激光诱导击穿光谱技术是一种近年来随着激光技术和光谱检测技术的发展而兴起的物质成分检测技术。该技术具有快速、无损、操作简单、无需样品处理等诸多优点，而传统LIBS检测方法存在谱线强度弱、信噪比低等缺点，直接影响定量分析精度。为了增强激光诱导击穿光谱发射强度，提高信噪比，设计了高度为1 mm，直径分别为2 、3、4 、5 、6 mm；直径为5 mm，高度为1 、2 、3、4、5、6 mm的不同腔体，应用粒径分别为10、20、30 nm的纳米金颗粒与腔体结合对样品等离子体进行作用。实验表明，最优腔体直径为5 mm，高度为4 mm；最优纳米金粒径为20 nm。相比传统LIBS，在最优腔体、最优纳米金和最优腔体与最优纳米金联合作用下，增强因子分别为20.6、7.3、31.3，柱形腔体可以提高等离子体电子温度，纳米金粒子对电子温度几乎没有影响。纳米金粒子与柱形腔体均能提高光谱信号信噪比，在最优腔体和最优纳米金联合作用下，信噪比最高。

Laser-induced breakdown spectroscopy (LIBS) is a material composition detection technology that has emerged in recent years with the development of laser technology and spectral detection technology. This technology has many advantages such as fast, non-destructive, simple operation, and no sample pretreatment , but the traditional LIBS has the shortcomings of weak spectral intensity and low SNR, which directly affects the accuracy of quantitative analysis.To enhance the laser-induced breakdown spectrum intensity and improve the SNR, some different cavities were designed (height of 1 mm, diameters of 2, 3, 4 , 5, 6 mm; Diameter of 5 mm, heights of 1, 2, 3, 4, 5, 6 mm), the Au-NPs (Au nanoparticles) (diameter of 10, 20, 30 nm) was combined with the cavity to confine the plasma spectrum of the sample. Experiments show that the optimal cavity diameter is 5 mm and the height is 4 mm, the optimal Au-NPs size is 20 nm. Compared with the traditional LIBS, under the optimal cavity, Au-NPs and the combined action of the optimal cavity with Au-NPs, the enhancement factors are 20.6, 7.3, and 31.3, respectively. The cavity can increase the plasma electron temperature and Au-NPs have almost no effect on the electron temperature. Both the Au-NPs and cavity can improve the SNR. Under the combined action of the optimal cavity and the optical Au-NPs, the SNR is the highest.