MOPB —  Poster Session 1   (14-Sep-15   16:00—18:00)
Paper Title Page
MOPB001 Development of a Beam Pulse Monitor for the Heavy Ion Accelerator Facility 1
  • D. Tsifakis, P. Linardakis, N.R. Lobanov
    Research School of Physics and Engineering, Australian National University, Canberra, Australian Capitol Territory, Australia
  The ANU Heavy Ion Accelerator Facility (HIAF) comprises a 15 MV electrostatic accelerator (NEC 14UD) followed by a superconducting LINAC booster. The pulsing system consists of a low energy single gap gridded buncher and two high energy choppers. Buncher and choppers need to be set in phase and amplitude for maximum efficiency. The LINAC encompasses twelve lead tin-plated Split Loop Resonators (SLR). Each SLR, as well as the superbuncher and time energy lens, needs to be individually tuned in phase and amplitude for correct operation. The HIAF pulsing system is based on a few techniques. The first one utilises a U-bend at the end of the LINAC. One special wide Beam Profile Monitor (BPM) is installed after the 90 degrees magnet. The technique allows to set up correct phase by observing the displacement of beam profile versus phase shift of the last phase locked resonator. The determination of beam pulse characteristics are based on X-ray detection produced by beam striking a Ta target. In this paper the HIAF set up for pulsed beam diagnostics with sub nanosecond time resolution is described. The system has demonstrated simplicity of operation and high reliability.  
poster icon Poster MOPB001 [3.526 MB]  
A Compact Weather Station for Monitoring Environmental Effects on Beam Properties and Equipment  
  • S. Cunningham, R. Clarken, A. C. Starritt
    ASCo, Clayton, Victoria, Australia
  • A. C. Starritt
    SLSA, Clayton, Australia
  A compact and mobile weather station has been designed and integrated with EPICS to assist with environmental monitoring at the Australian Synchrotron. This proved invaluable in correlating the dependence of the Storage Ring RF phase with humidity. The device is based on Arduino technology and consists entirely of substitutable parts allowing for easy repair and maintenance by people of any degree of technical skill. The project aim is to deploy several of these devices throughout the facility to enhance the understanding of environmental effects on beam properties and equipment.  
poster icon Poster MOPB002 [0.602 MB]  
Development of RF Peak Detector and Phase Monitoring Unit at the Australian Synchrotron.  
  • A. Michalczyk
    ASCo, Clayton, Victoria, Australia
  • N.J. Basten, R.T. Dowd, G. LeBlanc, R. LeGuen, A. C. Starritt, K. Zingre
    SLSA, Clayton, Australia
  An RF peak detector and phase monitoring unit was developed as a part of the LINAC and Booster RF diagnostic system at the Australian Synchrotron (AS). The system captures a maximum of 16-pulsed or continuous RF signals to measure forward and reverse power levels. This unit has also I/Q demodulator, which provides phase information to assist with tuning and allows to diagnose instabilities. The design and development of this system will be presented in this poster. This novel 'in-house' designed LINAC and Booster RF Peak Detector and Phase Monitoring unit has been operating successfully since May 2012. The compact system provides excellent performance, EMC and thermal stability using only convectional cooling. The system has already proven to be a great diagnostic tool for trouble-shooting.  
poster icon Poster MOPB004 [1.069 MB]  
A Single-Shot High-Repetition Rate Electro-Optic Detection of Short Pulses Using the Photonic Time-Stretch Strategy  
  • E. Roussel, S. Bielawski
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  • J.B. Brubach, L. Cassinari, M.-E. Couprie, M. Labat, L. Manceron, J.P. Ricaud, P. Roy, M.-A. Tordeux
    SOLEIL, Gif-sur-Yvette, France
  • C. Evain, C. Szwaj
    PhLAM/CERLA, Villeneuve d'Ascq, France
  • M. Le Parquier
    CERLA, Villeneuve d'Ascq, France
  In accelerator-based light sources, there is a growing need for high repetition rate, single-shot, characterization of electron bunch shapes and THz pulses. At moderate repetition rate, an efficient strategy consists in encoding the ultrafast information onto a laser pulse, which is subsequently analysed (electro-optic sampling). However, these methods usually require cameras as the final detector, which represents a bottleneck in the quest for high-repetition rates. A promising candidate for breaking this « high repetition rate barrier » is the so-called photonic time-stretch technique. In this presentation, we present the first results obtained with time-stretch in the accelerator context: Electro-optic sampling of successive terahertz bursts of coherent synchrotron radiation at SOLEIL*, with 88 MHz acquisition rates (and picosecond resolution). In practice, the time-stretch is potentially realizable as a relatively simple upgrade of existing setups (provided it is possible to imprint the ultrafast signal on chirped laser pulses). Finally we also present a performance analysis, including a comparative study of standard and time-stretched electro-optic sampling setups.
* "Observing microscopic structures of a relativistic object using a time-stretch strategy," E. Roussel et al., Scientific Reports 5, 10330 (2015).
poster icon Poster MOPB005 [3.282 MB]  
Electro-Optical Measurements of the Longitudinal Bunch Profile in the Near-Field on a Turn-by-Turn Basis at the Anka Storage Ring  
  • E. Roussel, S. Bielawski
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  • A. Borysenko, N. Hiller, A.-S. Müller, P. Schönfeldt, J.L. Steinmann
    KIT, Karlsruhe, Germany
  • C. Evain, C. Szwaj
    PhLAM/CERLA, Villeneuve d'Ascq, France
  Funding: This work is partially funded by the German Federal Ministry of Education and Research (BMBF) under contract numbers: 05K10VKC, 05K13VKA.
ANKA is the first storage ring worldwide with a near-field single-shot electro-optical bunch profile monitor. Previously, the method of electro-optical spectral decoding (EOSD) was employed to record single-shot longitudinal bunch profiles. The readout rate of the required spectrometer detector system limited the acquisition rate to a few Hz and thus did not allow us to study the evolution of the longitudinal bunch shape on a turn-by-turn basis. The setup at ANKA was combined with the novel method of photonic time-stretch* for which the modulated laser pulse is not detected in the spectral domain, but stretched to a few nanoseconds by a long fiber and, subsequently, detected in the time domain. This method allows the sampling of the longitudinal bunch profile on a turn-by-turn basis for several milliseconds, uninterrupted. Here, we present first results obtained with the photonic time-stretch method in the near-field at the ANKA storage ring.
* "Observing microscopic structures of a relativistic object using a
time-stretch strategy," E. Roussel et al, Scientific Reports 5, 10330
MOPB007 SRF Gun Beam Characterization - Phase Space and Dark Current Measurements at ELBE 1
  • E. Panofski, A. Jankowiak, T. Kamps
    HZB, Berlin, Germany
  • P.N. Lu, J. Teichert
    HZDR, Dresden, Germany
  RF photoelectron sources with superconducting cavities provide the potential to generate high quality, high brightness electron beams for future accelerator applications. At Helmholtz-Zentrum Dresden Rossendorf, such an electron source was operated for many years. The commissioning of an improved SRF Gun with a new high-performance gun cavity with low field emission and a superconducting solenoid inside the gun cryomodule (SRF Gun II) has started in June 2014. Simulations of the experimental set-up with ASTRA and ELEGANT were performed. First low current measurements as well as studies of unwanted beam transport using SRF Gun II with Cu photocathode and an acceleration gradient up to 9 MV/m will be presented. First beam characterization of the SRF Gun in combination with ELBE, a two-stage superconducting linear accelerator will be discussed.  
poster icon Poster MOPB007 [1.258 MB]  
MOPB009 Jitter Analysis at CW Repetition Rate With Large Spectral Range and High Resolution. 1
  • M. Kuntzsch, M. Gensch, U. Lehnert, P. Michel, R. Schurig, J. Teichert
    HZDR, Dresden, Germany
  At the superconducting CW accelerator ELBE electron bunch diagnostics has been installed recently, enabling the investigation of bunch arrival-time jitter and electron energy fluctuations for varying bunch compression states. Using these diagnostic systems, a comprehensive investigation has been performed that reveals the influence of the bunch compression to spectral noise components up to a frequency of 100 kHz (i.e. 200 kHz bunch repetition rate). The transformation of arrival-time jitter into energy jitter and vice versa can be observed. The perfomances of a DC thermionic and a SRF photoinjector at the CW- SRF Linac ELBE are compared and an interpretation for different noise components is presented.  
