LASER-DECONTAMINATION METHOD

摘要

PROBLEM TO BE SOLVED: To make it possible to obtain a smooth decontaminated surface which is affected by the recurrence of the agglomeration and adhesion of a contaminant, enables deeper decontamination and has high cleanliness by spatially controlling the formation of a projection around a part irradiated with a laser beam. SOLUTION: A contaminated surface layer is removed and cleaned through the continuous melting or evaporation of it by incorporating a condensing lens 32 into a gas-supplying nozzle 30 and supplying a gas and irradiating a contaminated member 14 with a laser beam 38 while relatively moving the lens 32 along the surface of the contaminated member 14. In this process, the gas is supplied asymmetrically to the axis 38a of the laser beam. For example, the gas is supplied diagonally to the axis of the laser beam by installing the gas- supplying nozzle 30 where the axis of the laser beam matches up to the axis 30a of the nozzle and an aperture 36 of the nozzle slants to the axis of the laser beams in such a direction as the axis of the nozzle can match up to the normal direction the contaminated member and the aperture of the nozzle can open forward in the moving direction of the nozzle to the surface of the contaminated member.