Keyword: radiation
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MOBL1 Instrumentation and Results from the SwissFEL Injector Test Facility diagnostics, transverse, electron, laser 12
 
  • R. Ischebeck, V.R. Arsov, S. Bettoni, B. Beutner, M.M. Dehler, A. Falone, F. Frei, I. Gorgisyan, Ye. Ivanisenko, P.N. Juranic, B. Keil, F. Löhl, G.L. Orlandi, M. Pedrozzi, P. Pollet, E. Prat, T. Schietinger, V. Schlott, B. Smit
    PSI, Villigen PSI, Switzerland
  • P. Peier
    DESY, Hamburg, Germany
  
  The SwissFEL Injector Test Facility (SITF) has been equipped with numerous prototype diagnostics (BPMs, screen monitors, wire scanners, optical synchrotron radiation monitor, compression (THz) monitor, bunch arrival time monitor, EO spectral decoding monitor, charge and loss monitor) specifically designed for the low charge SwissFEL operation modes. The design of the diagnostics systems and recent measurement results will be presented.  
slides icon Slides MOBL1 [35.165 MB]  
 
MOCL2 Design of a Novel Cherenkov Detector System for Machine Induced Background Monitoring in the CMS Cavern background, LHC, simulation, shielding 33
 
  • S. Orfanelli, A.E. Dabrowski, M. Giunta
    CERN, Geneva, Switzerland
  • M.J. Ambrose, A. Finkel, R. Rusack
    University of Minnesota, Minneapolis, Minnesota, USA
  • D.P. Stickland
    PU, Princeton, New Jersey, USA
  
  A novel detector system has been designed for an efficient online measurement of the machine induced background in the CMS experimental cavern. The suppression of the CMS cavern background originating from pp collision products and the 25 ns bunch spacing have set the requirements for the detector design. Each detector unit will be a radiation hard, cylindrical Cherenkov radiator optically coupled to an ultra-fast UV-sensitive photomultiplier tube, providing a prompt, directionally sensitive measurement. Simulation and test beam measurements have shown the achievability of the goals that have driven the baseline design. The system will consist of 20 azimuthally distributed detectors per end, installed at a radius of r ~ 180 cm and a distance 20.6 m away from the CMS interaction region. The detector units will enable a measurement of the transverse distribution of the bunch-by-bunch machine induced background flux. This will provide important feedback from the CMS on the beam conditions during the LHC machine setup and comparisons to expectations based on FLUKA simulations.  
slides icon Slides MOCL2 [14.094 MB]  
 
MOPC10 Optimization of NSLS-II Blade X-ray Beam Position Monitors: From Photoemission Type to Diamond Detector undulator, DIAMOND, photon, beam-position 67
 
  • P. Ilinski
    BNL, Upton, Long Island, New York, USA
  
  Optimization of blade type X-ray Beam Position Monitors (XBPM) was performed for NSLS-II undulator IVU20. Blade material, configuration and operation principle were analyzed. Optimization is based on calculation of the XBPM signal spatial distribution. Along with standard photo-emission blades, Diamond Detector Blade (DDB) was examined as XBPM signal source. Analyses revealed, that Diamond Detector Blade XBPM would allow to overcome drawbacks of the photo-emission type XBPMs.  
 
MOPC34 Longitudinal Beam Profile Monitor for Investigating the Microbunching Instability at Diamond Light Source optics, DIAMOND, longitudinal, storage-ring 143
 
  • W. Shields, R. Bartolini, A.F.D. Morgan, G. Rehm
    Diamond, Oxfordshire, United Kingdom
  • R. Bartolini, P. Karataev
    JAI, Oxford, United Kingdom
  • P. Karataev
    Royal Holloway, University of London, Surrey, United Kingdom
  
  An investigation into the microbunching instability at Diamond Light Source has recently been conducted. Beyond the instability threshold, the bunch emits bursts of coherent synchrotron radiation with wavelengths comparable to the bunch length or shorter. The operating conditions for producing the instability include both normal optics, and low-alpha optics, where the bunch length can be shortened to a few picoseconds. A Michelson interferometer has been designed and installed utilising a silicon crystal wafer beamsplitter. Large bandwidth, room temperature pyroelectric detectors and low-noise, fast-response Schottky Barrier diode detectors have been employed to generate interferograms. In this paper, we describe the observed spectral content and the resulting calculated bunch length.  
 
MOPC37 Longitudinal Bunch Profile Reconstruction Using Broadband Coherent Radiation at FLASH longitudinal, electron, transverse, laser 154
 
  • E. Hass
    Uni HH, Hamburg, Germany
  • C. Behrens, C. Gerth, B. Schmidt, M. Yan
    DESY, Hamburg, Germany
  • S. Wesch
    HZB, Berlin, Germany
  
  The required high peak current in free-electron lasers is realized by longitudinal compression of the electron bunches to sub-picosecond length. Measurement of the absolute spectral intensity of coherent radiation emitted by an electron bunch allows monitoring and reconstruction of the longitudinal bunch profile. To measure coherent radiation in the teraherz and infrared range a in-vacuum coherent radiation intensity spectrometer was developed for the free-electron laser in Hamburg(FLASH). The spectrometer is equipped with five consecutive dispersion gratings and 120 parallel readout channels: it can be operated either in short (5-44 um) or in long wavelength mode (45-430 um). Fast parallel readout permits the monitoring of coherent radiation from single electron bunches. Large wavelength coverage and superb absolute calibration of the device allows reconstruction of the longitudinal bunch profile using Kramers-Kronig based phase retrieval technique. The device is used as a bunch length monitor and tuning tool during routine operation at FLASH. Comparative measurements with radio-frequency transverse deflecting structure show excellent agreement of both methods.  
 
MOPC46 Beam Loss Monitor System for Low-Energy Heavy-Ion FRIB Accelerators ion, beam-losses, background, heavy-ion 186
 
  • Z. Liu, T. Russo, R.C. Webber, Y. Yamazaki, Y. Zhang
    FRIB, East Lansing, Michigan, USA
  
  Funding: Work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Radiation transport simulations reveal shortcomings in the use of ion chambers for the detection of beam losses in low-energy, heavy-ion accelerators like FRIB. Radiation cross-talk effects due to the specific FRIB paper-clip geometry complicate locating specific points of beam loss. We describe an economical and robust solution that complements ionization chambers. A specifically designed device, the halo monitor ring (HMR), is implemented upstream of each cryomodule to detect beam loss directly. Together with fast response neutron scintillators, the new integrated BLM system satisfies both machine protection and sensitivity requirements. 		 
poster icon Poster MOPC46 [1.014 MB]  
 
MOPF01 Transverse Beam Size Measurements Using Interferometry at ALBA vacuum, transverse, synchrotron, dipole 193
 
  • U. Iriso, L. Torino
    CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
  • T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  
  Double-slit interferometry using visible light has been used for measuring the transverse beam size in different accelerators. The beam size is inferred from the analysis of the spatial coherence of the synchrotron light produced by a bending magnet. At ALBA, this technique has been implemented with moderate success, mainly limited by the present imperfections in the in-vacuum mirror that is used to extract the light out of the vacuum chamber. In this paper, we report the results obtained with the current set-up, and discuss possible improvements.  
 
MOPF03 Laser Diode Velocimeter-Monitor Based on Self-Mixing Technique target, laser, feedback, scattering 200
 
  • A.S. Alexandrova, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A.S. Alexandrova, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  Funding: Work supported within LA3NET which is funded by the European Commission under contract PITN-GA-2011-289191 and STFC under the Cockcroft Institute Core Grant No.ST/G008248/1.
Gas targets are important for a number of accelerator-based applications, in particular as cold targets for collision experiments and beam diagnostics purposes where gas jets have been successfully used as least intrusive beam profile monitors, however, detailed information about the gas jet is important for its optimization and the quality of the beam profile that can be measured with it. A laser velocimeter shall be used for an in-detail characterization of atomic and molecular gas jets and allow investigations into the jet dynamics. Existing methods are currently not efficient enough, hard to build, and rather expensive. A laser velocimeter based on the self-mixing technique can provide unambiguous measurements from a single interferometric channel, realizable in a compact experimental setup that can be installed even in radiation-exposed environments. In this contribution, an introduction to the underlying theory of self-mixing is given, before the design and functioning principle of the velocimeter is described in detail. Finally, preliminary experimental results with different solid targets are presented and an outlook on measurements with fluid and gaseous targets is given. 		 
poster icon Poster MOPF03 [1.045 MB]  
 
MOPF04 Results of the High Resolution OTR Measurements at KEK and Comparison with Simulations simulation, OTR, KEK, target 204
 
  • B. Bolzon, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A.S. Aryshev
    KEK, Ibaraki, Japan
  • B. Bolzon, T. Lefèvre, S. Mazzoni
    CERN, Geneva, Switzerland
  • B. Bolzon, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • P. Karataev, K.O. Kruchinin
    Royal Holloway, University of London, Surrey, United Kingdom
  • P. Karataev
    JAI, Egham, Surrey, United Kingdom
  
  Optical Transition Radiation (OTR) is emitted when a charged particle crosses the interface between two media with different dielectric properties. It has become a standard tool for beam imaging and transverse beam size measurements. At the KEK Accelerator Test Facility 2 (ATF2), OTR is used at the beginning of the final focus system to measure a micrometre beam size using the decrease in visibility of the OTR Point Spread Function (PSF). In order to study and improve the resolution of the optical system, a novel simulation tool has been developed in order to characterize the PSF in detail. Based on the physical optic propagation mode of ZEMAX, the propagation of the OTR electric field can be simulated very precisely up to the image plane, taking into account aberrations and diffraction coming through the designed optical system. This contribution will show the results of measurements performed after a first improvement of the ATF2 OTR optical design to confirm the very high resolution of the imaging system and the performance of this simulation tool.  
poster icon Poster MOPF04 [1.590 MB]  
 
MOPF10 Off-Axis Undulator Radiation for CLIC Drive Beam Diagnostics undulator, CLIC, electron, transverse 228
 
  • A. Jeff, T. Lefèvre
    CERN, Geneva, Switzerland
  • A. Jeff, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A. Jeff, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 1015 electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. In this paper we propose the use of relatively inexpensive permanent-magnet undulators to generate off-axis visible Synchrotron Radiation from the CLIC Drive Beam. The field strength and period length of the undulator should be designed such that the on-axis undulator wavelength is in the ultra-violet. A smaller but still useable amount of visible light is then generated in a hollow cone. This light can be reflected out of the beam pipe by a ring-shaped mirror placed downstream and imaged on a camera. In this contribution, results of SRW and ZEMAX simulations using the CLIC Drive Beam parameters are shown.  
 
MOPF14 Scintillation Screen Response to Heavy Ion Impact ion, GSI, UNILAC, transverse 235
 
  • E. Gütlich, O.K. Kester
    IAP, Frankfurt am Main, Germany
  • P. Forck, O.K. Kester
    GSI, Darmstadt, Germany
  
  For quantitative transverse ion beam profile measurement, imaging properties of scintillation screens have been investigated for the working conditions of the GSI linear accelerator. In the ion energy range between 4.8 and 11.4 MeV/u the imaging properties of the screens are compared with profiles obtained using standard techniques like SEM grids and scraper. Detailed investigations with e.g. Calcium and Argon ion beams on various radiation-hard materials show that the measured beam profiles can differ from those measured with standard methods and depend on several beam and material parameters *. For the practical usage of scintillators, it is necessary to have predictions for the response of the scintillator to a given ion beam. An existing model for the light output of scintillators for single particle irradiation has been extended to include the effect of overlapping excitation tracks. To validate the model, dedicated measurements with well-defined Carbon and Titanium ion beams at 11.4 MeV/u have been carried out. To understand the mechanisms, the beam flux and the pulse length has been varied. The measured light yield is compared to the model calculations.
* E. Gütlich et al., “Scintillation screen studies for high dose ion beam applications”, IEEE Transactions on Nuclear Science, Vol. 59, No. 5, October 2012, pp. 2354 – 2359. 		 
poster icon Poster MOPF14 [0.818 MB]  
 
