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Tensile Tests Of Niobium Material For Srf Cavities
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Book Synopsis Tensile Tests of Niobium Material for SRF Cavities by :
Download or read book Tensile Tests of Niobium Material for SRF Cavities written by and published by . This book was released on 2009 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical tests of cavity-grade niobium samples were conducted to provide engineering information for the certification of 3rd-harmonic superconducting radio-frequency cavities and cryomodules. Large changes of mechanical properties occur throughout the cavity fabrication process due to the cold work introduced by forming, the heating introduced by electron beam welding, and the recovery of cold work during the anneal used to degas hydrogen after chemical processing. Data is provided here to show the different properties at various stages of fabrication, including both weld regions and samples from the bulk niobium far away from the weld. Measurements of RRR were used to assure that any contamination during annealing was negligible.
Book Synopsis Mechanical Properties of Niobium Radio-frequency Cavities by :
Download or read book Mechanical Properties of Niobium Radio-frequency Cavities written by and published by . This book was released on 2015 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radio-frequency cavities made of bulk niobium are one of the components used in modern particle accelerators. The mechanical stability is an important aspect of cavity design, which typically relies on finite-element analysis simulations using material properties from tensile tests on sample. This contribution presents the results of strain and resonant frequency measurements as a function of a uniform pressure up to 722 kPa, applied to single-cell niobium cavities with different crystallographic structure, purity and treatments. In addition, burst tests of high-purity multi-cell cavities with different crystallographic structure have been conducted up to the tensile strength of the material. Finite-element analysis of the single-cell cavity geometry is in good agreement with the observed behavior in the elastic regime assuming a Young's modulus value of 88.5 GPa and a Poisson's ratio of 0.4, regardless of crystallographic structure, purity or treatment. However, the measured yield strength and tensile strength depend on crystallographic structure, material purity and treatment. In particular, the results from this study show that the mechanical properties of niobium cavities with large crystals are comparable to those of cavities made of fine-grain niobium.
Book Synopsis Mechanical Properties of Niobium Cavities by :
Download or read book Mechanical Properties of Niobium Cavities written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanical stability of bulk Nb cavity is an important aspect to be considered in relation to cavity material, geometry and treatments. Mechanical properties of Nb are typically obtained from uniaxial tensile tests of small samples. In this contribution we report the results of measurements of the resonant frequency and local strain along the contour of single-cell cavities made of ingot and fine-grain Nb of different purity subjected to increasing uniform differential pressure, up to 6 atm. Measurements have been done on cavities subjected to different heat treatments. Good agreement between finite element analysis simulations and experimental data in the elastic regime was obtained with a single set of values of Young's modulus and Poisson's ratio. The experimental results indicate that the yield strength of medium-purity ingot Nb cavities is higher than that of fine-grain, high-purity Nb.
Book Synopsis Fabrication of Niobium Sheet for RF Cavities by : Shreyas Balachandran
Download or read book Fabrication of Niobium Sheet for RF Cavities written by Shreyas Balachandran and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigated the microstructure and mechanical property of RRR(high purity) and RG (low purity) niobium (Nb) sheet material. RRR Nb is used in the fabrication RF cavities. Our method involves processing bulk niobium by equal channel angular extrusion (ECAE) and then cross rolling to obtain sheets. This work is a study of the effect different thermomechanical processing variables have on the microstructure niobium sheets. Recrystallization behaviors strongly depended on the purity levels. Tensile tests on sheets clearly indicated the anisotropy in the sheet material. The ductility of the sheet was found to be the largest at an angle of 45° to the rolling direction. There was no apparent relationship observed in the yielding behavior in the different samples. The formability of the sheet measured by the anisotropy ratio suggested a strong dependence of anisotropy on texture. Texture results obtained show that different routes of ECAE can lead to variety of textures in final sheet material. Correlations between the microstructure and the ECAE routes suggest that effective control of microstructure is possible by the thermomechanical steps followed in this study.
