Transverse Profiles, Screens & Wires Monitors
Paper Title Page
MOCC01
 UV/X-ray Diffraction Radiation for Non-intercepting Micron-scale Beam Size Measurement  
 
  • L.M. Bobb, N. Chritin, T. Lefèvre
    CERN, Geneva, Switzerland
  • M.G. Billing
    CLASSE, Ithaca, New York, USA
  • L.M. Bobb, V. Karataev
    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. Therefore DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in the UV and X-ray spectral-range must be investigated. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. Here we present the current status of the experiment preparation.  
slides icon Slides MOCC01 [3.064 MB]  
 
MOCC04
 Improvement of Screen Monitor with Suppression of Coherent-OTR for SACLA  
 
  • S. Matsubara, Y. Otake
    RIKEN/SPring-8, Hyogo, Japan
  • S.I. Inoue
    SES, Hyogo-pref., Japan
  • H. Maesaka
    RIKEN Spring-8 Harima, Hyogo, Japan
  
  The construction of SACLA (SPring-8 Angstrom Compact free electron LAser) was already completed and it is under operation. A screen monitor (SCM) system has been developed and was installed in order to obtain a direct image of a transverse beam profile with a spatial resolution of about 10 um, which is required to investigate electron-beam properties, such as a beam emittance. The SCM originally has a stainless steel target as a OTR radiator or a Ce:YAG crystal as a scintillation target. At the beginning of the SACLA operation, strong coherent OTR (COTR), which made an incorrect beam profile, was observed after bunch compressors. In order to suppress the COTR on the SCM, the stainless steel target was replaced to the Ce:YAG scintillation target. Since the COTR was still generated from the Ce:YAG target, a spatial mask was employed. The mask was mounted on the center of the optical line of the SCM, because the COTR light is emitted forward within ~1/γ radian, while the scintillation light has not angular dependence. Clear beam profiles with a diameter of a few tens of micro-meter are observed by means of the SCMs with this simple improvement.  
 
MOPB67
 Development of Offner Relay Optical System for OTR Monitor at 3-50 Beam Transport Line of J-PARC  
 
  • M. Tejima, T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  • Y. Hashimoto, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • S. Otsu
    MELCO SC, Tsukuba, Japan
  
  An extremely wide aperture relay optical system based on Offner system has been designed and constracted for OTR monitor at 3-50 beam transport line of J-PARC. Diagnostics for beam profile and halo are very important to optimize injection beam from RCS to MR in J-PARC. For this purpose, an OTR monitor is planed to install for an observation of image of the beam and halo after the beam collimators. Since opening of OTR is very wide due to small Gamma; 3.2, extremely wide aperture (500mrad) optics will necessary to extract OTR from file target. We designed Offner type relay optics for the effective extraction of OTR having F=0.83. The clear aperture will cover 100 x 100mm aria on the target screen. Results of optical testing and design of OTR monitor will present in this paper.  
 
MOPB68 Development of Profile Monitor System for High Intense Spallation Neutron Source 1
 
  • S.I. Meigo, A. Akutsu, M. Futakawa, K. Ikezaki, M. Ooi, S. Sakamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  At the JSNS in J-PARC, a mercury target is employed as the neutron production target. It is well known that the damage on the mercury target is promotional to the 4th power of the peak current density of the primary proton beam on the target. For the high intense neutron source, the profile on the target is important to drive the neutron source with the continuously observation of the profile. We have developed to Multi Wire Profile Monitor System (MWPM). During beam operation, when the abnormally of the beam is found, the beam is cut out by the Machine Protection System (MPS). For the measurement of the two dimension observation on the target, we have developed the system based on the residual radiation measurement by using an imaging plate (IP), It is found that the both result by the MWPM and IP shows good agreement.  
 
MOPB69
 Development of Four Mirror Pulsed Laser Wire System for ATF-KEK Damping Ring  
 
  • A.A. Rawankar, N. Terunuma, J. Urakawa
    Sokendai, Ibaraki, Japan
  • A.S. Aryshev, Y. Honda, H. Shimizu
    KEK, Ibaraki, Japan
  • Y. You
    TUB, Beijing, People's Republic of China
  
  Funding: Quantum Beam Technology Program of Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT).
Production and handling of a low emittance beam is one of the key technologies for linear colliders. The Accelerator Test Facility (ATF) was constructed at KEK to study low emittance beam physics and to develop the technologies associated with it. In ATF damping ring, the vertical beam size is less than 10 μm. To measure it precisely, a thin and intense laser beam is required. We utilize a pulsed four mirror optical cavity based on IR laser oscillator to fulfill this requirement. With pulsed green laser oscillator, the beam waist will reduce by factor of 2. Therefore, with green laser oscillator, effective electron-photon collision can be observed. Minimum beam waist is obtained in sagittal plane. Special type of mirror alignment scheme is used to make a compact four mirror optical cavity. With Pulsed laser oscillator the electron beam scanning is very fast as compare to CW Laser wire system. Profile of electron beam can be measured in vertical, horizontal and longitudinal direction within a few second. We report the design studies of such compact resonator and scheme to obtain laser beam size less than 6μm in rms. 		 
 