MOPF20 Bunch Purity Measurement for BEPCII synchrotron, photon, synchrotron-radiation, electron 252
 
  • H. Jun, J.S. Cao, J.H. Junhui
    IHEP, Beijing, People's Republic of China
  
  The bunch purity is very important for time-resolved experiments. It is determined by the quality of the injection system and Touschek effect. The Beijing Electron-Positron Collider (BEPC) II was constructed for both high energy physics (HEP) and synchrotron radiation (SR) researches. It can be operated in the colliding mode and synchrotron radiation mode. It is planned to measure the beam quality in a short time of several minutes by using a timecorrelated single photon counting method. The method has a time resolution of 450 ps and a dynamic range of five orders of magnitude. In this paper, we describe our experimental set up and give a series of test results for colliding mode. We plan to set up a system which can kick out the unwanted bunches in the next stage.  
 
MOPF27 A Beam Current Monitor for the VECC Accelerator linac, gun, diagnostics, vacuum 275
 
  • W.R. Rawnsley, R.E. Laxdal
    TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
  
  TRIUMF is building VECC, the first stage of a 50 MeV electron linac. Beam diagnostic devices will be inserted radially into 8-port vacuum boxes. RF shields, 6.3 cm dia. tubes perforated by pump out slots, can be inserted to reduce wakefields. They will also serve as capacitive probes picking up harmonics of the 650 MHz bunch rate. 100 mV P/P was measured for 3 mA at 100 kV. A SC cavity will accelerate the beam to 10 MeV. The dump current is limited by the shielding to 300 W. We will use a 3 mA beam at 1% duty cycle. Two RF shields will monitor the current. A newly developed circuit will give dc outputs proportional to the peak and average current. It uses a log detector with range of 70 dB for 1 dB of error and a rise and fall time of ~20 ns. Terasic development boards process the log signal. It is digitized by a 14-bit ADC at a 50 MHz rate and passed to a FPGA programmed in Verilog. Altera Megafunctions offset, scale, convert to floating point, antilog and filter the signal in a pipeline architecture. Two 14-bit DACs provide the outputs. Digital processing maintains the wide dynamic range. Beam pulses can be <250 ns and the sample rate insures accuracy at low duty cycle.  
poster icon Poster MOPF27 [1.314 MB]  
 
TUAL3 Absolute Bunch Length Measurements at Fermi@ELETTRA FEL electron, ELETTRA, background, instrumentation 312
 
  • R. Appio
    MAX-lab, Lund, Sweden
  • P. Craievich, G. Penco, M. Veronese
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • P. Craievich
    PSI, Villigen PSI, Switzerland
  
  Electron bunch length measurements are of crucial importance for many types of accelerators, including storage rings, energy recovery linacs, free electron lasers. Many devices and instrumentation have been developed to measure and control the electron bunch length. A very powerful class of diagnostic tools is based on the coherent radiation power emitted by the electron bunch, that allows a non-destructive shot by shot measurement, well suitable for bunch length control feedback implementation. However they usually provide measurements of the bunch length relative variation, and external instrumentation like a transverse RF deflecting cavity is usually needed to calibrate them and to obtain absolute bunch length estimations. In this paper we present a novel experimental methodology to self-calibrate a device based on diffraction radiation from a ceramic gap. We indeed demonstrate the possibility to use coherent radiation based diagnostic to provide absolute measurements of the electron bunch length. We present the theoretical basis of the proposed approach and validate it through a detailed campaign of measurements that have been carried on in the FERMI@Elettra FEL linac.  
slides icon Slides TUAL3 [1.126 MB]  
 
TUCL1 Overview of Imaging Sensors and Systems Used in Beam Instrumentation optics, electron, controls, instrumentation 331
 
  • E. Bravin
    CERN, Geneva, Switzerland
  
  The presentation will give an overview of applicable image sensors and sensor systems for an application in the beam instrumentation. The overview will cover fast imaging cameras as well as sensors and cameras to be used in radiation fields. The critical parameters will be discussed and measurements presented if available. Frame grabbers and digital cameras will also be included in the presentation.  
slides icon Slides TUCL1 [8.924 MB]  
 
TUPC37 Presentation of the Smith-Purcell Experiment at SOLEIL SOLEIL, linac, vacuum, longitudinal 460
 
  • N. Delerue, J. Barros, S. Jenzer, M. Vieille Grosjean
    LAL, Orsay, France
  • L. Cassinari, M. Labat
    SOLEIL, Gif-sur-Yvette, France
  • G. Doucas, I.V. Konoplev, A. Reichold
    JAI, Oxford, United Kingdom
  • A. Faus-Golfe, N. Fuster Martinez, J. Resta-López
    IFIC, Valencia, Spain
  
  Funding: Work supported by seed funding from Université Paris-Sud, program 'Attractivité' and by the French ANR under contract ANR-12-JS05-0003-01.
The potential of Coherent Smith-Purcell radiation as a longitudinal bunch profile monitor has already been demonstrated and has recently been extended to the sub-picosecond range. As a critical step toward the construction of a single shot bunch profile monitor using Coherent Smith-Purcell radiation it is important to measure very accurately the distribution of such radiation. Optimum background suppression techniques need to be found and relatively cheap detectors suitable for the far infra-red need to be qualified. To perform these tasks a test stand has been installed at the end of the linac of the synchrotron SOLEIL. This test stand and the first results from its commissioning will be presented here. 		 
 
