two experimental locations will introduce a tune spread due to a difference of tune shifts between small and large amplitude particles. A low energy electron beam will be used to improve luminosity and lifetime of the colliding beams by reducing the betatron tune shift and spread. In preparation for the Electron Lens installation next year, a test bench facility will be used to gain experience with all sub-systems. This paper will discuss the diagnostics related to measuring the electron beam parameters.  
 
MOPD05 Beam Diagnostic Layout for SIS100 at FAIR ion, pick-up, proton, beam-losses 41
 
  • M. Schwickert, P. Forck, T. Hoffmann, P. Kowina, H. Reeg
    GSI, Darmstadt, Germany
  
  The SIS100 heavy ion synchrotron will be the central machine of the FAIR (Facility for Antiprotons and Ions Research) project currently designed at GSI. The unique features of SIS100, like e.g. the acceleration of high intensity beams of 2.5·1013 protons and 5·1011 Uranium ions near the space charge limit, the anticipated large tune spread, extreme UHV conditions of the cryogenic system for superconducting magnets and fast ramp rates of 4 T/s, make challenging demands on the beam diagnostic components. This contribution describes the conceptual design for SIS100 beam diagnostics and reports on the present status of prototype studies. Exemplarily the progress concerning beam position monitors, beam current transformers and beam-loss monitors is presented.  
 
MOPD07 Newly Installed Beam Diagnostics at the Australian Synchrotron injection, booster, synchrotron, linac 47
 
  • E.D. van Garderen, M.J. Boland, G. LeBlanc, B. Mountford, A. Rhyder, A. C. Starritt, A. Walsh, K. Zingre
    ASCo, Clayton, Victoria, Australia
  
  The Australian Synchrotron (AS) is aiming at implementing Top-Up operations in 2012. To reduce costs only one of the two klystrons in the linac will be used. The electron beam in the linac will only be accelerated to 80 MeV, instead of 100 MeV achieved currently. The injection system will need to be recommissioned. The beam position monitors in the booster have been upgraded and YAG:Ce screens have been added to the booster-to-storage ring (BTS) transfer line. In addition the injection efficiency will be optimized and monitored. For this purpose another Fast Current Transformer has also been installed at the end of the BTS.  
 
MOPD08 Beam Diagnostics in the J-PARC Linac for ACS Upgrade linac, pick-up, acceleration, simulation 50
 
  • A. Miura, S. Sato
    JAEA/J-PARC, Tokai-mura, Japan
  • Z. Igarashi, M. Ikegami, T. Miyao, T. Toyama
    KEK, Ibaraki, Japan
  • T. Tomisawa
    JAEA/LINAC, Ibaraki-ken, Japan
  
  J-PARC had developed the beam diagnostic devices for the current J-PARC linac and has used them since the operation start. J-PARC linac began the energy upgrade project since 2009 and 21 ACS cavities will be installed. In this project, many cavities and related devices are newly installed in the ACS section and its downstream part. Because the beam parameters are updated, new beam diagnostic devices are fabricated and current diagnostic devices are developed. Beam position monitors (BPM) are newly designed and fabricated, based on the computer simulation and bench test. Because the gas proportional BLMs as the current BLM are sensitive to background noise of X-ray emitted from RF cavities, it is difficult to recognize real beam loss. We need to subtract an X-ray noise from the signal from BLM, another candidate BLMs have been tried to measure the beam loss. In addition, the bunch shape monitor for the longitudinal tuning has been developed in the corroboration with the institute for nuclear research, Russia. In this paper, we describe the new developed devices and their development process, especially for beam loss monitor and the developing bunch shape monitor.  
 
MOPD09 Electron Beam Diagnostics for FLASH II undulator, electron, radiation, laser 53
 
  • N. Baboi, D. Nölle
    DESY, Hamburg, Germany
  
  Up to now, the FLASH linac serves one SASE (Self-Amplified Spontaneous Emission) undulator. The radiation produced can be guided to one of 5 beamlines in the experimental hall. In order to increase the availability of the machine, an extension, FLASH II, will be built in the next few years. A second undulator section will be built to generate SASE light. A HHG (High Harmonic Generation) laser will alternatively be used to produce seeded radiation in the undulators. The electron beam diagnostics in FLASH II has to enable the precise control of the beam position, size, timing, as well as the overlap of the electron beam with the HHG laser. The losses have to be kept under control, and the beam has to terminate safely in the beam dump. In comparison to FLASH, which was designed to run with rather high charge, the dynamic range of the diagnostics has to be between 0.1 to 1 nC, similar to the European XFEL. This paper gives an overview of the diagnostics for FLASH II.  
 
MOPD11 High Resolution BPM Upgrade for the ATF Damping Ring at KEK damping, closed-orbit, injection, controls 59
 
  • N. Eddy, C.I. Briegel, B.J. Fellenz, E. Gianfelice-Wendt, P.S. Prieto, R. Rechenmacher, A. Semenov, D.C. Voy, M. Wendt, D.H. Zhang
    Fermilab, Batavia, USA
  • N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  
  Funding: Work is supported by the joint high energy physics research program of Japan-USA, and by FNAL, operated by Fermi Research Alliance LLC under contract #DE-AC02-07CH11359 with the US Dept. of Energy.
A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility (ATF) damping ring has been accomplished, carried out by a KEK/FNAL/SLAC collaboration under the umbrella of the global ILC R&D effort. The upgrade consists of a high resolution, high reproducibility read-out system, based on analog and digital down-conversion techniques, digital signal processing, and also implements a new automatic gain error correction schema. The technical concept and realization as well as results of beam studies are presented. 		 
 
MOPD23 Photon BPM Electronics Development at Taiwan Light Source photon, injection, feedback, controls 95
 
  • P.C. Chiu, J. Chen, Y.K. Chen, K.T. Hsu, K.H. Hu, C.H. Kuo
    NSRRC, Hsinchu, Taiwan
  
  Photon BPMs are very useful for photon beam position and stability observation. There are several kinds of photon BPMs and electronics with different design installed at beamline front-ends at the Taiwan Light Source. To provide a better integration and efficient usage of the photon BPM, a commercial BPM electronics - Libera Photon was chosen for an integral solution and has showed at least one micron performance for several months of testing. In this report, the installation process and testing results of the photon BPM will be presented.  
poster icon Poster MOPD23 [0.595 MB]  
 
MOPD36 Development of a Silicon Detector Monitor for the Superconducting Upgrade of the REX-ISOLDE Heavy-Ion Linac at CERN linac, cavity, ion, rfq 131
 
  • F. Zocca
    IEM, Madrid, Spain
  • E. Bravin, M.A. Fraser, D. Voulot, F.J.C. Wenander, F. Zocca
    CERN, Geneva, Switzerland
  • M. Pasini
    Instituut voor Kern- en Stralingsfysica, K. U. Leuven, Leuven, Belgium
  
  A silicon detector monitor has been developed and tested in the frame of the beam diagnostics development program for the HIE-ISOLDE superconducting upgrade of the REX-ISOLDE heavy-ion linac at CERN. The monitor is intended for beam energy and timing measurements as well as for phase scanning of the superconducting cavities. Tests have been performed with a stable ion beam, composed of carbon, oxygen and neon ions accelerated to energies from 300 keV/u to 2.85 MeV/u. The silicon detector was placed directly in the beam line and tested with a beam which was strongly attenuated to simulate the single particle detection regime for which the monitor is intended to finally function. The energy measurements performed allowed for beam spectroscopy and ion identification with a resolution of 3%. The principle of cavity phase scanning was also demonstrated with the REX 7-gap resonator thanks to the accurate peak energy identification. The time structure of the beam, characterized by a bunch period of 9.87 ns, was measured with a resolution better than 200 ps. This paper describes the results from all these tests as well as providing details of the detector.  
 
