Keyword: kicker
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MOPMB052 On-axis Injection using a Sin Wave RF Kicker injection, storage-ring, lattice, emittance 211
 
  • B.C. Jiang, Y.B. Leng, S.Q. Tian, L.Y. Yu, M.Z. Zhang, Q.L. Zhang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  
  On-axis injection is one of the critical issues for an ul-tra-low emittance storage ring which holds a rather small dynamic aperture. In order to reduce the challenges of the fast pulsed kicker design, a sin wave RF kicker is studied which is suitable for longitudinal on-axis injection. Since the injected bunch is longitudinally apart from the stored bunches, the location of the stored bunches can be at the π knot of the sin wave, while the injected bunches are launched at a phase around π/2+n·π. At this situation the injected bunches will receive a transverse kick, however the store bunches are almost un-affected.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB052  
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MOPMR002 Bunch by Bunch Position Measurement and Analysis at PLS-II injection, operation, betatron, pick-up 232
 
  • J. Lee, M.-H. Chun, I. Hwang, D.T. Kim, G. Kim, T.-Y. Lee, D.C. Shin, S. Shin
    PAL, Pohang, Republic of Korea
  
  Beam dynamic phenomena described by bunch-by-bunch motion are important issues for a storage ring and are described by various theoretical formalisms. Direct measurements of the beam position related to different dynamical mechanisms are a useful information to accelerator optimization. In PLS-II, 20 GHz sampling oscilloscope synchronized with injection event (or triggered by beam loss signal) is used to measure direct bunch by bunch motion. Based on the measured data, the principal component analysis had been performed to get the insight into beam dynamic phenomena such as couple bunch instability and beam oscillation due to kicker leakage. In this paper, we will describe the measurement method and the result of analysis for coupled bunch instability.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR002  
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MOPMR031 Investigation of Injection Losses at the Large Hadron Collider with Diamond Based Particle Detectors injection, proton, flattop, detector 310
 
  • O. Stein, W. Bartmann, F. Burkart, B. Dehning, V. Kain, R. Schmidt, D. Wollmann
    CERN, Geneva, Switzerland
  • E. Griesmayer
    CIVIDEC Instrumentation, Wien, Austria
  
  During the operation of the Large Hadron Collider (LHC) in 2015, increased injection losses were observed. To minimize stress on accelerator components in the injection regions of the LHC and to guarantee an efficient operation these losses needed to be understood and possible mitigation techniques should be studied. Measurements with diamond particle detectors revealed the loss structure with ns-resolution for the first time. Based on these measurements, recaptured beam from the Super Proton Synchrotron (SPS) surrounding the nominal bunch train was identified as the major contributor to the injection loss signals. Methods to reduce the recaptured beam in the SPS were successfully tested and verified with the diamond particle detectors. In this paper the detection and classification of LHC injection losses are described. The methods to reduce these losses and verification measurements are presented and discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR031  
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MOPMY001 Beam Dynamics Analysis for the Ultra-fast Kicker in Circular Cooler Ring of JLEIC electron, emittance, cavity, recirculation 510
 
  • Y.L. Huang
    IMP/CAS, Lanzhou, People's Republic of China
  • R.A. Rimmer, H. Wang, S. Wang
    JLab, Newport News, Virginia, USA
  
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
An ultra-fast kicker system consist of four quarter wavelength resonator based deflecting cavities was developed that simultaneously resonates at 10 subharmonic modes of the 476.3MHz bunch repetition frequency, thus every 10th bunch in the bunch train will experience a transverse kick while all the other bunches are undisturbed. This fast kicker is developed for the Energy Recovery Linac (ERL) based electron Circular Cooler Ring (CCR) in the proposed Jefferson Lab Electron Ion Collider (JLEIC, previously MEIC). The electron bunches can be reused 10-30 turns thus the beam current in the ERL can be reduced to 1/10 - 1/30 (150mA - 50mA) of the cooling bunch current (1.5A). In this paper, several methods to synthesis such a kicker waveform will be discussed with the comparison of beam dynamics tracking in Elegant. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY001  
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MOPOR003 Simulation Studies and Measurements of Beam Instabilities Caused by the Kicker Impedance at High Intensities in the 3-GeV RCS of J-PARC simulation, impedance, injection, betatron 589
 
  • P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, M. Kinsho, M. Nomura, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, M. Yamamoto
    JAEA/J-PARC, Tokai-mura, Japan
  
  The transverse impedance of the extraction kickers is a significant beam instability source in the 3-GeV Rapid Cycling Synchrotron of J-PARC. ORBIT code was developed for space charge and beam instability simulations by successfully introducing realistic time dependent machine parameters. The beam instability at high intensities, especially at the designed 1 MW beam power was found be very critical. As there was no practical measure yet to reduce the kicker impedance, a detail simulation studies were done in order to determine realistic machine parameters to suppress the beam instability. The simulation results were found to be very consistent with measurements to successfully accomplish 1 MW beam power. The simulation and beam study results in detail are presented in this paper.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR003  
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MOPOW048 Development of the LCLS-II Optics Design undulator, linac, electron, optics 820
 
  • Y. Nosochkov, P. Emma, T.O. Raubenheimer, M. Woodley
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by the Department of Energy Contract DE-AC02-76SF00515.
The LCLS-II is a high repetition rate, high average brightness free-electron laser (FEL) under construction at the SLAC National Accelerator Laboratory. The LCLS-II will include new major components: a high repetition-rate injector, a superconducting, CW (continuous wave), 4-GeV linac with a bunch compressor system, a 3-way beam spreader, with independent hard X-ray (HXR) and soft X-ray (SXR) FEL undulators. The design is based on the existing SLAC facilities, including the LCLS linac and beam transport lines. The new SXR line will utilize a variable-gap undulator sharing the same tunnel with the new HXR horizontal-gap vertically polarizing undulator that will replace the existing LCLS undulator. We describe the current state of the electron optics design and the latest developments. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW048  
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MOPOW055 Injection Using a Non-linear Kicker Located in the Existing Injection Straight at Diamond Storage Ring injection, septum, storage-ring, optics 840
 
  • B. Singh, M. Apollonio, R. Bartolini, I.P.S. Martin
    DLS, Oxfordshire, United Kingdom
  • A. Alekou, R. Bartolini, T. Pulampong
    JAI, Oxford, United Kingdom
  
