Keyword: diagnostics
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MOOBN5 Maximizing Technology Transfer Benefits to Society ion, instrumentation, feedback, background 7
 
  • A. Peters
    HIT, Heidelberg, Germany
  
  What is ‘technology transfer’? Is it just the movement of knowledge or is it a more interactive process? The speaker will present definitions of technology transfer and discuss the linked challenges. Furthermore some technology trans¬fer examples from industry will be given to derive step by step feasible strategies for successful collaboration. Problems like ‘different cultures’ in science institutes and industry will also be discussed as well as other key factors, e.g. the ability and willingness of scientists to move from public institutes to industry.  
slides icon Slides MOOBN5 [7.165 MB]  
 
MOOBS3 Bunch-End Interpenetration During Evolution to Longitudinal Uniformity in a Space-Charge-Dominated Storage Ring simulation, space-charge, electron, longitudinal-dynamics 22
 
  • T.W. Koeth, B.L. Beaudoin, S. Bernal, I. Haber, R.A. Kishek, P.G. O'Shea
    UMD, College Park, Maryland, USA
  
  The University of Maryland Electron Ring is a facility for study of the novel physics that occurs as intense space-charge-dominated beams that are transported over long distances. An example presented here is the role of space-charge longitudinal expansion and bunch-end interpenetration in the relaxation of a coasting bunch towards uniformly filling the ring. By comparing experiment to simplified longitudinal simulations the relaxation process is shown to be largely independent of details of the transverse dynamics. However, to get detailed agreement it was found necessary to include the consequences of transverse current loss. Since the AC coupled diagnostics lose information on any DC current loss, a novel beam knockout technique was developed to recover this information.  
slides icon Slides MOOBS3 [2.501 MB]  
 
MOP141 Design, Fabrication and Characterization of a Micron-scale Electron Source Based on Field Enhanced Pyroelectric Crystals electron, laser, simulation, polarization 352
 
  • H. Badakov, J.M. Allen, N.S. Carranza, G. Travish, J. Zhou
    UCLA, Los Angeles, California, USA
  • E.R. Arab
    PBPL, Los Angeles, USA
  • R.B. Yoder
    Manhattanville College, Purchase, New York, USA
  
  As a part of the Micro-Accelerator Platform (MAP) project, an electron source with a sub-micron size emitter is required. It is also desired that the source produces electrons with energies above the structure's minimum capture energy (about 25 keV) without the use of an external power supply. Field enhanced emission backed by field generation in pyroelectric crystals has been explored for this application. Here we present experimental progress towards characterization of electron, and x-ray emission. Purpose built diagnostics and specialized test assembly for optimized heat transmission are discussed.  
 
MOP169 Optical Beam Diagnostics at ELSA emittance, synchrotron, quadrupole, sextupole 408
 
  • S. Zander, F. Frommberger, P. Haenisch, W. Hillert, S. Patzelt
    ELSA, Bonn, Germany
  
  Funding: Funded by the DFG within the SFB / TR 16.
The Electron Stretcher Facility ELSA consists of several accelerator stages, the last one being a storage ring providing a beam of polarized electrons of up to 3.5 GeV. At ELSA various diagnostic devices based on synchrotron radiation are installed or planned. A new beamline at the storage ring designed for high resolution diagnostics in the transversal plane will be presented. The measurement setup is sensitive at the UV range of the synchrotron light spectrum. Upgrade measures aiming to extend the diagnostic possibilities to the longitudinal direction will be detailed. In the external beamlines beam currents below 1 nA are delivered to photo production experiments. Beam profiles are detected using dedicated synchrotron light monitors optimized for low intensities. The characteristics of the monitors will be described. In addition, beam parameters derived from the measured profiles at different resonance extraction setups will be shown. 		 
 
MOP176 Design of Cavity Beam Quadrupole Moment Monitor at HLS quadrupole, cavity, emittance, electron 417
 
  • Q. Luo, Q.K. Jia, B.G. Sun, Z.R. Zhou
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  Funding: Work supported by the Natural Science Foundation of China, National “985 Project”, China Postdoctoral Science Foundation and “the Fundamental Research Funds for the Central Universities”
Traditional ways to get beam emittance of linacs, such as multi-slits method, are destructive and then not able to be used in on-line beam diagnostics. To meet the requirements of XFEL equipments and improve the quality of electron beam, non-destructive on-line beam emittance measurement methods basing on getting the quadrupole moment of a beam non-destructively are then required. An advanced way to pick up beam information non-destructively with great precision is making use of eigenmodes of resonant cavities. High brightness injector at Hefei light source is used to study FEL based on photocathode RF electron gun. Cavity beam quadrupole moment monitor system designed for the high brightness injector consists of a square pill-box cavity used to pick up quadrupole signal, a cylindrical pill-box reference cavity, a waveguide coupling network that can suppress monopole and dipole signal, and a superheterodyne receiver used as front-end signal processing system. The whole system works at 5.712 GHz. Strength of quadupole magnets is adjust to construct a matrix which can be used to work out beam parameters. 		 
 
MOP184 Beam Instrumentation for the European Spallation Source linac, cryomodule, target, rfq 432
 
  • A. Jansson, H. Danared, M. Eshraqi, L. Tchelidze
    ESS, Lund, Sweden
  
  The European Spallation Source, which will be built in the south of Sweden, is a neutron source based on a 5MW, 2.5GeV proton linac. The project is currently in the design update phase, and will deliver a Technical Design Report at the end of 2012. Construction is expected to begin in 2013. This paper discusses the initial beam diagnostics specifications, along with some possible instrument design options.  
 