MOPB70 The Synchrotron Radiation Diagnostic Line at SSRF 1
 
  • J. Chen, Z.C. Chen, G.Q. Huang, Y.B. Leng, K.R. Ye, W.M. Zhou
    SINAP, Shanghai, People's Republic of China
  
  The synchrotron radiation photon beam line has been operated since 2009 at Shanghai Synchrotron Radiation Facility. There are two diagnostic beam lines of the storage ring behind bending magnet, which is employed conventional X-ray and visible imaging techniques. A synchrotron radiation (SR) interferometer using visible light region in order to measure the small transverse electron beam size (about 22μm); low emittance and a low coupling. A small off-axis mirror is set for the convenience of the observation. Wave front testing is used for interferometer to calibrate the deformation effect of optical components. An X-ray pin-hole camera is also employed in the diagnostics beamline of the ring to characterize beam. Typically the point spread function of the X-ray pinhole camera is calculated via analytical or numerical method. Those two methods check each other. As a result, the measurement with SR system has quite enough resolution of itself even though the absolute beam size acquired. The existed system suffers with dynamic problem for beam physics studies. It has been measured 2.8nm.rad in small emittance mode at SSRF.  
 
MOPB72 First Measurements with Coded Aperture X-ray Monitor at the ATF2 Extraction Line 1
 
  • J.W. Flanagan, A. Arinaga, H. Fukuma, H. Ikeda, T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  • G.S. Varner
    University of Hawaii, Honolulu, HI, USA
  
  Funding: Kakenhi
The ATF2 extraction line is used as a test-bed for technologies needed for the ILC final-focus region. An x-ray extraction beam line has been constructed at the final upstream bend before the extraction line straight section, for development and testing of optics and readout systems for a coded aperture-based imaging system. The x-ray monitor is expected to eventually be able to measure single-shot vertical bunch sizes down to a few microns in size at its source location in the ATF2 extraction line. Preliminary scanned measurements have been made with beams in the ~15 micron range, and it is planned to make more measurements with further-tuned beam, and with fast read-out electronics. The details of the layout, expected performance, and preliminary measurement results will be presented. 		 
 
MOPB73 Beam Size and Intensity Diagnostics for a SRF Photoelectron Injector 1
 
  • R. Barday, A. Jankowiak, T. Kamps, A.N. Matveenko, M. Schenk, J. Völker
    HZB, Berlin, Germany
  • F. Siewert
    BESSY GmbH, Berlin, Germany
  • J. Teichert
    HZDR, Dresden, Germany
  
  Funding: Work supported by Bundesministerium für Bildung und Forschung and Land Berlin
A high brightness photoelectron injector must be developed as a part of the BERLinPro program. The injector is designed to produce an electron beam with 100 mA average current and a normalized emittance of 1 mm*mrad. The project will be realized in two stages. First with a Pb cathode in a SRF gun, work ongoing, followed by a normal conducting CsK2Sb cathode capable of generating high current beams. In the first stage we have measured the fundamental beam parameters bunch charge, beam energy and energy spread with a special focus on the measurement of the transverse beam profiles. We also discuss our plans for the beam characterization at high currents. 		 
 
MOPB74
 Beam Measurement with Synchrotron Radiation for BEPCII Storage Ring  
 
  • L. Wang, J. Cao, Z. Zhao
    IHEP, Beijing, People's Republic of China
  
  The detail of Synchrotron Light Monitor for BEPCII storage ring is introduced. The Synchrotron Light Monitor measures both transverse beam profiles and longitudinal bunch length. Transverse profiles are measured by visible light imaging and spatial interferometer, and longitudinal bunch length is measured by streak cemera and intensity interferometer.  
 
MOPB75 Real-time Beam Profile Measurement System using Fluorescent Screens 1
 
  • T. Yuyama, I. Ishibori, T. Ishizaka, S. Okumura, Y. Yuri
    JAEA/TARRI, Gunma-ken, Japan
  
  In the TIARA AVF cyclotron facility of JAEA, we are developing an irradiation technique of a large-area uniform ion beam formed by nonlinear focusing using multipole magnets. It is indispensable to perform beam tuning and evaluation of the beam quality at the same time for efficient operation. Therefore, we developed a real-time beam profile measurement system composed of two CCD cameras, fluorescent screens, and an image analysis program based on LabVIEW. In order to measure the transverse intensity distribution of the beam through the luminance map converted from a camera image, the characteristics of fluorescent screens, DRZ (Gd2O2S:Tb) and AF995R (Al2O3:Cr), were investigated using several species of ion beams. It was found that the light yield from the DRZ-HIGH screen irradiated with 10 MeV H+ beam was increased linearly with the particle fluence rate from 5×107 to 5×108 [cm-2･s−1] and that the relative transverse intensity distribution could be obtained from the fluorescence in real time. It was also confirmed that the intensity distribution measured in this system agreed well with the relative intensity distribution obtained with a Gafchromic radiochromic film.  
 
