Keyword: resonance
Paper Title Other Keywords Page
MOZA02 Design and Optimization Strategies of Nonlinear Dynamics in Diffraction-limited Synchrotron Light Sources sextupole, lattice, optics, emittance 33
 
  • R. Bartolini
    DLS, Oxfordshire, United Kingdom
  • R. Bartolini
    JAI, Oxford, United Kingdom
  
  This talk introduces the most recent achievements in the control of nonlinear dynamics in electron synchrotron light sources, with special attention to diffraction limited storage rings. Guidelines for the design and optimization of the magnetic lattice are reviewed and discussed.  
slides icon Slides MOZA02 [4.952 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOZA02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMB058 Bunch Arrival Time Monitor Test at PAL-XFEL ITF pick-up, LLRF, cavity, simulation 223
 
  • J.H. Hong, J.H. Han, C. Kim, H. Yang
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Femtosecond resolution electron bunch arrival time monitor (BAM) will be required for the beam-based RF phase feedback during PAL-XFEL operation. Two S-band cavity-type BAMs were manufactured for the test at the PAL-XFEL injector test facility (ITF). The resonance frequencies of the cavities are 2856 MHz and 2826.25 MHz. Electron beam induced signal from the cavities was digitized using a low level RF (LLRF) module. In this paper, the resolution of these cavities are analyzed and a possible improvement for better resolution are discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB058  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMW026 Resonant Control for Fermilab's PXIE RFQ rfq, controls, operation, cavity 447
 
  • D.L. Bowring, B.E. Chase, J. Czajkowski, J.P. Edelen, D.J. Nicklaus, J. Steimel, T.J. Zuchnik
    Fermilab, Batavia, Illinois, USA
  • S. Biedron, A.L. Edelen, S.V. Milton
    CSU, Fort Collins, Colorado, USA
  
  Funding: Work supported by Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359.
The RFQ for Fermilab's PXIE test program is designed to accelerate a < 10 mA H− CW beam to 2.1 MeV. The RFQ has a four-vane design, with four modules brazed together for a total of 4.45 m in length. The RF power required is < 130 kW at 162.5 MHz. A 3 kHz limit on the maximum allowable frequency error is imposed by the RF amplifiers. This frequency constraint must be managed entirely through differential cooling of the RFQ's vanes and outer body and associated material expansion. Simulations indicate that the body and vane coolant temperature should be controlled to within 0.1 degrees C. We present the design of the cooling network and the resonant control algorithm for this structure, as well as results from initial operation. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW026  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOR004 Recent Progress of 1-MW Beam Tuning in the J-PARC 3-GeV RCS injection, emittance, scattering, power-supply 592
 
  • H. Hotchi, H. Harada, S. Kato, M. Kinsho, K. Okabe, P.K. Saha, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, K. Yamamoto, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  The J-PARC 3-GeV RCS started 1 MW beam test from October 2014, and successfully achieved a 1 MW beam acceleration in January 2015. Since then, a large fraction of our effort has been focused on reducing and managing beam losses. This paper presents the recent progress of 1 MW beam tuning, especially focusing on our approaches to beam loss issues, such as space-charge induced beam loss and foil scattering beam loss during charge-exchange injection, etc.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR004  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOR019 Beta Function Measurement and Resonances Induced by Space Charge Force and Lattice Magnets space-charge, lattice, emittance, simulation 641
 
  • K. Ohmi, K.G. Sonnad
    KEK, Ibaraki, Japan
  
  J-PARC MR has been operated at tune (νx,νy)=(22.40,20.75). A new operating point around (21.4,21.4) has been proposed by simulation studies on space charge effect since 2013. Machine experiments at the operating point has been performed since 2014 and many encouraging results are being obtained. We discuss why new operating point is better than present one from view point of space charge effects.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOR021 Space Charge Studies with High Intensity Single Bunch Beams in the CERN SPS emittance, injection, brightness, space-charge 644
 
  • H. Bartosik, F. Schmidt
    CERN, Geneva, Switzerland
  • A. Oeftiger
    EPFL, Lausanne, Switzerland
  • M. Titze
    HZB, Berlin, Germany
  
  In order to reach the target beam parameters of the LHC injectors upgrade (LIU) project the beam degradation due to losses and emittance growth on the long injection plateau of the SPS needs to be minimized. A detailed study of the dependence of losses, transverse emittance blow-up and transverse beam tail creation as function of the working point is presented here for a high brightness single bunch beam with a vertical space charge tune spread of about 0.2 on the 26 GeV injection plateau. The beam behaviour close to important betatron resonances is characterised and a region in the tune diagram with minimal beam degradation is identified. Implications about the performance for LIU beams are discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOR023 Flat Bunches with a Hollow Distribution for Space Charge Mitigation space-charge, synchrotron, emittance, injection 652
 
  • A. Oeftiger, H. Bartosik, A. Findlay, S. Hancock, G. Rumolo
    CERN, Geneva, Switzerland
  • A. Oeftiger
    EPFL, Lausanne, Switzerland
  
  Funding: CERN, Doctoral Studentship EPFL, Doctorate
Longitudinally hollow bunches provide one means to mitigate the impact of transverse space charge. The hollow distributions are created via dipolar parametric excitation during acceleration in CERN's Proton Synchrotron Booster. We present simulation work and beam measurements. Particular emphasis is given to the alleviation of space charge effects on the long injection plateau of the downstream Proton Synchrotron machine, which is the main goal of this study. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR023  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOR046 Studies on Depolarization by Synchrotron Radiation using Elegant Particle Tracking synchrotron, radiation, synchrotron-radiation, polarization 695
 
  • J.F. Schmidt, W. Hillert
    ELSA, Bonn, Germany
  
  Funding: BMBF
Spin dynamics in circular electron accelerators are significantly influenced by the emission of synchrotron light. In storage rings, Sokolov-Ternov polarization build-up and radiative depolarization have crucial impact on equilibrium polarization. On shorter timescales, as in damping rings or synchrotrons with fast energy ramp, the temporal development of polarization depends on spin decoherence caused by stochastic momentum changes. Thus, especially longitudinal beam dynamics affect depolarization. This contribution presents the implementation of particle tracking with synchrotron radiation from Elegant in an in-house developed spin tracking code. Exemplary results on depolarization including synchrotron radiation are shown. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR046  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOW008 Reverse Undulator Tapering for Polarization Control at XFELs undulator, FEL, radiation, bunching 722
 