MOP185 Development of Longitudinal Beam Profile Diagnostics within DITANET target, electron, radiation, ion 435
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  Funding: Work supported by the EU under contract PITN-GA-2008-215080.
The exact determination of the time structure of ever shorter bunches in accelerators and light sources such as for example the X-FEL, the ILC or CLIC is of high importance for the successful operation of these next-generation machines. It is also a key to the optimization of existing scientific infrastructures. The exact measurement of the time structure poses a number of challenges to the beam diagnostics system: The monitors should be non-destructive, easy to maintain and provide time resolutions down to the femtosecond regime. Several DITANET partners are active in this field. This contribution gives examples of the network’s research activities in this area with a focus on the LHC longitudinal density monitor, beam profile monitoring using electro-optics techniques and the exploitation of diffraction radiation for non-invasive diagnostics. 		 
 
MOP186 Low Energy Beam Diagnostics Developments within DITANET storage-ring, ion, instrumentation, target 438
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  Funding: Work supported by the EU under contract PITN-GA-2008-215080.
Low energetic ion beam are very attractive for a large number of fundamental physics experiments. The development of beam instrumentation for such beams poses many challenges due to the very low currents down to only a few thousands of particles per second and the resulting very low signal levels. Within DITANET, several institutions aim at pushing low energy, low intensity diagnostics beyond the present state-of-the-art. This contribution gives examples from the progress across the DITANET network in this research area.
On behalf of the DITANET consortium. 		 
 
MOP193 Design of Visible Diagnostic Beamline for NSLS2 Storage Ring radiation, synchrotron, electron, storage-ring 453
 
  • W.X. Cheng, H.C. Fernandes, H.-C. Hseuh, B.N. Kosciuk, S. Krinsky, O. Singh
    BNL, Upton, Long Island, New York, USA
  
  A visible synchrotron light monitor (SLM) beam line has been designed at the NSLS2 storage ring, using the bending magnet radiation. A retractable thin absorber will be placed in front of the first mirror to block the central x-rays. The first mirror will reflect the visible light through a vacuum window. The light is guided by three 6" diameter mirrors into the experiment hutch. In this paper, we will describe design work on various optical components in the beamline.  
 
MOP198 BPM Inputs to Physics Applications at NSLS-II feedback, controls, EPICS, alignment 465
 
  • Y. Hu, L.R. Dalesio, J.H. DeLong, K. Ha, J. Mead, I. Pinayev, G. Shen, O. Singh, Y. Tian, K. Vetter, L.-H. Yu
    BNL, Upton, Long Island, New York, USA
  
  A new BPM (Beam Position Monitor) electronics is under development and in good progress at NSLS-II. This in-house BPM receiver with many new features is comparable to commercial solution. BPM data for fast orbit feedback (FOFB) is one of the most important physics applications. The procedure to use BPM for FOFB is introduced firstly. Then, different BPM data flows associated with different physics requirements and applications are discussed. And control implementation of BPM system for physics applications is presented.  
 
MOP199 NSLS-II X-ray Diagnostics Development optics, radiation, electron, wiggler 468
 
  • P. Ilinski
    BNL, Upton, Long Island, New York, USA
  
  NSLS-II storage ring will have less then 1nm*rad emittance. A concept of X-ray diagnostics beamline was developed in order to measure small sizes of radiation sources to deduct beam emittance. Diagnostics will include pinhole cameras and Compound Refractive Lens focusing optics. A novel optical layout was suggested in order to measure sources with large horizontal to vertical aspect ratio.  
 
MOP205 NSLS-II Injection Straight Diagnostics injection, vacuum, septum, kicker 477
 
  • I. Pinayev, A. Blednykh, M.J. Ferreira, R.P. Fliller, B.N. Kosciuk, T.V. Shaftan, G.M. Wang
    BNL, Upton, Long Island, New York, USA
  
  The ultra-bright light source being developed by the NSLS-II project will utilize top-up injection and fine tuning of the injection process is mandatory. In the paper we present the diagnostics installed on the injection straight. Its usage for commissioning and tuning of the injection cycle is also described.  
 
MOP207 Diamond X-ray Beam Position Monitors monitoring, undulator, photon, insertion 483
 
  • J. Smedley, A. Heroux, J.W. Keister
    BNL, Upton, Long Island, New York, USA
  • K. Attenkofer
    ANL, Argonne, USA
  • J. Bohon
    Case Western Reserve University, Center for Synchrotron Biosciences, Upton, New York, USA
  • J. Distel
    LANL, Los Alamos, New Mexico, USA
  • M. Gaowei
    SBU, Stony Brook, New York, USA
  • E.M. Muller
    Stony Brook University, Stony Brook, USA
  
  Funding: The authors wish to acknowledge the support of the U.S. Department of Energy (DOE) under grant DE-FG02-08ER41547.
Modern synchrotrons are capable of significant per-pulse x-ray flux, and time resolved pulse-probe experiments have become feasible. These experiments provide unique demands on x-ray monitors, as the beam position, flux and arrival time all potentially need to be recorded for each x-ray pulse. Further, monitoring of “white” x-ray beam position and flux upstream of beamline optics is desirable as a diagnostic of the electron source. We report on a diamond quadrant monitors which provide beam monitoring for a variety of applications, for both white and monochromatic beams. These monitors have a position resolution of 20 nm for a stable beam, are linear in flux over at least 11 orders of magnitude, and can resolve beam motion shot-by-shot at repetition rates up to 6.5 MHz. 		 
 