MOPB76 Evaluation of a Fluorescent Screen with a CCD System for Quality Assurance in Heavy-Ion Beam Scanning Irradiation System 1
 
  • Y. Hara, T. Furukawa, T. Inaniwa, K. Mizushima, K. Noda, S. Sato, T. Shirai, E. Takeshita
    NIRS, Chiba-shi, Japan
  
  The precise heavy-ion therapy such as the scanning irradiation system necessitates the precise quality assurance (QA) procedures to verify the performance of therapeutic scanned ion beams. To evaluate the uniformity of the 2D field, radiographic film is used due to its high spatial resolution and suit for the measurements of the integral dose. However, this technique is time consuming. Thus, we developed the QA tool with high spatial resolution to verify accuracy of the lateral size, position and uniformity of scanned ion beams in clinical application at the HIMAC, which we called the QA-SCN. The QA-SCN consists of a fluorescent screen, a CCD camera, a mirror, camera controllers and a dark box to protect against surrounding light. In this paper, to evaluate the performance of the QA-SCN, we compared the results obtained by using it with the measurements by radiographic film performed in the same experimental conditions. Also, we verified several types of corrections about errors, e.g. background, vignetting, to distort the measurement results. As a result, we confirmed that the QA-SCN can be used as the system for QA procedures of therapeutic scanned ion beams.  
 
MOPB77 Adjustable Optics for a Non-destructive Beam Profile Monitor based on Scintillation of Residual Gas 1
 
  • K. Reimers, V. Kamerdzhiev, A. Pernizki
    FZJ, Jülich, Germany
  
  The scintillation profile monitor (SPM) is being developed at COSY in addition to the existing ionisation profile monitor (IPM). Contrary to the IPM it does not require in-vacuum components, making it a robust and inexpensive instrument. The SPM is suitable for high intensity operation rather than operation with low intensity polarised beams. A multichannel PMT is used to detect scintillation light. The rate of detectable scintillation events is about three orders of magnitude lower compared to the rate of ionisation events. To boost the photon yield, small amounts of nitrogen are injected into the SPM vacuum chamber. An adjustable light focusing system is being built to optimise the SPM performance for different machine operation modes. The new system allows using a variety of optical components ranging from single lenses to high-grade camera objectives. Cylindrical lenses are considered to further boost the sensitivity by better fitting the beam image to the detector geometry. The latest experimental results and the new design of the optical system are presented.  
 
MOPB78 Beam Spot Measurement using a Phosphor Screen for Carbon-Ion Therapy at NIRS 1
 
  • K. Mizushima, T. Furukawa, Y. Hara, K. Katagiri, K. Noda, T. Shirai, E. Takeshita
    NIRS, Chiba-shi, Japan
  
  A two-dimensional beam imaging system with a terbium-doped gadolinium oxysulfide (Gd2O2S:Tb) phosphor screen and high-speed charge coupled device (CCD) camera has been used to measure the beam spot for scanned carbon-ion therapy at National Institute of Radiological Sciences (NIRS). The system enables us to obtain one image of the beam spot every 20 milliseconds. The fluctuation of the unscanned-beam spot size and position was observed in the isocenter to verify the time stability of the delivered beam for scanning irradiation. The beam imaging system also functions as a beam alignment adjustment system by setting a steel sphere at the isocenter. For quality assurance, the beam alignment is routinely checked by observing a shadow of the steel sphere on the beam spot image, and it is confirmed that the misalignment of the beam is smaller than the tolerance of 0.5 mm.  
 
MOPB79 Design of a High-precision Fast Wire Scanner for the SPS at CERN 1
 
  • R. Veness, N. Chritin, B. Dehning, J. Emery, J.F. Herranz Alvarez, M. Koujili, S. Samuelsson, J.L. Sirvent Blasco
    CERN, Geneva, Switzerland
  
  Studies are going on of a new wire scanner concept. All moving parts are inside the beam vacuum and it is specified for use in all the machines across the CERN accelerator complex. Key components have been developed and tested. Work is now focussing on the installation of a prototype for test in the Super Proton Synchrotron (SPS) accelerator. This article presents the specification of the device and constraints on the design for integration in the different accelerators at CERN. The design issues of the mechanical components are discussed and optimisation work shown. Finally, the prototype design, integrating the several components into the vacuum tank is presented.  
 
