Plasma Formation And Its Sustainment In Time And Space In Microwave Enhanced Laser Induced Breakdown Spectroscopy
Y. Ikeda (1), J. K. Soriano (1), N. Kawahara (2)
(1) i-Lab., Inc. KIBC 213 5-5-2 Minatojima-Minami, Chuo, Kobe, 650-0047 Japan
(2) Department of Mechanical Engineering, Okayama University, Tsushima-Naka 3, Okayama 700-8530, Japan
The transient and unstable plasma generation in the laser-induced breakdown is potentially resolved by the addition of microwaves. The laser and microwave technology combination extends the plasma lifetime and enhanced its emission intensity and volume. The expansion of the plasma started a few seconds after the initial formation of the plasma seed and the absorption of the microwave by the plasma also started to take effect. Large dome-shaped plasma is then briefly sustained until the end of the microwave duration. As the plasma expands, the plasma drifts away from the sample surface which is a good indication of the non-ablation effect of the microwave energy. The expansion of the plasma by microwaves enhances the breakdown of the plasma but potentially regulates the formation of toxic ablation fumes.