Keyword: operation
Paper Title Other Keywords Page
MOA2IO02 The BNL EBPM Electronics, High Performance for Next Generation Storage Rings ion, storage-ring, feedback, experiment 1
 
  • K. Vetter
    ORNL, Oak Ridge, Tennessee, USA
  • W.X. Cheng, J. Mead, B. Podobedov, Y. Tian
    BNL, Upton, Long Island, New York, USA
  
  Funding: DOE contract DE-AC02-98CH10886
A custom state-of-the-art RF BPM (EBPM) has been developed and commissioned at the Brookhaven National Laboratory (BNL) National Synchrotron Light Source II (NSLS-II). A collaboration between Lawrence Berkeley National Laboratory (LBNL) Advanced Light Source (ALS) and BNL has proven to be a key element in the success of the NSLS-II EBPM. High stability coherent signal processing has allowed for demonstrated 200nm RMS spatial resolution and true turn-by-turn position measurement capability. Sub-micron 24 hr. stability has been demonstrated at NSLS-II by use of 0.01C RMS thermal regulation of the electronics racks without the need of active pilot tone correction. 		 
slides icon Slides MOA2IO02 [4.334 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOA2IO02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOA3CO04 Operational Experience with Fast Fiber-Optic Beam Loss Monitors for the Advanced Photon Source Storage Ring Superconducting Undulators ion, undulator, site, kicker 28
 
  • J.C. Dooling, K.C. Harkay, V. Sajaev, H. Shang
    ANL, Argonne, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under contract number DE-AC02-06CH11357.
Fast fiber-optic (FFO) beam loss monitors (BLMs) installed with the first two superconducting undulators (SCUs) in the Advanced Photon Source storage ring have proven to be a useful diagnostic for measuring deposited charge (energy) during rapid beam loss events. The first set of FFOBLMs were installed outside the cryostat of the short SCU, a 0.33-m long device, above and below the beam centerline. The second set are mounted with the first 1.1-m-long SCU within the cryostat, on the outboard and inboard sides of the vacuum chamber. The next 1.1-m-long SCU is scheduled to replace the short SCU later in 2016 and will be fitted with FFOBLMs in a manner similar to original 1.1-m device. The FFOBLMs were employed to set timing and voltage for the abort kicker (AK) system. The AK helps to prevent quenching of the SCUs during beam dumps* by directing the beam away from the SC magnet windings. The AK is triggered by the Machine Protection System (MPS). In cases when the AK fails to prevent quenching, the FFOBLMs show that losses often begin before detection by the MPS.
K. Harkay et al., these proceedings 		 
slides icon Slides MOA3CO04 [1.188 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOA3CO04  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOB3IO02 LHC Operation at 6.5 TeV: Status and Beam Physics Issues ion, luminosity, MMI, radiation 37
 
  • G. Papotti, M. Albert, R. Alemany-Fernandez, E. Bravin, G.E. Crockford, K. Fuchsberger, R. Giachino, M. Giovannozzi, G.H. Hemelsoet, W. Höfle, G. Iadarola, D. Jacquet, M. Lamont, D. Nisbet, L. Normann, T. Persson, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, M. Solfaroli Camillocci, R. Suykerbuyk, J. Wenninger
    CERN, Geneva, Switzerland
  
  LHC operation restarted in 2015 after the first Long Shutdown, planning for a 4-year long run until the end of 2018 (called Run 2). The beam energy was fixed at 6.5 TeV. The year 2015 was dedicated to establishing operation at the high energy and with 25 ns beams, in order to prepare production for the following three years. The year 2016 was the first one dedicated to production, and it turned out to be a record-breaking year, in which the goals in both peak and integrated luminosities with proton-proton beams were achieved and surpassed. This paper revisits 2015 and 2016, shortly highlighting the main facts in the timelines, recalling the parameters that characterized luminosity production, and sketching the main limitations and the main highlights of results for selected topics, including a particular focus on the beam physics issues.  
slides icon Slides MOB3IO02 [15.183 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOB3IO02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOB3CO03 RHIC Au-Au Operation at 100 GeV in Run16 ion, cavity, luminosity, electron 42
 
  • X. Gu, J.G. Alessi, E.N. Beebe, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, J.J. Butler, R. Connolly, T. D'Ottavio, K.A. Drees, W. Fischer, C.J. Gardner, D.M. Gassner, Y. Hao, M. Harvey, T. Hayes, H. Huang, R.L. Hulsart, P.F. Ingrassia, J.P. Jamilkowski, J.S. Laster, V. Litvinenko, C. Liu, Y. Luo, M. Mapes, G.J. Marr, A. Marusic, G.T. McIntyre, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, C. Naylor, S. Nemesure, I. Pinayev, V.H. Ranjbar, D. Raparia, G. Robert-Demolaize, T. Roser, P. Sampson, J. Sandberg, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, S. Tepikian, R. Than, P. Thieberger, J.E. Tuozzolo, G. Wang, Q. Wu, A. Zaltsman, K. Zeno, S.Y. Zhang, W. Zhang
    BNL, Upton, Long Island, New York, USA
  
  In order to achieve higher instantaneous and integrated luminosities, the average Au bunch intensity in RHIC has been increased by 30% compared to the preceding Au run. This increase was accomplished by merging bunches in the RHIC injector AGS. Luminosity leveling for one of the two interaction points (IP) with collisions was realized by continuous control of the vertical beam separation. Parallel to RHIC physics operation, the electron beam commissioning of a novel cooling technique with potential application in eRHIC, Coherent electron Cooling as a proof of principle (CeCPoP), was carried out. In addition, a 56 MHz superconducting RF cavity was commissioned and made operational. In this paper we will focus on the RHIC performance during the 2016 Au-Au run.  
slides icon Slides MOB3CO03 [2.173 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOB3CO03  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB10 Design of the HGVPU Undulator Vacuum Chamber for LCLS-II ion, vacuum, alignment, undulator 89
 
