A   B   C   D   E   F   G   H   I   K   L   M   N   O   P   Q   R   S   T   U   V   W  

monitoring

Paper Title Other Keywords Page
MOPC103 Short Circuit Tests: First Step of LHC Hardware Commissioning Completion controls, extraction, dipole, quadrupole 304
 
  • B. Bellesia, E. Barbero-Soto, F. Bordry, M. P. Casas Lino, G.-J. Coelingh, G. Cumer, K. Dahlerup-Petersen, J.-C. Guillaume, J. Inigo-Golfin, V. Montabonnet, D. Nisbet, M. Pojer, R. Principe, F. Rodriguez-Mateos, R. I. Saban, R. Schmidt, H. Thiesen, A. Vergara-Fernández, M. Zerlauth
    CERN, Geneva
  • A. Castaneda, I. Romera Ramirez
    CIEMAT, Madrid
  The Large Hadron Collider operation relies on 1232 superconducting dipoles with a field of 8.33T and 400 superconducting quadrupoles with a strength of 220 T/m powered at 12kA, operating in superfluid He at 1.9K. For dipoles and quadrupoles as well as for many other magnets more than 1700 power converters are necessary to feed the superconducting circuits. Between October 2005 and September 2007 the so-called short circuit tests were carried-out in the 15 underground areas where the power converters of the superconducting circuits are located. The tests were aimed at the qualification of the normal conducting components of the circuits: the power converters, the normal conducting DC cables between the power converters and the LHC cryostat, the interlocks and energy extraction systems. In addition, the correct functioning of the infrastructure systems (AC distribution, water and air cooling, control system) were validated. The final validation test for each underground area was the powering of all converters at ultimate current during 24h. This approach highlighted a few problems that were solved long before the beginning of magnet commissioning and beam operation.  
 
MOPD027 AMC-based Radiation Monitoring System radiation, controls, power-supply, electron 505
 
  • D. R. Makowski, A. Napieralski, A. Piotrowski
    TUL-DMCS, Łódź
  • S. Simrock
    DESY, Hamburg
  This paper reports a novel radiation monitoring system able to monitor gamma and neutron radiation in an accelerator tunnel in the nearest proximity of the electronic components of the control system. The monitoring system is designed as an Advanced Mezzanine Module (AMC) and it is dedicated for the Low Level Radio Frequency (LLRF) control system based on the Advanced Telecommunication Computing Architecture (ATCA). The AMC module is able to communicate with LLRF control system using both I2C interface defined by Intelligent Platform Management Interface (IPMI) standard and PCI Express. The measured gamma radiation dose and neutron fluence are sent to data acquisition computer using Ethernet network and stored in a database. Static Random Access Memory (SRAM) is applied as a neutron dosimeter. The principle of the detector is based on the radiation effect initiating the Single Event Upsets (SEUs) in a high density microelectronic SRAMs. A well known RadFET dosimeter is used to monitor gamma radiation.  
 
MOPD028 Radio Frequency Power Sources for the Muon Ionisation Cooling Experiment power-supply, cathode, vacuum, controls 508
 
  • J. F. Orrett, P. A. Corlett, A. J. Moss, J. H.P. Rogers
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • C. J. White
    STFC/DL, Daresbury, Warrington, Cheshire
  For any future Neutrino Factory the accelerator aperture will be a major cost driver. Potentially the aperture can be reduced and significant capital savings made if ionisation cooling is utilised on the muon beam. In order to demonstrate the effectiveness of ionisation cooling a demonstrator needs to be built and operated. MICE, the Muon Ionisation Cooling Experiment is that demonstrator. The RF requirements of MICE will be met using high power vacuum tube based RF circuits donated by LBNL and CERN. This paper will discuss these circuits, their refurbishment, the construction of HT power supplies and ancillary equipment and high power testing.  
 
MOPD030 The LHC radiation monitoring system for the environment and safety: from design to operation radiation, controls, injection, collider 514
 
  • L. Scibile, D. Forkel-Wirth, H. G. Menzel, D. Perrin, G. Segura Millan, P. Vojtyla, M. Widorski
    CERN, Geneva
  The RAdiation Monitoring System for the Environment and Safety (RAMSES) has been installed and successfully commissioned. The system was originally designed for the Large Hadron Collider (LHC), it was extended to the CNGS and it is also planned to further extend it to the rest of the CERN accelerators. This state-of-the-art radiation monitoring and alarm system provides permanent ambient dose equivalent rates and ambient dose equivalent measurement in the underground areas as well as on the surface inside and outside the CERN perimeter; it permanently monitors air and water released from the LHC and CNGS installations; it also integrates some conventional environmental measurement such as physicochemical parameters of released water. This paper illustrates the experience gained during the various project phases outlining the problems encountered and the solutions implemented. In addition, it gives a first feedback on the operational experience gained with the CNGS.  
 
MOPD037 Safety Testing for LHC Access System controls, site, simulation, extraction 532
 
  • F. Valentini, T. Ladzinski, P. Ninin, L. Scibile
    CERN, Geneva
  This paper presents the validation and verification activities carried out for the LHC Access Control and Safety System. It also presents a new strategy for the future that includes the application of formal methods based on model checking techniques, commonly used to prove the correctness of software algorithms or system functional specifications through automatic exploration of the system state space. We will show how to apply these techniques in order to automate the testing process. The paper also presents the results of the performances and the applicability of a series of tools that have been tested in order to carry out a formal correctness proof for the LHC Access System.  
 
