Determination of the absorption coefficient of solids in the short-wave region of the millimeter band

A technique for measuring the absorption coefficient of solids in the short-wave region of the millimeter band is described. The absorption coefficients of six materials were measured at a wavelength = 2mm.The authors express their gratitude for the interest of Academician A. M. Prokhorov, in whose laboratory this work was done. The authors also wish to thank E. A. Vinogradov for his assistance.     

Application of tomography method in millimeter wavelengths band II. Experimental

Tomographycal methods of image reconstruction of two-dimensional objects, surfaces or subsurface regions in millimeter wavelengths band are suggested and considered. Experimental images obtained using antennas and waveguiding lines of different types and radiation frequencyf≈33÷35GHz are represented. Volumetric dielectric objects and plane-parallel ferrite (or dielectric) plates distributed in free space or in homogeneous dielectric medium have been taken as objects under investigation. It is shown that in the frequency band under consideration, the images of investigated objects with characteristic dimensionA≈2λ÷7λ may be obtained by first-order diffraction tomography method (Born, Rytov or high frequency approximation of the first-order for electromagnetic field).     

Application of tomography method in millimeter wavelengths band I. Theoretical

Tomographic methods of image reconstruction of two-dimensional cross-sections of volumetric objects in millimeter wavelengths band are suggested and considered. It is shown that in the frequency band under consideration, the images of investigated objects may be obtained by first-order diffraction tomography method (Born, Rytov or high frequency approximation of the first-order for scattered electromagnetic field).     

Parameters of electronic detonation in solid dielectrics

Using KCl as an example, the electronic detonation parameters are studied in solid dielectrics at supersonic velocities of pulsed discharge channel propagation from the anode. The technique used to estimate the detonation parameters is based on theoretical approaches and experimental methods involved in the physics of detonation, explosion, and dense nonideal plasma.     

An NRD-fed dielectric rod antenna for the short millimeter wave band

A simple E-plane tapered rectangular dielectric rod fed by NRD guide is used as a millimeter wave antenna. This class of aerial features attractive radiation patterns with relatively low sidelobes and moderate gain. The measured results show that such an antenna and mounting structure can be exploited as effective radiating element in the short millimeter wave frequency band.     

Possibility of experimental determination of band structure parameters in many-valley semiconductors

We show possibility in principle to determine some parameters (density-of-states effective mass of different valleys, energy distances between valleys, energies of ionization of impurity levels split from different valleys) of the band structure in many-valley semiconductors, based on the experimental curve of temperature dependence of overall concentration of charge carriers.     

Flare angle changes antenna of the millimeter wave band

A pyramidal horn with flare-angle changes was designed at millimeter wave band with using of the S.Cohn's method of antenna pattern shaping. Results of the investigation show an assemblage of good properties are rest-ricted to this kind of antennas (if take into account such parameters as: form of beam, level of sidelobe and crosspolarization, microwave loss and radiation coefficient away from main lobe).     

One method for the self-consistent determination of instanton liquid parameters

The possibility of self-consistently determining instanton liquid parameters with optimal pseudoparticle configurations is discussed. The estimate of repulsive pseudoparticle-interaction weakening is obtained. A comparison of different ensembles of pseudoparticles is made.     

An NRD fed dielectric rod antenna for the short millimeter wave band

A simple E-plane tapered rectangular dielectric rod fed by NRD guide is used as a millimeter wave antenna. This class of aerial features attractive radiation patterns with relatively low sidelobes and moderate gain. The measured results show that such an antenna and mounting structure can be exploited as effective radiating element in the short millimeter wave frequency band.     

Creepage discharge along the surface of solid dielectrics in water

Experimental data is given for the discharge voltage for creepage discharge in tap water as a function of the thickness, flange length, (creepage path over dielectric surface), permittivity of the solid dielectric, field configuration, polarity of the applied voltage pulse, and a number of other parameters. The experimental data discussed are the delay time with dielectric flange sparkover by creepage discharge, the average discharge propagation rate for both polarities, and the creepage discharge current and leakage resistance.     

A method for the determination of lattice parameters on single crystals

The ratio method, designed originally for powder materials, is modified for single crystals. A relatively simple goniometer with photographic registration is used. Discussion of random and systematic errors shows that an accuracyΔa/a = 10^?4, or better, can be achieved. An application for single crystals of Fe and Fe-Si alloys is demonstrated. For pure iron the valuea= = (2·8664±00001)×10^?10 m is found.