Author: Meredith Brooke Barta Publisher: ISBN: Category : Gamma ray detectors Languages : en Pages :
Book Description
In recent years, the United States Departments of Homeland Security (DHS) and Customs and Border Protection (CBP) have been charged with the task of scanning every cargo container crossing domestic borders for illicit radioactive material. This is accomplished by using gamma-ray detection systems capable of discriminating between non-threatening radioisotopes, such as Cs-137, which is often used in nuclear medicine, and fissile material, such as U-238, that can be used to make nuclear weapons or "dirty" bombs. Scintillation detector systems, specifically thallium-doped sodium iodide (NaI(Tl)) single crystals, are by far the most popular choice for this purpose because they are inexpensive relative to other types of detectors, but are still able to identify isotopes with reasonable accuracy. However, increased demand for these systems has served as a catalyst for the research and development of new scintillator materials with potential to surpass NaI(Tl). The focus of a majority of recent scintillator materials research has centered on sintered transparent ceramics, phosphor-doped organic matrices, and the development of novel single crystal compositions. Some of the most promising new materials are glass-ceramic nanocomposites. By precipitating a dense array of nano-scale scintillating crystals rather than growing a single monolith, novel compositions such as LaBr3(Ce) may be fabricated to useful sizes, and their potential to supersede the energy resolution of NaI(Tl) can be fully explored. Also, because glass-ceramic synthesis begins by casting a homogeneous glass melt, a broad range of geometries beyond the ubiquitous cylinder can be fabricated and characterized. Finally, the glass matrix ensures environmental isolation of the hygroscopic scintillating crystals, and so glass-ceramic scintillators show potential to serve as viable detectors in alpha- and neutron-spectroscopy in addition to gamma-rays. However, for the improvements promised by glass-ceramics to become reality, several material properties must be considered. These include the degree of control over precipitated crystallite size, the solubility limit of the glass matrix with respect to the scintillating compounds, the variation in maximum achievable light yield with composition, and the peak wavelength of emitted photons. Studies will focus on three base glass systems, sodium-aluminosilicate (NAS), sodium-borosilicate (NBS), and alumino-borosilicate (ABS), into which a cerium-doped gadolinium bromide (GdBr3(Ce)) scintillating phase will be incorporated. Scintillator volumes of 50 cubic centimeters or greater will be fabricated to facilitate comparison with NaI(Tl) crystals currently available.
Author: Martin Nikl Publisher: CRC Press ISBN: 1315340976 Category : Science Languages : en Pages : 361
Book Description
The literature so far has reviewed only single-crystal and, up to some extent, optical ceramic scintillators. This book introduces and describes in detail the research and development in thin film scintillators, glass ceramics, as well as nanocomposite and optical ceramics prepared by spark plasma sintering. It also features example of an in-depth study of a ZnO-based powder phosphor material. Both technology description and various characterization aspects are provided together with application hints. No other book has been published so far that includes and reviews the scintillator materials covered in this book with their specific technologies. Moreover, technological description is merged with detailed characterization, and the application potential is discussed as well. This book is intended for a wide audience, including postgraduate and PhD students and scientists working in the field of scintillators and phosphors. The extended introductory text, which has a textbook character, will be of immense benefit to students and non-specialists, too.
Author: Martin Nikl Publisher: CRC Press ISBN: 9814745235 Category : Science Languages : en Pages : 351
Book Description
The literature so far has reviewed only single-crystal and, up to some extent, optical ceramic scintillators. This book introduces and describes in detail the research and development in thin film scintillators, glass ceramics, as well as nanocomposite and optical ceramics prepared by spark plasma sintering. It also features example of an in-depth study of a ZnO-based powder phosphor material. Both technology description and various characterization aspects are provided together with application hints. No other book has been published so far that includes and reviews the scintillator materials covered in this book with their specific technologies. Moreover, technological description is merged with detailed characterization, and the application potential is discussed as well. This book is intended for a wide audience, including postgraduate and PhD students and scientists working in the field of scintillators and phosphors. The extended introductory text, which has a textbook character, will be of immense benefit to students and non-specialists, too.