  Injection studies using a non-linear kicker for the Diamond storage ring have been carried out previously*. These studies have been recently extended to investigate whether the non-linear kicker can be located in the injection straight downstream of the septum and outside the existing dipole kicker bump. If so, injection with a non-linear kicker becomes independent of the optics used, making it suitable for use in both standard and low alpha mode. With this configuration, the existing injection scheme could also be left in place, leaving open the possibility to study both schemes in situ before potentially removing the existing dipole kickers at a later date. In order to operate with the non-linear kicker, the injected beam needs to exit the transfer line at an angle of 3mrad; this has been successfully demonstrated during machine development time. The concept and feasibility studies of this scheme are presented in this paper.
* T. Pulampong, et al., Proc. IPAC 2013, Shanghai, WEPWA065, (2013) 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW055  
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TUPMR008 Simulation of Ion Beam under Coherent Electron Cooling ion, simulation, electron, FEL 1243
 
  • G. Wang, M. Blaskiewicz, V. Litvinenko
    BNL, Upton, Long Island, New York, USA
  • V. Litvinenko
    Stony Brook University, Stony Brook, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The proof of coherent electron cooling (CeC) principle experiment is currently under commissioning and it is essential to have the tools to predict the influences of cooling electrons on a circulating ion bunch. Recently, we have developed a simulation code to track the evolution of an ion bunch under the influences of both CeC and Intra-beam scattering (IBS). In this paper, we will first show the results of benchmarking the code with numerical solutions of Fokker-Planck equation and then present the simulation results for the proof of CeC principle experiment. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR008  
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TUPMR046 Sources of Emittance Growth at the CERN PS Booster to PS Transfer emittance, injection, optics, betatron 1352
 
  • W. Bartmann, J.L. Abelleira, F. Burkart, B. Goddard, J. Jentzsch, R. Ostojić
    CERN, Geneva, Switzerland
  
  The CERN PS Booster (PSB) has four vertically stacked rings. After extraction from each ring, the bunches are recombined in two stages, comprising septum and kicker systems, such that the accumulated bunch train is injected through a single line into the PS. Bunches from the four rings go through a different number of vertical bends, which leads to differences in the betatron and dispersion functions due to edge focussing. The fast pulsed systems at PSB extraction, recombination and PS injection lead to systematic errors of delivery precision at the injection point. These error sources are quantified in terms of emittance growth and particle loss. Mitigations to reduce the overall emittance growth at the PSB to PS transfer within the LHC injectors upgrade are presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR046  
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TUPMR047 Conceptual Design Considerations for the 50 TeV FCC Beam Dump Insertion extraction, collimation, septum, optics 1356
 
  • F. Burkart, M.G. Atanasov, W. Bartmann, B. Goddard, T. Kramer, A. Lechner, A. Sanz Ull, D. Schulte, L.S. Stoel
    CERN, Geneva, Switzerland
  • D. Barna
    University of Tokyo, Tokyo, Japan
  
  Safely extracting and absorbing the 50 TeV proton beams of the FCC-hh collider will be a major challenge. Two extended straight sections (ESS) are dedicated to beam dumping system and collimation. The beam dumping system will fast-extract the beam and transport it to an external absorber, while the collimation system will protect the superconducting accelerator components installed further downstream. The high stored beam energy of about 8.5 GJ per beam means that machine protection considerations will severely constrain the functional design of the ESS and the beam dump line geometry, in addition to dominating the performance specifications of the main sub-systems like kickers and absorber blocks. The general features, including concept choice, optics in the ESS and beam dump line, passive protection devices, layout and integration are described and discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR047  
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TUPMR048 SPS Injection and Beam Quality for LHC Heavy Ions With 150 ns Kicker Rise Time injection, ion, damping, proton 1360
 
  • B. Goddard, E. Carlier, L. Ducimetière, G. Kotzian, J.A. Uythoven
    CERN, Geneva, Switzerland
  • F.M. Velotti
    EPFL, Lausanne, Switzerland
  
  As part of the LHC Injectors Upgrade project for LHC heavy ions, the SPS injection kicker system rise time needs reduction below its present 225 ns. One technically challenging option under consideration is the addition of fast Pulse Forming Lines in parallel to the existing Pulse Forming Networks for the 12 kicker magnets MKP-S, targeting a system field rise time of 100 ns. An alternative option is to optimise the system to approach the existing individual magnet field rise time (2-98%) of 150 ns. This would still significantly increase the number of colliding bunches in LHC while minimising the cost and effort of the system upgrade. The observed characteristics of the present system are described, compared to the expected system rise time, together with results of simulations and measurements with 175 and 150 ns injection batch spacing. The expected beam quality at injection into LHC is quantified, with the emittance growth and simulated tail population taking into account expected jitter and synchronisation errors, damper performance and SPS non-linear optics behavior. The outlook for deployment is discussed, with the implications for LHC operation and HL-LHC performance.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR048  
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TUPMR049 Feasibility Study of the PS Injection for 2 GeV LIU Beams with an Upgraded KFA-45 Injection Kicker System Operating in Short Circuit Mode simulation, injection, flattop, operation 1363
 
  • T. Kramer, W. Bartmann, J.C.C.M. Borburgh, L. Ducimetière, L.M.C. Feliciano, A. Ferrero Colomo, B. Goddard, L. Sermeus
    CERN, Geneva, Switzerland
  
  Under the scope of the LIU project the CERN PS Booster to PS beam transfer will be modified to match the requirements for the future 2 GeV beams. This paper describes the evaluation of the proposed upgrade of the PS injection kicker. Different schemes of an injection for LIU beams into the PS have been outlined in the past already under the aspect of individual transfer kicker rise and fall time performances. Homogeneous rise and fall time requirements in the whole PSB to PS transfer chain have been established which allowed to consider an upgrade option of the present injection kicker system operated in short circuit mode. The challenging pulse quality constraints require an improvement of the flat top and post pulse ripples. Both operation modes, terminated and short circuit mode are analysed and analogue circuit simulations for the present and upgraded system are outlined. Recent measurements on the installed kickers are presented and analysed together with the simulation data. First measurements verifying the performance of upgrade options have been taken during the last end of the year stop. The paper concludes with an upgrade plan and a brief overview of implementation risks.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR049  
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TUPMR050 Upgrades to the SPS-to-LHC Transfer Line Beam Stoppers for the LHC High-Luminosity Era extraction, proton, simulation, brightness 1367
 
  • V. Kain, R. Esposito, M.A. Fraser, B. Goddard, M. Meddahi, A. Perillo Marcone, G.E. Steele, F.M. Velotti
    CERN, Geneva, Switzerland
  
  Each of the 3 km long transfer lines between the SPS and the LHC is equipped with two beam stoppers (TEDs), one at the beginning of the line and one close to the LHC injection point, which need to absorb the full transferred beam. The beam stoppers are used for setting up the SPS extractions and transfer lines with beam without having to inject into the LHC. Energy deposition and thermo-mechanical simulations have, however, shown that the TEDs will not be robust enough to safely absorb the high intensity beams foreseen for the high-luminosity LHC era. This paper will summarize the simulation results and limitations for upgrading the beam stoppers. An outline of the hardware upgrade strategy for the TEDs together with modifications to the SPS extraction interlock system to enforce intensity limitations for beam on the beam stoppers will be given.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR050  
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TUPMY036 Drive Generation and Propagation Studies for the Two Beam Acceleration Experiment at the Argonne Wakefield Accelerator laser, simulation, power-supply, wakefield 1629
 
