Author: Ruiz-Oses, M.     [Ruiz-Osés, M.]
Paper Title Page
MOPPP028 SRF Photoinjector for Proof-of-principle Experiment of Coherent Electron Cooling at RHIC 622
 
  • D. Kayran, S.A. Belomestnykh, I. Ben-Zvi, J.C. Brutus, X. Liang, G.T. McIntyre, I. Pinayev, B. Sheehy, J. Skaritka, T. Srinivasan-Rao, R. Than, J.E. Tuozzolo, Q. Wu, T. Xin
    BNL, Upton, Long Island, New York, USA
  • V. Litvinenko, M. Ruiz-Osés
    Stony Brook University, Stony Brook, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy and by Stony Brook DOE grant DE-SC0005713.
Coherent Electron Cooling (CEC) based on FEL amplifier promises to be a very good way to cool protons and ions at high energies. A proof of principle experiment to demonstrate cooling at 40 GeV/u is under construction at BNL. One of possible sources to provide sufficient quality electron beam for this experiment is a SRF photoinjector. In this paper we discuss design and simulated performance of the photoinjector based on existing 112 MHz SRF gun and newly designed single-cavity SRF linac operating at 704 MHz.
 
 
MOPPP041 Effect of Roughness on Emittance of Potassium Cesium Antimonide Photocathodes 655
 
  • T. Vecchione, J. Feng, H.A. Padmore, W. Wan
    LBNL, Berkeley, California, USA
  • I. Ben-Zvi, M. Ruiz-Osés, L. Xue
    Stony Brook University, Stony Brook, USA
  • D. Dowell
    SLAC, Menlo Park, California, USA
  • T. Rao, J. Smedley
    BNL, Upton, Long Island, New York, USA
 
  Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences of the U. S. Department of Energy, under Contract DE-AC02-05CH11231, KC0407-ALSJNT-I0013, and DE-SC0005713
Here we present first measurements of the effect of roughness on the emittance of K2CsSb photocathodes under high fields. We show that for very thin cathodes the effect is negligible at up to 3 MV/m but for thicker and more efficient cathodes the effect becomes significant. We discuss ways to modify the deposition to circumvent this problem.
 
 
MOPPP049 Deposition and In-Situ Characterization of Alkali Antimonide Photocathodes 670
 
  • X. Liang
    SBU, Stony Brook, New York, USA
  • K. Attenkofer
    ANL, Argonne, USA
  • I. Ben-Zvi, M. Ruiz-Osés
    Stony Brook University, Stony Brook, USA
  • H.A. Padmore, T. Vecchione
    LBNL, Berkeley, California, USA
  • S.G. Schubert
    HZB, Berlin, Germany
  • J. Smedley
    BNL, Upton, Long Island, New York, USA
 
  Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences of the U. S. Department of Energy, under Contract No. KC0407-ALSJNT-I0013, and DE-SC0005713.
Alkali antimonide cathodes have the potential to provide high quantum efficiency for visible light, and are significantly more tolerant of vacuum contaminants than GaAs, so they are attractive for high-average-current photoinjectors to generate high quality electron beams. These cathodes are crystalline; however, standard growth recipes used today do not produce large crystals. We have grown multi-alkali cathodes on silicon and molybdenum substrates with in-situ X-ray diffraction (XRD) and X-ray reflection (XRR) analysis. The correlation of the cathode structure to the growth parameters and quantum efficiency was explored. During the deposition and evaporation of Sb and K layers, the possibility of selective growth of specific crystalline orientation was observed via X-ray diffraction.