Neutron-induced prompt gamma activation analysis (PGAA) of metals and non-metals in ocean floor geothermal vent-generated samples

AIP Conference Proceedings

Molnár

Révay

et al. 2006

Self Cite

Abstract. The Evaluated Gamma-ray Activation File (EGAF), a new database of prompt and delayed neutron capture γ ray cross sections, has been prepared as part of an International Atomic Energy Agency (IAEA) Coordinated Research Project to develop a "Database of Prompt Gamma-rays from Slow Neutron Capture for Elemental Analysis". Recent elemental γ-ray cross-section measurements performed with the guided neutron beam at the Budapest Reactor have been combined with data from the literature to produce the EGAF database. EGAF contains thermal cross sections for ≈35,000 prompt and delayed γ-rays from 262 isotopes. New precise total thermal radiative cross sections have been derived for many isotopes from the primary and secondary gamma-ray cross sections and additional level scheme data. An IAEA TECDOC describing the EGAF evaluation and tabulating the most prominent γ-rays will be published in 2004. The TECDOC will include a CD-ROM containing the EGAF database in both ENSDF and tabular formats with an interactive viewer for searching and displaying the data.

“…Notable examples include the analysis of deep sea vent [18] and reagent materials [19]. Total radiative cross sections were determined for most isotopes [8,20].…”

Section: Applications Of the Egaf Databasementioning

confidence: 99%

The Evaluated Gamma-ray Activation File (EGAF)

AIP Conference Proceedings

Molnár

Révay

et al. 2006

Self Cite

“…The focus of the LBNL PGAA research to date (5,6,7) has been to determine the requirements for producing high-quality (i.e., accurate and precise) qualitative and quantitative results for in-situ, non-5 destructive assay of legacy materials. Since much of the LBNL legacy inventory consists of radioactivity incorporated into a stable carrier matrix, initial experiments were configured to test the utility of PGAA to account for all entrained carrier species and to determine if chemical stoichiometry may be deduced.…”

Section: Resultsmentioning

confidence: 99%

Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials

English

Perry

et al. 2008

J Radioanal Nucl Chem

Self Cite

Without quality historical records that provide the compositions of legacy materials, the elemental and/or chemical characterization of such materials requires a manual analytical strategy that may expose the analyst to unknown toxicological hazards. In addition, much of the existing legacy inventory also incorporates radioactivity, and, although radiological composition may be determined by various nuclearanalytical methods, most importantly, gamma spectroscopy, current methods of chemical characterization still require direct sample manipulation, thereby presenting special problems with broad implications for both the analyst and the environment. Alternately, Prompt Gamma Activation Analysis (PGAA) provides a 'single-shot', in-situ, non-destructive method that provides a complete assay of all major entrained elemental constituents. Also, it generally obviates the need for sample handling and, thus, minimizes potential exposure to hazardous materials to both people and the environment. Additionally, neutron activation analysis (NAA) using short-lived activation products compliments PGAA, and is especially applicable when the NAA activation surpasses the PGAA in elemental sensitivity. The Lawrence Berkeley National Laboratory (LBNL) has developed a new miniature deuterium-deuterium (D+D) neutron generator that currently outputs ~ 4x10 9 neutrons/second. It is self-replenishing and low power and maximizes the use of monatomic D + ions that, in turn, maximizes neutron intensity. The LBNL PGAA system also uses a recently updated prompt gamma library database and Hypermet software to convert the raw PGAA spectral data to accurate and precise qualitative and quantitative elemental results. This paper 2 discusses the use of PGAA and short-lived NAA to characterize legacy materials at the Lawrence Berkeley National Laboratory (LBNL). IntroductionMuch of the legacy inventory at LBNL lacks quality historical records that satisfy the pertinent regulatory requirements for full characterization. Most of the inventoried materials also include one or more radioactive constituents, typically actinides, adding another dimension to the overall problem. The radioanalytical problem may generally be addressed by gamma spectroscopy. However, except for the primordial radioactivities with extremely long half-lives like U and Th, the presence of a visible mass of material is not generally attributable to the radioactive constituents but, instead, to the presence of stable carrier chemicals that must likewise be characterized. In the special case of the actinides, one may glean some information about the cationic moiety of the carrier substrate by alpha-induced x-ray fluorescence since most carrier compounds at LBNL have cationic entities of relatively high Z, thereby affording easier detection and evaluation of the fluorescence x-rays. However, for the anionic moiety, the respective Z values are usually much lower (e.g., fluorides, nitrates, oxides) and not generally amenable to fluorescence analysis. Therefore, to characterize stable...

“…[15][16][17] The compounds of beryllium, magnesium, scandium, antimony, gallium, lead, thorium, and uranium were obtained commercially as being reagent grade.…”

Section: Methodsmentioning

confidence: 99%

“…[15][16][17] The Budapest Reactor is a water-cooled, water-moderated research reactor with a thermal power of 10 MW. A beam of lowenergy neutrons is transported for approximately 35 meters from the reactor core by a curved neutron guide fabricated from a glass coat with a nickel reflector.…”

Section: Pgaa Methodsmentioning

confidence: 99%

Analyses of oxyanion materials by prompt gamma activation analysis

Perry

English

et al. 2007

J Radioanal Nucl Chem

Self Cite

Prompt gamma activation analysis (PGAA) has been used to analyze metal ion oxyanion materials that have multiple applications, including medicine, materials, catalysts, and electronics. The significance for the need for accurate, highly sensitive analyses for the materials is discussed in the context of quality control of end products containing the parent element in each material. Applications of the analytical data for input to models and theoretical calculations related to the electronic and other properties of the materials are discussed. IntroductionElemental analyses for a wide array of elements in the Periodic Table are of extreme value for a wide range of purposes, including trying to gain a knowledge of materials failure when it occurs, modeling the electronic, magnetic, and chemical properties, and assessing and verifying quality control of the purity of the materials in which they are found. Both the elements and their compounds are useful for an extremely wide variety of applications in chemistry and materials science, including applications that are dependent on the elements' magnetic, electronic, and physical properties as well as their ability to form compounds and complexes. In obtaining precise analytical data for materials, the analyst may need a technique which will give really good, high-quality analytical data while preserving the integrity of the samples for archival purposes.The materials that have been analyzed in the present study represent an eclectic group of elements that are important from a wide number of standpoints. Additionally, in many cases, the counteranions associated with the central elements in the materials can be of extreme importance in the compound's role as synthetic precursors for other materials where the original materials or compounds have really good advantages as starting materials. Beryllium nitrate, for example, can be used as a starting material for the synthesis of beryllium oxide, 1 which is used in an extremely wide variety of applications ranging from sophisticated electronic materials 2 to dopants in gemstones 3 to dental materials. 4 It also represents, however, an element whose toxicity in humans 5,6 makes it extremely important as an analytical target due to many applications that impact both humans and the environment. Magnesium sulfate is widely used in medical and biomedical applications, 7 while scandium and its compounds (including the sulfate analyzed here) act as precursors in the synthesis of materials as well as serve as materials on their own. 8 Antimony is used in a wide variety of applications employing mixed elemental oxides, including catalysts, alloys, and magnetic materials. 9 Gallium is used for a wide assortment of electronic materials such as gallium arsenide, 10 many of which demand extremely high purity and quality control. Lead has applications in materials including powders, electronic devices, and ceramics 11 and also an extensive biochemistry and toxicology, 12 all areas of interest areas necessitating the ability to obtain de...