• T. Zwart, dc. Cheever, N.T. Cliffer, M. Farkhondeh, W. Graves, W. North, C. Tschalaer, D. Wang, D. Wang, F. Wang, A. Zolfaghari, J. van der Laan
  MIT, Middleton, Massachusetts
• H.-D. Gräf
  TU Darmstadt, Darmstadt

A fast ferrite inductive tuner assembly has been constructed for use at the 3 GHz superconducting S-Dalinac accelerator. This device was installed and tested at the S-Dalinac in April 2005. At a fixed accelerating field of 1.4 MV/m using a simple analog control loop the amplitude of the cavity peak-to-peak phase fluctuations with respect to the phase of the incident RF was reduced from 80 degrees to 10 degrees. The 50 Hz noise which dominated the open loop microphonics was reduced by more than 30 dB. The open loop response of the reactive tuner has also been characterized, yielding a tuning range of ?f greater than 300 Hz at a Qext of 1.5e7. The ferrite tuner was then relocated on the waveguide to a distance of (n+1/4)? from the input coupler. This allowed fast control of the coupling with range of Qext from 1.5 - 8e7.

• B. Steiner, W.F.O. Müller, T. Weiland
  TEMF, Darmstadt
• J. Enders, H.-D. Gräf, A. Richter, M. Roth
  TU Darmstadt, Darmstadt

The Superconducting DArmstädter LINear ACcelerator (S-DALINAC) is a 130 MeV recirculating electron accelerator serving several nuclear and radiation physics experiments. For future tasks, the 250 keV thermal electron source should be completed by a 100 keV polarized electron source. Therefore a new low energy injection concept for the S-DALINAC has to be designed. The main components of the injector are a polarized electron source, an alpha magnet, a Wien filter spin-rotator and a Mott polarimeter. In this paper we report over the first simulation and design results. For our simulations we used the TS2 and TS3 modules of the CST MAFIA (TM) programme which are PIC codes for two and three dimensions and the CST PARTICLE STUDIO (TM).