Wavelet-based analysis of lower hybrid full-wave fields

In this paper, we introduce the use of Continuous-Wavelet-Transform (CWT) to postprocess full-wave fields of Lower Hybrid (LH) waves which have been generated using the LHEAF code. Compared to the Fourier transform, the CWT has the appealing property of yielding information as to the spatial location of spectral modes. Using a complex-Morlet CWT, the complicated full-wave field pattern is decomposed into its spectral components parallel to the static magnetic field n||. In general, the CWT of the LHEAF full-wave fields shows that the local wave spectrum broadens as the waves propagate through the plasma and after reflection off the low density cutoff or the vacuum vessel walls. The goal of this analysis is to provide a tool to assess the importance of full-wave effects on the transformation of the wave n|| spectrum which governs the LH power absorption and driven currents.