Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Characterization of Cerium Fluoride Nanocomposite Scintillators
Author: Synthesis and Characterization of Nanocomposite Scintillators for Radiation Detection
Author: Sunil Kumar SahiPublisher:
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.
Development of Cerium Fluoride Nanocomposites for Neutron Capture Measurements
Author: Nanocomposite, Ceramic, and Thin Film Scintillators
Author: Martin NiklPublisher: 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.
Engineering of Scintillation Materials and Radiation Technologies
Author: Mikhail KorzhikPublisher: 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.
Cerium Fluoride, a New Fast, Heavy Scintillator
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
We describe the scintillation properties of Cerium Fluoride (CeF3), a newly discovered, heavy (6.16 g/cm3), inorganic scintillator. Its fluorescence decay lifetime, measured with the delayed coincidence method, is described by a single exponential with a 27 /+-/ ns time constant. The emission spectrum peaks at a wavelength of 340 nm, and drops to less than 10% of its peak value at 315 nm and 460 nm. When a 1 cm optical quality cube of CeF3 is excited with 511 keV photons, a photopeak with a 20% full width at half maximum is observed at approximately half the light output of a Bismuth Germanate (BGO) crystal with similar geometry. We also present measurements of the decay time and light output of CeF3 doped with three rare-earth elements (Dy, Er, and Pr). The short fluorescence lifetime, high density, and reasonable light output of this new scintillator suggest that it would be useful for applications where high counting rates, good stopping power, and nanosecond timing are important, such as medical imaging and nuclear science. 5 refs., 6 figs., 1 tab.
Cerium Fluoride, a Highly Radiation-resistive Scintillator
Author: M. KobayashiNanocomposite Glass-ceramic Scintillators for Radiation Spectroscopy
Author: Meredith Brooke BartaPublisher:
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.
Divalent Fluoride Doped Cerium Fluoride Scintillator
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The use of divalent fluoride dopants in scintillator materials comprising cerium fluoride is disclosed. The preferred divalent fluoride dopants are calcium fluoride, strontium fluoride, and barium fluoride. The preferred amount of divalent fluoride dopant is less than about two percent by weight of the total scintillator. Cerium fluoride scintillator crystals grown with the addition of a divalent fluoride have exhibited better transmissions and higher light outputs than crystals grown without the addition of such dopants. These scintillators are useful in radiation detection and monitoring applications, and are particularly well suited for high-rate applications such as positron emission tomography (PET).
Nanocomposite Scintillator, Detector, and Method
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A compact includes a mixture of a solid binder and at least one nanopowder phosphor chosen from yttrium oxide, yttrium tantalate, barium fluoride, cesium fluoride, bismuth germanate, zinc gallate, calcium magnesium pyrosilicate, calcium molybdate, calcium chlorovanadate, barium titanium pyrophosphate, a metal tungstate, a cerium doped nanophosphor, a bismuth doped nanophosphor, a lead doped nanophosphor, a thallium doped sodium iodide, a doped cesium iodide, a rare earth doped pyrosilicate, or a lanthanide halide. The compact can be used in a radiation detector for detecting ionizing radiation.