Author: Grudiev, A.
Paper Title Page
MOPP023 X-band Technology for FEL Sources 101
MOPOL02   use link to see paper's listing under its alternate paper code  
 
  • G. D'Auria, S. Di Mitri, C. Serpico
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • E. Adli
    University of Oslo, Oslo, Norway
  • A.A. Aksoy, Ö. Yavaş
    Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
  • D. Angal-Kalinin, J.A. Clarke
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • C.J. Bocchetta, A.I. Wawrzyniak
    Solaris, Kraków, Poland
  • M.J. Boland, T.K. Charles, R.T. Dowd, G. LeBlanc, Y.E. Tan, K.P. Wootton, D. Zhu
    SLSA, Clayton, Australia
  • G. Burt
    Lancaster University, Lancaster, United Kingdom
  • N. Catalán Lasheras, A. Grudiev, A. Latina, D. Schulte, S. Stapnes, I. Syratchev, W. Wuensch
    CERN, Geneva, Switzerland
  • W. Fang, Q. Gu
    SINAP, Shanghai, People's Republic of China
  • E.N. Gazis
    National Technical University of Athens, Athens, Greece
  • M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann
    Uppsala University, Uppsala, Sweden
  • X.J.A. Janssen
    VDL ETG, Eindhoven, The Netherlands
  
  As is widely recognized, fourth generation Light Sources are based on FELs driven by Linacs. Soft and hard X-ray FEL facilities are presently operational at several laboratories, SLAC (LCLS), Spring-8 (SACLA), Elettra-Sincrotrone Trieste (FERMI), DESY (FLASH), or are in the construction phase, PSI (SwissFEL), PAL (PAL-XFEL), DESY (European X-FEL), SLAC (LCLS II), or are newly proposed in many laboratories. Most of the above mentioned facilities use NC S-band (3 GHz) or C-band (6 GHz) linacs for generating a multi-GeV low emittance beam. The use of the C-band increases the linac operating gradients, with an overall reduction of the machine length and cost. These advantages, however, can be further enhanced by using X-band (12 GHz) linacs that operate with gradients twice that given by C-band technology. With the low bunch charge option, currently considered for future X-ray FELs, X-band technology offers a low cost and compact solution for generating multi-GeV, low emittance bunches. The paper reports the ongoing activities in the framework of a collaboration among several laboratories for the development and validation of X-band technology for FEL based photon sources.  
 
MOPP024 Perspectives of the S-Band Linac of FERMI 105
 
  • A. Fabris, P. Delgiusto, M. Milloch, C. Serpico
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • A. Grudiev
    CERN, Geneva, Switzerland
  
  The S-band linac of FERMI, the seeded Free Electron Laser (FEL) located at the Elettra laboratory in Trieste, has reached the peak on-crest electron energy of 1.55 GeV required for FEL-2 with the present layout. Different ways are being considered to extend the operating energy of the S-band linac up to 1.8 GeV. At the same time upgrades on the existing systems are investigated to address the requirements of operability of a users facility. This paper provides an overview of the developments that are under consideration and discusses the requirements and constraints for their implementation.  
 
MOPP028 New Criterion for Shape Optimization of Normal-Conducting Accelerator Cells for High-Gradient Applications 114
 
  • K.N. Sjobak, A. Grudiev
    CERN, Geneva, Switzerland
  • E. Adli
    University of Oslo, Oslo, Norway
  
  When optimizing the shape of high-gradient accelerating cells, the goal has traditionally been to minimize the peak surface electric field / gradient, or more recently minimizing the peak modified Poynting vector / gradient squared. This paper presents a method for directly comparing these quan- tities, as well as the power flow per circumference / gradient squared. The method works by comparing the maximum tolerable gradient at a fixed pulse length and breakdown rate that can be expected from the different constraints. The paper also presents a set of 120° phase-advance cells for traveling wave structures, which were designed for the new CLIC main linac accelerating structure, and which are optimized according to these criteria.  
 
