[en] We analyze the possibility to use gravitational lenses to diminish the Newtonian gravitational forces down to levels at which the effects of very weak bosons coupled to ordinary matter can be investigated by the method of spin echo using ultracold neutrons. (author)
Journal
[en] The ultracold neutrons are proposed to be used for the investigation of the gravitational field and as a tool to identify the gravitino 3/2, leading to an experimental control of the supergavitation theories. (author)
Journal
Revue Roumaine de Physique; ISSN 0035-4090; 
; v. 24(3-4); p. 243-247
; v. 24(3-4); p. 243-247
[en] The possibilities offered by the frequency characteristic method for the study of a subcritical assembly are compared with the possibilities offered by other methods. The preliminary experimental results obtained with a graphite and enriched-uranium assembly are interpreted in the light of Galanin's lattice theory. Nelkin's theory was used to interpret the neutron spectrum data obtained. (author)
[fr]
On compare les possibilités offertes par la méthode de la caractéristique de fréquence pour l'étude d'un ensemble sous-critique avec les possibilités offertes par d'autres méthodes. Les résultats expérimentaux préliminaires, obtenus par l'étude d'un réacteur à graphite et uranium enrichi, sont interprétés par la théorie des réseaux exposée par Galanine. On a étudié les informations que l’on peut obtenir sur le spectre de neutrons en utilisant la théorie de Nelkine. (author)[es]
Los autores comparan las posibilidades que presenta el método de la característica de frecuencia, para el estudio de un conjunto subcrítico, con las que ofrecen otros métodos. Con arreglo a la teorfa de los reticulados, expuesta por Galanin, interpretan los resultados experimentales preliminares, obtenidos mediante el estudio de un reactor de grafito y uranio enriquecido. Examinan las informaciones que sobre la base de la teoría de M. Nelkin pueden obtenerse acerca del espectro neutrónico. (author)[ru]
Sravnivajutsja vozmozhnosti, predostavljaemye metodom harakteristicheskoj chastoty dlja izuchenija podkriticheskoj sborki, s vozmozhnostjami, predostavljaemymi drugimi metodami. Predvaritel'nye jeksperimental'nye rezul'taty, poluchennye pri izuchenii grafitovogo reaktora s obogashhennym uranom, byli interpretirovany poi pomoshi razrabotannoj Galaninym teorii reshetok. Na osnove teorii Nel'kina izuchena informacija, poluchennaja na spektre nejtronov. (author)Source
International Atomic Energy Agency, Vienna (Austria); 494 p; Apr 1964; p. 71-86; Symposium on Exponential and Critical Experiments; Amsterdam (Netherlands); 2-6 Sep 1963; IAEA-SM--42/68; ISSN 0074-1884; ; 11 refs., 4 figs., 1 tab.
; 11 refs., 4 figs., 1 tab.
[en] Different conversion systems of the nuclear fission fragments energy in various electromagnetic energy forms are analyzed. Special attention is paid to the conversion in fission electric cells. A very simple theoretical model is used to describe the electron suppression by a grid with positive or negative potentials. The computations are compared with the experimental results obtained by the authors, in which voltages of several kV are produced. (author)
Journal
Studii si Cercetari de Fizica; ISSN 0039-3940; ; v. 30(3); p. 221-239
; v. 30(3); p. 221-239
[en] A few, but dramatized abnormal occurrences have haunted the nuclear debate on the issue of plant safety. While quality assurance and quality control mainly provide for failure-proof components and sub-assemblies, it is the man-designed and man-operated system of a nuclear power plant that makes a fool-proof achievement of safety particularly elusive. Sound ways and means of monitoring and of reacting properly to the behaviour of the highly complex, non-linear system of a nuclear power plant seems to be one of the keys to improving nuclear safety, thus giving rise to more confidence in the viability of nuclear power and less reluctance to its expansion. The paper hints at the possibility of working out integrative, automatic and low cost means of responding properly to the perturbation of a complex system. It bears on the design, licensing and, in particular, the operation of a nuclear power plant. The basis of the suggested solution stays within the existing mathematics of structural and dynamic stability, as well as within the possibilities of present-day communications services. The outcome might be a new approach to safety assurance and safety control complementary to present philosophies, and, as a practical result, a new monitoring device in the control room of a nuclear power plant. (author)
Source
International Atomic Energy Agency, Vienna (Austria); Proceedings series; 837 p; ISBN 92-0-050383-7; ; 1983; v. 4 p. 255-266; IAEA; Vienna; International conference on nuclear power experience; Vienna (Austria); 13-17 Sep 1982; IAEA-CN--42/139
; 1983; v. 4 p. 255-266; IAEA; Vienna; International conference on nuclear power experience; Vienna (Austria); 13-17 Sep 1982; IAEA-CN--42/139
[en] The paper reports on the transitory regimes that occur within the core of CANDU and WWER reactor regimes which might initiate boiling possibly resulting in local structural element failures. Neutron, thermal and hydraulic phenomena intermingle each other by feedback and can get out of control. The time variation of vapour bubble size and density as a major random phenomenon affects essentially the reactor stability. The study of this phenomenon have been performed on the basis of a statistical mathematical model. The analysis has revealed that the most critical situations occur directly after the initiation of the transient regimes and consequently the critical ranges of variations should be avoided. A greater temperature gradient inside the boundary layer is required in order to ensure the vapour bubble breaking. The mathematical model developed in this paper allows the study of the system behaviour for a large range of thermohydraulic and geometrical quantities. (authors). 16 figs., 7 refs
Journal