Decontamination Characteristics of 304 Stainless Steel Surfaces by a Q-switched Nd:YAG Laser at 532 nm

Metal surface decontamination characteristics were investigated by using a laser ablation method. A second harmonic generation of a Q-switched Nd:YAG laser with a wave length of 532 nm, a pulse energy of 150 mJ and a pulse width of 5 ns was employed to assess the decontamination performance for metal surfaces contaminated with CsNO3, Co(NH4)2(SO4)2, Eu2O3 and CeO2. The ablation behavior was investigated for the decontamination variables such as a number of laser shots, laser fluence and an irradiation angle. Their optimum values were found to be 8, 13.3 J/cm2 and 30 .deg., respectively. The decontamination efficiency was different depending on the kinds of the contaminated ions, due to their different melting and boiling points and was in the order: CsNO3>Co(NH4)2(SO4)2>Eu2O3>CeO2. We also evaluated a correlation between the metal ablation thickness and the number of laser shots for the different laser fluences