MOPD38 1-MHz Line Detector for Intra-bunch-train Multichannel Feedback laser, radiation, electron, feedback 137
 
  • L. Kotynia, D.R. Makowski, A. Mielczarek, A. Napieralski
    TUL-DMCS, Łódź, Poland
  • C. Gerth, T. Jezynski, H. Schlarb, B. Schmidt, B. Steffen
    DESY, Hamburg, Germany
  
  Funding: This work is partly supported by IRUVX-PP an EU co-funded project under FP7 (Grant Agreement 211285).
The measurement and control of the electron bunch length is one of the key diagnostics in linac-based free-electron lasers to reach the required peak current in the electron bunches. In order to use the multi-channel signals from longitudinal bunch shape measurements for intra train feedback for the European XFEL, line readout rates in the MHz range and low latencies are required, which is far more than commercial multichannel radiation detectors (line cameras) can provide. The paper presents a 256 channel detector that allows analyzing optical or infrared radiation with 1 MHz rate and a few microseconds latency using photodiode arrays, as needed for synchrotron light monitors, electro-optical bunch length measurements, or other laser based diagnostics. The proposed architecture aims at high frequency readout with low latency by using a multichannel electronic front-end designed for HEP, combined with Si or InGaAs detector arrays with very fast response time, and a low-latency data acquisition system. Currently the device is at the conceptual design stage. 		 
poster icon Poster MOPD38 [3.262 MB]  
 
MOPD40 Beam Measurements with Visible Synchrotron Light at VEPP-2000 Collider controls, collider, electron, positron 140
 
  • Yu. A. Rogovsky, D.E. Berkaev, I. Koop, A.N. Kyrpotin, I. Nesterenko, A.L. Romanov, Y.M. Shatunov, D.B. Shwartz
    BINP SB RAS, Novosibirsk, Russia
  
  This paper describes beam diagnostics at VEPP-2000 collider, based on visible synchrotron light analysis. These beam instruments include: SR beamline and optics; acquisition tools and high resolution CCD cameras distributed around the storage ring to measure the transverse beam profile and its position in vacuum chamber; photomultiplier tubes (PMT) which enables beam current measurements. Some applications of these measurement systems and their measurement results are presented.  
poster icon Poster MOPD40 [0.599 MB]  
 
MOPD44 Self Testing Functionality of the LHC BLM System high-voltage, monitoring, injection, collider 152
 
  • J. Emery, B. Dehning, E. Effinger, A. Nordt, C. Zamantzas
    CERN, Geneva, Switzerland
  
  Reliability concerns have driven the design of the LHC BLM system throughout its development, from the early conceptual stage right through the commissioning phase and up to the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to insure that the system status after each test is "as good as new". This checks the electrical part of the detectors (ionisation chamber or secondary emission monitor), their cable connections to the front-end electronics, the connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks proved invaluable in finding non-conformities caused by unexpected failures. This paper will describe these checks in detail, commenting on the latest performance and the typical non-conformities detected. A statistical analysis of the LHC BLM system will also be presented to show the evolution of the various system parameters.  
poster icon Poster MOPD44 [2.068 MB]  
 
MOPD48 Optical Electron Beam Diagnostics for Relativistic Electron Cooling Devices electron, laser, scattering, photon 158
 
  • T. Weilbach
    HIM, Mainz, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • J. Dietrich
    FZJ, Jülich, Germany
  
  New magnetized high energy coolers like the one proposed for the High Energy Storage Ring (HESR) at the Facility for Antiproton and Ion Research (FAIR) have specific demands on the diagnostic of the electron beam. Due to high voltage breakdowns they only allow a very small beam loss so non-invasive beam diagnostic methods are necessary. For beam profile measurement a system based on beam induced fluorescence (BIF) was designed and is under installation at the 100 keV polarized test setup at the Mainzer Mikrotron (MAMI) at the moment. For the diagnostic of other observables of the cooling beam, like the electron beam energy or the electron temperature, a Thomson scattering experiment is planned at the same setup. The planned experiments for the beam profile measurement are presented and the challenges of the Thomson scattering method are discussed.  
 
MOPD54 Commissioning Results of the Photon-Electron Diagnostic Unit at sFLASH laser, electron, undulator, FEL 173
 
  • J. Bödewadt, E. Hass, J. Roßbach
    Uni HH, Hamburg, Germany
  
  Funding: Supported by the Federal Ministry of Education and Research of Germany under contract 05 ES7GU1
Recently a seeded free-electron laser operating in the extreme ultra-violet (XUV) spectral range was installed and commissioned at the free-electron laser FLASH. The seed beam is generated by higher harmonics of near infrared laser pulses. A dedicated transport system guides the radiation into the electron accelerator environment. Within the seed undulator section compact diagnostic units were installed to control the transverse overlap of the photon and the electron beam. These units contain a BPM, horizontal and vertical wire scanners and an OTR screen for the electron diagnostic. A Ce:YAG screen and a MCP readout for the wire scanner are used to measure the photon beam position. This paper presents the commissioning results and the performance of the diagnostic units. 		 
 
