Power spectral fractalysis: a surrogate method for laser-induced plasma temperature analysis

Abstract

The paper deciphers the potential of fractal analysis in unveiling the complex plasma dynamics. The light from copper plasma is focused on the slit of a spectrometer, and the spectral variations across the slit are analysed. The plasma temperature (T) computed from the spectrum at various spatial points of the slit also exhibits a variation similar to that of power spectral fractal dimension ($D_{\text {p}})$. The study reveals a strong correlation between T and $D_{\text {p}}$, reflecting the complex dynamics and the compositional anisotropy in plasma. At the plasma core, where the temperature is the highest, and the matter is in the ionised state, the $D_{\text {p}}$ is high, and the lower temperature regions show a lower $D_{\text {p}}$ value. The fractalysis helps analyse plasma temperature without knowing transition probability and the energy of the upper-level corresponding to each value of wavelength. Thus, the power spectral fractalysis can be considered a surrogate method for understanding the plasma temperature and the particle dynamics involved.