MOPP030 CALIFES: A Multi-Purpose Electron Beam for Accelerator Technology Tests 121
 
  • J.L. Navarro Quirante, R. Corsini, W. Farabolini, D. Gamba, A. Grudiev, M.A. Khan, T. Lefèvre, S. Mazzoni, R. Pan, F. Peauger, F. Tecker, N. Vitoratou, K. Yaqub
    CERN, Geneva, Switzerland
  • W. Farabolini, F. Peauger
    CEA/DSM/IRFU, France
  • D. Gamba
    JAI, Oxford, United Kingdom
  • M.A. Khan, K. Yaqub
    PINSTECH, Islamabad, Pakistan
  • J. Ögren, R.J.M.Y. Ruber
    Uppsala University, Uppsala, Sweden
  • N. Vitoratou
    Thessaloniki University, Thessaloniki, Greece
  
  The Compact Linear Collider (CLIC) project aims to accelerate and collide electrons and positrons up to 3 TeV center-of-mass energy using a novel two-beam acceleration concept. To prove the feasibility of this technology the CLIC Test Facility CTF3 has been operated during the last years. CALIFES (Concept d’Accélérateur Linéaire pour Faisceau d’Electron Sonde) is an electron linac hosted in the CTF3 complex, which provides a flexible electron beam and the necessary equipment to probe both the two-beam acceleration concept and novel instrumentation to be used in the future CLIC collider. In this paper we describe the CALIFES Linac and its beam characteristics, present recent test results, outline its future program on two-beam module testing and finally discuss about possible future applications as a multi-purpose accelerator technology test facility.  
 
TUPP033 Effect of Beam-Loading on the Breakdown Rate of High Gradient Accelerating Structures 499
TUPOL08   use link to see paper's listing under its alternate paper code  
 
  • J.L. Navarro Quirante, R. Corsini, A. Degiovanni, S. Döbert, A. Grudiev, O. Kononenko, G. McMonagle, S.F. Rey, A. Solodko, I. Syratchev, F. Tecker, L. Timeo, B.J. Woolley, X.W. Wu, W. Wuensch
    CERN, Geneva, Switzerland
  • O. Kononenko
    SLAC, Menlo Park, California, USA
  • A. Solodko
    JINR, Dubna, Moscow Region, Russia
  • J. Tagg
    National Instruments Switzerland, Ennetbaden, Switzerland
  • B.J. Woolley
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • X.W. Wu
    TUB, Beijing, People's Republic of China
  
  The Compact Linear Collider (CLIC) is a study for a future room temperature electron-positron collider with a maximum center-of-mass energy of 3 TeV. To efficiently achieve such high energy, the project relies on a novel two beam acceleration concept and on high-gradient accelerating structures working at 100 MV/m. In order to meet the luminosity requirements, the break-down rate in these high-field structures has to be kept below 10 per billion. Such gradients and breakdown rates have been demonstrated by high-power RF testing several 12 GHz structures. However, the presence of beam-loading modifies the field distribution for the structure, such that a higher input power is needed in order to achieve the same accelerating gradient as the unloaded case. The potential impact on the break-down rate was never measured before. In this paper we present an experiment located at the CLIC Test Facility CTF3 recently proposed in order to quantify this effect, layout and hardware status, and discuss its first results.  
slides icon Slides TUPP033 [1.970 MB]  
poster icon Poster TUPP033 [2.355 MB]  
 
TUPP127 R&D of X-band Accelerating Structure for Compact XFEL at SINAP 715
 
  • W. Fang, Q. Gu, M. Zhang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  • A.A. Aksoy, Ö. Yavaş
    Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
  • D. Angal-Kalinin, J.A. Clarke
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.J. Bocchetta, A.I. Wawrzyniak
    Solaris, Kraków, Poland
  • M.J. Boland
    SLSA, Clayton, Australia
  • G. D'Auria, S. Di Mitri, C. Serpico
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • T.J.C. Ekelöf, R.J.M.Y. Ruber, V.G. Ziemann
    Uppsala University, Uppsala, Sweden
  • E.N. Gazis
    National Technical University of Athens, Athens, Greece
  • A. Grudiev, A. Latina, D. Schulte, S. Stapnes, W. Wuensch
    CERN, Geneva, Switzerland
  
  One compact hard X-ray FEL facility is being planned at SINAP, and X-band high gradient accelerating structure is the most competetive scheme for this plan. X-band accelerating structure is designed to switch between 60MV/m and 80MV/m, and carries out 6GeV and 8GeV by 130 meters linac respectively. In this paper, brief layout of compact XFEL will be introduced, and in particular the prototype design of dedicated X-band acceleration RF system is also presented.  
 
