Time-resolved electron temperature and density of spark discharge assisted femtosecond laser-induced breakdown spectroscopy

Abstract

In laser-induced breakdown spectroscopy (LIBS), spark-discharge (SP) is an effective auxiliary method to improve spectral emission intensity, and can effectively affect plasma temperature and electron density. In traditional LIBS technology, nanosecond laser is usually used as excitation source. Compared with nanosecond laser, femtosecond (fs) pulse laser has many advantages in the interaction between laser and matter. The SP can also enhance the emission intensity of fs-LIBS. However, the discussion on plasma temperature and electron density of SP assisted fs-LIBS is rare. In this study, we measured time-resolved spectra of fs-LIBS with the SP. By using the Boltzmann plot and the Stark broadening, we calculated time-resolved plasma temperatures and electron densities for different laser energies at different discharge voltages. We hope that this study can provide a better understanding for SP assisted fs-LIBS.