Download or read book Production et d sexcitation de noyaux chauds dans les r actions induites par des ions lourds d nergie comprise entre 10 et 84 MeV nucl on sur des cibles de masse moyenne written by Annick Lleres and published by . This book was released on 1988 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modes de production et de d sexcitation des noyaux chauds form s dans les r actions 84 kr 1 2 C 84 kr 27 Al 84 kr NaTi 26 4 34 4 et 45 4 MeV written by Béatrice Faure and published by . This book was released on 1988 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail est une contribution à l’étude des conditions de formation des noyaux chauds et de leurs modes de désexcitation aux énergies intermédiaires. Nous avons utilisé la cinématique inverse pour mesurer les caractéristiques inclusives des fragments de masse supérieure à 10 uma produits dans les réactions Kr + C, Al et Ti à 25, 35 et 45 MeV/u.L’analyse des spectres en vitesse et des distributions des fragments de masse inférieure à 40 uma (fragments complexes) met en évidence une composante d'émission par une source équilibrée, bien reproduite par un calcul de simulations Monte Carlo, sauf dans le cas des systèmes Kr + Al et Ti à 45,4.MeV/nucléon. De plus, une partie des évènements provient d'émission hors équilibre ou de processus dissipatifs. Pour les systèmes Kr + C à 25 et 35 MeV/u, la composante d'émission équilibrée correspond à la fusion complète, qui représente seulement un dixième de la section efficace des résidus d'évaporation. Dans les autres cas, le transfert d'impulsion est incomplet, mais reste supérieur à celui observé pour les résidus d'évaporation. L'émission de fragments complexes sélectionne donc les noyaux les plus chauds formés dans la réaction.Les vitesses de source associées aux résidus d'évaporation et aux fragments complexes diminuent lorsque le système devient plus symétrique et s'écartent alors des systématiques. Cette évolution n'est pas reproduite par le modèle de prééquilibre de Blann. Les vitesses de source et les masses moyennes des résidus d'évaporation sont compatibles avec l'expérience pour le système Kr + C, mais sont largement surestimées dans le cas de la cible de titane.Les énergies d'excitation maximales calculées dans l'hypothèse de transfert massif augmentent en fonction de l'énergie disponible et atteignent 5,8 MeV/u pour une énergie disponible égale à l'énergie de liaison.Pour un système donné, les sections efficaces de production des fragments complexes sont peu sensibles à l'énergie incidente, mais augmentent avec la masse de la cible. De plus, la production relative de résidus d'évaporation diminue par rapport à celle de fragments complexes lorsque l'énergie disponible augmente. Un modèle de désexcitation statistique incluant l'émission de fragments complexes reproduit qualitativement. Ces résultats en supposant un moment angulaire du noyau émetteur de 40 à 50h pour tous les systèmes. L'énergie d'excitation reste inférieure à 4,2 MeV/nucléon, c'est à-dire plus faible que dans l'hypothèse de transfert massif.