Trigger Generator for the Superconducting Linear Accelerator ELBE  
  • R. Steinbrück, M. Justus, M. Kuntzsch
    HZDR, Dresden, Germany
  • T. Bergmann
    BME, Murnau, Germany
  • A. Kessler
    HIJ, Jena, Germany
  Funding: none
The Center for High-Power Radiation Sources ELBE at HZDR in Germany runs a superconducting linear electron accelerator for research applications. A recent machine upgrade enabled new time resolved experiments and made a replacement of the current trigger system necessary. The requirements focused on centralisation, trigger quality, and versatile trigger pattern generation. To address these needs digital delay generators developed by Bergmann Messgeräte Entwicklung have been evaluated. Each of the FPGA-based PCI boards has 6 independent trigger channels with a resolution of 25 ps. PCI modules can be connected by a dedicated trigger bus to ensure extensibility. The boards are installed in an industrial Windows 7 PC. Trigger generation runs stand-alone in an FPGA making it independent of operating system timing and ensuring stable phase relation between individual channels. FPGA control is possible via C and LabVIEW APIs. The ELBE control system is built with Siemens PLCs and WinCC HMI. A LabVIEW application will offer a GUI for local and remote control via OPC. The contribution will show the layout of the trigger generation system and the status of software development activities.
MOPB012 Vector Polarimeter for Photons in keV-MeV Energy Range 1
  • V. Gharibyan, K. Flöttmann, G. Kube, K. Wittenburg
    DESY, Hamburg, Germany
  Light's linear and circular polarizations are analyzed simultaneously by vector polarimeters mainly in astrophysics. At higher energies Compton scattering or absorption is applied for linear or circular polarization measurements in satellites and accelerators. Here we propose a Compton scattering only vector polarimeter for monitoring photon beams in a non-invasive way. The setup is adjustable to match the initial photons' energy and can be used for diagnosing electrons' passage through undulators. In perspective the proposed device could also be explored to measure topological charge of the novel vortex photon beams.  
MOPB013 Cryogenic Current Comparator for Storage Rings and Accelerators 1
  • R. Geithner, T. Stöhlker
    IOQ, Jena, Germany
  • M.F. Fernandes
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • M.F. Fernandes
    CERN, Geneva, Switzerland
  • M.F. Fernandes
    The University of Liverpool, Liverpool, United Kingdom
  • R. Geithner, T. Stöhlker
    HIJ, Jena, Germany
  • F. Kurian, H. Reeg, M. Schwickert, T. Sieber, T. Stöhlker
    GSI, Darmstadt, Germany
  • R. Neubert, P. Seidel
    FSU Jena, Jena, Germany
  A Cryogenic Current Comparator (CCC) was developed for a non-destructive, highly sensitive monitoring of nA beams at the planned FAIR accelerator facility at GSI. The sensor part of the CCC was optimized for lowest possible noise-limited current resolution in combination with a high system bandwidth of about 200 kHz. It is foreseen to install the CCC inside the CRYRING, which will act as a well-suited test bench for further optimization of the CCC performance and the cryostat. In the meantime - until the completion of CRYRING - a CCC has been installed and will be tested in the antiproton storage ring (Antiproton Decelerator AD) at CERN. The pulse shape in the AD requires dedicated optimization of the sensor time response. The beam current will increase rapidly during injection from 0 to 12 μA. Since the slew rate of the overall system is limited by the CCC pickup coil, the input signal has to be low-pass filtered to not exceed the slew rate of the CCC system and to ensure a stable operation. For this purpose different low-pass configurations had been tested. In this contribution we present results of the CCC ¬sensor for AD, CRYRING and FAIR, respectively.  
poster icon Poster MOPB013 [4.700 MB]  
Beam Diagnostics for the High Energy Storage Ring at FAIR  
  • C. Böhme, A.J. Halama, V. Kamerdzhiev, F. Klehr, D. Prasuhn, K. Reimers, S. Srinivasan, D. Temme, R. Tölle
    FZJ, Jülich, Germany
  Numerous beam diagnostics systems, with the BPM system considered the most important one, are envisaged for the High Energy Storage Ring (HESR) within the FAIR Project. The BPM design, the corresponding test bench, HESR BLM studies at COSY, status of the ionization profile monitor and other subsystems are presented.  
MOPB015 A Patient-Specific QA Procedure for Moving Target Irradiation in Scanned Ion Therapy 1
  • Y. Hara, T. Furukawa, K. Mizushima, K. Noda, N. S. Saotome, Y. Saraya, T. Shirai, R. Tansho
    NIRS, Chiba-shi, Japan
  Three-dimensional (3D) pencil-beam scanning technique has been utilised since 2011 in NIRS-HIMAC. The beam delivery system and treatment planning software (TPS) require dosimetric patient-specific QA to check each individual plan. Any change in the scanned beams will result in a significant impact on the irradiation dose. Therefore, patient-specific QA for moving target irradiation requires additional procedure. In an additional QA for moving target irradiation, we placed a 2D ionization chamber on the PMMA plate tilted with respect to the beam axis. The PMMA plate was set on the stage of the moving phantom. The moving phantom was moved according to patient data. We measured the dose distribution for both the static target and the moving target. We compared the results for the moving target with those for the static targets by means of a gamma index analysis. In the additional patient-specific QA, the gamma analysis between the moving and static targets showed a good agreement. We confirmed that this new technique was a beneficial QA procedure for moving target irradiation.  
poster icon Poster MOPB015 [1.571 MB]  
MOPB016 Development of QA System for the Rotating Gantry for Carbon Ion Therapy at NIRS 1
  • N. S. Saotome, T. Furukawa, Y. Hara, K. Mizushima, K. Noda, Y. Saraya, T. Shirai, R. Tansho
    NIRS, Chiba-shi, Japan
  At the National Institute of Radiological Sciences (NIRS), we have been developing the rotating-gantry system for carbon-ion radiotherapy. This system is equipped with a three-dimensional pencil beam scanning irradiation system. To ensure the treatment quality, calibration of the primary dose monitor, range check, dose rate check, machine safety check, and some mechanical tests should be performed efficiently. For this purpose, we have developed a measurement system dedicated for quality assurance (QA) of this gantry system. The ion beam's dose output was calibrated by measurement using an ionization chamber. A Farmer type ionization chamber was inserted into the center of a plastic water phantom. The thickness of the phantom could be changed so that it employs both calibration of the output at entrance and output checking at center of the irradiation field. The ranges of beams are verified using a CCD camera and a scintillator system. From the taken images, maximum gradient points are determined by some image processing and compared with reference data. In this paper, we describe consideration of the daily QA for the rotating-gantry.  
MOPB017 Development of FPBA-Based TDC With Wide Dynamic Range for Monitoring the Trigger Timing Distribution System at the KEKB Injector Linac 1
  • T. Suwada, K. Furukawa, F. Miyahara
    KEK, Ibaraki, Japan
  A new field-programmable gate array (FPGA)-based time-to-digital converter (TDC) with a wide dynamic range greater than 20 ms has been developed to monitor the timing of various pulsed devices in the trigger timing distribution system of the KEKB injector linac. The pulsed devices are driven by feeding regular as well as any irregular (or event-based) timing pulses. For monitoring the timing as precisely as possible, a 16-ch FPGA-based TDC has been developed on a Xilinx Spartan-6 FPGA equipped on VME board with a time resolution of 1 ns. The resolution was achieved by applying a multisampling technique, and the accuracies were 2.6 ns (rms) and less than 1 ns (rms) within the dynamic ranges of 20 ms and 7.5 ms, respectively. The various nonlinear effects were improved by implementing a high-precision external clock with a built-in temperature-compensated crystal oscillator.  
poster icon Poster MOPB017 [3.161 MB]  
MOPB018 Data Acquisition System for SuperKEKB Beam Loss Monitors 1
  • M. Tobiyama, J.W. Flanagan, H. Ikeda
    KEK, Ibaraki, Japan
  The monitoring of the beam loss distribution along the accelerator is important in order to prevent damage of the vacuum components, and, in addition, to suppress the unnecessary irradiation of the accelerator elements. As it is not easy to construct the readout system to be synchronised to a fast timing signal, such as beam injection, a new 64-ch ADC system has been developed that samples the output of the loss monitor signal integrator with a fairly fast rate and automatically keeps the peak, mean and minimum of the data. The performance of the ADC system will be shown. The control system configuration that reads and resets the hardware interlock signal from the loss monitor signal integrator for the machine protection system (MPS) will also be presented.  
