SUSPSNE —  Student Poster Session, Neuer Poster Session Area   (15-Jun-14   14:00—18:00)
Paper Title Page
SUSPSNE001
 Beam-beam Effects in Different Luminosity Levelling Scenarios for the LHC  
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  • X. Buffat, D. Banfi, G.R. Coombs
    EPFL, Lausanne, Switzerland
  • W. Herr, T. Pieloni
    CERN, Geneva, Switzerland
  
  Adjusting luminosity and optimizing the luminous region in each interaction point of the LHC according to the experiments needs has become a requirement to maximize the efficiency of the different detectors. Several techniques are envisaged, most importantly by varying β* or a transverse offset at the interaction point. Coherent and incoherent stability in the presence of beam-beam effects will be discussed in realistic luminosity levelling scenarios for the LHC.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO023  
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SUSPSNE002
 Initial Estimate of Fringe Field Effects in HL-LHC using Frequency Map Analysis  
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  • S. Jones, D. Newton, A. Wolski
    The University of Liverpool, Liverpool, United Kingdom
  • S. Jones, D. Newton, A. Wolski
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Funding: Work supported by the Science and Technology Facilities Council, UK
The planned High Luminosity upgrade to the LHC will require stronger focusing of the beam in the interaction regions. To achieve this, the inner triplet quadrupoles will be replaced with new magnets having larger gradient and aperture. In this new focusing regime the quadrupole fringe fields are expected to have a greater effect on the beam dynamics, due to their large aperture, as compared to the nominal LHC. In this preliminary study, simplified models are used in a tracking code to assess the impact of the fringe fields on the dynamics using frequency map analysis. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO025  
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SUSPSNE003
 Origins of Transverse Emittance Blow-up during the LHC Energy Ramp  
TUPRO010   use link to access more material from this paper's primary paper code  
 
  • M. Kuhn, G. Arduini, V. Kain, A. Langner, Y. Papaphilippou, M. Schaumann, R. Tomás
    CERN, Geneva, Switzerland
  
  During LHC Run 1 about 30 % of the potential peak performance was lost due to transverse emittance blow-up through the LHC cycle. Measurements indicated that the majority of the blow-up occurred during the energy ramp. Until the end of LHC Run 1 this emittance blow-up could not be eliminated. In this paper the measurements and observations of emittance growth through the ramp are summarized. Simulation results for growth due to Intra Beam Scattering will be shown and compared to measurements. A summary of investigations of other possible sources will be given and backed up with simulations where possible. Requirements for commissioning the LHC with beam in 2015 after Long Shutdown 1 to understand and control emittance blow-up will be listed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO010  
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SUSPSNE004
 Fast Crab Cavity Failures in HL-LHC  
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  • B. Yee-Rendón, R. Lopez-Fernandez
    CINVESTAV, Mexico City, Mexico
  • J. Barranco García
    EPFL, Lausanne, Switzerland
  • R. Calaga, R. Tomás, F. Zimmermann
    CERN, Geneva, Switzerland
  
  Crab cavities (CCs) are a key ingredient of the High-Luminosity Large Hadron Collider (HL-LHC)  to ensure head on collisions at the main experiments (ATLAS and CMS) and fully profit from the smaller β* provided by the ATS optics. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of few LHC turns and considering the large energy stored in the HL-LHC beam, CC failures represent a serious risk to the LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, necessary to dump the beam.  The simulations assume a realistic steady-state distribution to assess the beam losses for the HL-LHC.  Additionally, some strategies are studied to mitigate the damage caused by the failures.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO003  
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SUSPSNE005
 FCC-ee Final Focus with Chromaticity Correction  
THPRI010   use link to access more material from this paper's primary paper code  
 
  • H. Garcia, R. Tomás, R. Tomás
    CERN, Geneva, Switzerland
  
  A 100 km circular electron-positron collider is considered as one of the possible future high energy facilities. In order to achieve a high luminosity, strong beam focusing at the Interaction Point is used requiring the correction of the chromatic aberrations. In this paper we study preliminary designs of a Final Focus System for the TLEP collider with chromatic correction. Beam orbit stability and dynamic aperture calculations are also presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI010  
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SUSPSNE006
 Towards a Low Alpha Lattice for the ALBA Storage Ring  
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  • M. Carlà, G. Benedetti, Z. Martí, F. Pérez
    CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
  
  Funding: CELLS-ALBA
A proposal of a low alpha lattice for the ALBA third generation light source is presented. Opposed to most of other machines, belonging to the same category, ALBA employs an optimized lattice making use of combined function dipoles. This has permitted a very compact design stripped out of all not strictly necessary quadrupoles resulting in a lack of flexibility. For such a reason the common approaches used in many other synchrotrons can not be directly applied to ALBA and a different strategy has to worked out. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO089  
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SUSPSNE007
 Low Emittance Storage Ring Design for CANDLE project  
MOPRO047   use link to access more material from this paper's primary paper code  
 
  • G.S. Zanyan, V. Sahakyan, A. Sargsyan, V.M. Tsakanov
    CANDLE, Yerevan, Armenia
  
  The most effective way to increase the brilliance of synchrotron light sources is the reduction of beam emittance. To improve the CANDLE synchrotron light source performance, a new low emittance facility has been designed with the account of the new developments in magnets fabrication technology of last decade. The lattices for the booster and storage rings are re-designed keeping the geometrical layout of the facilities. The new design provides the beam emittance in storage ring below 5nm with sufficient dynamic aperture. This report presents the main design considerations, the linear and non-linear beam dynamics aspects of the modified facility performance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO047  
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SUSPSNE008
 Studies on LPWA-based Light Sources driven by a Transverse Gradient Undulator  
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  • T. Chanwattana, R. Bartolini, A. Seryi
    JAI, Oxford, United Kingdom
  • R. Bartolini
    DLS, Oxfordshire, United Kingdom
  
  The Accelerator Science Laboratory (ASL) is under development at the John Adams Institute in Oxford with the aim of fostering advanced accelerator concepts and applications. The option to install a LPWA based light source driven by a transverse gradient undulator is being investigated. This report presents the accelerator physics, FEL studies and the performance expected from such a facility.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO032  
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SUSPSNE009
 Methods for the Optimization of a Tapered Free-Electron Laser  
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  • A.W.L. Mak, F. Curbis, S. Werin
    MAX-lab, Lund, Sweden
  
  In a free-electron laser (FEL), the technique of wiggler tapering enables the sustained growth of radiation power beyond the initial saturation. With the goal to develop an X-ray FEL in the terawatt power regime, it is important to utilize this technique and optimize the taper profile, giving the wiggler parameter as a function of the distance along the wiggler line. This work examines two methods of optimization, which are based on the theoretical analysis by Kroll, Morton and Rosenbluth (KMR). Using the numerical simulation code GENESIS, the methods are applied to a case for the possible future FEL at the MAX IV Laboratory in Lund, Sweden, as well as a case for the LCLS-II.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO023  
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SUSPSNE010
 Electron-bunch Shaping for Coherent Compton Scattering  
THPRO033   use link to access more material from this paper's primary paper code  
 
  • J.E. Thorne, P. Piot, I. Viti
    Northern Illinois University, DeKalb, Illinois, USA
  • P. Piot
    Fermilab, Batavia, Illinois, USA
  
  Producing high-quality x rays could have important applications to high-precision medical imaging and national security. Inverse Compton scattering involving the head-on collision of a relativistic electron bunch with a high-power laser offers a viable path toward the realization of a compact x-ray source. A method consisting in reflecting a short-pulse laser onto a “relativistic mirror” (a moving thin sheet of electrons) has been proposed and recently demonstrated as a way to enhance the back-scattered photon flux by operating in the coherent regime. In this contribution we present particle-in-cell numerical simulations of the inverse Compton scattering process and especially investigate the impact of the laser-pulse and electron-beam distributions that could substantially improve the x-ray production via coherent emission.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO033  
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SUSPSNE011
 Comparison of the Detection Performance of Three Nonlinear Crystals for the Electro-optic Sampling of a FEL-THz Source  
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  • B. Wu, L. Cao, Q. Fu, P. Tan, Y.Q. Xiong
    HUST, Wuhan, People's Republic of China
  
  The detector of a FEL-THz source at HUST is now in the physical design stage. The electro-optic (EO) sampling method will be employed for the coherent detection. The performances of three widely used EO crystals will be evaluated and compared numerically in the time domain detection: zinc telluride (ZnTe), gallium arsenide (GaAs) and gallium phosphide (GaP). The phase matching properties are analyzed to find the appropriate probe wavelength. The EO detection response is calculated to select the suitable crystal thickness and to discuss the detection ability of each crystal.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO017  
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SUSPSNE012
 Position of Maximum in Quantum Spectrum of Synchrotron Radiation  
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  • A.N. Burimova, D.M. Gitman
    IFUSP, Sao Paulo, Brazil
  • V.G. Bagrov
    Institute of High Current Electronics, Tomsk, Russia
  
  Funding: FAPESP
In the framework of quantum theory, we consider the condition for radiation maximum shift between harmonics of SR spectrum for scalar and spinor particles. Since quantum spectrum is discrete and finite, one can find values of radiation parameters such that the maximum in radiation spectrum stays at highest harmonic. It turns out that there exists a "quantization" of magnetic field associated with shift of maximum from one harmonic to another. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO041  
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SUSPSNE013
 Beam Dynamic Effect of Multi-period Robinson Wiggler in Taiwan Photon Source  
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  • C.W. Huang
    NTHU, Hsinchu, Taiwan
  • C.-S. Hwang
    NSRRC, Hsinchu, Taiwan
  • S.-Y. Lee
    IUCEEM, Bloomington, Indiana, USA
  
  Robinson wiggler is a special insertion device that can be used to decrease natural emittance of the Taiwan Photon Source (TPS) storage ring. There are four poles in one set of Robinson Wiggler and each pole has combined with dipole and quadrupole field strength. The dipole field strength multiply quardupole field strength in each pole should be negative. This Robinson wiggler can change damping partition number and then affect the emittance. This study will evaluate practicability of reducing the emittance of TPS storage ring by muti-period Robinson wiggler and will be installed in the 7 m long-straight section. One period of the traditional Robinson Wiggler include four poles with different field polarity. In the same length, the mult-period Robinson Wiggler have many period in one set of Robinson Wiggler that is different from the traditional Robinson wiggler. Due to the traditional Robinson wiggler can not be effective to improve emittance in TPS storage ring (the efficiency is only 7%). So we adopt to use muti-period Robinson wiggler, the efficiency can be up to 37%, and the linear matching result is better than one period Robinson Wiggler.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO046  
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SUSPSNE014
 Simulating the Production and Effects of Dark Currents in MICE Steps V and VI  
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  • C. Hunt, J. Pasternak, M.A. Uchida
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  
  Funding: STFC
The completion of the international Muon Ionisation Cooling Experiment (MICE) Step V will involve the construction, commissioning and use of RF cavity and Coupling Coil (RFCC) Modules. The RFCCs consist of 4 RF cavities and a solenoid magnet, and are expected to act as a source of potentially damaging electrons (dark currents) and X-rays. Ongoing work to create a high-statistics simulation of the dark current production, within RF cavities, is described. Current results predict the energy and angular spectra of emitted electrons for an RFCC, and include particle tracking, realistic field maps and ionisation energy losses in cavity windows. Individual electron emitters, parametrised by the Fowler-Nordheim equation, are used and are user-definable, allowing potential worst-case scenarios to be simulated and upper/lower limits for the total dark current to be estimated. These data are being used within the MICE Analysis and User Software (MAUS) to estimate the potential detector backgrounds and the damage that may be inflicted upon the scintillating fibre trackers. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI003  
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SUSPSNE015
 nuSTORM Horn Optimization Study  
TUPRI005   use link to access more material from this paper's primary paper code  
 
  • A. Liu, A.D. Bross, D.V. Neuffer
    Fermilab, Batavia, Illinois, USA
  
  The efficiency of using magnetic horns as a pion collection device has been recognized by several neutrino projects. In the study, we began with a “NuMI-like” horn, which was applied to collect the secondary pions from bombarding the target with 120 GeV/c protons in the nuSTORM proposal. The necessity of optimizing the horn for a non-conventional neutrino beamline like the nuSTORM pion beamline was then acknowledged. This paper presents a detailed description of the optimization objectives, the Multi-objective Genetic Algorithm developed for this specific purpose, and the results of the optimization. With the full G4beamline simulation results, the success of the optimization provides an increase of 16\% in the useful muons in the ring. This methodology can be applied to any neutrino beamline configuration.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI005  
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SUSPSNE016
 The LIGHT Beamline at GSI: Shaping Intense MeV Proton Bunches from a Compact Laser-driven Source  
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  • S. Busold, O. Deppert, M. Roth
    TU Darmstadt, Darmstadt, Germany
  • V. Bagnoud, A. Blazevic, S. Busold
    HIJ, Jena, Germany
  • V. Bagnoud, A. Blazevic, S. Busold, D. Schumacher
    GSI, Darmstadt, Germany
  • C. Brabetz
    IAP, Frankfurt am Main, Germany
  • F. Kroll
    TU Dresden, Dresden, Germany
  • F. Kroll
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiation Physics, Dresden, Germany
  
  Laser-based proton acceleration as a source of high intensity multi-MeV-range proton bunches became subject of extensive research during the last 15 years and is discussed as potential candidate for various applications. However, their usage often requires special ways of beam shaping first, as the particles are emitted in a wide energy spectrum and with a large divergence angle from the laser matter interaction point. To handle these characteristics, a test stand has been build at GSI Darmstadt, using a pulsed high field solenoid and a radiofrequency cavity to produce intense collimated proton bunches with low energy spread from a TNSA source. In recent experiments, energy compression of an intense proton bunch around 10 MeV central energy to an energy spread of less than 3% could be demonstrated. The particle numbers were in access of 109 protons and the bunch duration was only a few nanoseconds. Even shorter bunches and thus higher particle intensities are possible. This compact laser-driven proton beamline, available now at GSI, will be introduced and latest experimental results presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME030  
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SUSPSNE017
 Demonstration of Gigavolt-per-meter Accelerating Gradients using Cylindrical Dielectric-lined Waveguides  
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  • B.D. O'Shea, G. Andonian, K.L. Fitzmorris, J. Harrison, J.B. Rosenzweig, O. Williams
    UCLA, Los Angeles, California, USA
  • M.J. Hogan, V. Yakimenko
    SLAC, Menlo Park, California, USA
  
