Download or read book Effect of Neutron Irradiation on Thermal Conductivity of Carbon Carbon Fiber Materials at 400 and 600 C in the Fluence Range 1 X 1022 to 1 X 1024 M 2 written by L. Binkele and published by . This book was released on 1994 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of their low atomic number and excellent thermal conductivity, carbon/ carbon fiber materials are seen as potential candidates for plasma-facing components, such as divertors, in Tokamak fusion devices. In the technology phase of Next European Torus (NET) or International Thermonuclear Experimental Reactor (ITER), the surface of a divertor will operate between 400 and 1000°C, and the materials will accumulate a lifetime neutron fluence equivalent to a dpa damage of 0.1. Low doses of neutron irradiation cause a significant decrease in the thermal conductivity of graphitic materials at low temperatures. To quantify the effect, candidate materials such as fine- and superfine-grained graphites (as reference materials), carbon/carbon fiber composites, and an oriented pyrolytic carbon (PyC) were irradiated at 400 and 600°C up to 0.1 dpa. At this fluence and at 400°C, the thermal conductivity (/) is reduced by 40 to 60%, whereas irradiation at 600°C caused a reduction of the l-values at irradiation temperature by about 20 to 40%. This spread seems to be caused by material differences but could be due to the uncertainties in the measurement and neutron fluence.
Download or read book Effects of Radiation on Materials written by Arvind S. Kumar and published by ASTM International. This book was released on 1994 with total page 1319 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineered Materials Abstracts written by and published by . This book was released on 1994-07 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physical Processes of the Interaction of Fusion Plasmas with Solids written by Wolfgang O. Hofer and published by . This book was released on 1996 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent development of large fusion devices achieving near energy break-even scientifically proves the viability of fusion as an energy source. The challenge now facing fusion researchers is surmounting engineering obstacles to make fusion energy practical. Physical Processes of the Interaction of Fusion Plasmas with Solids discusses problems associated with plasma-surface interactions which represent a key issue in achieving engineering as opposed to scientific success. Unlike previous books on the subject, this text is directly related to the broad range of plasma-surface interactions problems encountered in fusion devices. Physical Processes of the Interaction of Fusion Plasmas with Solids provides the specialized international fusion community with a resource that covers the interesting new developments that have occurred with the advent of the larger fusion plasmadevices that have demonstrated near break-even energy. This book addresses problems that are useful for design and fabrication of such devices. The edge plasma Physical sputtering and radiation-enhanced sublimation Chemical erosion Electron emission from solids Control of plasma-surface interactions by thin films Thermal stability Radiation damage in metallic structural materials Radiation damage in carbon materials
Download or read book The Effect of Neutron Irradiation on the Structure and Properties of Carbon Carbon Composite Materials written by TD. Burchell and published by . This book was released on 1994 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-carbon composite materials are used for plasma-facing applications in fusion energy devices. Next generation fusion reactors will produce high energy neutrons which damage the plasma facing materials and degrade their properties. Here the results of two irradiation experiments, HTFC-1 and -2, each containing specimens of carbon-carbon composites are described. Data are reported for the dimensional changes of the materials as a function of fluence in the range 0.5-5 dpa for an irradiation temperature of 600°C. The observed dimensional changes are analyzed in terms of the composite's architecture, fiber precursor, and graphitization temperature. Dimensional change "turnaround" behavior is observed for several of the materials. Strength is shown to increase with increasing neutron fluence for most of the carbon-carbon composites. High temperature thermal conductivity is reported for two 3D carbon-carbon composites, before and after irradiation. Irradiation reduces thermal conductivity by 60%. However, after thermal annealing at 1600°C the reduction in thermal conductivity is as little as 20%.
Download or read book The Engineering Index Annual written by and published by . This book was released on 1994 with total page 2398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its creation in 1884, Engineering Index has covered virtually every major engineering innovation from around the world. It serves as the historical record of virtually every major engineering innovation of the 20th century. Recent content is a vital resource for current awareness, new production information, technological forecasting and competitive intelligence. The world?s most comprehensive interdisciplinary engineering database, Engineering Index contains over 10.7 million records. Each year, over 500,000 new abstracts are added from over 5,000 scholarly journals, trade magazines, and conference proceedings. Coverage spans over 175 engineering disciplines from over 80 countries. Updated weekly.
