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 Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry written by Brett Hallen Isselhardt and published by . This book was released on 2011 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with automated feedback control of wavelength was applied to the measurement of 235U/238U ratios to decrease laser-induced isotopic fractionation. By broadening the bandwidth of the first laser in a 3-color, 3-photon ionization process from a bandwidth of 1.8 GHz to about 10 GHz, the variation in sequential relative isotope abundance measurements decreased from>10% to less than 0.5%. This procedure was demonstrated for the direct interrogation of uranium oxide targets with essentially no sample preparation. A rate equation model for predicting the relative ionization probability has been developed to study the effect of variation in laser parameters on the measured isotope ratio. This work demonstrates that RIMS can be used for the robust measurement of uranium isotope ratios.
Download or read book Uranium Isotopic Standard Reference Materials written by E. L. Garner and published by . This book was released on 1971 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Standard Reference Materials Uranium Isotopic Standard Reference Materials written by L. E. Garner and published by . This book was released on 1971 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultra sensitive Isotopic Analysis by Resonance Ionization Mass Spectrometry written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A high-powered pulsed dye laser has been interfaced to a commerical ion microprobe mass analyzer. This combination should provide ultra-high sensitivity for isotope ratio measurements of selected elements in environmental samples. The technique is an outgrowth of resonance ionization mass spectrometry which has demonstrated high precision for isotope ratio determinations of uranium and plutonium using thermal filament atomization. Sputter atomization using a pulsed argon ion beam represents a significant improvement in efficiency because the temporal overlap between the atom cloud and the laser pulse can approach 100%. This, coupled with the high ionization efficiency of laser induced resonance ionization methods, promises an analytical sensitivity which is significantly better than other microprobe techniques. A description of the experimental set-up is given along with the modifications to the ion microprobe instrument which were necessary to obtain acceptable ion extraction efficiency. Also shown are results for samarium and uranium demonstrating the optical and mass spectra obtained. 21 refs., 7 figs., 1 tab.
Download or read book Uranium Isotope Measurements with a Model SU 1 Surface Ionization Mass Spectrometer written by V. L. Warren and published by . This book was released on 1962 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A World Without Sample Preparation written by and published by . This book was released on 2009 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We are developing highly sensitive, highly discriminating laser-based techniques for rapid determination of isotopic compositions. Rapid command of such information is critical to assessment of the origin and history of nuclear materials, particularly in post-detonation scenarios.
Download or read book Determination of Uranium and Plutonium Concentrations and Isotopic Abundances written by B. F. Rider and published by . This book was released on 1964 with total page 60 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:
Download or read book Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry written by and published by . This book was released on 2011 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with automated feedback control of wavelength was applied to the measurement of 235U/238U ratios to decrease laser-induced isotopic fractionation. By broadening the bandwidth of the first laser in a 3-color, 3-photon ionization process from a bandwidth of 1.8 GHz to about 10 GHz, the variation in sequential relative isotope abundance measurements decreased from >10% to less than 0.5%. This procedure was demonstrated for the direct interrogation of uranium oxide targets with essentially no sample preparation. A rate equation model for predicting the relative ionization probability has been developed to study the effect of variation in laser parameters on the measured isotope ratio. This work demonstrates that RIMS can be used for the robust measurement of uranium isotope ratios.
Download or read book Measurement of the Isotopic Enrichment of Uranium by a Direct Comparison Mass Spectrometer Method written by V. L. Warren and published by . This book was released on 1958 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Aspects of the Precise and Accurate Determination of Uranium and Plutonium from Nuclear Fuel Solutions written by Olli J. Heinonen and published by . This book was released on 1981 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Impurity Effects in the Mass Spectrometer Isotopic Analysis of Uranium Hexafluoride written by J. C. Horton and published by . This book was released on 1958 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Modern Isotope Ratio Mass Spectrometry written by I. T. Platzner and published by John Wiley & Sons. This book was released on 1997-10-22 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: I. T. Platzner Atomic Energy Commission, Israel Including contributions from instrument manufacturers! Geological aging, chemical reaction mechanism studies, determination of atomic weights and investigation of metabolic pathways-these are all examples of the truly diverse nature of isotope ratio mass spectrometry (IRMS). With applications in fields as far apart as analytical chemistry and astronomy, geochemistry and biomedical science, it is little wonder that this technique is becoming increasingly popular. In Modern Isotope Ratio Mass Spectrometry,the first comprehensive book written on the subject for twenty-five years, examples from all these areas, and many more,are given. All modern developments in this fascinating field are discussed with special attention paid to technical details and instrumentation. Features of the book include: * comprehensive element-by-element review including 94 elements * applications chapter which stresses multi-disciplinary nature of subject * instrumentation chapter with contributions from three leading industrialists on state-of-the-art instrumentation
Download or read book The Determination of Uranium Isotope Abundances and Reactor Fuel Burnup by Mass Spectrometry written by D. E. Fornwalt and published by . This book was released on 1963 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