  • J.E. Lerch, J.A. Carter, P.K. Den Hartog, G.E. Wiemerslage
    ANL, Argonne, Illinois, USA
  
  A vacuum chamber has been designed and prototyped for the new Horizontal Gap Vertically Polarization Undulator (HGVPU) as part of the LCLS-II upgrade project. Numerous functional requirements for the HGVPU assembly constrained the vacuum chamber design. These constraints included spatial restrictions to achieve small magnet gaps, narrow temperature and alignment specifications, and minimization of wall erosion and pressure drop within the cooling channels. This led to the design of a 3.5-meter length, thin walled, extruded aluminium chamber with interior water cooling. FEA stress analysis was performed to ensure the chamber will not fail under vacuum and water pressure. A cooling scheme was optimized to ensure water flow is sufficient to maintain temperature without the risk of erosion and to minimize pres-sure drop across the chamber.  
poster icon Poster MOPOB10 [60.628 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB10  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB13 Post Irradiation Examination Results of the NT-02 Graphite Fins Numi Target ion, target, radiation, proton 99
 
  • K. Ammigan, P. Hurh, V.I. Sidorov, R.M. Zwaska
    Fermilab, Batavia, Illinois, USA
  • D. Asner, A.M. Casella, D.J. Edwards, A.L. Schemer-Kohrn, D.J. Senor
    PNNL, Richland, Washington, USA
  
  Funding: Work supported by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
The NT-02 neutrino target in the NuMI beamline at Fermilab is a 95 cm long target made up of segmented graphite fins. It is the longest running NuMI target, which operated with a 120 GeV proton beam with maximum power of 340 kW, and saw an integrated total proton on target of 6.1 x 1020. Over the last half of its life, gradual degradation of neutrino yield was observed until the target was replaced. The probable causes for the target performance degradation are attributed to radiation damage, possibly including cracking caused by reduction in thermal shock resistance, as well as potential localized oxidation in the heated region of the target. Understanding the long-term structural response of target materials exposed to proton irradiation is critical as future proton accelerator sources are becoming increasingly more powerful. As a result, an autopsy of the target was carried out to facilitate post-irradiation examination of selected graphite fins. Advanced microstructural imaging and surface elemental analysis techniques were used to characterize the condition of the fins in an effort to identify degradation mechanisms, and the relevant findings are presented in this paper. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB13  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB17 Resonant Frequency Control for the PIP-II Injector Test RFQ: Control Framework and Initial Results ion, controls, rfq, framework 109
 
  • A.L. Edelen, S. Biedron, S.V. Milton
    CSU, Fort Collins, Colorado, USA
  • D.L. Bowring, B.E. Chase, J.P. Edelen, D.J. Nicklaus, J. Steimel
    Fermilab, Batavia, Illinois, USA
  
  Funding: Work supported by Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359.
For the PIP-II Injector Test (PI-Test) at Fermilab, a four-vane radio frequency quadrupole (RFQ) is designed to accelerate a 30-keV, 1-mA to 10-mA H' beam to 2.1 MeV under both pulsed and continuous wave (CW) RF operation. The available headroom of the RF amplifiers limit the maximum allowable detuning to 3 kHz, and the detuning is controlled entirely via thermal regulation. Fine control over the detuning, minimal manual intervention, and fast trip recovery is desired. In addition, having active control over both the walls and vanes provides a wider tuning range. For this, we intend to use model predictive control (MPC). To facilitate these objectives, we developed a dedicated control framework that handles higher-level system decisions as well as executes control calculations. It is written in Python in a modular fashion for easy adjustments, readability, and portability. Here we describe the framework and present the first control results for the PI-Test RFQ under pulsed and CW operation. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB17  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB27 Superconducting Coil Winding Machine Control System ion, controls, FPGA, software 127
 
  • J.M. Nogiec, S. Kotelnikov, A. Makulski, K. Trombly-Freytag, D.G.C. Walbridge
    Fermilab, Batavia, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy under contract no. DE-AC02-07CH11359.
The Spirex magnet coil winder has been equipped with an automation system, which allows operation from both a computer and a remote control unit. This machine is about 6m long with a bridge that moves along a track and supports a rotating boom holding a spool of cable and providing cable tension. The machine control system is distributed between three layers: PC, RTOS, and FPGA providing respectively HMI, operational logic and controls. The PC stores the history of operation, shows the machine positions, status, and their history. Keeping cable tension constant is non-trivial in situations where the length of the cable changes with varying speeds. This has been addressed by a PID controller with feed forward augmentation and low-pass filters. Another challenging problem, synchronizing multiple servo motors, has been solved by designing an innovative decentralized algorithm. Extra attention was given to the safety aspects; a fail-safe, redundant safety system with interlocks has been developed, including protection for the operator and the superconducting cable against such situations as accidental over tension, or fast movement of the cable due to operational errors. 		 
poster icon Poster MOPOB27 [1.952 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB27  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB30 Development and Comparison of Mechanical Structures for FNAL 15 T Nb3Sn Dipole Demonstrator ion, dipole, collider, controls 137
 
  • A.V. Zlobin, I. Novitski
    Fermilab, Batavia, Illinois, USA
  
  Funding: *Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
Main design challenges for 15 T accelerator magnets are large Lorentz forces at this field level. The large Lorentz forces generate high stresses in the coil and mechanical structure and, thus, need stress control to maintain them at the acceptable level for brittle Nb3Sn coils and other elements of magnet mechanical structure. To provide these conditions and achieve the design field in the FNAL 15 T dipole demonstrator, several mechanical structures have been developed and analysed. The possibilities and limitations of these designs are discussed in this paper. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB30  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB33 LCLS-II Tuner Assembly for the Prototype Cryomodule at FNAL ion, cavity, cryomodule, SRF 143
 
  • Y.M. Pischalnikov, E. Borissov, T.N. Khabiboulline, J.C. Yun
    Fermilab, Batavia, Illinois, USA
  
