Energy Of Optical Radiation Research Articles

Corona discharge in a nuclear excited dusty plasma

A nuclear excited dusty plasma can be used effec� tively in systems of direct nuclear energy conversion, for example, into optical radiation energy. However, to compensate for gravity and to confine charged dust particles, a potential trap must be formed in a nuclear excited plasma. High pressures (1–100 atm) are needed to effectively use a nuclear excited plasma. Here, we investigate the possibility of using a corona electric discharge to provide the existence of dust structures before the action of hard radiation on a plasma–dust medium. The problem is considered in terms of continuum equations. We consider the case where a nuclear excited dusty plasma is in a cylinder of length L and radius R (L/R 1) with a wire of radius r 0 stretched through the center. The distributions of the number densities of electrons (ne), singly charged atomic (ni) and molecular (nmi) ions, excited atoms (n*), and metastable atoms (nam) and molecules (nMm) depend on the specific kinetics of elementary processes and the local electric field Er(r). These stationary distribu� tions can be found by simultaneously solving the par� ticle number balance equations,

Modeling of optical radiation energy distribution in plant tissue

A three-dimensional mathematical model of interactions of optical radiation with plant tissue taking into account its structural inhomogeneity, spectral properties, and the effects of fluorescence is constructed. The developed model is implemented using the statistical Monte Carlo method for the Henyey-Greenstein phase function. The dependence of differential backscattering and fluorescence coefficients on the concentration of photosynthetic pigments (chlorophylls) is numerically studied. It is demonstrated that numerical characteristics agree with results of physical experiment. The approximate solution based on the expansion of the diffusion and fluorescence radiation fluxes into a series in terms of a small parameter is found. This expansion makes it possible to calculate the field of backscattered radiation with satisfactory accuracy and to qualitatively correctly describe the experimentally observed dependences of the fluorescence coefficient in the region of high chlorophyll concentration.

Method of calibrating pulse photometers of radiation energy and power with conversion in time

Based on methods developed earlier for calibrating the sensitivity of pulse photometers, a new modification of the method is proposed for attenuating pulsed radiation energy in wide limits, reaching a factor of 106, without using optical attenuators. Calibration errors over high and low reference levels of optical-radiation energy and power are considered.

On the theory of nonradiative transitions in optical excitation of gaseous media

A new approach and a theoretical model for describing experimentally observed nonradiative effects are considered. Nonradiative transitions in an ensemble of polyatomic molecules are interpreted as conversion of absorbed energy of optical radiation to energy of thermal translational motion of gas molecules. The model includes explicit account for intermolecular interactions. The form of the corresponding model Hamiltonian in the approximation of pairwise interactions of molecules and methods for its calculation are proposed. It is shown that all required matrix elements of the theory are easy to calculate, and the method is suitable for both qualitative and quantitative analysis of nonradiative effects.

Highly efficient difference-frequency generation in the field of frequency-modulated optical radiation

It is shown for the first time that when optical radiation, which is frequency- or phase-modulated by microwave oscillations, propagates through a quadratically nonlinear medium in a high-Q microwave cavity, the optical radiation energy can be converted very efficiently into the energy of a microwave of frequency equal to the modulation frequency.

Nonlinear absorption of optical radiation energy by microparticles in a transparent dielectric

Nonlinear absorption of energy and thermal processes during interaction of optical radiation pulses with microparticles in a transparent dielectric are theoretically studied, taking into account temperature dependence of the thermal and optical parameters.