MOPD038 First Radiation Monitoring Results During Elettra Booster Commissioning radiation, booster, injection, shielding 535
 
  • K. Casarin, E. Quai, S. Sbarra, G. Tromba, A. Vascotto
    ELETTRA, Basovizza, Trieste
  The new injection system for the Elettra storage ring is based on a 100 MeV linac and a booster synchrotron, where the electron energy can be raised up to 2.5 GeV. The new machine is designed to perform full energy injection, also in top-up mode. Outside the shielding, radiation monitoring is performed through a real-time network of gamma and neutron dosimeters as well as through TLD passive dosimeters. The radiation monitors placed next to the beamlines are interlocked with the machine operation and prevent injection into the storage ring if the alarm threshold is exceeded. This paper reports the first results of the radiation monitoring performed during the new injector commissioning.  
 
MOPP044 Cavity Diagnostic System for the Vertical Test of the STF Baseline 9-cell Cavity at KEK electron, controls, diagnostics, survey 643
 
  • Y. Yamamoto, H. Hayano, E. Kako, S. Noguchi, M. Satoh, T. Shishido, K. Umemori, K. Watanabe
    KEK, Ibaraki
  • S.-I. Moon
    POSTECH, Pohang, Kyungbuk
  • H. Sakai, K. Shinoe
    ISSP/SRL, Chiba
  • Q. J. Xu
    IHEP Beijing, Beijing
  Four 9-cell cavities, which are TESLA-type 9-cell cavities, were developed and tested in KEK for the future ILC project. A simple cavity diagnostic system was introduced to search the heating spot and to detect the x-ray emission. It is composed of the carbon resistors and the PIN photo diodes. They were attached on the equator of the cell, around the HOM couplers and on the end flanges. They were very effective to search the heating spot and to detect the x-ray emission during the vertical tests. All cavities eventually had the heating spot around the equator in the final state of the vertical test. It is conceivable that the quality of the electron beam welding was somewhat poor, when the dumbbells were connected. On this February, a new vertical test facility will be completed in STF (Superconducting RF Test Facility). Six 9-cell cavities will be tested by using the new system for S0 plan, which goal is the higher accelerating gradient for ILC. The new temperature and x-ray mapping system and new DAQ system will be introduced. This paper reports the recent status in the new vertical test facility in KEK-STF.  
 
MOPP110 The SNS Resonance Control Cooling System Control Valve Upgrade Performance controls, resonance, linac, feedback 814
 
  • D. C. Williams, J. P. Schubert, J. Y. Tang
    ORNL, Oak Ridge, Tennessee
  The normal-conducting linac of the Spallation Neutron Source (SNS) uses 10 separate Resonance Control Cooling System (RCCS) water skids to control the resonance of 6 Drift Tube Linac (DTL) and 4 Coupled Cavity Linac (CCL) accelerating structures. The RCCS water skids use 2 control valves; one to regulate the chilled water flow and the other is used to bypass water to a heat exchanger. These valves have hydraulic actuators that provide position and feedback to the control system. Frequency oscillations occur using these hydraulic actuators due to their coarse movement and control of the valves. New air actuator control positioners have been installed on the DTL3 RCCS water skid to give finer control and regulation of DTL3 cavity temperature. This paper shows a comparison of resonance control performance for two valve configurations.  
 
MOPP121 Full Real-time Temperature Mapping System for 9-cell ILC-type Cavities power-supply, radio-frequency 841
 
  • A. Canabal, F. L. Krawczyk, R. J. Roybal, J. D. Sedillo, T. Tajima
    LANL, Los Alamos, New Mexico
  • S. Cohen
    Bira, Albuquerque, New Mexico
  • W. Haynes
    Fermilab, Batavia, Illinois
  The mapping of outer-wall temperatures during the vertical test of a superconducting radio-frequency (SRF) cavity has been one of the most successful tools in detecting the cavities’ critical hot spots. However, due to the excessive number of sensors needed, no fixed-type temperature mapping (T-mapping) system that covers all cells has been built for 9-cell cavities. With the consensus that T-mapping analysis is needed in order to improve the yield of high-gradient cavities, a system with a reduced data acquisition time and increased temperature sensitivity, compared to rotating-arm systems, has been developed at Los Alamos National Laboratory. The system consists of ~5,000 100 Ω 1/8W Allen-Bradley resistors placed azimuthally every 10 degrees, a similar number of other resistors and diodes that implement the switching scheme, and data acquisition codes written in Labview. The details of the system and first results are presented and discussed.  
 
MOPP129 Compensation of Lorentz Force Detuning for SC Linacs (with Piezo Tuners) controls, linac, resonance, radio-frequency 862
 
  • M. K. Grecki, J. Andryszczak, T. Pozniak, K. P. Przygoda, P. M.S. Sekalski
    TUL-DMCS, Łódź
  The superconducting linacs use niobium cavities working with extremely high quality factor. Therefore the bandwidth of the cavity is very narrow and even subtle deformation caused by Lorentz force detunes the cavity a lot. For high gradient operation (over 15MV/m) the mechanical deformation of the cavity should be compensated by piezo tuner*. The paper presents design of a piezo control system and the results of measurements of its efficiency. It was demonstrated in FLASH accelerator that an initial detuning of 300Hz can be compensated by single pulse excitation of the piezo. The described system consist of multichannel programmable pulse generator driving a 8 channel piezo amplifiers capable to supply piezos with pulses up to 1A and up to 80V. It can compensate for Lorentz force detuning in all three FLASH cryhomodules equipped with piezos (ACC3,5,6).

*Liepe et al. "Dynamic Lorentz Force Compensation with a Fast Piezoelectric Tuner," PAC2001, pp. 1074-1076.

