The interaction of the beam with the higher order
modes (HOM) in the TESLA cavities has been studied in
the past at the TESLA Test Facility (TTF) in order to
determine whether the modes with the highest loss factor
are sufficiently damped. The same modes can be used
actively for beam alignment. At TTF2 a first study on the
beam alignment based on the HOM signals has been
made in the first cryo-module, containing 8 accelerating
cavities. Four modes with highest R/Q in the first two
cavities have been monitored. One bunch has been
usually used. The cavity center could be found for each of
the modes. The results are presented in this paper. |