  • E. Schneidmiller, M.V. Yurkov
    DESY, Hamburg, Germany
  
  Baseline design of a typical X-ray FEL undulator assumes a planar configuration which results in a linear polarization of the FEL radiation. However, many experiments at X-ray FEL user facilities would profit from using a circularly polarized radiation. As a cheap upgrade one can consider an installation of a short helical afterburner, but then one should have an efficient method to suppress powerful linearly polarized background from the main undulator. We describe a method for such a suppression: an application of the reverse taper in the main undulator*. In a certain range of the taper strength, the density modulation (bunching) at saturation is practically the same as in the case of non-tapered undulator while the power of linearly polarized radiation is suppressed by orders of magnitude. Then strongly modulated electron beam radiates at full power in the afterburner. The scheme was successfully tested at LCLS** and is routinely used in user experiments. In this contribution we present the theoretical description of the method as well as the results of experiments with reverse taper at FLASH2.
* E.A. Schneidmiller and M.V. Yurkov, Phys. Rev. ST-AB 16, 110702 (2013)
** H.-D. Nuhn et al., "Commissioning of the DELTA polarizing undulator at LCLS", Proc. of FEL2015 Conf., Daejeon, Korea 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW008  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOY003 Study of Achieving Low Energy Beam by Energy Degradation and Direct Resonance Extraction in a Compact Ring extraction, space-charge, synchrotron, simulation 850
 
  • G.R. Li, X.W. Wang, Z. Yang, H.J. Yao, Q. Zhang, S.X. Zheng
    TUB, Beijing, People's Republic of China
  • X. Guan
    Tsinghua University, Beijing, People's Republic of China
  
  We have designed a compact proton synchrotron(7~230 MeV) for applications like proton therapy and space environment study. These applications may require slow extraction from 10~230 MeV. Traditionally, the low energy beam(10~70 MeV) is achieved by energy degradation from high energy beam which may cause beam lose and energy spread increase, because the beam quality may suffer from magnetic remanence, power ripple and strong space charge effects in low energy stage. To achieve high quality beam directly from resonance extraction, we study these effects by performing multi-particle simulation. Methods of improving beam quality are discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY003  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOY010 Simulations and Measurements of Stopbands in the Fermilab Recycler simulation, space-charge, proton, operation 864
 
  • R. Ainsworth, P. Adamson, K.J. Hazelwood, I. Kourbanis, E.G. Stern
    Fermilab, Batavia, Illinois, USA
  
  Fermilab has recently completed an upgrade to the complex with the goal of delivering 700 kW of beam power as 120 GeV protons to the NuMI target. A major part of boosting beam power is to use the Fermilab Recycler to stack protons. Simulations focusing on the betatron resonance stopbands are presented taking into account different effects such as intensity and chromaticity. Simulations are compared with measurements.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY010  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOY019 Status of the First CH-Cavities for the New Superconducting CW Heavy Ion LINAC@GSI cavity, linac, operation, ion 886
 
  • M. Basten, M. Amberg, M. Busch, F.D. Dziuba, H. Podlech, M. Schwarz
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • K. Aulenbacher, W.A. Barth, V. Gettmann, S. Mickat, M. Miski-Oglu
    HIM, Mainz, Germany
  • W.A. Barth, M. Heilmann, S. Mickat, S. Yaramyshev
    GSI, Darmstadt, Germany
  
  In the field of Super Heavy Elements (SHE) a superconducting (sc) continuous wave (cw) high intensity heavy ion LINAC is highly desirable. Currently a multi-stage R&D program conducted by GSI, HIM and IAP* is in progress. The baseline linac design composes a high performance ion source, a new low energy beam transport line, a (cw) upgraded High Charge State Injector (HLI), and a matching line (1.4 MeV/u) followed by the new sc-DTL LINAC for acceleration up to 7.3 MeV/u. The commissioning of the first CH cavity (Demonstrator), in a horizontal cryo module with beam is a major milestone in 2016**. The advanced demonstrator comprises constant-beta sc Crossbar-H-mode (CH) cavities operated at 217 MHz. Presently, the first two sc CH cavities of the advanced demonstrator are under construction at Research Instruments (RI), Bergisch Gladbach, Germany. A string of cavities and focusing elements build from several short CH-cavities with 8 gaps, without girders is recommended. The new design potentially reduces the overall technical risks during the fabrication and the pressure sensitivity through stiffening brackets. The present status of the first two sc cavities will be presented.
* W.Barth et al., Further R&D for a new Superconducting cw Heavy Ion LINAC@GSI, IPAC'14
**F.Dziuba et al., Measurements on the Superconducting 217 MHz CH Cavity during the Manufacturing Phase, SRF2015 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPOY020 Prototype Design of a Newly Revised CW RFQ for the High Charge State Injector at GSI rfq, simulation, operation, impedance 889
 
  • D. Koser, H. Podlech
    IAP, Frankfurt am Main, Germany
  • P. Gerhard, L. Groening, O.K. Kester
    GSI, Darmstadt, Germany
  
  Within the scope of the FAIR project (Facility for Antiproton and Ion Research) at GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany, the front end of the existing High Charge State Injector (HLI) is planned to be upgraded for cw operation. The required newly revised 4-Rod RFQ structure is currently being designed at the Institute for Applied Physics (IAP) of the Goethe University of Frankfurt. It will be operated with a 100 kW power amplifier at 108 MHz. At first instance a dedicated 4-stem prototype, which is based on the RFQ design for MYRRHA* and FRANZ**, is planned to be manufactured in order to validate the simulated RF performance, thermal behavior and mechanical characteristics in continuous operation. The RF simulations as well as basic thermal simulations are done using CST Studio Suite. In order to prevent oscillations of the electrodes mechanical eigenmodes are analyzed using ANSYS Multiphysics. In addition the ANSYS software allows more sophisticated simulations regarding the cooling capability by considering fluid dynamics in water cooling channels, thus providing a more detailed thermal analysis.
*C. Zhang, H. Podlech, New Reference Design of the European ADS RFQ Accelerator For MYRRHA, IPAC2014
**M. Heilmann et al., A Coupled RFQ-IH Cavity for the Neutron Source FRANZ, IPAC2013
 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY020  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMB016 Continuous-Wave Electron Linear Accelerators for Industrial Applications linac, electron, klystron, accelerating-gradient 1142
 