TUPC38 Longitudinal Profile Monitor Using Smith-Purcell Radiation: Recent Results from the E-203 Collaboration longitudinal, electron, SLAC, background 464
 
  • N. Delerue, J. Barros, S. Le Corre, M. Vieille Grosjean
    LAL, Orsay, France
  • H.L. Andrews
    LANL, Los Alamos, New Mexico, USA
  • F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, C. Perry, A. Reichold, S. Stevenson
    JAI, Oxford, United Kingdom
  • V. Bharadwaj, C.I. Clarke
    SLAC, Menlo Park, California, USA
  • N. Fuster Martinez
    IFIC, Valencia, Spain
  • M. Labat
    SOLEIL, Gif-sur-Yvette, France
  
  Funding: Financial support from the John Adams Institute, the Fell Fund (University of Oxford), the Université Paris-Sud (programme 'Attractivité') and the French ANR (contract ANR-12-JS05-0003-01).
We report on recent measurements made at FACET by the E-203 collaboration to test a longitudinal bunch profile monitor based on Coherent Smith-Purcell radiation. The capacity of this monitor to resolve sub-picosecond bunches will be shown as well as a comparison of profile reconstructed for different beam compression settings. We will also present recent electromagnetic simulations of the interactions between the beam and the grating as well as the expected resolution of such monitor. Comparison between Coherent Smith-Purcell radiation measurement and those made with other techniques will also be discussed. Finally future upgrades of the experiment and steps toward the construction of a single shot longitudinal profile monitor will be presented. 		 
 
TUPC39 Dispersive Fourier-Transform Electrooptical Sampling for Single-Shot Modulation Measurement in a Proton-Driven Plasma Wakefield Accelerator proton, plasma, laser, transverse 467
 
  • O. Reimann
    MPI-P, München, Germany
  • R. Tarkeshian
    MPI, Muenchen, Germany
  
  The concept of proton-driven plasma wakefield acceleration has recently been proposed as a means of accelerating a bunch of electrons to high energies with very high gradients, and a demonstration experiment (AWAKE) at CERN is now under development. For this a clear understanding of the temporal and spatial modulation of the proton driver bunches after propagating the plasma channel is essential. A single-shot electrooptical sampling system using dispersive Fourier-transform exploiting transverse coherent transition radiation* is proposed here to determine the bunch modulation and field properties in the frequency domain. Frequencies up to the terahertz region with a resolution of less than 10 GHz are measurable. The system with a closed optical fiber path is based on a semiconductor laser source to achieve easy handling and robustness. The principle idea, estimations of the required sensitivity, and first experimental results are presented.
* Pukhov, A. et al. Phys. Rev.ST Accel. Beams 15 (2012) 		 
 
TUPC40 Bunch Length Measurements Using Correlation Theory in Incoherent Optical Transition Radiation OTR, electron, longitudinal, laser 471
 
  • B. Smit, F. Frei, R. Ischebeck, G.L. Orlandi, V. Schlott
    PSI, Villigen PSI, Switzerland
  
  Funding: Paul Scherrer Institut (PSI)
As Free Electron Lasers create ultra-short bunch lengths, the longitudinal diagnostic for such femto-second bunches becomes more difficult. We suggest a bunch length method using the spectral analysis of incoherent Optical Transition Radiation (OTR) in the visible frequency domain. The frequency response of OTR is taken by inserting an aluminium coated silicon wafer into the electron beam. The OTR light is collected with mirror optics into an optical fibre, which is coupled to a spectrometer (334 THz to 1500 THz). The resolution of the spectrometer allows us to measure bunch length lower than 100 fs rms. Bunch length was varied from 100 femto-seconds down to a few femto-seconds. The spectral response of Optical Transition Radiation (OTR) showed an increase of the correlation between neighbouring frequencies as bunch length was reduced. 		 
 
TUPC45 DOSFET-L02: An Advanced Online Dosimetry System for RADFET Sensors monitoring, ELETTRA, controls, undulator 481
 
  • L. Fröhlich, S. Grulja
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • F. Löhl
    PSI, Villigen PSI, Switzerland
  
  Funding: This work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3.
Radiation-sensing field-effect transistors (RADFETs) are integrating dosimeters that have found wide application in space and particle accelerator environments. We present a new system, the DOSFET-L02, for the readout of up to four RADFET sensors. The system features enhanced readout stability, support for long sensor cables, an adjustable exposure bias voltage of up to 30 V, and integrated temperature measurement. Recent measurements demonstrate the performance of the system with RADFETs at bias voltages of 9 V, 25 V, and under zero bias. 		 
 
TUPC47 Simulation for Radiation Field Caused by Beam Loss of C-ADS Injector II proton, photon, beam-losses, electron 489
 
  • G. Ren, W. Li, Y. Li
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  • M. Zeng
    Tsinghua University, Beijing, People's Republic of China
  
  CADS is a Chinese ADS(Accelerator Driven Sub-critical System) project. Its injector is a high current, full superconducting proton accelerator. For such a facility, a BLM system is necessary, especially in low energy segments. This paper presents some basic simulation for 10MeV proton by Monte Carlo program FLUKA, as well as the distributions we got about different secondary particles in three aspects: angular, energy spectrum and current. These results are helpful to select the detector type and its location, determine its dynamic range matching different requirements for both fast and slow beam loss. This paper also analyzes the major impact of the background, such as superconducting cavity X radiation and radiation caused by material activation. This work is meaningful in BLM system research.  
 
TUPF07 Covariance and Temporal Causality in the Transition Radiation Emission by an Electron Bunch electron, transverse, longitudinal, ITY 511
 
  • G.L. Orlandi
    PSI, Villigen PSI, Switzerland
  
  A model of the transition radiation emission by a N electron bunch must conform to covariance and causality. The covariance of the charge density must imprint the transition radiation energy spectrum via a proper formulation of the charge form factor. The emission phases of the radiation pulse must be causality correlated with the temporal sequence of the N electron collisions onto the metallic screen. Covariance and temporal causality are the two faces of the same coin: failing in implementing one of the two constraints into the model necessarily implies betraying the other one. The main formal aspects of a covariance and temporal-causality consistent formulation of the transition radiation energy spectrum by an N electron beam are here described. In the case of a transition radiator with a round surface, explicit formal results are presented.  
 
