Surface oxide removal by a XeCl laser for decontamination

The laser ablation performed with an automated excimer XeCl laser unit is u sed for large surface cleaning. The study focuses on metal surfaces that ar e oxidised and are representative of contaminated surfaces with radionuclid es in a context of nuclear power plant maintenance. The unit contains an Xe Cl laser, the beam delivery system, the particle collection cell, and the s ystem for real-time control of cleaning processes. The interaction of laser radiation with a surface is considered, in particular, the surface damage caused by cleaning radiation. The beam delivery system consists of an optic al fibre bundle of 5 m long and allows delivering 150 W at 308 nm for laser surface cleaning. The cleaning process is controlled by analysing in real time the plasma electric field evolution. The system permits the cleaning o f 2 to 6 m(2) h(-1) of oxides with only slight substrate modifications.