 
 
MOPP161 Plasma Etching Rates and Surface Composition of Bulk Nb Treated in Ar/Cl2 Microwave Discharge plasma, electron, survey, ion 928
 
  • M. Raskovic, S. Popovic, J. Upadhyay, L. Vuskovic
    ODU, Norfolk, Virginia
  • H. L. Phillips, A-M. Valente-Feliciano
    Jefferson Lab, Newport News, Virginia
  To achieve theoretically predicted values of the accelerating fields in superconducting radiofrequency (SRF) cavities, their inside surface should be fairly smooth and free of impurities. Thus, surface preparation is the critical step in production of SRF cavities. Plasma etching process is a dry chemistry technique that can be used to achieve these requirements. It is based on interaction between reactive halogen species produced in the glow discharge and the surface. During this process, volatile Nb halides are evaporated from the surface of Nb, removing the mechanically damaged and contaminated layer. We present treatment of bulk Nb samples in the Ar/Cl2 microwave discharge. We achieved etching rates comparable to the rates obtained with the electropolishing method without introducing impurities in Nb. The rate dependence on various discharge parameters and reactive gas composition is presented. Surface composition and topology measurements were carried out before and after plasma treatment to determine level of impurities. Optimal experimental conditions determined on samples will applied be on single cell cavities, pursuing improvement of their RF performance.  
 
MOPP166 Control System for a PEFP FPC Baking System controls, vacuum, proton, superconductivity 940
 
  • L. Zhang, S. An, Y.-S. Cho, Y. M. Li, Y. Z. Tang
    KAERI, Daejon
  In order to bake PEFP Fundamental Power Couplers (FPC) before their RF conditioning, a PEFP baking system has been designed. A control system for the baking system has been completed by using the Labview 8.2 and A-B SLC-500 PLC. In this paper, the server and client communication technology based on OLE for a Process Control (OPC) and a Labview 8.2 Datalogging and Supervisory Control (DSC) Module are described. The program for the SLC-500 PLC with four I/O modules has been written. The mechanical design and control process are described.  
 
TUOCM02 X-ray Monitor Based on Coded-aperture Imaging for KEKB Upgrade and ILC Damping Ring photon, optics, damping, synchrotron 1029
 
  • J. W. Flanagan, H. Fukuma, S. Hiramatsu, H. Ikeda, K.-I. Kanazawa, T. Mitsuhashi, J. Urakawa
    KEK, Ibaraki
  • J. P. Alexander
    CLASSE, Ithaca
  • M. A. Palmer
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • G. S. Varner
    UH, Honolulu, HI
  We present here design considerations for an x-ray monitor for high-resolution (a few um) and fast response (sub-nanosecond) for beam profile measurements to be used at an upgraded KEKB and/or ILC damping ring. The optics for the monitor are based on a technique borrowed from x-ray astronomy, coded-aperture imaging, which should permit broad-spectrum, low-distortion measurements to maximize the observable photon flux per bunch. Coupled with a high-speed digitizer system, the goal is to make sub-bunch-length, turn-by-turn measurements of beam profile and position.  
slides icon Slides  
 
TUPC003 Libera Grouping: Reducing the Data Encapsulation Overhead feedback, brilliance, controls, instrumentation 1041
 
  • A. Bardorfer, T. Karcnik
    Instrumentation Technologies, Solkan
  • K. T. Hsu
    NSRRC, Hsinchu
  Libera Brilliance is a precision digital Beam Position Monitor, a building block for modern fast orbit feedback systems. Gigabit Ethernet and UDP/IP protocol are used as a standard data link for real-time beam position signal transmission to the central fast feedback CPU engines. While the UDP/IP over Gigabit Ethernet provides a standardized and proven solution that enables the utilization of COTS components, the UDP and IP protocols are subject to a large data encapsulation overhead, since the beam position data payload is relatively small. To overcome this, several Libera Brilliance units (up to 16) have been grouped together in a redundant private network via the LC optical links and/or copper “Molex” cables. The purpose of the private network is to exchange the data among the Libera Brilliance units without the protocol overhead and send the gathered data via Gigabit Ethernet. Any of the Libera Brilliance units in a group can act as a Gigabit Ethernet group transmitter. The private network is redundant and can survive a single cable failure. The data encapsulation overhead has been significantly reduced. Libera Grouping is being tested at NSRRC, Taiwan.  
 
TUPC028 Design and Construction of an Inductive Pick-up for Beam Position Monitoring in the TBL Line of the CTF3 pick-up, vacuum, linac, electron 1110
 
  • J. J. Garcia-Garrigos, J. V. Civera-Navarrete, A. Faus-Golfe
    IFIC (CSIC-UV), Valencia
  In order to determine the beam position respect to the vacuum chamber, the IPU senses the azimuthal distribution of the beam image current flowing along its inner wall when a high frequency bunched beam passes through. The inner wall of the pick-up is divided into four electrodes, each of which forms the primary winding of a toroidal transformer. Therefore the beam image current component flowing through each electrode is transformed to a secondary winding connected to a pick-up output. The closer the beam is to the transformer electrode, the greater is the induced signal in its secondary winding. This basic sensing mechanism will allow to determine the beam position through the four transformers distributed orthogonally around the vacuum pipe. The bandwidth of the IPU and the amplifier is set above 200 MHz to let pass, with low distortion, the 20-140 ns pulse train signal induced from the beam. Also, its expected resolution at maximum current is 5μm. This paper reports on the design, construction as well as testing and calibration processes of two IPU prototypes. They will be installed in the Test Beam Line (TBL) of the 3rd CLIC Test Facility (CTF3) at CERN by Spring 2008.  
 