  We present here the results of measurements made showing ~1 GV/m accelerating fields using a hollow dielectric-lined waveguide. The results are comprised of measurement of the energy loss of a high charge (~3 nC) ultrashort (~200 fs), ultra relativistic (20 GeV) beam and concomitant auto-correlation interferometeric techniques to obtain the frequency content of simultaneously generated coherent Cherenkov radiation (CCR). Experiments were conducted at the Facility for Advanced aCcelerator Experimental Tests (FACET) at the SLAC National Laboratory using metal-coated sub-millimeter diameter, ten-centimeter long fused silica tubes. We present simulation and theoretical results in support of the conclusions reached through experiment. These results build on previous work to provide a path towards high gradient accelerating structures for use in compact accelerator schemes, future linear colliders and free-electron lasers.  
slides icon Slides SUSPSNE017 [2.349 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUOBB02  
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SUSPSNE018
 Scaling of TNSA-accelerated Proton Beams with Laser Energy and Focal Spot Size  
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  • L. Obst, S. Kraft, J. Metzkes, U. Schramm, K. Zeil
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiation Physics, Dresden, Germany
  
  By focusing an ultra-short high-intensity laser pulse on a solid target, pulses of protons and other positively charged ions with energies of several 10 MeV per nucleon are generated. The properties of these particle beams such as their energy and absolute number are highly dependent on experimental conditions like laser and target parameters. In order to achieve principal comparability between different experimental campaigns at the Draco laser system at the Helmholtz-Zentrum Dresden-Rossendorf, a reference setup for the laser ion acceleration experiment was established. A configuration is sought in which proton beams of reproducible characteristics are generated. To ensure a high stability of the proton spectra, the application of longer focal length parabolas (f ~ 1000 mm) will be tested for this setup, according preparatory studies being presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME033  
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SUSPSNE019
 Development on On-chip Radiation Source using Dielectric Laser Accelerator  
TUPME037   use link to access more material from this paper's primary paper code  
 
  • S. Otsuki
    The University of Tokyo, Tokyo, Japan
  • K. Koyama, M. Yoshida
    KEK, Ibaraki, Japan
  • Y. Matsumura
    University of Tokyo, Tokyo, Japan
  • S. Mima
    RIKEN, Japan
  • M. Uesaka
    The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
  
  Funding: This work was partly supported by KAKENHI, Grant-in-Aid for Scientific Research (C) 24510120.
One of the state-of-the-art acceleration schemes, where high intensity laser pulses are modulated by dielectric grating structure such as quartz to accelerate charged particles, is dielectric laser acceleration (DLA)*. The difference of our DLA concept from other schemes is installation of a prism: the tilted wave-front in a prism shape refractive medium leads the suitable delay to match the phase advance of the electron beam. We plan to apply this method to build an on-chip radiation source which can hit and damage target elements of the cells. Such an application is useful in radiation biology, i.e., for investigation on bystander effects. The x-rays with small radius and adequate intensity required for this goal can be obtained using sub-micron beams from the small accelerating structure at high repetition rate (such as 50 kHz). In addition, the mass productivity of the DLA based on the consumer-grade laser and the photolithography has advantage compared to the conventional RF accelerator using high power klystrons. We will present field simulation and preliminary experimental results for demonstration on our concept of DLA.
* Demonstration of electron acceleration in a laser-driven dielectric microstructure, Nature 2013
** Laser-Based Acceleration of Nonrelativistic Electrons at a Dielectric Structure, Phys. Rev. 2013
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME037  
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SUSPSNE020
 Wakefield excitation via a metasurface-loaded waveguide  
TUPME038   use link to access more material from this paper's primary paper code  
 
  • E. Sharples
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • R. Letizia
    Lancaster University, Lancaster, United Kingdom
  
  Funding: Work supported by STFC Quota Studentship grant ST/K520133/1
A metallic waveguide loaded with layers of complementary split ring resonator (CSRR) based metasurface is presented for accelerator and coherent source applications. This structure presents left handed behaviour arising from the strong electrical response of CSRRs which form the metasurface and the transverse field confined between the closely positioned metasurface layers. The loaded waveguide structure is known to have a TM-like mode at 5.47GHz suitable for acceleration. In this paper, the results of wakefield simulations are presented and a narrow band excitation identified around the frequency of the TM-like mode, indicating strong coupling between the beam and the field of this mode. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME038  
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SUSPSNE021
 Wide-band Induction Acceleration in the KEK Digital Accelerator  
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  • T. Yoshimoto, X. Liu, K. Takayama
    TIT, Yokohama, Japan
  • T. Adachi, K. Takayama
    Sokendai, Ibaraki, Japan
  • T. Adachi, T. Arai, E. Kadokura, T. Kawakubo, X. Liu, K. Okamura, S. Takano, K. Takayama, T. Yoshimoto
    KEK, Ibaraki, Japan
  • H. Asao, Y. Okada
    NETS, Fuchu-shi, Japan
  • M. Hirose, H. Kobayashi
    Tokyo City University, Tokyo, Japan
  
  Induction synchrotron can accelerate any ion species directly to higher energy without a large pre-accelerator, due to its intrinsic nature that there is no frequency band-width limitation below 1 MHz. KEK digital accelerator (DA) is a small scale prototype of fast cycling induction synchrotron. Recently it has been confirmed that heavy ion beams of mass to charge ratio A/Q = 4 are stably accelerated from 200 keV to a few tens of MeV in this accelerator ring*, where the revolution frequency changes from82 kHz to 1 MHz. Acceleration and beam confinement are separately realized by pulse voltages generated in induction cells (1 to 1 pulse transformers) driven by the switching power supply (SPS)**. Everything is simply maneuvered by controlling of gate signals of solid-state switching elements employed in the SPS. For this purpose, the fully programmed acceleration control system based on the FPGA has been developed. In this paper, the wide-band induction acceleration is presented with experimental results. Further possibilities of beam handling in the induction synchrotron, such as super bunch and novel beam handling techniques, are discussed.
* K.Takayama et al., to be submitted to Phys. Rev. Lett. (2013).
** T.Iwashita et al., Phys. Rev. ST-AB 14, 071301(2011).
 		 
slides icon Slides SUSPSNE021 [8.935 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEOAB02  
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SUSPSNE022
 Room-temperature Burst-mode GHz and THz Pulse-train Photoinjector  
TUPME055   use link to access more material from this paper's primary paper code  
 
  • F.H. Chao, C.H. Chen, K.Y. Huang, Y.-C. Huang, Y.C. Wang, M.H. Wu
    NTHU, Hsinchu, Taiwan
  • P.J. Chou
    NSRRC, Hsinchu, Taiwan
  
  A photoinjector usually generates an electron pulse with few ps pulse duration repeating at 10-100 Hz. The low-pulse rate limits the data rate in a number of applications. Although high-repetition-rate operation is possible from a superconducting accelerator, the high cost and complexity of a superconducting system prevent it from being widely used. In this paper, we present our study toward a burst-mode GHz/THz pulse train photoinjector operating at room temperature. For the GHz operation mode, we self-develop a driver laser system, generating tens of laser pulses at 2.856 GHz in an adjustable 5-10 ns temporal envelope repeating at 10 Hz. Upon illuminating the photocathode with the driver laser, our S-band photoinjector (supported by Tsing Hua University, Beijing) is to generate a GHz electron pulse train with the same temporal structure as that of the driver laser pulses. For the THz operation mode, we illuminate the photocathode with two lasers, one being a typical UV gun-driver laser at 260 nm and the other being a mid-infrared laser at 100 THz. The UV laser induces photoemission and the infrared laser gates the emission current at 100 THz by virtue of the Schottky effect.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME055  
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SUSPSNE023
 Enhanced Laser Ion Acceleration based on Near-Critical Density Plasma Lens  
TUPME052   use link to access more material from this paper's primary paper code  
 
  • Y.X. Geng, J.E. Chen, L.R.F. Li, Y.H. Li, Q. Liao, C. Lin, L.H.Y. Lu, Y.R. Lu, H. Wang, X.Q. Yan, Z.X. Yuan, S. Zhao, W.B. Zhao, Y.Y. Zhao, K. Zhu, B.Y. Zou
    PKU, Beijing, People's Republic of China
  
  The laser prepulse has large effect on ion acceleration driven by high power laser pulse. Recently, simulations show that with proper prepulse parameters, a near critical density pre-plasma can be generated in the front target. When the main laser pulse propagating in this pre-plasma, it can experience transverse Self-focusing, longitudinal profile steepening and prepluse cleaning at the same time, meaning its quality is spontaneously improved by this “plasma lens”.The effects can greatly improve the energy coupling efficiency of laser pulse into accelerated ions. A 3mJ Ti-Sapphire laser system has been built at PKU in order to experimentally study the pre-pulse effect on a solid target. Fluid simulation show that, after hundreds of picoseconds radiated with this laser pulse, the pre-plasma in front of the target will expand to near critical density with tens of micron scale length, which is suitable as a plasma lens to improve the ion acceleration. A laser interferometer system is built to measure the scale length and density evolution of plasma and the optimum condition of the pre-plasma has been searched using both Aluminum target and home-made DLC target.
H.Y.Wang et al, Laser shaping of a relativistic intense, short Gaussian pulse by a plasma lens, PRL, 107,265002, 2011
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME052  
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SUSPSNE024
 Possible Uses of Gamma-rays at Future Intense Positron Sources  
MOPRI006   use link to access more material from this paper's primary paper code  
 
  • A.O. Alrashdi, I.R. Bailey
    Lancaster University, Lancaster, United Kingdom
  • A.O. Alrashdi, I.R. Bailey, D. Newton
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A.O. Alrashdi
    KACST, Riyadh, Kingdom of Saudi Arabia
  • D. Newton
    The University of Liverpool, Liverpool, United Kingdom
  
  Funding: This research is funded in part by STFC grant ST/G008248/1
The baseline design of the ILC (International Linear Collider) positron source requires the production of an intense flux of gamma rays. In this paper we present an investigation of using the gamma ray beam of the ILC for additional applications, including nuclear physics. As a result of changing the collimator shape, as well as the parameters of the undulator magnets, we obtained spectra from numerical simulations using the HUSR/GSR software package. We present results from simulations and a discussion of possible future investigations in this paper. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI006  
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SUSPSNE025
 Plasma Wakefield Acceleration at CLARA PARS  
TUPME081   use link to access more material from this paper's primary paper code  
 
  • K. Hanahoe, Ö. Mete, G.X. Xia
    UMAN, Manchester, United Kingdom
  • D. Angal-Kalinin, J.A. Clarke, J.K. Jones, J.W. McKenzie, B.L. Militsyn, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • D. Angal-Kalinin, J.A. Clarke, J.K. Jones, J.W. McKenzie, Y. Wei, C.P. Welsch, P.H. Williams
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • B. Hidding
    USTRAT/SUPA, Glasgow, United Kingdom
  • J.D.A. Smith
    TXUK, Warrington, United Kingdom
  • Y. Wei, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  
  PARS is a proposed Plasma Accelerator Research Station using the planned CLARA (Compact Linear Accelerator for Research and Applications) electron linear accelerator at Daresbury Laboratory in the UK. In this paper, two- dimensional particle-in-cell simulations based on realistic CLARA beam parameters are presented. The results show that an accelerating gradient of 2.0 GV/m can be achieved over an accelerating length of at least 13 cm. Preliminary simulation results for a two bunch scheme show an energy gain of 70% over a length of 13 cm, giving an average accelerating gradient of 1.2 GeV/m.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPME081  
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SUSPSNE027
 Control of Plasma Flux with Pulsed Solenoid for Laser Ion Source  
MOPRI011   use link to access more material from this paper's primary paper code  
 
  • S. Ikeda, K. Horioka
    TIT, Yokohama, Japan
  • Y. Fuwa, S. Ikeda, M. Kumaki
    RIKEN, Saitama, Japan
  • T. Kanesue, M. Okamura
    BNL, Upton, Long Island, New York, USA
  
  We discuss the behavior of laser-ablation plasma spreading through a pulsed solenoidal field to minimize the beam emittance of laser-ablation ion source (LIS). LIS is expected to produce high-flux and low emittance ion beams from various solid materials in vacuum because of the high drift velocity and low temperature of the ablation plasma due to the adiabatic expansion. However, the ion flux level from the ablation plasma into an extraction gap changes within a pulse and then the shape of the sheath boundary changes transiently. Then, the integrated emittance is larger than the stroboscopic emittance at a certain time slice. To prevent the transient effect, we tried to control the plasma flux with a pulsed solenoidal magnetic field. The field is expected to change the direction of the plasma flow like a lens. By changing the magnetic flux density according to the transient flux level of ablation plasma, we can expect to control the plasma flux at the extraction gap. To investigate the controllability of the plasma flow, we measured the plasma flux as a function of parameters of the pulsed magnetic field. We scanned ion probes along the beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI011  
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SUSPSNE028
 A Compact 2.45 GHz Microwave IOn Source Based High Fluence Irradiation Facility at IUAC, Delhi  
MOPRI008   use link to access more material from this paper's primary paper code  
 
  • N. Kumar, R. Ahuja, R.N. Dutt, D. Kanjilal, P.S. Lakshmy, Y. Mathur, G.O. Rodrigues
    IUAC, New Delhi, India
  
  A compact 2.45 GHz microwave ion source based low energy ion been facility has been developed for performing various experiments in material science and for studies related to plasma physics. The design of the compact microwave source is based on a tunable permanent magnet configuration and is powered by a 2 kW magnetron [1,2]. The double walled, water cooled stainless steel plasma chamber and ridge waveguide have been fabricated using the latest ‘LaserCUSING’ technique. The electron energy distribution functions have been measured in a similar low frequency ion source and validated by model calculations [1]. Extraction of the beam can also be performed at very low voltages in the order of hundreds of volts with high intensities by nullifying the space charge effects with the secondary electrons. The facility will be used for ion implantation, phase formation, surface etching and pattering experiments. The design aspects of the microwave ion source and low energy beam transport system will be presented.
* “Studies on the effect of the axial magnetic field on the x-ray bremsstrahlung in a 2.45 GHz permanent magnet microwave ion source” Narender Kumar et. al. accepted for publication in RSI. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI008  
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SUSPSNE029
 Study on New Method for Generating Highly Charged Ions with Double Pulse Laser Ion Source  
MOPRI009   use link to access more material from this paper's primary paper code  
 
  • T. Shibuya
    TIT, Tokyo, Japan
  • N. Hayashizaki
    RLNR, Tokyo, Japan
  • M. Yoshida
    KEK, Ibaraki, Japan
  