  The tuner design for LCLS-II has been thoroughly verified and fabricated for used in the LCLS-II prototype modules. This paper will present the lessons learned during the installation of these tuners for the prototype modules at FNAL, including installation procedures, best practices, and challenges encountered.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB33  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB39 A 600 Volt Multi-Stage, High Repetition Rate GaN FET Switch ion, linac, electron, ECR 152
 
  • G.W. Saewert, D. Frolov, H. Pfeffer
    Fermilab, Batavia, Illinois, USA
  
  Using recently available GaN FETs, a 600 Volt three-stage, multi-FET switch has been developed having 2 nanosecond rise time driving a 200 Ω load with the potential of approaching 30 MHz average switching rates. Possible applications include driving particle beam choppers kicking bunch-by-bunch and beam deflectors where the rise time needs to be custom tailored. This paper reports on the engineering issues addressed, the design approach taken and some performance results of this switch.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB39  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB40 Quench Training Analysis of Nb3Sn Accelerator Magnets ion, dipole, quadrupole, magnet-design 155
 
  • S. Stoynev, K.H. Riemer, A.V. Zlobin
    Fermilab, Batavia, Illinois, USA
  
  Funding: This work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
Nb3Sn accelerator magnet technology has made significant progress during the past decades. Thanks to that 11-12 T Nb3Sn dipoles and quadrupoles are planned to be used in accelerators such as LHC in near future for the luminosity upgrade and in longer term for the LHC energy upgrade or a future Very High Energy pp Collider. However, all the state of the art Nb3Sn accelerator magnets show quite long training. This specific feature significantly raises the required design margin or limit the nominal operation field of Nb3Sn accelerator magnets and, thus, increases their cost. To resolve this problem Fermilab has launched a study aiming to analyze the relatively large amount of Nb3Sn magnet training data accumulated at Fermilab magnet test facility. The ultimate goal is to correlate magnet design and manufacturing features and magnet material properties with training performance parameters which will eventually allow us to optimize both the magnet design, fabrication and the training processes. This paper describes the general strategy of the analysis and presents the first results based on partial data processing. Conclusions and further steps are also outlined and discussed. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB40  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB44 Thyratron Replacement ion, klystron, network, linear-collider 162
 
  • I. Roth, M.P.J. Gaudreau, M.K. Kempkes, M.G. Munderville, R.E. Simpson
    Diversified Technologies, Inc., Bedford, Massachusetts, USA
  
  Funding: *Work supported by US Department of Energy under contract DE-SC0011292
Semiconductor thyristors have long been used as a replacement for thyratrons in low power or long pulse RF systems. To date, however, such thyristor assemblies have not demonstrated the reliability needed for installation in short pulse, high peak power RF stations used with many pulsed electron accelerators. The fast rising current in a thyristor tends to be carried in a small region, rather than across the whole device, and this localized current concentration can cause a short circuit failure. An alternate solid-state device, the insulated-gate bipolar transistor (IGBT), can readily operate at the speed needed for the accelerator, but commercial IGBTs cannot handle the voltage and current required. It is, however, possible to assemble these devices in arrays to reach the required performance levels without sacrificing their inherent speed. Diversified Technologies, Inc. (DTI) has patented and refined the technology required to build these arrays of series-parallel connected switches. DTI is currently developing an affordable, reliable, form-fit-function replacement for the klystron modulator thyratrons at SLAC capable of pulsing at 360 kV, 420 A, 6μs, and 120 Hz. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB44  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB46 Long Pulse Solid-State Pulsed Power Systems Built to ESS Specifications ion, klystron, high-voltage, power-supply 165
 
  • I. Roth, M.P.J. Gaudreau, M.K. Kempkes, M.G. Munderville, R.E. Simpson
    Diversified Technologies, Inc., Bedford, Massachusetts, USA
  • J. Domenge
    Sigma Phi Electronics, Wissembourg, France
  • J.L. Lancelot
    Sigmaphi, Vannes, France
  
  Diversified Technologies, Inc. (DTI), in partnership with SigmaPhi Electronics (SPE) has built three long pulse solid-state klystron transmitters to meet spallation source requirements. Two of the three units are installed at CEA Saclay and the National Institute of Nuclear and Particle Physics (IN2P3), where they will be used as test stands for the European Spallation Source (ESS). The systems delivered to CEA and IN2P3 demonstrate that the ESS klystron modulator specifications (115 kV, 25 A per klystron, 3.5 ms, 14 Hz) have been achieved in a reliable, manufacturable, and cost-effective design. There are only minor modifications required to support transition of this design to the full ESS Accelerator, with up to 100 klystrons. The systems will accommodate the recently-determined increase in average power (~660 kW), can offer flicker-free operation, are equally-capable of driving Klystrons or MBIOTs, and are designed for an expected MTBCF of over ten years, based on operational experience with similar systems.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB46  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB49 Persistent Current Effects in RHIC Arc Dipole Magnets Operated at Low Currents ion, dipole, ion-effects, detector 170
 
  • X. Wang, S. Caspi, S.A. Gourlay, G.L. Sabbi
    LBNL, Berkeley, California, USA
  • A.K. Ghosh, R.C. Gupta, A.K. Jain, P. Wanderer
    BNL, Upton, Long Island, New York, USA
  
  Funding: BNL work was supported by Brookhaven Science Associates, LLC under Contract# DESC0012704 with the U.S. DOE. LBNL work was supported by the U.S. DOE under Contract# DEAC02- 05CH11231.
The Relativistic Heavy Ion Collider (RHIC) arc dipoles at Brookhaven National Laboratory are operated at low field for low energy Au-Au studies. Indications of strong nonlinear magnetic fields have been observed at these low currents due to the persistent current effects of superconducting NbTi filaments. We report the details of the measurement and calculation of the field errors due to persistent current effect. The persistent current induced field errors calculated with a model based on the strand magnetization data agree well with the measurements of a spare arc dipole magnet. The dependence of the persistent current effects on the park current is calculated based on the validated model. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB49  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB51 High-Efficiency 500-W RF-Power Modules for UHF ion, klystron, ISOL, proton 174
 