Download or read book Radiation Damage and Thermal Shock Response of Carbon fiber reinforced Materials to Intense High energy Proton Beams written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have been studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences e"5 × 1020 p/cm2. The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF) selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (~ 5 × 1018 p cm$-$2). In addition, the studied MoGRCF compound grade suffered a high degree of structural degradation while being irradiated in a vacuum after a fluence ~ 5 × 1020 p cm$-$ 2. In conclusion, x-ray diffraction studies on irradiated C/C composites and a carbon-fiber-reinforced Mo-graphite compound revealed (a) low graphitization in the "as-received" 3D C/C and high graphitization in the MoGRCF compound, (b) irradiation-induced graphitization of the least crystallized phases in the carbon fibers of the 2D and 3D C/C composites, (c) increased interplanar distances along the c axis of the graphite crystal with increasing fluence, and (d) coalescence of interstitial clusters after irradiation forming new crystalline planes between basal planes and excellent agreement with fast neutron irradiation effects.
Download or read book Neutron And Gamma ray Irradiation Effects in Composite Organic Insulators written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron irradiations with low .gamma.-ray flux in the Intense Pulsed Neutron Source were carried out on four kinds of cloth-filled organic composites (filler: E-glass or carbon fiber; matrix: epoxy or polyimide resin) and a unidirectional alumina fiber/epoxy composite. The mechanical test was performed at room temperature. Following irradiation at room temperature, the glass/epoxy and glass/polyimide composites degrade significantly at a total neutron fluence of 5.0 x 1018 n/cm2 (1.4 x 1018 n/cm2 for E> 0.1 MeV), while the other composites do not degrade at this fluence. Comparison of this result with that of 6°Co .gamma.-ray irradiations reveals that the 1°B(n, .cap alpha.)7Li reaction in E-glass fibers accelerates the degradation of composite materials by increasing the extent of radiation damage at the fiber/matrix interface. Following irradiation at 5 K, the present composites do not degrade up to a total neutron fluence of 1.0 x 1018 n/cm2 (7.0 x 1017 n/cm2 for E> 0.1 MeV). The mechanical test performed at 77 K on electron-irradiated composites, on the other hand, shows that the rate of degradation with dose is appreciably greater in the 77 K test than in the room-temperature test.
Download or read book Advances in High Temperature Gas Cooled Reactor Fuel Technology written by International Atomic Energy Agency and published by . This book was released on 2012-06 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication reports on the results of a coordinated research project on advances in high temperature gas cooled reactor (HTGR) fuel technology and describes the findings of research activities on coated particle developments. These comprise two specific benchmark exercises with the application of HTGR fuel performance and fission product release codes, which helped compare the quality and validity of the computer models against experimental data. The project participants also examined techniques for fuel characterization and advanced quality assessment/quality control. The key exercise included a round-robin experimental study on the measurements of fuel kernel and particle coating properties of recent Korean, South African and US coated particle productions applying the respective qualification measures of each participating Member State. The summary report documents the results and conclusions achieved by the project and underlines the added value to contemporary knowledge on HTGR fuel.
Download or read book Neutron Irradiation Effects on the Mechanical Properties of Thorium and Thorium carbon Alloy written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of neutron exposure to 3.0 x 1018 neutrons/cm2 on the mechanical properties of thorium and thorium-carbon alloy are described. Tensile measurements were done at six different test temperatures from 4°K to 503°K and at two strain rates. Thorium and thorium-carbon alloy are shown to display typical radiation hardening like other face-centered cubic metals. The yield drop phenomenon of the thorium-carbon alloy is unchanged after irradiation. The variation of shear stress and effective shear stress with test temperature was fitted to Seeger's and Fleischer's equations for irradiated and unirradiated thorium and thorium-carbon alloy. Neutron irradiation apparently contributes an athermal component to the yield strength. However, some thermal component is detected in the low temperature range. Strain-rate parameter is increased and activation volume is decreased slightly for both kinds of metal after irradiation.
Download or read book Magnetic Fusion Technology written by Thomas J. Dolan and published by Springer Science & Business Media. This book was released on 2014-02-10 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Fusion Technology describes the technologies that are required for successful development of nuclear fusion power plants using strong magnetic fields. These technologies include: • magnet systems, • plasma heating systems, • control systems, • energy conversion systems, • advanced materials development, • vacuum systems, • cryogenic systems, • plasma diagnostics, • safety systems, and • power plant design studies. Magnetic Fusion Technology will be useful to students and to specialists working in energy research.