MOPD55 SEM-GRID Prototype Electronics using Charge-Frequency-Converters controls, ion, radiation, monitoring 176
 
  • M. Witthaus, J. Adamczewski-Musch, H. Flemming, J. Frühauf, S. Löchner, H. Reeg, P. Skott
    GSI, Darmstadt, Germany
  
  A prototype system using an ASIC equipped with 8 Charge-to-Frequency Converters (CFC) was developed in collaboration between the Beam Diagnostics and Experiment Electronics Department at GSI. The maximum sensitivity is 250 fC per output pulse. It will serve as an economic alternative for the readout electronics of Secondary Electron Monitor (SEM)profile grids or comparable beam diagnostic devices like Multi-Wire Proportional Chambers (MWPC). The goal of this contribution is to report on a detailed performance test under real beam conditions at GSI beam lines. A 32-channel electronics is connected to different beam profile SEM-grids at a LINAC beam line and tested with various beam conditions. Transversal beam profiles with a time resolution down to the microsecond range have been recorded successfully. Beam profiles recorded with the new CFC-board and the old standard trans-impedance amplifiers agreed well. Further measurements were done with Multi-Wire Proportional Chamber. Therefore the prototype was extended to 64-input channels recently.  
poster icon Poster MOPD55 [1.344 MB]  
 
MOPD60 Beam Induced Fluorescence (BIF) Monitors as a Standard Operating Tool controls, ion, photon, heavy-ion 185
 
  • C.A. Andre, F. Becker, H. Bräuning, P. Forck, R. Haseitl, R. Lonsing, B. Walasek-Höhne
    GSI, Darmstadt, Germany
  
  For high current operation at the GSI Heavy Ion UNILAC non intercepting methods for transverse beam profile determination are required. The Beam Induced Fluorescence (BIF) Monitor, an optical measurement device based on the observation of fluorescent light emitted by excited gas molecules was brought to routine operation. Detailed investigations were conducted for various beam parameters to improve the electronics and the optical setup. Up to now, four BIF monitor stations (for detection of both, horizontal and vertical beam profiles) were installed at UNILAC and two additional setups are planned. This contribution reports on first upgrades of the BIF monitors with a Siemens PLC for FESA-based slow controls and hardware protection procedures. The versatile control and display software ProfileView is presented as an easy-to-use and stable beam diagnostic tool for the GSI operating team.  
poster icon Poster MOPD60 [3.060 MB]  
 
MOPD62 Storage Ring Injector Diagnostics using Synchrotron Radiation injection, emittance, radiation, booster 191
 
  • A.F.D. Morgan, C.A. Thomas
    Diamond, Oxfordshire, United Kingdom
  • R. Bartolini
    JAI, Oxford, United Kingdom
  
  The state of the Diamond injector can be passively monitored using beam profile measurements of synchrotron radiation from bending magnets. This provides us with information on the characteristics of the beam injected into the storage ring. Using a numerical fit we are able to retrieve key parameters like beam position, size and tilt angle from every shot. This enables us to gather longer term trends to monitor for any changes during top-up operation in order to better understand any variability of the injector. We present here the study and the analysis performed with this diagnostic with the results from several months of operation.  
poster icon Poster MOPD62 [0.451 MB]  
 
MOPD65 Sensitivity Optimization of the Standard Beam Current Monitors for XFEL and FLASH II pick-up, monitoring, impedance, ion 197
 
  • M. Werner, J. Lund-Nielsen, Re. Neumann, N. Wentowski
    DESY, Hamburg, Germany
  
  There is a tendency to operate 4th generation SASE driven light sources at very low charge in order to further shorten the pulse length. Therefore the operation range of XFEL and FLASH II was extended to a charge range of as low as 20 pC to 1 nC. For a reliable charge measurement down to 20 pC, a low noise design of the signal chain from the monitor head to the digitizing ADC is necessary. This paper describes the steps taken in order to increase the sensitivity and dynamic range of the monitors currently used in the FLASH accelerator, and the basic theoretical background will be explained. Finally, first results are presented.  
poster icon Poster MOPD65 [0.768 MB]  
 
MOPD69 Tune Measurements with High Intensity Beams at SIS-18 injection, acceleration, monitoring, emittance 206
 
  • R. Singh, P. Forck, W. Kaufmann, P. Kowina
    GSI, Darmstadt, Germany
  • R. Singh
    TEMF, TU Darmstadt, Darmstadt, Germany
  
  Funding: This work is supported by DITANET (novel DIagnostic Techniques for future particle Accelerators: A Marie Curie Initial Training NETwork), Project Number ITN-2008-215080
To achieve high current operation close to the space charge limit in a synchrotron, a precise tune measurement during a full accelerating cycle is required. A tune measurement system that was recently commissioned at GSI synchrotron SIS-18 allows for online evaluation of the actual tune. This system consists of three distinct parts; an exciter which provides power to excite coherent betatron oscillations of the beam. The BPM signals thus induced are digitized by fast ADCs at 125 MSa/s and then the post processing electronics integrates the data bunch by bunch to obtain one position value per bunch. Subsequently base band tune is determined by Fourier transformation of the position data. The tune variation during acceleration for various beam conditions was measured using this system and is discussed. A detailed investigation of the incoherent tune shift was conducted with Uranium ion beams at the injection energy of 11.6 MeV/u. The results show the influence of beam current on the tune spectrum. In addition, the effects of the measurement method on the beam emittance and beam losses are discussed. 		 
 
MOPD86 Development of FESA-based Data Acquisition and Control for FAIR controls, synchrotron, high-voltage, power-supply 248
 
  • R. Haseitl, H. Bräuning, T. Hoffmann, K. Lang, R. Singh
    GSI, Darmstadt, Germany
  
  GSI has selected the CERN Front End Software Architecture (FESA) to operate future beam diagnostic devices for the upcoming FAIR facility. The FESA framework is installed and operational at the GSI site, giving equipment specialists the possibility to develop FESA classes for device control and data acquisition. This contribution outlines first developments of FESA-based systems for various applications. Prototype DAQ systems based on FESA are the BPM system of the synchrotron SIS18 with data rates up to 7 GBit/s and a large scaler setup for particle counters called LASSIE. FESA classes that address gigabit Ethernet cameras are used for video imaging tasks like scintillator screen observation. Control oriented FESA classes access industrial Programmable Logic Controllers (PLCs) for the slow control of beam diagnostic devices. To monitor temperatures and set fan speeds of VME crates, a class communicating over the CAN bus has been developed.  
poster icon Poster MOPD86 [3.137 MB]  
 
MOPD91 Pulse-By-Pulse X-ray Beam Monitor Equipped with Microstripline Structure electron, high-voltage, impedance, pick-up 260
 
  • H. Aoyagi, S. Takahashi
    JASRI/SPring-8, Hyogo-ken, Japan
  • H. Kitamura
    RIKEN/SPring-8, Hyogo, Japan
  
  Pulse-by-pulse measurement of X-ray beam is import issue for the 3rd generation light sources in order not only to stabilize X-ray beam in an experimental hutch but also to diagnose electron beam in a storage ring. A new pulse-by-pulse X-ray beam monitor equipped with microstripline structure has been developed. The detector head has the microstripline structure. The impedance of the detector head is matched to 50 ohm. Thermodynamics of the detector head is also well considered against severe heat load. The advantage of this monitor is that output signal is short and unipolar pulse, so front-end electronics can be simplified. The feasibility tests have been demonstrated at the X-ray beamline of SPring-8 in the term of (1) pulse intensity monitor, (2) pulse-by-pulse X-ray beam position monitor, and (3) the pulse-timing monitor. Then, we have improved the structure of the detector head in order to sophisticate the function as the pulse timing monitor. As a result, we successfully removed the ringing parts of output signal, and demonstrated that this monitor can be used as the timing monitor. We also describe a new scheme for beam diagnostics using this monitor.  
poster icon Poster MOPD91 [1.309 MB]  
 
MOPD92 Review of Recent Upgrades & Modernizations on Diagnostics in the ESRF Storage Ring and Injector booster, storage-ring, controls, vacuum 263
 
  • B. Joly, P. Arnoux, D. Robinson, K.B. Scheidt
    ESRF, Grenoble, France
  
  Over the last two years a number of upgrades and modernizations have been implemented on diagnostic tools in both the Injector system and the Storage Ring. Brand new diagnostic tools have also been added. In the Injector, a new Transfer Line current monitor has been installed, as well as four new ¼ λ Striplines equipped with Single-Pass Libera electronics. In the Storage Ring, a new Visible Light Mirror (VLM) system has replaced the original system that had been in place for more than 15 years. Also, the acquisition system for the DC Current Transformers has been upgraded with new hardware. Descriptions and results are presented on the improved reliability, sensitivity and resolution of these systems.  
 