  • F.H. Raab
    Green Mountain Radio Research, Boone, USA
  
  Funding: U.S. DoE DE-SC0002548, DE-SC0006200, and DE-SC0006237. GMRR IR&D.
GMRR has developed solid-state RF-power modules that deliver up to 650 W at frequencies from 325 to 704 MHz. The nominal output of 500 W is delivered with an overall efficiency from 79% at 704 MHz to 83% percent at 325 MHz. In contrast to conventional solid-state power amplifiers, high efficiency is maintained over a wide range of output powers; e.g., 70 percent or better for outputs of 30 W or higher. Each 500-W module contains five 120-W RF power amplifiers (PAs) and a Gysel* splitter and combiner. The class-F** PAs employ GaN FETs and produce over 120 W with efficiencies from 82-86%. A class-S modulator maintains high efficiency over nearly the entire range of amplitudes. Supporting hardware includes a control computer, DSP, low-level RF amplifiers, and drivers. The 500-W modules are intended to be building blocks of a multi-kW RF power source. A system based these modules will consume 1/3 to 1/2 of the prime power required by a system based upon klystrons or conventional solid-state amplifiers and will have significantly lower cooling requirements.
* U. H. Gysel, Int. Microwave Symp. Digest, May 12 - 14, 1975.
** F. H. Raab et al., IEEE Trans. Microwave Theory Tech., March 2002.
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB51  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOB72 Update on CW 8 kW 1.5 GHz Klystron Replacement ion, klystron, ISOL, controls 232
 
  • A.V. Smirnov, S. Boucher
    RadiaBeam Systems, Santa Monica, California, USA
  • R.B. Agustsson, D.I. Gavryushkin, J.J. Hartzell, K.J. Hoyt, A.Y. Murokh, T.J. Villabona
    RadiaBeam, Santa Monica, California, USA
  • G.R. Branner, K.S. Yuk
    UC Davis, Davis, USA
  • V. Khodos
    Sierra Nevada Corporation, Irvine, USA
  
  Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC0013136).
JLAB upgrade program requires a ~8 kW, 1497 MHz amplifier operating at more than 55-60% efficiency, and 8 kW CW power to replace up to 340 klystrons. One of possibilities for the klystron replacement is usage of high electron mobility packaged GaN transistors applied in array of highly efficient amplifiers using precise in-phase, low-loss combiners-dividers. Design features and challenges related to amplifier modules and radial multi-way dividers/combiners are discussed including HFSS simulations and measurements. 		 
poster icon Poster MOPOB72 [1.199 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB72  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUA1IO03 Technological Challenges in the Path to 3.0 MW at the SNS Accelerator ion, target, neutron, rfq 246
 
  • K.W. Jones
    ORNL, Oak Ridge, Tennessee, USA
  
  This talk discusses the design and anticipated challenges associated with upgrading the SNS beam power from the original 1.4 MW baseline design to the upgrade goal of 3 MW.  
slides icon Slides TUA1IO03 [22.843 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA1IO03  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUA2CO03 A Novel Technique of Power Control in Magnetron Transmitters for Intense Accelerators ion, controls, cavity, power-supply 271
 
  • G.M. Kazakevich, R.P. Johnson, M.L. Neubauer
    Muons, Inc, Illinois, USA
  • V.A. Lebedev, W. Schappert, V.P. Yakovlev
    Fermilab, Batavia, Illinois, USA
  
  A novel concept of a high-power magnetron transmitter allowing dynamic phase and power control at the frequency of locking signal is proposed. The transmitter compensating parasitic phase and amplitude modulations inherent in Superconducting RF (SRF) cavities within closed feedback loops is intended for powering of the intensity-frontier superconducting accelerators. The concept uses magnetrons driven by a sufficient resonant (injection-locking) signal and fed by the voltage which can be below the threshold of self-excitation. This provides an extended range of power control in a single magnetron at highest efficiency minimizing the cost of RF power unit and the operation cost. Proof-of-principle of the proposed concept demonstrated in pulsed and CW regimes with 2.45 GHz, 1kW magnetrons is discussed here. A conceptual scheme of the high-power transmitter allowing the dynamic wideband phase and mid-frequency power controls is presented and discussed.  
slides icon Slides TUA2CO03 [0.714 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA2CO03  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA07 IoT Application in the Control System of the BEPCII Power Supplies ion, controls, power-supply, status 302
 
  • C.H. Wang, L.F. Li, X.L. Wang
    IHEP, Beijing, People's Republic of China
  • C.P. Chu
    MSU, East Lansing, Michigan, USA
  
  Funding: This prject is support by NSFC(1137522)
In recent years in the development of Internet technology, the Internet of things (IoT) has begun to apply to each domain. The paper introduces the idea how to apply IoT to the accelerator control system and take the existing control system of the BEPCII power supplies as an example for IoT application. It not only introduce the status of the control system of the BEPCII power supplies, but also present a solution how to apply IoT to the existing control system. The purpose is to make the control system more intelligent and automatically identify what and where problem when the alarm of the control system of the power supplies. That means that IoT can help to automatically identify which crate and which PSC board inserted in the crates and which PSI sittiing in the power supply crates as well as the optic fiber cables between the PSCs and the PSIs. It is great convenient for the maintainer to use a mobile phone to diagnose faults and create the electronic maintenance record. 		 
poster icon Poster TUPOA07 [0.762 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA07  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOA71 Beam Stability During Top Off Operation at NSLS-II Storage Ring ion, feedback, injection, storage-ring 425
 
  • W.X. Cheng, B. Bacha, Y. Li, O. Singh, Y. Tian
    BNL, Upton, Long Island, New York, USA
  