MOP209 Proposed Scattered Electron Detector System as One of the Beam Overlap Diagnostic Tools for the New RHIC Electron Lens electron, proton, scattering, solenoid 489
 
  • P. Thieberger, E.N. Beebe, C. Chasman, W. Fischer, D.M. Gassner, X. Gu, R.C. Gupta, J. Hock, R.F. Lambiase, Y. Luo, M.G. Minty, C. Montag, M. Okamura, A.I. Pikin, Y. Tan, J.E. Tuozzolo, W. Zhang
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An electron lens for head-on beam-beam compensation planned for RHIC requires precise overlap of the electron and proton beams which both can have down to 0.3 mm rms transverse radial widths along the 2m long interaction region. Here we describe a new diagnostic tool that is being considered to aid in the tuning and verification of this overlap. Some of ultra relativistic protons (100 or 250 GeV) colliding with low energy electrons (2 to 10 keV) will transfer sufficient transverse momentum to cause the electrons to spiral around the magnetic guiding field in a way that will make them detectable outside of the main solenoid. Time-of-flight of the halo electron signals will provide position-sensitive information along the overlap region. Scattering cross sections are calculated and counting rate estimates are presented as function of electron energy and detector position. 		 
 
MOP219 Initial Beam-Profiling Tests with the NML Prototype Station at the Fermilab A0 Photoinjector radiation, emittance, optics, target 510
 
  • A.H. Lumpkin, M.D. Church, R.H. Flora, A.S. Johnson, J. Ruan, J.K. Santucci, V.E. Scarpine, Y.-E. Sun, R.M. Thurman-Keup, M. Wendt
    Fermilab, Batavia, USA
  
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Beam-profile diagnostics are being developed for a superconducting (SC) radiofrequency (RF) Test Accelerator that is currently under construction at the New Muon Lab (NML) at Fermilab. The facility’s design goals include the replication of the pulse train proscribed for the International Linear Collider (ILC). An RF photoelectric gun based on the DESY design will generate the beam. In test-beam mode a low-power beam will be characterized with intercepting radiation converter screens: either a 100-micron thick YAG:Ce single crystal scintillator or a 1-micron thin Al optical transition radiation (OTR) foil. This prototype station was constructed by RadiaBeam Technologies under a contract with Fermilab. In both cases the screen surface was normal to the beam direction followed by a downstream 45-degree mirror that directed the radiation into the optical system. The optical system has better than 20 (10) micron rms spatial resolution when covering a vertical field of view of 18(5) mm. These initial tests were performed at the A0 Photoinjector at a beam energy of ~15 MeV and with micropulse charges from 25 to 500 pC for beam sizes of 45 to 250 microns. Example results will be presented.

 
 
MOP230 Precise Charge Measurement for Laser Plasma Accelerators electron, laser, plasma, target 537
 
  • K. Nakamura, W.E. Byrne, R.J. Donahue, A.J. Gonsalves, C. Lin, J. Osterhoff, D.E. Rodgers, A.R. Smith, T. Sokollik, J. van Tilborg
    LBNL, Berkeley, California, USA
  • W. Leemans
    UCB, Berkeley, California, USA
  • S. Shiraishi
    Enrico Fermi Institute, University of Chicago, Chicago, Illinois, USA
  
  Funding: Work supported by the Office of Science, Office of High Energy Physics, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Cross-calibrations of charge diagnostics are conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). Employed diagnostics are a scintillating screen, activation based mea- surement, and integrating current transformer. The diagnostics agreed within ±8 %, showing that they can provide accurate charge measurements for LPAs provided they are used properly. 		 
 
MOP233 LANSCE-R Wire-scanner System controls, EPICS 545
 
  • M.E. Gruchalla
    URS, Albuquerque, New Mexico, USA
  • P. Chacon, J.D. Gilpatrick, D. Martinez, S. Rodriguez Esparza, F.D. Sattler, J.D. Sedillo, B.G. Smith
    LANL, Los Alamos, New Mexico, USA
  
  Funding: US Department of Energy
The National Instruments cRIO platform is used for the new LANSCE-R wire-scanner systems. All wire-scanner electronics are integrated into a single BiRa BiRIO 4U cRIO chassis specifically designed for the cRIO crate and all interface electronics. The BiRIO chassis, actuator and LabVIEW VIs provide a complete wire-scanner system integrated with EPICS. The new wire-scanner chassis includes an 8-slot cRIO crate with Virtex-5 LX 110 FPGA and Power-PC real-time controller, the LANL-developed cRIO 2-axis wire-sensor analog interface module (AFE), NI9222 cRIO 4-channel 16-bit digitizer, cRIO resolver demodulator, cRIO event receiver, front-panel touch panel display, motor driver, and all necessary software, interface wiring, connectors and ancillary components. This wire-scanner system provides a complete, turn-key, 2-axis wire-scanner system including 2-channel low-noise sense-wire interface with variable DC wire bias and wire-integrity monitor, 16-bit signal digitizers, actuator motor drive and control, actuator position sensing, limit-switch interfaces, event receiver, LabVIEW and EPICS interface, and both remote operation and full stand-alone operation using the touch panel. 		 
 