Download or read book FONCTIONS D EXCITATION ET PARCOURS MOYENS DES NOYAUX LOURDS PRODUITS DANS LES INTERACTIONS ENTRE LES IONS B ET LES CIBLES DE TA ET D AG written by F.. HUBERT and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ON UTILISE UN FAISCEAU D'IONS **(10)B ET **(11)B D'ENERGIE VOISINE DE 10,5 MEV/N. MESURE DES SECTIONS EFFICACES DES PRODUITS LOURDS FORMES DANS LA CIBLE. DANS LE CADRE DU NOYAU COMPOSE, ON MONTRE QUE LA THEORIE STATISTIQUE PERMET DE RENDRE COMPTE DES FONCTIONS D'EXCITATION EXPERIMENTALES SI L'ON TIENT COMPTE DE TOUTES LES POSSIBILITES DE DESEXCITATION DES NOYAUX
Download or read book ETUDE DE NOYAUX CHAUDS written by SYLVIE.. GROULT and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: LES NOYAUX CHAUDS PRODUITS DANS LA REACTION #4#0CA+#2#7AL SONT ETUDIES POUR DES ENERGIES INCIDENTES DE 25 ET 35 MEV/A. DANS UNE PREMIERE PARTIE, NOUS EXPOSONS LE CONTEXTE EXPERIMENTAL QUI NOUS A AMENES A REALISER CETTE EXPEIENCE ET A UTILISER LE MULTIDETECTEUR AMPHORA. L'EFFICACITE DE CE DERNIER POUR LES COLLISIONS LES PLUS VIOLENTES EST ENSUITE VERIFIEE. L'ETUDE DES NOYAUX CHAUDS NECESSITAIT LA DEFINITION D'UN CRITERE DE SELECTION DE COLLISIONS CENTRALES. NOUS AVONS ETABLI QU'UNE MULTIPLICITE DE PARTICULES LEGERES SUPERIEURE OU EGALE A 9 SELECTIONNAIT UNE CLASSE PARTICULIERE DE CES COLLISIONS CENTRALES. NOUS EXPOSONS LES RESULTATS EXPERIMENTAUX DEDUITS DE L'ETUDE DES NOYAUX CHAUDS AINSI SELECTIONNES: VITESSE DE LA SOURCE, ENERGIE D'EXCITATION, TEMPERATURE. APRES COMPARAISON AVEC UN CODE D'EVAPORATION, NOUS EN DEDUISONS DES ENERGIES D'EXCITATION PAR NUCLEON DE 6 MEV/A A 25 MEV/A ET 7.5 MEV/A A 35 MEV/A. MALGRE L'ACCROISSEMENT SIGNIFICATIF DES ENERGIES D'EXCITATION DES NOYAUX CHAUDS, NOUS N'OBSERVONS PAS DE BRUSQUE EVOLUTION SUR LES DISTRIBUTIONS DES CHARGES ET LES MULTIPLICITES DE FRAGMENTS LOURDS ASSOCIES. DES EVENEMENTS RARTES OU LES TROIS QUARTS DE LA CHARGE TOTALE SONT EMPORTES PAR LES PARTICULES LEGERES SONT ENSUITE ETUDIES. ILS SONT ASSOCIES A DES NOYAUX TRES CHAUDS ET NOUS LES QUALIFIONS D'EVENEMENTS DE VAPORISATION. LA COMPARAISON DES RESULTATS EXPERIMENTAUX ET DE CEUX D'UN CODE D'EVAPORATION STATISTIQUE CONFIRME QUE NOUS AVONS BIEN SELECTIONNE DES NOYAUX A TRES HAUTE ENERGIE D'EXCITATION. L'ACCORD EST EN GENERAL SATISFAISANT, SAUF EN CE QUI CONCERNE L'EVOLUTION DE LA DISTRIBUTION DES CHARGES EN FONCTION DE L'ENERGIE D'EXCITATION DE LA SOURCE. CES PROBLEMES NE DEVRAIENT CEPENDANT PAS REMETTRE EN CAUSE LA NATURE STATISTIQUE DES MECANISMES D'EVAPORATION
Download or read book PRODUCTION DE NOYAUX CHAUDS DANS LES REACTIONS AR AG A 50 ET 70 MEV U written by EMMANUEL.. VIENT and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: L'EXPERIENCE DECRITE DANS CE MEMOIRE A ETE ENTREPRISE AFIN D'ETUDIER LES NOYAUX CHAUDS PRODUITS DANS LES REACTIONS AR+AG A 50 ET 70 MEV/U, PLUS PARTICULIEREMENT CEUX QUI SE DESEXCITENT SUIVANT LA VOIE STANDARD DE DESEXCITATION: EVAPORATION DE PARTICULES LEGERES AVEC FORMATION D'UN RESIDU FROID EN VOIE DE SORTIE. LA DETECTION DES PARTICULES LEGERES CHARGEES EMISES EN COINCIDENCE AVEC UN RESIDU A IMPOSE DE CHOISIR UN DISPOSITIF