Analyses of klystron modulator approaches for NLC
  Analyze of experimental results shows that the energy discharge efficiency of the modern modulators is 0.92-0.93. The energy transfer efficiency can be reached up to 0.7 for 1.5 usec pulse width and up to 0.8 for 3.0 usec accordingly. The geometry and core material of the transformer is one element of modulator, which limits the efficiency due to limitation if transmission band of the pulse power. Ways of the rise of energy transfer efficiency had been discussed. The use of features of coupled transmission lines lies in the base of an idea how the energy transfer efficiency can be improved up to 0.85 in the frame of the conventional approach. In the second part of the paper the transformerless modulator approaches are presented upon a modified Marx method of voltage multiplication using on/off IGBT instead of on switches. 
Anatoly Krasnykh