poster icon Poster MOPB018 [0.297 MB]  
Residual Radiation Measurements by Beam Loss Monitors at J-PARC Main Ring  
  • T. Toyama, K. Satou
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • H. Kuboki, M.J. Shirakata, B. Yee-Rendón
    KEK, Tokai, Ibaraki, Japan
  In J-PARC (the Japan Proton Accelerator Research Complex), a high intensity proton accelerator, controlling and localising beam losses and residual radiations are a key issue, because the residual radiation limits maintenance work in efficiency, working hours, and machine availability. To step forward we began continuous measurement of residual radiation after beam shutdown using beam loss monitors in the Main Ring (MR). Wire cylinder gaseous radiation detectors are used in a proportional counting region. The heads are DC-connected and have a gain as large as 30000 with a bias of 2 kV. We change the DAQ trigger and the gain as soon as the accelerator operation ends. The offsets are measured with a zero bias voltage. We could identify some radionuclides from the time evolution of the dose by performing a comparison to simulation. Accumulation of long lived radionuclides and future workability are expected from this data.  
MOPB021 Signal Response of the Beam Loss Monitor as a Function of the Lost Beam Energy 1
  • K. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  The J-PARC 3 GeV rapid cycling synchrotron (RCS) accelerates a proton beam up to 3GeV and delivers it to the main ring and the Material and Life Science Experimental Facility. The injection energy of the RCS was 181 MeV since 2013, and it was upgraded to 400 MeV in 2014. Main magnets (dipole and quadrupole magnets) of the RCS have large aperture, and thickness of yoke is larger than 200 mm. Considering the stopping power of a proton, the shielding effect of the magnets strongly depends on the lost beam energy. When the beam loss occurs during injection, the lost proton cannot penetrate the magnet yoke. But when the beam loss occurs after acceleration, the lost beam easily passes the magnet. Therefore the signal response of the beam loss monitor is changed even if the loss power is the same. To evaluate the amount of the lost particles from BLM response, we estimated the signal dependence on the lost energy from simulation.  
MOPB022 Diagnostics During SESAME Booster Commissioning 1
  • H. Al-Mohammad, K. Manukyan
    SESAME, Allan, Jordan
  SESAME* is a 2.5 GeV synchrotron radiation facility under construction at Allan (Jordan), consisting of a 20 MeV Microtron as pre-injector and an 800 MeV Booster Synchrotron. The pre-injector and booster are originally BESSY-I machine with some major changes within power supplies and diagnostics tools. The diagnostic tools are: Fluorescent Screens, BPMs, DCCT, FCT and Synchrotron Radiation Monitor. The Booster had been commissioned in 2014. The installed tools allowed to determine current, orbit, tune, chromaticity and emittance. Set up of the diagnostics and results are presented in this paper.
poster icon Poster MOPB022 [1.564 MB]  
MOPB023 A Comparative Study Between Simulated and Measured Beam's Quality of 30 MeV Cyclotron at KFSHRC 1
  • F.M. Alrumayan, A. Alghaith, A. Hendy
    King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Kingdom of Saudi Arabia
  • M.P. Dehnel
    D-Pace, Nelson, British Columbia, Canada
  Funding: This project was supported by NSTIP strategic technologies program in the Kingdome of Saudi Arabia-Award No (14-MAT1233-20).
At King Faisal Specialist Hospital and Research Centre (KFSHRC), the C-30 Cyclotron (manufactured by IBA) is used to produce radioisotopes for medical purposes. Working with very expensive machine dedicated for patients needs full attention and understanding of how beam can be controlled safely inside beam transport system. Moreover, knowledge of influence of magnetic lenses on charged particles is desired. Therefore, using off-line source such as PC-based beam simulator allows an operator to immediately see the effect of various magnetic lenses attached to the beam line. This would eliminate any damage may take place from striking of beam on the internal wall of beamline. For real beam measurement, beam position and profile was studied using a beam viewer. Whereas, simulated beam was generated using Beam Simulator program. Initially, the magnetic field of quadruples and steering magnet was recorded using Hall probe Teslameter. The magnetic field values were measured and then uploaded into the Beam simulator in which beam shape and position were recorded.
MOPB025 Heating Analysis and the Solutions of Dcct System for Bepcii 1
  • Y. Zhao, J.S. Cao, J. He, Y.F. Sui, L. Wang
    IHEP, Beijing, People's Republic of China
  The BEPCII e+ DCCT is damaged due to a high temperature heating. After 8 years operating, it is not working properly in 2014. As the BEPCII is trying to reach high luminosity, the CT will be a defective component with the high beam current, therefore a spare one has replaced it. In order to determine the heating source, some experiments and simulations have been done. A new vacuum chamber structure has been designed to solve the problem. The analysis and result can be also applied to CT designs in the future.  
MOPB026 Phase and Energy Measurement System for C-ADS Injector I 1
  • J.H. Yue, Q.Y. Deng, J. Hu, S.J. Wei, Q. Ye
    IHEP, People's Republic of China
  For proton linac, phase and energy measurement is very important. Beam phase always can be measured by quadrature sampling, energy can be measured by the method of time of flight (TOF), in this way we need to know the beam phase of two points whose distance is given. C-ADS injector I is a 10MeV proton linac with 10mA continuous current. It consists of an ECR (Electron Cyclotron Resonance) ion source, a LEBT (Low Energy Beam Transport), a 3MeV RFQ (Radio-frequency Quadruple) and a superconductivity linac accelerator with 3~10MeV. In the initial phase, the beam energy is about 3MeV. In this paper, phase and beam energy system of C-ADS Injector I have been introduced and some preliminary results have been shown.  
Beam Instrumentation and Commissioning of C-ADS Injector II  
  • J.X. Wu
    IMP/CAS, Lanzhou, People's Republic of China
  An accelerator-driven subcritical system (ADS) project has been launched in China in 2011, which aims to design and build an ADS demonstration facility with the capability of more than 1000 MW thermal power in multiple phases lasting about 20 years. The driver LINAC has two injectors in parallel to provide up to 10 mA cw proton beam with the energy of 10 MeV. The injector II is constructed by IMP and its beam commissioning was started since 2013 with the 560 keV RFQ prototype. In 2014, more than 10 mA cw beam after RFQ with the energy of 2.1 MeV was successfully commissioned. In 2015 it aims at providing 5 MeV cw beam after the first CM. This paper will introduce the beam instrumentation on the C-ADS injector II. Also the beam commissioning and the challenges encountered will be described as well.  
MOPB030 Time Measurement Method Based on CPLD for Beam Loss Position Monitor 1
  • Y. Yang, Y.B. Leng, Y.B. Yan
    SSRF, Shanghai, People's Republic of China
  Beam loss position is of great concern at SSRF. Time measurement is one of the key technologies for beam loss position monitor. This paper introduces a time measurement method based on Complex Programmable Logic Device (CPLD). Simulation has been done to verify the performance of this method.  