TUPC031 Longitudinal Beam Diagnostics Application of Synchrotron Radiation at FLASH radiation, synchrotron, synchrotron-radiation, electron 1116
 
  • O. Grimm, J. Rossbach
    Uni HH, Hamburg
  • C. Behrens, B. Schmidt
    DESY, Hamburg
  For the operation of the FLASH free electron laser at DESY, Hamburg, tools to measure the longitudinal charge distribution and especially its stability over time are important for efficient machine running. Several techniques using both coherent far-infrared and incoherent visible synchrotron radiation from the two bunch compressor chicanes are summarized and compared in this paper. The experimental setups used are
  1. a Martin-Puplett interferometer with both a room-temperature pyroelectric and a liquid-Helium cooled bolometer as detector,
  2. a streak camera to directly measure the time profile,
  3. the analysis of intensity fluctuations of the optical synchrotron radiation measured (with a photomultiplier) through a narrow filter,
  4. a single shot grating spectrometer covering the spectral range from 5 μm to 150 μm.
Data from the various and complementary experimental methods will be presented and compared. 		 
 
TUPC050 A Complete Solution for Beam Loss Monitoring beam-losses, controls, vacuum, injection 1170
 
  • M. Kobal, J. Dedic, R. Stefanic
    Cosylab, Ljubljana
  • J. F. Bergoz
    BERGOZ Instrumentation, Saint Genis Pouilly
  In particle accelerator facilities knowing the beam loss is crucial for the machine to be running at optimal efficiency. Beam loss can be monitored on different time scales. Time scale of seconds is used at normal operation to detect any irregularities such as changes in the beta function or vacuum drop. Time scale of 1 ms is used to optimize injection, and 1 μs timescale in case of severe problems when the beam does not live for more than a couple of turns. The presented beam loss system (microIOC-BLM) uses Bergoz BLM sensors, Beam loss Signal Conditioner (BSC) for data acquisition and microIOC-CosyIcon as the central processing unit. The system is cost effective, portable and can be expanded with additional measuring points. Selectable counting interval from 100 μs to 10 s covers a large part of the required time scales. The minimum and maximum count rates are limited by the sensor between 1/s to 10 M./s. Trigger and gate signals are supported as is summing over a number of measurements.  
 
TUPC052 Beam Phase and RF Fields Monitoring System Using Lock-In Amplifier for RIBF cyclotron, acceleration, ion, linac 1173
 
  • R. Koyama, M. K. Fujimaki, N. Fukunishi, M. Hemmi, O. Kamigaito, M. Kase, Y. Kotaka, N. S. Sakamoto, K. Suda, T. Watanabe, K. Yamada, Y. Yano
    RIKEN, Saitama
  The accelerator complex of the RIKEN RI Beam Factory (RIBF) consists of two injectors - heavy ion linac (RILAC and CSM) and K78 MeV AVF cyclotron - and four cyclotrons from the upstream, RRC (K540 MeV), fRC (K570 MeV), IRC (K980 MeV), and SRC (K2600 MeV). In such a multi-stage acceleration system, one of the most important factors for stable operation is to maintain the matching of beam-phases between accelerators. However, drifts of beam-phases have been frequently observed, reasons of which might be the fluctuation of RF-fields, variation of magnetic field, and so on. Hence, it is important to monitor beam-phases constantly, and we have developed a monitoring system using the commercial RF lock-in amplifier model SR844 manufactured by Stanford Research Systems. In addition, the system for monitoring the RF-fields has also been developed to investigate its stability and the correlation with beam-phases. The beam-phases at eleven phase probes installed in the beam transport lines and RF-fields of 25 cavities are monitored in a uranium acceleration. In addition, lock-in amplifiers are also used to obtain good isochronous magnetic fields of three cyclotrons in the RIBF.  
 
TUPC094 Longitudinal Bunch Profile Monitoring via Single Shot Diagnostic with Linear Response electron, laser, diagnostics, polarization 1278
 
  • U. Schmidhammer, V. De Waele, J.-P. Larbre, J.-L. Marignier, H. Monard, M. Mostafavi
    CLIO/ELISE/LCP, Orsay
  • N. Bourgeois, J.-R. Marquès
    LULI, Palaiseau
  A new approach of electro-optic (EO) spectral encoding allows for the non-invasive characterization of the longitudinal electron bunch distribution at the ELYSE laser triggered ps pulse radiolysis facility: the transverse electric field of the relativistic bunch is encoded to the temporally dispersed spectrum of a supercontinuum whose wavelength dependent polarisation state is then analyzed with balanced detection. This method combines the spectral bandwidth of the probe that corresponds to a Fourier transform limit < 5 fs with a direct signal response of the detection scheme. As a result, the field amplitude within the EO crystal can be determined in an absolute, undistorted manner with a time window several times longer than the electron pulse. For a time window easily tunable between 0.5 to 100 ps the possible time resolution is ~ 70 fs respectively 1 ps. The diagnostic allows bunch monitoring at the 100 pC level even for low beam energy and brightness. The influence of the accelerator conditions on the charge profile and its stability was able to be studied for the 8 MeV bunches at ELYSE with a 0.5 mm thick ZnTe crystal in a distance of 4 mm to the beam centre.  
 
TUPC107 Feed-free Monitoring of Intense High-energy Bremsstrahlung electron, radiation, simulation, linac 1311
 
  • V. L. Uvarov, V. I. Nikiforov, V. A. Shevchenko, I. N. Shlyakhov, A. Eh. Tenishev
    NSC/KIPT, Kharkov
  High-intensity (>103 W/cm2) bremsstrahlung sources produced on the basis of electron linacs of energy E0 up to 100 MeV find use in accelerator-driven subcritical assemblies, in photonuclear isotope production, activation analysis, etc. These processes, as a rule, call for maintaining a stable bremsstrahlung flow for one or more days. Therefore the diagnostic means of the radiation must function reliably under conditions of high-absorbed doses (≥108 Gy). To solve the problem, it is proposed to use a direct charge detector (DCD). It consists of two vacuum gap-spaced metal plates of different thickness. The simulation method based on the software PENELOPE/2006 was used to investigate the conditions of equilibrium e, X-radiation formation in the area of detector location, the dependence of detector sensitivity in its standard geometry on the atomic number Z of the plate material and the gammas energy at E0 ranging from 20 to 100 MeV. The realization of the method has been demonstrated by experiment with the use of the DCD prototype. The proposed detector requires no external power supply, is easy to operate and has a high radiation resistance.  
 
