Download or read book CONTRIBUTION A L ETUDE DES EFFETS DE L IRRADIATION ALPHA SUR LES VERRES NUCLEAIRES written by ABDALKARIM.. ABBAS and published by . This book was released on 2001 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'OBJET DE CETTE ETUDE A ETE DE CARACTERISER LES EFFETS DE L'IRRADIATION ALPHA SUR LES VERRES NUCLEAIRES. NOUS AVONS SUIVI UNE DOUBLE APPROCHE, PAR L'EXPERIENCE ET PAR LA SIMULATION NUMERIQUE. LA STRUCTURE DU VERRE NUCLEAIRE FRANCAIS, R7T7, A ETE SIMULEE EN UTILISANT DES VERRES A 4 ET 6 OXYDES CONTENANT LES PRINCIPAUX ELEMENTS DE CE VERRE : SIO 2, B 2O 3, NA 2O, ZRO 2, AL 2O 3 ET CAO. CES VERRES ONT ETE IRRADIES AUX IONS HE + DE 1 MEV (PROCESSUS ELECTRONIQUES) ET KR 3 + DE 2,1 MEV (PROCESSUS ELECTRONIQUES ET BALISTIQUES), CE QUI NOUS A PERMIS DE REPRODUIRE A LA FOIS LES EFFETS DE LA PARTICULE ALPHA ET DU NOYAU DE RECUL EMIS LORS DE LA DESINTEGRATION DES ACTINIDES, MAIS AUSSI DE DIFFERENCIER LES EFFETS CAUSES PAR LES PROCESSUS ELECTRONIQUES ET BALISTIQUES. LES VERRES AINSI IRRADIES ONT ETE CARACTERISES PAR DIFFERENTES METHODES, CE QUI A ETE L'OCCASION D'ADAPTER LES PROTOCOLES EXPERIMENTAUX AUX CARACTERISTIQUES SPECIFIQUES DE NOS ECHANTILLONS (ECHANTILLONS DE PETITE TAILLE TRES ISOLANTS, FAIBLE PROFONDEUR IRRADIEE). LES RESULTATS METTENT EN AVANT LE ROLE PARTICULIER DU SODIUM (ELEMENT LE PLUS MOBILE) : ACCUMULATION DE SODIUM A LA SURFACE OBSERVEE PAR SPECTROSCOPIE RUTHERFORD, ACCELERATION APPARENTE DU RELACHEMENT DE SODIUM PAR LIXIVIATION COHERENTE AVEC LES RESULTATS PRECEDENTS. LES SPECTRES RAMAN MONTRENT UNE AUGMENTATION DE LA POLYMERISATION DU VERRE APRES IRRADIATION S'EXPLIQUANT PAR LA MIGRATION DU SODIUM. NOUS RETROUVONS L'EVOLUTION SOUS IRRADIATION DES GRANDEURS MECANIQUES OBSERVEES SUR LES VERRES NUCLEAIRES DOPES (LA DURETE DIMINUE, LA TENACITE AUGMENTE). PARALLELEMENT A CE TRAVAIL EXPERIMENTAL, NOUS AVONS REALISE DES SIMULATIONS PAR DYNAMIQUE MOLECULAIRE D'UN VERRE A 6 OXYDES. NOUS AVONS MONTRE QUE LA PRESENCE DE LA SURFACE INDUIT DES MODIFICATIONS DE LA STRUCTURE SE LIMITANT A 10 A : MODIFICATION DES PROFILS DE CONCENTRATION, DIMINUTION DE LA COORDINENCE (AL, B ET SI). LORS DES CASCADES DE CHOCS BALISTIQUES, IL APPARAIT QUE LES DEPLACEMENTS ATOMIQUES SONT PLUS FACILES PRES DES SURFACES, COMPORTEMENT OBSERVE EGALEMENT LORS DE L'APPLICATION D'UN CHAMP ELECTRIQUE EXTERNE. DANS LA GAMME D'ENERGIE ETUDIEE, L'EFFICACITE DE LA RECONSTRUCTION DE LA STRUCTURE VITREUSE NE SEMBLE PAS AFFECTEE PAR LA PRESENCE DE LA SURFACE.
