Thermal Neutron Capture Gamma-ray Spectra of the Elements


Book Description

A determination of the energy and intensity of the gamma rays resulting from thermal neutron capture in 74 natural elements is reported. The measurements include energies above 200 keV and were done with a Ge(Li) detector. (Author).







Gamma-ray Spectra Arising from Thermal-neutron Capture in Elements Found in Soils, Concretes, and Structural Materials


Book Description

Gamma-ray spectra arising from the capture of thermal neutrons are presented for iron, aluminum, copper, zinc, titanium, nickel, silicon, calcium, potassium, sodium, barium, chlorine, sulfur, and stainless steel. The spectral intensities in photons per 100 captures are presented as both individual lines and as sums of these lines over 0.5-MeV intervals which are intended for use in shielding calculations. The latter results have an estimated accuracy of plus or minus 15%, and include the contributions from both discrete and continuum gamma rays. Comparisons of these spectra are made with previously determined spectra, as well as with values reported in the Reactor Handbook, and considerable revision in the latter is concluded to be necessary. The present results do not go below 1 MeV, but when the relatively small contributions from energies less than 1 MeV are added to them, binding energy checks within plus or minus 5% are obtained. (Author).




Line and Continuum Gamma-ray Yields from Thermal-neutron Capture in 75 Elements


Book Description

The document presents the results of an analysis of thermal capture gamma-ray spectral data obtained at the MIT Thermal Capture Gamma-Ray Facility using a Ge(Li)-NaI spectrometer. This data has been previously analyzed to obtain the energies and intensities of the resolved lines from radiative neutron capture in 75 natural elements. In the present work, the spectral data was unfolded to remove the effect of the spectrometer response, and the total gamma-ray yield for both discrete lines and continuum, was determined. The method of analysis, described previously by Harper and Rasmussen, is briefly summarized. Also discussed are the binding energies producing a consistent set of values. A comparison of some of the present results with previous data is given. The capture gamma-ray energies and intensities are tabulated and the original gamma-ray spectra are shown for each element. The total gamma-ray yield data for each element has been written onto magnetic tape in the ENDF format to facilitate the use of this data by radiation transport codes. A description of the tape preparation procedure and the data formats employed are given. (Author).




Neutron Capture Gamma-Ray Spectroscopy


Book Description

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.










Remote Compositional Analysis


Book Description

Comprehensive overview of the spectroscopic, mineralogical, and geochemical techniques used in planetary remote sensing.