Download or read book Mesure de l amplitude d une onde de plasma cr e par sillage laser guid written by Franck Wojda and published by . This book was released on 2010 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: L’interaction d’une impulsion laser intense et de courte durée avec un plasma permet de produire une onde de plasma de grande amplitude dans son sillage, auquel est associé un champ électrique longitudinal. Celui-ci peut être utilisé pour accélérer des électrons relativistes injectés dans l'onde jusqu’à de grandes énergies - de l’ordre du GeV - sur de courtes distances - quelques centimètres - au regard des distances dans les accélérateurs conventionnels. Le contrôle des caractéristiques du faisceau d’électrons lors du processus d’accélération est fondamental pour réaliser un étage d’accélération laser-plasma utilisable. Le travail de thèse a porté sur la création et la caractérisation d’une onde de plasma en régime faiblement non linéaire sur une longueur de plusieurs centimètres. Des tubes capillaires sont utilisés pour guider le faisceau laser sur ces distances tout en maintenant une intensité suffisante (~1017 W/cm2). Le faisceau laser guidé ionise le gaz contenu dans le tube et crée l’onde de plasma. Un diagnostic optique reposant sur la modification du spectre de l’impulsion laser a été utilisé pour déterminer l’amplitude de l’onde de plasma le long du tube. Sa dépendance en fonction de la pression de remplissage du gaz, de la longueur du capillaire et de l'énergie laser, a été étudiée. Les résultats expérimentaux comparés aux résultats analytiques et de modélisation furent en excellent accord. montrent que le champ électrique associé à l'onde de plasma est compris entre 1 et 10 GV/m sur une longueur allant jusqu’à 8 cm. Ce travail a permis de montrer la possibilité de créer de façon contrôlée une onde de plasma en régime faiblement non linéaire.
Download or read book ACCELERATION DE PARTICULES DANS UN PLASMA PAR UNE ONDE DE SILLAGE PROVOQUEE PAR UNE BREVE IMPULSION LASER DE FORTE INTENSITE written by DENIS.. TEYCHENNE and published by . This book was released on 1994 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: DANS CETTE THESE, NOUS ETUDIONS L'ONDE PLASMA RELATIVISTE DE GRANDE AMPLITUDE ET L'ACCELERATION DE PARTICULES PRODUITE DANS UNE TELLE STRUCTURE. EN EFFET, LE PASSAGE D'UNE COURTE IMPULSION LASER (INFERIEURE A 1 PICOSECONDE.) DE FORTE INTENSITE (SUPERIEURE A 10#1#8 W/CM#2) DANS UN PLASMA SOUS-CRITIQUE GENERE IMMEDIATEMENT DERRIERE CELLE-CI, UNE ONDE PLASMA DE GRANDE AMPLITUDE APPELEE ONDE DE SILLAGE. CETTE DERNIERE POSSEDE DEUX CARACTERISTIQUES IMPORTANTES POUR L'ACCELERATION: UN CHAMP ELECTRIQUE INTENSE (ENTRE 10 ET 100 GV/M) ET UNE VITESSE DE PHASE PROCHE DE CELLE DE LA LUMIERE. LA PREMIERE PARTIE EST CONSACREE AUX PROPRIETES DE L'ONDE DE SILLAGE QUI EST ENGENDREE PAR LES FORCES PONDEROMOTRICE DE L'IMPULSION LASER. L'ANALYSE THEORIQUE DETAILLEE DES PARAMETRES PHYSIQUES (CHAMP ET POTENTIEL ELECTRIQUE, MODULATION DE DENSITE, LONGUEUR D'ONDE, LONGUEUR OPTIMALE DE L'IMPULSION, CONDITIONS