Book Synopsis Proceedings of the 2nd World Congress on Integrated Computational Materials Engineering (ICME) by : Mei Li
Download or read book Proceedings of the 2nd World Congress on Integrated Computational Materials Engineering (ICME) written by Mei Li and published by Springer. This book was released on 2016-12-19 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents a collection of papers presented at the 2nd World Congress on Integrated Computational Materials Engineering (ICME), a specialty conference organized by The Minerals, Metals & Materials Society (TMS).
Book Synopsis Materials and Surface Aspects in the Development of SRF Niobium Cavities by : Claire Antoine
Download or read book Materials and Surface Aspects in the Development of SRF Niobium Cavities written by Claire Antoine and published by . This book was released on 2012 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Physical Properties of Niobium and Specifications for Fabrication of Superconducting Cavities by :
Download or read book Physical Properties of Niobium and Specifications for Fabrication of Superconducting Cavities written by and published by . This book was released on 2011 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is important to distinguish among the properties of niobium, the ones that are related to the cavity's SRF performances, the formability of the material, and the mechanical behavior of the formed cavity. In general, the properties that dictate each of the above mentioned characteristics have a detrimental effect on one another and in order to preserve the superconducting properties without subduing the mechanical behavior, a balance has to be established. Depending on the applications, some parameters become less important and an understanding of the physical origin of the requirements might help in this optimization. SRF applications require high purity niobium (high RRR), but pure niobium is very soft from fabrication viewpoint. Moreover conventional fabrication techniques tend to override the effects of any metallurgical process meant to strengthen it. As those treatments dramatically affect the forming of the material they should be avoided. These unfavorable mechanical properties have to be accounted for in the design of the cavities rather than in the material specification. The aim of this paper is to review the significance of the important mechanical properties used to characterize niobium and to present the optimal range of values. Most of the following information deals with the specification of sheets for cell forming unless otherwise noted.
Book Synopsis Review of Ingot Niobium as a Material for Superconducting Radiofrequency Accelerating Cavities by :
Download or read book Review of Ingot Niobium as a Material for Superconducting Radiofrequency Accelerating Cavities written by and published by . This book was released on 2014 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a result of collaboration between Jefferson Lab and niobium manufacturer Companhia Brasileira de Metalurgia e Mineração (CBMM), ingot niobium was explored as a possible material for superconducting radiofrequency (SRF) cavity fabrication. The first single cell cavity from large-grain high purity niobium was fabricated and successfully tested at Jefferson Lab in 2004. This work triggered research activities in other SRF laboratories around the world. The large-grain (LG) niobium became not only an interesting alternative material for cavity builders, but also material scientists and surface scientists were eager to participate in the development of this technology. Many single cell cavities made from material of different suppliers have been tested successfully and several multi-cell cavities have shown performances comparable to the best cavities made from standard fine-grain niobium. Several 9-cell cavities fabricated by Research Instruments and tested at DESY exceeded the best performing fine grain cavities with a record accelerating gradient of Eacc=45.6 MV/m. The quality factor of those cavities was also higher than that of fine-grain (FG) cavities processed with the same methods. Such performance levels push the state-of-the art of SRF technology and are of great interest for future accelerators. This contribution reviews the development of ingot niobium technology and highlights some of the differences compared to standard FG material and opportunities for further developments.
Author :Minerals, Metals and Materials Society. Fall Meeting Publisher :Minerals, Metals, & Materials Society ISBN 13 : Total Pages :180 pages Book Rating :4.:/5 (38 download)
Book Synopsis High Temperature Niobium Alloys by : Minerals, Metals and Materials Society. Fall Meeting
Download or read book High Temperature Niobium Alloys written by Minerals, Metals and Materials Society. Fall Meeting and published by Minerals, Metals, & Materials Society. This book was released on 1991 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Reviews of Accelerator Science and Technology by : Alexander W. Chao
Download or read book Reviews of Accelerator Science and Technology written by Alexander W. Chao and published by World Scientific. This book was released on 2013-01-28 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is dedicated to superconducting technology and its applications, including superconducting magnets (SC magnets) and superconducting radio-frequency (SRF) cavities.