  Laser ion source capable of generating high intensity ions is best for the ion source of RI beam facilities. A great deal of effort has been made on particle number as DPIS. Only few attempts have so far been made at generating highly charged ions. One of previous research has reported that Au+53 ions are produced by PALS laser. "Nonlinear process" mechanisms such as resonance absorption and self-focusing were used for this. However, these methods have limitation due to low repetition rate of the laser. Nd (λ=1064nm, E<1.2J, t~10ns) and Yb laser(λ=1030nm, E<10J, t~500fs) systems is possible to operate at 10 - 50Hz repetition rate. This double pulse laser system, with attainable laser intensity up to about 1017[W/cm2], was used to generate highly charged ions of solid target. First, the Nd laser creates a plasma plume. Next, the Yb laser reheats plasma plume by high intensity pulse at delay time of nanosecond. The properties of ions were investigated mainly on the base of time-of-flight method.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI009  
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SUSPSNE030
 Measurements of the Longitudinal Energy Distribution of Low Energy Electrons  
MOPRI051   use link to access more material from this paper's primary paper code  
 
  • L.J. Devlin, O. Karamyshev, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • L.J. Devlin, O. Karamyshev, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • L.B. Jones, B.L. Militsyn, T.C.Q. Noakes
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  
  Funding: Work supported by STFC Cockcroft Core Grant No.ST/G008248/1
The Transverse Energy Spread Spectrometer (TESS) is an ASTeC experiment designed to measure the energy of electrons from different cathode materials. It is a dedicated test stand for future light sources. A full particle tracking code has been developed in the QUASAR Group, which simulates particle trajectories through TESS. Using this code it is possible to simulate different operational conditions of the experiment and cathode materials. The simulation results can then be benchmarked against experimental data to test the validity of the emission and beam transport model. Within this paper, results from simulation studies are presented and compared against experimental data as a collaboration within the Cockcroft Institute between ASTeC and the QUASAR Group for the case of measuring the longitudinal velocity distribution of electrons emitted from a gallium arsenide cathode using a grid structure as an energy filter. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI051  
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SUSPSNE031
 Laser Systems Generating Short Polarized Electron Bunches at the S-DALINAC  
MOPRI021   use link to access more material from this paper's primary paper code  
 
  • M. Espig, J. Enders, Y. Fritzsche, A. Kaiser, M. Wagner
    TU Darmstadt, Darmstadt, Germany
  
  Funding: Supported by DFG within CRC634 and by the state of Hesse through the LOEWE center HIC for FAIR.
The source of polarized electrons at the superconducting Darmstadt electron linear accelerator S-DALINAC uses photo-emission from strained-layer superlattice-GaAs and bulk-GaAs photocathodes. This system is driven by either 3 GHz gain-switched diode lasers or a short-pulse Ti:Sapphire laser system. Highly polarized electrons are generated with laser light at 780 nm, while blue laser light is used for unpolarized high-current experiments. We present the existing pulsed laser systems and the planned developments for the diode laser system, including, e.g., impedance matching of the diode lasers, gain switching with short electrical pulses and pulsing with a Mach-Zehnder modulator. The pulsed operation is aimed at generating short electron bunches (< 50 ps) at the S-DALINAC with variable repetition rates from some MHz to 3 GHz. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI021  
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SUSPSNE032
 Design and Analysis of an Electron Beam in an Electron Gun for X-Ray Radiotherapy  
MOPRI040   use link to access more material from this paper's primary paper code  
 
  • J.C. Lee, J.-S. Chai, M. Ghergherehchi, H.S. Kim, Y.S. Lee, S. Shin, Y.H. Yeon
    SKKU, Suwon, Republic of Korea
  • B.N. Lee
    KAERI, Dae-jeon, Republic of Korea
  
  Funding: This work was supported by (IT R&D program of MSIP/KEIT [10043897] and MOTIE [13-DU-EE-12]) in KOREA.
Electron linear accelerators are used as x-ray generators for diagnosing the human body. In this paper conceptual design of electron beam for compact electron gun was calculated by using EGN2w and CST-Particle Studio codes. The structure of the electron gun was used for Pierce and diode type and the specification of electron beam was selected as 500 cGy/min. Specifications of designed electron gun were focused on current, beam size and normalized emittance. Optimized beam current, diameter and normalized emittance are 226.88 mA, 0.689 mm (Full width) and 1.03π mm• mrad, respectively by using two simulation codes. Accuracy of simulation was verified by comparison of emitted beam current which has error of 0.74%.
* Subhash C. Sharma et al., Journal of applied clinical medical physics, 8, 3 (2007) 119-125.
* Yuichiro Kamino et al., Med. Phys. 34 (2007) 1797-1808.
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI040  
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SUSPSNE033
 Development of Iridium Cerium Photocathode for the Generation of High-Charge Electron Beam  
MOPRI037   use link to access more material from this paper's primary paper code  
 
  • D. Satoh
    TIT, Tokyo, Japan
  • N. Hayashizaki
    RLNR, Tokyo, Japan
  • T. Natsui, M. Yoshida
    KEK, Ibaraki, Japan
  
  We developed an iridium cerium cathode material made by new production method for multi-purpose electron source. For multi-purpose electron source, we focused on the Ir5Ce compound which has a high melting point (> 2100 K) and a low work function (2.57 eV). This material has some excellent properties as both a thermionic cathode and a photocathode. For example, Ir5Ce thermionic cathode can generate one-order higher electrical current than a LaB6 cathode at the same temperature. Another advantage is that an Ir5Ce thermionic cathode has a lifetime two orders longer than that of a LaB6 thermionic cathode under the same conditions. Moreover, we discovered that this material has a reasonably high quantum efficiency (2.70 × 10−3 @213nm at 1000°C) and long-lifetime (> LaB6) as a photocathode. Our research shows that Ir5Ce compound is optimum material for a thermionic cathode and photocathode. We focused on this good emission properties under the high temperature and we tried to develop a backside electron beam heating system and demonstrate a laser pre-pulse heating for a high current thermionic gun system or high charge photocathode gun.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI037  
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SUSPSNE034
 Study of a C-band Standing-wave Gun for the SwissFEL Injector  
MOPRI043   use link to access more material from this paper's primary paper code  
 
  • M. Schaer, S. Bettoni, A. Citterio, P. Craievich, M. Negrazus, L. Stingelin, R. Zennaro
    PSI, Villigen PSI, Switzerland
  
  The baseline design of the SwissFEL injector foresees the "PSI Gun 1", a 2.6-cell RF photo-cathode gun operating at S-band frequency, as the electron source. In this paper a new design is presented where a 5.6-cell C-band gun could replace the PSI Gun 1 with no impact on the rest of the injector setup. A conservative maximum gradient of 135 MV/m at the cathode is assumed which drives the electron beam faster into the relativistic regime and therefore allows to tolerate larger charge densities. The presented solution also foresees a coaxial RF coupling from the cathode side in order to place the gun solenoid as near to the photo-cathode as possible, improving the emittance compensation. Astra simulations showed that the transverse beam brightness can be doubled before the first bunch compressor preserving the low transverse emittance value as compared to the current design for the S-band injector configuration of SwissFEL.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI043  
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SUSPSNE035
 Introducing GunLab – A Compact Test Facility for SRF Photoinjectors  
MOPRI020   use link to access more material from this paper's primary paper code  
 
  • J. Völker, R. Barday, A. Jankowiak, T. Kamps, J. Rudolph, S.G. Schubert, S. Wesch
    HZB, Berlin, Germany
  • A. Ferrarotto, T. Weis
    DELTA, Dortmund, Germany
  • V.I. Shvedunov
    MSU, Moscow, Russia
  • I.Yu. Vladimirov
    MSU SINP, Moscow, Russia
  
  Funding: Work supported by German Bundesministerium für Bildung und Forschung (BMBF contract 05K12CB2 PCHB and 05K10PEA), Land Berlin and grants of Helmholtz Association
Superconducting radio-frequency photoelectron injectors (SRF photoinjectors) are a promising electron source for high brightness accelerators with high average current and short pulse duration like FELs and ERLs. For the upcoming ERL project BERLinPro we want to test and commission different SRF photoinjectors and examine the beam performance of photocathode materials in an independent test facility. Therefore we designed GunLab to characterize the beam parameters from the SRF photoinjectors in a compact diagnostics beamline. In GunLab we want to investigate the complete 6 dimensional phase space as a function of drive laser and RF setup parameters. In this work we present the design and the estimated performance of GunLab. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI020  
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SUSPSNE036
 Feasibility Study of an Ultrafast Electron Diffraction System in NSRRC  
MOPRI044   use link to access more material from this paper's primary paper code  
 
  • P. Wang, K.C. Leou
    NTHU, Hsinchu, Taiwan
  • N.Y. Huang, W.K. Lau, A.P. Lee
    NSRRC, Hsinchu, Taiwan
  
  It has been suggested that the MeV beam generated from a laser-driven photo-cathode rf gun can be used for ultrafast electron diffraction (UED)*. The feasibility of operating the NSRRC photo-cathode rf gun system for ultrashort bunch generation is being investigated. The results of space-charge tracking calculations show that a low emittance, few hundred femtoseconds MeV beam with reasonable bunch charge can be generated for single shot UED experiments. In this report, a preliminary design of this UED system will be discussed.
* X.J. Wang et al., in Proceedings of PAC'03, p.420. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI044  
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SUSPSNE037
 The Design, Construction and Experiments of a RFQ Cold Model at Tsinghua University  
THPRO095   use link to access more material from this paper's primary paper code  
 
  • L. Du, Q.Z. Xing, Y. Yang
    TUB, Beijing, People's Republic of China
  
  Funding: Work supported by National Natural Science Foundation of China (Major Research Plan Grant No. 91126003 and Project 11175096).
The design, construction and experiments of a cold model of one high-current CW RFQ with ramped inter-vane voltage at Tsinghua University are presented in this paper. The 1-meter-long aluminium cold model is chosen to be the same as the low-energy part of the 3-meter-long RFQ. This cold model will be used mainly for the RFQ field study and education. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO095  
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SUSPSNE038
 Beam Dynamics Issues for a Superconducting Linear Accelerator-based High Power Heavy Ion Machine  
THPME148   use link to access more material from this paper's primary paper code  
 
  • J.G. Hwang, E.-S. Kim
    Kyungpook National University, Daegu, Republic of Korea
  • H. Jang, D. Jeon, H.J. Kim, H.J. Kim
    IBS, Daejeon, Republic of Korea
  
  The driver linac of RAON heavy ion accelerator based on the superconducting technology, which consists of a 28 GHz ECR ion source, a low energy beam transport line, a RFQ accelerator, a medium energy beam transport line, a low energy linac(SCL1), a charge stripping section and a high energy linac(SCL2), will produce the stable ion beam from proton with 600 MeV to uranium with 200 MeV/u. Many beam dynamics issues such as beam steering effect due to QWR cavities with the peak electric field of 35 MV/m, emittance growth in charge stripper due to the straggling effect, parametric resonance and envelope instability were verified to design the high power heavy ion machine which can produce the high quality beam. In this presentation, we explain our study results for achieving longitudinal acceptance larger than 27 keV/u-ns for the stable operation and minimizing the emittance growth less than 30 % in the superconducting linac for high quality beam at the in-flight target.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME148  
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SUSPSNE039
 Development of a 72.75 MHz RFQ for the LINCE Accelerator Complex  
THPME037   use link to access more material from this paper's primary paper code  
 
  • A.K. Orduz, C. Bonțoiu, I. Martel, A.C.C. Villari
    University of Huelva, Huelva, Spain
  • A. Garbayo
    AVS, Elgoibar, Spain
  • P.N. Ostroumov
    ANL, Argonne, Illinois, USA
  • A.C.C. Villari
    FRIB, East Lansing, Michigan, USA
  
  Funding: Work partially supported by the Spanish Government (MINECO-CDTI) under program FEDER INTERCONNECTA.
Low-energy acceleration for the LINCE project [1] will be achieved using a 72.75 MHz normal conducting four vanes RFQ designed to give a 460 keV/u boost for A/Q = 7 ions in about 5 m. The vanes are modeled to accommodate windows for a clear separation of the RFQ modes and easy fitting to an octagonal resonance chamber. This article presents the main numerical results of the radio-frequency modeling and computational fluid dynamics (CFD). Particle tracking studies optimized for bunching and acceleration are shown as well.
[1] I. Martel et al., “LINCE: A High Intensity Multi-ion Superconducting Linac for Nuclear Structure and Reactions”, IPAC’14, Dresden, Germany, June 2014, THPME036, These Proceedings. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME037  
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SUSPSNE040
 Local Compensation-rematch for the C-ADS Accelerator Element Failures with Space Charge  
THPME020   use link to access more material from this paper's primary paper code  
 
  • B. Sun, C. Meng, J.Y. Tang, F. Yan
    IHEP, Beijing, People's Republic of China
  
  In order to achieve the required reliability and availability for the C-ADS accelerator, a fault tolerance design is pursued. The effects of cavity and solenoid failure in different locations have been studied and the schemes of compensation by means of local compensation have been investigated. After one cavity failure, by adjusting the settings of the neighbouring cavities and the focusing elements we can make sure that the Twiss parameters and energy are approximately recovered to that of the nominal ones at the matching point. However, the compensation work above is based on the TraceWin code, which has not considered the phase compensation, a code based on MATLAB is under developing to compensate the arrival time at the matching point that the linear space charge effect has also considered.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME020  
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SUSPSNE041
 Delta-Phi Method for the IFMIF-LIPAc SRF-Linac Cavity Tuning  
THPME002   use link to access more material from this paper's primary paper code  
 
  • M. Valette, N. Chauvin
    CEA/IRFU, Gif-sur-Yvette, France
  • P.A.P. Nghiem, D. Uriot
    CEA/DSM/IRFU, France
  
  In order to achieve the upcoming commissioning of the IFMIF-LIPAc prototype accelerator in Rokkasho, the precision and resolution required for all diagnostics must be determined. These specifications will depend on the precision at which the tuning parameters must be set and finally by the tuning errors that can be tolerated on the beam itself. We will here discuss the use of the ∆φ method to tune the SRF-Linac and the resolution requirements it implies for the BPMs. This method, using a relative time of flight measurement to assess the energy of the beam, has the advantages of allowing setting the beam energy and beam longitudinal focusing at once.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME002  
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SUSPSNE042
 Experimental Performance of an E×B Chopper System  
THPME015   use link to access more material from this paper's primary paper code  
 
  • C. Wiesner, H. Dinter, M. Droba, O. Meusel, D. Noll, T. Nowottnick, O. Payir, U. Ratzinger, P.P. Schneider
    IAP, Frankfurt am Main, Germany
  