MOPD93 Investigation of Diagnostic Techniques on a Nonneutral Plasma electron, plasma, space-charge, ion 266
 
  • K. Schulte, M. Droba, O. Meusel, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  
  Funding: Work supported by HIC for FAIR, BMBF No. 06FY90891.
Space charge lenses use a confined electron cloud for the focusing of ion beams. The focusing strength is given by the electron density whereas the density distribution influences the mapping quality of the space charge lens and is related to the confinement. The plasma parameters, loss as well as production mechanisms have a strong impact on plasma beam interactions. A scaled up space charge lens was constructed to investigate the properties of a nonneutral plasmas in detail. New non-interceptive diagnostic has been developed to characterize the collective behaviour of the confined nonneutral plasma in terms of an optimized lens design and parameters. Experimental results will be presented in comparison with numerical simulations. 		 
poster icon Poster MOPD93 [3.587 MB]  
 
TUOA02 Diagnostics during the ALBA Storage Ring Commissioning injection, synchrotron, kicker, storage-ring 280
 
  • U. Iriso, M. Alvarez, F.F.B. Fernandez, A. Olmos, F. Pérez
    CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
  
  The ALBA Storage Ring is a 3GeV 3rd Generation Synchrotron Light Source whose 1st phase commissioning took place in Spring 2011. The machine is equipped with 123 BPMs, striplines, several fluorescent screens, FCT and DCCT, 128 BLMs, and two front ends strictly used for electron beam diagnostics (pinhole and streak camera). This paper presents an overview of the Diagnostics elements installed in the machine and our experience during the commissioning.  
slides icon Slides TUOA02 [5.476 MB]  
 
TUOA03 The Fermilab HINS Test Facility and Beam Measurements of the Ion Source and 325 MHz RFQ rfq, proton, laser, linac 283
 
  • V.E. Scarpine, S. Chaurize, B.M. Hanna, S. Hays, J. Steimel, R.C. Webber, D. Wildman
    Fermilab, Batavia, USA
  
  Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
The Fermilab High Intensity Neutrino Source (HINS) project is intended to test new concepts for low-energy, high-intensity superconducting linacs. HINS initial design consists of a 50 KeV ion source, a 2.5 MeV Radiofrequency Quadrupole (RFQ) followed by room temperature and superconducting spoke resonator acceleration sections. At present, a proton ion source and the 325 MHz RFQ, followed by a beam diagnostics section, have been operated with beam. This paper will present the beam measurement results for the proton ion source and for the 325 MHz RFQ module. In addition, this paper will discuss the role of HINS as a test facility for the development of beam diagnostic instrumentation required for future high-intensity linacs. 		 
slides icon Slides TUOA03 [1.864 MB]  
 
TUOA04 Instrumentation for Machine Protection at FERMI@Elettra undulator, FEL, radiation, electron 286
 
  • L. Fröhlich, A.I. Bogani, K. Casarin, G. Cautero, G. Gaio, D. Giuressi, A. Gubertini, R.H. Menk, E. Quai, G. Scalamera, A. Vascotto
    ELETTRA, Basovizza, Italy
  • L. Catani, D. Di Giovenale
    INFN-Roma II, Roma, Italy
  
  FERMI@Elettra is a linac-driven free-electron laser currently under commissioning at Sincrotrone Trieste, Italy. In order to protect the facility's permanent undulator magnets from radiation-induced demagnetization,beam losses and radiation doses are monitored closely by an active machine protection system. The talk focuses on the design and performance of its main diagnostic subsystems: Beam loss position monitors based on the detection of Cherenkov light in quartz fibers with multi-pixel photon counters, conventional ionization chambers with a new frontend electronics package, and solid-state RadFET dosimeters providing an online measurement of the absorbed dose in the undulator magnets.  
slides icon Slides TUOA04 [2.559 MB]  
 
TUOB03 Next Generation Electronics based on μTCA for Beam-Diagnostics at FLASH and XFEL controls, feedback, laser, low-level-rf 294
 
  • P. Gessler, M.K. Bock, M. Bousonville, M. Felber, M. Hoffmann, T. Jezynski, T. Lamb, F. Ludwig, G. Petrosyan, L.M. Petrosyan, K. Rehlich, S. Schulz, P. Vetrov, M. Zimmer
    DESY, Hamburg, Germany
  • C. Bohm, A. Hidvégi
    Stockholm University, Stockholm, Sweden
  • K. Czuba
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  • D.R. Makowski
    TUL-DMCS, Łódź, Poland
  
  Funding: This work is partly supported by IRUVX-PP an EU co-funded project under FP7 (Grant Agreement 211285).
Almost all accelerator-related diagnostic and steering systems require front-end electronic hardware and software for digitizing, synchronization, processing, controlling, and providing access to the control system. Increasingly high demands on resolution, bandwidth, stability, redundancy, low latency, real-time processing and distribution create the need for new technologies in order to fulfill those demands. For this reason, at the European XFEL and FLASH, the new, μTCA industry standard will be deployed. Over the last few years, significant achievements have been made in μTCA developments in collaboration with other research institutes and industry. In this paper, we give an overview of the required components of a typical μTCA system for diagnostics applications. The FLASH bunch arrival-time monitor will be used as an example. 		 
slides icon Slides TUOB03 [9.075 MB]  
 
TUPD02 Beam Diagnostics for the ESS linac, target, cryomodule, proton 302
 
  • A. Jansson, L. Tchelidze
    ESS, Lund, Sweden
  
  The European Spallation Source (ESS) is a based on a 2.5GeV superconducting linac, producing a 5MW beam. Since it is optimized for cold neutrons, there is no accumulator ring, and hence no need for change exchange injection. Therefore, unlike most other proposed MW-class linacs, the ESS linac will accelerate protons rather than H− ions. This poses a particular challenge for beam size mesurements in the superconducting section. This paper discusses the ESS beam diagnostics requirements, along with some possible instrument design options.  
 
