Measurements of Complex Permeability and Permittivity of Ferrites for the LHC Injection Kicke

The LHC injection kicker is made by a lumped element delay line using capacitors and single turn inductors. For these inductors different types of ferrites (Philips 8C11 and 4A4) are considered. At the time when this report was written only 4A4 ferrite was available for a prototype kicker construction, as well as for impedance measurements by the wire method. The 4A4 ferrite comes in standard blocks (42 x 54 x 74 mm) which are quite expensive, so there were virtually no spare blocks available which could be machined for use in the standard coaxial technique. Thus we have developed a strip-line test jig which permits testing material parameters on existing ferrite blocks without additional (destructive) machining. Special aspects, advantages and difficulties of this method are discussed. The bench measurements and also theoretical and numerical estimates of the beam coupling impedance of the kickers are under way.