Download or read book Improved Isotopic Measurement of Plutonium by Thermal Ionization Mass Spectrometry written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal ionization mass spectrometry (TIMS) is accepted widely as the benchmark method for precise and accurate isotopic determination of plutonium. TIMS is one of the few analytical methods capable of determining Pu in bioassay samples at the level required for detecting a 50 yr committed dose of 100 mRem resulting from an inhalation exposure to highly insoluble forms of Pu. Typically, Pu is measured in bioassay samples by radiochemical separation, electrodeposition onto a planchet, and radiometric determination by alpha spectrometry. If, based on the alpha spectrometry results, a sample is deemed to need a more sensitive analysis (i.e. suspected uptake, borderline alpha spectrometry positive for Pu uptake, etc.), then the sample is prepared for analysis by TIMS. Part of the development process for establishing a program to determine Pu in bioassay samples by TIMS at the Savannah River Site involved a careful evaluation of the Pu blank value in the reagents used for sample preparation and in urine blanks. This exercise allowed for the evaluation of the newly developed radiochemical separation procedure, the resin bead loading procedure, and the detection limits of the thermal ionization mass spectrometer.
Download or read book Improved Sample Utilization in Thermal Ionization Mass Spectrometry Isotope Ratio Measurements written by Matthew Louis Baruzzini and published by . This book was released on 2017 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The precise and accurate determination of isotopic composition in nuclear forensic samples is vital for assessing origin, intended use and process history. Thermal ionization mass spectrometry (TIMS) is widely accepted as the gold standard for high performance isotopic measurements and has long served as the workhorse in the isotopic ratio determination of nuclear materials. Nuclear forensic and safeguard specialists have relied heavily on such methods for both routine and atypical efforts. Despite widespread use, TIMS methods for the assay of actinide systems continue to be hindered by poor ionization efficiency, often less than tenths of a percent; the majority of a sample is not measured. This represents a growing challenge in addressing next-generation nuclear detection needs by limiting the ability to analyze ultra-trace quantities of high priority elements that could potentially provide critical nuclear forensic signatures. Porous ion emitter (PIE) thermal ion sources were developed in response to the growing need for new TIMS ion source technologies. By simultaneously incorporating multiple, previously developed strategies for improved ionization efficiency, PIEs have proven to be simple to implement, straightforward approach to boosting ion yield. This work serves to expand the use of PIE techniques for the analysis of trace quantities of plutonium and americium. PIEs exhibited superior plutonium and americium ion yields when compared to direct filament loading and the resin bead technique, one of the most efficient methods for actinide analysis, at similar mass loading levels. Initial attempts at altering PIE composition for the analysis of plutonium proved to enhance sample utilization even further. Preliminary investigations of the instrumental fractionation behavior of plutonium and uranium analyzed via PIE methods were conducted. Data collected during these initial trial indicate that PIEs fractionate in a consistent, reproducible manner; a necessity for high precision isotope ratio measurements. Ultimately, PIEs methods were applied for the age determination of various uranium isotopic standards. PIEs did not exhibit significant advantages for the determination of model ages when compared to traditional filaments; however, this trial was able to provide valuable insight for guiding future investigations.
Download or read book Static Mixed array Total Evaporation for Improved Quantitation of Plutonium Minor Isotopes in Small Samples written by and published by . This book was released on 2016 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Actinide isotope measurements are a critical signature capability in the modern nuclear forensics "toolbox", especially when interrogating anthropogenic constituents in real-world scenarios. Unfortunately, established methodologies, such as traditional total evaporation via thermal ionization mass spectrometry, struggle to confidently measure low abundance isotope ratios (
Download or read book Improved Precision and Accuracy in Quantifying Plutonium Isotope Ratios by RIMS written by and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonance ionization mass spectrometry (RIMS) holds the promise of rapid, isobar-free quantification of actinide isotope ratios in as-received materials (i.e. not chemically purified). Recent progress in achieving this potential using two Pu test materials is presented. RIMS measurements were conducted multiple times over a period of two months on two different Pu solutions deposited on metal surfaces. Measurements were bracketed with a Pu isotopic standard, and yielded absolute accuracies of the measured 240Pu/239Pu ratios of 0.7% and 0.58%, with precisions (95% confidence intervals) of 1.49% and 0.91%. In conclusion, the minor isotope 238Pu was also quantified despite the presence of a significant quantity of 238U in the samples.
