Paint removal with a high repetition rate TEA CO/sub 2/ laser

Summary form only given. We are investigating the efficiency of paint removal with high average power (P/sub ac//spl ges/1 kW), high repetition rate (f/spl ges/1 kHz) TEA CO/sub 2/ lasers. Our lasers can deliver nearly 1 J per pulse with multiple transverse modes. Operation at 2000 Hz is possible, but not for long periods at present. At 1000 Hz, P/sub ac/=1 kW can be maintained for over 600 hours (>2/spl times/10/sup 9/ pulses) without major maintenance problems. We find that high repetition rates can lead to significant improvements in paint and primer removal efficiency. These results were obtained with samples representative of a commercial aircraft skin i.e. a 1 mm aluminium substrate covered with /spl ap/25 /spl mu/m of primer and as /spl ap/20 /spl mu/m topcoat of polyurethane paint. For convenience Gaussian beams were used with about 70% of the total pulse energy, E=0.3 J, in the initial gain spike of width 90 ns. The measured on-sample fluence was F(r)/spl ap/(2E//spl pi/w/sup 2/)exp(-2r/sup 2//w/sup 2/).