TUPC121 Nanometre Precision Interferometric Stability Monitoring Systems for Key Accelerator Components laser, quadrupole, alignment, linear-collider 1350
 
  • P. A. Coe, A. Reichold, D. Urner
    OXFORDphysics, Oxford, Oxon
  • M. S. Warden
    JAI, Oxford
  The MONALISA group develops novel, accurate, nanometre resolution, interferometric systems to monitor relative motions between key accelerator components. We use cost-effective technology developed for the telecommunications market, providing readily scalable, adaptable solutions. Key magnets and diagnostics in the beam-delivery section of the International Linear Collider (ILC) will need to maintain stable relative positions. In particular, the final focus quadrupole magnets require nanometre level stability. Even greater stability requirements will be placed on components for the Compact Linear Accelerator (CLIC). Interferometers provide the only means of monitoring relative positions over long timescales, at the nanometre and sub-nanometre level. We are working to improve our measurement resolution using an optical frequency reference obtained by locking the second harmonic of an ultra-narrow linewidth 1560 nm fibre laser to a D2 transition in Rubidium-87. The latest results from this system tested on novel design, fibre-coupled, evacuated interferometers will be presented.  
 
TUPC129 LHC Access System: from Design to Operation controls, radiation, injection, site 1371
 
  • T. Pettersson, C. Delamare, S. Di Luca, S. Grau, T. Hakulinen, L. Hammouti, F. Havart, J.-F. Juget, T. Ladzinski, M. Munoz Codoceo, P. Ninin, R. Nunes
    CERN, Geneva
  The paper describes the LHC access control and safety system project, the system's architecture and the experience gathered of commissioning it. This system is made of two parts: the LHC Access Control System and the LHC Access Safety System. Using state of the art redundant, fail-safe PLC's and a supplementary, cabled control loop the LHC Access Safety System guarantees the safety of the personnel in all events. Using industrial components, the LHC Access Control System, regulates the access to the tunnels and experimental areas by identifying the users and checking their authorisations. It allows a remote or automatic operation of the access control equipment and restricts the number of users working simultaneously in the interlocked areas. A first implementation of the architecture is now in production and ensures that only authorized personnel can enter the controlled areas of the LHC complex and this only after permission has been given by the CERN Control Centre. The design, procurement and installation of the entire system took more than 4 years and the commissioning phase lasted about 12 months.  
 
TUPC140 The Spallation Neutron Source Cryomodule Test Stand RF System controls, klystron, linac, radio-frequency 1395
 
  • M. T. Crofford, T. W. Hardek, D. Heidenreich, Y. W. Kang, K.-U. Kasemir, S.-H. Kim
    ORNL, Oak Ridge, Tennessee
  • J. A. Ball, T. L. Davidson
    ORNL RAD, Oak Ridge
  The Spallation Neutron Source (SNS) has recently commissioned a cryomodule test facility for the repair and testing of the super-conducting cryogenic cavities. This facility utilizes the original 402.5/805 MHz Radio Frequency (RF) Klystron Test Stand as its power source along with dual Low Level RF (LLRF) control systems. One control system is based on the standard SNS Linac LLRF controls with a second system for open-loop only control. The system is designed to allow simultaneous testing of devices in the test cave and other devices which can be tested outside of the enclosure. Initial tests have shown good results; some improvements are yet to be implemented. This paper will provide an overview of the RF systems, safety systems, and interlocks.  
 
TUPC141 Concept and Implementation of the SC Cavity Resonance Frequency Monitor for the Digital RF Field Controller controls, resonance, klystron, laser 1398
 
  • W. Jalmuzna, A. Napieralski
    TUL-DMCS, Łódź
  • S. Simrock
    DESY, Hamburg
  New generations of digital control systems offer large number of computation resources together with precise ADCs (analog to digital converters) and DACs (digital to analog converters) which can be used to generate almost any klystron driving signal. This gives the possibility to implement such features as digital SEL (self excited loop) and frequency sweep mode. They can be used to monitor resonance frequency of SC cavities. This information can be used by tuning system to adjust cavity tuner settings. Such functionality is valuable especially during the first RF station start up when the cavities may be detuned even by a large frequency. The paper presents the concept of such system and summarizes implementation and tests performed at FLASH facility (DESY, Hamburg).  
 
TUPC153 Hardware-software Simulation for LLRF Control System Development simulation, controls, feedback, radio-frequency 1428
 
  • A. Vaccaro, L. R. Doolittle, A. Ratti, C. Serrano
    LBNL, Berkeley, California
  Field Programmable Gate Arrays (FPGA) have been used in accelerator controls for a long time. Stricter performance requirements in new accelerator designs force LLRF control systems to continuously improve, and the increasing density of available FPGAs enables such progress. The increased complexity in FPGA design is not always followed by new RF systems availability for development and testing. Therefore, a hardware-software simulation tool has been developed to model RF systems by a software simulator. It simulates the interaction of HDL code that is to be synthesized with both RF systems and communication ports to external controls software, reproducing realistic working conditions of the FPGA. The hardware-software interaction for LLRF control system design is discussed here.  
 
