Author: Vecchione, T.
Paper Title Page
TUYD3 The Quest for the Perfect Cathode 281
 
  • J.W. Lewellen, J. Smedley, T. Vecchione
    SLAC, Menlo Park, California, USA
  • D. Filippetto
    LBNL, Berkeley, California, USA
  • S.S. Karkare
    Arizona State University, Tempe, USA
  • J.M. Maxson
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • P. Musumeci
    UCLA, Los Angeles, California, USA
 
  Funding: U.S. Department of Energy.
The next gen­er­a­tion of free elec­tron lasers will be the first to see the per­for­mance of the laser strongly de­pen­dent on the ma­te­ri­als prop­er­ties of the pho­to­cath­ode. A new in­jec­tor pro­posed for the LCLS-II HE is an ex­am­ple of this rev­o­lu­tion, with the goal of in­creas­ing the pho­ton en­ergy achiev­able by LCLS-II to over 20 keV. We must now ask, what is the op­ti­mal cath­ode, tem­per­a­ture, and laser com­bi­na­tion to en­able this in­jec­tor? There are many com­pet­ing re­quire­ments. The cath­ode must be ro­bust enough to op­er­ate in a su­per­con­duct­ing in­jec­tor, and must not cause con­t­a­m­i­na­tion of the in­jec­tor. It must achieve suf­fi­cient charge at high rep­e­ti­tion rate, while min­i­miz­ing the emit­tance. The wave­length cho­sen must min­i­mize mean trans­verse en­ergy while main­tain­ing tol­er­a­ble lev­els of multi-pho­ton emis­sion. The cath­ode must be ca­pa­ble of op­er­at­ing at high (~30 MV/m) gra­di­ent, which puts lim­its on both sur­face rough­ness and field emis­sion. This pre­sen­ta­tion will dis­cuss the trade space for such a cath­ode/laser com­bi­na­tion, and de­tail a new col­lab­o­ra­tive pro­gram among a va­ri­ety of in­sti­tu­tions to in­ves­ti­gate it.
 
slides icon Slides TUYD3 [1.632 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-TUYD3  
About • Received ※ 02 August 2022 — Revised ※ 04 August 2022 — Accepted ※ 14 August 2022 — Issue date ※ 26 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)