Download or read book Basic Studies in the Field of High temperature Engineering written by Nihon Genshiryoku Kenkyūjo and published by Paris, France : Nuclear Energy Agency, Organisation for Economic Co-operation and Development. This book was released on 2002 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to increasing interest in high-temperature, gas-cooled reactors (HTGRs) in many countries and the need for improved materials for nuclear applications in high-temperature environments, the NEA organised a Second Information Exchange Meeting on Basic Studies in the Field of High-temperature Engineering. These proceedings provide an overview of the activities being carried out in eight countries, the improvement of material properties for HTGR application, in-core monitoring methods and properties of irradiated graphite, and HTGR fuel fabrication and performance.
Download or read book Properties of Materials written by Robert E. Newnham and published by Oxford University Press. This book was released on 2005 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crystals are sometimes called 'Flowers of the Mineral Kingdom'. In addition to their great beauty, crystals and other textured materials are enormously useful in electronics, optics, acoustics and many other engineering applications. This richly illustrated text describes the underlying principles of crystal physics and chemistry, covering a wide range of topics and illustrating numerous applications in many fields of engineering using the most important materials today. Tensors, matrices, symmetry and structure-property relationships form the main subjects of the book. While tensors and matrices provide the mathematical framework for understanding anisotropy, on which the physical and chemical properties of crystals and textured materials often depend, atomistic arguments are also needed to quantify the property coefficients in various directions. The atomistic arguments are partly based on symmetry and partly on the basic physics and chemistry of materials. After introducing the point groups appropriate for single crystals, textured materials and ordered magnetic structures, the directional properties of many different materials are described: linear and nonlinear elasticity, piezoelectricity and electrostriction, magnetic phenomena, diffusion and other transport properties, and both primary and secondary ferroic behavior. With crystal optics (its roots in classical mineralogy) having become an important component of the information age, nonlinear optics is described along with the piexo-optics, magneto-optics, and analogous linear and nonlinear acoustic wave phenomena. Enantiomorphism, optical activity, and chemical anisotropy are discussed in the final chapters of the book.
Download or read book Heat Capacity and Thermal Expansion at Low Temperatures written by T.H.K. Barron and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The birth of this monograph is partly due to the persistent efforts of the General Editor, Dr. Klaus Timmerhaus, to persuade the authors that they encapsulate their forty or fifty years of struggle with the thermal properties of materials into a book before they either expired or became totally senile. We recognize his wisdom in wanting a monograph which includes the closely linked properties of heat capacity and thermal expansion, to which we have added a little 'cement' in the form of elastic moduli. There seems to be a dearth of practitioners in these areas, particularly among physics postgraduate students, sometimes temporarily alleviated when a new generation of exciting materials are found, be they heavy fermion compounds, high temperature superconductors, or fullerenes. And yet the needs of the space industry, telecommunications, energy conservation, astronomy, medical imaging, etc. , place demands for more data and understanding of these properties for all classes of materials - metals, polymers, glasses, ceramics, and mixtures thereof. There have been many useful books, including Specific Heats at Low Tempera tures by E. S. Raja Gopal (1966) in this Plenum Cryogenic Monograph Series, but few if any that covered these related topics in one book in a fashion designed to help the cryogenic engineer and cryophysicist. We hope that the introductory chapter will widen the horizons of many without a solid state background but with a general interest in physics and materials.
Download or read book High Temperature Ceramic Matrix Composites written by R. Naslain and published by Woodhead Publishing Limited. This book was released on 1993 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Electrolyte Fuel Cell Durability written by Felix N. Büchi and published by Springer Science & Business Media. This book was released on 2009-02-08 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers a significant number of R&D projects, performed mostly after 2000, devoted to the understanding and prevention of performance degradation processes in polymer electrolyte fuel cells (PEFCs). The extent and severity of performance degradation processes in PEFCs were recognized rather gradually. Indeed, the recognition overlapped with a significant number of industrial dem- strations of fuel cell powered vehicles, which would suggest a degree of technology maturity beyond the resaolution of fundamental failure mechanisms. An intriguing question, therefore, is why has there been this apparent delay in addressing fun- mental performance stability requirements. The apparent answer is that testing of the power system under fully realistic operation conditions was one prerequisite for revealing the nature and extent of some key modes of PEFC stack failure. Such modes of failure were not exposed to a similar degree, or not at all, in earlier tests of PEFC stacks which were not performed under fully relevant conditions, parti- larly such tests which did not include multiple on–off and/or high power–low power cycles typical for transportation and mobile power applications of PEFCs. Long-term testing of PEFCs reported in the early 1990s by both Los Alamos National Laboratory and Ballard Power was performed under conditions of c- stant cell voltage, typically near the maximum power point of the PEFC.
Download or read book Nickel and Its Alloys written by Samuel Jacob Rosenberg and published by . This book was released on 1968 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
