Download or read book METHODES D ANALYSES DES SIGNAUX MULTI EXPONENTIELS UTILISES EN SPECTROSCOPIE ELECTRIQUE DES DEFAUTS PROFONDS DANS LES SEMICONDUCTEURS written by Auguste Le Bloa and published by . This book was released on 1986 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: METHODE DE CARACTERISATION DES DEFAUTS PROFONDS DANS LES SEMICONDUCTEURS A PARTIR DE L'ANALYSE DU TRANSITOIRE DE CAPACITE D'UNE DIODE. COMPARAISON DES METHODES DE SPECTROMETRIE TRANSITOIRE DE NIVEAU PROFOND (STNP) AUX METHODES STNP DOUBLE CORRELATION ET PHOTOCAPACITIVES. UNE NOUVELLE METHODE EST MISE EN OEUVRE QUI COMBINE LA SPECTROMETRIE TRANSITOIRE DE CAPACITE A L'AIDE D'UNE TRANSFORMEE DE FOURIER.ETUDE GAAS COMPENSE PAR L'IMPLANTATION D'OXYGENE DE SICILIUM PAR MESURE DE LA CONCENTRATION EN ELECTRONS
Download or read book tude de semi conducteurs par spectroscopie d excitation coh rente multidimensionnelle written by Pascal Grégoire and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: La spectroscopie multidimensionnelle est une technique d'optique ultrarapide qui permet de révéler divers mécanismes cohérents, tant électroniques que vibrationnels. Avec une séquence contrôlée d'impulsions laser, on peut extraire les corrélations entre différents niveaux énergétiques d'un matériau ou d'un composé et suivre leur évolution avec une résolution temporelle de l'ordre de la femtoseconde. Le schéma expérimental utilisé correspond à une technique d'excitation, où une séquence de quatre impulsions colinéaires modulées en phase génère les signaux non linéaires d'intérêt. Ceux-ci sont isolés à travers la photoluminescence totale de l'échantillon par une méthode de détection synchrone et permettent de construire un spectre 2D. La spectroscopie d'excitation multidimensionnelle est appliquée pour une première fois à l'étude de matériaux semi-conducteurs variés. Elle permet de s'affranchir du désordre et de mesurer la largeur homogène d'un polymère semi-conducteur, le P3HT, un matériau modèle en électronique organique. La mesure confirme la nature des photoexcitations du P3HT, soit un exciton délocalisé en 2D, sa fonction d'onde s'étendant le long des chaines de polymère ainsi qu'entre chaines adjacentes. La largeur homogène ne variant pas avec la température, on peut en déduire que le désordre statique limite la longueur de cohérence de l'exciton même à température pièce. La réponse expérimentale d'un dispositif photovotaïque à base de pérovskite permet d'illustrer un cas où la technique d'excitation n'est pas applicable en spectroscopie 2D. Un mélange de populations, identifiable par une dépendance sous-linéaire de l'émission en fonction de l'intensité d'excitation, cause alors un signal incohérent qui camoufle le signal multidimensionnel cohérent. Un modèle théorique révèle la ressemblance entre ces deux signaux, ressemblance toutefois fortuite car le signal incohérent contient simplement l'information sur la réponse linéaire de l'échantillon, on ne peut en déduire des corrélations entre les niveaux énergétiques. La modélisation du mélange de populations et des simulations de la réponse cohérente 2D permettent de déterminer quels types de matériaux sont adaptés pour la technique d'excitation et quelles sont les évidences d'une contamination de la mesure par le signal incohérent. Le mélange de populations contient en soit des informations intéressantes sur la dynamique des excitations optiques, comme le montre notre étude d'une microcavité à polaritons à base de GaAs/AlGaAs. Le polariton est une quasi-particule hybride lumière-matière se manifestant lors du couplage fort entre un exciton et un photon piégé dans une microcavité optique. Au delà d'une certaine densité critique, un gaz de polaritons peu effectuer une transition de phase vers un condensat de Bose-Einstein, provoquant une émission de lumière cohérente ayant une intensité fortement non linéaire en fonction de la densité de polaritons. La relaxation stimulée des polaritons prévient ainsi la mesure d'un spectre 2D par la technique d'excitation, le mélange de populations y étant très important au delà du seuil de condensation. Il permet toutefois de révéler le temps de formation du condensat et il contient la signature des différents mécanismes en jeux lors de la thermalisation.
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 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 Radionuclide Standardization written by George I. Coats and published by . This book was released on 1967 with total page 48 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 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.
Download or read book Ecological Consequences of Climate Change written by Erik A. Beever and published by CRC Press. This book was released on 2016-04-19 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contemporary climate change is a crucial management challenge for wildlife scientists, conservation biologists, and ecologists of the 21st century. Climate fingerprints are being detected and documented in the responses of hundreds of wildlife species and numerous ecosystems around the world. To mitigate and accommodate the influences of climate ch
Download or read book Reactor Dosimetry written by Harry Farrar and published by ASTM International. This book was released on 1994 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 8th ASTM-Euratom Symposium, held in Vail, Colorado, Aug.-Sept. 1993, to provide a forum for experts to discuss their latest results under the broad theme of dosimetry for the correlation of radiation effects. Preceded by a summary of the keynote presentations and followed by summa
Download or read book Nuclear Engineering Handbook written by Kenneth D. Kok and published by CRC Press. This book was released on 2016-10-03 with total page 1328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building upon the success of the first edition, the Nuclear Engineering Handbook, Second Edition, provides a comprehensive, up-to-date overview of nuclear power engineering. Consisting of chapters written by leading experts, this volume spans a wide range of topics in the areas of nuclear power reactor design and operation, nuclear fuel cycles, and radiation detection. Plant safety issues are addressed, and the economics of nuclear power generation in the 21st century are presented. The Second Edition also includes full coverage of Generation IV reactor designs, and new information on MRS technologies, small modular reactors, and fast reactors.
Download or read book K Zone Prank Patrol written by and published by . This book was released on 2010 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Play pranks and score laughs from your friends and family! Your day can sometimes be a total drag, but with some creative thinking and the help of the pranks in this book, you can make it a barrel of laughs! Get your friends in on the act! Pranks are ranked so kids can determine the likely level of punishment, from the most benign ('Clean Your Bedroom') to the most dare-devilish ('Xtreme Grounding Guaranteed')! So, PRANK AT YOUR OWN RISK!