TUPF17 Phase Space Measurement using X-ray Pinhole Camera at SSRF emittance, storage-ring, photon, quadrupole 539
 
  • K.R. Ye, J. Chen, Z.C. Chen, G.Q. Huang, Y.B. Leng, L.Y. Yu, W.M. Zhou
    SINAP, Shanghai, People's Republic of China
  
  Since 2009 an X-ray pinhole camera that has been used to present the transverse beam size on diagnostic beamline of the storage ring in Shanghai Synchrotron Radiation Facility (SSRF). Transverse beam profiles in the real(x,y) and phase(Y,Y’) spaces are obtained by an X-ray pinhole camera sensitive by moving one pinhole. The large amount of collected data has allowed a detailed reconstruction of the transverse phase space evolution in this paper. An image on a fluorescent screen is observed by a CCD camera，digitized and stored, then the phase space and the real space profiles are reconstructed．A non-linear least square program fits the resultant profiles to a vertical dimensional Gaussian distributions to derive the phase space and emittances for SSRF storage ring．  
 
TUPF18 Vertical Undulator Emittance Measurement: A Statistical Approach undulator, emittance, photon, electron 543
 
  • K.P. Wootton, R.P. Rassool
    The University of Melbourne, Melbourne, Australia
  • M.J. Boland, B.C.C. Cowie, R.T. Dowd
    SLSA, Clayton, Australia
  
  Direct measurement of low vertical emittance in storage rings is typically achieved via interferometric techniques. Proof of low vertical emittance is demonstrated by the measurement of a null radiation field, which is also the crux of the vertical undulator emittance measurement. Here we present strategies to improve the sensitivity to low vertical emittance beams. We move away from photon spectrum analysis to a statistical analysis of undulator radiation, showing the measured increase in signal-to-background. Reproducing simulations of previous work, we demonstrate that photon beam polarisation extends the linearity of the technique by several decades in emittance. These statistical and polarisation improvements to the signal-to-background allow realistic measurement of smallest vertical emittance.  
poster icon Poster TUPF18 [2.090 MB]  
 
TUPF19 APPLE-II Undulator Magnetic Fields Characterised from Undulator Radiation undulator, emittance, photon, insertion 546
 
  • K.P. Wootton, R.P. Rassool
    The University of Melbourne, Melbourne, Australia
  • M.J. Boland, B.C.C. Cowie
    SLSA, Clayton, Australia
  
  The spatial profile of APPLE-II undulator radiation has been measured at high undulator deflection parameter, high harmonic and very small emittance. Undulators are typically designed to operate with small deflection parameter to push the fundamental mode to high photon energies. This unusual choice of parameters is desirable for measurement of vertical emittance with a vertical undulator. We present 1-D and 2-D measured profiles of undulator radiation, and show that this is reproduced in numerical models using the measured magnetic field of the insertion device. Importantly these measurements confirm that for these parameters, the spatial intensity distribution departs significantly from usual Gaussian approximations, instead resembling a double-slit diffraction pattern. This could be an important consideration for photon beamlines of ultimate storage ring light sources.  
poster icon Poster TUPF19 [2.364 MB]  
 
TUPF21 Response of Scintillating Screens to Fast and Slow Extracted Ion Beams ion, extraction, target, GSI 553
 
  • A. Lieberwirth, W. Ensinger
    TU Darmstadt, Darmstadt, Germany
  • P. Forck, B. Walasek-Höhne
    GSI, Darmstadt, Germany
  
  Funding: Funded by German Ministry of Science (BMBF), contract number 05P12RDRBJ
For the FAIR project, imaging properties of inorganic scintillators for high energetic heavy ion beams were studied. In order to investigate the characteristics of scintillation response and transverse beam profile, several experiments were conducted with slow (200 ms) and fast (1 μs) extracted 350 MeV/u Uranium beams from SIS18. The extracted particle number was varied between 105 and 109 particles per pulse for the irradiation of seven different scintillators: YAG:Ce-crystals with different qualities, pure and Cr-doped alumina as well as two phosphors P43 and P46. Additionally radiation resistance tests for all phosphor screens and the Cr-doped alumina screen were performed by irradiating with more than 700 pulses with 109 ions each. Linear response in scintillation light output as well as realistic statistical moments over the large range of ion intensities are presented for each material. Only minor changing in target response was observed after 45 minutes of permanent irradiation. 		 
poster icon Poster TUPF21 [2.601 MB]  
 
TUPF22 Beam Halo Monitor Based on an HD Digital Micro Mirror Array controls, laser, monitoring, transverse 557
 
  • B.B.D. Lomberg, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • B.B.D. Lomberg, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Funding: This work is supported by the European Union under contract PITN-GA-2011-289485 and by STFC under the Cockcroft Institute Core Grant No. ST/G008248/1.
A beam halo monitor is an essential device to pursue studies of halo particles produced in any particle accelerator as to investigate the effects of disturbances, such as field kicks, gradient errors, etc. A fast, least intrusive, high dynamic range monitor will allow the detection and potentially control of particles at the tail of a transverse beam distribution. Light generated by a beam of charged particles is routinely used for beam diagnostic purposes. A halo monitor based on a digital micro-mirror device (DMD) used to generate an adaptive optical mask to block light in the core of the emitted light profile and hence limit observation to halo particles has been developed in close collaboration with CERN and University of Maryland. In this contribution an evolution of this monitor is presented. A high definition micro-mirror array with 1920x1080 pixels has been embedded into a MATLAB-based control system, giving access to even higher monitor resolution. A masking algorithm has also been developed that automates mask generation based on user-definable thresholds, converts between CCD and DMD geometries, processes and analyses the beam halo signal and is presented in detail. 		 
poster icon Poster TUPF22 [1.558 MB]  
 
