Silver jewelry microanalysis with dual-pulse laser-induced breakdown spectroscopy: 266 + 1064  nm wavelength combination

Abstract

Orthogonal dual-wavelength dual-pulse laser-induced breakdown spectroscopy (ODWDP-LIBS) with 266+1064 nm wavelength combination was applied to realize silver jewelry microanalysis with enhanced sensitivity and minimal sample ablation. In this technique, the 266 nm laser with low pulse energy was selected as ablation laser and the time-delayed 1064 nm laser with moderate pulse energy was selected as reheating laser to enhance plasma emission. Significant signal enhancement was achieved under the excitation of the reheating laser without increasing mass ablation which was only determined by the ablation laser. Internal standard method was applied to realize quantitative analysis of copper impurity in silver jewelry samples. The calibration curve was built, and the limit of detection of copper in silver matrix was determined to be 37.4 ppm when the crater diameter was controlled at 6.5 μm. This technique is especially useful for microanalysis of precious samples due to the property of less sample ablation in comparison with single-pulse laser-induced breakdown spectroscopy (SP-LIBS) under the same analytical sensitivity.

Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

“…This ps laser pulses are employed to produce the fast electron from the laser ablated zircaloy target for further excitation of He by the fast electron bombardment. This two-laser arrangement is different from the conventional double pulse experiments [20][21][22][23][24][25][26][27][28][29][30] where the two lasers are employed for direct ablation and further excitation of the ablated atoms. Although the ps laser is employed to serve the specific role of producing fast electrons from the target, its irradiation on the target will inevitably generate emission from the ablated atoms and the He atoms in the ambient gas near the target surface.…”

Multi-element signal enhancement mechanism investigation for laser ablation-assisted ultraviolet laser excited atomic fluorescence

“…When the ablation energy increased, the crater grew larger and deeper, especially at 4.51 mJ. 33,34 In the LIBS scheme, sufficient laser energy needs to be applied to overcome the ablation and ionization thresholds. For a detectable signal, the energy is supposed to be higher than the detection threshold, as shown in Fig.…”

Investigation of the Surface Integrity of Q345 Steel After Nd:YAG Laser Cleaning of Oxidized Mining Parts

“…For the repetition rate (Figure 8b), when it was fixed to 8 kHz, an "edge accumulation" effect can be seen, that is, the laser beam acted on the surface of the corroded sample to form metal molten craters of a papillary shape, and in the edge of the craters existed a molten resolidified substance due to the pressure and liquid phase blast [18,19]. When the repetition rate was 10 kHz, as shown above, the effect of the surface cleaning was better.…”