An x-ray radiator has a radiator housing from which x-ray radiation originating from a focus is emitted. The vacuum suction cup system is used for opening an envelope. With the aid of the measured electrical resistance, the proportion of crystals in the mixture can be kept constant within narrow margins. The method further includes applying metallic nanoparticles onto the binder layer to form a metallic nanoparticle layer on the binder layer. The active layer includes carbon nanotubes, and the gate dielectric film includes non-conjugated polymer containing an aromatic ring in a side chain.