  • N.R. Neveu, M.E. Conde, D.S. Doran, W. Gai, G. Ha, C.-J. Jing, W. Liu, J.G. Power, D. Wang, C. Whiteford, E.E. Wisniewski
    ANL, Argonne, Illinois, USA
  • S.P. Antipov, C.-J. Jing
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • G. Ha
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • N.R. Neveu
    IIT, Chicago, Illinois, USA
  • D. Wang
    TUB, Beijing, People's Republic of China
  
  Funding: Work supported by by the U.S. Department of Energy under contract No. DE-AC02-06CH11357.
Simplified staging in a two beam accelerator (TBA) has been accomplished at the Argonne Wakefield Accelerator (AWA) facility. This layout consists of a drive beamline and witness beamline operating synchronously. The drive photoinjector linac produces a 70 MeV drive bunch train of eight electron bunches (charge per bunch between 5-40 nC) that pass through decelerating structures in each TBA stage. The witness linac produces an 8 MeV witness bunch that passes through the accelerating structures in each TBA stage. Recent effort has been focused on improving the uniformity of the UV laser pulses that generate the bunch trains. Current work at the AWA is focused on the transition from simplified staging to full staging. A kicker will be designed and installed to direct bunch trains to one TBA stage only. Preliminary calculations and simulation results are presented. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMY036  
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WEOAA02 On-axis Beam Accumulation Enabled by Phase Adjustment of a Double-frequency RF System for Diffraction-limited Storage Rings injection, lattice, synchrotron, storage-ring 2032
 
  • G. Xu, J. Chen, Z. Duan, J. Qiu
    IHEP, Beijing, People's Republic of China
  
  Funding: Work supported by NSFC (Y4113G005C)
Future synchrotron light sources aim to achieve ultra- low emittances on both transverse planes, approaching or even reaching the diffraction limit of X-ray photon energies. These diffraction-limited storage rings (DLSRs) feature very strong lattice nonlinearities and thus very small dynamic aperture, which exclude off-axis injection schemes. In this paper, we propose a longitudinal on-axis injection scheme, which is based on a double-frequency RF system and in- dependently adjustment of the RF phase of each cavity to enable RF gymnastics. Such a scheme looks feasible with the state-of-art technology of fast injection kicker. Compari- son with other on-axis injection schemes is also discussed. 		 
slides icon Slides WEOAA02 [1.712 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA02  
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WEPMW011 Stable Spin Direction Investigations in RHIC extraction, emittance, septum, injection 2442
 
  • F. Méot, H. Huang, N. Tsoupas
    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.
Beam and spin dynamics investigations are part of the preparations and studies regarding RHIC collider runs, they are part as well of the efforts dedicated to improving stored beam polarization, and in view of the eRHIC EIC project. Some recent studies and their outcomes are discussed. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW011  
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WEPMY010 Considerations for a Drive Beam Scheme for a Plasma Wakefield Linear Collider plasma, collider, linac, lattice 2565
 
  • J. Pfingstner, E. Adli, C.A. Lindstrøm
    University of Oslo, Oslo, Norway
  • E. Marín, D. Schulte
    CERN, Geneva, Switzerland
  
  The potential for high average gradients makes plasma wakefield acceleration (PWFA) an attracting option for future linear colliders. For a beam-driven PWFA collider a sequence of cells has to be supplied with synchronised drive beam bunches. This paper is concerned with the generation, transport and distribution of these drive beam bunches in a so-called drive beam complex for a 3 TeV collider. Based on earlier concepts, several modifications are suggested. The new design includes a superconducting linac and an optimised bunch delay system with a tree structure. To verify the feasibility for the overall complex, a lattice design and tracking studies for the critical bending arc subsystem are presented. Also the feasibility of a compact bunch separation system is shown. The result of these efforts is a drive beam complex that is optimised for construction cost and power efficiency that favours unified lattice solutions.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY010  
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WEPOR001 Beam Studies with a New Longitudinal Feedback System at the ANKA Storage Ring feedback, injection, synchrotron, storage-ring 2658
 
  • E. Blomley, A.-S. Müller, M. Schedler
    KIT, Karlsruhe, Germany
  
  With the now fully commissioned longitudinal feedback system at the ANKA Storage Ring - in addition to the already operational transverse feedback system - the stability throughout the injection process was increased considerably. This opened up the possibility to investigate beam dynamics and limitations during injection more systematically. This paper presents the results of these studies, an overview of the limiting parameters and discusses possible approaches to increase the efficiency of the injection.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR001  
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WEPOR006 Demonstration of CLIC Level Phase Stability using a High Bandwidth, Low Latency Drive Beam Phase Feedforward System at the CLIC Test Facility CTF3 hardware, optics, simulation, electronics 2673
 
  • J. Roberts, P. Burrows, G.B. Christian, C. Perry
    JAI, Oxford, United Kingdom
  • A. Andersson, R. Corsini, P.K. Skowroński
    CERN, Geneva, Switzerland
  • A. Ghigo, F. Marcellini
    INFN/LNF, Frascati (Roma), Italy
  
  Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no.~227579.
The CLIC acceleration scheme, in which the RF power used to accelerate the main high energy beam is extracted from a second high intensity but low energy beam, places strict requirements on the phase stability of the power producing drive beam. To limit luminosity loss caused by energy jitter leading to emittance growth in the final focus to below 1%, 0.2 degrees of 12 GHz, or 50 fs, drive beam phase stability is needed. A low-latency phase feedforward correction with bandwidth above 17.5 MHz will be used to reduce the drive beam phase jitter to this level. The proposed scheme corrects the phase using fast electromagnetic kickers to vary the path length in a chicane prior to the drive beam power extraction. A prototype of this system has been installed at the CLIC test facility CTF3 to prove its feasibility. The latest results from the system are presented, demonstrating phase stabilisation in agreement with simulations given the beam conditions and power of the kicker amplifiers. Necessary improvements in the phase monitor performance and optics corrections made to remove the phase-energy dependence via R56 in order to achieve this level of stability are also discussed. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR006  
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WEPOR009 Intra-beam IP Feedback Studies for the 380 GeV CLIC Beam Delivery System luminosity, feedback, ground-motion, simulation 2683
 
  • R.M. Bodenstein, P. Burrows, J. Snuverink
    JAI, Oxford, United Kingdom
  • F. Plassard
    CERN, Geneva, Switzerland
  