  Beam operation of an E×B chopper system has started in the Low-Energy Beam Transport (LEBT) section of the accelerator-driven neutron source FRANZ*. The chopper is designed for low-energy high-perveance beams and high repetition rates. It combines a static magnetic deflection field with a pulsed electric compensation field in a Wien filter-type E×B configuration**. Helium ions with 14 keV energy were successfully chopped at the required repetition rate of 257 kHz. The maximum chopped beam intensity of 3.5 mA, limited by the given test ion source, corresponds to a generalized perveance of 2.7·10-3. For the design species and energy, 120 keV protons, this is equivalent to a beam current of 174 mA. Beam pulses with rise times of 120 ns, flat top lengths of 85 ns to 120 ns and Full Width at Half Maximum (FWHM) between 295 ns and 370 ns were experimentally achieved.
* U. Ratzinger et al., Proc. of IPAC2011, San Sebastián, Spain, WEPS040.
** C. Wiesner et al. Proc. of IPAC2012, New Orleans, LA., USA, THPPP074.
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME015  
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SUSPSNE043
 Study of Beam Transport Lines for a Biomedical Research Facility at CERN based on LEIR  
MOPRI095   use link to access more material from this paper's primary paper code  
 
  • D. Abler
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • C. Carli, A. Garonna
    CERN, Geneva, Switzerland
  • K.J. Peach
    JAI, Oxford, United Kingdom
  
  Funding: This work was supported by EU FP7 PARTNER (215840) and ULICE (228436).
The Low Energy Ion Ring (LEIR) at CERN has been proposed to provide ion beams with magnetic rigidities up to 6.7 Tm for biomedical research, in parallel to its continued operation for LHC and SPS fixed target physics experiments. In the context of this project, two beamlines are proposed for transporting the extracted beam to future experimental end-stations: a vertical beamline for specific low-energy radiobiological research, and a horizontal beamline for radiobiology and medical physics experimentation. This study presents a first linear-optics design for the delivery of 1-5 mm FWHM pencil beams and 5 cm x 5 cm homogeneous broad beams to both endstations. High field uniformity is achieved by selection of the central part of a strongly defocused Gaussian beam, resulting in low beam utilisation. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI095  
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SUSPSNE044
 Resonant Slow Extraction in Synchrotrons by Using Anti-symmetric Sextupole Fields  
MOPRI091   use link to access more material from this paper's primary paper code  
 
  • Y. Zou, J.Y. Tang
    IHEP, Beijing, People's Republic of China
  
  This paper proposes a novel method for non-resonant slow extraction by using special anti-symmetric sextupole field in synchrotrons. The method has the potential in applications asking for stable slow extraction and in the halo collimation of very large machine such as LHC. Our studies show that the slow extraction by using anti-symmetric sextupole field has some advantages compared to the normal sextupole field which is the normal extraction method. One of them is that it can work at almost arbitrary tune, so that it can avoid the problem of the intensity variation caused by the ripples of magnet supplies. Studies by Hamiltonian theory and simulations which meet well show that the stable region only depends on the anti-symmetric sextupole field strength and the particles outside will be driven out in two directions which are similar to the second-order resonant extraction but with spiral steps as in the third-order resonance extraction. The beam can be extracted with a very stable intensity by gradually increasing the field strength. The multi-particle simulations by a self-made program have been carried out with a proton lattice designed for proton therapy.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI091  
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SUSPSNE045
 Heavy Ion Induced Desorption Measurements on Cryogenic Targets  
MOPRI105   use link to access more material from this paper's primary paper code  
 
  • Ch. Maurer, D.H.H. Hoffmann
    TU Darmstadt, Darmstadt, Germany
  • L.H.J. Bozyk, H. Kollmus, Ch. Maurer, P.J. Spiller
    GSI, Darmstadt, Germany
  
  Funding: Bundesministerium für Bildung und Forschung FKZ 06DA7031
Heavy-ion impact induced gas desorption is the key process that drives beam intensity limiting dynamic vacuum losses. Minimizing this effect, by providing low desorption yield surfaces, is an important issue for maintaining a stable ultra high vacuum during operation with medium charge state heavy ions. For room temperature targets, investigation shows a scaling of the desorption yield with the beam's near-surface electronic energy loss, i.e. a decrease with increasing energy*,**. An optimized material for a room temperature ion-catcher has been found. But for the planned superconducting heavy-ion synchrotron SIS100 at the FAIR accelerator complex, the ion catcher system has to work in a cryogenic environment. Desorption measurements with the prototype cryocatcher for SIS100 showed an unexpected energy scaling***, which needs to be explained. Understanding this scaling might lead to a better suited choice of material, resulting in a lower desorption yield. An experimental setup for systematic examination of this scaling is presented. The cryogenic beam-induced desorption yield of several materials at different temperatures is examined.
* H. Kollmus et al., AIP Conf. Proc. 773, 207 (2005))
** E. Mahner et al., Phys. Rev. ST Accel. Beams 14, 050102 (2011)
*** L.H.J. Bozyk, H. Kollmus, P.J. Spiller, Proc. of IPAC 2012, p. 3239 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI105  
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SUSPSNE046
 Final Layout and Expected Cleaning for the First Crystal-assisted Collimation Test at the LHC  
MOPRI110   use link to access more material from this paper's primary paper code  
 
  • D. Mirarchi, S. Montesano, S. Redaelli, W. Scandale
    CERN, Geneva, Switzerland
  • F. Galluccio
    INFN-Napoli, Napoli, Italy
  • A.M. Taratin
    JINR, Dubna, Moscow Region, Russia
  
  The installation in the CERN Large Hadron Collider (LHC) of two crystals in the horizontal and vertical planes was accomplished during the present LHC long shutdown (LS1) for crystal collimation studies. An appropriate layout was designed to demonstrate the principle feasibility of crystal collimation at the LHC. Extensive simulation campaigns were made to evaluate different crystal positions and parameters, in order to ensure that the main goals of these first feasibility tests in the LHC are within reach. In this paper, the final layout is presented. An overview of the considerations behind the design choices and the crystal parameters is given, and the expected performance of the system is discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI110  
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SUSPSNE047
 Simulation Study of Beam Halo Collimation in the Heavy-ion Synchrotron SIS 100  
MOPRI106   use link to access more material from this paper's primary paper code  
 
  • I.A. Prokhorov
    TEMF, TU Darmstadt, Darmstadt, Germany
  • O. Boine-Frankenheim, I. Strašík
    GSI, Darmstadt, Germany
  
  Funding: Work is supported by German Federal Ministry of Education and Research (BMBF) contract no. 05P12RDRBM
The FAIR synchrotron SIS-100 will be operated with high-intensity proton and heavy-ion beams. The collimation system should prevent beam loss induced degradation of the vacuum, activation of the accelerator structure and magnet quenches. A conventional two-stage betatron collimation system is considered for the operation with protons and fully-stripped ions. Particle tracking and ion-collimator interaction simulations of the collimation system were performed. The angular and momentum distributions of the scattered halo particles were described using analytical models and numerical tools like ATIMA and FLUKA. MADX was used for the multi-pass tracking simulations. The results obtained for the collimation cleaning efficiency as a function of the ion species and beam energy together with the detailed beam losses distributions along the ring circumference are presented. This work highlights the main aspects of the collimation of fully-stripped ion beams in the intermediate energy range using conventional two-stage systems. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI106  
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SUSPSNE048
 Start-to-end Optic of the FSF Multi-turn ERL Project  
TUPRO036   use link to access more material from this paper's primary paper code  
 
  • T. Atkinson, A.V. Bondarenko, A.N. Matveenko, Y. Petenev
    HZB, Berlin, Germany
  
  Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association VH NG 636 and HRJRG-214
Advanced magnetic optic designs are required to meet the heavy demands of future light sources: diffraction limited emittance, femto-second pulses and low energy spread. This paper highlights the magnetic optic that is presently being investigated in the ERL-simulation group at HZB. The injector optic is based on subtle emittance compensation techniques of space charge dominated beams. The high energy arcs are designed to suppress emittance growth due to CSR through horizontal phase advance manipulation, ISR effects by keeping the radiation integrals small and reduce the degradation due to chromatic aberrations. Optimised Start-to-End beam dynamic simulations are presented. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO036  
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SUSPSNE049
 LHeC IR Optics Design Integrated into the HL-LHC Lattice  
TUPRO070   use link to access more material from this paper's primary paper code  
 
  • E. Cruz Alaniz, M. Korostelev, D. Newton
    The University of Liverpool, Liverpool, United Kingdom
  • E. Cruz Alaniz, M. Korostelev, D. Newton
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • R. Tomás
    CERN, Geneva, Switzerland
  
  Funding: OPAC fellowship funded by European Union under contract PITN-GA-2011-289485
The LHeC is a proposed upgrade to the LHC to provide electron-proton collisions and explore the new regime of energy and intensity for lepton-nucleon scattering. The work presented here investigates optics and layout solutions allowing simultaneous nucleon-nucleon and lepton-nucleon collisions at separate interaction points compatible with the proposed HL-LHC lattice. A first lattice design has been proposed that collides proton beam 2 with the electron beam. The nominal design calls for a β* (beta function in the interaction point ) of 10 cm using an extended version of the Achromatic Telescopic Squeezing (ATS) scheme, and a L* (distance to the inner triplet) of 10 m. Modifying these two parameters, β* and L*, can provide benefits to the current design since the values of these parameters have direct effects on the luminosity, the natural chromaticity and the synchrotron radiation of the electron beam. This work aims to explore the range over which these parameters can be varied in order to achieve the desired goal. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO070  
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SUSPSNE050
 Emittance Increase and Matching along the Tomography Module at PITZ  
TUPRO051   use link to access more material from this paper's primary paper code  
 
  • G. Kourkafas, P. Boonpornprasert, J.D. Good, M. Groß, I.I. Isaev, D.K. Kalantaryan, M. Khojoyan, M. Krasilnikov, D. Malyutin, B. Marchetti, D. Melkumyan, M. Otevřel, T. Rublack, F. Stephan, G. Vashchenko
    DESY Zeuthen, Zeuthen, Germany
  • G. Asova
    INRNE, Sofia, Bulgaria
  • G. Pathak
    Uni HH, Hamburg, Germany
  
  The Photo Injector Test facility at DESY, Zeuthen site (PITZ), focuses on testing, characterizing and optimizing high brightness electron sources for free electron lasers. PITZ is equipped with a number of transverse emittance measurement stations, among which is the Phase Space Tomography (PST) module. A PST measurement requires a specific transport along the tomography lattice, which ideally rotates the beam in the normalized transverse phase space by 180 degrees in equidistant steps. A preceding matching section is used to provide an injection scheme that delivers the necessary beam parameters for the design transport along the tomography lattice. The high charge density and moderate energy of the electron bunch at PITZ contribute to significant space-charge forces which lead to emittance growth and consequent mismatches of the design parameters. This article presents and evaluates measurements of the emittance increase along the matching section of a 1 nC beam at 22 MeV/c under different focusing schemes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO051  
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SUSPSNE051
 Preliminary Design of a LEBT for HIAF Linac at IMP  
TUPRO054   use link to access more material from this paper's primary paper code  
 
  • Y. Yang, Y. He, L.T. Sun, X.Z. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
  
  Funding: National Basic Research Program of China (contract No. 2014CB845500) and the 100 Talents Program of the CAS ( No.  Y214160BR0) and China Nature Science Foundation (contract No. 11221064).
Heavy-Ion Advanced Research Facility (HIAF) is a new project proposed at Institute of Modern Physics (IMP) in China. HIAF project accelerator is composed of intense ion beam sources, injector superconducting LINAC, acceleration and accumulation storage ring, a collection ring and a collider ring. To achieve the ultimate project goal, HIAF accelerator requires the ion source to provide very high intensity of heavy ion beams, such as 1.7 emA 238U34+ with a repetition rate of 5 Hz and pulse length of 0.5 ms. No state-of-the-art ion source can meet the needs. As a baseline of the project, a high performance superconducting ECR ion source, which is designed to be operational at the microwave frequency of 40-60 GHz will be adopted to produce the pulsed beam of interest for the HIAF accelerator. To transport and match the beams from ECR to the downstream RFQ, a low energy beam transport (LEBT) is needed. This paper presents a preliminary design of the LEBT and the beam dynamics in the LEBT. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO054  
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SUSPSNE052
 Energy Calibration and Tune Jumps Efficiency in the pp AGS  
THPRO090   use link to access more material from this paper's primary paper code  
 
  • Y. Dutheil, L. Ahrens, H. Huang, F. Méot, A. Poblaguev, V. Schoefer, K. Yip
    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.
The AGS tune jump system consists of two fast quadrupoles used to accelerate the crossing of 82 horizontal intrinsic spin resonances. The fast tune jump of ΔQh=+0.04 within 100 μs imposes perfect localization of each of the 82 resonant conditions. Imperfect timing of the tune jumps results in lower efficiency of the system and lower transmission of the polarization through the AGS acceleration cycle. Investigations during the end of the pp AGS Run13 revealed weaknesses in the energy measurement at high energy, causing less than optimal timing of the tune jumps. A new method based on continuous polarization measurement to determine the energy during the acceleration cycle has been developed. Strong operational constraints were taken into account to provide a convenient system of energy measurement. This is also used to calibrate the usual determination of the energy based on revolution frequency of the beam or measured dipole magnetic field. This paper shows the tools developed and the results of the first tests during the AGS Run 14. Simulations of the expected tune jumps efficiency using the AGS Zgoubi model are also presented and compared to experimental results. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO090  
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SUSPSNE053
 Beam-beam Effect on the BTF in Bunched Beams  
THPRO060   use link to access more material from this paper's primary paper code  
 
  • P.A. Görgen, O. Boine-Frankenheim
    TEMF, TU Darmstadt, Darmstadt, Germany
  • W. Fischer
    BNL, Upton, Long Island, New York, USA
  
  We present studies on the transverse baseband Beam Transfer Functions (BTFs) in bunched beams at high energies. The goal of the work is to evaluate whether transverse BTFs can be used to diagnose the tune spread arising from transverse nonlinearities such as the beam-beam effect and space charge. We employ an analytic expression to the BTFs of beams under a transverse nonlinear lens arising from a bi-Gaussian charge distribution. We obtain agreement between a simulation model of an electron-lens like configuration and the analytic results. The tune spread for this scenario can be recovered by means of a fit against the analytic expectation. The results are compared with measurements where the beam-beam effect acts as a substitute for the electron lens. A similar behaviour of the BTF is observed. This allows the conclusion that the transverse BTF can be used to diagnose tune spread from an electron-lens. Finally we discuss the problems that arise when trying to recover the tune spread from BTFs of arbitrary non-Gaussian beams and in the presence of coherent beam-beam modes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO060  
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SUSPSNE054
 Characterization of the Longitudinal Wakefields in the MAX IV Linac  
THPRO074   use link to access more material from this paper's primary paper code  
 