WEIOA02
 New applications of high-gradient RF linacs  
 
  • A. Grudiev
    CERN, Geneva, Switzerland
  
  An introduction and a short review of the state-of-the-art of high gradient linac research and development in the frame work of linear collider study and beyond will be given. Possible applications of the high gradient linacs in the field of X-ray FELs and medical linacs will be discussed.  
slides icon Slides WEIOA02 [4.583 MB]  
 
THPP013 Prototype Development of the CLIC Crab Cavities 856
 
  • G. Burt, P.K. Ambattu, A.C. Dexter, M. Jenkins, C. Lingwood, B.J. Woolley
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • V.A. Dolgashev
    SLAC, Menlo Park, California, USA
  • P. Goudket, P.A. McIntosh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A. Grudiev, G. Riddone, A. Solodko, I. Syratchev, R. Wegner, W. Wuensch
    CERN, Geneva, Switzerland
  • C. Hill, N. Templeton
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  
  CLIC will require two crab cavities to align the beams to provide an effective head-on collision with a 20 mdeg crossing angle at the interaction point. An X-band system has been chosen for the crab cavities. Three prototype cavities have been developed in order to test the high power characteristics of these cavities. One cavity has been made by UK industry and one has been made using the same process as the CLIC main linac in order to gain understanding of breakdown behaviour in X-band deflecting cavities. The final cavity incorporates mode-damping waveguides on each cell which will eventually contain SiC dampers. This paper details the design, manufacture and preparation of these cavities for testing and a report on their status.  
 
THPP040 A Compact High-Frequency RFQ for Medical Applications 935
 
  • M. Vretenar, A. Dallocchio, V.A. Dimov, M. Garlaschè, A. Grudiev, A.M. Lombardi, S.J. Mathot, E. Montesinos, M.A. Timmins
    CERN, Geneva, Switzerland
  
  In the frame of a new program for medical applications, CERN has designed and is presently constructing a compact 750 MHz Radio Frequency Quadrupole to be used as injector for hadron therapy linacs. The RFQ reaches an energy of 5 MeV in only 2 meters; it is divided into four standardized modules of 500 mm, each equipped with 12 tuner ports and one RF input. The inner quadrant radius is 46 mm and the RFQ has an outer diameter of 134 mm; its total weight is only 220 kg. The beam dynamics and RF design have been optimized for reduced length and minimum RF power consumption; construction techniques have been adapted for future industrial production. The multiple RF ports are foreseen for using either 4 solid-state units or 4 IOT’s as RF power sources. Although hadron therapy requires only a low duty cycle, the RFQ has been designed for 5% duty cycle in view of other uses. This extremely compact and economical RFQ design opens several new perspectives for medical applications, in particular for PET isotopes production in hospitals with two coupled high-frequency RFQs reaching 10 MeV and for Technetium production for SPECT tomography with two RFQs followed by a DTL.  
 
THPP061 RF Design of a Novel S-Band Backward Traveling Wave Linac for Proton Therapy 992
THPOL03   use link to see paper's listing under its alternate paper code  
 
  • S. Benedetti, U. Amaldi
    TERA, Novara, Italy
  • A. Degiovanni, A. Grudiev, W. Wuensch
    CERN, Geneva, Switzerland
  
  Proton therapy is a rapidly developing technique for tumour treatment, thanks to the physical and dosimetric advantages of charged particles in the dose distribution. Here the RF design of a novel high gradient accelerating structure for proton Linacs is discussed. The choice of a linear accelerator lies mainly in its advantage over cyclotron and synchrotron in terms of fast energy modulation of the beam, which allows the implementation of active spot scanning technique without need of passive absorbers. The design discussed hereafter represents a unicum thanks to the accelerating mode chosen, a 2.9985 GHz backward traveling wave mode with 150° phase advance, and to the RF design approach. The prototype has been designed to reach an accelerating gradient of 50 MV/m, which is more than twice that obtained before. This would allow a shorter Linac potentially reducing cost. The complete 3D RF design of the full structure for beta equal to 0.38 is presented. A prototype will be soon produced and tested at high power. This structure is part of the TULIP project, a proton therapy single-room facility based on high gradient linear accelerators.  
slides icon Slides THPP061 [1.537 MB]