TUPP011 The ESRF Temperature Monitoring System from an Operational Point of View vacuum, radiation, controls, survey 1547
 
  • D. Schmied, E. Burtin, J. M. Chaize, R. Kersevan, I. Parat, M. Peru, J. L. Pons
    ESRF, Grenoble
  The vacuum control system of the ESRF electron Storage Ring (SR) is in operation since more than ten years now. Apart from difficulties to have appropriate support for the old system, we start facing problems of aging and obsolescence. We have been reviewing our philosophy of data acquisition and remote control in order to upgrade our systems with state of the art technology by taking into account our operational experience. We have installed shielded "intelligent" devices inside the SR and took advantage of the latest developments linked to new communication technologies and standards, such as TCP/IP MODbus protocol and WEB server based instrument control. This presentation outlines our present work dedicated to the ESRF temperature acquisition system based on Programmable Logic Controllers (PLC), and new developments regarding the user interface in the control room. Several examples show the importance of surveying the temperatures in order to identify various mechanical or operational problems which allow us to anticipate later failures and provide us with an additional machine diagnostic tool.  
 
TUPP013 Synchronized Data Distribution and Acquisition System Using Reflective Memory for J-PARC 3GeV RCS controls, linac, acceleration, beam-losses 1553
 
  • H. Takahashi, N. Hayashi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • M. Sugimoto
    Mitsubishi Electric Control Software Corp, Kobe
  J-PARC 3GeV RCS inject the different parameter beam to each facilities, which are MLF and MR. Therefore, 3GeV RCS Control System must realize the monitoring and the operation that are distinguished "MLF beam" from "MR beam". And, we have developed the data distribution and acquisition system for "synchronized data" which required the distinguished monitoring and operation. We have designed and developed distribution and acquisition system using Reflective Memory (RM) for BPM data, which is one of synchronized data. There are 54 BPM, and BPM signal is processed by each BPM signal circuit (total 54 circuits). Then, we have designed that RM have 54 virtual ring memories and for a few seconds BPM data pre one virtual ring memory is buffered. And we decide BPM data is written virtual ring memory position based on "beam tag", which distributed from RM of J-PARC Timing System. This "beam tag" is synchronized across J-PARC. Thereby, 54 BPM data that written same virtual ring memory position become BPM data for identical beam. The paper presents the current status of the synchronized data distribution and acquisition system using RM.  
 
TUPP027 Electron Energy Dependence of Scrubbing Efficiency to Mitigate E-cloud Formation in Accelerators electron, vacuum, simulation, luminosity 1592
 
  • R. Cimino, M. Commisso, T. Demma, A. G. Grilli, P. Liu, M. Pietropaoli, V. Sciarra
    INFN/LNF, Frascati (Roma)
  • V. Baglin
    CERN, Geneva
  • P. Barone, A. Bonanno
    INFN Gruppo di Cosenza, Arcavacata di Rende (Cosenza)
  Recently built and planned accelerators, base their ability to reach design parameters, on the capability to reduce Secondary Electron Yield (SEY) during commissioning, hence mitigating the potentially detrimental effects of e-cloud driven machine limitations. This SEY reduction (called "scrubbing"), is due to the fact that the electrons of the cloud, hit the vacuum chamber wall, modifying its surface properties and reducing its SEY. This minimise any disturbing effects of the e-cloud to the beam. "Scrubbing" has been studied only as a function of impinging electron dose. In reality SEY modifications are only studied by bombarding surfaces with 300-500 eV electrons, but no scrubbing dependence on the bombarding electron energy has ever been discussed. The actual energy of the electrons of the cloud hitting the wall in real accelerators has never been measured accurately, while simulations predict very low electron energies (<50 eV). For this reason and given the peculiar behaviour observed for low energy electrons*, we decided to study this dependence accurately. Here we present some preliminary results discussing eventual implications to machine commissioning procedures.

*R. Cimino et al. Phys. Rev. Lett 93, 14801 (2004).

 
 
WEPC029 Assessment of the Impact of External Stimuli on the Floor Stability of Diamond survey, storage-ring, damping, site 2049
 
  • J. Kay, H. C. Huang
    Diamond, Oxfordshire
  • R. Bartolini
    JAI, Oxford
  Continuous vibration monitoring is carried out and the stability of the Diamond floor slab has been assessed with regard to how it has responded to various external stimuli. Data has been collected on weather conditions and comparison made at extremes with floor vibration. The impact of a high level walkway bridge on the hall floor has also been assessed and there was a unique opportunity for an operational facility to measure the vibration response during a complete power black-out. The impact of local construction work is also presented.  
 
WEPC109 Development of an In-vacuum Undulator System for U-SAXS Beamline at PLS undulator, controls, vacuum, ion 2255
 
  • D. J. Waterman, A. Deyhim, J. Kulesza, E. Van Every
    Advanced Design Consulting, Inc, Lansing, New York
  • K. I. Blomqvist
    MAX-lab, Lund
  The design of a hybrid in-vacuum undulator with 20mm period, effective peak field of 1.05 Tesla, and 1800 mm magnetic length is being presented. The design requirements and mechanical difficulties for holding, positioning, and driving the magnetic arrays are explored. The structural and finite element analysis, magnetic design, and electrical considerations that influenced the design are then analyzed. This in-vacuum undulator (IVUN) is being installed at Pohang Accelerator Laboratory (PAL) for U-SAXS (Ultra Small Angle X-ray Scattering) beamline. The IVUN will generate undulator radiation up to ~14 keV using higher harmonic (upto 9th) undulator radiation with 2.5 GeV PLS electron beam.  
 
