Large-scale laser damage experiments on LIL mirrors: statistical analysis

A laser damage measurement campaign was realized on PHEBUS high power laser on two different high reflecting HfO2/SiO2 mirrors centered at the wavelength of 1.053 micrometers at 45 degrees incidence. The two tested mirrors were deposited using e-beam technology: a large 620 X 440 mm2 LIL mirror was made with an oxide HfO2 target, and a 100 mm-diameter mirror with a metal Hf target. The test were performed with a 40 mm wide beam. Damages were detected by light scattering on a separate facility. Macroscopic and microscopic images of the damages were taken. A statistical analysis of these data is proposed to compare the mirrors. It is also interesting to compare large beam damage data to small beam laboratory statistics.