MOPB80 High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs 1
 
  • P. Evtushenko, D. Douglas
    JLAB, Newport News, Virginia, USA
  
  Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especially important for non-equilibrium beams in the LINACs. The measurements were made by means of simultaneous imaging with two CCD sensors with different exposure time. Two images are combined then numerically in to one HDR image. The system works as an online tool providing HDR images at 4 Hz. An optically polished YAG:Ce crystal with the thickness of 100 um was used for the measurements. When tested with a laser beam images with the DR of about 10+5 were obtained. With the electron beam the DR was somewhat smaller due to the limitations in the time structure of the tune-up beam macro pulse.  
 
MOPB81 Residual Gas Ionization Profile Monitors in J-PARC Slow-extraction Beam Line 1
 
  • Y. Sato, A. Agari, E. Hirose, M. Ieiri, Y. Katoh, M. Minakawa, R. Muto, M. Naruki, S. Sawada, Y. Shirakabe, Y. Suzuki, H. Takahashi, M. Takasaki, K.H. Tanaka, A. Toyoda, H. Watanabe, Y. Yamanoi
    KEK, Tsukuba, Japan
  • H. Noumi
    RCNP, Osaka, Japan
  
  Residual gas ionization profile monitors (RGIPMs) working in 1 Pa pressure have been developed for high-intensity proton beam (maximum: 50GeV-15uA) at J-PARC slow-extraction beam line. The transverse beam profiles are measured by collecting electrons produced by ionization of 1 Pa residual gas. The electrons are guided to the segmented electrode with a uniform electrostatic field applied in the gap. A uniform magnetic field is applied parallel to the electric field to reduce diffusion of electrons travelling to the electrodes. Typical spatial resolution of the RGIPMs with a 10 cm gap, a 10 V/cm electrostatic field, and a 400 gauss magnetic field at center is 0.5 mm. The collected charge is integrated during every extraction period (typically 2 second in 6 second accelerator cycle). Subtracting background distributions measured during off-beam period, profile distributions are measured clearly. The 14 RGIPMs installed in the slow-extraction beam line are working stably for the 30 GeV-0.46 uA proton beam at current maximum. In this contribution, detailed specifications and performance of the present RGIPMs will be reported.  
 
MOPB82 Bunch-Compressor Transverse Profile Monitors of the SwissFEL Injector Test Facility 1
 
  • G.L. Orlandi, M. Aiba, S. Bettoni, B. Beutner, H. Brands, R. Ischebeck, P. Peier, E. Prat, T. Schietinger, V. Schlott, V.G. Thominet
    PSI, Villigen, Switzerland
  • C. Gerth
    DESY, Hamburg, Germany
  
  The 250 MeV SwissFEL Injector Test Facility (SITF) is the test bed of the future 5.7 GeV SwissFEL linac that will drive a coherent FEL light source in the wavelength range 7-0.7 and 0.7-0.1 nm. Aim of the SITF is to demonstrate the technical feasibility of producing and measuring 10 or 200pC electron bunches with normalized emittance down to 0.25 μm. A further goal is to demonstrate that the electron beam quality is preserved in the acceleration process, in the X-Band linearizer and the magnetic compression from about 10 ps down to 200 fs. The SITF movable magnetic bunch-compressor is equipped with several CCD/CMOS cameras for monitoring the beam transverse profile and determining the beam energy spread: a Ce:YAG screen and an OTR screen camera at the mid-point of the bunch compressor and a SR camera imaging in the visible the Synchrotron Radiation emitted by the electron beam crossing the third dipole. Results on the commissioning of such instrumentations, in particular in the low charge limit, and measurements of the beam energy spread vs. the compression factor will be presented.  
 
MOPB83 Turn-by-turn Observation of the Injected Beam Profile at the Australian Synchrotron Storage Ring 1
 
  • M.J. Boland
    ASCo, Clayton, Victoria, Australia
  • T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  • K.P. Wootton
    The University of Melbourne, Melbourne, Australia
  
  A fast gated intensified CCD camera was used to observe the beam profile turn-by-turn in the visible light region. Using the visible light from the optical diagnostic beamline on the storage ring at the Australian Synchrotron an optical telescope was constructed to focus an image on the ICCD. The event driven timing system was then used to synchronise the camera with the injected beam. To overcome the problem of dynamic range between the amount of charge in an injected bunch and the stored beam, the beam was dumped by slowly phase flipping the RF by 180 degrees between each one 1 Hz injection cycle. The injection process was verified to be stable enough so that measurements of the different turns could be captured on successive injections and did not need to be captured in single shot. The beam was seen to come in relatively cleanly in a tight beam but would then rapidly decohere due to the strong non-linear fields needed to run the storage ring at high chromaticity. It would take thousands of turns for the beam to damp down again and recohere into a tight beam spot again. This measurement technique will be used to tune the storage ring injection process.  
 
TUPB67
 Test Measurements of Beam Profile Monitor at HIRFL-RIBLL2  
 
  • T.C. Zhao, Y.C. Feng, X.C. Kang, H.L. Li, M. Li, P. Li, R.S. Mao, Q. She, H. Su, J.W. Xia, G.Q. Xiao, Y.J. Yuan, W.N. ma, Z.G. xu
    IMP, Lanzhou, People's Republic of China
  
  The beam intensity supplied by HIRF-CSR has a wide range, high-intensity primary beams and low intensity fragment-beams in connection with the slow extraction and the fast beam-extraction from the synchrotron CSRm. The detector (CG) has been developed for the beam profile monitoring at radioactive beam line HIRFL-CSR. The front-end electronics are based on CPLD controlled sample-and-hold circuits and multiplexer. Remote control is used to tune the detector sensitivity by setting the gas pressure in the detector's cell, the bias voltage of the anode and the integration time. The test measurements results are presented in this paper. Keywords: beam profile monitor; current grids; multiplexer; HIRFL CSR;  
 
TUPB68
 A new Multi-strip Ionization Chamber used as On-line Beam Profile Monitor at HIRFL-CSR  
 
  • Z.G. Xu, Z.G. Hu, H.L. Li, M. Li, R.S. Mao, Q. She, H. Su, J.X. Wu, J.W. Xia, H.S. Xu, Y.J. Yuan, T.C. Zhao
    IMP, Lanzhou, People's Republic of China
  
  The beam extracted from CSRm is mainly used for heavy-ion tumor therapy and physics experiments with stable and radioactive ions. A position sensitive detector is usually implemented to monitor the primary beam online in the nuclear experiments. Meanwhile, the detector should be thin enough to reduce the influence of energy spread and beam purity. This paper describes the developing and building a new detector with position resolution better than 0.5mm (FWHM) and using metallic-membrane plating technology for sharp reducing electrode's thickness of detector. The sensitive area of the detector is (100×100)mm2, with 1mm strip pitch. The anodes, cathode and the sealed windows are all made by 2μm thick Mylar layer on which a 0.1μm thick film of aluminum has been plated. Total thickness of the detector is about 12μm.  
 
TUPB69 Numerical Analysis on the Gain-reduction Characteristics of Multi-wire Proportional Chambers 1
 
  • K. Katagiri, T. Furukawa, K. Noda
    NIRS, Chiba-shi, Japan
  
  Several MWPC (Multi-Wire Proportional Chamber) monitors are installed to diagnosis the beam profiles in the high-energy beam transport at HIMAC (Heavy Ion Medical Accelerator in Chiba) synchrotrons. When the intensity of the incident beams are much high, the gain reduction of the output signal from the MWPC monitor occurs due to the space charge effect of positive ions around the anode wires. The gain reduction is expected to be improved by changing geometric parameters, such as anode radius and distance between electrodes. In order to investigate the gain-reduction characteristics for different geometric parameters, we performed numerical simulation using a numerical code. The numerical code was developed using a two-dimensional drift-diffusion model to evaluate the gas gain including the reduction effect caused by the space charge effect of the moving positive ions. We investigate the gain-reduction rate for several parameters of the anode distance when changing the beam intensity. From these results, we discuss desirable distances between the anode wires to improve the gain reduction.  
 
TUPB70 The ATF2 Multi-OTR System: Studies and Design Improvements 1
 
  • J. Alabau-Gonzalvo, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós, J. Resta-López
    IFIC, Valencia, Spain
  • J. Cruz, D.J. McCormick, G.R. White, M. Woodley
    SLAC, Menlo Park, California, USA
  
  Funding: Funding Agency: FPA2010-21456-C02-01 Work supported in part by Department of Energy Contract DE-AC02-76SF00515.
A multi-Optical Transition Radiation system made of four stations has been installed in the extraction line of ATF2 and has been fully operational since September 2011. The system is being used routinely for beam size and emittance measurements as well as for coupling correction and energy spread measurements. In this paper we present the beam sizes and emittance measurements performed during 2012 runs as well as a detailed study of the experimental single-shot automated coupling correction and the comparison with the simulations. Wakefields problems experimented with the simultaneous measurement has been studied and will be solved by new target holders that will be installed in the next Fall 2012 run. 		 
 