WEPD001 The Quality Control of the LHC Continuous Cryostat Interconnections controls, vacuum, induction, collider 2398
 
  • F. F. Bertinelli, D. Bozzini, P. Cruikshank, P. Fessia, W. Maan, A. Poncet, S. Russenschuck, F. Savary, Z. Sulek, J.-P. G. Tock, D. Tommasini, L. R. Williams
    CERN, Geneva
  • P. B. Borowiec, A. Kotarba, S. Olek
    HNINP, Kraków
  • A. Grimaud
    ALL43, Saint-Genis-Pouilly
  • L. Vaudaux
    IEG, St-Genis-Pouilly
  The interconnections between the Large Hadron Collider (LHC) magnets have required some 40 000 TIG welded joints and 65 000 electrical splices. At the level of single joints and splices, non-destructive techniques find limited application: quality control is based on the qualification of the process and of operators, on the recording of production parameters, and on production samples. Visual inspection and process audits were the main techniques used. At the level of an extended chain of joints and splices - from a 53.5 m half-cell to a complete 2.7 km sector - quality control is based on vacuum leak tests, electrical tests and RF microwave reflectometry that progressively validated the work performed. Subsequent sector pressure tests, cryogenic circuits flushing with high pressure helium and cool-downs revealed a few unseen or new defects. The nature of defects is analyzed and classified according to their origin. Methods for defect localization are described. This paper presents an overview of the quality control techniques used and critically evaluates their effectiveness in progressively identifying defects, seeking lessons applicable to similar large, complex projects.  
 
WEPD008 Automatic System for the DC High Voltage Qualification of the Superconducting Electrical Circuits of the LHC Machine controls, cryogenics, power-supply, dipole 2416
 
  • D. Bozzini, V. Chareyre, S. Russenschuck
    CERN, Geneva
  • M. Bednarek, P. Jurkiewicz, A. Kotarba, J. Ludwin, S. Olek
    HNINP, Kraków
  A system has been developed to verify automatically with the application of a DC high voltage, the insulation resistance between circuits to circuit and circuit to ground. In the most complex case of the LHC machine up to 72 circuits share the same volume inside the cryogenic lines and each circuit can have an insulation fault versus any other circuit or versus ground. The system can connect up to 80 circuits and apply a voltage up to 2 kV DC. The leakage of current flowing through each circuit is measured within a range of 1 nA to 2 mA. The matrix of measurements characterizes the paths taken by the currents and recognizes weak points of the insulation between circuits. The system is composed of a DC voltage source, a data acquisition card that measures with precision currents and voltages and drives up to 5 high voltage switching modules offering each 16 channels. A LabVIEW based application controls the system for an automatic and safe operation. This paper describes the hardware and software design, the testing methodology and the results obtained during the qualification of the LHC superconducting circuits.  
 
WEPD023 Multi-purpose Fiber Optic Sensors for HTS Magnets superconducting-magnet, optics, controls, background 2458
 
  • J. Schwartz
    NHMFL, Tallahassee, Florida
  • R. P. Johnson, S. A. Kahn, M. Kuchnir
    Muons, Inc, Batavia
  Magnets using new high temperature superconductor (HTS) materials are showing great promise for high magnetic field and/or radiation environment applications such as particle accelerators, NMR, and the plasma-confinement systems for fusion reactors. The development and operation of these magnets is limited, however, because appropriate sensors and diagnostic systems are not yet available to monitor the manufacturing and operational processes that dictate success. Optical fibers are being developed to be imbedded within the HTS magnets to monitor strain, temperature and irradiation, and to detect quenches. In the case of Bi2212, the fiber will be used as a heat treatment process monitor to ensure that the entire magnet has reached thermal equilibrium. Real-time measurements will aid the development of high-field magnets that are subject to large Lorentz forces and allow the effective detection of quenches so that the stored energy of operating magnets can be extracted and/or dissipated without damaging the magnet.  
 
WEPD038 Thermal and Structural Modeling of the TTF Cryomodule Cooldown and Comparison with Experimental Data simulation, cryogenics, radiation, controls 2494
 
  • S. Barbanotti, P. Pierini
    INFN/LASA, Segrate (MI)
  • K. Jensch, R. Lange, W. Maschmann
    DESY, Hamburg
  The study of thermal and structural behavior during cooldown/warmup of long SRF cryostats is important for both the XFEL and ILC, which base the design on the successful TTF design. We present the finite elements analysis of the main internal components of the cryomodules during the transient cooldown and warmup, comparing the data obtained with data taken at DESY on the linac.  
 
WEPP056 Aperture Restriction Localisation in the LHC Arcs using an RF Mole and the LHC Beam Position Measurement System vacuum, dipole, radio-frequency, quadrupole 2644
 
  • O. R. Jones, J. Albertone, S. Bartolome-Jimenez, C. Boccard, T. Bogey, P. B. Borowiec, E. Calvo, F. Caspers, M. Gasior, J. L. Gonzalez, B. Jenninger, L. K. Jensen, T. Kroyer, S. Weisz
    CERN, Geneva
  Ensuring that the two 27km beam pipes of the LHC do not contain aperture restrictions is of utmost importance. Most of the ring is composed of continuous cryostats, so any intervention to remove aperture restrictions when the machine is at its operating temperature of 1.9K will require a substantial amount of time. On warming-up the first cooled sector, several of the sliding contacts which provide electrical continuity for the image current between successive sections of the vacuum chamber were found to have buckled into the beam pipe. This led to a search for a technique to verify the integrity of a complete LHC arc (~3km) before any subsequent cool-down. In this paper the successful results from using a polycarbonate ball fitted with a 40MHz RF transmitter will be presented. Propulsion of the ball is achieved by sucking filtered air through the entire arc, while its progress is traced every 54m via the LHC beam position measurement system which is auto-triggered by the RF transmitter on passage of the ball. Reflectometry at frequencies in the 4-8 GHz range can cover the gaps between beam position monitors and could therefore be used to localise a ball blocked by an obstacle.  
 