  NSLS-II storage ring started top off operation since Oct 2015. User operation current has been gradually increased to 250mA. Observations of beam stabilities during top-off operations will be presented. Total beam current was typically maintained within ±0.5% and bunch to bunch current variation was less than 20%. Injection transition during top-off was measured bunch by bunch digitizer, and BPM to analyze the orbit motion at various bandwidths (turn by turn, 10kHz and 10Hz rate). Coupled bunch unstable motions were monitored. As the vacuum pressure improves, fast-ion instability is not as severe compared to early stage of commissioning/operation, but still observed as the dominant instability. Resistive wall instability is noticed as more in-vacuum-undulator (IVU) gaps closed. xBPM measured photon stability and electron beam stability at top off injection have been evaluated. Short term and long term orbit stabilities will be reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA71  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOB09 Solid-State Pulsed Power System for a Stripline Kicker ion, kicker, ISOL, simulation 500
 
  • N. Butler, M.P.J. Gaudreau, M.K. Kempkes, M.G. Munderville, F.M. Niell, R.E. Simpson
    Diversified Technologies, Inc., Bedford, Massachusetts, USA
  
  Funding: *Work supported by US Department of Energy contract DE-SC0004255
Diversified Technologies, Inc. (DTI) has designed, built, and demonstrated a prototype pulse amplifier for stripline kicker service capable of less than 5 ns rise and fall times, 5 to 90 ns pulse lengths, peak power greater than 13.7 MW at pulse repetition rates exceeding 100 kHz, and measured jitter under 100 ps. The resulting pulse is precise and repeatable, and will be of great interest to accelerator facilities requiring electromagnetic kickers. The pulse generator is based on the original specifications for the NGLS fast deflector. DTI's planar inductive adder configuration uses compensated-silicon power transistors in low inductance leadless packages with a novel charge-pump gate drive to achieve unmatched performance. The unit was brought to LBNL, compared with other researcher's efforts, and was judged very favorably. A number of development prototypes have been constructed and tested, including a successful 18.7 kV, 749 A unit. The modularity of this design will enable configuration of systems to a wide range of potential applications in both kickers and other high speed requirements, including high performance radars, directed energy systems, and excimer lasers. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB09  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOB14 An Accurate and Efficient Numerical Integrator for Pair-Wise Interaction ion, proton, software, simulation 514
 
  • A.A. Al Marzouk, B. Erdelyi
    Northern Illinois University, DeKalb, Illinois, USA
  
  We are developing a new numerical integrator based on Picard iteration method for Coulomb collisions. The aim is to achieve a given prescribed accuracy most efficiently. The integrator is designed to have adaptive time stepping, variable order, and dense output. It also has an automatic selection of the order and the time step. We show that with a good estimation of the radius of convergence of the expansion, we can obtain the optimal time step size. We also show how the optimal order of the integration is chosen to maintain the required accuracy. For efficiency, particles are distributed over time bins and propagated accordingly.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB14  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOB23 Electron Cloud Simulations for the Low-Emittance Upgrade at the Cornell Electron Storage Ring ion, electron, positron, synchrotron 542
 
  • J.A. Crittenden, Y. Li, S. Poprocki, J.E. San Soucie
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: Work supported by the National Science Foundation DMR 13-32208
The Cornell Electron Storage Ring operations group is planning a major upgrade of the storage ring performance as an X-ray user facility. The principal modification foresees replacing the former e−e+ interaction region with six double-bend achromats, reducing the emittance by a factor of four. The beam energy will increase from 5.3 to 6.0 GeV and single-beam operation will replace the present two-beam e−e+ operation. The initial phase of the project will operate a single positron beam, so electron cloud buildup may contribute to performance limitations. This work describes a synchrotron radiation analysis of the new ring, and employs its results to provide ring-wide estimates of cloud buildup and consequences for the lattice optics. 		 
poster icon Poster TUPOB23 [4.832 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB23  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOA14 Resistive Wall Growth Rate Measurements in the Fermilab Recycler ion, impedance, cavity, injection 719
 
  • R. Ainsworth, P. Adamson, A.V. Burov, I. Kourbanis
    Fermilab, Batavia, Illinois, USA
  
  Impedance could represent a limitation of running high intensity beams in the Fermilab recycler. With high intensity upgrades foreseen, it is important to quantify the impedance. To do this, studies have been performed measuring the growth rate of presumably the resistive wall instability. The growth rates at varying intensities and chromaticities are shown. The measured growth rates are compared to ones calculated with the resistive wall impedance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA14  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOA16 Fermilab Recycler Collimation System Design ion, collimation, proton, radiation 726
 
  • B.C. Brown, P. Adamson, R. Ainsworth, D. Capista, K.J. Hazelwood, I. Kourbanis, N.V. Mokhov, D.K. Morris, M.J. Murphy, V.I. Sidorov, E.G. Stern, I.S. Tropin, M.-J. Yang
    Fermilab, Batavia, Illinois, USA
  
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.
To provide 700 kW proton beams for neutrino production in the NuMI facility, we employ slip stacking in the Recycler with transfer to the Main Injector for recapture and acceleration. Slip stacking with 12 Booster batches per 1.33 sec cycle of the Main Injector has been implemented and extensive operation with 8 batches and 10 batches per MI cycle has been demonstrated. Operation in this mode since 2013 shows that loss localization is an essential component for long term operation. Beam loss in the Recycler will be localized in a collimation region with design capability for absorbing up to 2 kW of lost protons in a pair of 20-Ton collimators (absorbers). This system will employ a two stage collimation with a thin Mo scattering foil to define the bottom edge of both the injected and decelerated-for-slipping beams. Optimization and engineering design of the collimator components and radiation shielding are based on comprehensive MARS15 simulations predicting high collimation efficiency as well as tolerable levels of prompt and residual radiation. The system installation during the Fermilab 2016 facility shutdown will permit commissioning in the subsequent operating period. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA16  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOA24 Installation and Commissioning of an Ultrafast Electron Diffraction Facility as Part of the ATF-II Upgrade ion, experiment, MMI, electron 742
 
