Experimental results are presented on the generation and dynamics of concentric as well as non-concentric multiple double layers in hot filament type discharge plasma. These results emphasize striking similarities between the generation and dynamics of both types of multiple double layers, i.e. similar potential steps corresponding to the ionization energy in used gas, similar hysteresis cycles in the current-voltage characteristic of the exciting electrode, similar dynamic behaviour, etc. The results show that a common physical mechanism is at the origin of both phenomena, in which electron-neutral impact excitation and ionization reactions play a key role.
Periodic current bursts observed in the dynamic current-voltage characteristic of a probe in the presence of a plasma fireball in dynamic state were modeled in the frame of the scale relativity model, based on both the fractal space-time concept and the generalization of Einstein’s principle of relativity to scale transformations. The bursts appear in the probe characteristic when a certain relation exists between the fireball dynamics frequency and the frequency of the probe voltage sweep. The double layer dynamics is described by a set of time-dependent Schrödinger-type equations and the self-structuring is given by means of the negative differential resistance. The obtained experimental and theoretical results are proven to be in very good agreement.
The results obtained both in quantum chemical computation and in solvatochromic study of pyridinium di-carbethoxy methylid (PCCM) are correlated in order to estimate the electric dipole moment in the excited state of this molecule. This estimation is made by a variational method in the hypothesis that the molecular polarizability does not change in time of the absorption process. Ternary solutions of PCCM in protic binary solvents are used here, both establishing the contribution of each type of interaction to the spectral shift and to characterize the composition of the first solvation shell of PCCM. Results are compared with those obtained before for other binary solvents. The difference between the interaction energies in molecular pairs of PCCM-active solvent and PCCM-less active solvent was also estimated based on the cell statistical model of the ternary solutions.
Anodic double layer instabilities occur in low-temperature diffusion filament-type discharge plasma by applying a certain positive bias with respect to the plasma potential to an additional electrode. Periodic nonlinear regimes, characterized by proper dynamics of double layers, are sustained if excitation and ionization rates in front of the electrode reach the value for which current limitation effects appear in the static current-voltage characteristic. It was experimentally shown that under specific experimental conditions these ordered spatiotemporal phenomena can evolve into chaotic states by type I intermittency. This transition was verified by the evolution of time series, fast Fourier transform amplitude plots, three–dimensional reconstructed state spaces, power laws, and flickering phenomena spectrum, as well as by the return map and tangent bifurcation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.