Prospects of Development of Radiation Technologies in Russia

The present review article describes the role of radiation technologies in various realms of human activities, including fundamental science, industry, agriculture, and medicine. The development of radiation technologies in the world and in Russia is compared. The total number of ionizing-radiation sources in the world is approximately 11 million units, most of them being radioactive sources (about six to seven million units) and x-ray facilities (about four million units). The number of high-technology facilities (such as accelerators and tomography units of various types) that employ ionizing radiation does not exceed 200 thousand units. In Russia, there are more than 153 thousand units of such instruments and facilities. They include about 64700 units employing x-ray radiation; about 79700 radioisotope devices and setups, reactors, and radioactive-waste storage facilities; and 471 accelerators. The most promising lines of development of radiation technologies in Russia are analyzed from the strategic and economic points of view.

     

Semi-classical approximation and the problem of boundary conditions in the theory of relativistic particle radiation

Abstract

The process of relativistic particle radiation in an external field has been studied in the semi-classical approximation rather extensively. The main problem arising in the studies is to express the formula of the quantum theory of radiation in terms of classical quantities, for example of the classical trajectories. However, it still remains unclear how the particle trajectory is assigned, that is which particular initial or boundary conditions determine the trajectory in semi-classical approximation quantum theory of radiation.

We shall try to solve this problem. Its importance comes from the fact that in some cases one and the same boundary conditions may give rise to two or more trajectories. We demonstrate that this fact must necessarily be taken into account on deriving the classical limit for the formulae of the quantum theory of radiation, since it leads to a specific interference effect in radiation.

The method we used to deal with the problem is similar to the method employed by Fock to analyze the problem of a canonical transformation in classical and quantum mechanics.     

Third annual ALS users’ meeting

The 20^th anniversary of Synchrotron Radiation News is a good opportunity to think back about the extraordinary development of the field during that period. From personal experience I can offer comments in two areas: ? the evolution of synchrotron radiation research facilities from the 1970s to the 1990s;

? the early history and impact of wiggler and undulator insertion devices.

     

Grating-Outcoupled Radiation in Second-Order Fiber Bragg Gratings

Abstract

The experimental results of the radiation for second-order fiber Bragg gratings, which are made of a single-mode photosensitive fiber (PS-1500; Fiber-Core Corp.) and a single-mode fiber (SMF-28; Corning Inc.), by a phase mask writing fabrication technique are explored. For PS-1500 fiber Bragg gratings, the maximum radiation efficiency of ?23.5 dB at resonance λ = 1,539.34 nm with a very narrow bandwidth (about 0.02 nm) are measured from a 10-mm-diameter photo-detector, while for SMF-28 fiber Bragg gratings, the maximum radiation efficiency is ?34.6 dB (λ = 1,538.03 nm) with a bandwidth of 0.06 nm. The total efficiencies of the radiation are about ?16.8 dB for PS-1500 fiber Bragg gratings and ?28.1 dB for SMF-28 fiber Bragg gratings.     

Über die Jeanssche Zahl und die Wärmestrahlung in anisotropen und absorbierenden Körpern

Jeans' number gives the number of vibration modes of electromagnetic equilibrium radiation. By application ofJeans' original method, a formula for this quantity is derived, valid for an anisotropic and dispersive medium. This derivation is followed by a discussion of different points of view of equilibrium radiation as built up by elementary beams. Finally, for an absorbing uniaxial crystal in thermal equilibrium, a relationship is derived, giving the number of quantum transitions related to emission and absorption of light.     

光谱辐照度测量的数学模型及其方法研究

光谱辐照度是光谱辐射计量中最基本的参数，是研究各种辐射源及光电探测器特性的重要依据。为提高光谱辐照度的测量精度和量值溯源等问题，国防科工委光学计量一级站采用BB3200K高温黑体作为基准的辐射源，以新型辐射测温法为基础，通过一系列光辐射理论和几何原理推导出辐射温度与辐射光功率之间的关系；通过对光辐射功率的绝对测量，并结合低温辐射计，从而完成了光谱辐照度量值的精度测量。该理论奠基了以探测器为基础的新的光辐射量传体系。主要介绍了在光谱辐照度标准装置的项目中复现光谱辐照度所建立的数学模型及新的测试方法，给出了测量结果，并简要介绍了基于该理论的测量装置的组成及原理。     

Analysis of Phototherapy Effectiveness Using Thermography

A thermographic study of low-intensity phototherapeutic effects on the human body in situ was carried out. The feature of the work was the measurement of the dynamics of surface temperature changes in a bio-object for 40 min after the cessation of irradiation. The relaxation character of the temperature behavior with quasi-oscillating phenomena during the selected observation period has been established. An explanation of the observed phenomena with the involvement of literature data is proposed. It is shown that 15-min irradiation at a radiation intensity of 14mWcm^?2 is optimal for phototherapy at a wavelength of 640 nm. A conclusion was made about the possibility of considering changes in the local temperature of a bio-object as a correlated parameter to determine the optimal dose of radiation during phototherapy.