TUPB72 Injected Beam Profile Measurement during Top-up Operation 1
 
  • M.J. Boland
    ASCo, Clayton, Victoria, Australia
  • T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  • K.P. Wootton
    The University of Melbourne, Melbourne, Australia
  
  A coronagraph-like apparatus was constructed on the optical diagnostic beamline on the storage ring to observe the injected beam during top-up operations. An image was created on an intensified CCD that can be gated on a single bunch or on a bunch train for a stronger signal. The bright central stored beam was obscured so the comparatively faint injected beam could be observed. The injected beam comes in at a large enough offset so that it was clearly visible above any diffraction or beam halo signals. The beam profile measured was in good agreement with the observations made of the injected beam only using a telescope apparatus. The measurements were made during user beam in top-up operation mode and can be used to optimise the injection process.  
 
TUPB73
 Development of a Beam Profile Monitor using Nitrogen-Molecular Jet for Intense Beams  
 
  • Y. Hashimoto, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • T. Fujisawa, T.M. Murakami, K. Noda
    NIRS, Chiba-shi, Japan
  • Y. Hori, S. Muto, K. Yoshimura
    KEK, Ibaraki, Japan
  • T. Morimoto
    Morimoto Engineering, Iruma, Saitama, Japan
  • D. Ohsawa
    Kyoto University, Radioisotope Research Center, Kyoto-shi, Japan
  
  Funding: This work was supported by MEXT/JSPS KAKENHI Grant Number of 24310079 (Grant-in-Aid for Scientific Research(B)).
A non-destructive beam profile monitor using a sheeted jet beam of nitrogen molecular as a target has been developed for intense ion beams. The pressure of the sheeted molecular beam was 5 x 10-4 Pa at the beam collision point. A light emitted from excited nitrogen by an ion beam collision is measured by a high sensitive camera with a radiation resistant image intensifier. Verification of such a principle was already demonstrated with low-energy ion beams[1]. In this paper, some actual designs for intense beams of the J-PARC MR will be discussed mainly as bellow, intensity upgrade of the jet beam production, configuration of the detection chamber and its apparatus placed beam collision point, and the optical system for the light detection.
*[1] Y. Hashimoto, et al., Proc. of IPAC'10, Kyoto, Japan, p.987-989. 		 
 
TUPB74 Diamond Mirrors for the SuperKEKB Synchtron Radiation Monitor 1
 
  • J.W. Flanagan, A. Arinaga, H. Fukuma, H. Ikeda
    KEK, Ibaraki, Japan
  
  The SuperKEKB accelerator, a 40x luminosity upgrade to the KEKB accelerator, will be a high-current, low-emittance double ring collider. The beryllium primary extraction mirrors used for the synchrotron radiation monitors at KEKB suffered from heat distortion due to incident synchrotron radiation, leading to systematic changes in magnification with beam current and necessitating continuous monitoring and compensation of such distortions in order to correctly measure the beam sizes. The heat loads on the extraction mirrors will be higher at SuperKEKB, with heat-induced magnification changes up to 40% expected if the same mirrors were used as at KEKB. We are working on a design based on mirrors made of quasi-monocrystalline diamond, which has much higher heat conductance and a lower thermal expansion coefficient than beryllium. With such mirrors it is targeted to reduce the beam current-dependent magnification effects to the level of a few percent at SuperKEKB. Measurements of heat-induced deformations on fabricated prototype mirrors will be presented, along with comparisons with the results of numerical simulations.  
 
TUPB75
 Design and Construction of SEM for Continues 200keV Electrostatic Accelerator  
 
  • M.Sh. Shafiee, E.E. Ebrahimibasabi, A.H. Feghhi
    sbu, Tehran, Iran
  • M. Jafarzadeh
    ILSF, Tehran, Iran
  
  Beam profile and position monitoring at continues beams aren't possible by electromagnetic based instruments such as Pick Up, by this regard, design and construction of SEM has done for 200 keV electrostatic machines which can be classified into mechanic and electronic sections. At mechanical section the vacuum chamber with 3 feed-through which each one has 32 pins was constructed then grids with 16 copper wire with length of 10 cm and 80 μm diameter at each vertical and horizontal direction considered. The produced signals amplified and then digitized by ADC and transferred by ATMEGA32 ports to PC which set by GUI (MATLAB) as data analyzer. Induced profile at quartz glass which is placed at the end of beam tube was considered as bench mark source. The electrical results were compared with the result of quartz as practical method and CST as simulation. high accuracy and precision deduced which is presented at this article.  
 
TUPB76 Intra Undulator Screen Diagnostics for the FERMI@Elettra FEL 1
 
  • M. Veronese, A. Abrami, E. Allaria, M. Bossi, A. Bucconi, M. De Marco, M. Ferianis, L. Fröhlich, L. Giannessi, S. Grulja, R. Sauro, C. Spezzani, M. Tudor
    ELETTRA, Basovizza, Italy
  • T. Borden
    FRIB, East Lansing, Michigan, USA
  • F. Cianciosi
    ESRF, Grenoble, France
  
  The FERMI@Elettra seeded FEL poses demanding requirements in terms of intra undulator diagnostics due to the short wavelength of its FEL radiation and to the coexistence of the electron and photon FEL beams. An advanced multi-beam screen system has equipped both FEL1 and FEL2. The system has been designed for transverse size and profile measurement on both the electron beam and the FEL radiation. Challenging design constrains are present: COTR suppression, seed laser suppression, FEL wavelength range and minimization of the ionizing radiation delivered to the undulators. This paper describes the novel design and the obtained performance with the FERMI intra undulator screen system (IU-FEL).  
 
