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Vol 45, No 5 (2018)
- Year: 2018
- Articles: 7
- URL: https://journals.rcsi.science/1068-3356/issue/view/14128
Article
Kinetics of Low-Temperature Microphotoluminescence of Exciton-Impurity Complexes in CdZnTe Single Crystals
Abstract
Low-temperature (6.5 K) microphotoluminescence near the intrinsic absorption edge of CdZnTe alloy single crystals is studied under conditions of non-resonant and resonant excitation by picosecond pulses. Characteristic relaxation times for free excitons and exciton-impurity complexes of various types are determined. A significant (by a factor of 4–8) decrease in the photoluminescence signal decay time of exciton-impurity complexes on neutral donors during the transition to the resonant excitation mode is detected. The detected sharp decrease in the photoluminescence signal decay time can indicate the manifestation of collective effects in this system of emitters.
131-135
Streamer Rest Mass and its Limit Velocity
Abstract
Based on the nonlinear plasma-waveguide model of the electrical breakdown of gases, experiments on neutron generation in electric discharge processes are considered. An analysis of these processes makes it possible to determine the lower limit of the streamer mass as 10−23 g and the existence of the upper limit of the streamer propagation at the level of 109 cm/s.
136-140
Microwave Photonic Crystal from Spirals
Abstract
Features of microwave propagation through a two-dimensional periodic structure of cylindrical spiral coils were studied in the frequency range from 8.5 to 12 GHz. The frequency dependence of the effective refractive index nef of the structure is measured. The features of measurements are noted and the structure reflectance is estimated in various regions of the frequency range under study. In the frequency range where nef ~ 0, a surface wave propagating around the structure is detected.
141-144
Type 1a Supernova Explosion and the Origin of Sugar Chiral Asymmetry in Biological Systems
Abstract
It was shown that circularly polarized ultraviolet from positrons generated during the decay of radioactive cobalt 56Co produced by the type 1a Supernova explosion in the space scenario of the prebiological stage of the origin of life with regard to the appearance of the chiral asymmetry seed of sugars and their precursors is the most powerful astrophysical source of chiral influence. Arguments in favor of the fact that the role of sugars (ribose) in the origin of life is more important in comparison with amino acids are presented. The properties of nuclear forces uniquely determine the sign of the biosphere chiral asymmetry, observed on the Earth: left amino acids and right sugars strongly dominate (chiral purity).
145-148
Estimation of Rate Constants of Thermal Dissociation of Two-Atomic Compounds and Three-Particle Association in the Temperatures Range from 500 to 5000 K
Abstract
Based on an analysis of the approximation dependences on the dissociation energy for rate constants of thermal dissociation of two-atomic compounds and three-particle association, constructed by the least-squares method, an analytical expression for their estimation is derived. It is shown that the calculated and approximation dependences of the published data almost coincide with each other. The maximum disagreement of the dependences does not exceed 2% for the temperature range from 500 to 5000 K.
149-152
Study of an Experimental Prototype of the DTeT Detector in the Proton Beam of a Radiotherapeutic Accelerator
Abstract
An experimental prototype of the television-type detector is developed, fabricated, and tested; its calibration capability is verified at the “Prometheus” proton accelerator; two-coordinate measurements of the energy release region in a water phantom are performed. The energy release region sizes are experimentally determined in the form of Bragg curves during pulsed irradiation of the water phantom with a proton beam with an energy from 65 to 192.5 MeV.
153-158
On the Problem of the Electromagnetic Field Energy in a Medium with Temporal and Spatial Dispersion under Absorption Conditions
Abstract
The problem of calculating the electromagnetic field energy outside the transmission band is discussed. It is shown that the contribution of charged particles to the electromagnetic perturbation energy can be described in the general case in terms of the bilinear combination of the medium dielectric polarizability. An explicit form of such a contribution is found. The relations obtained are used to generalize Planck’s law to the case of an absorbing medium.
159-164