     

Beiträge zur Isotopengeochemie von Erdgasen

It is the proper aim of geochemical investigations regarding natural gas to describe the processes of generation, migration and accumulation of gaseous compounds. By this way our research results should contribute to knowledge about the gas generating potential of organic matter and about the expected gas volumes in natural gas deposits.

The main topics in the authors' research project are

- isotopic characterization of hydrocarbon forming organic matter

- simulation of the generation of natural gas components by coalification processes (model experiments including also radiolytic gas formation from organic matter)

- investigation of various separation processes (diffusion, adsorption, solubility, mixing of gases. oxidation of natural gas components) affecting chemical compositions and isotopic signatures

- elucidation of pressure and temperature dependence of separation processes and especially of the elementary isotope separation cofficients in systems gas/sorbent

- as the main result, an interpretation concept for natural gas samples is proposed which is based on chemical and isotopic compositions of methane and ethane in the samples and which takes into consideration also separation processes.

Following this summarizing publication some of the most important results of our research work will be presented in more detail in three separate parts.     

A model with superconducting solution in quantum field theory

By considering a theory based on a simple model the mathematical possibilities are analysed when the same energy operator may have in quantum theory two (approximatively) orthogonal ground states and eigenfunction systems. The consequences for the elementary particle physics are discussed.

     

Process Analytical Chemistry: Applications of Ultraviolet/Visible Spectrometry in Environmental Analysis: An Overview

Abstract

Process analyzers based on the selective absorption of the ultraviolet (UV) and/or visible (VIS) radiation provide an on-line monitoring highly reliable of the composition and the industrial process control.

This review provides information about the technological advances in this area and its industrial applications, especially environmental applications.     

Large volume high pressure research using the wiggler port at NSLS

Abstract

A DIA-type cubic-anvil high pressure apparatus (SAM-85) has been interfaced with white x-ray radiation from the superconducting wiggler port of the National Synchrotron Light Source at Brookhaven National Laboratory. Energy-dispersive x-ray diffraction measurements can be obtained for samples with dimensions of the order of 1 mm as a function of pressure and temperature utilizing x-ray energies of up to100 keV.

The sample environment is examined. Pressure is uniform in the sample chamber to within 0.1 GPa, and temperature is constant in the scattering volume to within 5°C.A method is defined for determining deviatoric stress. We find that for a sample containing NaCl and Au, the deviatoric stress increases to about 0.3 GPa as pressure increases to 1.5 GPa and then remains constant, probably reflecting the strength of the sample. Upon heating, the deviatoric stress quickly approaches zero.

Presented at the IUCr Workshop on ‘Synchrotron Radiation Instrumentation for High Pressure Crystallography’, Daresbury Laboratory 20-21 July 1991     

The effect of gamma radiation on the stator insulation of rotating electrical machines

ABSTRACT

The paper examines the influence of γ radiation on the stability of the insulation characteristics of the stator winding of rotating electrical machines. The tested insulation characteristics are loss tangent angle, resistance, polarization factor, threshold voltage of partial discharge, breakdown voltage, coefficient of proportionality and lifetime exponent. The radiation dose was used as the γ radiation parameter. Different winding areas have been specifically tested in which a different impact is expected on technological winding production process. Tests were performed on a representative statistical sample under well-controlled laboratory conditions. The combined measurement uncertainty of the experimental procedure was about 5%.     

NMR Experiments on Ion Permeation in Irradiated Model Membranes

In aqueous solutions of sonicated egg-lecithin vesicles (5 weight-%) the ¹H-NMR parameters line width, area, and chemical shift of the signal of the (CH₃)₃N⁺ group were determined in dependence on the dose of gamma radiation (0 … 12 kGy). The application of curopium ions made it possible, by means of a line shape analysis, to calculate these parameters for the inside as well as for the outside lipid layer.

