physical processes in inorganic scintillators

However, compared with Ce:GPS, the Pr:LuAG scintillator has a relatively low light yield and possesses intrinsic radioactivity and short peak emission wavelength (306 nm). The light yield of Pr:LuAG, another scintillator known to have excellent temperature resistance, shows only slightly lower light output at 225 ☌ than at 50 ☌. The light yield of Ce:GPS was almost consistent from RT up to approximately 250 ☌. The Ce:GPS scintillator was first introduced in 2007 and is known to have excellent energy resolution, light yield, and temperature dependence. Some of the newly developed oxide scintillators have demonstrated potentials to be used in the well-logging industry. Thus, these two scintillators can replace NaI:Tl scintillator in well-logging, considering that they both have a similar drawback as NaI:Tl of being extremely sensitive to humidity and being very brittle. For example, LaCl 3:Ce maintains an almost constant light yield from 100 to 600 K, reaching its maximum at 500 K. Along with LaBr 3:Ce, 10% doped LaCl 3 showed even more impressive scintillation characteristics over a wide range of temperatures. Regarding temperature resistance, LaBr 3:Ce was reported to show 8% energy resolution at 175 ☌, superior to the 9.9% energy resolution of NaI:Tl at RT. These halide scintillators have received huge attention due to their excellent properties such as excellent light yield, good energy resolution, and high density. The increasing desire for more efficient high-temperature-resistant scintillators has led to the discovery of new halide scintillators, such as LaBr 3:Ce and LaCl 3:Ce, which were first introduced in the early 2000s. In addition, radiation detectors have to operate at high levels of vibration and shock, so the brittleness of the scintillator should also be considered. Therefore, radiation detectors used in the well-logging industry must maintain their performance in terms of scintillation properties (such as emission spectrum, decay time, and light output) at high temperatures. In general, the downhole environment is known to be at a temperature of about 175 ☌ and a pressure of 20,000 psi, and the vibration level and shock level caused by drilling are ~30 g RMS and ~700 g, respectively. Furthermore, in the case of logging while drilling implementations, the radiation detector may experience high levels of vibration and shock. The deeper the well, the harsher the downhole environment (temperature) in which nuclear measurements need to be made. Throughout, the author does not offer complicated derivations of equations but, instead, presents useful equations with practical results.For decades, there has been a steady demand for high-temperature radiation detectors to be used in the well-logging industry, and oil wells need to be drilled deeper to access new fuel sources. The section on the role of defects in energy transfer and scintillation efficiency will be of special interest. The book then discusses the complicated mechanisms of energy conversion and transformation in inorganic scintillators. This unique work first defines the fundamental physical processes underlying scintillation and governing the primary scintillation characteristics of light output, decay time, emission spectrum, and radiation hardness.

Now, a world leader in the theory and applications of scintillation processes integrates the latest scientific advances of scintillation into a new work, 'Physical Processes in Inorganic Scintillators'.Written by distinguished researcher Piotr Rodnyi, this volume explores this challenging subject, explains the complexities of scintillation from a modern point of view, and illuminates the way to the development of better scintillation materials. However, until now there have been no books available that address in detail the complex scintillation processes associated with these new developments. Demand continues for new and improved scintillation materials for a variety of applications including nuclear and high energy physics, astrophysics, medical imaging, geophysical exploration, radiation detection, and many other fields. New scintillation materials have been investigated, novel scintillation mechanisms have been discovered, and additional scintillator applications have appeared. During the last ten to fifteen years, researchers have made considerable progress in the study of inorganic scintillators.

Physical processes in inorganic scintillators