Author: Middleman, K.J.
Paper Title Page
TUPSO33 The Commissioning of Tess: An Experimental Facility for Measuring the Electron Energy Distribution From Photocathodes 290
 
  • L.B. Jones, R.J. Cash, B.D. Fell, K.J. Middleman, B.L. Militsyn, T.C.Q. Noakes
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • D.V. Gorshkov, H.E. Scheibler, A.S. Terekhov
    ISP, Novosibirsk, Russia
  
  ASTeC have developed a Transverse Energy Spread Spectrometer (TESS) – an experimental facility to characterise the energy distribution of electrons emitted by a photocathode. Electron injector brightness is fundamentally limited by the width of this distribution or energy spread, and brightness will be increased significantly by reducing the longitudinal and transverse energy spread at source. TESS supports photocathode performance measurements at room and LN2-temperature under illumination from a range of fixed- and variable-wavelength light sources, allowing characterisation of both metal and semiconductor photocathodes. Preliminary work with GaAs* has shown that electron energy spread is dependent on the quantum efficiency (Q.E.) of the photocathode source, and TESS includes a piezo-electric leak valve to allow controlled degradation of the photocathode Q.E. whilst monitoring the energy spread of emitted electrons. This system offers huge potential to support future photocathode R&D work into a range of photocathode materials. Using GaAs photocathodes activated to high levels of Q.E. in our photocathode preparation facility**, we present commissioning results for TESS.
* Proc. IPAC ’12, TUPPD067, 1557-1559
** Proc. IPAC ’11, THPC129, 3185-3187 		 
 
WEPSO04 The Conceptual Design of CLARA, a Novel FEL Test Facility for Ultra-short Pulse Generation 496
 
  • J.A. Clarke, D. Angal-Kalinin, R.K. Buckley, S.R. Buckley, P.A. Corlett, L.S. Cowie, D.J. Dunning, B.D. Fell, P. Goudket, A.R. Goulden, S.P. Jamison, J.K. Jones, A. Kalinin, B.P.M. Liggins, L. Ma, K.B. Marinov, P.A. McIntosh, J.W. McKenzie, K.J. Middleman, B.L. Militsyn, A.J. Moss, B.D. Muratori, H.L. Owen, R.N.C. Santer, Y.M. Saveliev, R.J. Smith, S.L. Smith, E.W. Snedden, M. Surman, T.T. Thakker, N. Thompson, R. Valizadeh, A.E. Wheelhouse, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R. Appleby, R.J. Barlow, H.L. Owen, M. Serluca, G.X. Xia
    UMAN, Manchester, United Kingdom
  • R. Appleby, G. Burt, S. Chattopadhyay, D. Newton, A. Wolski
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • R. Bartolini, S.T. Boogert, A. Lyapin
    JAI, Egham, Surrey, United Kingdom
  • N. Bliss, R.J. Cash, G. Cox, G.P. Diakun, A. Gallagher, D.M.P. Holland, B.G. Martlew, M.D. Roper
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • S.T. Boogert
    Royal Holloway, University of London, Surrey, United Kingdom
  • G. Burt
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • L.T. Campbell, B.W.J. MᶜNeil
    USTRAT/SUPA, Glasgow, United Kingdom
  • A.M. Kolano
    University of Huddersfield, Huddersfield, United Kingdom
  • I.P.S. Martin
    Diamond, Oxfordshire, United Kingdom
  • D. Newton, A. Wolski
    The University of Liverpool, Liverpool, United Kingdom
  • V.V. Paramonov
    RAS/INR, Moscow, Russia
  
  The conceptual design of CLARA, a novel FEL test facility focussed on the generation of ultra-short photon pulses with extreme levels of stability and synchronisation is described. The ultimate aim of CLARA is to experimentally demonstrate that sub-coherence length pulse generation with FELs is viable, and to compare the various schemes being championed. The results will translate directly to existing and future X-ray FELs, enabling them to generate attosecond pulses, thereby extending the science capabilities of these intense light sources. This paper will describe the design of CLARA, pointing out the flexible features that will be incorporated to allow multiple novel FEL schemes to be proven.