MOPB031 Electron Beam Uniformity Detection Device for Irradiation Accelerators 1
  • L.G. Zhang, J. Huang, K.F. Liu, J. Yang, C. Zuo
    HUST, Wuhan, People's Republic of China
  High-voltage electron accelerators are widely used in the irradiation processing industry. Beam uniformity of the accelerator has a very important impact on the quality of irradiated products. Accurate measurement of beam uniformity helps to improve product quality and production efficiency. In this paper, the electron beam uniformity detection device is designed based on a Faraday cup array followed by the signal shaping circuit and the digital signal processing system. Finally, the computer offers a friendly interface to help users understand the operating state of the accelerator and the electron beam uniformity information. This device uses DSP technology to process the signal and optical fibre to communicate which greatly improves the noise immunity capability of the system. Through such a high precision and easy to use detection device, a user can get the accelerator beam irradiation uniformity information which is very useful for guiding the industry radiation process.  
poster icon Poster MOPB031 [0.971 MB]  
MOPB032 Design and Analysis of a Beam Uniformity Detector Based on Faraday Cup Array 1
  • C. Zuo, J. Huang, J. Yang, L.G. Zhang
    HUST, Wuhan, People's Republic of China
  Beam uniformity of electron irradiation accelerator has a great impact results for industrial radiation process. In this paper, a beam uniformity detector, based on Faraday cup array, has been designed for a 400 kV electron irradiation accelerator in Huazhong University of Science and Technology. Suitable structure has been calculated for the secondary electrons emission. Cooling system is necessary for the detector in the condition of high-intensity ion beams, and it has been designed by thermo-structural analysis. This detector now has been used for experiments successfully.  
poster icon Poster MOPB032 [11.080 MB]  
MOPB034 CW Laser Based Phase Reference Distribution for Particle Accelerators 1
  • S. Jabłoński
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  • H. Schlarb, C. Sydlo
    DESY, Hamburg, Germany
  We present a cost-effective solution for the synchronization of RF signal sources separated by tens of kilometers with the femtosecond accuracy. For the synchronization a phase reference distribution system (PRDS) is developed, which is comprised of a CW optical transmitter connected via single mode fiber-optic links to remote receivers. This technique enables to use only one transmitter for multiple receivers and removes the necessity of active stabilization units (e.g. piezo-driven fiber stretchers or laser wavelength tuning), which reduces considerably the system cost. The concept of the new RF reference distribution, parameters of crucial components, phase drift detection and correction techniques are introduced, which lead to low noise and long-term stable PRDS operation. Detrimental effects of various linear and nonlinear fiber impairments are discussed. One of the most important elements is the phase detector, which is based on a direct RF-sampling ADC and it features a femtosecond measurement precision over 2pi phase change. Finally, the long-term performance of the designed PRDS is shown, which was evaluated with a 500-m single-mode fiber and an RF signal of 1.3 GHz.  
MOPB035 Beam Profile Measurements with a Slit-Faraday Cup and a Wire Scanner for a Newly Developed 18 Ghz Superconducting ECR Ion Source and its LEBT 1
  • H.J. You, W.I. Choo, S.O. Jang
    NFRI, Daejon, Republic of Korea
  In this presentation we show results of beam profile measurements by a slit-Faraday cup system and a wire scanner. Argon 8+ beams were generated in a new liquid helium-free superconducting electron cyclotron resonance ion source (ECRIS)*, The ECRIS, named SMASHI, was successfully developed at the National Fusion Research Institute in 2014**, and in the future it will be dedicated for highly charged ions matter interaction research facility (HIMIRF). Before designing and constructing HIMIRF terminals after low energy beam transport(LEBT), it is necessary to characterize the beam properties of the source and its LEBT line. The beam profile measurements have been done after an analyzing dipole magnet(DM). The slit-Faraday cup and the wire scanner were installed at 25 cm and 120 cm from the exit flange of AM, respectively. Between the two diagnostics an Einzel lens was positioned to control the focusing of diverged beams. Here, with the measurements we checked the present beam alignments in the LEBT, and studied the dependence of beam profile variation on the operations of beam optics such as steering magnets and Einzel lens..
* H. J. You and K. M. Park, J. Supercond. Nov. Mag. 28, 651 (2015).
** H. J. You, S. O. Jang, and W. I. Choo, Rev. Sci. Instrum. 85, 02A916 (2014).
poster icon Poster MOPB035 [0.866 MB]  
MOPB036 PAL-XFEL's Turbo-ICT for Beam Charge Monitoring 1
  • H. J. Choi, J.H. Han, J.H. Hong, H.-S. Kang, S.H. Kim, B.R. Park, S.J. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
  The construction of PAL-XFEL building, which is a fourth-generation synchrotron radiation-light source, was completed in February 2015. Concentration accelerating devices (Accelerator tube, Klystron, Modulator) and undulators will be installed by December of 2015 and commissioning concentration devices will be completed by the start of 2016. A Beamline user service will be started from the middle of 2016. The installation of PAL-ITF (Injector Test Facility) was completed at the end of 2012 for the production of high-quality electron bunch, and efforts were made to improve the performance of the pre-injector system and diagnostic equipment. In this study, details of the performance improvements at PAL-ITF measured by a Bergoz Turbo-ICT, which is able to measure the amount of electric charge from 0.1 to 200pC, and the operating plan for the Turbo-ICT which will be installed and operated in PAL-XFEL are introduced.  
MOPB037 Development of High Precision Capacitive Beam Phase Probe for KHIMA Project 1
  • J.G. Hwang, S.Y. Noh
    KIRAMS/KHIMA, Seoul, Republic of Korea
  • P. Forck
    GSI, Darmstadt, Germany
  • T.K. Yang
    KIRAMS, Seoul, Republic of Korea
  In the medium energy beam transport (MEBT) line of KHIMA project, a high precision beam phase probe monitor is required for a precise tuning of RF phase and amplitude of RFQ and IH-DTL. It is also used for measuring a kinetic energy of ion beam by time-of-flight (TOF) method using two phase probes. In this paper, we show the electromagnetic design of the high precision phase probe to satisfy the phase resolution of 1 deg (@ 200 MHz), the test result with a wire test bench to estimate a signal strength and phase accuracy, the design of the 0.2 ~ 2.0 GHz broad-band electronics for amplifying the signal strength, and the results of beam energy and RF frequency measurement using a proton beam from the cyclotron in KIRAMS.  
MOPB038 Status of Beam Diagnostics at KHIMA Facility 1
  • T.K. Yang, D.H. An, G. Hahn, H. Yim
    KIRAMS, Seoul, Republic of Korea
  • J.G. Hwang, C.H. Kim, S.Y. Noh, C.W. Park
    KIRAMS/KHIMA, Seoul, Republic of Korea
  The Korea Heavy Ion Medical Accelerator(KHIMA) is the cancer therapy facility based on a synchrotron which can accelerate carbon ion to 430 MeV/u and proton to 230 MeV/u. The facility has 4 sectors; LEBT(Low Energy Beam Transport) from ECRIS to RFQ+IH-DTL, MEBT(Medium Energy Beam Transport) from IH-DTL to synchrotron, synchrotron ring, HEBT(High Energy Beam Transport) from the ring to irradiation rooms, 3 treatment rooms and 1 research room. The conceptual design report for each part of the facility has been completed and manufacturing of some parts has been started. In the case of beam diagnostics at the KHIMA, 17 types of monitors are considered and installation of 93 devices in total is planned including the related instruments like slit and stopper, stripper and etc. This proceeding introduces specifications of each diagnostic devices and shows test results of some monitoring devices to be already manufactured.  
Beam Instrumentation for Protection of the ESS Linac  
  • T.J. Shea, C. Darve, M. Donna, H. Hassanzadegan, A. Jansson, M. Jarosz, I. Kittelmann, A. Nordt
    ESS, Lund, Sweden
  The European Spallation Source (ESS) linac will accelerate protons to 2 GeV in pulses 2.86 ms long with a peak current of 62.5 mA, ultimately producing a 5 MW beam. Because this beam presents a formidable threat to the superconducting cavities and other accelerator components, the impact of errant beam conditions has been evaluated with Monte Carlo simulations and thermo-mechanical analysis. These studies inform the requirements for the beam instrumentation systems tasked with protecting the accelerator. Throughout the linac, the beam current monitors will detect any significant beam loss or deviation from the intended beam current patterns. At the low energy end, neutron detectors will detect the loss of low energy protons while at the high energy end, ionisation chambers will do the same. Detection of errant conditions will result in the suppression beam production within tens of microseconds. This paper will review technical design choices that should minimise the probability of damage and activation while maximising machine availability. Anticipated technical challenges will also be discussed.  