  In its currently-envisaged initial stage, the Compact Linear Collider (CLIC) will collide beams with a 380 GeV center of mass energy. To maintain the luminosity within a few percent of the design value, beam stability at the interaction point (IP) must be controlled at the sub-nanometer level. To help achieve such control, use of an intra-pulse IP feedback system is planned. With CLIC's very short bunch spacing of 0.5 ns, and nominal pulse duration of 176 ns, this feedback system presents a significant technical challenge. Furthermore, as part of a study to optimize the design of the beam delivery system (BDS), several L* configurations have been studied. In this paper, we will review the IP feedback simulations for the 380 GeV machine for two L* configurations, and compare luminosity recovery performance with that of the original L* configuration in the 3 TeV machine.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR009  
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WEPOR056 Development of a Cw Solid State Amplifier for the Longitudinal Feedback System of Bepcii feedback, detector, controls, HOM 2796
 
  • S. An, Z. Bowen
    PLAI, Nanjing, People's Republic of China
  • J.L. Linling
    ADS, Jiangsu Province, People's Republic of China
  • J.H. Yue
    IHEP, Beijing, People's Republic of China
  • L. Zhang
    Chang'an University, Chang'an, People's Republic of China
  
  A Solid State Amplifier (SSA) has been developed for testing beam feedback system of the BEPCII of the Institute of High Energy Physics (IHEP), CAS. The output power of the SSA is 100 W with a CW frequency range from 1000 MHz to 1250 MHz. After three generations development, the SSA has become a professional power source. The paper has introduced the development of the SSA and the skills used in the SSA.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR056  
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WEPOW001 Sirius Status Report storage-ring, booster, vacuum, dipole 2811
 
  • A.R.D. Rodrigues, F.C. Arroyo, O.R. Bagnato, J.F. Citadini, R.H.A. Farias, J.G.R.S. Franco, L. Liu, S.R. Marques, R.T. Neuenschwander, C. Rodrigues, F. Rodrigues, R.M. Seraphim, O.H.V. Silva
    LNLS, Campinas, Brazil
  
  Sirius is a Synchrotron Light Source Facility based on a 4th generation low emittance storage ring that is presently under construction in Campinas, Brazil. During the last year, accelerator activities concentrated on R&D of the various subsystem components. However, the number of components under production or already delivered is also increasing according to planning. The building construction started in the beginning of 2015 and machine commissioning is expected to start mid 2018. In this paper we report on the present status of the project with emphasis on the last year activities.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW001  
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WEPOW052 Multimodal Interaction in the ALS Longitudinal Feedback Kicker RF Cavity cavity, feedback, resonance, impedance 2965
 
  • S. De Santis, K.M. Baptiste, J.M. Byrd, S. Kwiatkowski, T.H. Luo, E.R. Sanmateo, C. Steier, C.A. Swenson
    LBNL, Berkeley, California, USA
  • F. Marcellini
    PSI, Villigen PSI, Switzerland
  
  Funding: The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
RF cavities are essential components in particle accelerators not only for beam acceleration, but also for control purposes (bunch lengthening/shortening, deflecting and crabbing, transverse and longitudinal kickers) and for beam diagnostics (BPM). Normally, only a single resonating mode is actively used, although other modes can be excited by the circulating beam. Cavities used as feedback longitudinal kickers are designed with an axial mode which, appropriately excited, provides a kick to the circulating bunches for maintaining beam stability. To provide the necessary bandwidth this mode has to be strongly damped resulting in quality factors of just a few units. In the longitudinal feedback kicker cavity just installed on the ALS we have detected a second axial mode which, although a few hundreds of MHz below the 1.4 GHz design mode, is also strongly damped and has a shunt impedance high enough to be appreciably excited by the feedback amplifier coupling to the first mode. In this paper we show bench measurements on the cavity and with beam during its commissioning and discuss the interaction of the two modes resulting in a modulation of shunt impedance and phase response. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW052  
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WEPOY021 Nonlinear Phase Distortion in a Ti:Sapphire Optical Amplifier for Optical Stochastic Cooling undulator, laser, radiation, pick-up 3024
 
  • M.B. Andorf, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • V.A. Lebedev, P. Piot, J. Ruan
    Fermilab, Batavia, Illinois, USA
  
  Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359.
Optical Stochastic Cooling (OSC) has been considered for future high-luminosity colliders as it offers much faster cooling time in comparison to the micro-wave stochastic cooling. The OSC technique relies on collecting and amplifying a broadband optical signal from a pickup undulator and feeding the amplified signal back to the beam. It creates a corrective kick in a kicker undulator. Owing to its superb gain qualities and broadband amplification features, Titanium:Sapphire medium has been considered as a gain medium for the optical amplifier (OA) needed in the OSC*. A limiting factor for any OA used in OSC is the possibility of nonlinear phase distortions. In this paper we experimentally measure phase distortions by inserting a single-pass OA into one leg of a Mach-Zehnder interferometer. The measurement results are used to estimate the reduction of the corrective kick a particle would receive due to these phase distortions in the kicker undulator.
* A. Zholents, and M. Zolotorev. Proc. PAC'97, 1805 (1998). 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY021  
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WEPOY022 Light Optics for Optical Stochastic Cooling undulator, radiation, electron, pick-up 3028
 
  • M.B. Andorf, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • V.A. Lebedev, P. Piot, J. Ruan
    Fermilab, Batavia, Illinois, USA
  
  Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359.
In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction*. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material.
* V. Lebedev, et al., Proc. COOL'15 (in press, 2015).
 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY022  
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THPMB030 Operation Improvement by Tuning of Storage Ring at PLS-II injection, operation, storage-ring, linac 3297
 
  • I. Hwang, M. Kim, T.-Y. Lee, C.D. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  After upgrade of the pohang light source (PLS-II), several problems reduced the quality of the top-up operation. Unbalance of the injection kicker system and it's lack of control had limited the efficiency of the injection from the linac to the storage ring. We tuned the storage ring to improve the injection efficiency and to stabilize the orbit during the injection.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB030  
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THPMB037 Comparing the Transverse Dynamics of the ESS Linac Simulator and the Spallation Neutron Source Linac linac, neutron, controls, space-charge 3314
 
  • E. Laface, Y.I. Levinsen
    ESS, Lund, Sweden
  • T.A. Pelaia II
    ORNL, Oak Ridge, Tennessee, USA
  
