[en] QAS is a module that performs multidimensional point-kernel estimation of gamma transport through practically any type of shielding material via a simplified input scheme that follows the general input philosophy of the SCALE shielding sequences SAS1, SAS2, and SAS4. This paper presents a general overview of the theory and input requirements for QADS

[en] Methods of computerized solution of the problem of 10-100 keV energy electron passage through matter are developed. This may form the basis of theoretical description of rather complex physical phenomena involving participation of such electrons. Validity of accepted approach to solution of the problem and correctness of used physical formulas and numerical factors are verified by comparison of test calculations with experimental results described in publications. 35 refs.; 6 figs

[en] The ionization loss of the fast heavy charged particles in matter is discussed. More exact formula for the cross section of energy loss is suggested. Statistical properties of the distribution of ionization loss in thin and very thin layers of matter allow to calculate the distribution function and to model corresponding random number with large accuracy and a very small expenditure of computer time. The results of calculations correspond to experimental data. 12 refs., 2 figs., 1 tab

[en] CEPXS/ONELD is the only discrete ordinates code capable of modelling the fully-coupled electron-photon cascade at high energies. Quantities that are related to the particle flux such as dose and charge deposition can readily be obtained. This deterministic code is much faster than comparable Monte Carlo codes. The unique adjoint transport capability of CEPXS/ONELD also enables response functions to be readily calculated. Version 2.0 of the CEPXS/ONELD code package has been designed to allow users who are not expert in discrete ordinates methods to fully exploit the code's capabilities. 14 refs., 15 figs

[en] If a fermion is travelling through a medium, it can have matter-induced magnetic and electric dipole moments. These contributions conserve chirality, and can be nonvanishing even for a Majorana neutrino. Several implications for neutrino physics are discussed

[en] The flow of neutral particles which interact with a background material but not with themselves is described in some generality by a linear kinetic, or transport, equation. This equation, while algebraically complex, has a very simple physical content; it is simply the mathematical statement of particle conservation in phase space. Applications of such transport descriptions are numerous. They include neutron migration in nuclear reactors, radiative transfer (thermal photon flow), neutrino flow in astrophysical problems, neutral particle transport in plasmas, gamma ray transport in shielding considerations, and Knudsen flow arising in the kinetic theory of gases. A vast literature exists on the formulation and solution methods, both analytical and numerical, of such transport problems, but generally only in the nonstochastic area. The author uses the terms stochastic and nonstochastic throughout this article in a special sense. That is, particle transport is in itself a stochastic process, but this is not the stochasticity or lack thereof that is meant when the terms open-quotes stochastic transportclose quotes and open-quotes nonstochastic transportclose quotes are used. In this use of the word, nonstochastic means that the properties, as functions of space and time, of the background material with which the particles interact are either specified or can conceptually be computed in a deterministic fashion

[en] In the EGS4 code, too small or large step sizes violate the limits of the electron multiple scattering theory used. The limits are stricter with decreasing the electron energy so that the relation of the step size and the multiple scattering theory in the low energy region was examined with PRESTA. Energy deposition in water irradiated by electron beams of 30 to 200 keV was calculated. The parameters chosen to change the step sizes were the geometric mesh width, ESTEPE, and AE. Too small mesh width and ESTEPE turned off the multiple scattering simulation, which resulted in widely different curves from those with the full simulation of the multiple scattering. For large AE, the energy deposition obtained became zero at the shallower depth than the electron range since the energy straggling for the electrons of the energy below 2AE is not considered in the EGS4. (author)

[en] In the course of providing numerical benchmarks to the nuclear and medical industries, it is desirable to continually obtain solutions that use the available computational facilities to the greatest possible extent. Analytical benchmarks are generally simple problems, yet they provide numerical results that are numerically accurate to a desired error. Greater accuracy can be obtained at the expense of computational time. The simplest types of problems are usually those that evaluate the scalar flux, and the simplest geometry is an infinite homogeneous medium. However, depending on the source configuration, the scalar flux in an infinite medium can have spatial variation in one, two, or three dimensions. This paper shows how a three-dimensional problem can be generated by considering two-dimensional finite disk and rectangular sources

[en] In this work, data of charge profiles in thin slabs were obtained. The thickness from 0.0004 to 0.006 g/cm² of the slabs consisting of material with atomic number between 4 and 79 irradiated by 5 MeV electrons is considered. These data were obtained by means of the special worked out code for computation of charge caused by secondary electrons. In this code a new method which we had called method of trajectory translation is used. A charge distribution dependencies on energy of primary electron, atomic number of slabs and also its thickness were discussed. Conclusions concerning those dependencies, and some recommendations for choice of codes parameters mere provided

[en] By using the characteristic X-ray sources and the Si(Li) detector system, the X-ray mass attenuation coefficients for Si, Fe, Cu, Y, In, Sn and SiH₄ have been systematically measured in the energy range of 1.486∼29.109 keV. The accuracy of experimental data has been reduced to +-1%