Keyword: cryomodule
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MOPSO51 Feasibility of an XUV FEL Oscillator at ASTA FEL, undulator, electron, simulation 88
 
  • A.H. Lumpkin
    Fermilab, Batavia, USA
  • H. Freund
    LANL, Los Alamos, New Mexico, USA
  • M.W. Reinsch
    LBNL, Berkeley, California, USA
 
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
A significant opportunity exists at the Advanced Superconducting Test Accelerator (ASTA) facility presently under construction at Fermilab to enable the first XUV free electron laser (FEL) oscillator experiments. The ultrabright beam from the L-band photoinjector will provide sufficient gain to compensate for reduced mirror reflectances in the VUV-XUV regimes, the 3-MHz micropulse repetition rate for 1 ms will support an oscillator configuration, the SCRF linac will provide stable energy, and the eventual GeV-scale energy with three TESLA-type cryomodules will satisfy the FEL resonance condition in the XUV regime. Concepts based on combining such beams with a 5-cm-period undulator and optical resonator cavity for an FEL oscillator are described. We used the 68% reflectances for normal incidence on multilayer metal mirrors developed at LBNL*. Initial simulations using GINGER with an oscillator module and MEDUSA:OPC show saturation for the 13.4-nm case after 300 and 350 passes, respectively,of the 3000 pulses. Initially, VUV experiments could begin in the 180- to 120-nm regime using MgF2-coated Al mirrors with only one cryomodule installed and beam energies of 250-300 MeV.
*LBNL X-ray optics site: http://xdb.lbl.gov/Section4
 
 
TUOCNO04 Feasibility of CW and LP Operation of the XFEL Linac linac, HOM, cavity, electron 189
 
  • J.K. Sekutowicz, V. Ayvazyan, J. Branlard, M. Ebert, J. Eschke, T. Feldmann, A. Gössel, D. Kostin, I.M. Kudla, W. Merz, F. Mittag, C. Müller, R. Onken, I. Sandvoss, E. Schneidmiller, A.A. Sulimov, M.V. Yurkov
    DESY, Hamburg, Germany
  • W. Cichalewski, A. Piotrowski, K.P. Przygoda
    TUL-DMCS, Łódź, Poland
  • K. Czuba
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  • W. Jałmużna
    Embedded Integrated Control Systems GmbH, Hamburg, Germany
  • J. Szewiński
    NCBJ, Świerk/Otwock, Poland
 
  The European XFEL superconducting linac is based on cavities and cryomodules (CM) developed for TESLA linear collider. The XFEL linac will operate nominally in short pulse (sp) mode with 1.3 ms RF pulses (650 μs rise time and 650 μs long bunch train). For 240 ns bunch spacing and 10 Hz RF-pulse repetition rate, up to 27000 bunches per second can be accelerated to 17.5 GeV to generate uniquely high average brilliance photon beams at very short wavelengths. While many experiments can take advantage of full bunch trains, others prefer an increased to several μ-seconds intra-pulse distance between bunches, or short bursts with a kHz repetition rate. For these types of experiments, the high average brilliance can be preserved only with duty factors much larger than that of the currently proposed sp operation. In this contribution, we discuss progress in the R&D program for future upgrade of the European XFEL linac, namely an operation in the continuous wave (cw) and long pulse (lp) mode, which will allow for more flexibility in the electron and photon beam time structure.  
slides icon Slides TUOCNO04 [8.910 MB]  
 
TUPSO12 RF Design Approach for an NGLS Linac cavity, linac, cryogenics, controls 226
 
  • A. Ratti, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, M. Venturini, R.P. Wells
    LBNL, Berkeley, California, USA
  • C. Adolphsen, C.D. Nantista
    SLAC, Menlo Park, California, USA
  • D. Arenius, S.V. Benson, D. Douglas, A. Hutton, G. Neil, W. Oren, G.P. Williams
    JLAB, Newport News, Virginia, USA
  • C.M. Ginsburg, R.D. Kephart, T.J. Peterson, A.I. Sukhanov
    Fermilab, Batavia, USA
 
  Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a ~2.4 GeV CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts for the cavity and cryostat design operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules, This leverages the extensive experience derived from R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given now to high loaded Q operation and microphonics control, as well as high reliability and expected up time. The work describes the design and configuration of the linac, including choice of gradient, possible modes of operation, cavity design and RF power, as well as the consequent requirements for the cryogenic system.
 
 
TUPSO13 Superconducting Linac Design Concepts for a Next Generation Light Source at LBNL cavity, linac, HOM, controls 229
 
  • J.N. Corlett, J.M. Byrd, L.R. Doolittle, P. Emma, A. Ratti, F. Sannibale, M. Venturini, R.P. Wells, S. Zimmermann
    LBNL, Berkeley, California, USA
  • C. Adolphsen, C.D. Nantista
    SLAC, Menlo Park, California, USA
  • D. Arenius, G. Neil, T. Powers, J.P. Preble
    JLAB, Newport News, Virginia, USA
  • C.M. Ginsburg, R.D. Kephart, A.L. Klebaner, T.J. Peterson, A.I. Sukhanov
    Fermilab, Batavia, USA
 
  Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
The NGLS collaboration is developing design concepts for a multi-beamline soft X-ray FEL array powered by a superconducting linear accelerator, operating in CW mode, with a high bunch repetition rate of approximately 1 MHz. The superconducting linear accelerator design concept is based on existing TESLA and ILC technology, developed for this CW application in a light source. In this paper we describe design options and preferred approaches for the NGLS SRF linac components, cryomodules, and cryosystems.
 
 
TUPSO75 Design Analysis and High Power RF Test of a 3.9 GHz 5-cell Deflecting-mode Cavity in a Cryogenic Operation cavity, simulation, vacuum, coupling 399
 
  • Y.-M. Shin
    Northern Illinois University, DeKalb, Illinois, USA
  • M.D. Church
    Fermilab, Batavia, USA
 
  A 3.9 GHz deflecting mode (π, TM110) cavity has been long used for six-dimensional phase-space beam manipulation tests [1 - 5] at the A0 Photo-Injector Lab (16 MeV) in Fermilab and their extended applications with vacuum cryomodules are currently planned at the Advanced Superconducting Test Accelerator (ASTA) user facility (> 50 MeV). Despite the successful test results, the cavity, however, demonstrated limited RF performance during liquid nitrogen (LN2) ambient operation that was inferior to theoretical prediction. We have been performing full analysis of the designed cavity by analytic calculation and comprehensive system simulation analysis to solve complex thermodynamics and mechanical stresses. The re-assembled cryomodule is currently under the test with a 50 kW klystron at the Fermilab A0 beamline, which will benchmark the modeling analysis. The test result will be used to design vacuum cryomodules for the 3.9 GHz deflecting mode cavity that will be employed at the ASTA facility for beam diagnostics and phase-space control.
[1] D. A. Edwards, LINAC 2002
[2] Y.-E Sun, PRTAB 2004
[3] P. Piot, PRSTAB2006
[4] J. Ruand et al., PRL 2011
[5] Y.-E. Sun, et al., PRL 2010