  • D.S. Yurov, A.S. Alimov, B.S. Ishkanov, V.I. Shvedunov
    MSU, Moscow, Russia
  
  Based on SINP MSU experience in developing continuous wave (CW) normal conducting (NC) electron linacs, we propose an optimal design for such accelerators with beam energy of up to 10 MeV and average beam power of up to several hundred kW. As an example of such design, we discuss the 1 MeV industrial CW linac with maximum beam power of 25 kW, which was recently commissioned at SINP MSU.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB016  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMR011 Development of Optimized RF Cavity in 10 MeV Cyclotron network, cyclotron, cavity, simulation 1250
 
  • M. Mohamadian, H. Afarideh, M. Salehi
    AUT, Tehran, Iran
  • J.-S. Chai, M. Ghergherehchi
    SKKU, Suwon, Republic of Korea
  
  Cyclotron cavity modelled by an artificial neural net-work, which is trained by our optimized algorithm. The training samples are obtained from simulation results, which are done by MWS CST software for some defined situation and parameters, and also with the conventional BP algorithm. It is shown that the optimized FFN can estimate the cyclotron model parameters with acceptable outputs. Hence, the neural network trained by this algorithm represents the proper estimation and acceptable ability to our structure modelling. The cyclotron cavity parameter modelling illustrate that the neural network trained by this algorithm could be the acceptable method to design parameters.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR011  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMR018 Beam Tracking Simulation for SC200 Superconducting Cyclotron cyclotron, simulation, extraction, acceleration 1268
 
  • O. Karamyshev
    JINR/DLNP, Dubna, Moscow region, Russia
  • Y.F. Bi, G. Chen, K.Z. Ding, Y. Song
    ASIPP, Hefei, People's Republic of China
  • G.A. Karamysheva, N.A. Morozov, E.V. Samsonov, G. Shirkov, S.G. Shirkov
    JINR, Dubna, Moscow Region, Russia
  
  The SC200 superconducting cyclotron for hadron therapy is under development by collaboration of ASIPP (Hefei, China) and JINR (Dubna, Russia). The accelerator will provide 200 MeV proton beam with maximum current of 1μA in 2017-2018. The cyclotron is very compact and light, the estimate total weight is about 30 tons and extraction radius is 60 cm. We have performed simulations of all systems of the SC200 cyclotron and specified the main parameters of the accelerator. Average magnetic field of the cyclotron is up to 3.5 T and the particle revolution frequency is about 45 MHz, these parameters increases the requirements for accuracy of the beam dynamics studies. We have designed and performed beam tracking starting from the ion source. Codes and methods used for the beam tracking are presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR018  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMR036 Extraction Commissioning for MedAustron Proton Operation extraction, synchrotron, simulation, sextupole 1327
 
  • T.K.D. Kulenkampff, A. Garonna, M. Kronberger, C. Kurfürst, S. Nowak, F. Osmić, L.C. Penescu, M.T.F. Pivi, C. Schmitzer, P. Urschütz, A. Wastl
    EBG MedAustron, Wr. Neustadt, Austria
  
  MedAustron is a synchrotron based ion beam therapy center for proton (62-250 MeV) and carbon ion (120-400 MeV/n) treatments. The MedAustron synchrotron uses a betatron core driven slow extraction scheme based on a third order resonance. The commissioning of the extraction from the synchrotron involved the setup of the correct orbit and optics at flattop. In order to maximize the momentum spread before extraction and optimize spill structure the RF system enforces a so called RF-phase jump to the unstable phase. Different scenarios were simulated using MADX-PTC [1] in combination with Python to overcome the static nature of PTC. Simulations have shown that the initial phase of the beam and a finite time to jump to the unstable fix point have a strong impact on the performance. Using a high frequency intensity monitor in the extraction channel (QIM), the spill structure was analysed and used for optimization. Simulation and measurements of the procedure are presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR036  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMR037 Betatron Core Driven Slow Extraction at CNAO and MedAustron extraction, betatron, synchrotron, proton 1330
 
  • M. G. Pullia, E. Bressi, L. Falbo, C. Priano, S. Rossi, C. Viviani
    CNAO Foundation, Milan, Italy
  • A. Garonna, M. Kronberger, T.K.D. Kulenkampff, C. Kurfürst, F. Osmić, L.C. Penescu, M.T.F. Pivi, C. Schmitzer, P. Urschütz, A. Wastl
    EBG MedAustron, Wr. Neustadt, Austria
  
  The Italian Centre for Hadrontherapy (CNAO) and the MedAustron Hadrontherapy Center in Austria are synchrotron-based medical therapy centers. The CNAO machine has five years of experience in patient treatments, whereas MedAustron will soon start patient treatments with protons. Their accelerator systems have common characteristics, in particular in regards to the extraction system: at acceleration flattop, particles are slowly driven through the third integer resonance longitudinally by a betatron core. This setup enables smooth extracted beam intensities. The rationale behind the use of a betatron core, its impact on the extracted beam quality and the performance from operation and commissioning of the two centers will be here presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR037  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMR060 Improvement of 18 MeV Cyclotron Magnet Design by TOSCA Code cyclotron, simulation, betatron, factory 1397
 
  • N. Rahimpour Kalkhoran, H. Afarideh, R. Solhju
    AUT, Tehran, Iran
  • J.-S. Chai, M. Ghergherehchi
    SKKU, Suwon, Republic of Korea
  
  According to increasing need to cyclotrons in the world, designing and manufacturing of these machines are considered. Therefore designing of 18 MeV cyclotron magnet has begun at Amirkabir University Of Technology. Magnet is one of the most important parts of the cyclotron, so in designing of magnet, all other components of cyclotron which influence on magnet, should be considered. Since the achievable energy for particle is determined 18MeV, designed magnet has AVF structure. TOSCA (Opera-3D) code was selected for simulation and analysis. First of all, theoretical calculations and estimations were done and magnetic field data according to radius were achieved, after that, simulation with initial estimations and a simple model of magnet was begun and optimization process continued until magnetic field results from the simulation coincided with the theoretical one. Different shimmings were used for better coincidence. Some results contains magnetic field on middle plane and betatron oscillations were checked. Also working points of the cyclotron with resonance regions were checked. According to use reliable mesh, the accuracy of simulation results is sufficient high.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR060  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMW036 Optimizing Chromatic Coupling Measurement in the LHC coupling, dipole, sextupole, quadrupole 1520
 