TUPF33 Electron Beam Diagnostics Using Radiation from a Free Electron Laser electron, space-charge, plasma, FEL 593
 
  • M. Arbel
    H.I.T., Holon, Israel
  • A. Eichenbaum
    Ariel University Center of Samaria, Faculty of Engineering, Ariel, Israel
  
  In most devices based on a high energy electron beam, which used for electromagnetic radiation production, great efforts are focused on the electron beam quality improvement. This is the case in a Free-Electron Laser (FEL) where electron beam with a low normalized emittance is required. Thus, diagnostic tools are required to investigate e-beam properties, such as beam emittance, longitudinal space charge, energy spread and velocity spread. In this paper we present analysis of radiation measurements obtained from a pre-bunched e-beam FEL. The measurements were made for a wide range of frequencies and for beam currents from low currents to high currents, where space charge effects can not neglected. We apply a frequency domain formulation to analyze the measured radiation. The spectral signature of the radiation emission obtained from a pre-bunched e-beam can provide vital information on e-beam properties. We show that a rigorous analysis of the measured radiation, allows characterization of the e-beam parameters. This analysis can provide some insights to the development of e-beam accelerators and radiation sources devices and to help physicists interpreting radiated signals.  
 
WEAL3 Diffraction Radiation Test at CesrTA for Non-Intercepting Micron-Scale Beam Size Measurement target, electron, CLIC, CERN 619
 
  • L.M. Bobb, E. Bravin, T. Lefèvre, S. Mazzoni
    CERN, Geneva, Switzerland
  • 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
    JAI, Egham, Surrey, United Kingdom
  
  Diffraction radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The electric field of the charged particle polarizes the target atoms which then oscillate, emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to a range of electron beam parameters. Furthermore, the energy loss due to DR is so small that the electron beam parameters are unchanged. DR can therefore be used to develop non-invasive diagnostic tools. To achieve the micron-scale resolution required to measure the transverse (vertical) beam size using incoherent DR in CLIC, DR in UV and X-ray spectral-range must be investigated. Experimental validation of such a scheme is ongoing at CesrTA at Cornell University, USA. Here we report on the test using 0.5 mm and 1 mm target apertures on a 2.1 GeV electron beam and 400 nm wavelength.  
slides icon Slides WEAL3 [2.893 MB]  
 
WECL2 Radiation Damages and Characterization in the SOLEIL Storage Ring quadrupole, dipole, vacuum, SOLEIL 644
 
  • N. Hubert, P. Brunelle, N. Béchu, L. Cassinari, C. Herbeaux, S. Hustache, J.-F. Lamarre, P. Lebasque, F. Marteau, A. Nadji, L.S. Nadolski
    SOLEIL, Gif-sur-Yvette, France
  
  After six years of operation, equipment located close to some vacuum chambers of the SOLEIL storage ring show unexpected damages due to radiation. It has been pointed out that, inside the so called “quadrupole” vacuum chambers, fluorescence X-rays are emitted by the materials that intercept upstream dipole synchrotron radiation. The energy of the emitted X-ray is too high to be significantly attenuated by the aluminum of which the vacuum chamber is made. Diagnostics and means used to characterize this radiation are presented, and measurements are compared to calculations.  
slides icon Slides WECL2 [2.336 MB]  
 
WECL3 The LUPIN Detector: Supporting Least Intrusive Beam Monitoring Technique Through Neutron Detection beam-losses, monitoring, proton, synchrotron 648
 
  • G.P. Manessi, M. Silari
    CERN, Geneva, Switzerland
  • M. Caresana
    Politecnico/Milano, Milano, Italy
  • M. Ferrarini
    CNAO Foundation, Milan, Italy
  • G.P. Manessi, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • G.P. Manessi, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  The Long interval, Ultra-wide dynamic Pile-up free Neutron rem counter (LUPIN) is a novel detector initially developed for radiation protection purposes, specifically conceived for applications in pulsed neutron fields. The detector has a measurement capability varying over many orders of neutron burst intensity, from a single neutron up to thousands of interactions for each burst, without showing any saturation effect. Whilst LUPIN has been developed for applications in the radiation protection fields, its unique properties make it also well suited to support other beam instrumentation. In this contribution, the design of LUPIN is presented in detail and its main characteristics are summarized. Its potential use as beam loss monitor and complementary detector for non-invasive beam monitoring purposes (e.g. to complement a monitor based on proton beam “halo” detection) in medical accelerators is then examined. In the context of its application as a beam loss monitor for hadrontherapy accelerators, results of measurements performed at the Italian National Centre of Hadrontherapy (CNAO) are presented and analyzed.  
slides icon Slides WECL3 [1.431 MB]  
 
WEPC03 Brookhaven 200 MeV Linear Accelerator Beam Instrumentation Upgrade linac, instrumentation, diagnostics, vacuum 656
 
  • O. Gould, B. Briscoe, D.M. Gassner, V. LoDestro, R.J. Michnoff, J. Morris, D. Raparia, K. Sanders, W. Shaffer, C. Theisen, M. Wilinski
    BNL, Upton, Long Island, New York, USA
  • D. Persaud
    City College of The City University of New York, New York, USA
  
  The Brookhaven National Laboratory 200 MeV H− LINAC beam instrumentation equipment has been in operation for four decades with various changes implemented over this period. There is a need to upgrade the entire beam instrumentation system of the LINAC to improve the diagnostics of the beam from the Low Energy Beam Transport Line through the LINAC and into the LINAC Booster Transfer Line and BLIP line. Profile Monitors, Current Monitors, Beam Position Monitors, Loss Radiation Monitors, and Emittance Measurement devices are to be designed and implemented over the next three years. This upgrade will improve the operation reliability, beam quality and beam losses. Additional improvements will be obtained by designing the beam instrumentation system to integrate with other proposed diagnostics and malfunction detection and display upgrades in the LINAC Control Room to improve the overall performance of the LINAC.  
poster icon Poster WEPC03 [18.356 MB]  
 
