Laser ablation plasma expansion using microwaves

This study explores the potential of utilizing microwaves to sustain the expansion of transient laser ablation plasma of Zr target. By application of microwaves on the plasma, we observe a significant enhancement with a two to three order of magnitude increase in the plasma emission intensity, and 18 times increase in the plasma’s spatial volume. We investigate the temperature change of the plasma and observe that it decreases from 10,000 K to approximately 3000 K. Electron temperature decreased with volume expansion owing to increased surrounding air interaction, while the plasma can be sustained in air using microwaves. The increase in electron temperature during temperature drop is indicative of non-equilibrium plasma. Our results emphasize the contribution of microwaves in promoting enhanced emission and plasma formation at controlled, low temperature, thereby demonstrating the potential of microwaves to enhance the accuracy and performance of laser-induced breakdown spectroscopy. Importantly, our study suggests that microwaves could also mitigate the generation of toxic fumes and dust during ablation, a critical benefit when handling hazardous materials. The system we've developed is highly valuable for a range of applications, notably including the potential to reduce the possible emergence of toxic fumes during the decommissioning of nuclear debris.