  • M.A. Palmer, M. Babzien, M.G. Fedurin, C. Folz, M. Fulkerson, K. Kusche, J.J. Li, R. Malone, T.V. Shaftan, J. Skaritka, L. Snydstrup, C. Swinson, F.J. Willeke
    BNL, Upton, Long Island, New York, USA
  
  Funding: This work was funded by the US Department of Energy under contract DE-SC0012704.
The Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL) is presently carrying out an upgrade, ATF-II, which will provide significantly expanded experimental space and capabilities for its users. One of the new capabilities being integrated into the ATF-II program is an Ultrafast Electron Diffraction (UED) beam line, which was originally deployed in the BNL Source Development Laboratory. Inclusion of the UED in the ATF-II research portfolio will enable ongoing development and extension of the UED capabilities for use in materials research. We discuss the design, installation and commissioning of the UED beam line at ATF-II as well as plans for future upgrades. 		 
poster icon Poster WEPOA24 [18.332 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA24  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOA52 Modeling and Simulation of RFQs for Analysis of Fields and Frequency Deviations with Respect to Internal Dimensional Errors ion, rfq, simulation, resonance 810
 
  • Y.W. Kang, S.W. Lee
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: This work was supported by SNS through UT­Battelle, LLC, under contract DE­AC05­00OR22725 for the U.S.DOE.
Performance of radio frequency quadrupole (RFQ) is sensitive to the errors in internal dimensions which shift resonance frequency and distort field distribution on the beam axis along the structure. The SNS RFQ has been retuned three times to compensate the deviations in frequency and field flatness with suspected dimensional changes since the start of the project for continuous operation with H− ion beams. SNS now has a new RFQ as a spare that is installed in beam test facility (BTF), a low energy test accelerator. In order to understand and predict the performance deviation, full 3D modeling and simulation were performed for the SNS RFQs. Field and frequency errors from hypothetical transverse vane perturbations, and vane erosion (and metal deposition such as Cesium introduced by the ion source operation) at the low energy ends are discussed. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA52  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOA60 Design Considerations for the Fermilab PIP-II 800 MeV Superconducting Linac ion, linac, cavity, focusing 826
 
  • A. Saini
    Fermilab, Batavia, Illinois, USA
  
  Proton Improvement Plan (PIP)-II is a proposed upgrade of existing proton accelerator complex at Fermilab. It is primarily based on construction of a superconducting (SC) linear accelerator (linac) that would be capable to operate in the continuous wave and pulsed modes. It will accelerate 2 mA H− ion beam up to 800 MeV. Among the various technical and beam optics issues associated with high beam power ion linacs, beam mismatch, uncontrolled beam losses, halo formation and potential element's failures are the most critical elements that largely affect performance and reliability of the linac. This paper reviews these issues in the framework of PIP-II SC linac and discusses experience accumulated in the course of this work.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA60  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB02 Simulation of Swap-Out Reliability for the Advance Photon Source Upgrade ion, injection, simulation, lattice 881
 
  • M. Borland
    ANL, Argonne, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The proposed upgrade of the Advanced Photon Source (APS) to a multibend achromat lattice relies on the use of swap-out injection to accommodate the small dynamic acceptance, allow use of unusual insertion devices, and minimize collective effects at high single-bunch charge. This, combined with the short beam lifetime, will make injector reliability even more important than it is for top-up operation. We used historical data for the APS injector complex to obtain probability distributions for injector up-time and down-time durations. Using these distributions, we simulated several years of swap-out operation for the upgraded lattice for several operating modes. The results indicate that obtaining very high availability of beam in the storage ring will require improvements to injector reliability. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB04 Beamline-Controlled Steering of Source-Point Angle at the Advanced Photon Source ion, EPICS, controls, feedback 887
 
  • L. Emery, G.I. Fystro, H. Shang, M.L. Smith
    ANL, Argonne, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357
An EPICS-based steering software system has been implemented for beamline personnel to directly steer the angle of the synchrotron radiation sources at the Advanced Photon Source. A script running on a workstation monitors "start steering" beamline EPICS records, and effects a steering by the value of "angle request" EPICS records that beamlines have set. The new system effectively bypasses floor coordinators and MCR operators, and makes the steering process much faster than before, although these older protocols can still be used. As with the original steering there are EPICS alarm limits that prevent large steering from occurring and avoid other problems. Error messages and statuses, OPI windows and alarm configurations are provided to the beamlines and the accelerator operators. Underpinning this new steering protocol is the recent refinement of the global orbit feedback process whereby feedforward of dipole corrector set points and orbit set points are used to create a local steering bump in a rapid and seamless way. In principle and in practice, many simultaneous steering commands from many beamlines are possible. We report on a complete 3-month run of experience. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB04  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB05 Operational Experience With Beam Abort System for Superconducting Undulator Quench Mitigation ion, kicker, simulation, beam-losses 890
 
  • K.C. Harkay, J.C. Dooling, V. Sajaev, J. Wang
    ANL, Argonne, Illinois, USA
  
  Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
A beam abort system has been implemented in the Advanced Photon Source storage ring. The abort system works in tandem with the existing machine protection system (MPS), and its purpose is to control the beam loss location and, thereby, minimize beam loss-induced quenches at the two superconducting undulators (SCUs). The abort system consists of a dedicated horizontal kicker designed to kick out all the bunches in a few turns after being triggered by MPS. The abort system concept was developed on the basis of single- and multi-particle tracking simulations using elegant and bench measurements of the kicker pulse. Performance of the abort system–kick amplitudes and loss distributions of all bunches–was analyzed using beam position monitor (BPM) turn histories, and agrees reasonably well with the model. Beam loss locations indicated by the BPMs are consistent with the fast fiber-optic beam loss diagnostics described elsewhere [1]. Operational experience with the abort system, various issues that were encountered, limitations of the system, and quench statistics are described.
[1] J. Dooling et al., these proceedings.
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB05  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB07 Dielectrically-Loaded Waveguide as a Short Period Superconducting Microwave Undulator ion, undulator, GUI, brightness 897
 
