TM0, 1.5, 0 mode cavity for longitudinal bunch feedback kicker

TM0, 1.5, 0 mode cavity has been proposed for a longitudinal kicker of wide band bunch feedback system in B-factory. This is a kind of parallel-plate radial-line power combiner, in its center beams are accelerated or decelerated on axial electric field. In order to improve the power efficiency, the gap width around the beam is made wider than the outer part, as a result the shunt impedance becomes as high as 1.1 kΩ. Because of its simple axial-symmetric structure, we can use well established theory of accelerating cavity and also analyze the HOM problems with minimum ambiguity. There is no floating electrode inside vacuum, it is easy to fabricate and attach cooling water loops