WEPC11 Radiation Resistance Testing of Commercial Components for the New SPS Beam Position Measurement System SPS, CERN, beam-position, BPM 686
 
  • C. Deplano, J. Albertone, T.B. Bogey, J.L. Gonzalez, J.-J. Savioz
    CERN, Geneva, Switzerland
  
  A new Front-End (FE) electronics is under development for the SPS Multi Orbit POsition System (MOPOS). To cover the large dynamic range of beam intensities (70dB) to be measured in the SPS, the beam position monitor signals are processed using logarithmic amplifiers. They are then digitized locally and transmitted via optical fibers over long distances (up to 1km) to VME acquisition boards located in surface buildings. The FE board is designed to be located in the SPS tunnel, where it must cope with a radiation dose rate of up to 100 Gy per year. Analogue components, such as Logarithmic Amplifiers, ADC-Drivers and Voltage regulators, have been tested at PSI for radiation hardness, while several families of bidirectional SFP, both single-fiber and double-fiber, have been tested at both PSI and CNRAD. This paper gives a description of the overall system architecture and presents the results of the radiation hardness tests in detail.  
poster icon Poster WEPC11 [3.299 MB]  
 
WEPC35 Progress Report of the Spectral Decoding Based EOS with Organic Pockels EO Crystals electron, laser, background, LEFT 765
 
  • Y. Okayasu, S. Matsubara, H. Tomizawa
    JASRI/SPring-8, Hyogo-ken, Japan
  • T. Matsukawa, H. Minamide
    RIKEN ASI, Sendai, Miyagi, Japan
  • K. Ogawa
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  
  Funding: Grant-in-Aid for Scientific Research (Japan Society for the Promotion of Science, Grants No. 20612024 and No. 23360045)
So far, the temporal structure of ultrashort electron bunches has been extensively investigated by various kinds of electro-optic sampling (EOS) techniques, such as temporal, spectral and spatial decoding method, at several FEL accelerator facilities since early 2000’s. Inorganic Pockels EO crystals, i.e., GaP and ZnTe, have been generally utilized for the EOS. On the other hand, since mid-1980’s, organic nonlinear optical materials have been extensively investigated and DAST*, which has fast temporal response in the EO effect, was developed in 1986**. DAST is transparent in visible near to IR wavelength range and absorbent in 0.8-1.3 THz. We introduced the DAST crystal into the EOS and successfully demonstrated the first observation of the bunch charge distribution at the EUV-FEL accelerator, SPring-8 on February 2012***. Through the previous experiment, it is found that the EO signal intensity was gradually decreased. On March and April 2013, we prepared DAST crystals with variety of thickness and succeeded to compare EO signal intensities with different bunch charges. Recent results of both optical and structural analysis will be reported in addition to experimental results.
*4-N, N-dimethylamino-4’-N’-methyl stilbazolium tosylate
**S. Okada et al., Japan Patent Application 61-192404 (1986)
***Y. Okayasu et al., Phys. Rev. ST Accel. Beams 16, 052801 (2013)
 		 
 
WEPC36 Development of Electron Bunch Compression Monitors for SwissFEL electron, longitudinal, synchrotron, transverse 769
 
  • F. Frei, B. Beutner, I. Gorgisyan, R. Ischebeck, G.L. Orlandi, P. Peier, E. Prat, V. Schlott, B. Smit
    PSI, Villigen PSI, Switzerland
  • P. Peier
    DESY, Hamburg, Germany
  
  SwissFEL will be a hard x-ray fourth generation light source to be built at Paul Scherrer Institut (PSI), Switzerland. In SwissFEL the electron bunches will be produced with a length of 3ps and will then be compressed by a factor of more than 1000 down to a few fs in order to generate ultra short x-ray pulses. Therefore reliable, accurate and noninvasive longitudinal diagnostic is essential after each compressing stage. In order to meet the requirements of this machine, new monitors have to be developed. We will present recent results of setups that measure electro-magnetic radiation, namely edge, synchrotron and diffraction radiation, emitted by the electron bunches (far field, spectral domain). These monitors are tested in the SwissFEL Injector Test Facility. A state of the art S-band Transverse Deflecting Cavity together with a Screen Monitor is used for calibration.  
 
WEPF05 An Electron Beam Detector for the FLASH II Beam Dump electron, vacuum, target, laser 814
 
  • F. Perlick, J.D. Good, N. Leuschner, M. Sachwitz
    DESY Zeuthen, Zeuthen, Germany
  • G. Kube, M. Schmitz, K. Wittenburg, T. Wohlenberg
    DESY, Hamburg, Germany
  
  For the electron absorber at FLASH II a detector is developed to control the position, dimensions and profile of the electron beam. Scintillation light, emitted from a luminescent screen in front of the dump window, is reflected by a mirror, located in 2 m distance from the screen, and passes through a vacuum window. Two different optical systems will be installed redundantly for beam image transfer: a conventional lens-mirror-system and a system using a radiation-hard optical fibre bundle. A CCD camera, located in one and a half meter distance from the beam line, is used for the optical analysis. An experimental setup, where the terms of installation of the components correspond to the FLASH accelerator, has been built up in a lab to coordinate the interaction of the screen with the components of the optical system. It was shown that the resolution of the lens-mirror-system is about one line pair per millimeter. An experiment is set up to test the impact of radiation on the optical qualities of the fibre optic bundle by installing it onto a “radioactive hot spot” at the bunch compressor in the FLASH accelerator.  
poster icon Poster WEPF05 [1.926 MB]  
 
WEPF18 Zemax Simulations of Diffraction and Transition Radiation simulation, OTR, target, electron 852
 
  • T. Aumeyr, P. Karataev
    JAI, Egham, Surrey, United Kingdom
  • M.G. Billing
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • L.M. Bobb, B. Bolzon, T. Lefèvre, S. Mazzoni
    CERN, Geneva, Switzerland
  