MOP235 LANSCE Wire Scanning Diagnostics Device Prototype vacuum, linac, proton, acceleration 551
 
  • S. Rodriguez Esparza, Y.K. Batygin, J.D. Gilpatrick, M.E. Gruchalla, A.J. Maestas, C. Pillai, J.L. Raybun, F.D. Sattler, J.D. Sedillo, B.G. Smith
    LANL, Los Alamos, New Mexico, USA
  
  The Accelerator Operations & Technology Division at Los Alamos National Laboratory operates a linear particle accelerator which utilizes 110 wire scanning diagnostics devices to gain position and intensity information of the proton beam. In the upcoming LANSCE improvements, 51 of these wire scanners are to be replaced with a new design, up-to-date technology and off-the-shelf components. This document outlines the requirements for the mechanical design of the LANSCE wire scanner and presents the recently developed linac wire scanner prototype. Additionally, this document presents the design modifications that have been implemented into the fabrication and assembly of this first linac wire scanner prototype. Also, this document will present the design for the second and third wire scanner prototypes being developed. These last two prototypes belong to a different section of the particle accelerator and therefore have slightly different design specifications. Lastly, the paper concludes with a plan for future work on the wire scanner development.  
 
MOP236 First Test Results of the New LANSCE Wire Scanner controls, background, coupling, target 554
 
  • J.D. Sedillo, J.D. Gilpatrick, F. Gonzales, V. Kutac, D. Martinez
    LANL, Los Alamos, New Mexico, USA
  • M.E. Gruchalla
    URS, Albuquerque, New Mexico, USA
  
  Funding: United States Department of Energy.
The Beam Diagnostics and Instrumentation Team at Los Alamos National Laboratory’s LANSCE facility is presently developing a new and improved wire scanner diagnostics system controlled by National Instrument’s cRIO platform. This report describes the current state of development of the control system along with the results gathered from the latest actuator motion performance and accelerator beam data acquisition tests. 		 
 
MOP239 Commercially Available Transverse Profile Monitors, the IBIS target, vacuum, optics, impedance 562
 
  • M. Ruelas, R.B. Agustsson, I. Bacchus, A.Y. Murokh, R. Tikhoplav
    RadiaBeam, Santa Monica, USA
  
  With ever decreasing budgets, shorter delivery schedules and increased performance requirements for pending and future facilities, the need for cost effective yet high quality profile monitors is paramount to future advancement in the accelerator field. While individual facilities are capable of designing and fabricating these often custom devices, this is not always the most efficient or economical route. In response to the lack of commercially available profile monitors, RadiaBeam Technologies has been developing its line of Integrated Beam Imaging System (IBIS) over the past several years. Here, we report on these commercially available profile monitors.  
 
MOP241 Beam Diagnostics for FACET plasma, radiation, electron, linac 565
 
  • S.Z. Li, M.J. Hogan
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515.
FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23 GeV, 3 nC electron bunches compressed to ~20 μm long and focussed to ~10 μm wide. Characterization of the beam- plasma interaction requires complete knowledge of the incoming beam parameters on a pulse-to- pulse basis. FACET diagnostics include Beam Position Monitors, Toroidal current monitors, X-ray and Cerenkov based energy spectrometers, optical transition radiation (OTR) profile monitors and coherent transition radiation (CTR) bunch length measurement systems. The compliment of beam diagnostics and their expected performance are reviewed. 		 
 
MOP242 Evaluation of Temporal Diagnostic Techniques for Two-bunch FACET Beam laser, plasma, cavity, wakefield 568
 
  • M.D. Litos, M.R. Bionta, V.A. Dolgashev, R.J. England, D. Fritz, A. Gilevich, P. Hering, M.J. Hogan
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515
Three temporal diagnostic techniques are considered for use in the FACET facility at SLAC, which will incorporate a unique two-bunch beam for plasma wakefield acceleration experiments. The results of these experiments will depend strongly on the the inter-bunch spacing as well as the longitudinal profiles of the two bunches. A reliable, single-shot, high resolution measurement of the beam’s temporal profile is necessary to fully quantify the physical mechanisms underlying the beam driven plasma wakefield acceleration. In this study we show that a transverse deflecting cavity is the diagnostic which best meets our criteria. 		 
 
MOP249 Improved Alarm Tracking for Better Accountability controls, feedback, status, collider 579
 
  • S. Nemesure, T. D'Ottavio, L.R. Hammons, P.F. Ingrassia, N.A. Kling, G.J. Marr, T.C. Shrey
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An alarm system is a vital component of any accelerator, as it provides a warning that some element of the system is not functioning properly. The severity and age of the alarm may sometimes signify whether urgent or deferred attention is required. For example, older alarms may inadvertently be given a lower priority if an assumption is made that someone else is already investigating it, whereas those that are more current may indicate the need for an immediate response. The alarm history also provides valuable information regarding the functionality of the overall system, thus careful tracking of these data is likely to improve response time and remove uncertainty about the current status. Since one goal of every alarm display is to be free of alarms, a clear and concise presentation of an alarm along with useful historic annotations can help the end user address the warning more quickly. By defining a discrete set of very specific alarm states and by utilizing database resources to maintain a complete and easily accessible alarm history, we anticipate a decrease in down time due to more efficient operator response and management of alarms. 		 
 
MOP278 Ultra Precision Timing System for the Laser Megajoule laser, high-voltage, target, plasma 633
 
  • V. Drouet, M. Luttmann, M. Prat
    CEA, Arpajon, France
  
  This article presents a specific timing system designed for the Laser Megajoule project. This accuracy timing system has to deliver 64 electrical trigger signals with a very low jitter (< 5 ps rms) in order to synchronize the 240 laser pulses on the same target, in single shot mode and over 100 meter distances. After a dimensioning phase leading to the architecture of the system and the selection of components, a prototype was developed providing 8 electrical trigger signals. We expose the architecture and the excellent results achieved on this prototype regarding jitter, thermal drift and delay linearity.  
 
