Design of the modulator for the CTF3 tail clipper kicker

The goal of the present CLIC Test Facility (CTF3) is to demonstrate the technical feasibility of specific key issues in the CLIC scheme. The extracted beam from the combiner ring (CR), of 35 A in magnitude and 140 ns duration, is sent to the new CLic EXperimental area (CLEX) facility. A tail clipper (TC) is required, in the CR to CLEX transfer line, to allow the duration of the extracted beam pulse to be adjusted. It is proposed to use a stripline kicker for the TC, with each of the deflector plates driven to equal but opposite potential. The TC kick must have a fast rise-time, of not more than 5 ns, in order to minimize uncontrolled beam loss. Several different options are being investigated to meet the demanding specifications for the modulator of the TC. This paper discusses options considered for the fast, high voltage, semiconductor switches and shows results of initial tests on the switches.