RESUMEN
High-temperature plasma irradiation of materials leads to significant modification of surface structure, growth of deposited composite films and surface layers with induced self-similar granularity on the scale from macroscales to nanoscale due to strong plasma-surface interaction. The aim of this study was to characterize lithium materials irradiated with high-temperature plasma in the T-10 tokamak and PLM device. The reactivity of lithium leads to reactions with impurities in the plasma and on the vessel. Post-mortem analyses by the X-ray photoemission spectroscopy and X-ray analysis have been used to identify deposits composition and morphology. Lithium carbonate composites have been detected by analysis demonstrating materials mixing and evidence of plasma-induced structure. New structures with the high specific surface area of hierarchical granular are registered. The reference industrial powder of lithium carbonate irradiated with steady-state plasma in the PLM device has acquired a new similar structure demonstrating universal influence of plasma on the structure of irradiated materials.
RESUMEN
The paper presents the latest results of the studies of small-scale fluctuations in a turbulent flow of solar wind (SW) using measurements with extremely high temporal resolution (up to 0.03 s) of the bright monitor of SW (BMSW) plasma spectrometer operating on astrophysical SPECTR-R spacecraft at distances up to 350,000 km from the Earth. The spectra of SW ion flux fluctuations in the range of scales between 0.03 and 100 s are systematically analysed. The difference of slopes in low- and high-frequency parts of spectra and the frequency of the break point between these two characteristic slopes was analysed for different conditions in the SW. The statistical properties of the SW ion flux fluctuations were thoroughly analysed on scales less than 10 s. A high level of intermittency is demonstrated. The extended self-similarity of SW ion flux turbulent flow is constantly observed. The approximation of non-Gaussian probability distribution function of ion flux fluctuations by the Tsallis statistics shows the non-extensive character of SW fluctuations. Statistical characteristics of ion flux fluctuations are compared with the predictions of a log-Poisson model. The log-Poisson parametrization of the structure function scaling has shown that well-defined filament-like plasma structures are, as a rule, observed in the turbulent SW flows.