EXPERIMENTAL EXCLUSIF ET UN DECLENCHEMENT AXE SUR LE RESIDU. ON A PU AINSI APRES AVOIR ISOLE LA CONTRIBUTION EVAPORATIVE PARMI LES PARTICULES LEGERES, RECONSTRUIRE LES CARACTERISTIQUES PHYSIQUES DU NOYAU CHAUD PRIMAIRE. IL RESSORT DE CETTE ETUDE DEUX FAITS IMPORTANTS: - UN NOYAU CHAUD PEUT SUPPORTER UNE ENERGIE D'EXCITATION DE 600 MEV ET UNE TEMPERATURE DE 8 MEV SANS SE DESAGREGER TOTALEMENT; - LES DISTRIBUTIONS D'ENERGIE D'EXCITATION DEPOSEE A 50 MEV/U ET 70 MEV/U SONT IDENTIQUES. LE DERNIER RESULTAT PEUT A PRIORI REFLETER, SOIT LE MECANISME DE DEPOT D'ENERGIE DURANT LA COLLISION, SOIT LES PROPRIETES INTRINSEQUES DES NOYAUX CHAUDS FORMES. DES DONNEES SUPPLEMENTAIRES PARTIELLES FOURNISSENT DES ARGUMENTS EN FAVEUR DE LA PREMIERE INTERPRETATION
Download or read book tude exp rimentale de l mission d ions secondaires partir de surfaces bombard es par des ions lourds d nergies par nucl on comprises entre O 1 et 5 MeV u written by Isabelle Lorthiois (auteur d'une thèse de sciences.) and published by . This book was released on 1983 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hypnosis written by Léon Chertok and published by Pergamon. This book was released on 1966 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Theory of Finite Systems written by Jean-Paul Blaizot and published by Mit Press. This book was released on 1986 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive and pedagogical account of the various methods used in the quantum theory of finite systems, including molecular, atomic, nuclear, and particle phenomena. Covering both background material and advanced topics and including nearly 200 problems, Quantum Theory of Finite Systems has been designed to serve primarily as a text and will also prove useful as a reference in research. The first of the book's four parts introduces the basic mathematical apparatus: second quantization, canonical transformations, Wick theorems and the resulting diagram expansions, and oscillator models. The second part presents mean field approximations and the recently developed path integral methods for the quantization of collective modes. Part three develops perturbation theory in terms of both time-dependent Feynman diagrams and time-independent Goldstone diagrams. A fourth part discusses variational methods based on correlated wavefunctions, including spin correlations. The approximation schemes are formulated for fermions and bosons at eigher zero or non-zero temperature. Although the formalism developed applies to both finite and infinite systems, the book stresses those aspects of the theory that are specific to the description of finite systems. Thus special attention is given to mean field approximations, the ensuing broken symmetries, and the associated collective motions such as rotations. Conversely, some specific features of systems with infinite numbers of degrees of freedom (such as the thermodynamic limit, critical phenomena, and the elimination of ultraviolet divergencies) are deliberately omitted. Jean-Paul Blaizot and Georges Ripka are associated with the Centre d'Etudes Nucleaires de Saclay.