TUPD04 Diagnostics for the 150 MeV Linac and Test Transport Line of Taiwan Photon Source linac, emittance, site, electron 308
 
  • C.-Y. Liao, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo, D. Lee, K.-K. Lin, K.L. Tsai, C.Y. Wu
    NSRRC, Hsinchu, Taiwan
  
  The TPS 150 MeV linac is in installation and commissioning phase at the test site for acceptance test. The linac will move to the final installation site after the building complete which is expected in 2012. The linac and a short transport line for main parameters measurement equips with several types of diagnostic devices, which include screen monitors, fast current transformers, integrated current transformer, wall current monitors, beam position monitors and Faraday cups. These devices are arranged to measure the specification parameters such as charge in bunch train, pulse purity, energy, energy spread, and emittance. Implementation details and preliminary test results will be summarized in this report.  
 
TUPD05 Diagnostic Scheme for the HITRAP Decelerator ion, pick-up, rfq, dipole 311
 
  • G. Vorobjev, C.A. Andre, W.A. Barth, E. Berdermann, M.I. Ciobanu, G. Clemente, L.A. Dahl, P. Forck, P. Gerhard, R. Haseitl, F. Herfurth, M. Kaiser, W. Kaufmann, H.J. Kluge, N. Kotovski, C. Kozhuharov, M.T. Maier, W. Quint, A. Reiter, A. Sokolov, T. Stöhlker
    GSI, Darmstadt, Germany
  • O.K. Kester, J. Pfister, U. Ratzinger, A. Schempp
    IAP, Frankfurt am Main, Germany
  
  The HITRAP linear decelerator currently being set up at GSI will provide slow, few keV/u highly charged ions for atomic physics experiments. The expected beam intensity is up to 105 ions per shot. To optimize phase and amplitude of the RF systems intensity, bunch length and kinetic energy of the particles need to be monitored. The bunch length that we need to fit is about 2 ns, which is typically measured by capacitive pickups. However, they do not work for the low beam intensities that we face. We investigated the bunch length with a fast CVD diamond detector working in single particle counting mode. Averaging over 8 shots yields a clear, regular picture of the bunched beam. Energy measurements by capacitive pickups are limited by the presence of intense primary and partially decelerated beam and hence make tuning of the IH-structure impossible. The energy of the decelerated fraction of the beam behind the first deceleration cavity was determined to about 10 % accuracy with a permanent dipole magnet combined with a MCP. Better detector calibration should help reaching the required 1%. Design of the detectors as well as the results of the measurements will be presented.  
 
TUPD17 Spatial Resolution Test of a BPMS for DESIREE Beam Line Diagnostics ion, electron, rfq, simulation 338
 
  • S. Das, A. Källberg
    MSL, Stockholm, Sweden
  • J. Harasimowicz
    The University of Liverpool, Liverpool, United Kingdom
  
  Funding: Two of us (S.Das and J. Harasimowicz) acknowledge the financial support received from the European Commission within FP7 Marie Curie Initial Training Network DITANET
Spatial resolution of a beam profile monitoring system (BPMS) was tested. It will be a part of the DESIREE [1] diagnostics to monitor and cover the wide range of beam intensities and energies. The BPMS consists of an aluminum (Al) plate, a grid placed in front of Al, a microchannel plate (MCP), a fluorescent screen (F.S.), a PC, and a CCD camera [2]. A beam collimator containing a set of circular holes of different diameter and separation between them was built to check the spatial resolution of the system [3]. Two holes of diameter 1 mm, separated by 2 mm, in the collimator were used for this purpose. A proton beam was used for the measurements. It was observed that these holes create two beams of approximately same intensity of areas each of 1 mm in diameter with 2 mm separation between the beam centers on the screen, suggesting a resolution of 2 mm of the system. The resolution was tested for different beam energy (0.5-40 keV), and voltages applied on the Al and MCP plates. The experimental results will be compared with the simulations.
[1] www.msl.se;www.atom.physto.se/Cederquist/desiree_web_hc.html
[2] K. Kruglov et al, NIM A, 441, 595 (2002);Nucl. Phys. A, 701, 193c (2002)
[3] S. Das et al, Proceedíngs of DITANET workshop, Nov. 23-25, 2009 		 
 
TUPD23 New Bunch-by-Bunch Feedback System for the TLS feedback, controls, EPICS, kicker 353
 
  • C.H. Kuo, Y.K. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu
    NSRRC, Hsinchu, Taiwan
  
  FPGA based bunch-by-bunch feedback systems were deployed in 2005-2006 by using SPring-8 designed feedback processors for the Taiwan Light Source. To provide spare units and explore integrate with the control system in the EPICS toolkit environment, feedback processors from the Dimtel were setup. The new system can be swap with the existed system by simple cable re-connection and integrated with the EPICS system in seamless way. Rich functionality except the basic feedback function includes excitation of individual bunch or specifies bunches, averaged spectrum, tune measurement by the feedback dip in the averaged spectrum, fill pattern measurement, …etc. are explorer. Current stage implementation and features of the system will summary in this report.  
 
TUPD33 Coherent Resonant Diffraction Radiation from Inclined Grating as a Tool for Bunch Length Diagnostics radiation, electron, vacuum, synchrotron 377
 
  • L.G. Sukhikh, G. Kube
    DESY, Hamburg, Germany
  • A. Potylitsyn
    Tomsk Polytechnic University, Tomsk, Russia
  • V. Schlott
    PSI, Villigen, Switzerland
  
  There exists considerable interest in studying new types of non-invasive bunch length diagnostics for sub-picosecond bunches. In this context coherent Smith-Purcell radiation (CSPR) is a good candidate because the use of grating causes wavelength dispersive radiation emission, i.e. a CSPR based monitor does not require any additional spectrometer. In contrast to existing CSPR monitors a new scheme is proposed with two detectors placed at fixed positions, and a wavelength scan is performed by scanning the tilt angle between grating surface and beam axis. In this scheme the information of both detectors, positioned opposite to each other and perpendicular to the beam axis, can be combined by taking the intensity ratio of the signals from both detectors. The advantage of such diagnostics scheme is that one has not to rely on absolute values of the radiation yield, avoiding the need to know the sensitivity of each detector with high accuracy. In contrast to CSPR which is emitted from a grating oriented parallel to the beam, the effect is termed coherent resonant diffraction radiation when the grating is tilted. In the report we present simulation results and detailed experimental plan.  
 