  • O. Karlberg, F. Curbis, S. Thorin, S. Werin
    MAX-lab, Lund, Sweden
  
  In the second part of 2014, the 3GeV linac at the MAX IV laboratory will enter its commissioning stage. Equipped with two guns, the linac will act as a full energy injector for the two storage rings and at the same time provide high brightness pulses to a Short Pulse Facility (SPF). Compression in the linac is done in two double achromats with fixed R56 that relies upon the RF phase introduced energy chirp, which in this case is strongly enhanced by the longitudinal wakefields. Since the longitudinal wakefields plays a major role in the compression and bunch shaping they need to be carefully investigated during the commissioning. In this proceeding we will discuss a measurement technique that will be used during commissioning to characterize the longitudinal wakefields and their precise effects on e.g. the bunch shape and the energy spread. Predictions obtained from particle tracking will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO074  
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SUSPSNE055
 Study of the “Particle-in-Cell” Induced Noise on High Intensity Beams  
THPRO058   use link to access more material from this paper's primary paper code  
 
  • F. Kesting, G. Franchetti
    GSI, Darmstadt, Germany
  • U. Ratzinger
    IAP, Frankfurt am Main, Germany
  
  Numerical noise in PIC codes produces artifacts which affects long term beam simulations needed for accelerator as the SIS100. A detailed study on the effect of numerical noise occurring in multi-particle tracking codes is presented. The influence of the granularity of particle distributions and the fineness of the meshes of Poisson solvers on the particle dynamics was studied. These results are used to discuss the effect of the PIC numerical noise in a long term space charge benchmarking study.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO058  
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SUSPSNE056
 High-chromaticity Optics for the MAX IV 1.5 GeV Storage Ring  
THPRO075   use link to access more material from this paper's primary paper code  
 
  • T. Olsson, S.C. Leemann
    MAX-lab, Lund, Sweden
  
  The MAX IV facility currently under construction in Lund, Sweden will include a 1.5 GeV storage ring. To prevent head-tail instability, the negative natural chromaticities of the MAX IV 1.5 GeV storage ring have been corrected to positive values using sextupole gradients in the focusing quadrupoles along with dedicated sextupole magnets. To allow adjustment of the chromaticity correction, weak correction sextupoles have been inserted into the lattice. A high-chromaticity optics has been developed for the MAX IV 1.5 GeV storage ring in case instability issues arise during commissioning. Two chromatic sextupole families were used to correct the linear chromaticity. The tune footprint was then tailored using the remaining two sextupole families with the goal of maximizing dynamic aperture and Touschek lifetime. This paper describes the recently developed high-chromaticity optics for the MAX IV 1.5 GeV storage ring and discusses performance limitations of the optics constrained by available gradient strength in the sextupoles.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO075  
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SUSPSNE058
 A Precise Beam Dynamics Model of the PSI Injector 2 to Estimate the Intensity Limit  
TUPRI031   use link to access more material from this paper's primary paper code  
 
  • A.M. Kolano, R.J. Barlow
    University of Huddersfield, Huddersfield, United Kingdom
  • A. Adelmann, C. Baumgarten
    PSI, Villigen PSI, Switzerland
  
  We describe a precise beam dynamics model of the production set up of the Injector 2 Cyclotron at the Paul Scherrer Institut (PSI). Injector 2 is a 72 MeV separate-sector cyclotron producing a high intensity proton beam up to 2.7 mA CW, which is then injected into the 590 MeV Ring Cyclotron. The model includes space charge and is calculated for optimised matched initial conditions. It has been verified with measurements. Based on this model we estimate the limits to the intensity obtainable from Injector 2. The precise beam dynamics model is based on the OPAL (Object Oriented Parallel Accelerator Library) simulation code, a tool for charged-particle optics calculations in large accelerator structures and beam lines including 3D space charge.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI031  
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SUSPSNE059
 Geometric Beam Coupling Impedance of LHC Secondary Collimators  
TUPRI049   use link to access more material from this paper's primary paper code  
 
  • O. Frasciello, S. Tomassini, M. Zobov
    INFN/LNF, Frascati (Roma), Italy
  • A. Grudiev, N. Mounet, B. Salvant
    CERN, Geneva, Switzerland
  
  Funding: Work supported by European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404
The High Luminosity LHC project is aimed at increasing the LHC luminosity by an order of magnitude. One of the key ingredients to achieve the luminosity goal is the beam intensity increase. In order to keep under control beam instabilities and to avoid excessive power losses a careful design of new vacuum chamber components and an improvement of the present LHC impedance model are required. Collimators are the main impedance contributors. Measurements with beam have revealed that the betatron coherent tune shifts were by about a factor of 2 higher with respect to the theoretical predictions based on the current model. Up to now the resistive wall impedance has been considered as the major impedance contribution for collimators. By carefully simulating their geometric impedance we show that for the graphite collimators with half-gaps higher than 10 mm the geometric impedance exceeds the resistive wall one. In turn, for the tungsten collimators the geometric impedance dominates for all used gap values. Hence, including the geometric collimator impedance into the LHC impedance model enabled us to reach a better agreement between the measured and simulated collimator tune shifts. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI049  
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SUSPSNE060
 The Proton Synchrotron Transverse impedance model  
TUPRI059   use link to access more material from this paper's primary paper code  
 
  • S. Persichelli, N. Biancacci, S.S. Gilardoni, M. Migliorati, E. Métral, B. Salvant
    CERN, Geneva, Switzerland
  
  The current knowledge of the transverse impedance of the CERN Proton Synchrotron (PS) has been established by theoretical computations, electromagnetic simulations and beam-based measurements at different energies. The transverse coherent tune and phase advance shifts as a function of intensity have been measured in order to evaluate the total effective transverse impedance and its distribution in the accelerator. In order to understand the beam dynamics, the frequency dependence of the impedance budget has also been evaluated considering the individual contribution of several machine devices. 3D models of many PS elements have been realized to perform accurate impedance simulations, while resistive wall and indirect space charge impedances have been evaluated with theoretical and numerical computations. Finally comparisons between the total budget and the measurement results are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI059  
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SUSPSNE061
 Numerical Study of the Microbunching Instability at UVSOR-III: Influence of the Resistive and Inductive Impedances  
TUPRI042   use link to access more material from this paper's primary paper code  
 
  • E. Roussel, S. Bielawski, C. Evain, C. Szwaj
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  • M. Adachi, M. Katoh, S.I. Kimura, T. Konomi
    UVSOR, Okazaki, Japan
  • M. Hosaka, Y. Takashima, N. Yamamoto
    Nagoya University, Nagoya, Japan
  • K.S. Ilin, J. Raasch, A. Scheuring, M. Siegel, P. Thoma
    KIT, Karlsruhe, Germany
  • H. Zen
    Kyoto University, Kyoto, Japan
  
  At high charge, relativistic electron bunches circulating in storage rings undergo an instability, the so-called microbunching or the CSR (Coherent Synchrotron Radiation) instability. This instability is due to the interaction of the electrons with their own radiation and leads to the formation of microstructures (at millimeter scale) in the longitudinal phase space. Thanks to a new type of detector, based on superconducting thin film YBCO, it is now possible to observe directly these microstructures and follow their temporal evolution*. These experimental observations open a new way to make severe comparisons with theory. Here we present results of the modeling of the dynamics at UVSOR-III using a one dimensional Vlasov-Fokker-Planck equation. We show that to obtain a relatively good agreement between numerical simulations and experiments, we have to take into account several types of impedance such as the shielded CSR impedance but also the resistive and inductive impedances.
* First Direct, Real Time, Recording of the CSR Pulses Emitted During the Microbunching Instability, using Thin Film YBCO Detectors at UVSOR-III, IPAC2014 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI042  
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SUSPSNE062
 Quantification of Geometric Uncertainties in Single Cell Cavities for BESSY VSR using Polynomial Chaos  
MOPME018   use link to access more material from this paper's primary paper code  
 
  • J. Heller, T. Flisgen, C. Schmidt, U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
  
  Funding: Federal Ministry for Research and Education Germany under contract 05K13HR1
The electromagnetic properties of SRF cavities are mostly determined by their shape. Due to fabrication tolerances, tuning and limited resolution of measurement systems, the exact shape remains uncertain. In order to make assessments for the real life behaviour it is important to quantify how these geometrical uncertainties propagate through the mathematical system and influence certain electromagnetic properties, like the resonant frequencies of the structure's eigenmodes. This can be done by using non-intrusive straightforward methods like Monte-Carlo (MC) simulations. However, such simulations require a large number of deterministic problem solutions to obtain a sufficient accuracy. In order to avoid this scaling behaviour, the so-called polynomial chaos (PC) expansion is used. This technique allows for the relatively fast computation of uncertainty propagation for few uncertain parameters in the case of computationally expensive deterministic models. In this paper we use the PC expansion to quantify the propagation of uncertain geometry on the example of single cell cavities used for BESSY VSR as well as to compare the obtained results with the MC simulation. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME018  
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SUSPSNE063
 Matrix Integration of ODEs for Spin-orbit Dynamics Simulation  
MOPME011   use link to access more material from this paper's primary paper code  
 
  • A.N. Ivanov, Y. Senichevpresenter
    FZJ, Jülich, Germany
  
  MODE (Matrix integration of Ordinary Differential Equations) is a software package that provides nonlinear matrix maps building for spin-orbit beam dynamics simulation. In this article we briefly describe the developed integrated development environment features and present computational comparison with other simulation tools. MODE mathematical model is based on Newton-Lorentz and T-BMT equations that are expanded to Taylor series up to the necessary order of nonlinearity. The numerical algorithm is based on matrix presentation of Lie propagator. Spin-orbit simulation results of MODE are compared with results of COSY Infinity and OptiM. MODE provides a flexible graphic user interface, code auto complete technology and visual designer for accelerators. There is also a possibility to generate codes in different programming languages and parallelization techniques.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME011  
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SUSPSNE064
 A High Precision Particle-moving Algorithm for Particle-in-cell Simulation of Plasma  
MOPME023   use link to access more material from this paper's primary paper code  
 
  • X.F. Li, D.Z. Chen, D. Li, H.K. Yue
    HUST, Wuhan, People's Republic of China
  
  A new particle-moving algorithm for particle-in-cell simulation of plasma is developed based on the Linear Multistep Method. The conventional and the new algorithms are investigated by numerical experiments, which are conducted in three typical fashions of the electron motions in electromagnetic fields, that is, cyclotron in homogeneous magnetic field, drift in field and motions in inhomogeneous magnetic field. The new algorithm not only improves the accuracy but also relaxes the time step condition for the simulation. It can increase the computation efficiency.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME023  
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SUSPSNE066
 A New Tool for Automated Orbit and Spin Motion Analysis  
MOPME012   use link to access more material from this paper's primary paper code  
 
  • D. Zyuzin
    FZJ, Jülich, Germany
  
  There are a lot of tools to simulate beam dynamics in accelerators of various types. Many of them are intended to use for specific purposes, and there are universal codes that can simulate both orbit and spin motion in magnetic and electrostatic structures. To start using these codes beam physicist first should have learn syntax, know features and methods how to describe lattice and beams in this particular code. Output data structures of different simulation programs are also vary and depend on peculiarities of each program. This paper proposes a new tool for automated generation and execution of input files for simulation programs and for data analysis of output data. The developed tool allows to describe a lattice, calculate different lattice parameters (like tunes) using simulation program, track particles inside the lattice and analyze various parameters of output data (like beam depolarization). Simulations and analysis can be done in parallel using built-in parallelization mechanisms, and all results can be stored in the database and can be easily fetched when needed. The tool is used to simulate beam and spin dynamics in different lattices to increase spin coherence time.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME012  
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SUSPSNE067
 Beam Trip Analysis by Bunch-by-bunch BPM System in BEPCⅡ  
THOAA01   use link to access more material from this paper's primary paper code  
 
  • Q.Y. Deng, J.S. Cao, J. Yue
    IHEP, Beijing, People's Republic of China
  
  A new bunch-by-bunch beam position measurement prototype system has been designed and built to monitor and analysis beam trip in the BEPCⅡ(Beijing Electron-Positron ColliderⅡ) machine. The fast ADC and programmable FPGA can obtain the beam information bunch-by-bunch, so we can analyze base on both time domain and frequency domain. In this paper we will presentation the system architecture and discuss some beam trip analysis result, such as beam instability, tune drifting, RF breakdown, and so on.  
slides icon Slides SUSPSNE067 [0.999 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THOAA01  
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SUSPSNE068
 High-accuracy Diagnostic Tool for Electron Cloud Observation in the LHC based on Synchronous Phase Measurements  
THPME174   use link to access more material from this paper's primary paper code  
 
  • J.F. Esteban Müller, P. Baudrenghien, T. Mastoridis, E.N. Shaposhnikova, D. Valuch
    CERN, Geneva, Switzerland
  
  Electron cloud effects such as heat load in the cryogenic system, pressure rise and beam instabilities are among the main limitations for the LHC operation with 25 ns spaced bunches. A new observation tool was developed to monitor the e-cloud activity and has been successfully used in the LHC during Run 1 (2010-2012). The power loss of each bunch due to the e-cloud can be estimated using very precise bunch-by-bunch measurement of the synchronous phase shift. In order to achieve the required accuracy, corrections for reflection in the cables and some systematic errors need to be applied followed by a post-processing of the measurements. Results show clearly the e-cloud build-up along the bunch trains and its evolution during each LHC fill as well as from fill to fill. Measurements during the 2012 LHC scrubbing run reveal a progressive reduction in the e-cloud activity and therefore a decrease in the secondary electron yield (SEY). The total beam power loss can be computed as a sum of the contributions from all bunches and compared with the heat load deposited in the cryogenic system. The plan to use this method in the LHC operation is also presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME174  
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SUSPSNE069
 An Intensity Measurement Method based on Inorganic Scintillators and Optoelectronic Sensors  
THPME120   use link to access more material from this paper's primary paper code  
 
  • A. Kechler, E. Feldmeier, Th. Haberer, A. Peters, C. Schömers
    HIT, Heidelberg, Germany
  
  The Heidelberg Ion Therapy Center (HIT) is a heavy ion accelerator facility located at the Heidelberg university hospital and intended for cancer treatment with heavy ions and protons. Currently ionization chambers with highly sensitive charge amplifiers are regularly used for intensity measurements of the high-energy ion beams. A new intensity measuring method will be presented based on the combination of fluorescent light from inorganic scintillators and an optoelectronic sensor with adjacent electronics as an alternative to the ionization chambers. A special measurement set-up with a large-area Si PIN-diode and adapted optics was investigated with respect to signal dynamics, resolution and linearity. The experimental results with proton and carbon beams will be presented in detail. Worth mentioning is a variation in sensitivity relating to the position of the beam spot, which could be reduced to some percent only.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME120  
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SUSPSNE070
 Status of Diamond Detector Development for Beam Halo Investigation at ATF2  
THPME092   use link to access more material from this paper's primary paper code  
 