  The ESS Linac Simulator (ELS) is the model that will be used at the European Spallation Source ERIC in Lund, Sweden, to simulate the transport of the beam envelope during operations. On August 12th 2015, we had the opportunity to use two hours of beam time in the linac of the Spallation Neutron Source in Oak Ridge to benchmark ELS. In this paper we present the results of the transverse dynamics measurements. Such measurements are obtained upon kicking the beam in the medium-energy beam transport (MEBT) and measuring the effect of the oscillation of the beam centroid in 58 beam position monitors (BPMs). The ELS model and these measurements are in agreement with an average discrepancy of 4% in the superconducting section of the accelerator.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB037  
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THPMR011 Injection Dynamics for Sirius Using a Nonlinear Kicker injection, storage-ring, booster, accumulation 3406
 
  • L. Liu, X.R. Resende, A.R.D. Rodrigues, F. H. de Sá
    LNLS, Campinas, Brazil
  
  The concept of injection using a single nonlinear kicker has been proposed and tested in several existing storage rings with reduction in the stored beam oscillations during the accumulation process. Despite the good results, this scheme has not yet been adopted for routine operation in these machines due to the reduced injection efficiency. The main cause for reduction in efficiency is precisely the nonlinearity of the kick at the injected beam position and the generally large injected beam size. In this paper we study the injection dynamics in the Sirius storage ring where beam accumulation is based only on the use of a nonlinear kicker. The whole injection system has been optimized from the start for high injection efficiency.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR011  
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THPMW019 Concept and Design of the Injection Kicker System for the FAIR SIS100 Synchrotron vacuum, operation, ion, pulsed-power 3582
 
  • I.J. Petzenhauser, U. Blell, P.J. Spiller
    GSI, Darmstadt, Germany
  • L.O. Baandrup, H. Bach, N. Hauge, K.F. Laurberg
    Danfysik A/S, Taastrup, Denmark
  • G. Blokesch, M. Osemann
    Ampegon PPT GmbH, Dortmund, Germany
  
  The SIS100 synchrotron at GSI, Germany is designed for acceleration of protons and ions. For the injection into the synchrotron a kicker magnet system, which consists of 6 ferrite kicker magnet modules, installed in one vacuum tank with a required vacuum quality better than 10-9 Pa, will be needed. The magnetic field should be 118 mT in a 65 mm gap. These kicker magnet modules will be supplied with 6 separate pulser circuits. Each pulser has to produce a pulse current of up to 7 kA at a PFL (pulse forming line) voltage of 80kV at an impedance of 5.7 Ohm. The rise time has to be 130 ns and the variable pulse length is between 0.5 to 2.0 μs. The design concept for this kicker system from Ampegon PPT and DANFYSIK and the specific challenges will be described.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW019  
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THPMW020 Solid-state Compact Kicker Pulsar using Strip-line Type Blumlein with SIC-MOSFET in Spring-8 high-voltage, impedance, operation, storage-ring 3585
 
  • C. Mitsuda, T. Honiden, K. Kobayashi, T. Kobayashi, S. Sasaki
    JASRI/SPring-8, Hyogo-ken, Japan
  • N. Sekine
    Sekine Electric Works Co. Ltd, Osaka, Japan
  
  In the case of handling the electron beam by bunch-by-bunch and turn-by-turn with a kicker at the SPring-8, the performances required to a pulsar are short pulse width (<40ns) and high repetitions (>208kHz). In order to achieve these specifications, the short pulsed high voltage output and the utilization of the solid-state switch is necessary for an inductance load. In order to suppress the supplied voltage as low as as possible, it is an important feature to realize the extremely small-sized pulsar to be set near the kicker. On the basis of the experiences in developing the solid-state pulsar of 400ns/2kV using Si-MOSFET*, combination of the SiC-MOSFET and the strip-line type Blumlein pulse forming network (BPFN) was applied to the prototype driver to achieve a shorter pulse and higher power than Si-type driver. The completed pulsar accomplished a compact size (external dimensions; 300(H)x400(W)x400(D)mm). Furthermore, the targeted short-pulsed high voltage output of 123ns/12kV was obtained by 6 BPFNs serial connection to the load inductance of 800 nH. The BPFN detailed design to enable the compact size, high reliability and stability at high repetitions will be reported.
* C.Mitsuda et al., Proc. of IPAC2013, MOPAWA003 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW020  
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THPMW021 Performance of a Compensation Kicker Magnet for J-PARC Main Ring timing, injection, pick-up, proton 3588
 
  • T. Sugimoto, K. Ishii, H. Matsumoto, T. Shibata
    KEK, Ibaraki, Japan
  • K. Fan
    HUST, Wuhan, People's Republic of China
  
  Four lumped-type kicker magnets have been equipped in the J-PARC MR (Main Ring) to inject 8 proton bunches. To increase beam power, the bunch length will be increased up to 350 ns that will restricts the rise time of the injection kicker to be less than 250 ns. We have already developed a method to improve the rising time to 200 ns*. However, two reflection pulses are appeared at the waveform tail, which will kick the circulating bunches and induce coherent oscillation leading to beam loss. To compensate reflection pulses, we decide to install two new lumped-type kicker magnets, which are excited independently making operation flexible. A ceramic vacuum duct with TiN coating is inserted in the compensation kickers. Magnetic field measurement and coupling impedance measurement have been carried. In this paper, the results of both these measurements and performance study using proton beam will be discussed.
* T.Sugimot et.al, "Upgrade of the Injection Kicker System for J-PARC Main Ring", MOPME069, IPAC14, Dresden, Germany, 2014. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW021  
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THPMW028 High Voltage Performance of Surface Coatings on Alumina Insulators high-voltage, injection, vacuum, impedance 3603
 
  • A. Adraktas, M.J. Barnes, H.A. Day, L. Ducimetière
    CERN, Geneva, Switzerland
  
  Alumina insulators and dielectrics are required for a variety of applications in particle accelerators. Their use in high voltage devices, both pulsed and DC, is well established as both insulation and mechanical support. In accelerator equipment the alumina is usually used in ultra-high vacuum and hence charge accumulation can be an issue, especially when the alumina is near to the beam. To address challenges regarding surface flashover and high secondary electron yield in high intensity accelerators, surface treatments and coatings are being considered. This paper presents predictions of the influence of surface coatings, on alumina insulators, upon electric field.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW028  
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THPMW029 Feasibility Study of the Fast SPS Ion Injection Kicker System simulation, injection, ion, flattop 3607
 
  • A. Ferrero Colomo, P. Burkel, D. Comte, L. Ducimetière, T. Kramer, V. Senaj, L. Sermeus, F.M. Velotti
    CERN, Geneva, Switzerland
  