Book Synopsis Reviews Of Accelerator Science And Technology - Volume 5: Applications Of Superconducting Technology To Accelerators by : Alexander Wu Chao
Download or read book Reviews Of Accelerator Science And Technology - Volume 5: Applications Of Superconducting Technology To Accelerators written by Alexander Wu Chao and published by World Scientific. This book was released on 2013-01-28 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past several decades major advances in accelerators have resulted from breakthroughs in accelerator science and accelerator technology. After the introduction of a new accelerator physics concept or the implementation of a new technology, a leap in accelerator performance followed. A well-known representation of these advances is the Livingston chart, which shows an exponential growth of accelerator performance over the last seven or eight decades. One of the breakthrough accelerator technologies that support this exponential growth is superconducting technology. Recognizing this major technological advance, we dedicate Volume 5 of Reviews of Accelerator Science and Technology (RAST) to superconducting technology and its applications.Two major applications are superconducting magnets (SC magnets) and superconducting radio-frequency (SRF) cavities. SC magnets provide much higher magnetic field than their room-temperature counterparts, thus allowing accelerators to reach higher energies with comparable size as well as much reduced power consumption. SRF technology allows field energy storage for continuous wave applications and energy recovery, in addition to the advantage of tremendous power savings and better particle beam quality. In this volume, we describe both technologies and their applications. We also include discussion of the associated R&D in superconducting materials and the future prospects for these technologies.
Book Synopsis Dislocation Substructures on the Functional Properties of Niobium for SRF Cavities, Focusing on Microstructural, Microchemical, and Electromagnetic Characteristic for Florida State University by :
Download or read book Dislocation Substructures on the Functional Properties of Niobium for SRF Cavities, Focusing on Microstructural, Microchemical, and Electromagnetic Characteristic for Florida State University written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Funding is being requested pursuant to a proposal that was submitted and reviewed through the Portfolio Analysis and Management System (PAMS). PAMS Proposal ID: 222686. Superconducting cavities are the integral part of many energy-efficient particle accelerators around the world. The current material of choice for superconducting cavities is niobium, which is the material with the highest transition temperature among pure metals. The performance of SRF cavities are influenced by the fabrication and processing steps. We plan to study the microstructural, microchemical and electromagnetic properties of Nb that are processed similar to the cavity processing steps to identify and mitigate the limiting factors to improve the performance of SRF cavities.
Book Synopsis Single Crystal and Polycrystalline Niobium and OFE Copper for SRF Cavities Applications by : Jean-François Croteau
Download or read book Single Crystal and Polycrystalline Niobium and OFE Copper for SRF Cavities Applications written by Jean-François Croteau and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Manufacturing of superconducting radiofrequency (SRF) cavities with high performances is paramount to increase the collision energy in new particle accelerators. The use of high-speed sheet forming techniques, such as electro-hydraulic forming, can be beneficial, but requires a detailed understanding of the mechanical properties of the materials being deformed and the consequence on their microstructure. This thesis focuses on the characterization of high-purity niobium single crystals, polycrystalline niobium sheets, and polycrystalline OFE copper sheets. The results from this study are separated in two parts. In Part I, the characterization of niobium single crystals focused on the mechanical properties in tension and compression at strain rates of 10-4 to 103 s-1 and on the microstructure (analyzed using SEM, EBSD, TEM, and nanoindentation) of the deformed specimens. The effect of crystal orientation, strain rate, and loading direction on the mechanical properties, the crystal rotation, and the dislocation substructures are presented. In Part II, the forming limit diagram (FLD) of polycrystalline niobium sheets and OFE copper sheets were measured at a quasi-static strain rate. The FLDs of those materials should provide important data for manufacturers using conventional techniques, such as deep-drawing and spinning. The second part also presents the mechanical properties of electron beam (EB) welded polycrystalline niobium sheets and OFE copper sheets deformed in tension and compression at strain rates of 10-3 to 103 s-1.
Book Synopsis Experimental and Numerical Analysis of Hydroformed Tubular Materials for Superconducting Radio Frequency (SRF) Cavities by : Hyun Sung Kim
Download or read book Experimental and Numerical Analysis of Hydroformed Tubular Materials for Superconducting Radio Frequency (SRF) Cavities written by Hyun Sung Kim and published by . This book was released on 2016 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several conclusions can be drawn on the basis of the experimental and numerical analysis as follows: 1) The stress-strain relationship from the bulge test represents a more accurate description of the deformation behavior for a hydroforming than that from tensile tests made on segments cut from the tubular materials. 2) For anisotropic material, the incorporation of anisotropic effects using anisotropy coefficient from the tensile test led to even more accurate results. 3) A multi-scale simulation strategy using combination of continuum and CP models can give high quality predictions of the deformation under hydroforming of Cu and Nb tubes.