DE DEFERLEMENT ET TRANSFERT D'ENERGIE ENTRE LE PLASMA ET L'IMPULSION LASER) EST EFFECTUEE AVEC UN PROFIL RECTANGULAIRE ET AVEC UN ECLAIREMENT LASER ET UNE DENSITE DE PLASMA QUELCONQUES. ON COMPARE LES AVANTAGES ET LES INCONVENIENTS DE L'EFFET DE SILLAGE ET DU BATTEMENT D'ONDES. UNE ETUDE NUMERIQUE EST EGALEMENT REALISEE AVEC UN PROFIL EN ENERGIE DE L'IMPULSION PLUS REALISTE (SINUS-CARRE). ELLE PERMET DE QUANTIFIER, D'UNE PART, L'INFLUENCE DES ECLAIREMENTS LASER ET D'AUTRE PART, L'IMPACT DE LA LONGUEUR DE L'IMPULSION SUR L'ONDE DE SILLAGE. LA DEUXIEME PARTIE PRESENTE L'ACCELERATION DE PARTICULE DANS UNE ONDE PLASMA RELATIVISTE. DANS UN PREMIER TEMPS, ON CALCULE RIGOUREUSEMENT LES LONGUEURS D'ACCELERATION D'UNE PARTICULE TEST PIEGEE DANS UNE ONDE PLASMA SINUSOIDALE OU DANS UNE ONDE PLASMA NON-LINEAIRE. PUIS, DANS UN DEUXIEME TEMPS, ON DETERMINE LE MEILLEUR COMPROMIS ENTRE LE GAIN D'ENERGIE DES PARTICULES ET LA LONGUEUR DU PLASMA
Download or read book ETUDE DU SILLAGE LASER written by Fabien Dorchies and published by . This book was released on 1998 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: DANS LE BUT D'ACCELERER DES PARTICULES CHARGEES AVEC DES CHAMPS ELECTRIQUES SUPERIEURS AUX LIMITES ACTUELLES DES CAVITES ACCELERATRICES CONVENTIONNELLES (DE L'ORDRE DE 100 MV/M), PLUSIEURS MECANISMES UTILISANT UNE ONDE PLASMA ELECTRONIQUE EXCITEE PAR LA FORCE PONDEROMOTRICE D'UNE IMPULSION LASER INTENSE ONT ETE PROPOSES. PARMI CEUX-CI, LE SILLAGE LASER SEMBLE LE PLUS PROMETTEUR : UNE IMPULSION LASER ULTRA-COURTE ( 1 PS) ET ULTRA-INTENSE ( 10#1#7 W.CM##2) SE PROPAGEANT DANS UN PLASMA SOUS-DENSE (DE L'ORDRE DE 10#1#7 ELECTRONS PAR CM#3), EXCITE DANS SON SILLAGE UNE ONDE PLASMA ELECTRONIQUE DE FORTE AMPLITUDE. LE CHAMP ELECTRIQUE LONGITUDINAL ASSOCIE A CETTE ONDE PEUT ETRE TRES ELEVE ET ACCELERER EFFICACEMENT DES ELECTRONS INJECTES. CETTE THESE PRESENTE UNE ETUDE EXPERIMENTALE DE CE MECANISME. DANS UN PREMIER TEMPS, L'ONDE PLASMA EXCITEE PAR SILLAGE LASER A ETE MESUREE OPTIQUEMENT EN UTILISANT LE DIAGNOSTIC D'INTERFEROMETRIE FREQUENTIELLE. CETTE PREMIERE SERIE D'EXPERIENCES A PERMIS DE MONTRER LA VALIDITE DE LA THEORIE LINEAIRE DU SILLAGE DANS UN REGIME FORTEMENT RADIAL, JUSQU'A UNE AMPLITUDE RELATIVE DE L'ORDRE DE 100%. UNE EXPERIENCE A ETE CONCUE ET ETUDIEE DANS UN REGIME LONGITUDINAL. LORS D'UNE AUTRE EXPERIENCE, DES ELECTRONS ONT ETE INJECTES DANS L'ONDE PLASMA. DES ELECTRONS ACCELERES PAR UN CHAMP DE L'ORDRE DE 1 GV/M ONT ETE OBSERVES. A NOUVEAU, LA THEORIE LINEAIRE DU SILLAGE PERMET DE RENDRE COMPTE DES RESULTATS OBSERVES. CETTE EXPERIENCE A NOTAMMENT MONTRE L'INFLUENCE DES CHAMPS ELECTRIQUES RADIAUX ASSOCIES A L'ONDE PLASMA SUR LA QUALITE DE L'ACCELERATION. CETTE ACCELERATION EST LIMITEE PAR LA LONGUEUR SUR LAQUELLE EXISTE L'ONDE PLASMA, C'EST A DIRE PAR LA LONGUEUR DE RAYLEIGH DU FAISCEAU LASER. UN MOYEN D'AUGMENTER LE GAIN D'ENERGIE DES ELECTRONS EST DE GUIDER L'IMPULSION LASER INTENSE SUR DE PLUS GRANDES LONGUEURS. DANS CETTE OPTIQUE, UNE PREMIERE EXPERIENCE DE GUIDAGE DANS UN CAPILLAIRE DIELECTRIQUE CREUX A ETE REALISEE.