  • S. Liu, P. Bambade, F. Bogard, J-N. Cayla, H. Monard, C. Sylvia, T. Vinatier
    LAL, Orsay, France
  • N. Fuster-Martínez
    IFIC, Valencia, Spain
  • I. Khvastunov
    National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine
  • T. Tauchi, N. Terunuma
    KEK, Ibaraki, Japan
  
  Funding: Chinese Scholarship Council
We are developing a diamond detector for beam halo and Compton spectrum diagnostics after the interaction point (IP) of ATF2, a low energy (1.3 GeV) prototype of the final focus system for ILC and CLIC linear collider projects. Tests of a 500 μm thick sCVD diamond detector with a dimension of 4.5 mm×4.5 mm have been carried out with radioactive sources and with electron beam from PHIL low energy (<10 MeV) photo-injector at LAL. The tests at PHIL were done with different beam intensities in air, just after the exit window at the end of the beam line, to test the response of the diamond detector and the readout electronics. We have successfully detected signals from single electrons, using a 40 dB amplifier, and from an electron beam of 108 electrons, using a 24 dB attenuator. A diamond sensor with 4 strips has been designed and fabricated for installation in the vacuum chambers of ATF2 and PHIL, with the aim to scan both the beam halo (with 2 strips of 1.5 mm×4 mm) and the beam core (with 2 strips of 0.1 mm×4 mm) transverse distributions. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME092  
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SUSPSNE071
 General Consideration for Button-BPM Design  
THPME126   use link to access more material from this paper's primary paper code  
 
  • A.R. Molaee, M.Sh. Shafiee
    ILSF, Tehran, Iran
  • M. Mohammadzadeh
    Shahid Beheshti University, Evin, Tehran, Iran
  • M. Samadfam
    Sharif University of Technology (SUT), Tehran, Iran
  
  In order to design Button Beam Position Monitors (BPMs) for synchrotron facilities, one algorithm by C# have been developed which can calculate all required parameters to analyze optimal design based on vacuum chamber and button dimensions. Beam position monitors are required to get beam stabilities on submicron levels. For this purpose, different parameters such as capacitance, sensitivity versus bandwidth, intrinsic resolution, induced charge and voltage on buttons are calculated. Less intrinsic resolution and high sensitivity and capacitance are desired. To calculate induced charge and voltage on each button, Poisson's equation has been solved by Green method. For sensitivities calibration, two-dimensional map of BPM response is obtained theoretically and compared with the CST simulation map. Results show a good agreement where as their difference is less than 5%.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME126  
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SUSPSNE072
 Generation and Diagnosis of Ultrashort Electron Bunches from a Photocathode RF Gun Linac  
THPME132   use link to access more material from this paper's primary paper code  
 
  • I. Nozawa, M. Gohdo, K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida
    ISIR, Osaka, Japan
  • H. Kobayashi
    KEK, Ibaraki, Japan
  
  Ultrashort electron bunches are essential for time-resolved measurement methods such as pulse radiolysis* from the viewpoint of time resolutions. On the other hand, generation of electro-magnetic wave in the THz range using short electron bunches has been investigated**. Frequency spectra of coherent transition radiation (CTR) emitted by an electron bunch depend on bunch form factor (BFF), which is expressed by Fourier coefficients of longitudinal distribution in the electron bunch. In this study, the bunch length measurement was demonstrated by analyzing THz-waves generated by CTR. Femtosecond electron bunches were generated by a laser photocathode RF gun linac and magnetic bunch compressor. THz-waves generated by CTR, which was emitted on an interface of an aluminum mirror along the beam trajectory, were transported to a Michelson interferometer. The bunch length was measured by analyzing interferogram, which was an infrared detector output as a function of a moving mirror position. Finally, the bunch length was measured according to fitting curves for the interferogram near the centerburst***. Minimum bunch length of 1.3 fs was obtained at a bunch charge of ~1 pC.
*J. Yang et al., Nucl. Instrum. Meth. A 556, 52 (2006).
**K. Kan et al., Appl. Phys. Lett. 99, 231503 (2011).
***A. Murokh et al., Nucl. Instrum. Meth. A 410 (1998).
 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME132  
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SUSPSNE073
 Double Diffraction Radiation Target Interferometry for Micro-train Beam Diagnostics  
THPME159   use link to access more material from this paper's primary paper code  
 
  • D.A. Shkitov, A. Potylitsynpresenter
    TPU, Tomsk, Russia
  • A.S. Aryshev, J. Urakawa
    KEK, Ibaraki, Japan
  
  Funding: This work was supported by grant of Russian Ministry of Education and Science program “Nauka” number 2.1799.2011.
Recently our group starts to investigate a feasibility of double diffraction radiation (DR) target interferometry for non-invasive micro-train beam diagnostics at KEK: LUCX facility. Double DR target consists of two metal plates and one of them can be moved relative to another along the beam trajectory. Micro-train beam is a sequence of short electron bunches with sub-ps spacing. As it was shown* double DR target can be used for such a beam diagnostics measuring DR yield versus plates displacement. The obtained tuning curve (interferogram) allows to determine a number of bunches within the micro-train and spacing between them. In order to design a reliable device for this aim we have to take into account different double DR target interferometer plate’s adjustment inaccuracies. These inaccuracies can be as follows: inaccuracies in the mutual adjustment of plates tilt angles to the beam trajectory, outer plate edge shift along the beam trajectory and other. The influence of the bunch form-factor shape is also considered. We investigated double DR target preparation accuracy requirements in order to minimize measurements uncertainties and increase interferometer resolution.
* Skitov D.A. et. al., J. Phys.: Conf. Ser. 517, 012024 (2014). 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME159  
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SUSPSNE075
 Longitudinal Beam Profile Measurements of the Microbunching Instability  
THPME183   use link to access more material from this paper's primary paper code  
 
  • W. Shields, A. Finn, P. Karataev
    JAI, Egham, Surrey, United Kingdom
  • R. Bartolini, I.P.S. Martin, G. Rehm
    DLS, Oxfordshire, United Kingdom
  
  The microbunching instability is a phenomenon characterized by the onset of radiation bursts above a threshold bunch current. These bursts consist of coherent emissions with wavelengths comparable to the bunch length and shorter. The instability has recently been observed at Diamond Light Source, a 3rd generation synchrotron. The operating conditions for triggering the instability at Diamond Light Source are well known, however measuring the spectral content of the resulting emissions is a more challenging investigation. A Michelson interferometer has been installed with the aim of recording the coherent spectrum from the bunches, using ultra-fast response Schottky Barrier Diode detectors. The longitudinal profile of the bunches can be estimated with subsequent analysis.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME183  
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SUSPSNE076
 Measuring Energy Spread Using Beam Screen Monitor and Four Strip-Line Electrodes for Hls II Injector*  
THPME143   use link to access more material from this paper's primary paper code  
 
  • K. Tang, J. Liu, P. Lu, Q. Luo, B.G. Sun, H. Xu, J. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  In order to nondestructively measure the beam energy spread with a beam energy of 0.8GeV in the injector at the upgrade project of Hefei Light Source (HLS II) in real time, a beam energy spread monitor (BESM) using beam position monitor (BPM) with four stripline electrodes has been developed. And a screen monitor (SM) near the BESM is used to measure beam energy spread destructively. This paper introduces in brief the beam position measurement system and beam transverse profile measurement system. The relationship between the transverse size at the BESM and at the SM (Flag3) is discussed in detail in this report. The result shows that energy spread measuring result of BESM and SM is 0.19% and 0.18% respectively. So we can draw a conclusion that the BESM is capable of nondestructively measuring the beam energy spread.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME143  
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SUSPSNE077
 A Novel Approach to Synchrotron Radiation Simulation  
THPME177   use link to access more material from this paper's primary paper code  
 
  • G. Trad, E. Bravin, A. Goldblatt, S. Mazzoni, F. Roncarolo
    CERN, Geneva, Switzerland
  • G. Trad
    LPSC, Grenoble Cedex, France
  
  At the Large Hadron Collider (LHC) at CERN, synchrotron radiation (SR) is used to continuously monitor the transverse properties of the beams. Unfortunately the machine and beam parameters are such that the useful radiation emitted inside a separation dipole, chosen as source, is diffraction limited affecting heavily the accuracy of the measurement. In order to deconvolve the diffraction effects from the acquired beam images and in order to design an alternative monitor based on a double slit interferometer an extensive study of the synchrotron light source and of the optical propagation has been made. This study is based on simulations combining together several existing tools: SRW for the source, ZEMAX for the transport and MATLAB for the "glue" and analysis of the results. The resulting tool is very powerful and can be easily adapted to other synchrotron radiation problems. In this paper the simulation package and the way it is used will be described as well as the results obtained for the LHC and SPS cases.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME177  
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SUSPSNE078
 Experimental Results of a Gas Jet Based Beam Profile Monitor  
THPME134   use link to access more material from this paper's primary paper code  
 
  • V. Tzoganis
    RIKEN Nishina Center, Wako, Japan
  • A. Jeff, V. Tzoganis, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • A. Jeff, V. Tzoganis, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A. Jeff
    CERN, Geneva, Switzerland
  
  Funding: Work supported by the EU under grant agreement 215080, HGF and GSI under contract number VH-NG-328, the STFC Cockcroft Institute Core Grant Mo.ST/G008248/1, and a RIKEN-Liverpool studentship.
A novel, least invasive beam profile monitor based on a supersonic gas jet has been developed by the QUASAR Group at the Cockcroft Institute, UK. It allows the measurement of beam profiles for various particle beams across a range of energies and vacuum levels to be made. A finely collimated neutral gas jet, produced by a nozzle and several skimmers, is injected into a vacuum chamber perpendicular to the main particle beam. Ionization by the primary beam produces ions which are extracted from the interaction region and directed towards an imaging detector. This contribution presents the design of the monitor and first experimental results obtained with a low energy electron beam. It also discusses solutions of previous alignment problems and challenges in the realization of a versatile control and data acquisition system 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME134  
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SUSPSNE079
 Reconstruction of Longitudinal Electrons Bunch Profiles at FACET, SLAC  
THPME093   use link to access more material from this paper's primary paper code  
 
  • M. Vieille Grosjean, J. Barros, N. Delerue, S. Jenzer
    LAL, Orsay, France
  • F. Bakkali Taheri, G. Doucas, I.V. Konoplev, A. Reichold
    JAI, Oxford, United Kingdom
  • C.I. Clarke
    SLAC, Menlo Park, California, USA
  
  The E-203 collaboration is testing a device on FACET at SLAC to measure the longitudinal profile of electron bunches using Smith-Purcell radiation. At FACET the electron bunches have an energy of 20GeV and a duration of a few hundred femtoseconds. Smith-Purcell radiation is emitted when a charged particle passes close to the surface of a metallic grating. The set-up installed in FACET consists in four targets (three gratings and a blank) on a carrousel on one side and eleven pyroelectric detectors on the opposite side, the beam passing between. At the moment, the measurement is averaged over a hundred pulses or more. We have studied the stability of the measurement from pulse to pulse and the resolution of the measure depending on the number of grating used.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME093  
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SUSPSNE080
 Length Measurement of High-brightness Electron Beam thanks to the 3-Phase Method  
THPME095   use link to access more material from this paper's primary paper code  
 
  • T. Vinatier, C. Bruni, S. Chancé, P.M. Puzo
    LAL, Orsay, France
  
  The goal of 3-phase method is to determine the length of an electron beam without dedicated diagnostics by varying the measurement conditions of its energy spread, through a change in the RF phase of an accelerating structure. The originality here comes from the fact that it is applied on high-brightness electron beams of few MeV generated by RF photo-injectors. It allows testing the accuracy of 3-phase method, since the length to reconstruct is known as being that of the laser pulse generating the beam. It requires establishing the longitudinal transfer matrix of a RF photo-injector, which is difficult since the electron velocity vary from 0 to relativistic during its path*. The 3-phase method in RF photo-injector has been simulated by ASTRA and PARMELA codes, validating the principle of the method. First measurement has been done on PHIL accelerator at LAL, showing a good agreement with the expected length. I will then show results obtained at PITZ with a standing wave booster and a comparison with those coming from a Cerenkov detector. Finally, measurements at higher energy performed on the SOLEIL LINAC with travelling wave accelerating structures will be exposed.
* : K-J. Kim, “RF and Space Charge Effects in Laser-Driven RF Electron Guns”, Nucl. Instr. Meth., A275, 201 (1989) 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME095  
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SUSPSNE081
 Radiation of a Charged Particle Bunch Moving in the Presence of Planar Wire Structure  
THPME157   use link to access more material from this paper's primary paper code  
 
  • V.V. Vorobev, S.N. Galyamin, A.V. Tyukhtin
    Saint-Petersburg State University, Saint-Petersburg, Russia
  
  Funding: Work was supported by "Dynasty" Foundation, the Grant of the President of Russian Federation (No. 273.2013.2) and the Russian Foundation for Basic Research (Grant No. 12-02-31258).
The structure under consideration represents a set of long thin parallel wires which are placed in a plane with fixed spacing. The wires can exhibit a limited conductivity. If the period of the structure is much less than the typical wavelength, the structure’s influence can be described with help of the averaged boundary conditions*. The main attention is given to the case when the bunch flies through the grid in the orthogonal direction. Radiation of charged particle bunch which have small transversal size and limited longitudinal one is studied. Analytical expressions for volume and surface waves are given for the bunches with arbitrary longitudinal profile. A separate analysis is performed for the particular case of the plane which is ideally conducting in only one direction. It is shown that the surface wave is similar, in some way, to the radiation field of the bunch moving in a wire metamaterial**. It is demonstrated that the detection of surface waves can be used to estimate the longitudinal sizes of bunches. Typical numerical results for bunches of different shapes and structures with different parameters are given.
* M.I. Kontorovich et al, Electrodynamics of Grid Structures (Moscow, 1987).
** V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Let., 108, 184801 (2012).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME157  
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SUSPSNE083
 High Availability Software Architecture of C-ADS Control System  
THPRO110   use link to access more material from this paper's primary paper code  
 
  • P.F. Wang, J.S. Cao, Q. Ye
    IHEP, Beijing, People's Republic of China
  
  The control system of Accelerator Driven Sub-critical System (ADS) should be a high-availability (HA) system with fault tolerant architecture, due to the potential utilizations of the ADS, such as separating and transmuting irradiated nuclear fuel. This paper discusses the HA software architecture of ADS control system which mainly composed by four softwares, which are 1) low floor communication and control system–-EPICS [1], 2) hierarchal programming framework of the accelerator–XAL [2], 3) monitoring and operating large scale control systems–Control System Studio (CSS) [1], 4) data storage and service infrastructure–HA database and server cluster. In addition, the recent development of ADS control system is briefly introduced in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO110  
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SUSPSNE084
 Development of a Low-latency, High-precision, Intra-train Beam Feedback System Based on Cavity Beam Position Monitors  
THOAA02   use link to access more material from this paper's primary paper code  
 
