• E.R. Harms, T.T. Arkan, H.T. Edwards, M.H. Foley, A. Hocker, T.N. Khabiboulline, M.W. McGee, D.V. Mitchell, A.M. Rowe, N. Solyak
  Fermilab, Batavia
• W. Decking, M. Dohlus, M. Hüning, K. Jensch, G. Kreps, W.-D. Möller, E. Vogel
  DESY, Hamburg

A 4-cavity 3.9 GHz cryomodule has been constructed at Fermilab and delivered to DESY. Its intended use is to linearize the non-linear beam energy-time profile produced by the 1.3 GHz accelerating gradient and thus improve the operating characteristics of FLASH for its users. First cold testing of the module is expected in the near future prior to its installation. We will report on the performance of the cavities, assembly and transport of the module as well as anticipated testing, installation, and commissioning plans.

Slides

Talk

• H.T. Edwards, C.A. Cooper, M. Ge, I.G. Gonin, E.R. Harms, T.N. Khabiboulline, N. Solyak
  Fermilab, Batavia

Five 3.9 GHz 9 cell cavities have been measured for the DESY FLASH module. These cavities were BCP processed and reached gradients of typically about 25 MV/m with Q drop starting at about 20 MV/m. Recently one cell cavities have been processed with EP and at least one has tested to a gradient of 30 MV/m with Q drop starting at about 25 MV/m. We will compare the results and give an update to the thermal analysis in relation to global thermal breakdown at 3.9 GHz.

Poster