• G. Busatto, C. Abbate, F. Iannuzzo, C.E. Pagliarone
  University of Cassino, Cassino
• F. Bedeschi, G.M. Piacentino
  INFN-Pisa, Pisa

The possible issues related to the use of last-generations Insulated Gate Bipolar Transistors (IGBTs) switches into a Marx-topology klystron modulator are discussed. Experimental results obtained from two cells Marx prototypes using two different solutions, including single device and series connected devices both hard-switched, are presented. The use of single high voltage device per cell allowed us to obtain lower on-state voltage drop but much slower switching times. On the other side the series connection of lower voltage IGBTs results in much faster commutations and lower devices costs accompanied by a larger on state voltage drop.