With increasing ⁶⁰Co-radiation dose the line widths increase linearly. The line width for the outside lipid layer increases significantly more rapidly than for the inside layer. This fact allows us to conclude that there exists a preferred radiation damage of the outside lipid layer. The asymmetry may he a consequence of an indirect radiation action mediated by the radicals of the water radiolysis.

From the temporal change of the NMR parameters information can be obtained about the radiation action on transport processes in the vesicles. Beginning at a threshold value (approx. 5 kGy) the permeation of the En^{+ ++} ions to the (CH₃)₃N⁺ head groups previously not accessible increases significantly.     

Macroscopic Quantum Superposition in Opto-Mechanical System with Ultrastrong Coupling Light-Matter Interaction

In this paper we propose an efficient method for creating macroscopically distinct mechanical superposition states in an ultra strongly-coupled light-matter system. By modulating the opto-mechanical coupling sinusoidally, the radiation pressure can be turned into a built-in resonant driving force effectively. Thus the mechanical displacement can be significantly amplified.

     

Calculation of line width in channeling radiation by optical potential method

Abstract

The line width problem in channeling radiation is considered in terms of the optical potential method. It is shown that the plasmon excitations do not contribute to the line width.     

Obituary

Abstract

The gamma irradiation damage in silicon has been extensively studied by many investigators.^(1–6) However, little has been reported about the effects of radiation on the current-voltage (I–V) characteristics of silicon, particularly of high-resistivity silicon at radiation temperatures other than the room temperature. This paper is a report of some new results on the I–V characteristics of low and high resistivity silicon before and after gamma irradiation at the temperature of 38 °C and ?196 °C.     

The Concept of an Erosion Monitor for In-Vessel ITER Components with the Use of a Pulsed Laser

The erosion monitor is the ITER diagnostic system designed to control the erosion and deposition of materials on the plasma-facing components of the vacuum vessel under the influence of particle flows and radiation from the plasma. The required accuracy and range of measurements can be achieved using the two-frequency speckle interferometry method. However, because of vibration of the installation, the images should be taken in such a short time that is not provided by existing CMOS cameras. In this paper, it is proposed to use an interferometer based on a pulsed solid-state laser with a tunable radiation wavelength, and methods for recording interferograms under vibration conditions are considered. The required laser parameters are estimated; the expected results are analyzed.

     

Optische Eigenschaften der Festkörper

An elementary discussion of the effects of light interacting with matter, in particular solids, is presented. Both linear and nonlinear effects are considered with a more explicit discussion of the linear effects. The three classical mechanisms for this interaction in crystalline solids, interaction with lattice vibrations, interband electronic interaction, and intraband electronic interaction are discussed at an elementary level which requires minimal use of quantum mechanics. Magnetooptical effects and transitions observed in the very far UV with synchrotron radiation also form part of the discussion.

     

Fundamental and technological aspects of glass studied by nuclear techniques

Abstract

Nuclear techniques (Rutherford back-scattering and nuclear reactions) appear very useful in the near surface analysis of glass. These techniques offer a non-destructive method of analysis, with high depth resolution without radiation effects induced by the ion beam.

In this paper we present some experimental results concerning the analysis of glass surfaces obtained by different treatments. Initially the water vapour attack kinetics was investigated with the ²³Na(ρ, α)²⁰Ne nuclear reaction. Measurements were performed on three different flat glasses obtained by different industrial processes.

Another aspect of particular importance from both scientific and applied viewpoints is the kinetics of the surface reaction and diffusion processes occurring in silicate glasses. In particular the Na⁺?K⁺ interdiffusion has been investigated with the RBS technique at different temperatures in aluminosilicate and borosilicate glasses.

Finally, a technological aspect of great interest is connected to the optical properties modification when glasses are covered with different types of coatings. RBS analysis allows helpful information about elemental composition of the coatings and their depth distribution. In many cases it is possible to obtain the stoichiometric composition and the thickness when atomic density is known.     

Formation of the 255-keV annihilation line near the magnetic poles of pulsars

The possibility of existance is discussed for pulsars emitting soft γ radiation near their magnetic poles upon the annihilation of ultrarelativistic positrons from the magnetosphere and electrons from the surface of a star. With an increase in the energy of incident positrons, the photon energy of this backward radiation tends to a constant value m _e c ²/2=255 keV. This radiation is shown to be directed opposite to the positron flux direction.