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P: Fachverband Plasmaphysik
P 14: Low Pressure Plasmas and their Application I
P 14.2: Talk
Wednesday, February 28, 2024, 11:30–11:45, WW 1: HS
Ro-vibrationally resolved corona modelling for the Fulcher-α band of H2 plasmas: a powerful tool for spectra analysis — •Richard C. Bergmayr1, Dirk Wünderlich1, Liam H. Scarlett2, Mark C. Zammit3, Igor Bray2, Dmitry V. Fursa2, and Ursel Fantz1 — 1IPP Garching, Germany — 2Curtin University, Australia — 3Los Alamos National Laboratory, USA
Collisional radiative (CR) modelling combined with emission spectroscopy enables the derivation of the plasma parameters (e.g. ne and Te) from the naturally emitted radiation of molecular hydrogen (H2) plasmas. Under certain conditions discussed in this contribution the simplified approach of corona modelling is valid, wherein collisional excitation from the ground state is balanced with spontaneous emission in the form of rate equations depending on reaction probabilities (e.g. cross sections) as input. The flexible Yacora code can solve the underlying system of equations coupling the manifold of ro-vibrational levels in H2. An electronically resolved CR model can determine for which plasma regimes the corona approximation must be extended by further process channels (e.g. cascades). This contribution discusses a corona model for the Fulcher-α band of H2 applying fully ro-vibrationally resolved MCCC cross sections. The MCCC (molecular convergent close-coupling) method in the adiabatic-nuclei formulation is an ab initio approach for electron scattering problems able to provide accurate ro-vibrationally resolved cross sections. The model derived spectra are compared with various benchmark cases demonstrating the model’s suitability as part of a non-invasive diagnostic.
Keywords: molecular hydrogen; emission spectroscopy; Fulcher band; population modelling; plasma physics