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We investigate a new modeling way for describing the continuous absorption of electromagnetic radiation in a dense partially ionized hydrogen plasma with electron densities 5·1018-1.5·1019 cm-3 and temperatures 16 000–25 000 K, in the wavelength range 300–500 nm. The results can be applied to the plasma of partially ionized layers of stellar atmospheres.

Nanostructured thin films on a silicon substrate were obtained by the action of high-frequency repetitively pulsed f ~ 10–13 kHz laser radiation with wavelength λ = 1.064 μm and power density q = 57 MW/cm2 on an La0.13Bi0.87FeO3 target at a pressure in the vacuum chamber p = 4.6 Pa. The morphology of the La0.13Bi0.87FeO3 thin films was studied using atomic force microscopy. Transmission spectra of the films in the visible and near- and mid-IR regions were obtained. The electrophysical characteristics of the La0.13Bi0.87FeO3 structures were analyzed. [ABSTRACT FROM AUTHOR]

The main aim of this work is to estimate the total contribution of the processes of molecular ion photodissociation and collisional absorption charge exchange to the opacity of DB white dwarf atmospheres, and compare this with the contribution of and other relevant radiative absorption processes included in standard models. The method for the calculations of the molecular ion photodissociation cross-sections is based on the dipole approximation and quantum-mechanical treatment of the internuclear motion, while the quasi-classical method for describing absorption processes in collisions is based on the quasi-static approximation. Absorption coefficients are calculated in the region and compared with the corresponding coefficients of other relevant absorption processes; the calculations of the optical depth of the atmosphere layers considered are performed in the far-UV and VUV regions; the contribution of the relevant absorption processes to the opacity of DB white dwarf atmospheres is examined. We examined the spectral ranges in which the total and absorption processes dominate in particular layers of DB white dwarf atmospheres. In addition, we show that in the region of the process of atom photoionization is also important, in spite of the fact that the ratio of hydrogen and helium abundances in the DB white dwarf atmosphere considered is . [ABSTRACT FROM AUTHOR]

The dynamic electric conductivity, dielectric permeability and refraction and reflection coefficients of a completely ionized gaseous plasma in a high frequency (HF) external electric field are calculated. These results are obtained within the self-consistent field approach developed earlier for the static conductivity determination. The plasma electron density, Ne, and temperature, T, varied within the following limits: 1019 ≤ Ne ≤ 1021 cm−3 and 2 × 104 ≤ T ≤ 106 K, respectively. The external electric field frequency, f, varied in the range 3 GHz≤ f ≤ 0.05ωp, where ωp is the circular plasma frequency. Thus, the upper limit for f is either in the microwave or in the far infrared frequency band. The final results are shown in a parameterized form, suitable for laboratory applications. [ABSTRACT FROM AUTHOR]