Download or read book Aircraft Fire Safety written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Propulsion and Energetics Panel. Symposium and published by . This book was released on 1997 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hypersonic Flow Theory written by Wallace Hayes and published by Elsevier. This book was released on 2012-12-02 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypersonic Flow Theory presents the fundamentals of fluid mechanics, focusing on the hypersonic flow theory and approaches in theoretical aerodynamics. This book discusses the assumptions underlying hypersonic flow theory, unified supersonic-hypersonic similitude, two-dimensional and axisymmetric bodies, and circular cylinder. The constant-streamtube-area approximation, streamtube-continuity methods, and tangent-wedge and tangent-cone are also deliberated. This text likewise covers the similar laminar boundary layer solutions, bluntness induced interactions on slender bodies, and free molecule transfer theory. The dynamics of hypersonic flight or hypersonic wing theory, magnetohydrodynamic theory, or any developments involving treatment of the Boltzmann equation are not included. This publication is intended for hypersonic aerodynamicists, students, and researchers conducting work on the hypersonic flow phenomena.
Download or read book Reason Illusion and Passion written by Émilie du Châtelet and published by . This book was released on 2019-09-16 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: The amazing scientist, mathematician, philosopher Émilie du Châtelet (1706-49) has widely been hailed as a rare female intellectual in the Enlightenment. At the same time, her own ideas and contributions remain largely unknown and her writings are rarely read. This is unfortunate, since she has interesting contributions to and explanations of physics, metaphysics, religion, translation, the equality of the sexes, and ethics.This book is a selection of du Châtelet's philosophical writings, in new English translations: -Foreword to "Foundations of Physics"-On the Principles of Our Knowledge (From "Foundations of Physics")-On the Existence of God (From "Foundations of Physics")-On Liberty-Translator's Preface to Mandeville's "Fable of the Bees"-On the Resurrection of the Dead (from "Examinations of the Bible")-On Happiness
Download or read book A Parallel Finite Volume Algorithm for Large eddy Simulation of Turbulent Flows written by Trong T. Bui and published by . This book was released on 1998 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Light Filaments written by Jean-Claude Diels and published by IET. This book was released on 2022 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited volume starts with tutorials about the science of filamentation before presenting in-depth chapters on the latest research, technologies and applications. It cover wide aspects of light filaments considering various mediums of propagation, with structured or single filaments, and filaments of different colours, as well as combined filaments. It also includes a wide range of applications from strong field ionisation and molecular properties to laser development and beam shaping, THz, lasing in air and supercontinuum generation.
Download or read book Auxiliary power systems papers presented at the Propulsion and Energetics Panel 61st B specialists meeting held in Copenhagen Denmark 30 31 May 1983 written by AGARD. and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA SP written by and published by . This book was released on 1962 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Confronting Poverty in Iraq written by World Bank and published by World Bank Publications. This book was released on 2011-01-10 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report provides the most comprehensive and rigorous analysis of Iraqi income and expenditure in several decades. The report makes extensive use of the Iraq Household Socio-Economic Survey, the first nationwide income and expenditure survey since 1988. IHSES data is complemented income and expenditure data from a wide range of other measures of living standards, allowing us to analyze living standards in a holistic way. The analysis presented here was performed with two main goals first, to inform the Government s Poverty Reduction Strategy; and second, to serve as a baseline for future assessments of changes in living standards and the identification of critical issues for deeper examination. Iraqi living standards have two unusual characteristics. First, they have fallen over the past generation. Second, they feature surprisingly little inequality. These characteristics are both rooted in Iraq s recent history of authoritarian government, war, military occupation, insurgency, and civil strife leading to infrastructure destruction and population displacement. There have been few opportunities for individuals to prosper from professional or entrepreneurial activities. Decades of neglected investment have resulted in deterioration of social services and economic infrastructure. Consequently, individuals have lacked capabilities to prosper and an investment climate conducive to prosperity. School enrollment and life expectancy have declined. Extremely low returns to education reflect the combination of poor educational quality and lack of employment opportunities. In terms of economic infrastructure, access to reliable electricity and water, and even access to paved roads are low, are further reflections of decades of neglect. While the upper end of the distribution has been pulled down by a lack of opportunities, the lower end has been supported by direct government provision of food. The Public Distribution System (PDS) provides 85 percent of food needs. While PDS has been useful as a safety net for the poor and the vulnerable, the system is expensive, inefficient, and fiscally risky. Indeed, PDS food rations account for a far greater share of public spending than does education or health. Going forward, Iraq faces two main challenges. First, although Iraq does not have to develop from scratch, it faces a formidable challenge in re-development. Second, a shift by the Government is required from direct provision of basic subsistence toward investment in human capacities. The Government can provide an enabling environment through investments in economic infrastructure and services to business and citizens, thus allowing the population to make productive use of education and their own labor. Both challenges are now being taken up by the Poverty Reduction Strategy, which articulates a detailed set of required actions and outlines priorities for government spending.
