Passage of radiation through a test hole

This paper discusses the passage of monoenergetic radiation through rectangular, cylindrical, and ring-shaped test holes. It is assumed that the sources are located at the far end and on the lateral surface of the test hole. Formulas are derived for calculating the radiation flux in test holes passing through both the shield and the core of the reactor. The results of the theory are compared with experiment.     

Regulation of the shape of the magnetic field's intensity in cyclotrons

The present article describes the experiments performed on a mock-up of the electromagnet of the 1.5-meter cyclotron at the I. V. Kurchatov Order of Lenin Institute of Atomic Energy, Academy of Sciences, USSR [1]. We investigated the optimum magnet geometry which would make it possible to maintain a constant shape of the magnetic field, the compensation of the magnetic field by means of circular windings which are placed in the operating gap between the caps, and also the action of sectorial windings, which serve for producing the first harmonic and for changing the magnetic field's variation depth. Experiments on the compensation of the magnetic field by means of circular windings, which were placed in the clearance for shimming, were organized. The compensation of a magnetic field with azimuthal variation was performed. The results of this investigation were used for selecting the compensating elements for a 1.5-meter cyclotron with azimuthal variation of the magnetic field's strength and controllable energy [2, 3].In conclusion, the authors extent their thanks to L. F. Kondrashev and V. K. Anokhin for their help in the work.     

THERMOELASTICITY OF A REGULARLY NONHOMOGENEOUS THIN CURVED LAYER WITH RAPIDLY VARYING THICKNESS

A regularly nonhomogeneous (composite), anisotropic, thin curved layer with rapidly oscillating material parameters and thickness is considered for the case when mean thickness and period scale have small magnitudes of the same order. A three-dimensional thermoelasticity problem for this layer is reduced to a homogenized shell model by means of an asymptotic homogenization method for periodic structures. The effective thermoelastic and thermal material parameters of this shell are expressed in terms of solutions for auxiliary local problems in the cell of periodicity. Using the solution of the boundary-value problem for the homogenized shell and the solutions of the local problems, one can obtain a three-dimensional microstructure of the stresses, displacements and temperature with a high accuracy

This general model is applied to the derivation of thermoelastic and thermal constitutive equations for network periodic shells. The relations obtained lay the foundation for a new continuous model of thermoelasticity and heat conductivity for network periodic shells and plates.