  • R. Kustom, A. Nassiri, K.J. Suthar, G.J. Waldschmidt
    ANL, Argonne, Illinois, USA
  
  The HEM12 mode in a cylindrical, dielectrically-loaded waveguide provides E and H fields on the central axis that are significantly higher than the fields on the conducting walls. The waveguide is designed to operate near its cutoff frequency where the wavelength and phase velocity vary significantly to enable tuning of the equivalent undulator wavelength. The operating frequency would range from 18 - 24 GHz. It would be possible to generate coherent, high-energy 45 - 65 KeV x-rays from the fundamental mode which are tunable over a 20% energy range by changing the source frequency while maintaining constant field strengths. The x-ray brilliance of the microwave undulator would be 3 times higher at 56-KeV and 7 times higher at 66 KeV than what is available with the APS 1.8 cm period Superconducting Wire Undulator. Since the loss factor of sapphire is very low at cryogenic temperatures, it is possible to consider a superconducting microwave undulator, although resistive losses of ~200 to 700 W/m may be a bit too high for CW operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB07  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB13 Online Minimization of Vertical Beam Sizes at APS ion, storage-ring, lattice, photon 916
 
  • Y.P. Sun
    ANL, Argonne, Illinois, USA
  
  In this paper, online minimization of vertical beam sizes along the APS (Advanced Photon Source) storage ring is presented. A genetic algorithm (GA) was developed and employed for the online optimization in the APS storage ring. A total of 59 families of skew quadrupole magnets were employed as knobs to adjust the coupling and the vertical dispersion in the APS storage ring. Starting from initially zero current skew quadrupoles, small vertical beam sizes along the APS storage ring were achieved in a short optimization time of one hour. The optimization results from this method are briefly compared with the one from LOCO (Linear Optics from Closed Orbits) response matrix correction.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB13  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB19 Summary of Cs2te Photocathode Performance and Improvements in the High-Gradient, High-Charge AWA Drive Gun cathode, ion, gun, wakefield 934
 
  • E.E. Wisniewski, S.P. Antipov, M.E. Conde, D.S. Doran, W. Gai, C.-J. Jing, W. Liu, J.G. Power, J.Q. Qiu, C. Whiteford
    ANL, Argonne, Illinois, USA
  • S.P. Antipov, C.-J. Jing, J.Q. Qiu
    Euclid TechLabs, LLC, Solon, Ohio, USA
  
  Funding: Argonne, a U.S.A. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.
The AWA L-band, high-charge photoinjector for the 70 MeV drive beamline has been operating for almost 3 years at the Argonne Wakefield Accelerator (AWA) facility. at Argonne National Laboratory (ANL). The gun operates at high-field (85 MV/m peak field on the cathode) and has a high quantum efficiency (QE) Cesium telluride photocathode with a large area (30 mm diameter). It produces high-charge, short pulse, single bunches (Q > 100 nC) as well as long bunch-trains (Q > 600 nC) for wakefield experiments (high peak current). During the first two years of operation, photocathode performance was evaluated and areas of improvement were identified. After study, consideration and consultation, steps were taken to improve the performance of the photocathode. So far, in total, three photocathodes have been fabricated on-site, installed and operated in the gun. Improvements made to the photocathode plug, vacuum system, and gun operation are detailed. The results include vastly improved conditioning times, better cathode performance, and QE above 4% for over 11 months. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB19  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB23 Performance of the Full-Length Vertical Polarizing Undulator Prototype for LCLS-II ion, undulator, FEL, electron 946
 
  • N.O. Strelnikov, E. Gluskin, I. Vasserman, J.Z. Xu
    ANL, Argonne, Illinois, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357
As part of the LCLS-II R&D program, a novel 3.4-meter long undulator prototype with horizontal main magnetic field and dynamic force compensation - called the horizontal gap vertical polarization undulator (HGVPU) - has recently been developed at the Advanced Photon Source (APS). Initial steps of the project included designing, building, and a testing 0.8-meter long prototype. Extensive mechanical testing of the HGVPU has been carried out. The magnetic tuning was accomplished by applying a set of magnetic shims. As a result, the performance of the HGVPU meets all the stringent requirements for the LCLS-II insertion device, which includes limits on the field integrals and phase errors for all operational gaps, as well as the reproducibility and accuracy of the gap settings. The HGVPU has been included in the baseline of the LCLS-II project for the hard x-ray undulator line. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB23  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB66 NSLS-II Post Mortem Function Development and Data Analysis of Beam Dump ion, cavity, status, synchrotron 1039
 
  • G.M. Wang, W.X. Cheng, J. Choi, L. Doom, K. Ha, T.V. Shaftan, R.M. Smith, J. Tagger, Y. Tian
    BNL, Upton, Long Island, New York, USA
  • R.V. Madelon
    University of Orleans, Orleans, France
  
  The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. The storage ring was commissioned in 2014 and transitioned to routine operations in the December of the same year. At this point the facility hosts 14 operating beam lines with beam current upto 250 mA. During beamline operation, various sources (protection system or subsystem malfunction) may cause beam dump. To identify the beam trip sources and improve the operation reliability, post mortem function was developed in NSLS-II to capture the sub-systems status and beam information prior and after beam dump, including RF system, power supply, BPMs and active interlock system. Most of the trip events have been identified and related source was improved. In this paper, we'll present the post mortem function and data application.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB66  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOB70 Mechanical Straightening of the 3-m Accelerating Structures at the Advanced Photon Source ion, linac, photon, alignment 1051
 
  • D.J. Bromberek, W.G. Jansma, T.L. Smith, G.J. Waldschmidt
    ANL, Argonne, Illinois, USA
  
