Application of Noise Radiation to Determine the Refractive Index of a Substance in the Gaseous Phase and in the Condensed State in the Range of 2–4 GHz

Continuous spectrum radiation in the frequency range of 2–4 GHz is generated by a plasma relativistic source. The pulsed radiation is fed into a rectangular waveguide measuring 72 × 34 mm2 with the substance under study. A piston is inserted into the waveguide, and the refractive index of the substance is determined by the appearance of the interference pattern. The substance in the waveguide can be a gas or have the form of a rectangular bar or a cuvette with liquid. It can be used for spectroscopy of dielectrics.