  • T. Persson, R. Tomás
    CERN, Geneva, Switzerland
  
  Optimizing chromatic coupling measurement in the LHC Chromatic coupling introduces a dependency of transverse coupling with energy. LHC is equipped with skew sextupoles to compensate the possible adverse effects of chromatic coupling. In 2012 a beam-based correction was calculated and applied successfully for the fist time. However, the method used to reconstruct the chromatic coupling was dependent on stable tunes and equal chromaticities between the horizontal and vertical planes. In this article an improved method to calculate the chromatic coupling without these constraints is presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW036  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOR023 Investigation of Trapped Resonant Modes in Insertion Devices at the Australian Synchrotron feedback, vacuum, undulator, synchrotron 1710
 
  • R.T. Dowd, M.P. Atkinson, M.J. Boland, G. LeBlanc, Y.E. Tan
    SLSA, Clayton, Australia
  • D. Teytelman
    Dimtel, San Jose, USA
  
  The Australian Synchrotron light Source has 3 variable gap in-vacuum undulators (IVU) in the storage ring. Since installation, these devices have been the source of strong beam instabilities. These instabilities seem to behave as trapped resonant modes of very high Q and high frequency, although a definite source has not been identified. The presence of these instabilities has necessitated operating at unusually high chromaticity for much of the light source's operations. More recently transverse feedback has been able to control the instabilities and recent developments in diagnostics have allowed some investigation of the frequency and mode response of these resonances. The results of this investigation will be presented in this paper.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR023  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOY021 Characterisation of the Spectra of Spallation Neutron Sources through Modelling neutron, proton, target, simulation 1950
 
  • R.J. Barlow, A. Rummana
    IIAA, Huddersfield, United Kingdom
  • R. Seviour
    University of Huddersfield, Huddersfield, United Kingdom
  
  We characterise the neutron flux and energy spectra produced by protons on a lead target. This may enable studies of the neutronics of an ADSR, to be separated from the higher energy spallation processes, in order to explore te potential of ADSR as a better alternative for energy production, safety and waste transmutation. We consider a range of proton energies, and show how the numbers of neutrons produced can be fitted by some simple functions of the proton energy, as can the spatial and energy distributions. These calculations were performed in both MCNPX and Geant4 and we compare and benchmark the low energy neutron spectra obtained by MCNPX code and a Monte Carlo Code Geant4 against each other. Discrepancies were found for the low energy neutron spectrum, but by using different models as calculation options for low energy neutrons in Geant4, this disagreement has been significantly reduced.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOY036 Diffusion and Thermal Stability of Implanted Hydrogen in ZnO Nanorods proton, lattice, ion, radiation 1982
 
  • J.K. Park, Y.-S. Cho, H.-J. Kwon, K.T. Seol, S.P. Yun
    Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
  
  Funding: This work has been supported through KOMAC operation fund of KAERI by Ministry of Science ICT and Future Planning of Korean Government.
The 20-MeV proton-beams with a fluence of 1012 cm-2 were irradiated on ZnO nanorods. The effects of proton-beam irradiation on ZnO nanorods are investigated by using 1H nuclear magnetic resonance (NMR) spectroscopy. After irradiation, new and modified NMR resonance lines are observed in 1H NMR spectra. The diffusion and thermal stability of each proton species are investigated from the lab- and rotating-frame spin-lattice relaxation data depending on temperature. Understanding the properties of thermally stable hydrogen species created by the beam irradiation may promise many possible applications, since the hydrogen stable up to high temperature only meets the device working conditions. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY036  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPOY046 Study on NRF-CT Imaging by Laser Compton Backscattering Gamma-rays in UVSOR target, detector, laser, photon 2007
 
  • H. Ohgaki, I. Daito, T. Kii, H. Zen
    Kyoto University, Kyoto, Japan
  • T. Hayakawa, T. Shizuma
    JAEA, Ibaraki-ken, Japan
  • M. Katoh, J. Yamazaki
    UVSOR, Okazaki, Japan
  • Y. Taira, H. Toyokawa
    AIST, Tsukuba, Japan
  
  Funding: This work was supported by JSPS KAKENHI Grant Number 26289363, 24340060 and the Joint Studies Program (2014) of the Institute for Molecular Science.
Monochromatic gamma-ray beam in MeV energy region is suitable for non-destructive inspection of high density and massive objects because of its high penetrability. A specific nuclide can be detected by the process of Nuclear Resonance Fluorescence (NRF). A non-destructive inspection of Special Nuclear Materials hidden in a container cargo using NRF is proposed by Bertozzi*. Non-destructive detection of Pu inside of a spent nuclear fuel rod is also proposed for management of radioactive wastes, nuclear material accounting and safeguards**. We have developed 2D NRF imaging by using quasi-monochromatic gamma-ray beam in MeV energy region generated by Laser Compton Backscattering (LCS) method*** and proposed to develop an NRF-CT image in the ELI-NP where a high intensity LCS beam can be available in near future. To demonstrate and finalize the measurement system of the NRF-CT imaging by using LCS gamma-ray beam, we have started a study on NRF-CT imaging at the new LCS beamline in UVSOR. The LCS beamline can generate 5.4 MeV LCS gamma-rays with a flux of 1×107 photons/s. We have measured the 5.291 MeV NRF gamma-rays from a lead target in this beamline and tried to take a NRF-CT image.
* W. Bertozzi et al., Nucl. Inst. Meth. B241, 820-825 (2005).
** B. Ludewigt et al., Proc. of 2010 ANS meeting (2010).
*** H. Toyokawa et al., JJAP, 50, 100209 (2011). 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOY046  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEOAA01 Transverse Emittance Exchange for Improved Injection Efficiency emittance, coupling, synchrotron, injection 2028
 
