2020/02/21 by Roman Bergert, Slobodan Mitic, Bergert, Roman +3
Engineering · Physics and Astronomy · #Atomic Physics (physics.atom-ph) #Atomic and Molecular Physics #FOS: Physical sciences #Laser-induced spectroscopy and plasma #Plasma Diagnostics and Applications #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.2002.09218
openalex publication_date 2020/02/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Quantitative evaluation of tunable diode laser induced fluorescence (TDLIF)\nmeasurements in magnetized plasma take into account Zeeman splitting of\nenergetic levels and intra-multiplet mixing defining the density distribution\n(alignment) of excited \2p8 multiplet is discussed in this paper.\nTDLIF measurements were used to evaluate light-transport properties in a\nstrongly magnetized optically thick argon plasma under different pressure\nconditions. Therefore, a coupled system of rate balance equations were\nconstructed to describe laser pumping of individual magnetic sub-levels of\n\2p8 state through frequency separated sub-transitions originating\nfrom \1s4 magnetic sub-levels.\n The density distribution of \2p8 multiplet was described by\nbalancing laser pumping with losses including radiative decay, transfer of\nexcitation between the neighboring multiplets driven by neutral collisions and\nquenching due to electron and neutral collisions. Resulting \2p8\nmagnetic sub-level densities were then used to model polarization dependent\nfluorescence, consider self-absorption, which could be directly compared with\nmeasured polarization resolved TDLIF measurements. This enables to obtain\nunique solutions for the \1s4 and \1s5 magnetic sub-level\ndensities which were in good agreement with the densities obtained by laser\nabsorption measurements. It is shown that LIF measurements in magnetized plasma\nconditions have strong pressure dependence that should be corrected consider\neffective disalignment rate. The presented measurement method and model can\nhelp further understanding and improve description of optical emission of argon\nin magnetized conditions.\n