An Investigation of Enhanced Laser-Induced Spark Emission and Material Ablation Following Sequential Laser PulseExcitation

点击翻译按钮获取中文摘要

Professor Stanley Angel of the University of South Carolina is supported by the Analytical and Surface Chemistry program in a collaboration with Dr. A. DeGiacomo of the University of Bari, Italy. Through experiments and theory, the team is studying the mechanism of an atomic analytical method, laser-induced breakdown spectroscopy (LIBS), in order to improve LIBS as a technique capable of analyzing solids without sample preparation. Particularly, a dual pulse sequence has resulted in 100-fold enhanced LIBS, but the mechanism for the enhancement, larger plasma volume, lower continuum background and increased electron temperature are not known. Systematic studies will be conducted to test the hypothesis that the effects are due to plasma re-heating and pre-ionization above the sample. For example, the team will attempt to duplicate dual-pulse results by creating a pre-ionized region using glow discharge. Four elements, Al, Fe, Cu and Cr, in three sample matrices (glass, steel and pure metals) will be studied as model systems.Applications include environmental, health, forensic, geological and industrial analysis. The work will enable students to interact with international scientists as well as staff at the Lawrence Livermore National Laboratory.