  • P. Kuske, F. Kramer
    HZB, Berlin, Germany
  
  In most cases beam is injected into electron storage rings in the horizontal plane and off-axis. The larger the horizontal emittance of the injected beam the larger the acceptance of the ring has to be. The injected beam is usually delivered by a synchrotron. In case the vertical acceptance of the ring is sufficiently large one can take advantage of the small vertical emittance reached in well aligned and tuned synchrotrons since the transverse emit-tances can be exchanged with the help of skew quadru-pole magnets. A few possible processes will be discussed: emittance exchange with static magnets in the transfer line between synchrotron and ring or emittance exchange in the synchrotron shortly before extraction with time dependent magnets. This could be a suddenly switched-on normal or skew quadrupole magnet or skew quadru-pole fields oscillating at a frequency fulfilling the reso-nance condition. Estimates for these magnets and their design will be given.  
slides icon Slides WEOAA01 [0.852 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPMB050 RF Test of ESS Superconducting Spoke Cavities at Uppsala University cavity, pick-up, radiation, controls 2227
 
  • H. Li, A.K. Bhattacharyya, V.A. Goryashko, L. Hermansson, R.J.M.Y. Ruber, R. Santiago Kern
    Uppsala University, Uppsala, Sweden
  • N. Gandolfo, G. Olry
    IPN, Orsay, France
  
  The European Spallation Source (ESS) is an accelerator-driven neutron spallation source built in Sweden. It will deliver the first protons to a rotating tungsten target by 2019 and will reach the full 5 MW average beam power in the following years. The superconducting Spoke cavities are considered compact structures at low frequencies and having an excellent RF performance in both low and medium velocity regimes, therefore ESS will include a total of 26 double-spoke cavities. The testing of the double-spoke prototype cavity at high power has been conceded to Uppsala University, Sweden, where the Facility for Research Instrumentation and Accelerator development (FREIA) has been equipped with superconducting cavity test facility. A bare spoke cavity has been tested at the FREIA Laboratory with a self-exited loop at low power level to confirm its vertical test performance at IPNO. Similar test results as IPNO's previous test were obtained with FREIA system. In this paper we present the methods and preliminary study results of the cavity performance.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB050  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPMR013 Study of LCLS-II Fundamental Power Coupler Heating in HTS Integrated Cavity Tests cavity, HOM, vacuum, simulation 2286
 
  • N. Solyak, I.V. Gonin, A. Grassellino, C.J. Grimm, T.N. Khabiboulline, J.P. Ozelis, K. Premo, O.V. Prokofiev, D.A. Sergatskov, G. Wu
    Fermilab, Batavia, Illinois, USA
  
  LCLS-II coupler based on modified design of TTF3 coupler for higher average power was assembled on high Q cavity and tested at HTS as part of integrated cavity test program. Couplers were thermally connected to thermal shields and equipped with diagnostics to control temperature in different locations and provide information about cryogenic heat loads at 2 K, 5 K and 80 K.Three dressed cavities with power couplers were tested in HTS at full specified RF power. Results are summarized in this paper and cross-checked with simulation.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR013  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPMW017 Ion Beam Polarization Dynamics in the 8 Gev Booster of the Jleic Project at Jlab booster, proton, polarization, quadrupole 2460
 
  • V.S. Morozov, Y.S. Derbenev, F. Lin, Y. Zhang
    JLab, Newport News, Virginia, USA
  • Y. Filatov
    MIPT, Dolgoprudniy, Moscow Region, Russia
  • A.M. Kondratenko, M.A. Kondratenko
    Science and Technique Laboratory Zaryad, Novosibirsk, Russia
  
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
In the Jefferson Lab's Electron-Ion Collider (JLEIC) project, an injector of polarized ions into the collider ring is a superconducting 8 GeV booster. Both figure-8 and racetrack booster versions were considered. Our analysis showed that the figure-8 ring configuration allows one to preserve the polarization of any ion species during beam acceleration using only small longitudinal field with an integral less than 0.5 Tm. In the racetrack booster, to preserve the polarization of ions with the exception of deuterons, it suffices to use a solenoidal Siberian snake with a maximum field integral of 30 Tm. To preserve deuteron polarization, we propose to use arc magnets for the race-track booster structure with a field ramp rate of the order of 1 T/s. We calculate deuteron and proton beam polarizations in both the figure-8 and racetrack boosters including alignment errors of their magnetic elements using the Zgoubi code. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW017  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOR032 Power Recycling of Burst-mode Laser Pulses for Laser Particle Interactions cavity, laser, experiment, ion 2739
 
  • Y. Liu, A. Rakhman
    ORNL, Oak Ridge, Tennessee, USA
  • A. Rakhman
    UTK, Knoxville, Tennessee, USA
  
  Funding: This work has been partially supported by U.S. DOE grant DE-FG02-13ER41967. ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
A number of laser-particle interaction experiments such as the laser assisted hydrogen ion beam stripping or X-/γ-ray generations via inverse-Compton scattering involve light sources operating in a burst mode to match the temporal structure of the particle beam. As the small cross-section in the laser-particle interaction process results in negligible laser power loss, it is desirable to make the interaction inside an optical cavity to recycle the laser power. In many cases, conventional cavity locking techniques will not work since the burst normally has very small duty factor and low repetition rate and it is impossible to generate an effective control signal. In this talk, we report on the development of a doubly-resonant optical cavity scheme and its locking technique that enables a simultaneous resonance of two laser beams with different spectra and/or temporal structures. We demonstrate that such a cavity can be used to recycle burst-mode ultra-violet laser pulses with arbitrary burst lengths and repetition rates. System implementation, technical challenges, experimental results and applications will be described.
* V. Danilov et al., Phys. Rev. ST Accel. Beams 10, 053501 (2007).
** K. Sakaue et al., Rev. Sci. Instrum. 80, 123304 (2009).
*** A. Rakhman, M. Notcutt, and Y. Liu, Opt. Lett. 40, 5562 (2015).
 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR032  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOW013 Coherent Harmonic Generation in the Presence of Synchronized RF Phase Modulation at DELTA electron, synchrotron, laser, radiation 2847
 
  • M.A. Jebramcik, F.H. Bahnsen, M. Bolsinger, S. Hilbrich, M. Höner, S. Khan, C. Mai, A. Meyer auf der Heide, R. Molo, G. Shayeganrad, P. Ungelenk
    DELTA, Dortmund, Germany
  
