Characterization of Boron-doped diamond and r-plane sapphire for plasma diagnostics in future nuclear fusion reactors -A survey of electrical and dielectric properties

p-Boron-doped polycrystalline CVD diamond samples were produced
and delivered by the German company Diamond Materials in Freiburg
(Germany). In a first step, main properties of this candidates for diagnostic
and/or heating windows in future nuclear fusion reactors were
investigated. By a special measurement technique, it was possible to
determine the Boron doping concentration in Diamond by measurement
of the resistive properties by using the van der Pauw method. So
prepared, an irradiation campaign with neutrons and/or heavy ions
on these samples will follow. The second material investigated, was
r-plane single crystalline sapphire. For the first characterization the
dielectric properties of a 3*-wafer in dependency of the frequency in
a FABRY-PEROT resonator setup was performed. Also, this is the
preparation for the next irradiation experiments in this project.