MOPB040 Instrumentation in DESIREE 1
  • A. Källberg, M. Björkhage, M. Blom, H. Cederquist, G. Eklund, L. Liljeby, A. Paal, P. Reinhed, S. Rosén, H.T. Schmidt, S.B. Silverstein, A. Simonsson
    Stockholm University, Stockholm, Sweden
  • H. Danared
    ESS, Lund, Sweden
  • R.D. Thomas
    Stockholm University, Department of Physics, Stockholm, Sweden
  The use of the instrumentation in the cryogenic double electrostatic storage rings DESIREE is discussed. In particular measurements of the stored beam currents using either a fast kick-out of the beam or Schottky noise signals are presented. For the Schottky signals, both the area of the peak and the double-peak structure of the signal have been used. Also the first tests of a stochastic cooling system are described.  
poster icon Poster MOPB040 [1.382 MB]  
MOPB041 Study of the Transverse Beam Emittance of the Bern Medical Cyclotron 1
  • K.P. Nesteruk, M. Auger, S. Braccini, T.S. Carzaniga, A. Ereditato, P. Scampoli
    LHEP, Bern, Switzerland
  • P. Scampoli
    Naples University Federico II, Napoli, Italy
  The cyclotron laboratory for radioisotope production and multi-disciplinary research at the Bern University Hospital (Inselspital) features an IBA Cyclone 18 MeV proton cyclotron equipped with a Beam Transport Line (BTL), ending in a separate bunker. The horizontal and vertical transverse beam emittances were measured for the first time for this kind of accelerator. Two different techniques were used. A measurement based on quadrupole strength variation and beam width assessment after the last focusing section on the BTL was first performed. A second technique was developed employing 4 beam profilers located at successive positions around a beam waist. These novel beam profile detectors were developed by our group and are based on doped silica and optical fibers. For the data analysis, a statistical approach allowing for estimation of the RMS transverse emittance of a beam with an arbitrary density profile was applied. The results obtained with both methods were found to be in good agreement.  
poster icon Poster MOPB041 [1.628 MB]  
MOPB042 Beam Loss Monitors for the Cryogenic LHC Magnets 1
  • M.R. Bartosik, A. Alexopoulos, B. Dehning, M. Sapinski
    CERN, Geneva, Switzerland
  • V. Eremin, E. Verbitskaya
    IOFFE, St. Petersburg, Russia
  • E. Griesmayer
    CIVIDEC Instrumentation, Wien, Austria
  Funding: This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485.
The Beam Loss Monitoring system of the Large Hadron Collider close to the interaction points contains mostly gas ionization chambers working at room temperature, located far from the superconducting coils of the magnets. The system records particles lost from circulating proton beams, but is also sensitive to particles coming from the experimental collisions, which do not contribute significantly to the heat deposition in the superconducting coils. In the future, with beams of higher brightness resulting in higher luminosity, distinguishing between these interaction products and dangerous quench-provoking beam losses from the circulating beams will be difficult. It is proposed to optimise by locating beam loss monitors inside the cold mass of the magnets, housing the superconducting coils, in a superfluid helium environment, at 1.9 K. This contribution will present results of radiation hardness test of p+-n-n+ silicon detectors which, together with single crystal Chemical Vapour Deposition diamond, are the main candidates for these future cryogenic beam loss monitors.
MOPB043 A Cryogenic Current Comparator for the Low-Energy Antiproton Facilities at CERN 1
  • M.F. Fernandes, J. Tan
    CERN, Geneva, Switzerland
  • M.F. Fernandes, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • M.F. Fernandes, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • R. Geithner, T. Stöhlker
    IOQ, Jena, Germany
  • R. Geithner, T. Stöhlker
    HIJ, Jena, Germany
  • R. Neubert
    FSU Jena, Jena, Germany
  • M. Schwickert, T. Stöhlker
    GSI, Darmstadt, Germany
  Funding: Funded by the European Unions Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485.
Several laboratories have shown the potential of Cryogenic Current Comparators (CCC) for an absolute measurement of beam intensity down to the nA level. This type of current monitor relies on the use of Superconducting QUantum Interference Device (SQUID) magnetometers and superconductor magnetic shields. CERN, in collaboration with GSI Helmholtz Centre for Heavy Ion Research, Jena University, and the Helmholtz Institute Jena are currently developing an improved version of such a current monitor for the Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings. The primary goals are a better current measurement accuracy and overall enhanced system availability. This contribution presents the design of the CCC, an estimation of its resolution, dynamic limitations of the SQUID, as well as a description of the modifications to the coupling circuit and cryostat that were required to optimize the monitor for the anticipated beam parameters. First results from beam measurements are also presented. To our knowledge these are the first CCC beam current measurements performed in a synchrotron and the first to be performed with both coasting and bunched beams.
BLM Crosstalk Studies at the CLIC Two-Beam Module  
  • M. Kastriotou, S. Döbert, F.S. Domingues Sousa, E. Effinger, W. Farabolini, E.B. Holzer, E. Nebot Del Busto, W. Viganò
    CERN, Geneva, Switzerland
  • M. Kastriotou, E. Nebot Del Busto, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • M. Kastriotou, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  The Compact Linear Collider (CLIC) is a proposal for a future linear e+-e accelerator that can reach 3 TeV centre of mass energy. It is based on a two-beam acceleration scheme, with two accelerators operating in parallel. One of the main CLIC elements is a 2 m long two-beam module where power from a high intensity, low energy drive beam is extracted through Power Extraction and Transfer Structures (PETS) and transferred as RF power for the acceleration of the low intensity, high energy main beam. One of the main potential limitations for a Beam Loss Monitoring (BLM) system in a two-beam accelerator is so-called 'crosstalk', i.e. signals generated by losses in one beam, but detected by a monitor protecting the other beam. This contribution presents results from comprehensive studies into crosstalk that have been performed at a two-beam module at the CLIC Test Facility (CTF3) at CERN. The capability of estimating the origin of losses for different scenarios is also discussed.  
MOPB046 First K-Modulation Measurements in the LHC During Run 2 1
  • M. Kuhn, V. Kain, A. Langner, R. Tomás
    CERN, Geneva, Switzerland
  Several measurement techniques for optics functions have been developed for the LHC. This paper discusses the first results with a new k-modulation measurement tool. A fully automatic and online measurement system has been developed for the LHC. It takes constraints of various systems such as tune measurement precision and powering limits of the LHC superconducting circuits into account. K-modulation with sinusoidal excitation will also be possible. This paper presents the first k-modulation and β* measurement results in the LHC in 2015. In addition, the measured beta functions will be compared to results from the turn-by-turn phase advance method.  
poster icon Poster MOPB046 [0.555 MB]  
MOPB048 Design Concept for a THz Driven Streak Camera With Ultra High Resolution 1
  • M.M. Dehler, F. Frei, R. Ischebeck, V. Schlott
    PSI, Villigen PSI, Switzerland
  • J. Fabianska, T. Feurer, M. Hayati
    Universität Bern, Institute of Applied Physics, Bern, Switzerland
  The resolution of streak camera systems strongly depends on the slew rate of the deflecting element, being proportional to the amplitude and the frequency of the deflector. An attractive approach to reach femto and even sub-femtosecond resolution are THz driven electron streak cameras, which have been only recently proposed. Here, the ultra fast streaking field is generated by exciting a suitable resonant THz antenna, e.g. a split ring resonator with an intense THz pulse. With today's THz sources streak field amplitudes in excess of 1 GV/m are within reach. Here, we present the concept for a proof of principle system. The THz pulse will be generated by rectifying the pulse from an existing 800 nm laser system in a suitable crystal as LiNbO3. For the source of the electron beam to be streaked, we are exploring two options, first a DC driven photo gun with electron energies between 10 and 100 keV, and second an RF photo gun yielding a relativistic 6.5 MeV beam. We describe the setup of the system for both cases and present simulations of the beam dynamics.  