TUPB77 Measurement of the Frequency Spectrum on the Beam Profile Controlled by RF Kicker 1
 
  • Y. Yamamoto
    Ritsumeikan University, Kusatsu-City, Shiga, Japan
  
  The frequency spectrum on the beam profile was measured at the compact superconducting storage ring of Ritsumeikan University. The radiation detector was used an avalanche photodiode module with a high frequency response of 1 GHz for the visible ray. Signals from the detector were transferred to a spectrum analyzer. The beam profile was magnified strongly by a conventional profile monitor system. We scanned the beam profile in vertical direction by shifting the detector. The distribution of peak intensity as a function of the position on beam profile was obtained.  
 
TUPB78 Flying Wire Beam Profile Monitors at the J-PARC MR 1
 
  • S. Igarashi, D.A. Arakawa, Y. Hashimoto, M. Tejima, T. Toyama
    KEK, Ibaraki, Japan
  • K. Hanamura
    MELCO SC, Tsukuba, Japan
  
  Transverse beam profiles have been measured using flying wire monitors at the main ring of the Japan Proton Accelerator Research Complex. The wire target should be thin and the wire scan has to be fast for the precise profile measurement. Otherwise the beam distribution would be disturbed and the measured profile would not be accurate. We use carbon fibers of 7 μm in diameter and the scan speed of 10 m/s. The wire is attached with an aluminum flame of 140 mm of the rotation radius and rotated with a DC servomotor. A potentiometer is attached to the wire flame and the angle readout is used for the feedback of the servomotor and the wire position measurement. The secondary particles from the beam-wire scattering are measured with a scintillation counter. Beam profiles are reconstructed by making the scatter plot of the scintillator signal and wire position. Both horizontal and vertical flying wire monitors have been used for the beam commissioning. We have successfully measured the beam profile of up to 1.2×1013 protons per bunch.  
 
TUPB79 Use of Gafchromic Films to Measure the Transverse Intensity Distribution of a Large-area Ion Beam 1
 
  • Y. Yuri, I. Ishibori, T. Ishizaka, A. Kitamura, S. Okumura, T. Yuyama
    JAEA/TARRI, Gunma-ken, Japan
  • S. Sawada, T. Yamaki
    JAEA/QuBS, Takasaki, Japan
  
  In the TIARA AVF cyclotron facility of JAEA, it is necessary to evaluate the cross-sectional area and uniformity of a large-area uniform ion beam formed by multipole magnets both precisely and handily. A technique has, therefore, been developed to measure the two-dimensional transverse intensity distribution of the ion beam using Gafchromic radiochromic films (Ashland Inc.). In order to show available fluence ranges of the film, the coloring response of the Gafchromic films irradiated with several species of ion beams is investigated as a change in the optical density of the film. It has been found that the optical density increases linearly with the fluence, whose range is practical for materials and biological research. Thus, the relative transverse intensity distribution of ion beams can be measured using the film. Furthermore, the intensity distribution determined by the Gafchromic film is compared with the area-density distribution of track-etched pores in a polymer film from a microscopic viewpoint. It has been demonstrated that the beam uniformity obtained from the Gafchromic film is equivalent to the relative standard deviation of the microscopic pore distribution.  
 
TUPB80
 Transverse Profile Monitor for SwissFEL  
 
  • R. Ischebeck, B. Beutner, E. Prat, V. Schlott, V.G. Thominet
    PSI, Villigen, Switzerland
  
  In future free electron lasers, electron and photon beam sizes range between 10 um and a few millimeters. For an initial set up of the accelerator, to confirm target parameters for optics and emittance, and to optimize the FEL for different user requests, the transverse profile of these beams has to be determined. A monitor based on a scintillating crystal as well as optical transition radiation (for the electron beam) has been designed for the SwissFEL project. It features a projected pixel size of 7 micrometers, a good resolution over a field of view of 6 mm x 15 mm, a good sensitivity (as required for the low-charge mode of SwissFEL) and a 100 Hz image readout. To test the monitor, it has been installed at the SwissFEL Injector Test Facility, where electron bunches between 10 and 200 pC can be generated. In conjunction with a transverse deflecting cavity, the profile monitor has been used to measure the time-resolved slice emittance of these bunches.  
 