Book Synopsis Investigations of Residual Stresses and Mechanical Properties of Single Crystal Niobium for SRF Cavities by :
Download or read book Investigations of Residual Stresses and Mechanical Properties of Single Crystal Niobium for SRF Cavities written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work investigates properties of large grained, high purity niobium with respect to the forming of superconducting radio frequency (SRF) cavities from such large grained sheets. The yield stresses were examined using tensile specimens that were essentially single crystals in orientations evenly distributed in the standard projection triangle. No distinct yield anisotropy was found, however, vacuum annealing increased the yield strength by a factor 2.3. The deep drawing forming operation of the half cells raises the issues of elastic shape changes after the release of the forming tool (springback) and residual stresses, both of which are indicated to be negligible. This is a consequence of the low yield stress (
Book Synopsis Single Crystal - Large Grain Niobium Technology by : Ganapati Rao Myneni
Download or read book Single Crystal - Large Grain Niobium Technology written by Ganapati Rao Myneni and published by AIP Conference Proceedings / H. This book was released on 2007-08-30 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: SRF Technology based accelerators, FEL’s, and ERL’s, are becoming common worldwide. Several new frontier technologies and applications are expected to be evolving in coming years as the cost of SRF technology comes. Terra Hertz (THz) Science could benefit from these advances, and many applications are likely to be developed in the fields of medical imaging, material science, pharmaceuticals, communications etc.
Book Synopsis The Effect of Defects on Functional Properties of Niobium for Superconducting Radio-frequency Cavities by : Pulkit Garg
Download or read book The Effect of Defects on Functional Properties of Niobium for Superconducting Radio-frequency Cavities written by Pulkit Garg and published by . This book was released on 2019 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Niobium is the primary material for fabricating superconducting radio-frequency (SRF) cavities. However, presence of impurities and defects degrade the superconducting behavior of niobium twofold, first by nucleating non-superconducting phases and second by increasing the residual surface resistance of cavities. In particular, niobium absorbs hydrogen during cavity fabrication and promotes precipitation of non-superconducting niobium hydride phases. Additionally, magnetic flux trapping at defects leads to a normal conducting (non-superconducting) core which increases surface resistance and negatively affects niobium performance for superconducting applications. However, undelaying mechanisms related to hydride formation and dissolution along with defect interaction with magnetic fields is still unclear. Therefore, this dissertation aims to investigate the role of defects and impurities on functional properties of niobium for SRF cavities using first-principles methods. Here, density functional theory calculations revealed that nitrogen addition suppressed hydrogen absorption interstitially and at grain boundaries, and it also decreased the energetic stability of niobium hydride precipitates present in niobium. Further, hydrogen segregation at the screw dislocation was observed to transform the dislocation core structure and increase the barrier for screw dislocation motion. Valence charge transfer calculations displayed a strong tendency of nitrogen to accumulate charge around itself, thereby decreasing the strength of covalent bonds between niobium and hydrogen leading to a very unstable state for interstitial hydrogen and hydrides. Thus, presence of nitrogen during processing plays a critical role in controlling hydride precipitation and subsequent SRF properties. First-principles methods were further implemented to gain a theoretical perspective about the experimental observations that lattice defects are effective at trapping magnetic flux in high-purity superconducting niobium. Full-potential linear augmented plane-wave methods were used to analyze the effects of magnetic field on the superconducting state surrounding these defects. A considerable amount of trapped flux was obtained at the dislocation core and grain boundaries which can be attributed to significantly different electronic structure of defects as compared to bulk niobium. Electron redistribution at defects enhances non-paramagnetic effects that perturb superconductivity, resulting in local conditions suitable for flux trapping. Therefore, controlling accumulation or depletion of charge at the defects could mitigate these tendencies and aid in improving superconductive behavior of niobium.