MOPB049 An Optical Intra-Bunch Instability Monitor for Short Electron Bunches 1
  • T.G. Lucas, P.J. Giansiracusa, D.J. Peake, R.P. Rassool
    The University of Melbourne, Melbourne, Victoria, Australia
  • M.J. Boland
    ASCo, Clayton, Victoria, Australia
  • R.J. Steinhagen
    GSI, Darmstadt, Germany
  An improved understanding of intra-bunch instabilities in synchrotron light source electron bunches is crucial to overcoming the imposed limitations of the achievable intensity. A Multiband Instability Monitor, designed specifically for the short bunches of a synchrotron light source, has been developed to perform measurements of intra-bunch dynamics. The MIM performs real-time measurements at a diagnostic beamline using optical synchrotron radiation incident on a high speed photodetector. Three frequency bands up to 12 GHz were used to identify characteristic frequency signatures of intra-bunch instabilities. Mixed to baseband using RF detectors, these high frequency measurements can be performed without the need for similarly high frequency digitisers. This paper reports on the performance of the system at the Australian Synchrotron.  
poster icon Poster MOPB049 [0.924 MB]  
MOPB050 Overview of Applications and Synergies of a Generic FPGA-Based Beam Diagnostics Electronics Platform at SwissFEL 1
  • W. Koprek, B. Keil, G. Marinkovic
    PSI, Villigen PSI, Switzerland
  For SwissFEL electron beam diagnostics, we combine application-specific detectors and front-end electronics with a common solution for digitization, interfacing and FPGA-based digital signal processing. Many key components and standards we use were initially developed by PSI for the European XFEL BPM system, but are equally suited for a broad range of SwissFEL diagnostics systems with little or no modifications. Examples are e.g. the FPGA signal processing hardware and firmware/software, ADC and DAC boards, interface boards or peak detection front-end electronics. By following a modular generic hardware and firmware/software design approach, we can cover a larger number of different monitor types with moderate development effort. Applications of our generic platform include BPMs, bunch length monitors, beam arrival time monitors, beam loss monitors, and digital laser phase locked loops (PLLs). This paper gives an overview of the design, present and future applications of our generic platform, discussing the synergies and differences of the required hardware, firmware and embedded software solutions.  
poster icon Poster MOPB050 [0.371 MB]  
MOPB051 System Integration of SwissFEL Beam Loss Monitors 1
  • P. Pollet, R. Ischebeck, D. Llorente Sancho, G. Marinkovic, C. Ozkan Loch, V. Schlott
    PSI, Villigen PSI, Switzerland
  Scintillator-based Beam Loss Monitors will be used at SwissFEL for monitoring the losses for optimising beam conditioning, beam measurements with the wire-scanner and Undulator protection. The optical signals from the scintillators will be detected by PMTs which are located outside the accelerator tunnel. The PMT control and signal conditioning is done via a front-end based on the PSI Analogue Carrier board. The PAC board allows for amplification/attenuation, offsetting and single-ended to differential conversion, while the Generic PSI Carrier (GPAC) board provides digitisation and FPGA-based post-processing, along with bridging the communication to EPICs controls. A fast algorithm was developed to process the signals and trigger the machine protection system (MPS) at 100Hz. The system integration of the BLMs and its results will be discussed in this paper.  
Plasma Monitor for Ultra-Short SwissFEL Electron Bunch Peak Current Measurement  
  • R. Tarkeshian, R. Ischebeck, V. Schlott
    PSI, Villigen PSI, Switzerland
  The peak current is a crucial factor in the lasing process of free electron laser (FEL). In order to obtain the high peak current, and short gain-length the electron bunch needs to be compressed. New techniques for resolving few fs or even sub-fs SwissFEL bunches are required. The electric field for the SwissFEL compressed bunch (< 20fs rms at 200 pC) is in GV/m level. Therefore it is proposed here to use SwissFEL bunches to tunnel-ionize neutral gas. The tunneling effect has exponential dependence on the electric field and bunch peak current. Therefore by characterizing the plasma emission, ion or electron wakes the bunch peak-current can be inferred. The field ionization effects can be characterized by the electron beam energy loss and a transverse size measurement upstream of the plasma cell. The PIC simulation package VSim* is used to carry out simulations of the SwissFEL beam propagating through the gas. First simulation results compared with theoretical prediction and analytical modeling as well as the proposed experimental setup will be presented.
*TECH-X, VSIM 7.2,
MOPB053 The Beam Loss Monitoring System in Taiwan Photon Source 1
  • C.H. Huang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, D. Lee, C.Y. Wu
    NSRRC, Hsinchu, Taiwan
  Taiwan photon source (TPS) is a 3rd generation and 3 GeV synchrotron light source during beam commissioning in NSRRC. Several types of beam loss monitors (BLMs) such as PIN-photodiodes, scintillation detectors, cherenkov BLMs and RadFETs are installed in the storage ring to study the beam loss distribution and mechanism. The installation infrastructure, design of reader units and integrated graphic user interface will be described in this report. The primary experimental results will also be summary here.  
poster icon Poster MOPB053 [0.656 MB]  
MOPB055 The NSRRC Photo-injector Diagnostic Tools for Initial Beam Test 1
  • A.P. Lee, M.C. Chou, N.Y. Huang, J.-Y. Hwang, W.K. Lau, C.C. Liang, M.T. Tsou
    NSRRC, Hsinchu, Taiwan
  • P. Wang
    NTHU, Hsinchu, Taiwan
  The High brightness injector project at NSRRC aims to develop a100 MeV photo-injector system for light source R&D at NSRRC. This photo-injector system equipped with a photocathode rf gun, a solenoid for emittance compensation, an S-band linac as well as various beamdiagnostic tools. In the beginning of this project, the photocathode rf gun was installed in the booster room of TLS at NSRRC. The normalized beam transverse emittance is 5.5 mm-mrad at ~250 pC with Gaussian laser pulse. Recently, a 100 MeV photo-injector system is being installed in the 38 m by 5 m tunnel of the NSRRC linac test laboratory. The rf gun, the 35 MW high power microwave system and a 5.2 m lina has been set up. The UV driver laser system will be set up in the new temperature controlled clean room in the linac test laboratory. For initial beam test, some beam diagnostic tools are considered. They are presented and discussed in this paper.  
poster icon Poster MOPB055 [1.244 MB]  
MOPB056 Improvement of Tune Measurement System at Siam Photon Source 1
  • S. Kongtawong, P. Klysubun, S. Krainara, P. Sudmuang
    SLRI, Nakhon Ratchasima, Thailand
  Funding: Synchrotron Light Research Institute (SLRI) (Thailand)
A new tune measurement system was recently developed and implemented at Siam Photon Source (SPS) for both the booster synchrotron and the 1.2 GeV electron storage ring. A new electronic module was installed at the SPS booster for collecting the turn-by-turn signal generated when the beam is excited with white noise and fast kicker. The beam excitation was carefully studied in order to determine the optimum beam response. With this system we observed the variation of the tune during energy ramping. The measurement provides information needed to optimise the working tune and to keep it constant. At the SPS storage ring, the excitation signal was changed from swept frequency signal to frequency modulation (FM) signal to reduce the measurement time. Details of the instrumentation setup and its performance will be presented in this report.
poster icon Poster MOPB056 [1.862 MB]  
MOPB057 Observation of Beam Loss Signal at the SPS Storage Ring 1
  • S. Krainara, G.G. Hoyes, P. Klysubun, S. Kongtawong, P. Sudmuang, N. Suradet, S. Teawphet
    SLRI, Nakhon Ratchasima, Thailand
  Beam Loss Monitoring (BLM) system is an essential tool for observing beam instabilities and hence for machine protection. At the Siam Photon Source (SPS) storage ring, the BLM system is used to check the beam behavior due to optics perturbation, ion trapping, and vacuum leakage. A network of 50 PIN-diode detectors from Bergoz has been installed around the ring at the positions of high particle density. These positions are at the values of large betatron and dispersion functions in the machine lattice. The operational results of tune scanning verses loss rate in the resonance diagram are described. These results will be useful for improving the beam performance in terms of lifetime and beam stability.  
poster icon Poster MOPB057 [5.516 MB]  
MOPB058 Improvement of the Siam Photon Source Beam Loss Monitor System 1
  • N. Suradet, G.G. Hoyes, P. Klysubun, S. Krainara, P. Sudmuang, S. Teawphet
    SLRI, Nakhon Ratchasima, Thailand
  A description of the newly re-built beam loss monitor (BLM) system at the Siam Photon Source (SPS) is presented. The original BLM system was designed and installed in the 1.2 GeV SPS storage ring in 2005. The main problems of this system were poor performance due to RF electromagnetic interference and the use of now obsolete data acquisition electronics. The beam loss detector used is a PIN-diode type from Bergoz. The new BLM system has been implemented using low-noise coaxial cable and an acquisition system based on NI-PXI. The hardware and software modifications incorporated into the new BLM system are presented.  
poster icon Poster MOPB058 [3.473 MB]  
FLUKA Studies of Beam Loss Diagnostics on ISIS  
  • H. V. Smith
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  The ISIS facility at the Rutherford Appleton Laboratory is a pulsed neutron and muon source for materials and life science research. Up to 3×1013 protons per pulse are accelerated to 800 MeV in the ISIS 50 Hz RCS. The maximum operating intensity of the synchrotron is limited by loss during acceleration. A suite of beam loss diagnostics is available for use on ISIS, comprising argon ionisation tubes on the inner radius of the synchrotron and organic scintillators on the inner radius of the dipole ceramic vacuum vessels. This paper introduces initial studies of these operational diagnostics with the FLUKA code: measurements of the position sensitivity of the argon ionisation tubes have been compared to simulations to increase understanding of the observed loss distributions, comparisons of the response of argon ionisation tubes and scintillator have been made, and an existing model of the ISIS collimation system has been extended and benchmarked against machine measurements in order to optimise the collimator positions.  
