High-energy Neutron Spectroscopy with Activation Detectors, Incorpating New Methods for the Analysis of GE(Li) Gamma-ray Spectra and the Solution of Fredholm Integral Equations PDF Download

Author: Jorma Tapio Routti
Publisher:
ISBN:
Category :
Languages : en
Pages : 155

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Author: Jorma Tapio Routti
Publisher:
ISBN:
Category :
Languages : en
Pages : 310

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Author: Norman C. Rasmussen
Publisher:
ISBN:
Category : Gamma ray spectrometry
Languages : en
Pages : 171

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The objectives of this contract were to carry out basic research in the areas of neutron spectroscopy and dosimetry, gamma-ray spectroscopy and dosimetry, and activation analysis techniques. Early work in gamma-ray spectroscopy was done mostly with the bent crystal spectrometers and the triple coincidence scintillation spectrometer which were used in capture gamma-ray studies. Later, however, all the work in gamma-ray spectroscopy was in the development and application of lithium drifted Ge(Li) solid state detectors. A description is included of the fabrication techniques used and the application of these detectors to the study of capture gamma-rays and spent reactor fuel. Work on problems of neutron spectroscopy and dosimetry are described. This work resulted in an improved method for measuring fast neutron spectra through the use of foils. The work done in activation analysis is summarized.

Author: G. Molnar
Publisher: Springer Science & Business Media
ISBN: 0387233598
Category : Science
Languages : en
Pages : 448

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Prompt gamma activation analysis (PGAA) is a unique, non-destructive nuclear analytical method with multi-element capabilities. It is most effective if intense neutron beams (especially cold beams) of nuclear reactors are used to induce the prompt gamma radiation. Based largely on the authors' pioneering research in cold neutron PGAA, the handbook describes the methodology in self-contained manner and reviews recent applications. The library of prompt gamma ray data and spectra for all natural elements is a unique aid to the practitioner. The level is understandable by a broad audience, which facilitates teaching and training. The Handbook of Prompt Gamma Activation Analysis is a comprehensive handbook written for those practising the method, wanting to implement it at a reactor facility, or just looking for a powerful non-destructive method of element analysis. The book is also useful for nuclear physics, chemistry and engineering scientists, scholars and graduate students interested in neutron-induced gamma ray spectroscopy and nuclear analytical methods.

Author: James Duncan Hall
Publisher:
ISBN:
Category : Gamma ray spectrometry
Languages : en
Pages : 36

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A neutron-gamma ray spectrometer developed at Texas Nuclear Corporation is described. The spectrometer employs pulse shape discrimination in an organic scintillator detector to selectively detect neutrons or gamma rays in a mixed field by a method not utilizing space charge limiting. Selective detection may be obtained for neutrons of energy higher than 0.7 MeV and for gamma rays above 0.25 MeV. Spectral information is usable to 15 MeV for neutrons and to 4 MeV for gamma rays. Detection efficiencies range from about 6% to 30%. Typical spectra, data analysis procedure, and operating characteristics of the spectrometer are presented.

Author: R. E. Chrien
Publisher: Springer Science & Business Media
ISBN: 146132940X
Category : Science
Languages : en
Pages : 875

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The post World War II era witnessed a tremendous growth in the research carried out in neutron-induced reactions and especially in neutron capture y-ray studies. This growth was stimulated by the availability of neutron sources, such as reactors and accelerators, and by the development of high resolution y-ray and conversion electron detectors. Today the combination of high flux reactors and precise instrumentation has produced spectral data of exceptional quality, as the pages of these proceedings illustrate. The world-wide community of the practioners of the art of cap ture y-ray spectroscopy has met three times in the last decade: the first international symposium on this subject was held at Studsvik, Sweden in 1969, and the second at Petten, The Netherlands in 1974. A smaller meeting, of mostly u. S. and some European parti cipation, was held at Argonne National Laboratory in 1966. A perusal of the proceedings of these meetings shows the striking ad vances in this now mature field of physics over the last dozen years. Each meeting has seen a small but perceptible increase in the number of papers presented and the number of laboratories repre sented. More importantly, each meeting has documented the increasing impact of (n,y) reasearch, not only on other areas of basic physics, but also on commercial and medical applications of this technology. A total of 29 invited papers and 97 contributed papers were presented at this symposium.

