A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Kreps, G.

Paper Title Page
THOARA02 Preparation Phase for the 1.3 GHz Cavity Production of the European XFEL 3633
 
  • W. Singer, S. Aderhold, A. Brinkmann, R. Brinkmann, J.A. Dammann, J. Iversen, G. Kreps, L. Lilje, A. Matheisen, W.-D. Möller, D. Reschke, J. Schaffran, A. Schmidt, J.K. Sekutowicz, X. Singer, H. Weise
    DESY, Hamburg
  • P.M. Michelato
    INFN/LASA, Segrate (MI)
  
 

The prepa­ra­tion phase for the Eu­ro­pean XFEL cav­i­ty pro­duc­tion in­cludes a num­ber of ac­tions. Ma­te­ri­al is­sues: qual­i­fi­ca­tion of high pu­ri­ty nio­bi­um ven­dors, ver­i­fy­ing of large grain ma­te­ri­al as a pos­si­ble op­tion, con­struc­tion of the scan­ning de­vice for the nio­bi­um sheets. Me­chan­i­cal fab­ri­ca­tion is­sues: ac­com­mo­da­tion of the TESLA cav­i­ty de­sign to the XFEL de­mands, de­vice con­struc­tion for RF mea­sure­ment of com­po­nents, in­te­gra­tion of the he­li­um tank and it's weld­ing to the cav­i­ty into the fab­ri­ca­tion se­quence, doc­u­men­ta­tion and data trans­fer, ap­pli­ca­tion of a new high res­o­lu­tion cam­era for in­spec­tion of the in­side sur­face. Treat­ment and RF mea­sure­ment: es­tab­lish­ing the XFEL recipe, in par­tic­u­lar the final sur­face treat­ment (final 40 μm EP or short 10 μm Flash BCP), and the cav­i­ty prepa­ra­tion strat­e­gy (ver­ti­cal ac­cep­tance test with or with­out he­li­um tank weld­ed, with or with­out as­sem­bly of HOM an­ten­nas), con­struc­tion of the cav­i­ty tun­ing ma­chine. About 50 pro­to­type cav­i­ties are pro­duced at the in­dus­try, treat­ed (par­tial­ly in in­dus­try and par­tial­ly at DESY) and RF-test­ed at DESY. The XFEL re­quire­ments are ful­filled with a yield of ap­prox. 90%.

  

slides icon

Slides

 
THPD003 Test and Commissioning of the Third Harmonic RF System for FLASH 4281
 
  • E. Vogel, C. Albrecht, N. Baboi, C. Behrens, T. Delfs, J. Eschke, C. Gerth, M.G. Hoffmann, M. Hoffmann, M. Hüning, R. Jonas, J. Kahl, D. Kostin, G. Kreps, F. Ludwig, W. Maschmann, C. Mueller, P. Nommensen, J. Rothenburg, H. Schlarb, Ch. Schmidt, J.K. Sekutowicz
    DESY, Hamburg
  • H.T. Edwards, E.R. Harms, A. Hocker, T.N. Khabiboulline
    Fermilab, Batavia
  • M. Kuhn
    Uni HH, Hamburg
  
 

Ultra short bunch­es with high peak cur­rent are re­quired for ef­fi­cient cre­ation of high bril­liance co­her­ent light at the free elec­tron laser FLASH. They are ob­tained by a two stage trans­verse mag­net­ic chi­cane bunch com­pres­sion scheme based on ac­cel­er­a­tion of the beam off the rf field crest. The de­vi­a­tion of the rf field's sine shape from a straight line leads to long bunch tails and re­duces the peak cur­rent. This ef­fect will be elim­i­nat­ed by adding the Fer­mi­lab-built third har­mon­ic su­per­con­duct­ing ac­cel­er­at­ing mod­ule op­er­at­ing at 3.9 GHz to lin­earize the rf field. The third har­mon­ic mod­ule also al­lows for the cre­ation of uni­form in­ten­si­ty bunch­es of ad­justable length that is need­ed for seed­ed op­er­a­tion. This paper sum­ma­rizes the re­sults from the first com­plete rf sys­tem test at the cry­mod­ule test bench at DESY and the first ex­pe­ri­ence gained op­er­at­ing the sys­tem with beam in FLASH.