Effect of sample temperature on time-resolved laser-induced breakdown spectroscopy

Abstract

Increasing sample temperature is an effective method for improving emission intensity of laser-induced breakdown spectroscopy (LIBS). An increase in the sample temperature requires only simple modification to LIBS system, and does not require sample pretreatment. In addition, the formation and decay of laser-induced plasma (LIP) are a dynamic physical process. Time-resolved spectroscopy can enrich the dynamic information of LIBS and increase data dimension. The further analysis of the time-resolved LIBS data has the potential to understand the physical process. In this study, a beam of nanosecond laser was used to excite brass sample to produce plasma. The time-resolved spectroscopy of the LIP was measured at different sample temperatures. The results indicated that increasing sample temperature improved optical emission intensity in LIBS, and increased the plasma persistence. We also obtained plasma temperature and electron density at different sample temperatures. The time-resolved plasma temperature and electron density in the case with higher sample temperature were higher than those in the case with lower sample temperature. Moreover, the decay of electron density at higher sample temperature was faster than that at lower sample temperature.