TUPD38 Design of a Single-Shot Prism Spectrometer in the Near- and Mid-Infrared Wavelength Range for Ultra-Short Bunch Length Diagnostics electron, simulation, radiation, optics 386
 
  • C. Behrens
    DESY, Hamburg, Germany
  • A.S. Fisher, J.C. Frisch, A. Gilevich, H. Loos, J. Loos
    SLAC, Menlo Park, California, USA
  
  The successful operation of high-gain free-electron lasers (FEL) relies on the understanding, manipulation, and control of the parameters of the driving electron bunch. Present and future FEL facilities have the tendency to push the parameters for even shorter bunches with lengths below 10 fs and charges well below 100 pC. This is also the order of magnitude at laser-driven plasma-based electron accelerators. Devices to diagnose such ultra-short bunches even need longitudinal resolutions smaller than the bunch lengths, i.e. in the range of a few femtoseconds. This resolution is currently out of reach with time-domain diagnostics like RF-based deflectors, and approaches in the frequency-domain have to be considered to overcome this limitation. Our approach is to extract the information on the longitudinal bunch profile by means of infrared spectroscopy using a prism as dispersive element. In this paper, we present the design considerations on a broadband single-shot spectrometer in the near- and mid-infrared wavelength range (0.8 - 39.0 μm).  
 
TUPD40 Analysis of the Post-mortem Events at the TLS SRF, power-supply, dipole, injection 392
 
  • K.H. Hu, Y.-T. Chang, J. Chen, P.C. Chiu, K.T. Hsu, C.H. Kuo, Y.-H. Lin, Y.R. Pan
    NSRRC, Hsinchu, Taiwan
  
  Analyzing the reasons of various trip events are basis to improve reliability of a accelerator system. Understand the mechanisms caused trip of the machine will be very helpful to decide what the adequate measures to improve availability. To identify the causes of trips at Taiwan Light Source (TLS), various diagnostics tool were employed. These diagnostic tools can capture beam trips, interlock signals of superconducting RF system, quench and interlock signals of the superconducting insertion device, waveform of the injection kickers, and instability signals of the stored beam for post-mortem analysis. Various functionalities of trip diagnostic are supported. Available tools and experiences will be summarized in this report.  
 
TUPD41 The Beam Halo Monitor for FLASH electron, laser, free-electron-laser, radiation 395
 
  • A. Ignatenko, N. Baboi, O. Hensler, M. Schmitz, K. Wittenburg
    DESY, Hamburg, Germany
  • H.M. Henschel, W. Lange
    DESY Zeuthen, Zeuthen, Germany
  • A. Ignatenko, W. Lohmann
    BTU, Cottbus, Germany
  • S. Schuwalow
    University of Hamburg, Hamburg, Germany
  
  The Beam Halo Monitor (BHM) for FLASH based on pCVD diamond and monocrystalline sapphire sensors has been successfully commissioned and is in operation. It is a part of the beam dump diagnostics system that ensures safe beam dumping. The description of the BHM and experience gained during its operation are given in this paper.  
 
TUPD46 Beam Species Fraction Measurement using Doppler Shift Method with FUJIKURA Fiberscope for IFMIF-EVEDA Injector proton, target, neutron, radiation 407
 
  • F. Senée, B. Pottin
    CEA/DSM/IRFU, France
  • G. Adroit, R. Gobin, O. Tuske
    CEA/IRFU, Gif-sur-Yvette, France
  • A. Olivier
    IPN, Orsay, France
  
  To characterize high intensity ion beam in low energy beam transport line, diagnostics based on residual gas molecule excitation are commonly used. An example is CCD sensors for beam intensity, beam position and beam profile measurements. At CEA/Saclay with the SILHI injector, beam images transports from viewport to sensor have been performed with a fiberscope. Such technique will be used to transport the beam images away from the irradiated zone of the IFMIF-EVEDA tunnel which requires using hardened radiation devices. Indeed, the (D,d) reaction, due to interaction of 140 mA-100 keV deuteron beam with vacuum pipes or scrapers, leads to high neutron and gamma ray flux. As a consequence, in addition to CID cameras for online beam positioning and shape measurements, a 20 m long Fujikura fiberscope has been selected to analyze species fraction using the Doppler shift method. Preliminary measurements have been performed with the SILHI beam to characterize the fiberscope. Its spatial resolution and transmission as well as a CCD sensor and fiberscope comparison are presented. Beam species fractions with and without the use of fiberscope will be also reported.  
 
TUPD49 Performance of Parabolic and Diffusive OTR Screens at the CLIC Test Facility 3 dipole, linac, alignment, simulation 413
 
  • M. Olvegård, B. Bolzon, E. Bravin, S. Burger, A.E. Dabrowski, T. Lefèvre
    CERN, Geneva, Switzerland
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  At the CLIC Test Facility 3, OTR screens are commonly used in beam imaging systems for energy and energy spread characterization in dedicated spectrometer lines. In these lines the horizontal beam size is typically of the order of one centimeter. Already in 2005 a limitation was observed resulting from a strong dependence of the intensity of the light captured by the camera, on the position on the screen (vignetting). The severity of this effect increases with the electron energy, as the aperture of the optical system is finite and the OTR photons are emitted in a small cone of 1/γ angle. To mitigate this effect, different shapes and surface polishing of the screens were investigated. Parabolic and diffusive OTR radiators were tested in several spectrometer lines all along the CTF3 complex. The results are presented in this paper.  
 
TUPD53 A Low-Power Laser Wire with Fiber Optic Distribution laser, electron, scattering, pick-up 425
 
  • R.B. Wilcox, J.M. Byrd, M.S. Zolotorev
    LBNL, Berkeley, California, USA
  • V.E. Scarpine
    Fermilab, Batavia, USA
  
  Funding: This work was supported by the US Department of Energy under contract DE-AC02-05CH11231.
Laser-based position diagnostics for hydrogen ion (H−) beams typically use high power optical pulses that must be transported via free space to the diagnostic point. It is difficult to maintain stable alignment through such systems, especially when multiple channels are required. We describe a method for distributing low power, amplitude modulated pulse trains via fiber optic, and detecting interaction with the H− beam by synchronous detection of the stripped electrons. Trains of 10 ps, 1064 nm pulses at 400 MHz repetition rate are modulated by a 1 MHz signal that is the reference for a lockin amplifier. The average beam power is below one Watt. Synchronous detection at RF frequencies allows for efficient noise rejection when using optical powers below the nonlinear (Raman scattering) threshold of an optical fiber. The laser is synchronized with the bunch repetition rate, so the diagnostic can be used for bunch length measurements as well. We present results of tests of the optical system with 100 m, single-mode fiber and realistic detected signal levels, demonstrating detection of the modulation signal with high signal-to-noise ratio and low nonlinearity. 		 
 
