INFN/LNF, Frascati (Roma)
STAAR/AWR Corporation, Mequon
SLAC, Menlo Park, California
CERN, Geneva
To suppress the vertical beam instability in the CTF3 Combiner Ring caused by vertical trapped modes in the rf deflectors, two new devices have been constructed. In the new structures special antennas absorb the power released by the beam to the modes. They have been realized in aluminium to reduce the costs and delivery time and have been successfully installed in the ring. In the paper we illustrate the electromagnetic design, the realization procedures, the rf measurement and high power test results.