  Funding: Work supported by the BMBF (05K13PEC), DFG (INST 212/236-1) and the Stiftung Mercator (Pr-2014-0047).
At the 1.5-GeV synchrotron light source DELTA operated by the TU Dortmund University, ultrashort coherent pulses in the VUV and THz regime are generated via coherent harmonic generation (CHG). The intensity of the light depends strongly on the quality of the laser-electron interaction and therefore on the energy spread and density of the electron bunches. In 2014, a significant increase of the CHG intensity was observed by phase-modulating the RF cavity voltage, which is routinely used to prolong the beam lifetime. RF phase modulation can generate multiple stable regimes (islands) in longitudinal phase space when run near an integer multiple of the synchrotron frequency resulting in a modulation of the electron density and energy spread. A numerical simulation supporting the experimental observations is presented. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW013  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOW035 Commissioning of the Harmonic Cavities in the MAX IV 3 GeV Ring cavity, damping, storage-ring, synchrotron 2911
 
  • G. Skripka, Å. Andersson, A.M. Mitrovic, P.F. Tavares
    MAX IV Laboratory, Lund University, Lund, Sweden
  • F.J. Cullinan, R. Nagaoka
    SOLEIL, Gif-sur-Yvette, France
  
  The MAX IV 3 GeV storage ring operates with beam of high current and ultralow emittance. These beam parameters in combination with the small effective aperture enhance possible collective beam instabilities. Three passive harmonic cavities are installed to introduce bunch lengthening and tune spread, leading to decoupling of the bunch spectrum from the machine effective impedance and mitigating instabilities by Landau damping respectively. In this paper we present the first results of the commissioning of the passive third harmonic cavities in the MAX IV 3 GeV ring. The additional harmonic cavity potential significantly improved the beam lifetime. First observations of the harmonic cavity effect on the damping of collective beam instabilities are discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW035  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPOW052 Multimodal Interaction in the ALS Longitudinal Feedback Kicker RF Cavity cavity, kicker, feedback, 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  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THOBA02 Space Charge Induced Collective Modes and Beam Halo in Periodic Channels space-charge, focusing, emittance, simulation 3165
 
  • C. Li, Zh.C. Liu, Q. Qin, Y.L. Zhao
    IHEP, Beijing, People's Republic of China
  
  Funding: This work is supported by the Ministry of Science and Technology of China under Grant No. 2014CB845501.
The collective mode instabilities of periodically focused high intensity beams based on the Vlasov-Poisson equation are investigated both analytically and numerically. It is found that the broadened collective stop bands resulting from space charge induced structure resonance in long periodic channels predict well the areas where the rms emittance growth accompanied with n-fold phase space structure (beam halo) would take place. We believe that the formed beam halo, which is depicted in action-angle frame, could be understood as a side-effect of the collective beam mode. 		 
slides icon Slides THOBA02 [4.704 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THOBA02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMB053 nuSTORM FFAG Decay Ring lattice, factory, storage-ring, closed-orbit 3369
 
  • J.-B. Lagrange, J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • R.B. Appleby, J.M. Garland, H.L. Owen, S.C. Tygier
    UMAN, Manchester, United Kingdom
  • R.B. Appleby
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A.D. Bross, A. Liu
    Fermilab, Batavia, Illinois, USA
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  
  The neutrino beam produced from muons decaying in a storage ring would be an ideal tool for precise neutrino cross section measurements and search for sterile neutrinos due to its precisely known flavour content and spectrum. In the proposed nuSTORM facility pions would be directly injected into a racetrack storage ring, where circulating muon beam would be captured. The storage ring has two options: a FODO solution with large aperture quadrupoles and a racetrack FFAG (Fixed Field Alternating Gradient) using the recent developments in FFAGs. Machine parameters, linear optics design and beam dynamics are discussed in this paper.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB053  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR001 Online Suppression of the Sextupole Resonance Driving Terms in the Diamond Storage Ring sextupole, storage-ring, optics, injection 3381
 
  • I.P.S. Martin, M. Apollonio, R. Bartolini
    DLS, Oxfordshire, United Kingdom
  • R. Bartolini
    JAI, Oxford, United Kingdom
  
  Suppression of the sextupole resonance driving terms (RDTs) is a widely used technique for optimising the theoretical on and off-momentum dynamic aperture for electron storage rings. Recently, this technique was applied online to the Diamond storage ring, with suppression of individual RDTs achieved via a sextupole family to RDT response matrix*. In this paper we present recent studies of the method, in which the ability to improve the lifetime and injection efficiency are investigated. An extension of the technique is investigated by combining it with the Robust Conjugate Direction Search (RCDS) optimisation algorithm**.
*J. Bengtsson, et al., Phys. Rev. ST Accel. Beams 18, 074002, (2015).
**X. Huang, et al., Nucl. Instrum. Methods Phys. Res. Sect. A 726, 77, (2013).
 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR001  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR014 Core-halo Limits and Beam Halo-formation Dynamic space-charge, emittance, focusing, plasma 3417
 
  • M. Valette, P.A.P. Nghiem
    CEA/IRFU, Gif-sur-Yvette, France
  • N. Pichoff
    CEA/DSM/IRFU, France
  
  In high intensity linear accelerators, space charge related instabilities and effects are the cause of emittance increase and beam losses. The mechanism of halo formation due to a mismatched beam causing parametric resonances and energy transfer between phase-spaces is one of them. The previously defined one dimensional core-halo limit [1][2] was extended to two dimensional distributions [3][4]. This halo characterization method is applied to a classical case of transport for halo formation studies: the transport of a mismatched beam. Our method provides a core-halo limit that matches the expected halo formation mechanism with a very good precision.
* Appl. Phys. Lett. 104, 074109 (2014)
** Phys. Plasmas, 22, 083115, (2015)
*** IPAC (2015) MOPWA010
**** TBP 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR014  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR015 RCDS Optimizations for the ESRF Storage Ring sextupole, injection, optics, emittance 3420
 
  • S.M. Liuzzo, N. Carmignani, L. Farvacque, B. Nash, T.P. Perron, P. Raimondi, R. Versteegen, S.M. White
    ESRF, Grenoble, France
  
