Gold Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy Technology under Low Pressure

It has become a trend to realize charged detection of vacuum switch vacuum degree based on laser-induced breakdown spectroscopy technology. However, due to its high detection limit and low sensitivity, it is easily interfered by background noise, resulting in low accuracy. A large number of studies have shown that metal nanoparticles can effectively enhance signal detection capabilities, but their enhancement effect under low pressure is not yet clear. This study uses nanoparticle laser-induced breakdown spectroscopy technology to optimize the vacuum charge detection accuracy of vacuum switches, and explores the enhancement effect of gold nanoparticles on spectral signals in a low-pressure environment. The research results show that under the standard air pressure of vacuum switch operation, gold nanoparticles have a significant enhancement effect on the spectral signal, and the enhancement effect is affected by particle size and concentration, each showing different rules, and there is an optimal solution. In addition, gold nanoparticles with larger particle sizes under low pressure have a longer residence time in the unexpanded state when the plasma is first excited, which leads to different changing trends in the plasma radiation intensity integral, thereby increasing the vacuum degree and charging detection accuracy.