  As part of the upgrade project for ions the rise time of the injection kicker system into the SPS needs to be improved. The changes being studied include the addition of a fast Pulse Forming Line parallel to the existing Pulse Forming Network for the fast kicker magnets MKP-S. With the PFL an improved magnetic field rise time of 100 ns is targeted. Two different configuration utilizing a 2nd thyratron or two fast diode stacks have been outlined in the past. This paper presents the recent progress on the analogue circuit simulations for both options as well as measurements carried out on a test system. Modelling, optimization and simulation of the entire system with diodes and a second configuration with two thyratron switches are outlined. Measurement results are given and the feasibility of the upgrade is discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW029  
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THPMW030 Studies of Impedance-related Improvements of the SPS Injection Kicker System impedance, simulation, coupling, vacuum 3611
 
  • M.J. Barnes, A. Adraktas, M.S. Beck, G. Bregliozzi, H.A. Day, L. Ducimetière, J.A. Ferreira Somoza, B. Goddard, T. Kramer, C. Pasquino, G. Rumolo, B. Salvant, L. Sermeus, J.A. Uythoven, L. Vega Cid, W.J.M. Weterings, C. Zannini
    CERN, Geneva, Switzerland
  • F.M. Velotti
    EPFL, Lausanne, Switzerland
  
  The injection kicker system for the SPS consists of sixteen magnets housed in a total of four vacuum tanks. The kicker magnets in one tank have recently limited operation of the SPS with high-intensity beam: this is due to both beam induced heating in the ferrite yoke of the kicker magnets and abnormally high pressure in the vacuum tank. Furthermore, operation with the higher intensity beams needed in the future for HL-LHC is expected to exacerbate these problems. Hence studies of the longitudinal beam coupling impedance of the kicker magnets have been carried out to investigate effective methods to shield the ferrite yoke from the circulating beam. The shielding must not compromise the field quality or high voltage behaviour of the kicker magnets and should not significantly reduce the beam aperture: results of these studies, together with measurements, are presented. In addition results of tests to identify the causes of abnormal outgassing are presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW030  
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THPMW031 Current and Future Beam Thermal Behaviour of the LHC Injection Kicker Magnet impedance, injection, simulation, coupling 3615
 
  • H.A. Day, M.J. Barnes, L. Ducimetière, L. Vega Cid, W.J.M. Weterings
    CERN, Geneva, Switzerland
  
  During Run 1 of the LHC the injection kicker magnets caused occasional operational delays due to beam induced heating with high bunch intensity and short bunch lengths. Significant upgrades were carried out to the injection kicker magnets during long shutdown 1, including a new design of beam screen to reduce the beam induced heating. Nevertheless these kicker magnets may limit the performance of HL-LHC unless additional, mitigating, measures are taken. Hence extensive simulations have been carried out to predict the distribution of the beam induced power deposition within the magnet and detailed thermal analyses carried out to predict the temperature profiles. To benchmark the simulations the predicted temperatures are compared with observables in the LHC. This paper reports on observations of the thermal behaviour of the magnet during run 2 of the LHC, with 25ns beam. In addition the measurement data is used to extrapolate temperature rise for the beam parameters expected for high-luminosity LHC.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW031  
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THPMW032 Measurements on Magnetic Cores for Inductive Adders with Ultra-Flat Output Pulses for CLIC DR Kickers flattop, damping, collider, emittance 3619
 
  • J. Holma, M.J. Barnes, L. Ducimetière
    CERN, Geneva, Switzerland
  
  The CLIC study is investigating the technical feasibility of an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the DR kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the DR extraction kickers call for 160 ns duration flattop pulses of ±12.5 kV, with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meet the specifications. Two five layer, 3.5 kV, prototype inductive adders have been built at CERN, and used to test passive and active analogue modulation methods to compensate droop and ripple of the output pulses. Recently, magnetic core materials and full-scale magnetic cores have been evaluated for the 12.5 kV prototype inductive adders. These results are presented in this paper and conclusions are drawn concerning the design of the full-scale prototypes.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW032  
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THPMW033 Operational Experience of the Upgraded LHC Injection Kicker Magnets injection, vacuum, operation, impedance 3623
 
  • M.J. Barnes, A. Adraktas, G. Bregliozzi, S. Calatroni, H.A. Day, L. Ducimetière, B. Goddard, V. Gomes Namora, V. Mertens, B. Salvant, J.A. Uythoven, L. Vega Cid, W.J.M. Weterings, C. Yin Vallgren
    CERN, Geneva, Switzerland
  
  During Run 1 of the LHC the injection kicker magnets caused occasional operational delays due to beam induced heating with high bunch intensity and short bunch lengths. In addition, sometimes there were also sporadic issues with microscopic unidentified falling objects, vacuum activity and electrical flashover of the injection kickers. An extensive program of studies was launched and significant upgrades were carried out during long shutdown 1. These upgrades include a new design of a beam screen to both reduce the beam coupling impedance of the kicker magnet, and to significantly reduce the electric field associated with the screen conductors, hence decreasing the probability of electrical breakdown in this region. In addition new cleaning procedures were implemented and equipment adjacent to the injection kickers and various vacuum components were modified. This paper presents operational experience of the injection kicker magnets during Run 2 of the LHC and assesses the effectiveness of the various upgrades.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW033  
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THPMW034 Review on the Effects of Characteristic Impedance Mismatching in a Stripline Kicker impedance, extraction, damping, emittance 3627
 
  • C. Belver-Aguilar, M.J. Barnes, L. Ducimetière
    CERN, Geneva, Switzerland
  
  A stripline kicker operates as two coupled transmission lines, with two TEM operating modes, known as odd and even modes. The characteristic impedance of these two modes is generally different, both only tend to the same value either when the electrodes are widely separated or when the electrodes are very close to the beam pipe wall. In all other cases, the even mode characteristic impedance is always higher than the odd mode characteristic impedance. The specifications required for a kicker operating in a low emittance ring are usually very challenging. In this situation it is desirable to match the even mode characteristic impedance of the striplines to the resistance of their termination. However a mismatched odd mode impedance can significantly influence the striplines performance. This paper presents predictions for the influence of the odd mode characteristic impedance upon the contribution of each field component, electric and magnetic, to the deflection angle. In addition, the variation of the characteristic impedance and field homogeneity with frequency are presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW034  
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THPMW035 Considerations on an Upgrade Possibility of the LHC Beam Dump Kicker System extraction, operation, quadrupole, optics 3631
 
  • M.A. Fraser, W. Bartmann, C. Bracco, L. Ducimetière, B. Goddard, T. Kramer, V. Senaj
    CERN, Geneva, Switzerland
  
