Spectral analysis of brass plasma generated by a Nd:YAQ laser at λ = 1064 nm

Abstract

The present study focuses on the mechanism by which the Nd: YAG laser energy affects the properties of plasma produced from locally manufactured copper and zinc alloys at the ratio of 80 to 20%. Five different laser energies (500–900 mJ) are used to study the apparent effects on the plasma at every energy value. The fundamental wavelength of the laser directed perpendicular to the alloy surface (target) is 1064 nm. Through the results obtained on the electron temperature and its density, it is shown that there is a clear and gradual increase in both of them with the increasing laser energy in addition to an increase in the intensity of spectral emissions at high energies. The electron temperature is calculated by the Boltzmann method, while the Stark expansion method is used to calculate the electron density. To deepen the understanding of the plasma behavior, the additional basic parameters are calculated, which include the plasma frequency (f_p), the Debye length (λ_D), and the number of charged particles in the Debye sphere (ND). The results show a clear increase in the plasma frequency and Debye length at high energies. On the other hand, there is a clear decrease in the Debye length when the laser energy increases. This study provides a deeper insight into the mechanisms of laser interaction with different materials, especially copper and zinc alloys, as it opens the way to improving many applications such as laser cutting and engraving using lasers, as well as spectral analysis of materials in the industrial field, in addition to many environmental and technological applications.