Download or read book Proceedings of the Symposium written by United States. Navy Symposium on Military Oceanography and published by . This book was released on with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Reactor Physics written by Alain Hébert and published by Presses inter Polytechnique. This book was released on 2009 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Nuclear Data written by and published by . This book was released on 1957 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Industrial Application of Radioisotopes written by Gábor Földiák and published by . This book was released on 1986 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Introduction to Differential Manifolds written by Jacques Lafontaine and published by Springer. This book was released on 2015-07-29 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an introduction to differential manifolds. It gives solid preliminaries for more advanced topics: Riemannian manifolds, differential topology, Lie theory. It presupposes little background: the reader is only expected to master basic differential calculus, and a little point-set topology. The book covers the main topics of differential geometry: manifolds, tangent space, vector fields, differential forms, Lie groups, and a few more sophisticated topics such as de Rham cohomology, degree theory and the Gauss-Bonnet theorem for surfaces. Its ambition is to give solid foundations. In particular, the introduction of “abstract” notions such as manifolds or differential forms is motivated via questions and examples from mathematics or theoretical physics. More than 150 exercises, some of them easy and classical, some others more sophisticated, will help the beginner as well as the more expert reader. Solutions are provided for most of them. The book should be of interest to various readers: undergraduate and graduate students for a first contact to differential manifolds, mathematicians from other fields and physicists who wish to acquire some feeling about this beautiful theory. The original French text Introduction aux variétés différentielles has been a best-seller in its category in France for many years. Jacques Lafontaine was successively assistant Professor at Paris Diderot University and Professor at the University of Montpellier, where he is presently emeritus. His main research interests are Riemannian and pseudo-Riemannian geometry, including some aspects of mathematical relativity. Besides his personal research articles, he was involved in several textbooks and research monographs.
Download or read book Transport Theory written by James J. Duderstadt and published by John Wiley & Sons. This book was released on 1979 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: Problems after each chapter
Download or read book Aeronomy written by P. M. Banks and published by Elsevier. This book was released on 2013-09-24 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aeronomy, Part A is an attempt to make a comprehensive exposition of the processes in aeronomy, the study of composition, movement, and thermal balance of the upper regions of the planetary atmosphere. The text covers topics such as atmospheric regions and atmospheric density, the temperature and molecular mass of the atmosphere; the permanent constituents and the molecular and isotonic composition of the homosphere; and the transition from the homosphere to the heterosphere. Also covered are topics such as the temperature gradient and energies in the thermosphere, conditions at 200km and above 250km, solar radiation and ionization, and aeronomic reactions. The book is recommended for scientists, especially natural physicists, who would like to know more about the field of aeronomy and its advances.
Download or read book Nuclear Computational Science written by Yousry Azmy and published by Springer Science & Business Media. This book was released on 2010-04-15 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear engineering has undergone extensive progress over the years. In the past century, colossal developments have been made and with specific reference to the mathematical theory and computational science underlying this discipline, advances in areas such as high-order discretization methods, Krylov Methods and Iteration Acceleration have steadily grown. Nuclear Computational Science: A Century in Review addresses these topics and many more; topics which hold special ties to the first half of the century, and topics focused around the unique combination of nuclear engineering, computational science and mathematical theory. Comprising eight chapters, Nuclear Computational Science: A Century in Review incorporates a number of carefully selected issues representing a variety of problems, providing the reader with a wealth of information in both a clear and concise manner. The comprehensive nature of the coverage and the stature of the contributing authors combine to make this a unique landmark publication. Targeting the medium to advanced level academic, this book will appeal to researchers and students with an interest in the progression of mathematical theory and its application to nuclear computational science.
Download or read book The Physics of Nuclear Reactors written by Serge Marguet and published by Springer. This book was released on 2018-02-26 with total page 1462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive volume offers readers a progressive and highly detailed introduction to the complex behavior of neutrons in general, and in the context of nuclear power generation. A compendium and handbook for nuclear engineers, a source of teaching material for academic lecturers as well as a graduate text for advanced students and other non-experts wishing to enter this field, it is based on the author’s teaching and research experience and his recognized expertise in nuclear safety. After recapping a number of points in nuclear physics, placing the theoretical notions in their historical context, the book successively reveals the latest quantitative theories concerning: • The slowing-down of neutrons in matter • The charged particles and electromagnetic rays • The calculation scheme, especially the simplification hypothesis • The concept of criticality based on chain reactions • The theory of homogeneous and heterogeneous reactors • The problem of self-shielding • The theory of the nuclear reflector, a subject largely ignored in literature • The computational methods in transport and diffusion theories Complemented by more than 400 bibliographical references, some of which are commented and annotated, and augmented by an appendix on the history of reactor physics at EDF (Electricité De France), this book is the most comprehensive and up-to-date introduction to and reference resource in neutronics and reactor theory.