TUPB81 Design of the Beam Profile Monitors for the SXFEL Facility 1
 
  • L.Y. Yu, J. Chen, Y.B. Leng, K.R. Ye, W.M. Zhou
    SINAP, Shanghai, People's Republic of China
  
  The Shanghai X-ray Free Electron Laser Facility will begin construction at next year. The linac electron beam energy is 0.84 GeV. Over 50 beam profile monitors with OTR and YaG screen will be installed along the linac and undulators. The profile monitor system design is a challenging task, since the system has to measure transverse electron beam sizes from millimeter down to 40μm scale with a 20μm resolution and 50μm repeat positioning accuracy. This paper describes the design of the mechanical detector , the integrated step-servo motor controlling system, the beam imaging system, as well as the software system.  
 
TUPB82
 Development of Laser Wire System in the Electron Beam Transport Line of BEPCⅡ  
 
  • C. Zhang, J. Cao, Q.Y. Deng, Y.F. Sui
    IHEP, People's Republic of China
  
  Funding: National Natural Science Foundation of China
A Laser Wire system is under development in the electron beam transport line of BEPCⅡ (Beijing Electron Positron Collider Ⅱ). The whole system will be installed in the tunnel of beam transport line in this summer shutdown of the BEPCII. We present recent work on subsystems of Laser Wire in this paper, such as improvement of laser system and construction of gamma detector. Some measurement and test results are also showed. The electron beam profile measurement experiment with Laser Wire will start in the next accelerator run. 		 
 
WECA01
 Theoretical and Experimental Investigation on Resolution of Optical Transition Radiation Transverse Beam Profile Monitor  
 
  • A.S. Aryshev, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  • B. Bolzon, E. Bravin, T. Lefèvre
    CERN, Geneva, Switzerland
  • S.T. Boogert, V. Karataev
    Royal Holloway, University of London, Surrey, United Kingdom
  • L.J. Nevay
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  
  Optical Transition Radiation (OTR) appearing when a charged particle crosses an interface between two media with different dielectric constants has widely been used as a tool for transverse profile measurements of charged particle beams in numerous facilities worldwide. The basic tuning methods and operation of conventional OTR monitors are well established for transverse beam sizes not smaller than 3-5 um. Since the Point Spread Function (PSF) dimension defines the resolution of the conventional monitors, for small electron beam dimensions the PSF form significantly depends on a presence of OTR tails diffraction and aberrations in the optical system. In our experiment we have managed to squeeze the electron beam such that we can practically measure PSF distribution in one direction. The revealed PSF structure is such that the visibility depends on the transverse beam size on micron scale. We developed an empirical calibration technique and successfully overcame the resolution limit of the common OTR monitor reaching sub-micron level. Here we represent the recent developments and upgrades in both setup and data analysis of a sub-micrometer electron beam profile monitor.  
 
WECC03 Intensity Imbalance Optical Interferometer Beam Size Monitor 1
 
  • M.J. Boland
    ASCo, Clayton, Victoria, Australia
  • T.M. Mitsuhashi, T. Naito
    KEK, Ibaraki, Japan
  • K.P. Wootton
    The University of Melbourne, Melbourne, Australia
  
  The technique of measuring the beam size in a particle accelerator with an optical interferometer with the Mitsuhashi apparatus is well established and one of the only direct measurement techniques available. However, one of the limitations of the technique is the dynamic range and noise level of CCD cameras when measuring ultra low emittance beams and hence visibilities close to unity. A new design has been successfully tested to overcome these limitations by introducing a know intensity imbalance in one of the light paths of the interferometer. This modification reduces the visibility in a controlled way and lifts the measured interference pattern out of the noise level of the CCD, thus increasing the dynamic range of the apparatus. Results are presented from tests at the ATF2 at KEK and on the optical diagnostic beamline at the Australian Synchrotron storage ring.  
 
WEIC02
 Recent Progresses in SR Interferometer  
 
  • T.M. Mitsuhashi
    KEK, Ibaraki, Japan
  
  Beam size measurement in accelerator is very important to evaluate beam emittance.　SR interferometer has been used as one of powerful tools for measurement of small beam size through special coherence of visible SR. Recent progresses in this technique improve measurable range for smaller beam size less than 10μm. An application of reflective optics to eliminate chromatic aberration in focus system of SR interferometer makes it possible to measure the beam size down to 5μm range. The unbalanced input technique is developed in recent few years, and this technique magnifies beam size 2-3 times, and observation range is improved down to 2-3μm range. These progresses on SR interferometer will introduce in this talk.  
slides icon Slides WEIC02 [1.687 MB]  
 
THCB02 Twisting Wire Scanner 1
 
  • V. Gharibyan, A. Delfs, I. Krouptchenkov, D. Nölle, H. Tiessen, M. Werner, K. Wittenburg
    DESY, Hamburg, Germany
  
  A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors will be presented.