Laser decontamination device

Purpose: To avoid re-contamination of an object due to the deposition of removed materials. Constitution: Direction of laser beams transmitted in air or through a hollow cylinder is changed by 90deg by means of a reflection mirror and then the beams are guided to a head portion. A condenser lens is disposed in the head portion to focus the images at the surface of an object. An assist gas supply tube is in communication with the head portion for supplying assist gases for the protection of the lens and assisting melting. Further, a gas jetting nozzle for jetting a high speed gas stream is disposed on the side of the head portion, with the jetting axis being directed to the focused position on the object. Thus, the laser beams focused on the surface of the object cause crud layers to be melted and a portion of the crud layers is scattered by evaporization and the remaining portion is drawn off by the high speed gas stream. Accordingly, the crud layers can completely be removed with no recontamination. (Takahashi, M.)