[en] The report on hand includes the experiments on criticality published from 1975 till 1980. About 90 experiments with the most important related data are listed. They are capable of being called up, with the data base system KRITEXP, by 14 different descriptors or printed in any arrangement or order. This is the basis for a global or purposeful verification of the calculating method for criticality safety. The proof of reliability of the calculations for the criticality analysis are immediately relevant for the licencing procedure under atomic law for all plants of the nuclear fuel cycle where nuclear fuels are handled. Since no criticality experiments are being carried out in the Federal Republic of Germany, the data collection on hand will help to fill this gap with regard to the assessment of experiments carried out in other countries. (orig.)

[en] This paper presents the results of an analysis of both published and unpublished critical current data given as a function of both field and temperature. Simple formulas have been obtained for (1) the critical temperature as a function of field that is needed to obtain an estimate of the current sharing temperature and hence temperature margin, (2) the critical current density for constant temperature as a function of field, and (3) the critical current density for constant field as a function of temperature

[en] Critical data for homogenous U(NAT)O₂-PuO₂-H₂O-systems with PuO₂ parts of 35 and 45 wt.% PuO₂ of the total oxide were drawn up, whereby the plutonium was present as 100 wt.% ²³⁹Pu. In the case of the 45 wt.% PuO₂ fraction Pu was also present as a mixture of 95 wt.% ²³⁹Pu and 5 wt.% ²⁴⁰Pu. All systems had a water reflector of 30 cm thickness (total reflection). Calculations were carried out using the spectral programme GAMTEC (16 energy groups, P₁ approximation) and with the transport code PTF-IV in S₈ order. Experiments were verified by calculations to support the cross-sections used. The discrepancy between the experimental and calculated values was +-1%. (orig.)

[en] The indicated numerical values and curves refer to an isolated system of uranylnitrate (UO₂(NO₃)₂) (100% uranium 235) homogenously distributed in light water (H₂O) with maximum reflection by light water. Maximum reflection is obtained by an at least 30 cm thick water layer with a density of 1 g/cm³. (orig.)

[en] Nuclear criticality safety practices used at the Feed Materials Production Center at Fernald, Ohio in conjunction with its metal dissolving and nonmetal, e.g., ash and ore concentrates, digesting operations are reviewed. Operating procedures with several different types of dissolver or digestor systems, i.e., metal dissolver, continuous, drum and safe geometry, are discussed. Calculations performed to verify the criticality safety of the operations are described

[en] This thesis is divided into two sections, each dealing with the response of a superconducting proximity system to an applied magnetic field. In Section I, the maximum supercurrent that can be carried in an applied perpendicular magnetic field by a superconducting normal-metal superconducting (SNS) junction consisting of a square normal-metal layer sandwiched between two crossed perpendicular superconducting strips is investigated theoretically. For weak applied fields, the critical current is suppressed reversibly as induced Meissner screening currents flow into the SNS sandwich and generate a spatially varying magnetic field largely parallel to the junction, thereby altering the local phase difference. For stronger applied fields, the critical current is changed irreversibly as vortices enter and become pinned in the junction. In Section II, Eilenberger's quasi-classical formulation of superconductivity is used to derive an equation for the upper critical field of a multilayered SN system in a perpendicular magnetic field. The alternating layers are coupled via the proximity effect and are in the dirty limit

[en] The authors have fabricated Mo /SUB x/ C /SUB 1-x/ thin film samples by sputtering, and have studied the dependence of superconducting critical temperatures, fields, and currents on composition and microstructure. For x in the range from 40-60%, the preferred nonequilibrium Mo-C B1 phase (with T /SUB c/ up to 13K) grows in an oriented columnar structure, with column diameters of 100-1000A. This is correlated with sharply enhanced perpendicular critical fields (with extrapolated values of H /SUB c2/ (0) that can exceed 300k0e) together with a critical current density that may be as large as 10⁶ A/cm². They also present data on artificial layered structures based on Mo-C, fabricated either by alternately sputtering Si layers or by pulsed gas injection of N₂

[en] Measurements have been made of the critical magnetic field of superconducting granular aluminum (dapprox.30 A) down to temperatures well below T/sub c/(t²<0.1). The results show that it is possible to have the coupling between grains weak enough and the temperature low enough so that the critical field is that of the isolated grain while at the same time the large fluctuations which exist in isolated grains of this size are suppressed. The results for T/sub c/, together with those from other sources, indicate that the maximum T/sub c/ is a function of grain size only

[en] In reviewing the literature published between 1969 and 1979 about superconducting materials the monograph stresses the connection between superconducting parameters on the one hand and the crystal structure, position of the superconductor-forming elements in the periodic table, chemical composition and phases, grain structure as well as preparation and treatment conditions on the other hand. The subject is covered under the following headings: fundamentals of superconductivity and superconducting materials, preparation of superconducting materials, preparation of superconducting layers by physical and electrochemical methods, possibilities of increasing the critical parameters, and applications of superconducting materials. 179 figures, 81 tables, and 958 references are included

[en] Vortex structure is considered in a superconducting corrugated film placed in an external magnetic field close to the upper critical one (Hsub(c2)). Cinzburg-Landau free energy is obtained in case of the vortex lattice and corrugation commensurability. An increase of the upper critical field is found under the above conditions. Critical currents are calculated taking into account the commensurability edge effect