TUPD58 Non-interceptive Profile Measurements using an Optical-based Tomography Technique laser, ion, vacuum, simulation 437
 
  • C.M. Mateo, G. Adroit, G. Ferrand, A. France, R. Gobin, S. Nyckees, Y. Sauce, F. Senée, O. Tuske
    CEA/IRFU, Gif-sur-Yvette, France
  
  Funding: This work is supported by the DITANET Marie Curie European network
Most of the charged particle beam shapes do not possess symmetry. In such cases, diagnostic measurement obtained in one direction is not enough to reconstruct the spatial distribution of the beam. The use of intense beams which demands for non-interceptive diagnostic devices posed another challenge in measuring the beam’s spatial distribution. At CEA Saclay and within the DITANET framework, the use of tomography combined with optical diagnostics to develop a non-interceptive transverse profile monitor is under development. This profile monitor is presently tested on the BETSI test bench. In this contribution, a tomography algorithm suited for beam profile measurements is presented. This algorithm is based on the formulation of iterative Algebraic Reconstruction Technique (ART) problem and the Maximum-Likelihood Expectation Maximization (MLEM) for the iteration step. The algorithm is optimized within the limit of using 6 projections only. Several beam shapes are generated and then reconstructed computationally. Actual measurements in the BETSI test bench are also done to verify the tomographic reconstruction process. 		 
 
TUPD60 Optical Diagnostics for Frankfurt Neutron Source emittance, simulation, factory, neutron 443
 
  • H. Reichau, O. Meusel, U. Ratzinger, C. Wagner
    IAP, Frankfurt am Main, Germany
  
  A non-interceptive optical diagnostic system on the basis of beam tomography, was developed for the planned Frankfurt Neutron Source (FRANZ). The proton driver linac of FRANZ will provide energies up to 2.0 MeV. The measurement device will non-interceptively derive required beam parameters at the end of the LEBT at beam energies of 120 keV and a current of 200 mA. On a narrow space of 351.2 mm length a rotatable tomography tank will perform a multi-turn tomography with a high and stable vacuum pressure. The tank allows to plug different measurement equipment additionally to the CCD Camera installed, to perform optical beam tomography. A collection of developed algorithms provides information about the density distribution, shape, size, location and emittance on the basis of CCD images. Simulated, as well as measured data have been applied to the evaluation algorithms to test the reliability of the beam. The actual contribution gives an overview on the current diagnostic possibilities of this diagnostic system.  
poster icon Poster TUPD60 [1.886 MB]  
 
TUPD67 Injection Efficiency Diagnostic at TLS Storage Ring injection, storage-ring, booster, septum 461
 
  • P.C. Chiu, J. Chen, Y.K. Chen, K.T. Hsu, K.H. Hu, C.H. Kuo
    NSRRC, Hsinchu, Taiwan
  
  TLS is now running at 360 mA top-up mode. In the normal situation, it takes few minutes for injection from zero current to 360 mA. When the working point is drifted too much at machine start, however, injection efficiency become worsen and it is necessary to adjust some machine parameters such as quadrupole strength, transport line correctors or booster dipole to improve efficiency. The current reading at 10 Hz time resolution which is the same with injection cycle seems too rough to estimate efficiency therefore a new diagnostic tool based on BPM sum reading is developed to provide 10 kHz waveform display every second. Operators could utilize it to estimate efficiency more precise, quickly and easier.  
poster icon Poster TUPD67 [0.842 MB]  
 
TUPD69 Operational Experience and Improvements of the LHC Beam Current Transformers vacuum, feedback, luminosity, proton 467
 
  • P. Odier, D. Belohrad, J-J. Gras, M. Ludwig
    CERN, Geneva, Switzerland
  
  During the 2010 run the LHC continuously improved its performance. In particular the bunch charge and number of bunches were significantly increased, which revealed certain limitations of the LHC beam current transformers. The DC current transformers (DCCT), used to measure the circulating beam current, exhibited saturation related to bunch intensity, the number of batches in the machine and their spacing. Two major issues were also discovered on the fast beam current transformers (FBCT) used to measure the individual bunch charges: discrepancies in the measured intensities when compared to the DCCTs measurements and a bunch length dependence on the measured intensity. Further analysis showed that both problems are linked to the beam position dependence of the signal acquired from the toroids used in the FBCTs. This paper presents the observed issues, discusses possible solutions and reports on the results from modification made for the 2011 run.  
 
TUPD72 Advancements in the Base-Band-Tune and Chromaticity Instrumentation and Diagnostics Systems during LHC's First Year of Operation feedback, synchrotron, resonance, monitoring 476
 
  • R.J. Steinhagen, M. Gasior, S. Jackson
    CERN, Geneva, Switzerland
  
  The Base-Band-Tune (BBQ) system is an integral part of day-to-day LHC operation, used for tune and chromaticity diagnostics and feedback and giving unprecedented precision with good reliability. This contribution summarises the system's overall performance and documents the various improvements of the analogue front-end circuitry, digital post-processing and integration that were necessary in response to issues arising during high-intensity physics operation. The result of beam studies undertaken are presented, which have established a better understanding of the detection principle since its first introduction in 2005.  
poster icon Poster TUPD72 [0.794 MB]  
 
TUPD76 Vibration and Beam Motion Diagnostics in TLS electron, photon, status, monitoring 485
 
  • Y.K. Chen, J. Chen, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo
    NSRRC, Hsinchu, Taiwan
  
  High beam stability is essential in a modern synchrotron light source due to small emittance. Beam motion caused by various factors should be remedy by various approaches to achieve high beam stability. Vibration will deteriorate beam stability and need considered as a part of beam diagnostic. An integrated environment for beam orbit and vibration monitoring systems were set up for various studies. Implementation details and some beam observation will be presented in this report.  
poster icon Poster TUPD76 [2.750 MB]  
 
TUPD88 A Micro-Channel Plate Based RFA Electron Cloud Monitor for the ISIS Proton Synchrotron electron, gun, proton, synchrotron 512
 
  • A. Pertica, S.J. Payne
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  Electron clouds produced inside a particle accelerator vacuum chamber by the passage of the beam can compromise the operation of the accelerator. The build up of electron clouds can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the phenomena of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which provides energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. In this paper, we describe the lab based experiment used to test our detector using a low energy electron gun. Results from our MCP based detector installed in the ISIS accelerator ring are discussed and compared to a RFA detector, installed at the same location, which has no MCP fitted.  
poster icon Poster TUPD88 [1.793 MB]  
 
TUPD91 Comparative Studies of Reconstruction Methods to Achieve Multi-Dimensional Phase Space Information emittance, proton, ion, FEL 521
 
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • D. Reggiani, M. Seidel
    PSI, Villigen, Switzerland
  
  High Intensity Proton Accelerators like SNS, PSI or future machines like ESS or Isis upgrade cannot tolerate high losses due to activation. Standard beam diagnostics may not provide enough information about potential loss sources like beam filamentation or halo. Moreover, the application of interceptive methods like slits or pepperpot can be seriously discouraged by either high power deposition or explicit requirements for non-destructive methods like on-line diagnostics near superconducting cavities. Reconstruction of the beam distribution with a tomography method based on Maximum Entropy could help to overcome those problems and is easily to integrate in already existing facilities because the algorithm does not depend on the experimental profile measurement technique. Furthermore beam tomography can be employed on both spatial and phase-space reconstruction. The paper compares results from two different software packages from PSI (Maximum Entropy Tomography MENT) with the code used at RAL (MemSys 5).  
 