  The Robust Conjugate Direction Search (RCDS)* optimizer is applied for online optimizations of the ESRF accelerators. This paper presents the successful application of the algorithm in reducing vertical emittance, improving injection efficiency and increasing lifetime. A new set of sextupole settings to increase chromaticity has been obtained with lifetimes comparable to the existing one. This allows to run with double current in a single bunch, and unifies the optics for few bunch (except 4x10 bunches) and multi-bunch modes.
* X. Huang, J. Corbett, J. Safranek, J. Wu, "An algorithm for online optimization of accelerators", Nucl. Instr. Methods, A 726 (2013) 77-83. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR015  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR017 Resonance Island Experiments at BESSY II for User Applications undulator, photon, operation, experiment 3427
 
  • P. Goslawski, J. Feikes, K. Holldack, A. Jankowiak, M. Ries, M. Ruprecht, A. Schälicke, G. Wüstefeld
    HZB, Berlin, Germany
  • R. Ovsyannikov
    BESSY GmbH, Berlin, Germany
  
  Beam storage close to a tune resonance (Qx = 1/3, 1/4) can generate resonance island buckets in the x,x' phase space providing a second stable island orbit winding around the standard orbit. Experiments with such an operation mode have been conducted at BESSY II and the Metrology Light Source (MLS)*,**. The two orbits are well separated, with good life time and stability. Such operation mode will offer additional operation flexibility and allows users to choose their radiation source point from one or the other orbit. It has the potential to fulfill simultaneously conflicting user demands, e.g., high vs. low beam current and single or few bunch filling vs. multibunch filling. We discuss the required beam optics setup and present successful measurements taken at photon beamlines at BESSY II.
* P. Goslawski et al., "Bunch Separation by Transverse Resonance Island Buckets", ESLS XXIII Workshop, 2015, Villigen, Switzerland.
** M. Ries et al., Proc. IPAC 2015, Richmond, USA, MOPWA021. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR017  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR021 Bmad Model of COSY, Status and Progress lattice, sextupole, proton, polarization 3437
 
  • Y. Dutheil
    FZJ, Jülich, Germany
  
  Abstract The COSY in Jülich is a versatile machine with a long history of polarized proton acceleration. A new model of COSY based on the Bmad library was developed to simulate beam and spin dynamics. Original methods of lattice design, notably multi-objective lattice optimization, were explored. This contribution presents the status and development steps of the Bmad model of COSY. Some of the latest simulations will also be discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR025 Simulation of Beam Behavior Caused by Odd Harmonics of Beam Loading in J-PARC RCS beam-loading, simulation, cavity, acceleration 3443
 
  • M. Yamamoto, M. Nomura, T. Shimada, F. Tamura
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • K. Hara, K. Hasegawa, C. Ohmori, M. Toda, M. Yoshii
    KEK, Tokai, Ibaraki, Japan
  
  The J-PARC RCS accelerates 2 bunches at the harmonic number 2. The major Fourier component of the beam current is even harmonics. However, the odd harmonics grow under some conditions even though they are very small amplitude at the beginning. We describe the the particle tracking simulation results for the odd harmonic beam loading effect in the RCS.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR025  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR032 Dynamical Aperture Control in Accelerator Lattices With Multipole Potentials controls, multipole, lattice, octupole 3455
 
  • I.A. Morozov, E.B. Levichev
    BINP SB RAS, Novosibirsk, Russia
  
  We apply two analytical methods to control accelerator dynamic aperture (DA) with multipole potentials. Both methods assume that accelerator model can be represented as a product of unperturbed and perturbed exponential operators with exponent of perturbed operator given as formal power series in perturbation parameter and known dependence of series coefficients on lattice parameters such as multipole strength distribution. Normal form method can be applied to the above representation and then lattice parameters are used to control normal form Hamiltonian coefficients. Hamiltonian control can be used to compute control term and lattice parameters are then fitted to approximate corresponding controlled operator. Theoretical results as well as model examples are presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR032  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR037 Observations of Resonance Driving Terms in the LHC during Runs I and II dipole, injection, betatron, dynamic-aperture 3468
 
  • F.S. Carlier, J.M. Coello de Portugal, E.H. Maclean, T. Persson, R. Tomás
    CERN, Geneva, Switzerland
  
  Future operations of the LHC will require a good understanding of the nonlinear beam dynamics. In 2012, turn-by-turn measurements of large diagonal betatron excitations in LHC Beam 2 were taken at injection energy. Spectral analysis of these measurements shows an anomalous octupolar spectral line at frequency -Qx-2Qy in the horizontal motion. The presence of this spectral line, as well as other lines, was confirmed by measurements taken for LHC Beam 1 and Beam 2 during the commissioning in 2015. We take a close look at the various spectral lines appearing in the LHC transverse motion in order to improve the LHC nonlinear model.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR037  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR043 Performance of Transverse Beam Splitting and Extraction at the CERN Proton Synchrotron in the Framework of Multi-turn Extraction extraction, septum, proton, sextupole 3492
 
  • G. Sterbini, J.C.C.M. Borburgh, S. Damjanovic, S.S. Gilardoni, M. Giovannozzi, C. Hernalsteens, M. Hourican, A. Huschauer, K. Kahle, G. Le Godec, O. Michels
    CERN, Geneva, Switzerland
  • C. Hernalsteens
    EPFL, Lausanne, Switzerland
  
  Considerable progress has been made in 2015 in the setting up of the multi-turn extraction (MTE) in the CERN Proton Synchrotron (PS). A key ingredient in this novel extraction technique is the beam splitting in transverse phase space. This manipulation is based on adiabatic trapping in stable islands of transverse phase space and requires mastering a number of devices in the PS ring. In addition, an in-depth review of all fast extractions schemes in the PS had been required due to the development and installation of a dummy septum to shield the actual magnetic septum. In this paper, the current performance of the beam splitting and of the extraction including the shadowing effect is presented. Future lines of development will also be discussed.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR043  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMR044 Short Term Dynamic Aperture with AC Dipoles dipole, dynamic-aperture, simulation, operation 3496
 
  • S. Mönig, J.M. Coello de Portugal, A. Langner, E.H. Maclean, T. Persson, R. Tomás
    CERN, Geneva, Switzerland
  