  Diffraction Radiation (DR) and Transition Radiation (TR) are produced when a relativistic charged particle moves in the vicinity of a medium or through a medium respectively. The target atoms are polarised by the electric field of the charged particle, which then oscillate thus emitting radiation with a very broad spectrum. The spatial-spectral properties of DR/TR are sensitive to various electron beam parameters. Several projects aim to measure the transverse (vertical) beam size using DR or TR. This paper reports on how numerical simulations using Zemax can be used to study such a system.  
poster icon Poster WEPF18 [0.573 MB]  
 
WEPF22 Non Invasive Optical Synchrotron Radiation Monitor Using a Mini-Chicane emittance, electron, diagnostics, space-charge 860
 
  • R.B. Fiorito, R.A. Kishek, A.G. Shkvarunets
    UMD, College Park, Maryland, USA
  • D. Castronovo, M. Cornacchia, S. Di Mitri, M. Veronese
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • C. Tschalär
    MIT, Middleton, Massachusetts, USA
  
  Funding: Office of Naval Research and DOD Joint Technology Office
We are developing a design for a minimally perturbing mini-chicane which utilizes the optical synchrotron radiation (OSR) generated from magnetic bends to measure the rms emittance and other optical parameters of the beam. The beam is first externally focused at the first bend and the OSR generated there is used to image the beam. Subsequently, any pair of bends produces interferences (OSRI) whose visibility can used to determine the beam divergence. The properties of different configuration of bends in the chicane have been analyzed to provide an optimum diagnostic design for a given set of beam parameters which: 1) provides a sufficient number of OSRI fringes to allow a measurement of the beam divergence; 2) minimizes the competing effect of energy spread on the fringe visibility; 3) minimizes the effect of coherent synchrotron radiation and space charge on the beam emittance; and 4) minimizes the effect of compression on the bunch length, as the beam passes through the chicane. Diagnostic designs have been produced for 100-300 MeV beams with a normalized rms emittance of about 1 micron for application to Fermi@Elettra and similar high brightness free electron lasers. 		 
poster icon Poster WEPF22 [0.642 MB]  
 
WEPF23 Beam Diagnostics R&D within oPAC diagnostics, OTR, transverse, simulation 864
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  Funding: oPAC is funded by the European Commission under Grant Agreement Number 289485.
Optimization of particle accelerators by combining research into beam physics, beam instrumentation, accelerator control systems and numerical simulation studies is the goal of the oPAC project. Supported with 6 Million Euros by the European Union, the network is one of the largest-ever Initial Training Networks. During the project's four year duration 22 fellows will be trained and a very broad international training program, consisting of schools, topical workshops and conferences will be organized by a consortium of currently more than 30 partner institutions. In this contribution, we will give an overview of oPAC's broad beam diagnostics R&D program, comprising absolute beam intensity measurements for low energy beams, beam diagnostics for synchrotron light sources, cyrogenic beam loss monitors, beam halo monitoring and 3D dose measurements as part of intensity modulated radiotherapy treatment. We will also summarize past oPAC events and give an outlook on future events. 		 
 
WEPF27 Coherent Ultraviolet Radiation Measurements of Laser Induced Bunching in a Seeded FEL laser, bunching, FEL, electron 879
 
  • M. Veronese, A. Abrami, E. Allaria, M. Ferianis, E. Ferrari, M. Trovò
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • F. Cianciosi
    ESRF, Grenoble, France
  
  Optimization of the bunching process in a seeded FEL like FERMI@Elettra is an important aspect for machine operation. In this paper we discuss about the power detection of coherent radiation in the UV range as a valuable method for optimizing the bunching induced by the seeding process on the electron beam. Experimental results obtained at FERMI@Elettra are presented here. Measurements of UV coherent transition and diffraction radiation have been used to quantify the bunching produced by the seed laser at lower laser harmonics. The dependence of the laser induced CUVTR signal on various parameters is experimentally studied. Future upgrades and possibilities for bunching measurements at shortest wavelengths are also discussed.  
 
WEPF34 Accurate Measurement of Small Electron Beam Currents at the MLS Electron Storage Ring electron, storage-ring, synchrotron, synchrotron-radiation 903
 
  • R. Klein, G. Brandt, D. Herzog, R. Thornagel
    PTB, Berlin, Germany
  
  The PTB, the German metrology institute, utilizes the electron storage ring MLS in Berlin Adlershof for the realization of the radiometric units in ultraviolet and vacuum ultraviolet spectral range. For this purpose the MLS can be operated as a primary source standard of calculable synchrotron radiation with very flexible parameters, especially in terms of electron beam energy and electron beam current. We report on improvements in the measurement of the electron beam current in the nA and pA range. In this range the electron beam current can be very accurately measured by counting the stored electrons.  
 
WEPF36 X-ray Cherenkov Radiation as a Source for Relativistic Charged Particle Beam Diagnostics polarization, electron, photon, target 910
 
  • A.S. Konkov, A.S. Gogolev, A. Potylitsyn
    TPU, Tomsk, Russia
  • P. Karataev
    Royal Holloway, University of London, Surrey, United Kingdom
  
  Funding: The work was partially supported by Russian Ministry of Science and Education within the grant No. 14.B37.21.0912.
Recent progress in development of accelerator technology for future linear colliders and X-ray free electron lasers has generated an interest in developing novel diagnostics equipment with resolution surpassing the unique beam parameters. Cherenkov radiation (CR) in the X-ray region in the vicinity of the absorption edges is one of the promising sources for relativistic charged particle beam diagnostics. In this work we have demonstrated CR characteristics in the X-ray region significantly depend on the energy of the emitted photons, because the CR is only generated in the frequency region in the vicinity of the atomic absorption edges, where the well-known Cherenkov condition is work. This peculiarity can be explained by resonance behaviour of the permittivity in the frequency range. It will result in the fact that the CR will stand out of any other types of polarisation radiation both on intensity and shape of angular distribution giving a unique opportunity to apply this phenomenon for charged particle beam diagnostics. 		 
poster icon Poster WEPF36 [42.675 MB]