MOP282 A Deterministic, Gigabit Serial Timing, Synchronization and Data Link for the RHIC LLRF LLRF, controls, site, target 642
 
  • T. Hayes, F. Severino, K.S. Smith
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A critical capability of the new RHIC low level rf system is the ability to synchronize signals across multiple locations. The Update Link provides this functionality. The Update Link is a deterministic serial data link based on the Xilinx Aurora protocol that is broadcast over fiber optic cable at 1 gigabit per second. The link provides timing events and data packets as well as time stamp information for synchronizing diagnostic data from multiple sources. 		 
 
MOP285 Synchronization and Jitter Studies of a Titanium-sapphire Laser at the A0 Photoinjector laser, gun, feedback, cathode 651
 
  • T.J. Maxwell, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • M.J. Kucera, J. Ruan
    Fermilab, Batavia, USA
  
  Funding: Supported by Fermi Research Alliance, LLC under U.S. Dept. of Energy Contract No. DE-AC02-07CH11359, and Northern Illinois Univ. under US Dept. of Defense DURIP program Contract N00014-08-1-1064.
A new titanium-sapphire laser has recently been installed at the A0 photoinjector for use in ongoing beam generation and ultra-fast beam diagnostics experiments. Where the system is used as the photoinjector drive laser, jitter and drift in the laser pulse time of arrival with respect to the low-level RF master oscillator and other beam components are known to degrade beam performance. These same fluctuations can also impact the temporal resolution of laser-based diagnostics. To resolve this, we present the results of some beam-based timing experiments as well as current progress on a synchronization feedback loop being adapted to the new laser system. 		 
 
TUP101 Plasma Treatment of Single-Cell Niobium SRF Cavities plasma, cavity, SRF, power-supply 1027
 
  • J. Upadhyay, M. Nikolić, S. Popović, L. Vušković
    ODU, Norfolk, Virginia, USA
  • H.L. Phillips, A-M. Valente-Feliciano
    JLAB, Newport News, Virginia, USA
  
  In our previous work, we have demonstrated on flat sam- ples that plasma etching in Ar/Cl2 of bulk Nb is a viable alternative surface preparation technique to BCP and EP methods, with comparable etching rates. Here we report on the progress in experimental design for plasma processing of a single cell SRF cavity. The experiments are centered on two discharge types - asymmetric RF and low mode mi- crowave cavity discharge. We report on the experimental design of the setup with a specially designed single cell cavity with sample holders, and discuss the diagnostics of plasma and samples. We provide preliminary results on the RF discharge in the single cell that is to be the main part of the optimized experiment.  
 
TUP193 NSLS-II Power Supply Controller power-supply, controls, booster, storage-ring 1187
 
  • W. Louie, L.R. Dalesio, G. Ganetis, Y. Tian
    BNL, Upton, Long Island, New York, USA
  
  This paper presents the design of the National Synchrotron Light Source II (NSLS-II) Power Supply Controller (PSC). It consists of a main board, rear module and backplane. The main features of NSLS-II PSC included 256MB DDR2 memory for power supply system diagnostics, high speed serial link between PSC modules, an embedded microprocessor and a 100 Mbps Ethernet port. Each PSC module can be remotely programmed through network. NSLS-II PSC will be used to control power supplies in Storage Ring, Booster Ring and Transport line. The PSC also provides interface for the NSLS-II fast and slow orbits feedback system.  
 
TUP229 Implementation and Operation of Electron Cloud Diagnostics for CesrTA vacuum, electron, pick-up, quadrupole 1250
 
  • Y. Li, J.V. Conway, X. Liu, V. Medjidzade, M.A. Palmer
    CLASSE, Ithaca, New York, USA
  
  Funding: Work Supported by NSF Grant #PHY-0734867 & DOE Grant #DE-FC02-08ER41538
The vacuum system of Cornell Electron Storage Ring (CESR) was successfully reconfigured to support CesrTA physics programs, including electron cloud (EC) build-up and suppression studies. One of key features of the reconfigured CESR vacuum system is the flexibility for exchange of various vacuum chambers with minimized impact to the accelerator operations. This is achieved by creation of three short gate-valve isolated vacuum sections. Over the last three years, many vacuum chambers with various EC diagnostics (such as RFAs, shielded pickups, etc) were rotated through these short experimental sections. With these instrumented test chambers, EC build-up was studied in many magnetic field types, including dipoles, quadrupoles, wigglers and field-free drifts. EC suppression techniques by coating (TiN, NEG and amorphous-C), surface textures (grooves) and clearing electrode are incorporated in these test chambers to evaluate their vacuum performance and EC suppression effectiveness. We present the implementation and operations of EC diagnostics. 		 
 
TUP283 Inductively Coupled, Compact HOM Damper for the Advanced Photon Source impedance, HOM, coupling, damping 1358
 
  • G.J. Waldschmidt, D. Horan, L.H. Morrison
    ANL, Argonne, USA
  
  Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357
The Advanced Photon Source requires damping of higher-order modes in the storage ring rf cavities in order to prevent beam instability at beam currents in excess of 100 mA proposed for the APS Upgrade. Due to constraints imposed by available space and by existing 35-mm pick-up ports on the cavity, a compact design has been analyzed with a quarter-wave rejection filter of the fundamental mode. Separate broadband, low-frequency and high-frequency dampers are utilized to span the frequency range from 500 MHz to 1500 MHz. The dampers have been designed to reject the fundamental cavity mode, couple strongly to HOM’s, utilize an external rf load, minimize the overall size, and incorporate rf diagnostics. In addition, the mechanical design has been optimized to simplify construction, improve mechanical stability, and reduce thermally induced stresses. 		 
 