Author:
Publisher:
ISBN:
Category : Neutron capture gamma ray spectroscopy
Languages : en
Pages : 728

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Author: Oyinkansola Modupe Ajayi
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Neutron-induced spectroscopy measurements are commonly used to quantify in-situ elemental and mineral compositions of rocks from the processing of measured gamma-ray energy spectra. However, geometrical effects on measured spectroscopy logs, such as thin beds, dipping beds, and deviated well trajectories, can cause shoulder-bed averaging that compromises the assessment of true layer elemental and mineral compositions. Traditional methods of interpreting neutron-induced gamma-ray spectroscopy measurements typically neglect such shoulder-bed averaging effects in the estimation of elemental and mineral compositions. Monte Carlo methods accurately reproduce borehole and formation geometrical effects on spectroscopy measurements but are extremely time consuming and impractical for use in routine interpretation. Reliable measurement interpretation must therefore begin with the development of a fast and accurate forward simulation method that explicitly incorporates measurement physics, borehole, tool, and formation geometry. This dissertation introduces a new algorithm to rapidly simulate elemental and mineral compositions from neutron induced spectroscopy measurements. The algorithm utilizes neutron-gamma ray spatial sensitivity functions to account for environmental and three-dimensional (3D) effects of formation porosity, fluids, dipping beds, thin beds, and arbitrary well trajectories. Simulations assume a logging-while-drilling (LWD) spectroscopy tool furbished with a 14-MeV pulsed-neutron source in the interpretation of gamma ray spectra obtained from high energy inelastic neutron scattering and thermal neutron capture. Results obtained with the rapid simulation method are benchmarked against rigorous Monte Carlo spectroscopy calculations for synthetic conventional and unconventional thinly-bedded reservoirs penetrated by vertical and high angle/horizontal (HA/HZ) wells. The fast simulation method yields calculations in approximately 1e6 the time required by Monte Carlo simulations, with an average difference below 5% between Monte Carlo and fast simulated logs. An inversion-based interpretation method is next introduced to accurately evaluate mineral concentrations from measured spectroscopy elemental logs based on the analytical relationship between elements and minerals through their chemical formulas. In the presence of geometrical effects, spectroscopy elemental and mineral logs are corrected for shoulder-bed averaging by the inclusion of spatial sensitivity maps, which account for such geometrical effects, in the inversion-based interpretation. Calculations are performed with both inelastic and capture gamma-ray spectroscopy measurements which arise from high-energy inelastic neutron scattering and low-energy thermal neutron capture, respectively. This strategy provides two sets of data that can ascertain chemical elements or minerals detectable in only one measurement mode and also independently validates estimated elemental and mineral compositions. In laminated formations, where layer thicknesses are below the vertical resolution of the tool, it is impossible to quantify layer properties with inversion methods. An additional interpretation method based on a new spectroscopy mixing law is therefore developed to estimate elemental and mineral compositions within individual laminae. The new inversion-based interpretation methods are successfully implemented in diverse synthetic and field cases with varying lithology types and well trajectories including vertical and HA/HZ wells. Results show that the developed methods reduce shoulder-bed averaging effects on measured spectroscopy logs by as much as 0.4 yield fraction, 0.17 weight fraction, and 0.34 mineral volume fraction. Finally, a new spectroscopy-based petrophysical interpretation method is introduced that utilizes estimated mineralogy to overcome the common assumption of homogeneous lithology in measured porosity logs, thereby improving the estimation of porosity and water saturation. Inclusion of shoulder-bed averaging effects on spectroscopy mineral logs also increases the accuracy of spectroscopy-based petrophysical interpretation.

Author: Thomas L. Isenhour
Publisher:
ISBN:
Category : Gamma ray spectrometry
Languages : en
Pages : 212

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Author: Fay Ajzenberg-Selove
Publisher: Academic Press
ISBN: 1483275809
Category : Science
Languages : en
Pages : 644

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Nuclear Spectroscopy, Part A deals with the experimental and theoretical techniques involved in nuclear spectroscopy. This book discusses the interactions of charged particles with matter, gaseous ionization detectors, and particular mass attenuation coefficients. The magnetic gamma-ray spectrometers for photo or internal-conversion electrons, general characteristics of cross-section variation with energy, and measurement of fast neutron spectra are also elaborated. This text likewise covers the elastic scattering of photons by nuclei and measurement of widths of gamma-radiating levels. This publication is recommended for graduate students preparing for experimental research in nuclear spectroscopy, students who have completed graduate-level courses in quantum mechanics and nuclear physics, and specialists who wish to acquire a broader understanding of nuclear spectroscopy.