Plasma freddo

The proposed technology offers a novel and versatile method for detecting cracks in insulating materials of electrically polarized metal devices, i.e. dielectric coatings on metals, especially in low-pressure gas environments. It uses an ionized plasma that interacts uniformly with the insulating surface, allowing to detect defects invisible to the naked eye. The detection occurs in a single test without changing the environmental conditions and without risking harmful electrical discharges.

The technology refers to an innovative plasma (ionized gas) source operating at atmospheric pressure and low electric power levels. A cold plasma is produced, characterized by an ion temperature significantly lower than the electron temperature. Partial ionization of a Helium flux is induced by a time-varying electric field in between two parallel grids, both perpendicular to the flux itself.