Higher Technological Institute (HTI), 10th of Ramadan City, 6th of October Branch, Giza, Egypt.
National Institute of Laser Enhanced Sciences (NILES), Cairo University, Giza, Egypt.
Sci Rep. 2023 May 3;13(1):7218. doi: 10.1038/s41598-023-34227-3.
In the work that is being presented here, the effect of sample thickness and laser irradiance on the reduction of the signal-to-background ratio SBG and the plasma parameters, specifically electron temperature and electron density, is being investigated using back-reflection-enhanced laser-induced breakdown spectroscopy (BRELIBS). Copper and silver discs that had been highly polished were attached to the back surface of the glass target, and the Nd-YAG laser beam that was focused on the front surface of the target was tuned to its fundamental wavelength. The thicknesses of the transparent glass samples that were analysed were 1 mm, 3 mm, and 6 mm. One is able to achieve a range of different laser irradiance levels by adjusting the working distance that exists between the target sample and the focusing lens. The end result of this is that the signal-to-background ratio in the BRELIBS spectra of thicker glass samples is significantly lower as compared to the ratio in the spectra of thinner glass samples. In addition, a significant influence of modifying the laser irradiance (by increasing the working distance on the SBG ratio) is seen at various glass thicknesses for both BRELIBS and LIBS, with BRELIBS having a better SBG. Nevertheless, the laser-induced plasma parameter known as the electron temperature has not been significantly impacted by the decrease in the glass thickness.
在本次呈现的工作中，使用背反射增强激光诱导击穿光谱（BRELIBS）研究了样品厚度和激光辐照度对信号背景比（SBG）和等离子体参数（特别是电子温度和电子密度）降低的影响。将高度抛光的铜和银圆盘附着在玻璃靶材的背面，将聚焦在靶材正面的 Nd-YAG 激光调谐到其基频。分析用透明玻璃样品的厚度分别为 1mm、3mm 和 6mm。通过调节靶样品和聚焦透镜之间的工作距离，可以实现不同的激光辐照度水平。结果是，与较薄玻璃样品的光谱相比，较厚玻璃样品的 BRELIBS 光谱中的信号背景比明显降低。此外，在不同玻璃厚度下，通过增加工作距离（即改变激光辐照度）对 BRELIBS 和 LIBS 的 SBG 比均有显著影响，而 BRELIBS 的 SBG 更好。然而，玻璃厚度降低对激光诱导等离子体参数（即电子温度）没有明显影响。