WEOBN2 Real-Time Beam Control at the LHC feedback, controls, coupling, dipole 1399
 
  • R.J. Steinhagen
    CERN, Geneva, Switzerland
  
  At the LHC, real-time feedback systems continually control the orbit, tune, coupling, and chromaticity. Reliable and precise control of these parameters is essential to avoid superconducting magnet quenches or damage to LHC components. The speaker will review the underlying principles and hardware, and describe experiences with these systems during LHC commissioning and operations.  
slides icon Slides WEOBN2 [5.475 MB]  
 
WEOBS1 The Berkeley Lab Laser Accelerator (BELLA): A 10 GeV Laser Plasma Accelerator laser, plasma, electron, simulation 1416
 
  • W. Leemans, R.M. Duarte, E. Esarey, D.S. Fournier, C.G.R. Geddes, D. Lockhart, C.B. Schroeder, C. Tóth, J.-L. Vay, S. Zimmermann
    LBNL, Berkeley, California, USA
  
  An overview is presented of the design of a 10 GeV laser plasma accelerator (LPA) that will be driven by a PW-class laser system and of the BELLA Project, under which the required Ti:sapphire laser system for the acceleration experiments is being installed. The basic design of the 10 GeV stage aims at operation in the quasi-linear regime, where the laser excited wakes are largely sinusoidal and allow acceleration of electrons and positrons. Simulations show that a 10 GeV electron beam can be generated in a meter scale plasma channel guided LPA operating at a density of about 1017 cm-3 and powered by laser pulses containing 30-40 J of energy in a 50-200 fs duration pulse, focused to a spotsize of 50-100 micron. The lay-out of the facility and laser system will be presented as well as the progress on building the facility.  
 
WEOCN1 Laser Based Diagnostics for Measuring H- Beam Parameters laser, ion, emittance, linac 1433
 
  • Y. Liu, A.V. Aleksandrov, W. Blokland, C. Deibele, C.D. Long, A.A. Menshov, J. Pogge, A. Webster, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
  • R.A. Hardin
    ORNL RAD, Oak Ridge, Tennessee, USA
  
  Funding: sponsored by the Division of Materials Science, U.S. Department of Energy, under contract number DE-AC05-96OR22464 with UT-Battelle Corporation for Oak Ridge National Laboratory
In recent years, a number of laser based H- beam diagnostics systems have been developed in the Spallation Neutron Source (SNS). This talk reviews three types of laser based diagnostics at SNS: the laser wire profile monitors at superconducting linac (SCL), the laser transverse emittance scanner at high energy beam transport (HEBT), and the laser bunch shape monitor at medium energy beam transport (MEBT). Measurement performance will be reported and major technical challenges in the design, implementation, and operation of laser based diagnostics at accelerator facilities will be addressed. 		 
slides icon Slides WEOCN1 [4.710 MB]  
 
WEP024 Near-ideal Emittance Exchange at the Fermilab Photoinjector emittance, cavity, electron, coupling 1543
 
  • A.S. Johnson, H.T. Edwards, A.H. Lumpkin, J. Ruan, J.K. Santucci, R.M. Thurman-Keup
    Fermilab, Batavia, USA
  
  The A0 Photoinjector at Fermilab is presently home to an emittance exchange (EEX) experiment. The emittance exchange beamline consists of a 3.9 GHz normal conducting deflecting mode cavity flanked by two doglegs. Electron bunches with charges of 250 pC and energy of 14.3 MeV are routinely sent through the exchanger. Here we present results of a 1:1 transverse and longitudinal emittance exchange.  
 
WEP162 Modeling of Diamond Based Devices for Beam Diagnostics electron, photon, simulation, scattering 1794
 
  • D.A. Dimitrov, R. Busby
    Tech-X, Boulder, Colorado, USA
  • I. Ben-Zvi, J.W. Keister, T. Rao, J. Smedley
    BNL, Upton, Long Island, New York, USA
  • E.M. Muller
    Stony Brook University, Stony Brook, USA
  
  Funding: The authors wish to acknowledge the support of the U.S. Department of Energy (DOE) under grants DE-SC0004584 (Tech-X Corp.) and DE-FG02-08ER41547 (BNL).
Beamlines at new light sources, such as the National Synchrotron Light Source II will operate at flux levels beyond the saturation level of existing diagnostics, necessitating the development of new devices. Currently, there is no detector which can span the entire flux range that is possible even in a second generation light source and will become crucial for next generation light sources. One new approach* is a diamond-based detector that will be able to monitor beam position, flux and timing to much better resolution. Furthermore, this detector also has linear response to flux over 11 orders of magnitude. However, the successful development of the detector requires thorough understanding and optimization of the physical processes involved. We will discuss the new modeling capabilities we have been implementing in the VORPAL 3D code to investigate the effects of charge generation due to absorption of x-ray photons, transport, and charge trapping. We will report results from VORPAL simulations on charge collection and how it depends on applied field, charge trapping, and the energy of absorbed photons.
*J. W. Keister, J. Smedley, D. A. Dimitrov, and R. Busby, Charge Collection and Propagation in Diamond X-ray Detectors, IEEE Transactions on Nuclear Science, 57, 2400 (2010). 		 
 