Author: Sunil Kumar Sahi Publisher: ISBN: Category : Nanocomposites (Materials) Languages : en Pages : 163
Book Description
Inorganic single crystal and organic (plastic and liquid) scintillators are commonly used for radiation detection. Inorganic single crystals are efficient and have better energy resolution compared to organic scintillators. However, inorganic single crystals are difficult to grow in large size and hence expensive. On the other hand, fast decay time and ease of fabrication makes organic scintillators attractive for many applications. However, poor energy resolution of organic scintillators limits its applications in gamma ray spectroscopy. The poor energy resolution is due to the low Z-Value and low density of organic scintillator. The Z-value of organic plastic scintillator can be increase by loading nanoparticles in plastic matrix. It is expected that the increase in Z-value would result in improve energy resolution of nanocomposite scintillator. However, the loss of optical transparency due to nanoparticles loading is one of the major concerns of nanocomposite scintillators. In this dissertation, we used different methods to synthesize LaxCe1-xF3 nanoparticles with high dispersion in polymer matrix. High nanoparticle dispersion is important to load high concentration of nanoparticles into polymer matrix without losing the transparency of the polymer matrix. The as synthesized nanoparticles are dispersed into monomers and polymerized using heat initiated bulk polymerization method. Nanoparticles are characterized using TEM, XRD, FTIR and TGA. The optical and scintillation properties of nanoparticles and nanocomposites are studied using spectroscopic techniques. The pulse height spectra obtained using nanocomposite fabricated by loading up to 30 wt% nanoparticles clearly show a photopeak for the 122 keV line of the Co-57 isotope. The generation of the photopeak is due to the enhanced photoelectric effect as a result of increased effective atomic number (Zeff) and density of nanocomposite scintillator. The pulse height spectra of Cs-137 gamma source show a full energy peak at around 622 keV, due to the escape of La and Ce K[alpha] X-rays. The fabrication process of transparent nanocomposite scintillator is discussed in details.
Author: Mikhail Korzhik Publisher: Springer ISBN: 3319684655 Category : Science Languages : en Pages : 346
Book Description
This volume provides a broad overview of the latest achievements in scintillator development, from theory to applications, and aiming for a deeper understanding of fundamental processes, as well as the discovery and availability of components for the production of new generations of scintillation materials. It includes papers on the microtheory of scintillation and the initial phase of luminescence development, applications of the various materials, and development and characterization of ionizing radiation detection equipment. The book also touches upon the increased demand for cryogenic scintillators, the renaissance of garnet materials for scintillator applications, nano-structuring in scintillator development, development and applications for security, and exploration of hydrocarbons and ecological monitoring.
Author: Adrian Goldstein Publisher: John Wiley & Sons ISBN: 1119429552 Category : Technology & Engineering Languages : en Pages : 852
Book Description
A detailed account of various applications and uses of transparent ceramics and the future of the industry In Transparent Ceramics: Materials, Engineering, and Applications, readers will discover the necessary foundation for understanding transparent ceramics (TCs) and the technical and economic factors that determine the overall worth of TCs. This book provides readers with a thorough history of TCs, as well as a detailed account of the materials, engineering and applications of TC in its various forms; fabrication and characterization specifics are also described. With this book, researchers, engineers, and students find a definitive guide to past and present use cases, and a glimpse into the future of TC materials. The book covers a variety of TC topics, including: ● The methods employed for materials produced in a transparent state ● Detailed applications of TCs for use in lasers, IR domes, armor-windows, and various medical prosthetics ● A review of traditionally used transparent materials that highlights the benefits of TCs ● Theoretical science and engineering theories presented in correlation with learned data ● A look at past, present, and future use-cases of TCs This insightful guide to ceramics that can be fabricated into bulk transparent parts will serve as a must-read for professionals in the industry, as well as students looking to gain a more thorough understanding of the field.
Author: J. David Musgraves Publisher: Springer Nature ISBN: 3319937286 Category : Technology & Engineering Languages : en Pages : 1851
Book Description
This handbook provides comprehensive treatment of the current state of glass science from the leading experts in the field. Opening with an enlightening contribution on the history of glass, the volume is then divided into eight parts. The first part covers fundamental properties, from the current understanding of the thermodynamics of the amorphous state, kinetics, and linear and nonlinear optical properties through colors, photosensitivity, and chemical durability. The second part provides dedicated chapters on each individual glass type, covering traditional systems like silicates and other oxide systems, as well as novel hybrid amorphous materials and spin glasses. The third part features detailed descriptions of modern characterization techniques for understanding this complex state of matter. The fourth part covers modeling, from first-principles calculations through molecular dynamics simulations, and statistical modeling. The fifth part presents a range of laboratory and industrial glass processing methods. The remaining parts cover a wide and representative range of applications areas from optics and photonics through environment, energy, architecture, and sensing. Written by the leading international experts in the field, the Springer Handbook of Glass represents an invaluable resource for graduate students through academic and industry researchers working in photonics, optoelectronics, materials science, energy, architecture, and more.
