The absorption of γ-radiation in infinite lattice systems

The distributions of absorbed -radiation energy between the sources forming an infinite lattice and the ambient medium are compared. The distributions were calculated by the Monte-Carlo method in a Strela electronic computer and by an age approximation. Calculations were made for several values of the initial -radiation energies and parts by volume (volumetric fractions) V of the source material and for the irradiated medium of two specific systems. In one of these a n indium-gallium liquid alloy was used as the source, the heat-conducting elements of an IRT reactor serving as the source in the other. In both cases, the irradiated medium was water. From the results obtained, conclusions are drawn with regard to the limits of applicability of age approximation in calculations of the distribution of absorbed -radiation energy in such systems.Translated from Atomnaya Énergiya, Vol. 13, No. 12, pp. 568–571, December, 1962     

Transmission of scattered γ-radiation in water

Measurements have been made of the attenuation of doses of scattered-photons from Au¹⁹⁸, Co⁶⁰, and Na²⁴ sources as a function of the distance between the source and the detector for various collimation angles, thereby eliminating the possibility of primary-radiation from entering the detector. The measurements were carried out at distances ranging from 3 to 4 and 8 to 12 mean-free-paths for the-photons. The collimation angles were varied from 30 to 80. The experimental data which were obtained are compared with the results of calculations based on an assumption which allows the problem to be reduced to the calculation of a triple integral rather than the direct solution of the kinetic equation. Satisfactory agreement is found between the experimental and theoretical results.In conclusion the authors wish to express their gratitude to Dr. Phys.-Math. Sciences A. K. Krasin for setting up the problem and for illuminating discussions on the results of the measurements, to Dr. Phys.-Math, Sciences G. I. Marchuk for a number of remarks concerned with the calculation and also to V. A. Tolstikov for participating in the present series of experiments.     

The distribution of ionization along a beam of γ-radiation and the determination of radiation dose with normal ionization chambers

It was established that the ionization effect, measured in normal ionization chambers for determining the dose in a region of -radiation, must be referred to a point in space, displaced by a distance of about from the center of the measuring electrode of the chamber towards the source. The corrections for displacement of the measuring volume for the -radiation of Cs¹³⁷ and Co⁶⁰, respectively, equal 0.996 and 0.992.     

Identification tables for use in the analysis of α and β activities

In order to facilitate the identification of activities being subjected to analysis, tables are compiled according to data published prior to 1958 containing the distribution of all known - and -radioactive isotopes as a function of their T_1/2, end-point energies of their -spectra, and -particle energies. The tables make it possible to establish a group of isotopes with a previously established T_1/2 and energies of radioactive emission. In a number of cases, the use of a scheme involving the radioactive decay chain may also prove expedient in the identification of activities.We consider it our duty to express our gratitude to Yu. A. Zysin for a discussion and his advice.     

The action of α-radiation on aqueous acid solutions

We investigated the action of polonium -radiation on a 0.8 N aqueous solution of sulfuric acid.It was established that over a wide range of dissolved polonium concentrations (0.1–12 mC/ml), the initial radiation-chemical hydrogen peroxide yield remains the same and equals 1.20 molecules per 100 ev of absorbed energy and that the hydrogen peroxide concentration tends toward a limit. The equilibrium limit of hydrogen peroxide concentration in 0.8 N sulfuric acid is 5–8·10¹⁸ molecules/ml.     

Experimental and computational determination of the dose characteristics of a standard source of γ-radiation

The absorbed dose in a calorimeter is compared with Monte Carlo calculations for a standard source of exposure dose of γ-radiation from ⁶⁰Co. It is shown that if the initial γ-radiation spectrum is known to a high degree of accuracy, then a mathematical model of the interaction of particles and γ-rays with matter can be used to calculate the absorbed dose in a detector and the exposure dose in air to within several percent. This makes it possible to develop an experimental-computational method of transferring the dimensional units for the exposure dose and dose rate from a static standard to working means of measurement and pulsed bremsstrahlung sources.