WEP165 Advanced Modeling of TE Microwave Diagnostics of Electron Clouds plasma, electron, simulation, vacuum 1803
 
  • S.A. Veitzer, D.N. Smithe, P. Stoltz
    Tech-X, Boulder, Colorado, USA
  
  Funding: Part of this work is being performed under the auspices of the U.S. Department of Energy as part of the ComPASS SciDAC project, #DE-FC02-07ER41499.
Numerical simulations of electron cloud buildup and in particular rf microwave diagnostics provide important insights into the dynamics of particle accelerators and the potential for mitigation of destabilizing effects of electron clouds on particle beams. Typical Particle-In-Cell (PIC) simulations may accurately model cloud dynamics; however, due to the large range of temporal scales needed to model side band production due to ecloud modulation, typical PIC models may not be the best choice. We present here preliminary results for advance numerical modeling of rf electron cloud diagnostics, where we replace kinetic particles with an equivalent plasma dielectric model. This model provides significant speedup and increased numerical stability, while still providing accurate models of rf phase shifts induced by electron cloud plasmas over long time scales. 		 
 
WEP196 Single-Shot Longitudinal Phase Space Measurement Diagnostics Beamline Status at the Argonne Wakefield Accelerator cavity, quadrupole, simulation, dipole 1858
 
  • M.M. Rihaoui, D. Mihalcea, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • W. Gai, J.G. Power
    ANL, Argonne, USA
  
  A single-shot longitudinal phase space diagnostics experiment is currently being commissioned at Argonne Wakefield Accelerator. The diagnostic beamline consists of two magnetic dipoles that bend the beam horizontally followed by an rf deflecting cavity that streaks the beam vertically. Using this configuration, the incoming longitudinal phase space can be mapped to a final (x,y) plane which can be directly measured, e.g., using a YAG screen. In this paper we discuss the limitations of such longitudinal phase space diagnostics and present some preliminary measurements.  
 
WEP209 Reliability Study of the AIRIX Induction Accelerator over a Functioning Period of Ten Years (2000-2010) electron, vacuum, high-voltage, controls 1882
 
  • H. Dzitko, A. Georges, B. Gouin, M. Mouillet
    CEA, Pontfaverger-Moronvilliers, France
  
  AIRIX is a high current (19 MeV, 2 kA) electron linear induction accelerator used as a 60 ns single shot X-ray source for hydrodynamic experiments. As single shot experiments are performed with the AIRIX facility, the best performances and a high reliability level must be met for each experiment. A high availability is also a key issue for the successful development of hydrotest projects. The AIRIX accelerator has been running for hydroshot experiments since 2000 and several thousands electron and X-ray beams have been produced. This paper outlines the reliability results of the AIRIX accelerator over a functioning period of ten years. Failure rates for each main subsystems are shown : injector, accelerating cells, high voltage generators, and measurement chains. We also give an overview of the most probable faults, with the associated occurrence rates, which can alter the X source of the AIRIX machine over this ten year period.  
 
WEP222 Low Energy Beam Diagnostic for APEX, the LBNL VHF Photo-injector emittance, gun, electron, cathode 1903
 
  • D. Filippetto, J.M. Byrd, M.J. Chin, C.W. Cork, S. De Santis, L.R. Doolittle, J. Feng, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, D.G. Quintas, F. Sannibale, M.E. Stuart, R.P. Wells, M.S. Zolotorev
    LBNL, Berkeley, California, USA
  
  Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
A high-repetition rate (MHz-class), high-brightness electron beam photo-gun is under construction at Lawrence Berkeley National Laboratory in the framework of the Advanced Photo-injector EXperiment (APEX). The injector gun is based on a normal conducting 187 MHz RF cavity operating in CW mode. In its first operational phase it will deliver short bunches (~ 1 to tens of picoseconds) with energy of 750keV, and bunch charges ranging from 1pC to 1nC. Different high efficiency cathode materials will be tested, and the beam quality will be studied as a function of parameters as charge, initial bunch length and transverse size, focusing strength. Both the laser and electron beam diagnostics have been designed to assure the needed flexibility. In particular a high-resolution electron diagnostic section after the photo-gun provides the necessary dynamical range for scanned beam parameters: energy and energy spread, charge and current, transverse and longitudinal phase spaces, slice properties. The photo-gun electron beam diagnostic layout is presented, and the hardware choices, resolution and achievable dynamical ranges are also discussed. 		 
 
WEP276 Development of an Advanced Barium Ion Source for a Laser-Induced-Fluorescence (LIF) Diagnostic on the Paul Trap Simulator Experiment (PTSX) ion, ion-source, vacuum, plasma 1996
 
  • H. Wang, R.C. Davidson, P. Efthimion, E.P. Gilson, R. M. Majeski
    PPPL, Princeton, New Jersey, USA
  
  The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap that simulates the nonlinear transverse dynamics of intense charged particle beam propagation through an equivalent kilometers-long magnetic alternating-gradient (AG) focusing system. Understanding the collective dynamics and instability excitations of intense charged particle beam is of great importance for a wide variety of accelerator applications. Since the optical spectrum of barium ions is better-suited to the Laser-Induced-Fluorescence (LIF) diagnostic than cesium ions, a barium ion source is being developed to replace the cesium ion source. A Laser-Induced-Fluorescence diagnostic will be able to provide in situ measurement of the radial density profile and, ultimately, the velocity distribution function of the intense charged particle beam. The new barium ion source is expected to increase the ion density as well as minimize the number of neutral barium atoms which enter the PTSX vacuum chamber. The design includes an ionizer, an extractor, and a neutral gas filter scheme. Initial test results of this new barium ion source will be presented.  
 