  The LHC Beam Dump System (LBDS) is designed to safely dispose the circulating beams over a wide range of energy from 450 GeV up to 7 TeV, where the maximum stored energy is 362 MJ per beam. One of the most critical components of the LBDS are the extraction kickers that must reliably switch on within the 3 us particle-free abort gap. To ensure this functionality, even in the event of a power-cut, the power generator capacitors remain charged and hence the Gate Turn-Off (GTO) switch stack has to hold the full voltage throughout beam operation. The increase of the LHC collision energy to 13 TeV has increased the voltage levels at the GTO stacks and during re-commissioning an increased rate of high-voltage (HV) related issues at the level of the GTO stack was observed. Different solutions have been analysed and an improved GTO stack will be implemented. This paper also outlines the benefit of adding more kicker magnets to improve the voltage hold off issues and to improve the tolerance to missing kickers during extraction.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW035  
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THPMW038 Prototyping of the ALS-U Fast Kickers impedance, coupling, vacuum, injection 3637
 
  • G.C. Pappas, S. De Santis, J.-Y. Jung, T.H. Luo, C. Steier, C.A. Swenson, W.L. Waldron
    LBNL, Berkeley, California, USA
  
  Prototyping of major components for the ALS-U kickers is in progress. A tapered stripline kicker has been built for installation and testing in the ALS, and multiple modulator options to meet the fast rise time required for swap out injection have been considered. High voltage feedthroughs that are matched into the multi GHz range are also being studied.
* Pappas et al., "Fast Kicker Systems for ALS-U", Proc. of IPAC'14, Dresden, Germany, MOPME083. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW038  
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THPMW042 Overview of Driver Technologies for Nanosecond TEM Kickers impedance, operation, controls, injection 3645
 
  • A.K. Krasnykh
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported in part by US Department of Energy under contract DE-AC02-76SF00515 and in part by US Department of Energy under contract DE-AC02-06CH11357
Overview of modern methods, circuits, and practical realizations for multi MW peak power pulsers will be presented. All used pulser components are manufactured by the US national industry and they are available for design and pulser fabrication. Two concepts will be discussed: (1) an approach is based on assistance of a nonlinear transmission line with ferromagnetic media and (2) an approach is based on assistance of special diodes which are working in a specific mode of operation. In both approaches the nonlinear characteristic of switching media (ferromagnetic and solid state plasma) are employed in final stage of the pulser to form the multi MW level nanosecond pulses. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW042  
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THPMW043 Observation of Beam-induced Abort Kicker Ferrite Heating in RHIC vacuum, quadrupole, proton, impedance 3648
 
  • C. Montag, L. Ahrens, K.A. Drees, H. Hahn, J.-L. Mi, C. Pai, J. Sandberg, T.C. Shrey, P. Thieberger, 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.
During the FY 2013 RHIC polarized proton run, deterioration of the abort kicker system was observed. The reduced kicks resulted in quenching the superconducting quadrupole Q4 downstream of the beam dump. Frequent re-tuning of the modulator wave form temporarily mitigated the effect, which worsened during the course of the run. Beam-induced heating of the kicker ferrites was evenutally identified as the root cause of this behavior. We report our observations and discuss modifications to the kickers. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW043  
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THPMY019 LHC Injection Protection Devices, Thermo-mechanical Studies through the Design Phase injection, operation, proton, impedance 3698
 
  • I. Lamas Garcia, N. Biancacci, G. Bregliozzi, M. Calviani, M.I. Frankl, L. Gentini, S.S. Gilardoni, A. Lechner, A. Perillo-Marcone, B. Salvant, N.V. Shetty, J.A. Uythoven
    CERN, Geneva, Switzerland
  
  The TDI is a beam intercepting device installed on the two injection lines of the LHC. Its function is to protect the superconducting machine elements during injection in the case of a malfunction of the injection kickers. The TDIS, which will replace the TDI, is foreseen to be installed for high luminosity operation. Due to the higher bunch intensities and smaller beam emittances expected, and following the operational experiences of the TDI, a complete revision of the design of the jaws must be performed, with a main focus on the material selection. Furthermore, the new TDIS will also improve the TDI reliability by means of a robust design of the jaw positioning mechanism, the efficiency of the cooling circuit and by reducing its impedance. A simplified installation procedure and maintenance will also be an important requirement for the new design. This paper introduces the main characteristics of the TDI as LHC injection protection device, showing the needs and requirements for its upgrade. It also discusses the thermo-mechanical simulations that are supporting and guiding the design phase and the material selection, and describes the modifications to be implemented, so far, for this new device.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY019  
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THPOR034 Bunch-by-bunch Position and Angle Stabilisation at ATF based on Sub-micron Resolution Stripline Beam Position Monitors feedback, extraction, operation, linear-collider 3859
 
  • N. Blaskovic Kraljevic, R.M. Bodenstein, T. Bromwich, P. Burrows, G.B. Christian, M.R. Davis, C. Perry, R.L. Ramjiawan
    JAI, Oxford, United Kingdom
  • D.R. Bett
    CERN, Geneva, Switzerland
  
  A low-latency, sub-micron resolution stripline beam position monitoring (BPM) system has been developed and tested with beam at the KEK Accelerator Test Facility (ATF2), where it has been used to drive a beam stabilisation system. The fast analogue front-end signal processor is based on a single-stage radio-frequency down-mixer, with a measured latency of 16 ns and a demonstrated single-pass beam position resolution of below 300 nm using a beam with a bunch charge of approximately 1 nC. The BPM position data are digitised on a digital feedback board which is used to drive a pair of kickers local to the BPMs and nominally orthogonal in phase in closed-loop feedback mode, thus achieving both beam position and angle stabilisation. We report the reduction in jitter as measured at a witness stripline BPM located 30 metres downstream of the feedback system and its propagation to the ATF interaction point.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR034  
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THPOR035 Development of a Low-latency, Micrometre-level Precision, Intra-train Beam Feedback System based on Cavity Beam Position Monitors feedback, cavity, electron, extraction 3862
 
  • N. Blaskovic Kraljevic, R.M. Bodenstein, T. Bromwich, P. Burrows, G.B. Christian, M.R. Davis, C. Perry, R.L. Ramjiawan
    JAI, Oxford, United Kingdom
  • D.R. Bett
    CERN, Geneva, Switzerland
  
  A low-latency, intra-train, beam feedback system utilising a cavity beam position monitor (BPM) has been developed and tested at the final focus of the Accelerator Test Facility (ATF2) at KEK. A low-Q cavity BPM was utilised with custom signal processing electronics, designed for low latency and optimal position resolution, to provide an input beam position signal to the feedback system. A custom stripline kicker and power amplifier, and a digital feedback board, were used to provide beam correction and feedback control, respectively. The system was deployed in single-pass, multi-bunch mode with the aim of demonstrating intra-train beam stabilisation on electron bunches of charge ~1 nC separated in time by c. 220 ns. The system has been used to demonstrate beam stabilisation to below the 75 nm level. Results of the latest beam tests, aimed at even higher performance, will be presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR035  
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THPOR048 Beam Losses at CERNs PS and SPS Measured with Diamond Particle Detectors extraction, detector, septum, injection 3898
 