TUPD97 Diagnostic System of TAC IR FEL Facility electron, FEL, emittance, linac 536
 
  • Z. Nergiz
    N.U, Nigde, Turkey
  • A. Aksoy
    Ankara University, Faculty of Engineering, Tandogan, Ankara, Turkey
  • S. Ceylan, S. Özkorucuklu
    SDU, Isparta, Turkey
  • C. Kaya
    HZDR, Dresden, Germany
  
  The TAC (Turkish Accelerator Center) IR FEL facility which is named as Turkish Accelerator and Radiation Laboratory at Ankara, TARLA will be based on a 15-40 MeV electron linac accompanying two different undulators with 2.5 cm and 9 cm periods in order to obtain IR FEL ranging between 2-250 microns. The electron linac will consist of two sequenced modules, each housing two 9-cell superconducting TESLA cavities for cw operation. It is planned that the TARLA facility will be completed in 2013 at Golbasi campus of Ankara University. This facility will give an opportunity to the scientists and industry to use FEL in research and development in Turkey and our region. In this study, the main structure of the facility and planned electron beam diagnostics system is given in detail.  
poster icon Poster TUPD97 [0.514 MB]  
 
WEOA01 Summary of COTR Effects radiation, FEL, emittance, electron 539
 
  • S. Wesch, B. Schmidt
    DESY, Hamburg, Germany
  
  Coherent transition radiation in the visible regime (COTR) has become a serious issue in FEL - Linacs disturbing the measurement of beam profiles by OTR screens up to a level, where this diagnostics becomes totally impossible. The talk will summarize the measured COTR effects from LCLS, FLASH and other machines and the investigations done so far into the dependence of the effect on beam and machine parameters. The status of the theoretical background and understanding of its origin will be discussed as well as proposals and experiences with possible remedies.  
slides icon Slides WEOA01 [2.520 MB]  
 
WEOA02 Experimental Investigations of Backward Transition Radiation from Flat Target in Extreme Ultraviolet Region radiation, target, electron, FEL 544
 
  • L.G. Sukhikh, G. Kube
    DESY, Hamburg, Germany
  • D. Krambrich, W. Lauth
    IKP, Mainz, Germany
  • Yu.A. Popov, A. Potylitsyn
    Tomsk Polytechnic University, Tomsk, Russia
  
  Forward transition radiation in X-ray range and backward transition radiation (BTR) in optical spectral region are investigated in details due to their use for purposes of particle and beam diagnostics. In order to improve diagnostics tools we proposed to use BTR in extreme ultraviolet (EUV) region [*,**], where theoretical models are existing only. We performed experimental investigations of BTR characteristics in EUV spectral region generated by a molybdenum target at 855 MeV electron beam of the MAMI-B (Mainz, Germany). Angular patterns and intensities of BTR both in optical and EUV regions for different observation angles were investigated. The measured intensity of optical BTR agrees with a theory with reasonable accuracy but one in EUV region is more intense than theoretically predicted. Our experimental estimation of the experimental BTR yield in EUV region is (2.4/3.6)•10−4 photons/electron and this is more than 4 / 6 times higher than the theoretical value.
* L.G. Sukhikh, S.Yu.Gogolev and A.P.Potylitsyn, Nucl. Instrum. Methods Phys. Res., Sect. A 623, 567 (2010)
** L.G. Sukhikh, S.Yu.Gogolev and A.P.Potylitsyn, J. Phys.: Conf. Ser. 236, 012011 (2010). 		 
slides icon Slides WEOA02 [6.967 MB]  
 
WEOB01 Scintillating Screen Applications in Beam Diagnostics electron, ion, photon, scattering 553
 
  • B. Walasek-Höhne
    GSI, Darmstadt, Germany
  • G. Kube
    DESY, Hamburg, Germany
  
  Scintillation screens are widely used for transverse beam profile diagnostics at particle accelerators. The monitor principle relies on the fact that a charged particle crossing the screen material will deposit a part of its energy which is converted to visible light. The resulting light spot is a direct image of the two-dimensional beam distribution and can be measured with standard optical techniques. Scintillating screen monitors were mainly deployed in hadron and low energy electron machines where the intensity of optical transition radiation (OTR) is rather low. The experience from modern linac based light sources showed that OTR diagnostics might fail even for high energetic electron beams, thus making the use of scintillators again very attractive. This contribution summarizes results and trends from "Scintillating Screen Applications in Beam Diagnostics" workshop recently held in Darmstadt. In the first part an introduction to the scintillation mechanism will be given, including demands and limitations as e.g. the dynamic range and saturation. Thereafter a brief overview on actual screen monitor applications at electron and hadron accelerators will be presented.  
slides icon Slides WEOB01 [14.721 MB]  
 
WEOB02 Experimental Comparison of Performance of Various Fluorescent Screens Applied for Relativistic Electron/Positron Beam Imaging electron, positron, booster, laser 558
 
  • O.I. Meshkov, V.A. Kiselev, D.P. Sukhanov, A.N. Zhuravlev
    BINP SB RAS, Novosibirsk, Russia
  • V.L. Dorokhov, V.V. Smaluk
    BINP, Novosibirsk, Russia
  • E.N. Galashov
    Nikolayev Institute of Inorganic Chemistry, Novosibirsk, Russia
  
  Fluorescent screens are widely used for single-pass measurements of transverse beam profile at most of accelerator facilities. Great number of materials is now used for manufacture of fluorescent screens. The linearity, sensitivity and spatial resolution of the diagnostics depend on the choice of screen substance. We made an attempt to compare a linearity and relative light yield for few types of the fluorescent materials applied for screen manufacturing. A CCD-camera and photomultiplier tube record the light flux and 2D profile of the electron/positron beam image on the screen. Experiments were carried out with the electron/positron beam energy of 350 MeV and the beam charge of 0.1 – 100 pC.  
slides icon Slides WEOB02 [3.454 MB]  
 
WEOD01 Beam Induced Fluorescence Monitors ion, photon, electron, proton 575
 
  • F. Becker
    GSI, Darmstadt, Germany
  
  Non-intercepting diagnostic devices in hadron accelerators offer continuous online monitoring capability. They also avoid the problem of potential thermal damage in high-current applications. Taking advantage of the residual gas as active material, the Beam Induced Fluorescence (BIF) monitor exploits gas fluorescence in the visible range for transversal profile measurements. Depending on beam parameters and vacuum-constraints, BIF monitors can be operated at base-pressure or in dedicated local pressure bumps up to the mbar range. Nowadays, BIF monitors are investigated in many accelerator laboratories for hadron energies from about 100 keV up to several 100 GeV. This talk gives an introduction to the measurement principle and typical operating conditions. It summarises recent investigations, e.g. on different working gases, and it compares various technical realisations.  
slides icon Slides WEOD01 [12.701 MB]