Download or read book Compr hension structurale des effets d auto irradiation alpha dans les verres written by Géraldine Bureau and published by . This book was released on 2008 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: L’étude de la tenue sous auto-irradiation alpha des verres nucléaires est un élément indispensable à la démonstration de leur comportement à long terme en situation de stockage. A cet effet, ce travail est une contribution à la compréhension de la réponse de la structure vitreuse sous l’effet des interactions nucléaires induites par les noyaux de recul. Afin d’appréhender ces modifications structurales, des études expérimentales ont été entreprises par des techniques de spectroscopies RAMAN et XANES sur des verres irradiés aux ions. Elles ont de plus été complétées par des études de modélisation par Dynamique Moléculaire. Compte tenu de la complexité chimique du verre nucléaire, l’étude de systèmes modèles simples s’est avérée nécessaire pour extraire les mécanismes d’évolutions sous auto-irradiation alpha. Il en ressort sous irradiations aux ions, une conversion partielle des atomes de bore tétracoordonnés en atomes tricoordonnés ainsi qu’une dépolymérisation du réseau silicaté. L’amplitude de ces phénomènes est dépendante de la composition chimique initiale du verre. Un modèle d’évolution de la structure vitreuse sous auto-irradiation alpha a été proposé, établi à partir d’études sur le parallèle entre les effets balistiques et de trempes thermiques. Celui-ci suppose que le passage d’un noyau de recul dans une structure vitreuse va localement déstabiliser le verre le rapprochant d’une structure à très haute température sans pour autant adopter un état d’équilibre thermodynamique. La conversion de coordinence des bore après irradiation peut alors s’expliquer du fait que l’état de coordinence 3 de ces atomes est le plus stable à haute température.
Download or read book Nuclear Waste Conditioning written by France. Commissariat à l'énergie atomique (CEA) and published by Le Moniteur Editions. This book was released on 2009 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1991 with total page 1128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1976 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analytical Methods in the Nuclear Fuel Cycle written by and published by . This book was released on 1972 with total page 610 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 Government Reports Announcements Index written by and published by . This book was released on 1991 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microdosimetry written by Lennart Lindborg and published by CRC Press. This book was released on 2020-10-02 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental microdosimetry deals with the measurement of charged particle energy deposition in tissue equivalent volumes, ranging in size from nanometres to micrometres. Microdosimetry is employed to improve our understanding of the relationship between radiation energy deposition, the resulting biological effects, and the appropriate quantities to be used in characterizing and quantifying radiation quality. Although many reviews and contributions to the field have been published over the past fifty years, this new book is the first to provide a single, up to date, and easily accessible account of experimental microdosimetry. This book is designed to be used in medical, radiation, and health physics courses and by Master's and PhD students. In addition to serving as an introductory text to the field for graduate students, this book will also be of interest as a teaching and reference resource for graduate supervisors and established researchers. Drs. Lennart Lindborg and Anthony Waker have spent a life-time career in experimental microdosimetry research in academic, industrial and regulatory environments and have observed the development of the field from its early days as a recognized discipline; they bring to this book particular knowledge and experience in the design, construction, operation and use of tissue equivalent gas ionization counters and chambers.
Download or read book Short Pulse Laser Interactions With Matter An Introduction written by Paul Gibbon and published by World Scientific. This book was released on 2005-09-05 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents the first comprehensive treatment of the subject, covering the theoretical principles, present experimental status and important applications of short-pulse laser-matter interactions.Femtosecond lasers have undergone dramatic technological advances over the last fifteen years, generating a whole host of new research activities under the theme of “ultrafast science”. The focused light from these devices is so intense that ordinary matter is torn apart within a few laser cycles. This book takes a close-up look at the exotic physical phenomena which arise as a result of this new form of “light-matter” interaction, covering a diverse set of topics including multiphoton ionization, rapid heatwaves, fast particle generation and relativistic self-channeling. These processes are central to a number of exciting new applications in other fields, such as microholography, optical particle accelerators and photonuclear physics.Repository for numerical models described in Chapter 6 can be found at www.fz-juelich.de/zam/cams/plasma/SPLIM/./a
Download or read book Pandex Current Index to Scientific and Technical Literature written by and published by . This book was released on 1971 with total page 1318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the First International Congress of Radiation Protection written by and published by . This book was released on 1968 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book National and International Standardization of Radiation Dosimetry written by International Atomic Energy Agency and published by . This book was released on 1978 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Properties of UO2 written by J. Belle and published by . This book was released on 1957 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Narratives of fear and safety written by Kaisa Kaukiainen and published by BoD - Books on Demand. This book was released on 2020-09-01 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: The essays in this edited volume, written in English and French, tackle the intriguing problems of fear and safety by analysing their various meanings and manifestations in literature and other narrative media. The articles bring forth new, cross-cultural interpretations on fear and safety through examining what kinds of genre-specific means of world-making narratives use to express these two affectivities. The articles also show how important it is to study these themes in order to understand challenges in times of global threats, such as the climate crisis. The main themes of the book are approached from various theoretical perspectives as related to their literary and cultural representations. Recent trends in research, such as affect and risk theory, serve as the basis for the discussion. The articles in the volume also draw from disciplines such as gender studies and trauma studies to examine the threats posed by collective fears and aggression on individuals' lives and propose ways of coping with fear. These themes are addressed also in articles analysing new adaptations of old myths that retell stories of the past. Many of the articles in the volume discuss apocalyptic and dystopian narratives that currently permeate the entire cultural landscape. Dystopian narratives do not only deal with future threats, such as totalitarianism, technocracy, or environmental disasters, but also suggest alternative ways of being and new hopes in the form of political resistance.
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:
