[en] The system used in the institute is described and intended for providing reactor computations with multigroup macroconstants on the basis of catalogs of 26- group microconstants having subgroup presentation of resonance cross sections structure and presentation by the means of self-shielding factors. The system includes complexes of computer programs for homogenization of constants by means of averaging of cross sections of heterogeneous lattice cell in different approximations. This method and combination of the constants bloc with programs for two and one-dimensional reactors computation gives possibility of correct computation of heterogeneous fast critical assemblies which in turn is necessary for utilisation of experimental results obtained for checking and correction the constants system used. (author)

[en] The inner integral over final particle energy or collision cosine of the multigroup transfer matrix is evaluated analytically for the general nonrelativistic two-body interaction. Under the condition that the center-of-mass angular distribution is piecewise linear, the solution is exact. Refs

[en] To obtain the library of group constants derived from the estimated nuclear data the programs system FEDGROUP was developed. This system is flexible enough to obtain any group constants library derived from any source of estimated data. The FEDGROUP system is open one which means that it can be connected to any system of constants maintenance and any algorithm of group constants calculation can be added. Teh system is written on FORTRAN and intended for BESM-6 and CDC-3300 computers. (I.T.)

[en] With computers becoming more frequently used in theoretical and experimental physics, physicists can no longer afford to be ignorant of the basic techniques and results of computer science. Computing principles belong in a physicist's tool box, along with experimental methods and applied mathematics, and the easiest way to educate physicists in computing is to provide, as part of the undergraduate curriculum, a computing course designed specifically for physicists. As well, the working physicist should interact with computer scientists, giving them challenging problems in return for their expertise. (orig.)

No abstract available

[en] The listing of computer programs available in Swierk is given. There are brief descriptions of potentialities of these programs. The plan of works for creation of the algorithms of heightened accuracy for transport equations solution is given. The problem of the finite elements methods application for solution of this equation is investigated in more details. (auth.)

No abstract available

[en] The progress of computer algebra observed during these last years has had certainly an impact in physics. I want to precise the role of these new techniques in this application domain and to analyze their present limitations. In Section 1, I describe briefly the use of algebraic manipulation programs at the elementary level. The numerical and symbolic solutions of problems are compared in Section 2. Section 3 is devoted to a prospective about the use of computer algebra at the highest level, as an ''intelligent'' system. I recall in Section 4 what is required from a system to be used in physics

[en] The necessity of check computations of physical characteristics of fast reactors using different computer programs developed in different institutions and using simple models (test variants) is shown. The results of comparison of some computations (criticality, critical mass) for some variants of reactors by different computer programs of one and two-dimensional calculation by different calculation methods and approximations are given. The computations results comparison is done by means of constant system BNAB. (author)

[en] Investigation on the case of equations which, like the sine-Gordon and Korteweg de Vries equations, have localized solutions, but for which the interaction of solitons results in both a transfer of momentum and in a change in the internal structure of the interacting solitons is given. The final state consists only of solitons, or of both solitons and waves. The Korteweg de Vries equation arises as an approximation in a variety of physical contexts including plasma physics, the theory of water waves and the properties of coupled non linear oscillators. The sine-Gordon equation arises as an approximation in the theory of the Josephson effect, the study of self-induced transparency, and other phenomena. Equations of the type studied arise from the sine-Gordon equation when higher order terms are taken into account (equations of motion of a self-interacting, scalar, charged classical field, and equations of motion of an electric field in certain semi-conductors. The results obtained on the non-linear, charged, Klein Gordon (NLKG) equation by means of numerical integration are discussed and an interpretation of the results is presented