THOBN5 Design and Testing of Advanced Photonic Bandgap (PBG) Accelerator Structures klystron, wakefield, coupling, ion 2071
 
  • B.J. Munroe, M.A. Shapiro, R.J. Temkin
    MIT/PSFC, Cambridge, Massachusetts, USA
  • V.A. Dolgashev, S.G. Tantawi, A.D. Yeremian
    SLAC, Menlo Park, California, USA
  • R.A. Marsh
    LLNL, Livermore, California, USA
  
  Photonic Band-gap (PBG) structures continue to be an area of promising research for high gradient accelerators with wakefield suppression. Experimental results on an 11.4 GHz PBG structure tested at high power and high repetition rate at SLAC have shown that high gradients can be achieved in these structures. For PBG structures with thin rods, however, pulsed heating of the inner row of rods is a problem. Following these preliminary results, two new PBG structures have been designed. One structure, designated 1C-SW-A5.65-T4.6-Cu-PBG2-SLAC1, utilizes elliptical inner rods to reduce pulsed heating to an acceptable level; it will be tested at SLAC. A second PBG structure with round rods will be tested at 17.1 GHz at MIT. The MIT research will use the improved diagnostic access of the PBG structure to obtain a better understanding of the breakdown process. We will present preliminary results for the design and testing of these PBG structures.  
slides icon Slides THOBN5 [0.752 MB]  
 
THP183 Measurement of Femtosecond LCLS Bunches Using the SLAC A-line Spectrometer* linac, wakefield, simulation, electron 2459
 
  • Z. Huang, A. Baker, M. Boyes, J. Craft, F.-J. Decker, Y.T. Ding, P. Emma, J.C. Frisch, R.H. Iverson, J.J. Lipari, H. Loos, D.R. Walz
    SLAC, Menlo Park, California, USA
  • C. Behrens
    DESY, Hamburg, Germany
  
  We describe a novel technique and the preliminary experimental results to measure the ultrashort bunch length produced by the LCLS low-charge, highly compressed electron bunch. The technique involves adjusting the LCLS second bunch compressor followed by running the bunch on an rf zero-crossing phase of the final 550-m of linac. As a result, the time coordinate of the bunch is directly mapped onto the energy coordinate at the end of the linac. A high-resolution energy spectrometer located at an existing transport line (A-line) is then commissioned to image the energy profile of the bunch in order to retrieve its temporal information. We present measurements of the single-digit femtosecond LCLS bunch length using the A-line as a spectrometer and compare the results with the transverse cavity measurement as well as numerical simulations.  
 
THP184 Tuning of the LCLS Linac for User Operation linac, RF-structure, electron, feedback 2462
 
  • H. Loos, R. Akre, A. Brachmann, F.-J. Decker, Y.T. Ding, P. Emma, A.S. Fisher, J.C. Frisch, A. Gilevich, P. Hering, Z. Huang, R.H. Iverson, N. Lipkowitz, H.-D. Nuhn, D.F. Ratner, J.A. Rzepiela, T.J. Smith, J.L. Turner, J.J. Welch, W.E. White, J. Wu, G. Yocky
    SLAC, Menlo Park, California, USA
  
  Funding: This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515.
With the Linac Coherent Light Source (LCLS) now in its third user run, reliable electron beam delivery at various beam energies and charge levels has become of high operational importance. In order to reduce the beam tuning time required for such changes, several diagnostics and feed-forward procedures have been implemented. We report on improved lattice diagnostics to detect magnet, model, and diagnostics errors as well as on measurements of transverse RF kicks and static field contributions and corresponding correction procedures to facilitate beam energy changes. 		 
 
THP215 Performance of the Diagnostics for NSLS-II Linac Commissioning linac, booster, simulation, emittance 2525
 
  • R.P. Fliller, R. Heese, H.-C. Hseuh, M.P. Johanson, B.N. Kosciuk, D. Padrazo, I. Pinayev, J. Rose, T.V. Shaftan, O. Singh, G.M. Wang
    BNL, Upton, Long Island, New York, USA
  
  Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source currently under construction at Brookhaven National Laboratory. The NSLS-II injection system consists of a 200 MeV linac and a 3 GeV booster synchrotron and associated transfer lines. The transfer lines not only provide a means to delivering the beam from one machine to another, they also provide a suite of diagnostics and utilities to measure the properties of the beam to be delivered. In this paper we discuss the suite of diagnostics that will be used to commission the NSLS-II linac and measure the beam properties. The linac to booster transfer line can measure the linac emittance with a three screens measurement or a quadrupole scan. Energy and energy spread are measured in a dispersive section. Total charge and charge uniformity are measured with wall current monitors in the linac and transformers in the transfer line. We show that the performance of the transfer line will be sufficient to ensure the linac meets its specifications and provides a means of trouble shooting and studying the linac in future operation. 		 
 
FROBS5 1.3 GHz Superconducting RF Cavity Program at Fermilab cavity, SRF, vacuum, cryomodule 2586
 
  • C.M. Ginsburg, T.T. Arkan, S. Barbanotti, H. Carter, M.S. Champion, L.D. Cooley, C.A. Cooper, M.H. Foley, M. Ge, C.J. Grimm, E.R. Harms, A. Hocker, R.D. Kephart, T.N. Khabiboulline, J.R. Leibfritz, A. Lunin, J.P. Ozelis, Y.M. Pischalnikov, A.M. Rowe, W. Schappert, D.A. Sergatskov, A.I. Sukhanov, G. Wu
    Fermilab, Batavia, USA
  
  Funding: Work supported by Fermi Research Alliance, LLC under contract DE-AC02-07CH11359 with the U.S. Department of Energy.
At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules, for Project X, an International Linear Collider, or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described. 		 
slides icon Slides FROBS5 [3.749 MB]