Comprehensive Analysis of Copper Plasma: A Laser-Induced Breakdown Spectroscopic Approach

Abstract

The emergence of diversified applications of laser-induced breakdown spectroscopy in the biomedical field, electronics, space physics, and material processing necessitates a comprehensive understanding of plasma parameters. The present work delineates the structure and evolution of copper plasma under different ambient pressures (0.01 mbar to 100 mbar) along with other plasma parameters. The study reveals the role of ambient pressure in the increase of plasma temperature (Te), electron density (Ne), number of particles in the Debye sphere, plasma frequency, inverse bremsstrahlung absorption coefficient, electron thermal velocity, electron–ion collision frequency and in the decrease of Debye length (λD) and plasma skin depth (PSD). The experimental techniques and the theoretical explanations for the variation of plasma parameters and their applications are also detailed. As the ambient pressure increases, the motion of plasma species becomes restricted, resulting in the increase of Te, calculated using the Boltzmann plot. From the values of λD, PSD, and Ne, it is understood that the copper plasma under investigation is thermally non-relativistic and satisfies McWhirter’s criterion, thus, revealing the local thermodynamic equilibrium condition of plasma. The effects of Debye shielding and stark broadening on the spectral lines are also investigated. Thus, the study helps bring newfangled dimensions to the application of plasma by exploring the possibility of tailoring plasma parameters.

Keywords

• LIBS
• laser-induced plasma
• plasma parameters
• copper plasma