  The dynamic aperture of an accelerator is determined by its non-linear components and errors. Control of the dynamic aperture is important for a good understanding and operation of the accelerator. The AC dipole, installed in the LHC for the diagnostic of linear and non-linear optics, could serve as a tool for the determination of the dynamic aperture. However, since the AC dipole itself modifies the non-linear dynamics, the dynamic aperture with and without AC dipole are expected to differ. This paper will report the results of studies of the effect of the AC dipole on the dynamic aperture.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR044  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMW024 Phase Tuning Results of the Waveguide Network System at Pal network, target, klystron, linac 3597
 
  • K.H. Kim, S.H. Kim, H.-S. Lee, S.S. Park, Y.J. Park
    PAL, Pohang, Republic of Korea
  
  We report the results of the phase tuning of the waveguide network system with the C-clamp tool and the resonance frequency tuning for the SLAC energy doubler. The high power waveguide network which dividing and feeding the power to the four accelerating structures. The phase length is adjusted within ± 0.25 degrees with a transmission phase measuring method. The resonant frequency range for the SLAC energy doubler is 2856 MHz ± 5 kHz, but a target range is 2856 MHz ± 1 kHz. We measured the phase length and an amplitude with a vector network analyser. The test setup consists of a SLED, a waveguide network, directional couplers, phase stable cables. All components of the waveguide networks were manufactured at VITZRO TECH and tested at the accelerator tunnel in the Pohang Accelerator Laboratory (PAL).  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW024  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMY009 Coaxial Wire Method Adapted to Weakly Coupled Resonator Mode for LHC RF Fingers Evaluation impedance, coupling, cavity, vacuum 3670
 
  • C. Vollinger, F. Caspers, T. Kaltenbacher
    CERN, Geneva, Switzerland
  
  In high intensity particle accelerators, RF contact fingers are commonly used to carry the beam induced image current. In addition, they reduce beam impedance by shielding the outer bellows required to compensate mechanical displacements between components. In order to assess the resulting beam impedance from a specific bellow/RF finger configuration, RF measurements are routinely carried out. During these measurements, it was observed that cavity modes in the volume between the fingers and the bellow undulation arise. These resonances occur at significantly higher frequencies than the expected frequency range of interest. Due to their broadband nature, the tails of the imaginary part of these resonances reach into the lower frequency range of interest where it contributes to the beam coupling impedance of the device. For proper evaluation of this contribution, a time domain delay technique in TDT (time domain transmissiometry) was used in order to overcome shortcomings that arise if the classical coaxial wire method is applied to these structures. We present the theory of our method and discuss it in view of the data measured on deformable fingers that were studied for the LHC.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY009  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOR012 Dynamic Aperture Study of the CEPC Main Ring with Interaction Region sextupole, dynamic-aperture, interaction-region, optics 3795
 
  • Y. Wang, S. Bai, T.J. Bian, J. Gao, H. Geng, D. Wang, Y. Zhang
    IHEP, Beijing, People's Republic of China
  • F. Su
    Institute of High Energy Physics (IHEP), People's Republic of China
  
  CEPC is a Circular Electron and Positron Collider proposed by China to mainly study the Higgs boson. In order to achieve factory luminosity, a strong focusing system and low-emittance are required. A momentum acceptance as large as 2\% is also required to get a reasonable beam lifetime. This is one of the key issues of the CEPC accelerator physics. In this paper, the optics design of the interaction region and the optimization of dynamic aperture for the whole ring (single ring scheme) will be presented.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR012  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOR015 CEPC Bunch Lengthening and Cavity HOM Analysis HOM, cavity, collider, factory 3805
 
  • H.J. Zheng, J. Gao, Y. Wang
    IHEP, Beijing, People's Republic of China
  
  In this paper we will show the higher order mode (HOM) analysis of the cavity for the Circular Electron-Positron Collider (CEPC) partial double ring (PDR) scheme. In order to study the single bunch longitudinal instability in CEPC, bunch lengthening and energy spread are estimated based on Gao's theory. Different models are used to study the bunch lengthening and energy spread of the ring.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR015  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOR050 New Working Point for CERN Proton Synchrotron multipole, injection, proton, focusing 3905
 
  • F. Sperati, A. Beaumont, S.S. Gilardoni, D. Schoerling, M. Serluca, G. Sterbini
    CERN, Geneva, Switzerland
  
  The LHC High-luminosity project requests high brightness and intensity beams from the CERN Proton Synchrotron (PS). The generation of such beams is limited due to resonance effects at injection. The impact of resonances can be minimized by performing appropriate correction with dedicated magnets and by optimizing the tune working point. Currently the tune working point at injection is naturally set by the quadrupolar component generated by the one hundred combined function normal conducting magnets installed in the PS, and slightly corrected by low energy quadrupole magnets. In this paper, a study is presented exploiting the use of the available five auxiliary individually powered circuits to adjust the quadrupolar and higher-order multipole components for changing the tune integer at injection. Due to the non-linear contribution of each circuit to the magnetic field distribution a finite-element magnetic model was prepared to predict the required currents in the auxiliary coils. The magnetic model was benchmarked with magnetic measurements and then tested in the PS machine during dedicated machine development times.  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR050  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPOY043 Time Scale of Crab Cavity Failures Relevant for High Luminosity LHC cavity, damping, luminosity, simulation 4196
 
  • K.N. Sjobak, R. Bruce, H. Burkhardt, A. Macpherson, A. Santamaría García
    CERN, Geneva, Switzerland
  • R. Kwee-Hinzmann
    Royal Holloway, University of London, Surrey, United Kingdom
  • A. Santamaría García
    EPFL, Lausanne, Switzerland
  
  Funding: Research supported by the High Luminosity LHC project
A good knowledge of the effects of the crab cavities, required for the baseline High Luminosity LHC (HL-LHC), is needed before the results of the first tests of crab cavity prototypes in the SPS, planned for 2018, will be available. In case of crab cavity failures, we have to make sure that time scales are long enough so that the beams can be cleanly dumped before damage by beam loss occurs. We discuss our present knowledge and modeling of crab cavity induced beam losses, combined with mechanical deformation. We discuss lower limits on the time scales required for safe operation, and possible failure mitigation methods. 		 
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY043  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)