WEPP148 Generation of High Gradient Wakefields in Dielectric Loaded Structures electron, gun, laser, insertion 2835
 
  • M. E. Conde, S. P. Antipov, F. J. Franchini, W. Gai, F. Gao, R. Konecny, W. Liu, J. G. Power, Z. M. Yusof
    ANL, Argonne, Illinois
  • C.-J. Jing
    Euclid TechLabs, LLC, Solon, Ohio
  Dielectric loaded wakefield structures have potential to be used as high gradient accelerator components. Using the high current drive beam at the Argonne Wakefield Accelerator Facility, we employed cylindrical dielectric loaded wakefield structures to generate accelerating fields of up to 100 MV/m. Short electron bunches (13 ps FWHM) of up to 86 nC are used to drive these fields, either as single bunches or as bunch trains. These recently tested standing-wave structures have a field probe near the outer edge of the dielectric to sample the RF fields generated by the electron bunches. Monitoring of these high intensity RF fields serves to verify the absence of electric breakdown.  
 
THPC150 The Use of Software in Safety Critical Interlock Systems of the LHC superconducting-magnet, proton, diagnostics 3342
 
  • A. Castaneda, F. B. Bernard, P. Dahlen, I. Romera, B. Todd, D. Willeman, M. Zerlauth
    CERN, Geneva
  This paper will provide an overview of the software development and management techniques applied to interlock systems in the CERN accelerator complex. Despite the in essence hardware based approach, software and configuration data is present in various forms and has to be treated with special care when aiming at safe, reliable and available protection systems. Several techniques and methods deployed in the LHC machine protection systems are highlighted, regarding data management and version tracking, hardware choices, commissioning procedures, testing methods and first operational experiences with the systems in CERN's accelerator complex.  
 
THPP072 Extinction Monitor by Using a Dissociation of Hydrogen Molecule to Atoms with High Energy Proton Beam proton, ion, electron, ion-source 3527
 
  • I. Itahashi, M. Aoki, Y. Arimoto, Y. Kuno, A. Sato, M. Y. Yoshida
    Osaka University, Osaka
  In a recent high current accelerator technology there are so many reasons for resulting in unwanted or hallow beam to be coped with, such as resonance crossing, space charge induced emittance growth and so on. For an extinction for bunched beam of less than 10-7 order we need a particular scheme to diminish unwanted and hallow beam generated at not only spatial plane but also at longitudinal plane. In particular, the beam extinction between beam bunch is crucial for delayed coincidence measurements of intensity frontier and high sensitivity experiment such as muon to electron conversion and muon to electron gamma. The new detection method for the extinction is proposed by using a collision dissociation between a high energy proton with more than GeV energy and molecular ions. One path collision of high energy beam for molecular ion beam to be separated into atoms as well as its collision between stored molecular ions and high energy particles could be exploited for the monitor.  
 
THPP127 ATF2 High Availability Power Supplies power-supply, controls, diagnostics, beam-losses 3658
 
  • B. Lam, P. Bellomo, D. J. MacNair, G. R. White, A. C. de Lira
    SLAC, Menlo Park, California
  • V. R. Rossi
    O. C.E. M. S.p. A., S. Giorgio di Piano
  ATF2 is an accelerator test facility modeled after the final focus beamline envisioned for the ILC. By the end of 2008, KEK plans to commission the ATF2. SLAC and OCEM collaborated on the design of 38 power systems for beamline magnets. The systems range in output power from 1.5 kW to 6 kW. Since high availability is essential for the success of the ILC, Collaborators employed an N+1 modular approach, allowing for redundancy and the use of a single power module rating. This approach increases the availability of the power systems. Common power modules reduces inventory and eases maintenance. Current stability requirements are as tight as 10 ppm. A novel, SLAC-designed 20-bit Ethernet Power Supply Controller provides the required precision current regulation. In this paper, Collaborators present the power system design, the expected reliability, fault immunity features, and the methods for satisfying the control and monitoring challenges. Presented are test results and the status of the power systems.  
 
THPP146 High-voltage Power Supply Distribution System vacuum, ion, controls, storage-ring 3708
 
  • M. Kobal, D. Golob, M. Plesko, A. Podborsek
    Cosylab, Ljubljana
  • T. Kusterle, M. Pelko
    JSI, Ljubljana
  High-voltage splitters enable connecting a larger number of ion-pumps to a single ion-pump controller. In particle accelerator facilities where relatively small pumps are used, using high-voltage splitters can significantly reduce costs and rack space. By using simple high-voltage splitters some functionality of the conrollers can be lost. The presented high-volage splitter is one of the most advanced devices on the market. It measures current going to every pump in the range 100 pA to 100 mA with an accuracy of 5%. Fully configurable tables are used to convert the measured current to the pressure at the pump. Current measurements are also used to monitor cable and ion-pump aging which results in linear increase of current with time. Hardware interlocks are used to disconnect individual pumps in case of poor vacuum to avoid pump damage. The limits can be set by the user, who can also set the number of active pumps. EPICS support was developed for the device with graphical user interfaces writen in EDM, java and WebCA. Since the presented device covers or exceeds a lot of the ion-pump controller functionality, simpler controlers can be used.  
 
THPP150 LANSCE Vacuum System Refurbishment Plan and Vacuum Alert System Improvements for Predictive Maintenance vacuum, ion, linac, power-supply 3717
 
  • T. Tajima, M. J. Borden, A. Canabal, J. P. Chamberlin, S. Harrison, F. R. Olivas, M. A. Oothoudt
    LANL, Los Alamos, New Mexico
  The Los Alamos Neutron Science Center (LANSCE) accelerator, an 800-MeV H+/H- LINAC with a storage ring, has been operated over 30 years since early 1970s. A refurbishment project named LANSCE-R was approved and started in 2007. This paper describes our plan for vacuum system refurbishment as well as an update on the ongoing vacuum email alert system improvement project, which will eventually notify workers of the need for predictive maintenance of particular devices like ion pumps.