MOPB063 First Experimental Results with the CLIC Drive Beam Phase Feedforward Prototype at the CLIC Test Facility CTF3 1
  • G.B. Christian, P. Burrows, C. Perry, J. Roberts
    JAI, Oxford, United Kingdom
  • A. Andersson, R. Corsini, R. Corsini, J. Roberts, J. Roberts, P.K. Skowroński, P.K. Skowroński
    CERN, Geneva, Switzerland
  • P. Burrows, C. Perry
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • A. Ghigo, A. Ghigo, F. Marcellini, F. Marcellini
    INFN/LNF, Frascati (Roma), Italy
  Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no. 227579
The two-beam acceleration scheme envisaged for CLIC will require a high degree of phase stability between two beams at the drive beam decelerator sections, to allow efficient acceleration of the main beam. There will be up to 48 such decelerator sections for the full 3 TeV design, and each decelerator section will be instrumented with a feed-forward system to correct the drive beam phase to a precision of 0.2 degrees at 12 GHz relative to the main beam, using a kicker system around a four-bend chicane. A prototype system has been developed and tested at the CLIC Test Facility (CTF3) complex, where the beam phase is measured upstream of the combiner ring and corrected with two kickers in a dog-leg chicane just upstream of the CLEX facility, where the resulting phase change is measured. This prototype is designed to demonstrate correction of a portion of the CTF3 bunch train to the level required for CLIC, with a bandwidth of greater than 30 MHz, and within a latency constraint of 380 ns as set by the beam time-of-flight through the combiner ring complex. A description of the hardware will be given and initial results from the first phase of the experiment will be presented.
poster icon Poster MOPB063 [1.783 MB]  
MOPB064 Initial Work on the Design of a Longitudinal Bunch-by-Bunch Feedback Kicker at Diamond 1
  • A.F.D. Morgan, G. Rehm
    DLS, Oxfordshire, United Kingdom
  In 2017 it is planned to install some additional normal conducting cavities into the Diamond storage ring. There is some concern that higher order modes in these devices could cause longitudinal instabilities in the beam. In order to deal with this potential problem we have started work on designing a longitudinal bunch-by-bunch feedback system. This paper will concentrate on the design and simulation of the kicker cavity, which is of the overloaded cavity type.  
poster icon Poster MOPB064 [0.340 MB]  
MOPB065 Considerations and Improved Workflow for Simulation of Dissipated Power from Wake Losses 1
  • A.F.D. Morgan, G. Rehm
    DLS, Oxfordshire, United Kingdom
  At Diamond quite some effort has gone into simulating and understanding the dissipation of energy into structures induced by wake losses. Due to changes in the core simulation code we use, it is now possible to extract the dissipated energy information directly from the simulation rather than inferring it from other parts of the simulation output which was, by necessity, our previous method. Various modeled geometries will be used to illustrate the improved approach. Also, we will discuss the considerations needed when constructing the model geometries in order to get the most representative results from the simulation.  
poster icon Poster MOPB065 [0.337 MB]  
MOPB066 Streak Camera PSF Optimisation and Dual Sweep Calibration for Sub-ps Bunch Length Measurement 1
  • L.M. Bobb, A.F.D. Morgan, G. Rehm
    DLS, Oxfordshire, United Kingdom
  Streak cameras are commonly used for bunch length measurement. In normal beam modes, bunch lengths are on the order of 10 ps. For the study of microbunch instabilities, a low alpha single bunch mode is implemented with bunch lengths approaching 1 ps and beam current in the tens of microamps. In order to reliably measure such a short bunch at low beam currents, the input optics for the streak camera must be optimised for sufficient incident light intensity and high resolution in both sweep directions. This is achieved through the use of reflective input optics in which a pinhole is imaged to provide a small circular Point Spread Function. Furthermore to precisely measure the bunch length, the calibration of the dual sweep must be known. Here we describe a calibration method using electrical delays to incorporate calibration information within streak camera images.  
poster icon Poster MOPB066 [0.739 MB]  
MOPB067 Optical Diagnostics within LA3NET 1
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  Funding: This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289191.
The Laser Applications at Accelerators network (LA3NET) is a pan-European project that has received 4.6 MEUR of funding within the European Union's 7th Framework Programme. It closely links research into lasers and accelerators to develop advanced particle sources, new accelerating schemes, and in particular beyond state-of-the-art beam diagnostics. This contribution summarizes the research achievements in optical diagnostics of this 4 year research and training initiative. It presents the achievable resolution of a laser-based velocimeter to measure the velocity of neutral particle beams, results from the measurement of bunch shape using electro-optical crystals with tens of fs resolution, experimental data using a laser wire scanner, and discusses the resolution limits in energy measurements using Compton backscattering at a synchrotron light source. Finally, it also provides a summary of events that have been organized by the LA3NET consortium.
MOPB068 Advanced Beam Diagnostics R&D within oPAC 1
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  Funding: This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485.
oPAC 'Optimization of Particle Accelerators' is a European research and training network that has received funding by the EU within the 7th Framework Programme. With a total budget of 6 M' and 23 Fellows that are employed within the project, it is the largest Marie Curie network to date. oPAC was started in 2011 and will come to an end at the end of 2015. It currently joins more than 30 partner institutions from all around the world, including research centres, universities and the private sector. One of the projects largest work packages addresses advanced R&D in beam diagnostics. This includes studies into advanced instrumentation for synchrotron light sources and medical accelerators, enhanced beam loss monitoring technologies, ultra-low emittance beam size diagnostics, beam diagnostics for high intensity beams, as well as the development of compact electronics for beam position monitors. This contribution will present the research outcomes of this work package and discuss the demonstrated performance of each diagnostic. A summary of the various events the network has organized for the accelerator community will also be given.
MOPB070 FRIB Machine Protection System Design and Validation Studies 1
  • S.M. Lidia, M. Ikegami, Z. Li, Z. Liu, T. Russo, R.C. Webber, Y. Zhang, Q. Zhao
    FRIB, East Lansing, Michigan, USA
  Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University.
The FRIB heavy ion superconducting linac will present the highest peak power hadron beam facility, with beams carrying >400 kW power with kinetic energy >200 MeV/u. Fast protection systems are required to detect and remove beam within 35 us. Detection of beam losses in the low energy linac segment is confounded by two effects: small fluxes of secondary radiation from beam impacts, and large fluxes due to cross-talk from neighbouring, higher energy linac sections. We describe a machine protection scheme based on multiple families of diagnostics and diagnostic networks. On-going fault mode studies are utilised to assess risk and to assist in the definition of specific detection networks for high reliability and responsivity.
MOPB071 Overview of Beam Diagnostic Systems for FRIB 1
  • S.M. Lidia, S. Cogan, D. Constan-Wahl, J.L. Crisp, M. Ikegami, Z. Liu, F. Marti, I.N. Nesterenko, G. Pozdeyev, T. Russo, R. Shane, R.C. Webber, Y. Zhang, Q. Zhao
    FRIB, East Lansing, Michigan, USA
  Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan State University.
The Facility for Rare Isotope Beams will extend the intensity frontier of heavy ion linac facilities, with continuous beam power up to 400 kW and beam energy ≧200 MeV/u. Strict demands are placed on the beam diagnostics in the front end, linac, and beam delivery systems to ensure delivery of high quality beams to the target with minimal losses. We describe the design of diagnostic systems in each accelerator sector for commissioning and operations.
