A linear accelerator having cast dielectric composite layers integrally
formed with conductor electrodes in a solventless fabrication process,
with the cast dielectric composite preferably having a nanoparticle
filler in an organic polymer such as a thermosetting resin. By
incorporating this cast dielectric composite the dielectric constant of
critical insulating layers of the transmission lines of the accelerator
are increased while simultaneously maintaining high dielectric strengths
for the accelerator.