Author: Gurpreet Singh Publisher: John Wiley & Sons ISBN: 1119324637 Category : Technology & Engineering Languages : en Pages : 402
Book Description
This proceedings volume contains a collection of 34 papers from the following symposia held during the 2015 Materials Science and Technology (MS&T '15) meeting: Innovative Processing and Synthesis of Ceramics, Glasses and Composites Advances in Ceramic Matrix Composites Advanced Materials for Harsh Environments Advances in Dielectric Materials and Electronic Devices Controlled Synthesis, Processing, and Applications of Structure and Functional Nanomaterials Processing and Performance of Materials Using Microwaves, Electric and Magnetic Fields, Ultrasound, Lasers, and Mechanical Work, Rustum Roy Memorial Symposium Sintering and Related Powder Processing Science and Technologies Surface Protection for Enhanced Materials Performance: Science, Technology, and Application Thermal Protection Materials and Systems Ceramic Optical Materials Alumina at the Forefront of Technology
Author: Paul Lecoq Publisher: Springer ISBN: 3319455222 Category : Science Languages : en Pages : 420
Book Description
This second edition features new chapters highlighting advances in our understanding of the behavior and properties of scintillators, and the discovery of new families of materials with light yield and excellent energy resolution very close to the theoretical limit. The book focuses on the discovery of next-generation scintillation materials and on a deeper understanding of fundamental processes. Such novel materials with high light yield as well as significant advances in crystal engineering offer exciting new perspectives. Most promising is the application of scintillators for precise time tagging of events, at the level of 100 ps or higher, heralding a new era in medical applications and particle physics. Since the discovery of the Higgs Boson with a clear signature in the lead tungstate scintillating blocks of the CMS Electromagnetic Calorimeter detector, the current trend in particle physics is toward very high luminosity colliders, in which timing performance will ultimately be essential to mitigating pile-up problems. New and extremely fast light production mechanisms based on Hot-Intraband-Luminescence as well as quantum confinement are exploited for this purpose. Breakthroughs such as crystal engineering by means of co-doping procedures and selection of cations with small nuclear fragmentation cross-sections will also pave the way for the development of more advanced and radiation-hard materials. Similar innovations are expected in medical imaging, nuclear physics ecology, homeland security, space instrumentation and industrial applications. This second edition also reviews modern trends in our understanding and the engineering of scintillation materials. Readers will find new and updated references and information, as well as new concepts and inspirations to implement in their own research and engineering endeavors.
Author: Hao Yu Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Fast scintillators with spectroscopic gamma response are essential in nuclear security and medical imaging. However, few individual scintillation materials exhibit both fast scintillation decay and excellent photopeak energy resolution. This dissertation strives to develop organic scintillators for fast spectroscopic gamma detection. The focus is to load high-Z nanoparticles (NPs) into plastics and liquids. A nanocomposite plastic scintillator comprising 40 wt% hafnium oxide nanoparticles uniformly dispersed in a luminescent plastic matrix is synthesized. The nanoparticles have an average diameter of 4.2 nm and are covalently attached to the polymer matrix to prevent agglomeration. A progressive curing protocol using a low-temperature and a high-temperature initiator is developed to synthesize centimeter-size nanocomposites. The addition of 5 vol% divinylbenzene is key to boosting bulk transmittance, resulting in a measured transmittance of around 80% across the emission range. Gamma pulse scintillation has a fast decay time constant of 2.5 ns and a modest light output of 8,000-9,000 photons/MeV. The gamma scintillation shows energy proportionality from 32 to 1275 keV. A 1.93 cm3 nanocomposite produces photopeaks at 32 and 662 keV for 137Csand at 511 and 1275 keV for 22Na. The photopeak energy resolution at 662 keV is 7.2%-9.1%. While the energy resolution is approaching that of single crystal scintillators, it is negatively impacted by the trade-off between high NP loading and diminishing light output. To address this issue, CsPbBr3 quantum dots (QDs) are loaded into liquid scintillators up to 40 wt%. Pyrromethene 580 (PM-580), a fluorescent dye, is co-dissolved in the solution as a fluorescence resonance energy transfer acceptor to overcome the self-absorption of the QDs. The rapid energy transfer from the QDs to PM-580 also accelerates the scintillation decay kinetics. The decay time constant is 24.3 ns, faster than most inorganic crystal scintillators. The light output is 7,300 photons/MeV at 40 wt% QD loading. Gamma pulse spectroscopy of the 40 wt% QD liquid produces a 662 keV gamma photopeak with a 27% energy resolution, demonstrating the potential of the CsPbBr3 QD loaded organic scintillators for spectroscopic gamma detection.
Author: Meredith Brooke Barta
Author: Martin Nikl
Author: Martin Nikl
Author: Sunil Kumar Sahi
Author: Mikhail Korzhik
Author: Adrian Goldstein
Author: J. David Musgraves
Author: Gurpreet Singh
Author: Paul Lecoq
Author: Hao Yu