MOPB073 Cryogenic Thermometers as Slow Beam Loss Detectors 1
  • Z. Zheng, Z.Q. He, S.M. Lidia, Z. Liu, R. Shane, Y. Zhang
    FRIB, East Lansing, Michigan, USA
  Due to the folded geometry of the linac, beam loss monitoring at the Facility for Rare Isotope Beams (FRIB) [1], especially for small losses, is extremely challenging in the low energy section of the linac. Fast detection is not required for slow/small beam losses, and we therefore propose thermometers installed in the cryomodules at potential hot spots, such as the locations upstream of solenoids. Cryogenic thermometry tests were implemented in the ReA6 cryomodule with heaters and RTD thermometers. The preliminary study shows that the 10 mK signal resolution of thermometers corresponds to ~5 mW heat power in 100 seconds, or ~1 W heat power in 10 seconds, which is sufficient to satisfy the requirement for small beam loss at FRIB.  
MOPB074 Reference Signal Distribution for Beam Position and Phase Monitors at LANSCE 1
  • R.C. McCrady, H.A. Watkins
    LANL, Los Alamos, New Mexico, USA
  Funding: This work is supported by the United States Department of Energy under contract DE-AC52-06NA2596.
The new beam position and phase monitors at LANSCE measure the phase of the beam relative to a reference signal from the master reference oscillator. The distribution of the reference signal along the 800 m long linac is subject to thermal effects, and phase drifts of the reference signal are observed to be greater than 15 degrees. We are investigating stabilisation schemes, one of which involves distributing two RF signals of different frequencies. By observing the phase difference between the two signals, the phase drift of the reference signal can be deduced. Initial tests indicate that the reference can be stabilised to within 0.5 degrees using this scheme. In this paper we will present the principles of operation of this stabilisation scheme and results from tests of the system.
MOPB075 Diagnostics Challenges for FACET-II 1
  • C.I. Clarke, S.Z. Green, C. Hast, M.J. Hogan, N. Lipkowitz, G.R. White, V. Yakimenko, G. Yocky
    SLAC, Menlo Park, California, USA
  Funding: This work performed under DOE Contract DE-AC02-76SF00515.
FACET-II is a prospective user facility at SLAC National Accelerator Laboratory. The facility will focus on high energy, high brightness beams and their interaction with plasma and lasers. The accelerator is designed for high energy density electron beams with peak currents of approximately 50 kA (potentially 100 kA) that are focused down to below 10x10 micron transverse spot size at an energy of 10 GeV. Subsequent phases of the facility will provide positron beams ~5-10 kA peak current to the experiment station. Experiments will require well characterised beams however the high peak current of the electron beam can lead to material failure in wirescanners, optical transition radiation screens and other instruments critical for measurement or delivery. The radiation environment and space constraints also put additional pressure on diagnostic design.
poster icon Poster MOPB075 [0.720 MB]  
Implementation of Phase Cavity Algorithm for Beam Arrival Time Monitoring System for LCLS  
  • K.H. Kim, J.C. Frisch, B.L. Hill, S.R. Smith, E. Williams
    SLAC, Menlo Park, California, USA
  Funding: US DOE
The phase cavity system is an essential part of the femtosecond timing system for the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. Electrons exiting the LCLS undulator excite a phase cavity which measures the electron beam time relative to a phase reference line from the accelerator. Beam phase measured by the cavity is very sensitive to the cavity resonant frequency. We compensate for this effect by measuring cavity frequency on each beam pulse and correct the measured phase using calibration data, giving more accurate phase for the reference line feedback. We implement major numerical calculations and slow feedback in a processor separate from the phase cavity real-time system to avoid real-time performance dragging for shot to shot phase measurements. The new algorithm also reduces down the computational complexity of the real-time system to O(N) from O(N log N) comparing to the current implementation. The reliability of algorithm and exception handling for the communication between those systems is important. We describe implementation details and improvements in this poster.
poster icon Poster MOPB076 [1.626 MB]  
Design and Commissioning of in-Vacuum Martin-Puplett Interferometer at Elbe Facility  
  • P.E. Evtushenko
    JLab, Newport News, Virginia, USA
  • J. Hauser, R. Schurig
    HZDR, Dresden, Germany
  ELBE is an SRF LINAC based multipurpose user facility delivering electron beam with average current of up to 1 mA and beam energy of up to 40 MeV. During routine operation with thermionic triode gun the accelerator can operate with the RMS bunch length in the range from a few hundred fs to a few ps. The latest addition to the facility is a beam line for THz radiation generation. By design the beam line needs to operate with the RMS bunch length as short as 200 fs. In-vacuum Martin-Puplett interferometer (MPI) for bunch length measurements in the aforementioned bunch length range was designed, constructed, and commissioned with beam. In this contribution we describe the instrument and its design considerations. We also present bunch length measurements obtained during commissioning of the MPI with beam. RSM bunch length in the range from sub-600 fs to ~2 ps was measured. In this range we observe that the MPI can easily measure bunch length change of about 25 fs. At this point the measured bunch length range is attributed to the beam dynamics limitations rather than to the instrument itself. The instrument systematics, alignment, and further commissioning plans are discussed as well.  
MOPB081 Sub-Picosecond Shot-to-Shot Electron Beam and Laser Timing Using a Photoconductive THz Antenna 1
  • E.J. Curry, P. Musumeci
    UCLA, Los Angeles, California, USA
  • B.T. Jacobson, A.Y. Murokh
    RadiaBeam, Santa Monica, California, USA
  Temporal synchronization systems, which measure electron beam time of arrival with respect to a laser pulse, are critical for operation of advanced laser-driven accelerators and light sources. State-of-the-art synchronization tools, relying on electronic e-beam response and photodetector laser response are limited to few GHz bandwidths in most practical configurations. This paper presents a temporal diagnostic instrumentation based upon a photoconductive THz antenna, which could offer an inexpensive and user friendly method to provide shot-to-shot relative time of arrival information with sub-picosecond accuracy. We describe the overall instrument design and proof-of-concept prototype results at the UCLA PEGASUS facility.  
MOPB082 NSLS2 Fill Pattern Monitor and Control 1
  • W.X. Cheng, B. Bacha, Y. Hu, O. Singh, G.M. Wang
    BNL, Upton, Long Island, New York, USA
  NSLS2 storage ring has harmonic number of 1320. Possible fill patterns include multi bunch train(s) followed by ion cleaning gap(s), hybrid fill with single bunch in the ion gap. Storage ring filling pattern can be measured using button BPM sum signal together with high speed digitizer or oscilloscope. Button BPM sum signal typically has dynamic range of 10-2 to 10-3. Nonlinearity of BPM sum signal dependence on beam position has been characterized. In preparation for high dynamic single bunch current measurement, a filling pattern monitor system using synchrotron radiation is under development. Besides, the storage ring filling pattern can be controlled using the bunch cleaning function integrated in the bunch-by-bunch feedback system. Results of these two filling pattern monitors and bunch cleaning will be presented.  
MOPB083 Longitudinal Bunch Profile Measurement at NSLS2 Storage Ring 1
  • W.X. Cheng, B. Bacha, A. Blednykh, Y. Li, O. Singh
    BNL, Upton, Long Island, New York, USA
  Longitudinal bunch profile has been measured at NSLS2 storage ring using streak camera. From the measured profile, bunch lengthening and synchronous phase information can be derived to study the single bunch collective effect. Single bunch lengthening effect has been measured for bare lattice and for other lattices with different insertion devices. The streak camera can also be setup for other beam physics studies, for example to measure the injection beam dynamics and fast ion effects. Y-z imaging was measured using cylindrical lenses. Single bunch y-z profile was measured at threshold current.  
Instrumentation Options for the Australian Synchrotron SLED cavity upgrade  
  • P.A. Corlett
    ASCo, Clayton, Victoria, Australia
  • G. LeBlanc, K. Zingre
    SLSA, Clayton, Australia
  The Australian Synchrotron Light Source has been operating successfully since 2007 and in top-up mode since 2012 with excellent beam availability exceeding 99%. Considering the ageing of the equipment, effort is required in order to maintain the reliability at this level. The proposed upgrade of the linac with a SLED cavity system will require new RF diagnostic systems to be developed. This major upgrade will bring an opportunity to invest in new FPGA based digital hardware which will benefit both RF and beam diagnostics.