  • N. Blaskovic Kraljevic, D.R. Bett, P. Burrows, G.B. Christian, M.R. Davis, Y.I. Kim, C. Perry
    JAI, Oxford, United Kingdom
  
  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 an FPGA-based 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 ~ 1nC separated in time by c. 280ns. The system has been used to demonstrate beam stabilisation to below the 100nm level. Results of the latest beam tests, aimed at even higher performance, will be presented.  
slides icon Slides SUSPSNE084 [2.050 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THOAA02  
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SUSPSNE085
 Emittance Optimisation in the Drive Beam Recombination Complex at CTF3  
TUPRI080   use link to access more material from this paper's primary paper code  
 
  • D. Gamba, F. Tecker
    CERN, Geneva, Switzerland
  • D. Gamba
    JAI, Oxford, United Kingdom
  
  According to the Conceptual Design Report, the power to accelerate the main colliding beams of CLIC is taken from parallel high intensity (100 A), low energy (2.37 GeV) beams. These beams are generated by long trains, accelerated by conventional klystrons and then time-compressed in the so called Drive-Beam Recombination Complex (DBRC). A scaled version of the DBRC has been built at the CLIC Test Facility (CTF3) at CERN in order to prove its principle and study any arising feasibility issues. One of the main constraints is the emittance control during the recombination process. This work presents an overview of the studies ongoing at CTF3, keeping in view possible improvements of the nominal CLIC design. In particular, a generic feedback algorithm to solve (quasi-)linear systems has been implemented and used in order to optimise the process by tuning the energy of the beam and steer the orbits in the different lines, as well matching the design dispersion. Current results and possible room for further optimisation will be shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI080  
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SUSPSNE086
 Transverse Intra-bunch Feedback in the J-PARC MR  
THOAA03   use link to access more material from this paper's primary paper code  
 
  • K. Nakamura
    Kyoto University, Kyoto, Japan
  • Y.H. Chin, T. Obina, M. Okada, M. Tobiyama
    KEK, Ibaraki, Japan
  • T. Koseki, T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • Y. Shobuda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  We will report the development of a new broadband (bandwidth of around 100MHz) feedback system for suppression of intra-bunch oscillations and reduction of particle losses at the J-PARC Main Ring (MR). A new BPM has been designed based on the exponential coupler stripline type (the diameter of 134 mm and the length of 300 mm) and it is now under fabrication. In this BPM system, the frequency characteristics are corrected using the equalizer as bunch signals are differentiated. The design detail and the performance of the new BPM as well as preparation of newly installed exciter and power amplifiers will be presented. We will also report beam test results of head-tail mode suppression at 3 GeV with the bunch length of 150-250 ns.  
slides icon Slides SUSPSNE086 [1.149 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THOAA03  
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SUSPSNE087
 Virtual Cathode Drive Laser Diagnostics with a Large Dynamic Range for a Continuous Wave SRF Photoinjector  
WEPME001   use link to access more material from this paper's primary paper code  
 
  • E. Panofski, A. Jankowiak, T. Kamps, G. Klemz
    HZB, Berlin, Germany
  
  Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association
In a SRF photoinjector the close relationship between the laser pulse and the generated electron bunch parameters requires continuous monitoring of some of the laser pulse parameters. A laser diagnostic system, called virtual cathode, is a key part of a system that controls the stability of the laser. One of the main challenges for the virtual cathode is to cover the large dynamic range of the photocathode laser between commissioning at 120 Hz and operation at 1.3 GHz repetition rate with constant laser pulse parameters. The design of the virtual cathode as well as first measurements with a photocathode drive laser for the SRF injector test facility GunLab of BERLinPro will be presented. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME001  
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SUSPSNE088
 Ferrite Material Characterization in a Static Bias Field for the Design of a Tunable Cavity  
THPRI053   use link to access more material from this paper's primary paper code  
 
  • J. Eberhardt, F. Caspers, C. Vollinger
    CERN, Geneva, Switzerland
  
  During the development of ferrite-loaded accelerating cavities, the electromagnetic properties of the dispersive ferrite material need to be known. We describe a coaxial short-circuit measurement technique to measure the complex permeability of toroidal-shaped samples (127mm outer and 70mm inner diameter) that are exposed to an external magnetic bias field. The external magnetic bias field is applied perpendicular to the RF magnetic field. With this method it is possible to characterize the frequency dependence of the permeability for a frequency range of 1-100MHz. The dependence of the permeability on the external magnetic bias is presented for the ferrite G-510 from Trans-Tech Inc. and the material characterization is shown in the same frequency range. The measurement results are verified by simulations of the measurement set-up.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI053  
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SUSPSNE089
 Achieving Higher Energies via Passively Driven X-band Structures  
THPRI073   use link to access more material from this paper's primary paper code  
 
  • T. Sipahi, S. Biedron, S.V. Milton
    CSU, Fort Collins, Colorado, USA
  
  Due to their higher intrinsic shunt impedance X-band accelerating structures significant gradients with relatively modest input powers, and this can lead to more compact particle accelerators. At the Colorado State University Accelerator Laboratory (CSUAL) we would like to adapt this technology to our 1.3 GHz L-band accelerator system using a passively driven 11.7 GHz traveling wave X-band configuration that capitalizes on the high shunt impedances achievable in X-band accelerating structures in order to increase our overall beam energy in a manner that does not require investment in an expensive, custom, high-power X-band klystron system. Here we provide the design details of the X-band structures that will allow us to achieve our goal of reaching the maximum practical net potential across the X-band accelerating structure while driven solely by the beam from the L-band system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI073  
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SUSPSNE090
 Design of an Accelerating Tube for a Standing-wave Accelerator based on Genetic Algorithm’s Optimal Calculation  
THPRI048   use link to access more material from this paper's primary paper code  
 
  • Z.X. Tang
    USTC, Hefei, Anhui, People's Republic of China
  • Y.J. Pei
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  A compact medical standing-wave (SW) electron accelerating tube has been designed that operating frequency is 2998MHz, operating mode is π/2, final energy is 6MeV and beam current is 100mA based on genetic algorithm (GA)’s optimal calculation. It employed a bi-periodic structure with nose cone shape. We performed the simulation experiment which proved that GA was feasible and gave a set of geometric parameter with higher shunt impedance. We performed tuning of the whole tube by CST MICROWAVE STUDIO and SUPERFISH and calculation of beam dynamics by ASTRA and Parmela in this paper. The total length of the tube is less than 300mm.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI048  
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SUSPSNE091
 Status of the Vertical Testing of the XFEL Third Harmonic Cavity Series  
WEPRI016   use link to access more material from this paper's primary paper code  
 
  • J.F. Chen, M. Bertucci, A. Bosotti, M. Fusetti, C. Maiano, P. Michelato, L. Monaco, M. Moretti, C. Pagani, R. Paparella, P. Pierini, D. Sertore
    INFN/LASA, Segrate (MI), Italy
  
  The prototype cavities of the XFEL 3rd harmonic system at the XFEL injector have been tested vertically before their final integration into the He tank. The Vertical Test facility has been upgraded in preparation of the series and the results so far obtained are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI016  
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SUSPSNE092
 On the Optimal Design of Elliptical Superconducting Cavities  
WEPRI040   use link to access more material from this paper's primary paper code  
 
  • G. Costanza
    Lund University, Lund, Sweden
  
  In this paper a linear regression analysis is used to analyze the behavior of the inner cell of an elliptical cavity. The aim is to understand how the RF parameters are correlated to each other and how they are affected by the change of the geometric parameters. This is done by fitting the RF data to a linear model. The data is obtained by simulating a set of different inner cells automatically by the use of a script. The results are useful in several ways: first of all the analysis sheds light on the behavior of elliptical cavities, in particular on its limitations. The analysis is carried out in the framework of optimal design so it is useful for the cavity designer since it allows to choose the geometry at an early stage of the design. It is also possible to make predictions on the performance of the cavity which are in very good agreement with the simulations. Such predictions facilitate the design of the accelerator when choosing the type and number of cavities and when writing the specifications for the cavities to be used in the accelerator.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI040  
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SUSPSNE093
 New Insights into Heat Treatment of SRF Cavities in a Low-pressure Nitrogen Atmosphere  
WEPRI064   use link to access more material from this paper's primary paper code  
 
  • D. Gonnella, M. Liepe
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: United States Department of Energy
Recent results from Cornell and FNAL have shown that superconducting RF cavities given a heat treatment in a nitrogen atmosphere of a few mTorr display an increase in Q0 with increasing accelerating field, opposite to the medium field Q slope usually observed. Three cavities was prepared at Cornell using this method and subsequently tested after different amounts of material removal. Cavity performance and material properties were extracted for each cavity and correlated with material removal. This has given new insights into how material properties and the anti-Q slope depend on cavity preparation. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI064  
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SUSPSNE094
 Mechanical Analysis of the XFEL 3.9 GHz Cavities in support of PED Qualification  
WEPRI020   use link to access more material from this paper's primary paper code  
 
  • M. Moretti, P. Pierini
    INFN/LASA, Segrate (MI), Italy
  • A. Schmidt
    DESY, Hamburg, Germany
  
  We present the FEA stress analysis under different mechanical conditions of the XFEL 3.9 GHz superconducting cavities. The analysis is being performed in support of the necessary qualification according to the Pressure Equipment Directive European Norms, for the operating conditions set in the European XFEL project.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI020  
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SUSPSNE095
 Progress of HOM Couplers for CERN SPL Cavities  
WEPRI041   use link to access more material from this paper's primary paper code  
 
  • K. Papke, F. Gerigk
    CERN, Geneva, Switzerland
  • U. van Rienen
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
  
  Funding: Work supported by the Wolfgang-Gentner-Programme of the Bundesministerium für Bildung und Forschung (BMBF)
In this paper we present the progress of the Higher-Order-Mode (HOM) coupler design for the high beta CERN SPL (Superconducting Proton Linac) cavities. This includes the RF transmission behavior as well as mechanical and thermal requirements and their optimizations. Warm RF measurements are presented for the first four high beta SPL Cavities made of bulk niobium. Moreover the first prototype of a HOMcoupler will be introduced and we discuss its characteristics and its tuning possibilities. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI041  
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SUSPSNE096
 Comparison of High Order Modes Damping Techniques for 800 MHz Single Cell Superconducting Cavities  
WEPRI037   use link to access more material from this paper's primary paper code  
 
  • Ya.V. Shashkov, N.P. Sobenin
    MEPhI, Moscow, Russia
  • M. Zobov
    INFN/LNF, Frascati (Roma), Italy
  
  Currently, applications of 800 MHz harmonic cavities in both bunch lengthening and shortening regimes are under consideration and discussion in the framework of the High Luminosity LHC project. In this paper we study electromagnetic characteristics of high order modes (HOM) for a single cell 800 MHz superconducting cavity and arrays of such cavities connected by drifts tubes. Different techniques for the HOM damping such as beam pipe grooves, coaxial-notch loads, fluted beam pipes etc. are investigated and compared. The influence of the sizes and geometry of the drift tubes on the HOM damping is analyzed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI037  
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SUSPSNE097
 Magnetic Field Evaluation of Multipole Permanent Magnets by Harmonic Coil with Novel Calibration Technique  
TUPRO094   use link to access more material from this paper's primary paper code  
 
  • R. Kitahara, Y. Fuwa, Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  
  Quadrupole magnets for ILC final focus should be strong enough with the restriction on the external radius to let the disrupted out-going beam pass by, while vibration of the magnetic center has to be highly avoided to keep the nm sized beam focusing stable at the interaction point a few meter downstream from the lens. Gluckstern's 5-ring PMQ singlet seems a good candidate for this point of view. In order to fabricate a good 5-ring singlet, property of each ring has to be good enough. A harmonic coil system, which has 24-bit ADC’s for high resolution, was developed. Current noise level of the system is less than 10-5, which is supposed to be improved by reducing mechanical vibration of the ball bearings. We demonstrated the evaluation method of coil wire position with magnetic field from pin point magnet, so that the accuracy of the method was comparable to um scale. We measured the prototype 5-ring PMQ singlet and evaluated harmonic components. This result was compared with the data measured at KEK.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO094  
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SUSPSNE099
 Rare-Earth End Magnets of a Miniature Race-Track Microtron and their Tuning  
TUPRO100   use link to access more material from this paper's primary paper code  
 
  • I.Yu. Vladimirov, N.I. Pakhomov, V.I. Shvedunov
    MSU, Moscow, Russia
  • Yu.A. Kubyshin
    UPC, Barcelona, Spain
  • J.P. Rigla
    I3M, Valencia, Spain
  • V.V. Zakharov
    Tehnomag ltd., Kaluga, Russia
  
  We report on the tuning of end magnets of a compact 12 MeV racetrack microtron (RTM) which is under construction at the Technical University of Catalonia. They are magnetic systems composed of four dipoles with the Rare-Earth Permanent Magnet (REPM) material used as a source of the magnetic field. The poles of the magnets are equipped with tuning plungers which allow to adjust the magnetic field level. In the article we describe the tuning procedure and different techniques that were used in order to fulfill strict requirements of the field characteristics of the end magnets. It is shown that the obtained magnetic systems provide correct beam trajectories in the 12 MeV RTM.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO100  
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SUSPSNE100
 Preliminary Design of Cooling System for a PrFeB-based Cryogenic Permanent Magnet Undulator Prototype at IHEP  
WEPRI105   use link to access more material from this paper's primary paper code  
 
  • Y.C. Zhang, S.P. Li, H.H. Lu, S.C. Sun, Y.F. Yang
    IHEP, Beijing, People's Republic of China
  
  A circulation cooling system is under progress for a 2-m-long PrFeB-based cryogenic permanent magnet undulator (CPMU) prototype at IHEP. Sub-cooled liquid nitrogen flows through each in-vacuum girder back and forth once. Refrigerant channels for both girders are parallel connected in vacuum chamber. Numerical simulation shows that the cooling system is able to cool down magnet array from 300 K to 83 K. Meanwhile, phase error increases about 0.1 degree.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRI105  
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SUSPSNE101
 Monte Carlo Simulations of Synchrotron Radiation and Vacuum Performance of the Max IV Light Source  
WEPME037   use link to access more material from this paper's primary paper code  
 
  • M. Ady, R. Kersevan
    CERN, Geneva, Switzerland
  • M.J. Grabski
    MAX-lab, Lund, Sweden
  