  A project is underway at the Advanced Photon Source to mechanically straighten the thirteen 3 meter accelerating structures in the Linac in order to minimize transverse wakefield, and improve charge transport efficiency and beam quality. Flexure supports allow positioning of the structures in the X & Y directions. Mechanical design of the flexure support system, straightening techniques, mechanical measurement methods, and mechanical & RF results will be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB70  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THA1CO05 Thermal Modeling and Cryogenic Design of a Helical Superconducting Undulator Cryostat ion, cryogenics, undulator, radiation 1064
 
  • Y. Shiroyanagi, J.D. Fuerst, Q.B. Hasse, Y. Ivanyushenkov
    ANL, Argonne, Illinois, USA
  
  A conceptual design for a helical superconducting undulator (HSCU) for the Advanced Photon Source (APS) at Argonne National Laboratory (ANL) has been completed. The device differs sufficiently from the existing APS planar superconducting undulator (SCU) design to warrant development of a new cryostat based on value engineering and lessons learned from the existing planar SCU. Changes include optimization of the existing cryocooler-based refrigeration system and thermal shield as well as cost reduction through the use of standard vacuum hardware. The end result is a design that provides significantly larger 4.2 K refrigeration margin in a smaller package for greater installation flexibility in the APS storage ring. This paper presents ANSYS-based thermal analysis of the cryostat, including estimated static and dynamic (beam-induced) heating, and compares the new design with the existing planar SCU cryostat.
Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. 		 
slides icon Slides THA1CO05 [3.905 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THA1CO05  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THA1CO06 Status of the Development of Superconducting Undulators for Storage Rings and Free Electron Lasers at the Advanced Photon Source undulator, ion, photon, vacuum 1068
 
  • Y. Ivanyushenkov, C.L. Doose, J.F. Fuerst, E. Gluskin, K.C. Harkay, Q.B. Hasse, M. Kasa, Y. Shiroyanagi, D. Skiadopoulos, E. Trakhtenberg
    ANL, Argonne, Illinois, USA
  • P. Emma
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Development of superconducting undulator (SCU) technology continues at the Advanced Photon Source (APS). Experience of building and successful operation of the first short-length, 16-mm period length superconducting undulator SCU0 paved a way for the second 1-m long, 18-mm period device, SCU1, which is in operation since May 2015. The APS SCU team has also built and tested a 1.5-m long, 21-mm period undulator as a part of LCLS SCU R&D program aiming at demonstration of SCU technology availability for free electron lasers. This undulator successfully achieved all the requirements including a phase error of 5 degree rms. Our team is currently completing one more 1-m, 18-mm period undulator that will replace the SCU0. We are also working on a helical SCU for the APS. The status of these projects will be presented. 		 
slides icon Slides THA1CO06 [3.545 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THA1CO06  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOA45 Update of the SEY Measurement at Fermilab Main Injector ion, electron, vacuum, proton 1190
 
  • Y. Ji
    IIT, Chicago, Illinois, USA
  • L.K. Spentzouris
    Illinois Institute of Technology, Chicago, Illinois, USA
  • R.M. Zwaska
    Fermilab, Batavia, Illinois, USA
  
  Studies of in-situ Secondary electron yield (SEY) mea- surements of material samples at the Main Injector (MI) beam pipe wall location started in 2013. [2, 3] These studies aimed at understanding how the beam conditioning of differ- ent materials evolve if they function as MI vacuum chamber walls. The engineering run of the SEY measurement test stand was finished in 2014. From 2014 to 2016 the Fermilab accelerator intensity has increased from 24 × 1012 protons to 42 × 1012 protons. The beam conditioning effect on SS316L and TiN coated SS316L has been observed throughout this period. [1] Improvement of the data acquisition procedure and hardware has been performed. A deconditioning pro- cess was observed during the accelerator annual shut down in 2016.  
poster icon Poster THPOA45 [3.113 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA45  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOA60 Status of PLSII Operation ion, insertion, insertion-device, impedance 1223
 
  • T.-Y. Lee
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  As the upgrade of PLS, PLSII is a 3 GeV light source in 12 super-periods (281.8 m circumference) with 5.8 nm design emittance and can store electron beam up to 400 mA with 3 superconducting RF cavities. Its most unique characteristic is that it has a short straight section and a long straight section for each cell (24 straight sections) and up to 20 insertion devices can be installed. But, as the installed insertion devices, particularly in-vacuum insertion devices, are sources of high impedance, these are quite challenging for high current operation. Current status of PLSII operation and future plans are described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA60  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOA64 MAX IV Storage Ring Magnet Installation Procedure ion, storage-ring, vacuum, MMI 1234
 
  • K. Åhnberg, M.A.G. Johansson, P.F. Tavares, L. Thånell
    MAX IV Laboratory, Lund University, Lund, Sweden
  
  The MAX IV facility consists of a 3 GeV storage ring, a 1.5 GeV storage ring and a full energy injector linac. The storage ring magnets are based on an integrated "magnet block" concept. Each magnet block holds several consecutive magnet elements. The 3 GeV ring consists of 140 magnet blocks and 1.5 GeV ring has 12 magnet blocks. During the installation, procedures were developed to guarantee block straightness. This article discusses the installation procedure from a mechanical point of view and presents measurement data of block straightness and ring performance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA64  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
FRA2IO01 Development and Application of Online Optimization Algorithms ion, injection, GUI, coupling 1287
 
  • X. Huang
    SLAC, Menlo Park, California, USA
  
  Funding: DOE
Automated tuning is an online optimization process. It can be faster and more efficient than manual tuning and can lead to better performance. Automated tuning is an online optimization process. It is more efficient than manual tuning and can lead to better performance. It may also substitute or improve upon model based methods. Noise tolerance is a fundamental challenge to online optimization algorithms. We discuss our experience in developing a high efficiency, noise-tolerant optimization algorithm, the RCDS method, and the successful application of the algorithm to various real-life accelerator problems. Experience with a few other online optimization algorithms are also discussed. A performance stabilizer and an interactive optimization GUI are presented. 		 
slides icon Slides FRA2IO01 [3.601 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-FRA2IO01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)