Download or read book Isotopic Measurements of Uranium and Plutonium by Resonance ionization Mass Spectrometry written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Isotopic measurements of the elements uranium and plutonium have been carried out using laser-excited resonance ionization mass spectrometry (RIMS). This technique makes use of the high elemental selectivity inherent in the resonance-ionization process which results in complete removal of isobaric (same-mass) interferences. The requirements of the laser system and atomization source will be discussed with emphasis on maximizing the efficiency of temporal overlap, thus increasing the sensitivity of the technique. Results will be shown for resin-bead loaded samples containing a mixture of NBS standard reference materials of U and Pu at the nanogram level. Data will be presented which demonstrate the selectivity, accuracy, and precision of RIMS compared to the conventional thermal ionization technique.
Download or read book Standard Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances by Thermal Ionization Mass Spectrometry written by and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Focused Ion Beams written by Lucille A. Giannuzzi and published by Springer Science & Business Media. This book was released on 2006-05-18 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Focused Ion Beams is geared towards techniques and applications. This is the only text that discusses and presents the theory directly related to applications and the only one that discusses the vast applications and techniques used in FIBs and dual platform instruments.
Download or read book Use of IsoProbe for Uranium and Plutonium Analysis in Environmental Samples written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to detect and isotopically characterize uranium and plutonium in environmental samples is of primary importance in the search for nuclear proliferation. The utility of isotope ratio measurements for environmental monitoring is limited by sample preparation costs, measurement precision, and sensitivity. This is particularly true for wide-area monitoring where the number of samples required varies inversely with obtainable precision and sensitivity. This report summarizes an initial evaluation of the applicability of a new technique, magnetic-sector, multicollector, inductively-coupled-plasma mass spectrometry, to environmental sample analysis. This technique is embodied at Lawrence Livermore National Laboratory in the form of a commercially available instrument, the IsoProbe, manufactured by micromass, LTD. (United Kingdom). This is the second of the current generation of such instruments installed in the United States and the first within the Department of Energy complex. Inductively-coupled plasma mass spectrometry (ICPMS) using quadrupole mass filters has existed for roughly 15 years. Magnet sector instruments have also existed for about half that time and multicollector instruments have existed for nearly as long. Among the things that make the new generation of instruments, and the IsoProbe in particular, unique are (1) the use of a gas-collision cell to reduce the energy spread of the ions and to remove ions associated with the plasma gas and (2) the introduction of multiple electron-multiplier detection systems. The net effect of these features is to increase sensitivity and precision. Historically uranium and plutonium isotopic compositions have been determined by thermal ionization mass spectrometry (TIMS). While requiring extensive sample preparation, no other technique matched its precision and sensitivity for such measurements. The purposes of this project are to evaluate whether the IsoProbe can replace TIMS for environmental monitoring analyses, whether it can extend the state-of-the-art to higher precision, and whether costs savings can be achieved at the same time.
Download or read book Isotope dilution Mass Spectrometry in the Measurement of Plutonium Isotope Half lives written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Isotope-dilution mass spectrometry has been used at Los Alamos to measure the half-lives of 239Pu, 24°Pu, and 241Pu. The latter was determined by measuring the rate of decrease of the 241Pu/242Pu ratio in an appropriate isotopic mixture over a period of several years. The half-lives of the two lighter isotopes are too long to be determined in this manner. They were determined by measuring the rate of production of the uranium daughter relative to a known added 233U spike. Experimental procedures were designed to control sources of error and to permit a detailed statistical treatment which included all known sources of error and accounted for all covariances. The uncertainties, at the 95% confidence level, associated with the measured half-lives were less than 0.4% for 241Pu and less than 0.2% for 239Pu and 24°Pu.