  In the MAX IV light-source in Lund, Sweden, the intense synchrotron radiation (SR) distributed along the ring generates important thermal and vacuum effects. By means of a Monte Carlo simulation package, which is currently developed at CERN, both thermal and vacuum effects are quantitatively analysed, in particular near the crotch absorbers and the surrounding NEG-coated vacuum chambers. Using SynRad+, the beam trajectory of the upstream bending magnet is calculated; SR photons are generated and traced through the geometry until their absorption. This allows an analysis of the incident power density on the absorber, and to calculate the photon induced outgassing. The results are imported to Molflow+, a Monte Carlo vacuum simulator that works in the molecular flow regime, and the pressure in the vacuum system and the saturation length of the NEG coating are determined using iterations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME037  
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SUSPSNE102
 Systematic Measurement of the Pumping Capabilities of Cryogenic Surfaces  
WEPME028   use link to access more material from this paper's primary paper code  
 
  • F. Chill, O.K. Kester
    IAP, Frankfurt am Main, Germany
  • L.H.J. Bozyk, O.K. Kester, P.J. Spiller
    GSI, Darmstadt, Germany
  
  The quality of the beam vacuum is crucial for the stable operation of synchrotrons with high intensity heavy ions. Cryogenic surfaces are capable of pumping residual gases by cryocondensation until the saturated vapor pressure (SVP) is reached. Even at LHe temperatures the SVP of hydrogen is too high. If the surface coverage is sufficiently low, residual gas can also be bound by cryosorption, yielding in acceptable low pressures. These pumping capabilities can be described by two parameters, both dependent on surface temperature and coverage: The sticking probability (SP), that is the chance of an impinging gas particle to be bound, and the mean sojourn time (MST) of a particle on the surface. To acquire these parameters, an experimental setup is currently built at GSI. It consists of a cryogenic chamber, cooled by a cold head and a warm part with vacuum diagnostics and gas inlet. It allows monitoring the pumping speed and also the equilibrium pressure of the cryogenic part from which the SP and the MST can be deducted. The results will be used to further improve the accuracy of the dynamic vacuum simulations in cryogenic areas of particle accelerators.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME028  
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SUSPSNE103
 High Frequency Electromagnetic Characterization of NEG properties for the CLIC Damping Rings  
WEPME050   use link to access more material from this paper's primary paper code  
 
  • E. Koukovini-Platia, G. Rumolo, C. Zannini
    CERN, Geneva, Switzerland
  
  Coating materials will be used in the CLIC damping rings (DR) to suppress two-stream effects. In particular, NEG coating is necessary to suppress fast beam ion instabilities in the electron damping ring (EDR). The electromagnetic (EM) characterization of the material properties up to high frequencies is required for the impedance modeling of the CLIC DR components. The EM properties for frequencies of few GHz are determined with the waveguide method, based on a combination of experimental measurements of the complex transmission coefficient S21 and CST 3D EM simulations. The results obtained from a NEG coated copper (Cu) waveguide are presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME050  
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SUSPSNE104
 A Low Energy Electron-Scrapersystem for the S-DALINAC Injector  
MOPRO115   use link to access more material from this paper's primary paper code  
 
  • L.E. Jürgensen, T. Bahlo, C. Burandt, F. Hug, T. Kürzeder, N. Pietralla, T. Schösser, C. Ungethüm
    TU Darmstadt, Darmstadt, Germany
  
  Funding: Work supported by DFG through SFB 634
The S-DALINAC is the superconducting linear accelerator of the Institut für Kernphysik at Technische Universität Darmstadt. It delivers an electron beam with energies up to 130 MeV. In order to improve the energy spread and the energy stability of the beam for further acceleration a new scrapersystem has been developed and installed between the 10 MeV injector and the main linac. The system was designed to ensure an energy spread of dE < 10-03. After installation several tests have taken place, the results will be presented in this work. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO115  
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SUSPSNE105
 Survey Network of NESTOR Facility  
THPME201   use link to access more material from this paper's primary paper code  
 
  • O. Bezditko, V.E. Ivashchenko, I.M. Karnaukhov, A. Mytsykov, O.V. Ryezayev, A.Y. Zelinsky
    NSC/KIPT, Kharkov, Ukraine
  
  For successful operation of X-ray source NESTOR it is necessary that all the focusing elements should be installed in design position according to the designed lattice, which should provide a low emittance value and small beam size at the interaction point . Accuracies of NESTOR electromagnetic elements installation are 100 mkm in the transverse coordinate, 200 mkm in the longitudinal coordinate and 200 mrad for all three rotation freedom. To achieve these objectives coordinate net, which allows us to align the elements, was designed and developed in the hall of the NESTOR storage ring. The whole process is controlled by means of optical instruments and theodolite 3T2KP with angular accuracy of 2" and laser meter system LMS - 100, which measure the distance with micron accuracy. The final errors budget consists of the accuracy of the measuring instruments, the quality of elements manufacture and assembling. A well-planned methodology allows to realize the design parameters of the X-ray generator "NESTOR " and was proved by experiments of the facility.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME201  
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SUSPSNE106
 Yb DOPED HIGH-ENERGY UV ULTRAFAST LASER FOR AREAL FACILITY  
WEPME060   use link to access more material from this paper's primary paper code  
 
  • A. Lorsabyan, A.A. Gevorgyan, B. Grigoryan, A.S. Simonyan
    CANDLE SRI, Yerevan, Armenia
  • V. Clet, A. Courjaud
    Amplitude Systemes, Pessac, France
  • T.K. Sargsyan
    LT-PYRKAL cjsc, Yerevan, Armenia
  
  For electron generation from photocathode the new laser system was developed for the AREAL linear accelerator laboratory. Besides generating electrons using the laser, we plan to provide a laser beam for other experimental stations running in parallel. The performance and capabilities of the laser system including operating frequency, electron generation in multi-bunch regime and other advantages are presented. The outlooks and steps for further upgrade are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME060  
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SUSPSNE107
 Advanced Automatic Frequency Control System for a Dual Energy S-band RF Electron Linear Accelerator  
WEPME077   use link to access more material from this paper's primary paper code  
 
  • S.S. Cha
    UST, Daejeon City, Republic of Korea
  • Y. Kim
    ISU, Pocatello, Idaho, USA
  • B.C. Lee, B.N. Lee, H.D. Park, K.B. Song
    KAERI, Daejon, Republic of Korea
  
  Funding: This work was supported by a National Research Foundation of Korea (NRF) grant funded by the ministry of science ICT & future Planning (No. 2010-0026088), and MOTIE Korea (13-DU-EE-12).
The Radiation Instrumentation Research Division of Korea Atomic Energy Research Institute is developing a 2856 MHz dual energy [9, 6 MeV] s-band RF electron linear accelerator for security inspection. The s-band dual energy electron accelerator generates dual x-ray energy by irradiating a bunched electron beam from the cavity to a tungsten target. By detecting an x-ray, the cargo security inspection system can distinguish between organic and inorganic materials. Synchronization of the resonant frequency between the cavity and RF driver is an important factor for the stable operation of an accelerator. With a low RF driver power using the AFC, stable accelerator operations and a uniform output beam power can be obtained. This indicates that an accurate cargo inspection is possible. We used phase a frequency detector that can detect a wide frequency band and synchronize the resonance frequency between the RF driver and cavity. In this paper, we introduce a more advanced AFC system than a conventional AFC system. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME077  
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SUSPSNE108
 Comparison of an Analytical Model for Lossy Transmission Lines with Measurement Data  
WEPME064   use link to access more material from this paper's primary paper code  
 
  • N. Schmitt
    TEMF, TU Darmstadt, Darmstadt, Germany
  • H. Klingbeil
    GSI, Darmstadt, Germany
  
  This paper deals with the analytical modeling of lossy coaxial transmission lines in the frequency range from 100 kHz to 50 MHz with focus on corrugated coaxial lines with polyethylene foam as dielectric. The considered transmission lines are used in low-level radio frequency (LLRF) systems (< 5 MHz) at GSI. These applications require a high precision in amplitude and phase for the transmitted signals where a detailed knowledge of the line properties is of significant interest. As the corresponding data sheets do not provide appropriate data, the necessary data have been computed. The obtained results from the purely analytical model were then compared with previous measurements for validation purposes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME064  
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SUSPSNE109
 A Multi-leaf Faraday Cup Especially for the Therapy of Ocular Tumors with Protons  
WEPRO082   use link to access more material from this paper's primary paper code  
 
  • C.S.G. Kunert, J. Bundesmann, T. Damerow, A. Denker
    HZB, Berlin, Germany
  • A. Weber
    Charite, Berlin, Germany
  
  Funding: Work supported by German Bundesministerium für Bildung und Forschung and Land Berlin
The Helmholtz-Zentrum Berlin (HZB) and the University Hospital Charité in Berlin provide a treatment of ocular tumors with a proton beam. The 68 MeV proton beam is delivered by the isochronous HZB-cyclotron as main accelerator. Very important in tumor irradiation treatments is the positioning of the radiation field. For the treatment of eye tumors it is even more important, due to the small and sensitive structures in the eye. Therefore, because of the well-defined Bragg peak, a proton beam is a good choice to achieve very constrained fields of dose delivery. Especially the knowledge of the proton beam energy and the proton beam range with a high accuracy is crucial, due to the small critical structures in the eye. A possible solution for a quick and precise measurement of the range of such proton beams is a Multi-Leaf Faraday Cup (MLFC). This work has the task to develop such a MLFC adapted to the special requirements of the eye tumor therapy. An overview of the progress of this work regarding the MLFC principles and issues such as the first technical realization and results will be given. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO082  
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SUSPSNE110
 Backscattering X-ray System by using 950 keV X-band Linac X-ray Source  
WEPRO104   use link to access more material from this paper's primary paper code  
 
  • C. Liu
    The University of Tokyo, Tokyo, Japan
  • T. Fujiwara, M. Uesaka
    The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
  • J. Kusano
    Accuthera Inc., Kawasaki, Kanagawa, Japan
  
  Recently several tunnel collapses have happened in the world. To prevent this kind of accidents, the non-destructive inspection for tunnel is seriously needed. Backscattering X-ray system which makes one-side operation possible is a very important way to solve this problem. But the backscattering X-ray systems using X-ray tubes could only get the superficial information of the concrete target*. Now we are using our 950 keV X-ray source to construct the backscattering X-ray system to detect the deeper part of the concrete target.
*D. Shedlok, T. Edwards, C.Toh, “X-ray Backscatter Imaging for Aerospace Applications”, Review of Progress in Quantitative Nondestructive Evaluation, Volume 30 AIP Conf. Proc. 1335, 509-516, (2011). 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO104  
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SUSPSNE112
 Experimental Determination of Heavy Nuclei Fission Cross-sections under Relativistic Deuterons Irradiation on the Accelerator Complex “Nuclotron” for Purposes of Transmutation and Energy Amplification  
WEPRO109   use link to access more material from this paper's primary paper code  
 
  • V.V. Bukhal, A.A. Patapenka, A.A. Safronava
    JIPNR-Sosny NASB, Minsk, Belarus
  • M. Artiushenko
    NSC/KIPT, Kharkov, Ukraine
  • K.V. Husak
    The Joint Institute of Power and Nuclear Reserach - "SOSNY" NASB, Minsk, Belarus
  • S.I. Tyutyunnikov
    JINR, Dubna, Moscow Region, Russia
  
  Experimental studies of neutron spectra of three different subcritical assemblies driven by an accelerator (Accelerator Driven Systems – ADS) for investigation of the possibility of transmutation and energy amplification have been carried out. The assemblies were constructed in the framework of the international project “Energy and Transmutation of Radioactive Wastes” and experiments with them are running in the Veksler and Baldin Laboratory of High Energy Physics of the Joint Institute for Nuclear Research (Dubna, Russia) at the accelerator complex “Nuclotron”. In this paper the results of measurements of 239Pu(n, f), 235U(n, f), 238U(n, f) and 238U(n,γ) reactions cross-sections and reactions rates using solid state nuclear track detectors and activation gamma-spectroscopy are presented. A comparison of the experimental results with FLUKA calculations is given. The obtained experimental values characterize the neutron spectra in the experimental points and allow the efficiency of the ADS technology for the systems with similar parameters to be evaluated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO109  
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SUSPSNE113
 Power Plant Based on Subcritical Reactor and Proton LINAC  
WEPRO110   use link to access more material from this paper's primary paper code  
 
  • A.G. Golovkina, I.V. Kudinovich, D.A. Ovsyannikov
    St. Petersburg State University, St. Petersburg, Russia
  • A.A. Bogdanov
    KSRC, St. Petersburg, Russia
  
  Nuclear power plant based on accelerator driven subcritical reactor (ADSR) is considered. Such systems demonstrate higher safety because the fission proceeds in subcritical core and necessary neutron flux is reached with external neutrons generated in target of heavy nuclides. In order to efficiently use ADSR for energy production, it’s needed the total power, generated in the reactor, to be greater than power inputs for charged particles acceleration. The plant driven by middle-energy accelerator, which is cheaper than high-energy accelerators, proposed for these purposes, is considered. So it’s necessary to find other ways to amplify reactor power outputs. Thus, the technical solution to increase power gain of small-sized power plant with a linear proton accelerator (energy 300-400 MeV, average current 5 mA) is proposed. Thermal power up to 300 MW was reached.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO110  
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SUSPSNE114
 Fusion Based Neutron Sources for Security Applications: Energy Optimisation  
WEPRO112   use link to access more material from this paper's primary paper code  
 
  • S.C.P. Albright, R. Seviour
    University of Huddersfield, Huddersfield, United Kingdom
  
  There is a growing interest in the use of neutrons for national security. The majority of work on security focuses on the use of either sealed tube DT fusors or fission sources, e.g. Cf-252. Fusion reactions enable the energy of the neutron beam to be chosen to suit the application, rather than the application being chosen based on the available neutron beam energy. In this paper we discuss simulations of fusion reactions demonstrating the broad range of energies available and methods for adapting the neutron beam energy produced by target/projectile combinations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO112  
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SUSPSNE115
 In-situ Characterization of K2CsSb Photocathodes  
MOPRI019   use link to access more material from this paper's primary paper code  
 
  • M. Schmeißer, A. Jankowiak, T. Kamps, S.G. Schubert
    HZB, Berlin, Germany
  • S.G. Schubert
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by German Bundesministerium für Bildung und Forschung contract 05K12CB2 PCHB and Land Berlin.
Alkali antimonide photocathodes with high quantum efficiency hold the promise of delivering electrons for high-brightness injectors. A drift type spectrometer (momentatron) was attached to the HZB preparation system to allow in-situ characterization within short time after fabrication and possibly identify correlations between growth process and cathode performance parameters. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI019  
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