Author: Gatzmaga, S.
Paper Title Page
MOPA87 Design of the Cathode Stalk for the LCLS-II-HE Low Emittance Injector 253
 
  • T. Konomi, W. Hartung, S.H. Kim, S.J. Miller, D.G. Morris, J.T. Popielarski, K. Saito, A. Taylor, T. Xu
    FRIB, East Lansing, Michigan, USA
  • C. Adolphsen, J.W. Lewellen
    SLAC, Menlo Park, California, USA
  • S. Gatzmaga, P. Murcek, R. Xiang
    HZDR, Dresden, Germany
  • M.P. Kelly, T.B. Petersen
    ANL, Lemont, Illinois, USA
  
  Su­per­con­duct­ing ra­dio-fre­quency (SRF) elec­tron guns are at­trac­tive for de­liv­ery of beams at a high bunch rep­e­ti­tion rate with a high ac­cel­er­at­ing field. An SRF gun is the most suit­able in­jec­tor for the high-en­ergy up­grade of the Linac Co­her­ent Light Source (LCLS-II-HE), which will pro­duce high-en­ergy X-rays at high rep­e­ti­tion rate. An SRF gun is being de­vel­oped for LCLS-II-HE as a col­lab­o­ra­tive ef­fort by FRIB, HZDR, ANL, and SLAC. The cav­ity op­er­at­ing fre­quency is 185.7 MHz, and the tar­get ac­cel­er­at­ing field at the pho­to­cath­ode is 30 MV/m. The pho­to­cath­ode is re­place­able. The cath­ode is held by a fix­ture (’cath­ode stalk’) that is de­signed for ther­mal iso­la­tion and par­ti­cle-free cath­ode ex­change. The stalk must allow for pre­cise align­ment of the cath­ode po­si­tion, cryo­genic or room-tem­per­a­ture cath­ode op­er­at­ing tem­per­a­ture, and DC bias to in­hibit mul­ti­pact­ing. We are plan­ning a test of the stalk to con­firm that the de­sign meets the re­quire­ments for RF power dis­si­pa­tion and bi­as­ing. In this pre­sen­ta­tion, we will de­scribe the cath­ode stalk de­sign and RF/DC stalk test plan.  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA87  
About • Received ※ 04 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 18 August 2022 — Issue date ※ 11 September 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA03 Status of the SLAC/MSU SRF Gun Development Project 623
 
  • J.W. Lewellen, C. Adolphsen, R. Coy, L. Ge, F. Ji, M.J. Murphy, L. Xiao
    SLAC, Menlo Park, California, USA
  • A. Arnold, S. Gatzmaga, P. Murcek, R. Xiang
    HZDR, Dresden, Germany
  • Y. Choi, C. Compton, X.-J. Du, D.B. Greene, W. Hartung, S.H. Kim, T. Konomi, S.J. Miller, D.G. Morris, M.S. Patil, J.T. Popielarski, L. Popielarski, K. Saito, T. Xu
    FRIB, East Lansing, Michigan, USA
  • M.P. Kelly, T.B. Petersen
    ANL, Lemont, Illinois, USA
  
  Funding: US Department of Energy.
The LCLS-II-HE pro­ject at SLAC is in­tended to in­crease the pho­ton en­ergy reach of the LCLS-II FEL to at least 20 keV. In ad­di­tion to up­grad­ing the un­du­la­tor sys­tem, and in­creas­ing the elec­tron beam en­ergy to 8 GeV, the pro­ject will also con­struct a low-emit­tance in­jec­tor (LEI) in a new tun­nel. To achieve the LEI emit­tance goals, a low-MTE pho­to­cath­ode will be re­quired, as will on-cath­ode elec­tric fields up to 50% higher than those achiev­able in the cur­rent LCLS-II pho­toin­jec­tor. The beam source for the LEI will be based around a su­per­con­duct­ing quar­ter­wave cav­ity res­o­nant at 185.7 MHz. A pro­to­type gun is cur­rently being de­signed and fab­ri­cated at the Fa­cil­ity for Rare Iso­tope Beams (FRIB) at Michi­gan State Uni­ver­sity. This paper pre­sents the per­for­mance goals for the new gun de­sign, an overview of the pro­to­type de­vel­op­ment ef­fort, cur­rent sta­tus, and fu­ture plans in­clud­ing fab­ri­ca­tion of a "pro­duc­tion" gun for the LEI. 		 
poster icon Poster WEPA03 [4.510 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA03  
About • Received ※ 21 July 2022 — Revised ※ 28 July 2022 — Accepted ※ 08 August 2022 — Issue date ※ 11 August 2022
Cite • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)