Download or read book Standard Test Method for Determination of Uranium or Plutonium Isotopic Composition or Concentration by the Total Evaporation Method Using a Thermal Ionization Mass Spectrometer written by and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Precision Isotopic Analyses of Uranium and Plutonium by Total Sample Volatilization and Signal Integration written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Techniques have been developed which permit rapid, high-precision analyses of uranium and plutonium by multiple-filament thermal ionization mass spectrometry utilizing a commercial multicollector instrument. The salient feature of the method is volatilization of the entire sample while simultaneously integrating the signal from each isotope, thus virtually eliminating the effects of isotope fractionation in the evaporation process. The method permits the analysis of samples much smaller than required for conventional techniques using Faraday collectors and is expected to have application in the analysis of many elements in addition to uranium and plutonium. Run-to-run reproducibilities of
Download or read book Inorganic Mass Spectrometry written by Sabine Becker and published by John Wiley & Sons. This book was released on 2008-02-28 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing an exhaustive review of this topic, Inorganic Mass Spectrometry: Principles and Applications provides details on all aspects of inorganic mass spectrometry, from a historical overview of the topic to the principles and functions of mass separation and ion detection systems. Offering a comprehensive treatment of inorganic mass spectrometry, topics covered include: Recent developments in instrumentation Developing analytical techniques for measurements of trace and ultratrace impurities in different materials This broad textbook in inorganic mass spectrometry, presents the most important mass spectrometric techniques used in all fields of analytical chemistry. By covering recent developments and advances in all fields of inorganic mass spectrometry, this text provides researchers and students with information to answer any questions on this topic as well as providing the basic fundamentals for understanding this potentially complex, but increasingly relevant subject.
Download or read book Rapid Mass Spectrometry Method for Uranium and Plutonium written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new, rapid sample preparation method to improve the assay of uranium and plutonium by mass spectrometry has been developed at the Westinghouse Savannah River Site (SRS). The method is applied to the analysis of mixed plutonium-uranium oxide materials but can be applied to low-level mass spectrometry analyses as well. The new method uses a single extraction chromatographic column to separate and purify both uranium and plutonium for isotopic assay by thermal ionization mass spectrometry. A dual uranium/plutonium spike isotope dilution technique is used to allow rapid analysis of uranium/plutonium content and isotopics. A single UTEVA Resin column is utilized to simultaneously separate both uranium and plutonium from the sample matrix. The plutonium and uranium can rapidly removed from the column separately or eluted together for analysis. This new method combines sample preparation into a single, effective separation step that significantly reduces sample preparation time and costs.
Download or read book Improvement in Measurements of Plutonium in Spent fuel Dissolver Solutions written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have studied the improvement in simultaneous measurements of concentrations and isotopic compositions for plutonium in input spent-fuel dissolver solutions at a reprocessing plant by isotope dilution gamma-ray spectrometry (IDGS) technique. The IDGS technique uses the high-resolution low-energy gamma-ray spectrometry and isotope dilution method. The dissolver solutions are subsequently measured using high-resolution gamma-ray spectrometry following the fission product separations by extraction chromatography using U/TEVA·Spec resins. The improved method can simplify the separation procedure and save more than 2 hours in sample preparation time. The results of plutonium concentrations and isotopic compositions of dissolver solutions analyzed by IDGS agree very well with those obtained by traditional isotope dilution mass spectrometry. The rapid and accurate IDGS technique with the improved separation method could provide a timely, less expensive, and simpler on-site verification method for the input accountability measurements.
Download or read book Standard test method for determination of uranium or plutonium isotopic composition or concentration by the total evaporation method using a thermal ionization mass spectrometer written by ASTM International and published by . This book was released on 2017 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mass Spectrometric Measurements of Natural Isotopic Spectra written by R. F. Hibbs and published by . This book was released on 1949 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mass Spectrometry for Uranium Isotopic Measurements written by Charles Dewey Tabor and published by . This book was released on 1960 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