  • F. Burkart, W. Bartmann, B. Dehning, E. Effinger, M.A. Fraser, B. Goddard, V. Kain, O. Stein
    CERN, Geneva, Switzerland
  • E. Griesmayer
    CIVIDEC Instrumentation, Wien, Austria
  • O. Stein
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  
  Diamond particle detectors have been used in the LHC to measure fast particle losses with a nanosecond time resolution. In addition, these detectors were installed in the PS and the SPS. The detectors are mounted close to the extraction septum of the PS (transfer line to SPS) and the SPS (transfer lines TI2 and TI8 to LHC). Mainly, they monitor the losses occurring during the extraction process but the detectors are also able to measure turn-by-turn losses in the accelerators. In addition, detailed studies concerning losses due to ghost bunches were performed. This paper will describe the installed diamond detector setup, discuss the measurement results and possible loss mitigations.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR048  
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THPOR049 Considerations for the Injection and Extraction Kicker Systems of a 100 TeV Centre-of-Mass FCC-hh Collider extraction, injection, impedance, collider 3901
 
  • T. Kramer, M.J. Barnes, W. Bartmann, F. Burkart, L. Ducimetière, B. Goddard, V. Senaj, T. Stadlbauer, D.G. Woog
    CERN, Geneva, Switzerland
  • D. Barna
    Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary
  
  A 100 TeV center-of-mass energy frontier proton collider in a new tunnel of ~100 km circumference is a central part of CERN's Future Circular Colliders (FCC) design study. One of the major challenges for such a machine will be the beam injection and extraction. This paper outlines the recent developments on the injection and extraction kicker system concepts. For injection the system requirements and progress on a new inductive adder design will be presented together with first considerations on the injection kicker magnets. The extraction kicker system comprises the extraction kickers itself as well as the beam dilution kickers, both of which will be part of the FCC beam dump system and will have to reliably abort proton beams with stored energies in the range of 8 Gigajoule. First concepts for the beam dump kicker magnet and generator as well as for the dilution kicker system are described and its feasibility for an abort gap in the 1 μs range is discussed. The potential implications on the overall machine and other key subsystems are outlined, including requirements on (and from) dilution patterns, interlocking, beam intercepting devices and insertion design.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR049  
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THPOR051 Beam Based Measurements to Check Integrity of LHC Dump Protection Elements extraction, proton, operation, vacuum 3908
 
  • C. Bracco, W. Bartmann, M.A. Fraser, B. Goddard, A. Lechner
    CERN, Geneva, Switzerland
  
  LHC operation is approaching its nominal operating goals and several upgrades are also being prepared to increase the beam intensity and brightness. In case of an asynchronous beam dump at 6.5 - 7 TeV a non-negligible fraction of the stored energy (360 MJ during nominal operation) will be deposited on the protection elements (TCDQ and TCDS) located downstream of the extraction kickers. These elements are designed to protect the machine aperture from the large amplitude particles resulting from the asynchronous dump. A number of checks and measurements with beam have been worked out to verify the integrity of these elements, after a potentially harmful event, without opening the machine vacuum. Details on measurements and simulations performed to evaluate the validity of the proposed method are presented in this paper.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR051  
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THPOR052 A Beam-based Measurement of the LHC Beam Dump Kicker Waveform extraction, simulation, operation, dumping 3911
 
  • M.A. Fraser, W. Bartmann, C. Bracco, E. Carlier, B. Goddard, V. Kain, N. Magnin, J.A. Uythoven, F.M. Velotti
    CERN, Geneva, Switzerland
  
  The increase of the LHC collision energy to 13 TeV after Long Shutdown 1 has doubled the operational energy range of the LHC beam dump system (LBDS) during Run 2. In preparation for the safe operation of the LHC, the waveform of the LBDS extraction kicker was measured using beam-based measurements for the first time during the machine's re-commissioning period. The measurements provide a reference for a more precise synchronisation of the dump system and abort-gap timing, and provide an independent check of the system's calibration. The precision of the beam-based technique allowed the necessary adjustments to the LBDS trigger delays to ensure the synchronous firing of the LBDS at all beam energies up to 6.5 TeV. In this paper the measurement and simulation campaign is described and the performance of the system reported.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR052  
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THPOW032 Experimental Test on the TPS Booster Injection Scheme Exploration and the Associated Bunch Train Analysis injection, booster, septum, operation 4008
 
  • H.-P. Chang, C.L. Chen, C.-S. Fann, K.T. Hsu, S.Y. Hsu, K.-K. Lin, K.L. Tsai
    NSRRC, Hsinchu, Taiwan
  
  In order to explore the tuning range of injection septum and kicker for TPS booster operation, an experimental test on the designed injection scheme has been performed. Tuning of these injection units is based on the top-up operation process for storage ring vacuum cleaning purpose. It is set for a fast beam accumulation in the storage ring where the stored beam variation range is selected for efficient operation consideration. The measurement results of booster beam current variation while tuning of injection septum and kicker are presented. A preliminary analysis concerning the observation of deteriorated phase space acceptance in the TPS booster is given in this report. This study also includes an effort to extend the present available operation bunch train for TPS booster. It shows that the increase of the booster beam current by bunch train tuning indicates an upper bound of about 400 ns.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW032  
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THPOW033 Transient Orbit of Injection in Taiwan Light Source Storage Ring injection, storage-ring, factory, network 4012
 
  • H.C. Chen, H.H. Chen, K.T. Hsu, C.H. Huang, S.J. Huang, C.H. Kuo, A.P. Lee, J.A. Li, Y.K. Lin
    NSRRC, Hsinchu, Taiwan
  
  Top-up operation has been started since many years ago at Taiwan Light Source Storage Ring (SR). For this operation it is important to reduce the beam injections should not excite the oscillation of stored beams. For further reduction of these oscillations, corrections with kicker-magnets are used. The details of the study will be reported in this paper.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW033  
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THPOW034 TLS Booster Injection Scheme Exploration booster, septum, injection, electron 4016
 
  • H.H. Chen, H.-P. Chang, H.C. Chen, S.J. Huang, C.H. Kuo, A.P. Lee, J.A. Li, K.-K. Lin, Y.K. Lin
    NSRRC, Hsinchu, Taiwan
  
  In this paper, the booster injection efficiency and the parameter working range related to key components in-cluding septum magnet and kicker magnet for Taiwan Light Source (TLS) injector operation are introduced. Booster injection scheme for different lattice is explored by machine study plan using injector property. The study result may be used by the operator as booster injection parameter fine tuning reference. It is also helpful for the advanced injection scheme exploration.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW034  
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