Author: Smedley, J.
Paper Title Page
TUOC3 High QE, Low Emittance, Green Sensitive FEL Photocathodes Using K2CsSb 179
 
  • H.A. Padmore, D. Dowell, J. Feng, T. Vecchione, W. Wan
    LBNL, Berkeley, California, USA
  • I. Ben-Zvi
    Stony Brook University, Stony Brook, USA
  • T. Rao, J. Smedley
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work was supported by the Director, Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy, under Contract No. DE-AC02-05CH11231, KC0407-ALSJNT-I0013, and DE-SC0005713.
We de­scribe the de­vel­op­ment of pho­to­cath­odes based on Potas­sium-Ce­sium-An­ti­monide that sat­isfy many of the key re­quire­ments of fu­ture light sources, such as ro­bust­ness, high quan­tum ef­fi­ciency when ex­cited with vis­i­ble light and low trans­verse emit­tance. We have demon­strated QE of 7% at 532 nm, a nor­mal­ized trans­verse emit­tance of 0.36 μm at 543 nm and 3 MV/m field gra­di­ent[1]. We have also shown that the ma­te­r­ial can be rel­a­tively ro­bust to resid­ual water con­t­a­m­i­na­tion and we have ex­tracted cur­rent den­si­ties of 1 mA/mm2 with very long life­time. We be­lieve that this work is an im­por­tant step for­ward in FEL de­vel­op­ment where high rep­e­ti­tion rate is re­quired.
[1] Applied Physics Letters (submitted)
 
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