Download or read book Conceptual Modeling for Traditional and Spatio Temporal Applications written by Christine Parent and published by Springer Science & Business Media. This book was released on 2006-09-02 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: From environmental management to land planning and geo-marketing, the number of application domains that may greatly benefit from using data enriched with spatio-temporal features is expanding very rapidly. This book shows that a conceptual design approach for spatio-temporal databases is both feasible and easy to apprehend. While providing a firm basis through extensive discussion of traditional data modeling concepts, the major focus of the book is on modeling spatial and temporal information.
Download or read book Internal Flow written by E. M. Greitzer and published by Cambridge University Press. This book was released on 2007-02-26 with total page 739 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the analysis and behaviour of internal flows encountered in propulsion systems, fluid machinery (compressors, turbines and pumps) and ducts (diffusers, nozzles and combustion chambers). The focus is on phenomena that are important in setting the performance of a broad range of fluid devices. The authors show that even for complex processes one can learn a great deal about the behaviour of such devices from a clear understanding and rigorous use of basic principles. Throughout the book they illustrate theoretical principles by reference to technological applications. The strong emphasis on fundamentals, however, means that the ideas presented can be applied beyond internal flow to other types of fluid motion. The book equips students and practising engineers with a range of new analytical tools. These tools offer enhanced interpretation and application of both experimental measurements and the computational procedures that characterize modern fluids engineering.
Download or read book Cambridge Yearbook of European Legal Studies Vol 13 2010 2011 written by Catherine Barnard and published by Bloomsbury Publishing. This book was released on 2011-12-15 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Cambridge Yearbook of European Legal Studies provides a forum for the scrutiny of significant issues in EU Law, the law of the European Convention on Human Rights, and Comparative Law with a 'European' dimension, and particularly those issues which have come to the fore during the year preceding publication. The contributions appearing in the collection are commissioned by the Centre for European Legal Studies (CELS) Cambridge, a research centre in the Law Faculty of the University of Cambridge specialising in European legal issues. The papers presented are at the cutting edge of the fields which they address, and reflect the views of recognised experts drawn from the University world, legal practice, and the institutions of both the EU and its Member States. Inclusion of the comparative dimension brings a fresh perspective to the study of European law, and highlights the effects of globalisation of the law more generally, and the resulting cross fertilisation of norms and ideas that has occurred among previously sovereign and separate legal orders. The Cambridge Yearbook of European Legal Studies is an invaluable resource for those wishing to keep pace with legal developments in the fast moving world of European integration. INDIVIDUAL CHAPTERS Please click on the link below to purchase individual chapters from Volume 13 through Ingenta Connect: www.ingentaconnect.com SUBSCRIPTION TO SERIES To place an annual online subscription or a print standing order through Hart Publishing please click on the link below. Please note that any customers who have a standing order for the printed volumes will now be entitled to free online access. www.hartjournals.co.uk/cyels/subs Editorial Advisory Board: Albertina Albors-Llorens, John Bell, Alan Dashwood, Simon Deakin, David Feldman, Richard Fentiman, Angus Johnston, John Spencer Founding Editors: Alan Dashwood and Angela Ward Ius Commune Prize 2012 Alexandre Saydé wrote Chapter 15 in this volume entitled: 'One Law, Two Competitions: An Enquiry into the Contradictions of Free Movement Law' and we are delighted to announce that he has been awarded the Ius Commune Prize 2012.
Download or read book Stress corrosion Cracking of Titanium written by and published by . This book was released on 1966 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Cross Polity Survey written by Arthur S. Banks and published by MIT Press (MA). This book was released on 1971-02-15 with total page 1416 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this unique adaptation of the "cross-cultural" method to comparative politics, a computer is used to compare all of the 115 independent governments in the world. The result is a body of readable two-way cross-classifications from which the major patterns of political phenomena can be perceived at a glance.
Download or read book Struggles in the State written by George Armstrong Kelly and published by John Wiley & Sons. This book was released on 1970 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:
