Sample records for occurring isotopes mass

  1. Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

    SciTech Connect (OSTI)

    Svensson, Jan, E-mail: jan.svensson@ki.se [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden) [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Bergman, Ann-Charlotte [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden)] [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Adamson, Ulf [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)] [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden); Blombaeck, Margareta [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden)] [Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital (Solna), SE-171 76 Stockholm (Sweden); Wallen, Hakan; Joerneskog, Gun [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)] [Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm (Sweden)

    2012-05-04T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Fibrinogen was incubated in vitro with glucose or aspirin. Black-Right-Pointing-Pointer Acetylations and glycations were found at twelve lysine sites by mass spectrometry. Black-Right-Pointing-Pointer The labeling by aspirin and glucose occurred dose-dependently. Black-Right-Pointing-Pointer No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called 'aspirin resistance'. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to 'aspirin resistance' in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the {alpha}-chain: {alpha}K191, {alpha}K208, {alpha}K224, {alpha}K429, {alpha}K457, {alpha}K539, {alpha}K562, in the {beta}-chain: {beta}K233, and in the {gamma}-chain: {gamma}K170 and {gamma}K273. Glycations were found at {beta}K133 and {gamma}K75, alternatively {gamma}K85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [{sup 14}C-acetyl]salicylic acid and [{sup 14}C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 {mu}M aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen. This may mechanistically explain why aspirin facilitates fibrin degradation. We find no support for the idea that glycation of fibrin(ogen) interferes with acetylation of fibrinogen.

  2. Existence of long-lived isomeric states in naturally-occurring neutron-deficient Th isotopes

    E-Print Network [OSTI]

    A. Marinov; I. Rodushkin; Y. Kashiv; L. Halicz; I. Segal; A. Pape; R. V. Gentry; H. W. Miller; D. Kolb; R. Brandt

    2006-05-10T23:59:59.000Z

    Evidence for the existence of long-lived neutron-deficient isotopes has been found in a study of naturally-occurring Th using iductively coupled plasma-sector field mass spectrometry. They are interpreted as belonging to the recently discovered class of long-lived high spin super- and hyperdeformed isomers.

  3. Mass Parameterizations and Predictions of Isotopic Observables

    E-Print Network [OSTI]

    S. R. Souza; P. Danielewicz; S. Das Gupta; R. Donangelo; W. A. Friedman; W. G. Lynch; W. P. Tan; M. B. Tsang

    2003-03-24T23:59:59.000Z

    We discuss the accuracy of mass models for extrapolating to very asymmetric nuclei and the impact of such extrapolations on the predictions of isotopic observables in multifragmentation. We obtain improved mass predictions by incorporating measured masses and extrapolating to unmeasured masses with a mass formula that includes surface symmetry and Coulomb terms. We find that using accurate masses has a significant impact on the predicted isotopic observables.

  4. Advanced Mass Spectrometers for Hydrogen Isotope Analyses

    SciTech Connect (OSTI)

    Chastagner, P.

    2001-08-01T23:59:59.000Z

    This report is a summary of the results of a joint Savannah River Laboratory (SRL) - Savannah River Plant (SRP) ''Hydrogen Isotope Mass Spectrometer Evaluation Program''. The program was undertaken to evaluate two prototype hydrogen isotope mass spectrometers and obtain sufficient data to permit SRP personnel to specify the mass spectrometers to replace obsolete instruments.

  5. Compact hydrogen/helium isotope mass spectrometer

    DOE Patents [OSTI]

    Funsten, Herbert O. (Los Alamos, NM); McComas, David J. (Los Alamos, NM); Scime, Earl E. (Morgantown, WV)

    1996-01-01T23:59:59.000Z

    The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

  6. O isotopic composition of CaCO3 measured by continuous ow isotope ratio mass spectrometry

    E-Print Network [OSTI]

    d13 C and d18 O isotopic composition of CaCO3 measured by continuous ¯ow isotope ratio mass. This new method streamlines the classical phosphoric acid/calcium carbonate (H3PO4/CaCO3) reaction method XL continuous flow isotope ratio mass spectrometer. Conditions for which the H3PO4/CaCO3 reaction

  7. Isotopic mass-dependence of noble gas diffusion coefficients inwater

    SciTech Connect (OSTI)

    Bourg, I.C.; Sposito, G.

    2007-06-25T23:59:59.000Z

    Noble gas isotopes are used extensively as tracers inhydrologic and paleoclimatic studies. These applications requireknowledge of the isotopic mass (m) dependence of noble gas diffusioncoefficients in water (D), which has not been measured but is estimatedusing experimental D-values for the major isotopes along with an untestedrelationship from kinetic theory, D prop m-0.5. We applied moleculardynamics methods to determine the mass dependence of D for four noblegases at 298 K, finding that D prop m-beta with beta<0.2, whichrefutes the kinetic theory model underlying all currentapplications.

  8. O Isotopic Composition of CaCO3 Measured by Continuous Flow Isotope Ratio Mass Spectrometry: Statistical Evaluation and

    E-Print Network [OSTI]

    d13 C and d18 O Isotopic Composition of CaCO3 Measured by Continuous Flow Isotope Ratio Mass method streamlines the classical phosphoric acid ­ calcium carbonate (H3 PO4 ­ CaCO3 ) reaction method XL continuous flow isotope ratio mass spectrometer. Conditions for which the H3 PO4 ­ CaCO3 reaction

  9. Ion Mobility Mass Spectrometry Direct Isotope Abundance Analysis

    SciTech Connect (OSTI)

    Manuel J. Manard, Stephan Weeks, Kevin Kyle

    2010-05-27T23:59:59.000Z

    The nuclear forensics community is currently engaged in the analysis of illicit nuclear or radioactive material for the purposes of non-proliferations and attribution. One technique commonly employed for gathering nuclear forensics information is isotope analysis. At present, the state-of-the-art methodology for obtaining isotopic distributions is thermal ionization mass spectrometry (TIMS). Although TIMS is highly accurate at determining isotope distributions, the technique requires an elementally pure sample to perform the measurement. The required radiochemical separations give rise to sample preparation times that can be in excess of one to two weeks. Clearly, the nuclear forensics community is in need of instrumentation and methods that can expedite their decision making process in the event of a radiological release or nuclear detonation. Accordingly, we are developing instrumentation that couples a high resolution IM drift cell to the front end of a MS. The IM cell provides a means of separating ions based upon their collision cross-section and mass-to-charge ratio (m/z). Two analytes with the same m/z, but with different collision cross-sections (shapes) would exit the cell at different times, essentially enabling the cell to function in a similar manner to a gas chromatography (GC) column. Thus, molecular and atomic isobaric interferences can be effectively removed from the ion beam. The mobility selected chemical species could then be introduced to a MS for high-resolution mass analysis to generate isotopic distributions of the target analytes. The outcome would be an IM/MS system capable of accurately measuring isotopic distributions while concurrently eliminating isobaric interferences and laboratory radiochemical sample preparation. The overall objective of this project is developing instrumentation and methods to produce near real-time isotope distributions with a modular mass spectrometric system that performs the required gas-phase chemistry and separations. The system couples a high-resolution ion mobility (IM) drift cell to the front end of a mass spectrometer (MS) allowing for chemical separation prior to isotope distribution analyses. This will yield isotope ratio measurement capabilities with minimal sample preparation.

  10. Oxygen isotopic ratios in intermediate-mass red giants

    E-Print Network [OSTI]

    Lebzelter, Thomas; Hinkle, Kenneth; Nowotny, Walter; Aringer, Bernhard

    2015-01-01T23:59:59.000Z

    Context. The abundances of the three main isotopes of oxygen are altered in the course of the CNO-cycle. When the first dredge-up mixes the burning products to the surface, the nucleosynthesis processes can be probed by measuring oxygen isotopic ratios. Aims. By measuring 16O/17O and 16O/18O in red giants of known mass we compare the isotope ratios with predictions from stellar and galactic evolution modelling. Methods. Oxygen isotopic ratios were derived from the K-band spectra of six red giants. The sample red giants are open cluster members with known masses of between 1.8 and 4.5 Msun . The abundance determination employs synthetic spectra calculated with the COMARCS code. The effect of uncertainties in the nuclear reaction rates, the mixing length, and of a change in the initial abundance of the oxygen isotopes was determined by a set of nucleosynthesis and mixing models using the FUNS code. Results. The observed 16O/17O ratios are in good agreement with the model results, even if the measured values do ...

  11. Ra, a naturally occurring isotope of the 238 U-series with a

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    for counting, liquid scintillation, or mass spectrometry at comparable activities, the simple setup, low cost- fiber and is continuously transferred to a scintillation cham- 226 Ra determination via the rate of 222

  12. Measurement of positional isotope exchange rates in enzyme catalyzed reactions by fast atom bombardment mass spectrometry

    E-Print Network [OSTI]

    Hilscher, Larry Wayne

    1985-01-01T23:59:59.000Z

    A Synthetas e Positional Isotope Exchange with Argininosuccinate Synthetas e Fast Atom Bombardment Mass Spectrometry 31 P Nuclear Magnetic Resonance RESULTS Page 16 17 19 20 21 21 22 23 Positional Isotope Exchange with Acetyl CoA Synthetase... Positional Isotope Exchange with Argininosuccinate Synth etas e DISCUSSICN 23 27 30 Positional Isotope Exchange with Acetyl CoA Synthetase . Pcsitional Isotope Exchange with Argininosuccinate Synthetase RFZERENCES 30 VITA LIST OF SCHEMES Page...

  13. Intramolecular Isotope Effects for the Study of Reactions with MassTransfer Limitations

    E-Print Network [OSTI]

    Wagner, Joshua G.

    2010-01-16T23:59:59.000Z

    The research presented provides a method to use the comparison of intermolecular isotope effects vs. the intramolecular isotope effects for the study of reactions in which study of the rate limiting step is ambiguous due to interfering mass transfer...

  14. An intramolecular theory of the mass-independent isotope effect for ozone. I.

    E-Print Network [OSTI]

    Hathorn, Bryan C.

    An intramolecular theory of the mass-independent isotope effect for ozone. I. B. C. Hathorn and R-independent isotope effect for ozone formation and dissociation is described. The experiments include the enrichment and asymmetric ozone isotopomers, the enrichment of ozone formed from heavily enriched oxygen isotopes

  15. Efficient Analysis of Mass Spectrometry Data Using the Isotope Wavelet

    SciTech Connect (OSTI)

    Hussong, Rene; Hildebrandt, Andreas [Center for Bioinformatics, Computer Science Department, Saarland University, 66041 Saarbruecken (Germany); Tholey, Andreas [Center for Bioinformatics, Institute of Biochemical Engineering, Functional Proteomics Group, Saarland University, 66041 Saarbruecken (Germany)

    2007-09-18T23:59:59.000Z

    Mass spectrometry (MS) has become today's de-facto standard for high-throughput analysis in proteomics research. Its applications range from toxicity analysis to MS-based diagnostics. Often, the time spent on the MS experiment itself is significantly less than the time necessary to interpret the measured signals, since the amount of data can easily exceed several gigabytes. In addition, automated analysis is hampered by baseline artifacts, chemical as well as electrical noise, and an irregular spacing of data points. Thus, filtering techniques originating from signal and image analysis are commonly employed to address these problems. Unfortunately, smoothing, base-line reduction, and in particular a resampling of data points can affect important characteristics of the experimental signal. To overcome these problems, we propose a new family of wavelet functions based on the isotope wavelet, which is hand-tailored for the analysis of mass spectrometry data. The resulting technique is theoretically well-founded and compares very well with standard peak picking tools, since it is highly robust against noise spoiling the data, but at the same time sufficiently sensitive to detect even low-abundant peptides.

  16. The Influence of Isotopic Mass, Edge Magnetic Shear and Input Power on High Density ELMy H-modes in JET

    E-Print Network [OSTI]

    The Influence of Isotopic Mass, Edge Magnetic Shear and Input Power on High Density ELMy H-modes in JET

  17. A Hydrogen Isotope of Mass 2 Before the publication of this definitive paper on the

    E-Print Network [OSTI]

    A Hydrogen Isotope of Mass 2 Before the publication of this definitive paper on the discovery of deuterium [1,2], the existence of a heavy isotope of hydrogen had been suspected even though Aston [3 at a hydrogen abundance ratio 1 H/2 H

  18. Standard test method for uranium and plutonium concentrations and isotopic abundances by thermal ionization mass spectrometry

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2005-01-01T23:59:59.000Z

    1.1 This test method covers the determination of the concentration and isotopic composition of uranium and plutonium in solutions. The purified uranium or plutonium from samples ranging from nuclear materials to environmental or bioassay matrices is loaded onto a mass spectrometric filament. The isotopic ratio is determined by thermal ionization mass spectrometry, the concentration is determined by isotope dilution. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish safety and health practices and determine the applicability of regulatory limitations prior to use.

  19. ISOTOPES

    E-Print Network [OSTI]

    Lederer, C. Michael

    2013-01-01T23:59:59.000Z

    rare (0.017%) isotope 36s at enrichments of 70% at a price32). The enrichment of carbon isotopes by C02-carbamatesulfur isotopes by S02-NaHS03 exchange and the enrichment of

  20. Isotopically selective, Doppler-free, saturation spectroscopy of lutetium isotopes via resonance ionization mass spectrometry

    SciTech Connect (OSTI)

    Fearey, B.L.; Parent, D.C.; Keller, R.A.; Miller, C.M.

    1988-01-01T23:59:59.000Z

    A new technique utilizing RIMS to obtain very high resolution atomic spectra with isotopic selectivity has been demonstrated. This technique allows the precise determination of HF splitting constants, limited only by the transition's natural linewidth. In addition, it is also feasible with this technique to accurately determine atomic isotope shifts. The exact determination of HF component line positions provides data for isotopically selective ionization which, in turn, will increase RIMS' dynamic range. Future work includes the incorporation of a /open quotes/vibrating/close quotes/ mirror and the study of rarer isotopes, i.e., /sup 174/Lu, /sup 173/Lu, /sup 172/Lu, /sup 171/Lu, and possibly, /sup 170/Lu. 13 refs., 3 figs.

  1. Very high resolution saturation spectroscopy of lutetium isotopes via c-w single-frequency laser resonance ionization mass spectrometry

    SciTech Connect (OSTI)

    Fearey, B.L.; Parent, D.C.; Keller, R.A.; Miller, C.M.

    1987-01-01T23:59:59.000Z

    In this paper, we discuss the use of Resonance Ionization Mass Spectrometry (RIMS) to perform isotopically selective saturation spectroscopy of lutetium isotopes. Utilizing this technique, it is shown that accurate measurements of the relative frequencies of hyperfine (HF) components for different isotopes easily can be made without the need for an isotopically enriched sample. The precision with which the HF splitting constants can be determined is estimated to be approx.5 times greater than in previous work.

  2. Inductively coupled plasma mass spectrometry for stable isotope metabolic tracer studies of living systems

    SciTech Connect (OSTI)

    Luong, E.

    1999-05-10T23:59:59.000Z

    This dissertation focuses on the development of methods for stable isotope metabolic tracer studies in living systems using inductively coupled plasma single and dual quadrupole mass spectrometers. Sub-nanogram per gram levels of molybdenum (Mo) from human blood plasma are isolated by the use of anion exchange alumina microcolumns. Million-fold more concentrated spectral and matrix interferences such as sodium, chloride, sulfate, phosphate, etc. in the blood constituents are removed from the analyte. The recovery of Mo from the alumina column is 82 {+-} 5% (n = 5). Isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) is utilized for the quantitative ultra-trace concentration determination of Mo in bovine and human blood samples. The average Mo concentration in reference bovine serum determined by this method is 10.2 {+-} 0.4 ng/g, while the certified value is 11.5 {+-} 1.1 ng/g (95% confidence interval). The Mo concentration of one pool of human blood plasma from two healthy male donors is 0.5 {+-} 0.1 ng/g. The inductively coupled plasma twin quadrupole mass spectrometer (ICP-TQMS) is used to measure the carbon isotope ratio from non-volatile organic compounds and bio-organic molecules to assess the ability as an alternative analytical method to gas chromatography combustion isotope ratio mass spectrometry (GC-combustion-IRMS). Trytophan, myoglobin, and {beta}-cyclodextrin are chosen for the study, initial observation of spectral interference of {sup 13}C{sup +} with {sup 12}C{sup 1}H{sup +} comes from the incomplete dissociation of myoglobin and/or {beta}-cyclodextrin.

  3. Measurement of positional isotope exchange rates in enzyme catalyzed reactions by fast atom bombardment mass spectrometry 

    E-Print Network [OSTI]

    Hilscher, Larry Wayne

    1985-01-01T23:59:59.000Z

    utility in analyzing a wide array of biological compounds. Our laboratory became interested in the potential use of FAB-MS to study PIX in nucleotide . Working with Dr. David H. Russell's group (Dept. of Chemistry, Texas A A M University) we were able...MEASUREMENT OF POSITIONAL ISOTOPE EXCHANGE RATES IN ENZYME CATALYZED REACTIONS BY FAST ATOM BOMBARDMENT MASS SPECTROMETRY A Thesis by LARRY NAYNE HILSCHER Submitted to the Gradu te College of Texas A&M University in partial fulfil" mert...

  4. Mass-related inversion symmetry breaking and phonon self-energy renormalization in isotopically labeled AB-stacked bilayer graphene

    E-Print Network [OSTI]

    Araujo, Paulo Antonio Trinidade

    A mass-related symmetry breaking in isotopically labeled bilayer graphene (2LG) was investigated during in-situ electrochemical charging of AB stacked (AB-2LG) and turbostratic (t-2LG) layers. The overlap of the two ...

  5. SO[subscript 2] photolysis as a source for sulfur mass-independent isotope signatures in stratospehric aerosols

    E-Print Network [OSTI]

    Jiang, B.

    Signatures of sulfur isotope mass-independent fractionation (S-MIF) have been observed in stratospheric sulfate aerosols deposited in polar ice. The S-MIF signatures are thought to be associated with stratospheric ...

  6. THE GENESIS SOLAR WIND CONCENTRATOR TARGET: MASS FRACTIONATION CHARACTERISED BY NE ISOTOPES

    SciTech Connect (OSTI)

    WIENS, ROGER C. [Los Alamos National Laboratory; OLINGER, C. [Los Alamos National Laboratory; HEBER, V.S. [Los Alamos National Laboratory; REISENFELD, D.B. [Los Alamos National Laboratory; BURNETT, D.S. [Los Alamos National Laboratory; ALLTON, J.H. [Los Alamos National Laboratory; BAUR, H. [Los Alamos National Laboratory; WIECHERT, U. [Los Alamos National Laboratory; WIELER, R. [Los Alamos National Laboratory

    2007-01-02T23:59:59.000Z

    The concentrator on Genesis provides samples of increased fluences of solar wind ions for precise determination of the oxygen isotopic composition of the solar wind. The concentration process caused mass fractionation as function of the radial target position. They measured the fractionation using Ne released by UV laser ablation along two arms of the gold cross from the concentrator target to compare measured Ne with modeled Ne. The latter is based on simulations using actual conditions of the solar wind during Genesis operation. Measured Ne abundances and isotopic composition of both arms agree within uncertainties indicating a radial symmetric concentration process. Ne data reveal a maximum concentration factor of {approx} 30% at the target center and a target-wide fractionation of Ne isotopes of 3.8%/amu with monotonously decreasing {sup 20}Ne/{sup 22}Ne ratios towards the center. The experimentally determined data, in particular the isotopic fractionation, differ from the modeled data. They discuss potential reasons and propose future attempts to overcome these disagreements.

  7. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.

    SciTech Connect (OSTI)

    Keck, B D; Ognibene, T; Vogel, J S

    2010-02-05T23:59:59.000Z

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg equivalents. AMS provides an sensitive, accurate and precise method of measuring drug compounds in biological matrices.

  8. Examination of the rate of peptide biosynthesis in neuroendocrine cell lines using a stable isotopic label and mass spectrometry

    E-Print Network [OSTI]

    Tian, Weidong

    isotopic label and mass spectrometry Fa-Yun Che,*,1 Quan Yuan,* ,1 Elena Kalinina* and Lloyd D. Fricker-Leu) and used mass spectrometry to measure the biosynthetic rate of c-lipotropin in the AtT-20 cell lines. Keywords: carboxypeptidase, gamma-lipotropin, insulin, prohormone convertase, proinsulin

  9. Isotopes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  10. A Mass Spectrometry Study of Isotope Separation in the Laser Plume

    E-Print Network [OSTI]

    Suen, Timothy Wu

    2012-01-01T23:59:59.000Z

    Zhang, and J. A. Nees, “Isotope Enrichment in Laser-AblationA. Naik, “Comment on “Isotope Enrichment in Laser-AblationP. Pronko, “Isotope separation and enrichment by ultrafast

  11. New precision mass measurements of neutron-rich calcium and potassium isotopes and three-nucleon forces

    E-Print Network [OSTI]

    A. T. Gallant; J. C. Bale; T. Brunner; U. Chowdhury; S. Ettenauer; A. Lennarz; D. Robertson; V. V. Simon; A. Chaudhuri; J. D. Holt; A. A. Kwiatkowski; E. Mané; J. Menéndez; B. E. Schultz; M. C. Simon; C. Andreoiu; P. Delheij; M. R. Pearson; H. Savajols; A. Schwenk; J. Dilling

    2012-04-09T23:59:59.000Z

    We present precision Penning-trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity of neutron number N=32. Using the TITAN system the mass of $^{51}$K was measured for the first time, and the precision of the $^{51,52}$Ca mass values were improved significantly. The new mass values show a dramatic increase of the binding energy compared to those reported in the atomic mass evaluation. In particular, $^{52}$Ca is more bound by 1.74 MeV, and the behavior with neutron number deviates substantially from the tabulated values. An increased binding was predicted recently based on calculations that include three-nucleon (3N) forces. We present a comparison to improved calculations, which agree remarkably with the evolution of masses with neutron number, making neutron-rich calcium isotopes an exciting region to probe 3N forces at neutron-rich extremes.

  12. Assessment of Non-traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear Activities: Annual Report Year 2

    SciTech Connect (OSTI)

    Biegalski, S; Buchholz, B

    2009-08-26T23:59:59.000Z

    The objective of this work is to identify isotopic ratios suitable for analysis via mass spectrometry that distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Methods will also be determined to distinguish the above from medical and industrial radionuclide sources. Mass spectrometry systems will be identified that are suitable for field measurement of such isotopes in an expedient manner. Significant progress has been made with this project within the past year: (1) Isotope production from commercial nuclear fuel cycles and nuclear weapons fuel cycles have been modeled with the ORIGEN and MCNPX codes. (2) MCNPX has been utilized to calculate isotopic inventories produced in a short burst fast bare sphere reactor (to approximate the signature of a nuclear weapon). (3) Isotopic ratios have been identified that are good for distinguishing between commercial and military fuel cycles as well as between nuclear weapons and commercial nuclear fuel cycles. (4) Mass spectrometry systems have been assessed for analysis of the fission products of interest. (5) A short-list of forensic ratios have been identified that are well suited for use in portable mass spectrometry systems.

  13. Spatially tracking 13C labeled substrate (bicarbonate) accumulation in microbial communities using laser ablation isotope ratio mass spectrometry

    SciTech Connect (OSTI)

    Moran, James J.; Doll, Charles G.; Bernstein, Hans C.; Renslow, Ryan S.; Cory, Alexandra B.; Hutchison, Janine R.; Lindemann, Stephen R.; Fredrickson, Jim K.

    2014-08-25T23:59:59.000Z

    This is a manuscript we would like to submit for publication in Environmental Microbiology Reports. This manuscript contains a description of a laser ablation isotope ratio mass spectrometry methodology developed at PNNL and applied to a microbial system at a PNNL project location – Hot Lake, Washington. I will submit a word document containing the entire manuscript with this Erica input request form.

  14. Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability

    SciTech Connect (OSTI)

    Isselhardt, B H

    2011-09-06T23:59:59.000Z

    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 {sup 235}U/{sup 238}U 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.

  15. Discovering Mercury Protein Modifications in Whole Proteomes Using Natural Isotope Distributions Observed in Liquid Chromatography-Tandem Mass Spectrometry

    SciTech Connect (OSTI)

    Polacco, Benjamin J.; Purvine, Samuel O.; Zink, Erika M.; LaVoie, Stephen P.; Lipton, Mary S.; Summers, Anne O.; Miller, Susan M.

    2011-08-01T23:59:59.000Z

    The identification of peptides that result from post-translational modifications is critical for understanding normal pathways of cellular regulation as well as identifying damage from, or exposures to xenobiotics, i.e. the exposome. However, because of their low abundance in proteomes, effective detection of modified peptides by mass spectrometry (MS) typically requires enrichment to eliminate false identifications. We present a new method for confidently identifying peptides with mercury (Hg)-containing adducts that is based on the influence of mercury’s seven stable isotopes on peptide isotope distributions detected by high-resolution MS. Using a pure protein and E. coli cultures exposed to phenyl mercuric acetate, we show the pattern of peak heights in isotope distributions from primary MS single scans efficiently identified Hg adducts in data from chromatographic separation coupled with tandem mass spectrometry with sensitivity and specificity greater than 90%. Isotope distributions are independent of peptide identifications based on peptide fragmentation (e.g. by SEQUEST), so both methods can be combined to eliminate false positives. Summing peptide isotope distributions across multiple scans improved specificity to 99.4% and sensitivity above 95%, affording identification of an unexpected Hg modification. We also illustrate the theoretical applicability of the method for detection of several less common elements including the essential element, selenium, as selenocysteine in peptides.

  16. Standard test method for isotopic analysis of uranium hexafluoride by double standard single-collector gas mass spectrometer method

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2010-01-01T23:59:59.000Z

    1.1 This is a quantitative test method applicable to determining the mass percent of uranium isotopes in uranium hexafluoride (UF6) samples with 235U concentrations between 0.1 and 5.0 mass %. 1.2 This test method may be applicable for the entire range of 235U concentrations for which adequate standards are available. 1.3 This test method is for analysis by a gas magnetic sector mass spectrometer with a single collector using interpolation to determine the isotopic concentration of an unknown sample between two characterized UF6 standards. 1.4 This test method is to replace the existing test method currently published in Test Methods C761 and is used in the nuclear fuel cycle for UF6 isotopic analyses. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro...

  17. Vibronic origin of sulfur mass-independent isotope effect in photoexcitation of SO[subscript 2] and the implications to the early earth's atmosphere

    E-Print Network [OSTI]

    Whitehill, Andrew Richard

    Signatures of mass-independent isotope fractionation (MIF) are found in the oxygen ([superscript 16]O, [superscript 17]O, [superscript 18]O) and sulfur ([superscript 32]S, [superscript 33]S, [superscript 34]S, [superscript ...

  18. {beta}{sub {beta}} measurements of neutron-rich isotopes in the mass region 147{le}A{le}152

    SciTech Connect (OSTI)

    Ikuta, T.; Taniguchi, A.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Kawase, Y. [Kyoto Univ., Osaka (Japan)

    1994-12-31T23:59:59.000Z

    The systematic Q{sub {beta}} measurements of 14 neutron-rich nuclei in the mass region from A=147 to A=152 have been performed with an HPGe detector. Neutron-rich nuclei were mass-separated from the thermal neutron induced fission of {sup 235}U using a He-N{sub 2} mixture-jet type on-line isotope separator which has been developed at the Kyoto University Reactor (KUR-ISOL). From a {beta}-ray singles and {beta}-{gamma} coincidence measurements, the Q{sub {beta}} values of {sup 147}La, {sup 147-150}Ce, {sup 147-152}Pr, {sup 152}Nd and {sup 152}Pm have been determined. In addition, the atomic masses derived from the experimental Q{sub {beta}} values are compared with the predictions of theoretical mass calculations.

  19. DETERMINATION OF 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    SciTech Connect (OSTI)

    Maxwell, S.

    2010-07-26T23:59:59.000Z

    A new method for the determination of {sup 237}Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of {sup 237}Np and Pu isotopes by ICP-MS. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via {sup 238}U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1 x 10{sup 6}. Alpha spectrometry can also be applied so that the shorter-lived {sup 238}Pu isotope can be measured successfully. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu and {sup 238}Pu were measured by alpha spectrometry.

  20. Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability

    E-Print Network [OSTI]

    Isselhardt, Brett Hallen

    2011-01-01T23:59:59.000Z

    Isotope Ratios from U 3 O 8 Standards of Varying Enrichmentprobability. Enrichment of the odd isotope compared to 238 Ufrom an enrichment of the lighter isotope of almost 40 %

  1. RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY

    SciTech Connect (OSTI)

    Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

    2010-06-23T23:59:59.000Z

    A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

  2. Isolation and Puification of Uranium Isotopes for Measurement by Mass-Spectrometry (233, 234, 235, 236, 238U) and Alpha Spectrometry (232U)

    SciTech Connect (OSTI)

    Marinelli, R; Hamilton, T; Brown, T; Marchetti, A; Williams, R; Tumey, S

    2006-05-30T23:59:59.000Z

    This report describes a standardized methodology used by researchers from the Center for Accelerator Mass Spectrometry (CAMS) (Energy and Environment Directorate) and the Environmental Radiochemistry Group (Chemistry and Materials Science Directorate) at the Lawrence Livermore National Laboratory (LLNL) for the full isotopic analysis of uranium from solution. The methodology has largely been developed for use in characterizing the uranium composition of selected nuclear materials but may also be applicable to environmental studies and assessments of public, military or occupational exposures to uranium using in-vitro bioassay monitoring techniques. Uranium isotope concentrations and isotopic ratios are measured using a combination of Multi Collector Inductively Coupled Plasma Mass Spectrometry (MC ICP-MS), Accelerator Mass Spectrometry (AMS) and Alpha Spectrometry.

  3. Standard test method for determination of uranium or plutonium isotopic composition or concentration by the total evaporation method using a thermal ionization mass spectrometer

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2007-01-01T23:59:59.000Z

    1.1 This method describes the determination of the isotopic composition and/or the concentration of uranium and plutonium as nitrate solutions by the thermal ionization mass spectrometric (TIMS) total evaporation method. Purified uranium or plutonium nitrate solutions are loaded onto a degassed metal filament and placed in the mass spectrometer. Under computer control, ion currents are generated by heating of the filament(s). The ion beams are continually measured until the sample is exhausted. The measured ion currents are integrated over the course of the run, and normalized to a reference isotope ion current to yield isotopic ratios. 1.2 In principle, the total evaporation method should yield isotopic ratios that do not require mass bias correction. In practice, some samples may require this bias correction. When compared to the conventional TIMS method, the total evaporation method is approximately two times faster, improves precision from two to four fold, and utilizes smaller sample sizes. 1.3 The tot...

  4. Development of a portable mass spectrometric system for determination of isotopic composition of solid uranium samples using fluorine volatilization. Final report

    SciTech Connect (OSTI)

    Loge, G.

    1994-09-30T23:59:59.000Z

    Using hardware and materials supplied by LANL, a prototype quadrupole mass spectrometer system designed for portable field analysis of isotopic composition of solid uranium samples was assembled and tested. The system contained the capability for fluorine volatilization of solid uranium samples with gas introduction, which was successfully tested and demonstrated using 100 mg samples of U{sub 3}O{sub 8}. Determination of precision and accuracy for measuring isotopic composition was performed using isotopic standards. Use with soil samples containing uranium were also attempted. Silicates in the soil forming SiF{sub 4} were found to be a kinetic bottleneck to the formation of UF{sub 6}. This could be avoided by performing some sort of chemical separation as a pre-treatment step, which was demonstrated using nitric acid.

  5. Probing the N = 32 shell closure below the magic proton number Z = 20: Mass measurements of the exotic isotopes 52,53K

    E-Print Network [OSTI]

    M. Rosenbusch; P. Ascher; D. Atanasov; C. Barbieri; D. Beck; K. Blaum; Ch. Borgmann; M. Breitenfeldt; R. B. Cakirli; A. Cipollone; S. George; F. Herfurth; M. Kowalska; S. Kreim; D. Lunney; V. Manea; P. Navrátil; D. Neidherr; L. Schweikhard; V. Somà; J. Stanja; F. Wienholtz; R. N. Wolf; K. Zuber

    2015-06-01T23:59:59.000Z

    The recently confirmed neutron-shell closure at N = 32 has been investigated for the first time below the magic proton number Z = 20 with mass measurements of the exotic isotopes 52,53K, the latter being the shortest-lived nuclide investigated at the online mass spectrometer ISOLTRAP. The resulting two-neutron separation energies reveal a 3 MeV shell gap at N = 32, slightly lower than for 52Ca, highlighting the doubly-magic nature of this nuclide. Skyrme-Hartree-Fock-Boguliubov and ab initio Gorkov-Green function calculations are challenged by the new measurements but reproduce qualitatively the observed shell effect.

  6. Accurate determination of Curium and Californium isotopic ratios by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 248Cm samples for transmutation studies

    SciTech Connect (OSTI)

    Gourgiotis, A.; Isnard, H.; Aubert, M.; Dupont, E.; AlMahamid, I.; Cassette, P.; Panebianco, S.; Letourneau, A.; Chartier, F.; Tian, G.; Rao, L.; Lukens, W.

    2011-02-01T23:59:59.000Z

    The French Atomic Energy Commission has carried out several experiments including the mini-INCA (INcineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in {sup 248}Cm ({approx}97 %) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides formations ranged from 0.3% to 1.3%. This uncertainties range is quite acceptable for the nuclear data to be used in transmutation studies.

  7. Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory

    SciTech Connect (OSTI)

    Moody, K J; Shaughnessy, D A; Gostic, J M

    2011-11-29T23:59:59.000Z

    The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and for evaluation of homolog chemical properties. CAMS also offers an environment for testing these systems 'online' by incorporating automated chemical systems into the beamline so that tracers can be created, transported, and chemically separated all on the shorter timescales required for transactinide experiments. Even though CAMS is limited in the types and energies of ions they can accelerate, there are still a wide variety of reactions that can be performed there with commercially available target materials. The half-lives of these isotopes vary over a range that could be used for both online chemistry (where shorter half-lives are required) and benchtop tracers studies (where longer lived isotopes are preferred). In this document, they present a summary of tracer production reactions that could be performed at CAMS, specifically for online, automated chemical studies. They are from chemical groups four through seven, 13, and 14, which would be appropriate for studies of elements 104-107, 113, and 114. Reactions were selected that had (a) commercially available target material, (b) half-lives long enough for transport from a target chamber to an automated chemistry system, and (c) cross-sections at CAMS available projectile energies that were large enough to produce enough atoms to result in a statistically relevant signal after losses for transport and chemistry were considered. In addition, the resulting product atoms had to decay with an observable gamma-ray using standard Ge gamma-ray detectors. The table includes calculations performed for both metal targets and their corresponding oxides.

  8. The Uncertainties in the 22Ne + alpha-capture Reaction Rates and the Production of the Heavy Magnesium Isotopes in Asymptotic Giant Branch Stars of Intermediate Mass

    E-Print Network [OSTI]

    A. Karakas; M. Lugaro; M. Wiescher; J. Goerres; C. Ugalde

    2006-01-27T23:59:59.000Z

    We present new rates for the 22Ne(alpha, n)25Mg and 22Ne(alpha,gamma)26Mg reactions, with uncertainties that have been considerably reduced compared to previous estimates, and we study how these new rates affect the production of the heavy magnesium isotopes in models of intermediate mass Asymptotic Giant Branch (AGB) stars of different initial compositions. All the models have deep third dredge-up, hot bottom burning and mass loss. Calculations have been performed using the two most commonly used estimates of the 22Ne + alpha rates as well as the new recommended rates, and with combinations of their upper and lower limits. The main result of the present study is that with the new rates, uncertainties on the production of isotopes from Mg to P coming from the 22Ne + alpha-capture rates have been considerably reduced. We have therefore removed one of the important sources of uncertainty to effect models of AGB stars. We have studied the effects of varying the mass-loss rate on nucleosynthesis and discuss other uncertainties related to the physics employed in the computation of stellar structure, such as the modeling of convection, the inclusion of a partial mixing zone and the definition of convective borders. These uncertainties are found to be much larger than those coming from 22Ne + alpha-capture rates, when using our new estimates. Much effort is needed to improve the situation for AGB models.

  9. Mass-dependent fractionation of quadruple stable sulfur isotope system as a new tracer of sulfur biogeochemical cycles

    E-Print Network [OSTI]

    Long, Bernard

    - ing rare isotopes for Earth materials was the discovery of anomalous 17 O abundance in a wide variety, USA b Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland and extraterrestrial materials. Ã? 2006 Elsevier Inc. All rights reserved. 1. Introduction Sulfur (32 S, 33 S, 34 S

  10. Standard Test Method for Isotopic Analysis of Uranium Hexafluoride by Single-Standard Gas Source Multiple Collector Mass Spectrometer Method

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2011-01-01T23:59:59.000Z

    1.1 This test method is applicable to the isotopic analysis of uranium hexafluoride (UF6) with 235U concentrations less than or equal to 5 % and 234U, 236U concentrations of 0.0002 to 0.1 %. 1.2 This test method may be applicable to the analysis of the entire range of 235U isotopic compositions providing that adequate Certified Reference Materials (CRMs or traceable standards) are available. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety health practices and determine the applicability of regulatory limitations prior to use.

  11. Development of high through-put Sr isotope analysis for monitoring reservoir integrity for CO{sub 2} storage.

    SciTech Connect (OSTI)

    Wall, Andy; Jain, Jinesh; Stewart, Brian; Capo, Rosemary; Hakala, Alexandra J.; Hammack, Richard; Guthrie, George

    2012-01-01T23:59:59.000Z

    Recent innovations in multi-collector ICP-mass spectrometry (MC-ICP-MS) have allowed for rapid and precise measurements of isotope ratios in geological samples. Naturally occurring Sr isotopes has the potential for use in Monitoring, Verification, and Accounting (MVA) associated with geologic CO2 storage. Sr isotopes can be useful for: Sensitive tracking of brine migration; Determining seal rock leakage; Studying fluid/rock reactions. We have optimized separation chemistry procedures that will allow operators to prepare samples for Sr isotope analysis off site using rapid, low cost methods.

  12. Characterization of Diesel Fuel by Chemical Separation Combined with Capillary Gas Chromatography (GC) Isotope Ratio Mass Spectrometry (IRMS)

    SciTech Connect (OSTI)

    Harvey, Scott D.; Jarman, Kristin H.; Moran, James J.; Sorensen, Christina M.; Wright, Bob W.

    2011-09-15T23:59:59.000Z

    The purpose of this study was to perform a preliminary investigation of compound-specific isotope analysis (CSIA) of diesel fuels to evaluate whether the technique could distinguish between the diesel samples from different sources/locations. The ability to differentiate or correlate diesel samples could be valuable for detecting fuel tax evasion schemes. Two fractionation techniques were used to isolate the n-alkanes from the fuel. Both ?13C and ?D values for the n-alkanes were then determined by CSIA in each sample. Plots of ?D versus ?13C with sample n-alkane points connected in order of increasing carbon number gave well separated clusters with characteristic shapes for each sample. Principal components analysis (PCA) with ?13C, ?D, or combined ?13C and ?D data on the yielded scores plots that could clearly differentiate the samples, thereby demonstrating the potential of this approach for fingerprinting fuel samples using the ?13C and ?D values.

  13. Laser isotope separation

    DOE Patents [OSTI]

    Robinson, C. Paul (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Cotter, Theodore P. (Munich, DE); Boyer, Keith (Los Alamos, NM); Greiner, Norman R. (Los Alamos, NM)

    1988-01-01T23:59:59.000Z

    A process and apparatus for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photolysis, photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photolysis, photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium.

  14. Photochemical isotope separation

    DOE Patents [OSTI]

    Robinson, C. Paul (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Cotter, Theodore P. (Los Alamos, NM); Greiner, Norman R. (Los Alamos, NM); Boyer, Keith (Los Alamos, NM)

    1987-01-01T23:59:59.000Z

    A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

  15. Photochemical isotope separation

    DOE Patents [OSTI]

    Robinson, C.P.; Jensen, R.J.; Cotter, T.P.; Greiner, N.R.; Boyer, K.

    1987-04-28T23:59:59.000Z

    A process is described for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium. 8 figs.

  16. Natural mercury isotope variation in coal deposits and organic soils

    SciTech Connect (OSTI)

    Abir, Biswas; Joel D. Blum; Bridget A. Bergquist; Gerald J. Keeler; Zhouqing Xie [University of Michigan, Ann Arbor, MI (United States). Department of Geological Sciences

    2008-11-15T23:59:59.000Z

    There is a need to distinguish among sources of Hg to the atmosphere in order to more fully understand global Hg pollution. In this study we investigate whether coal deposits within the United States, China, and Russia-Kazakhstan, which are three of the five greatest coal-producing regions, have diagnostic Hg isotopic fingerprints that can be used to discriminate among Hg sources. We also investigate the Hg isotopic composition of modern organic soil horizons developed in areas distant from point sources of Hg in North America. Mercury stored in coal deposits displays a wide range of both mass dependent fractionation and mass independent fractionation. {delta}{sup 202}Hg varies in coals by 3{per_thousand} and {Delta}{sup 201}Hg varies by 0.9{per_thousand}. Combining these two Hg isotope signals results in what may be a unique isotopic 'fingerprint' for many coal deposits. Mass independent fractionation of mercury has been demonstrated to occur during photochemical reactions of mercury. This suggests that Hg found in most coal deposits was subjected to photochemical reduction near the Earth's surface prior to deposition. The similarity in MDF and MIF of modern organic soils and coals from North America suggests that Hg deposition from coal may have imprinted an isotopic signature on soils. This research offers a new tool for characterizing mercury inputs from natural and anthropogenic sources to the atmosphere and provides new insights into the geochemistry of mercury in coal and soils. 35 refs., 2 figs., 1 tab.

  17. Ultimate Isotope Precision for Carbonates Thermo Scientific

    E-Print Network [OSTI]

    Lachniet, Matthew S.

    Ultimate Isotope Precision for Carbonates Thermo Scientific KIEL IV Carbonate Device Part of Thermo integration cycle Ultimate Isotope Precision for Carbonates The Thermo Scientific KIEL IV Carbonate DeviceV Thermo Scientific MAT 253 or the 3-kV DELTA V isotope ratio mass spectrometer meets the requirements

  18. Isotope separation by laser means

    DOE Patents [OSTI]

    Robinson, C. Paul (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Cotter, Theodore P. (Los Alamos, NM); Greiner, Norman R. (Los Alamos, NM); Boyer, Keith (Los Alamos, NM)

    1982-06-15T23:59:59.000Z

    A process for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light. A highly cooled gas of the volatile compound is produced in which the isotopic shift is sharpened and defined. Before substantial condensation occurs, the cooled gas is irradiated with laser light precisely tuned to a desired wavelength to selectively excite a particular isotopic species in the cooled gas. The laser light may impart sufficient energy to the excited species to cause it to undergo photochemical reaction or even to photoionize. Alternatively, a two-photon irradiation may be applied to the cooled gas to induce photochemical reaction or photoionization. The process is particularly applicable to the separation of isotopes of uranium and plutonium.

  19. Search for long-lived isomeric states in neutron-deficient thorium isotopes

    SciTech Connect (OSTI)

    Lachner, J.; Dillmann, I.; Faestermann, T.; Korschinek, G.; Poutivtsev, M.; Rugel, G. [Physik Department E12 and E15, Technische Universitaet Muenchen, D-85748 Garching (Germany)

    2008-12-15T23:59:59.000Z

    The discovery of naturally occurring long-lived isomeric states (t{sub 1/2}>10{sup 8} yr) in the neutron-deficient isotopes {sup 211,213,217,218}Th[A. Marinov et al., Phys. Rev. C 76, 021303(R) (2007)] was reexamined using accelerator mass spectrometry (AMS). Because AMS does not suffer from molecular isobaric background in the detection system, it is an extremely sensitive technique. Despite our up to two orders of magnitude higher sensitivity we cannot confirm the discoveries of neutron-deficient thorium isotopes and provide upper limits for their abundances.

  20. Search for long-lived isomeric states in neutron-deficient thorium isotopes

    E-Print Network [OSTI]

    J. Lachner; I. Dillmann; T. Faestermann; G. Korschinek; M. Poutivtsev; G. Rugel

    2009-07-01T23:59:59.000Z

    The discovery of naturally occurring long-lived isomeric states (t_1/2 > 10^8 yr) in the neutron-deficient isotopes 211,213,217,218Th [A. Marinov et al., Phys. Rev. C 76, 021303(R) (2007)] was reexamined using accelerator mass spectrometry (AMS). Because AMS does not suffer from molecular isobaric background in the detection system, it is an extremely sensitive technique. Despite our up to two orders of magnitude higher sensitivity we cannot confirm the discoveries of neutron-deficient thorium isotopes and provide upper limits for their abundances.

  1. from Isotope Production Facility

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cancer-fighting treatment gets boost from Isotope Production Facility April 13, 2012 Isotope Production Facility produces cancer-fighting actinium 2:32 Isotope cancer treatment...

  2. Z=50 shell gap near $^{100}$Sn from intermediate-energy Coulomb excitations in even-mass $^{106--112}$Sn isotopes

    E-Print Network [OSTI]

    C. Vaman; C. Andreoiu; D. Bazin; A. Becerril; A. Brown; C. M. Campbell; A. Chester; J. M. Cook; D. C. Dinca; A. Gade; D. Galaviz; T. Glasmacher; M. Hjorth-Jensen; M. Horoi; D. Miller; V. Moeller; W. F. Mueller; A. Schiller; K. Starosta; A. Stolz; J. R. Terry; A. Volya; V. Zelevinsky; H. Zwahlen

    2006-12-08T23:59:59.000Z

    Rare isotope beams of neutron-deficient $^{106,108,110}$Sn nuclei from the fragmentation of $^{124}$Xe were employed in an intermediate-energy Coulomb excitation experiment yielding $B(E2, 0^+_1 \\to 2^+_1)$ transition strengths. The results indicate that these $B(E2,0^+_1 \\to 2^+_1)$ values are much larger than predicted by current state-of-the-art shell model calculations. This discrepancy can be explained if protons from within the Z = 50 shell are contributing to the structure of low-energy excited states in this region. Such contributions imply a breaking of the doubly-magic $^{100}$Sn core in the light Sn isotopes.

  3. acfa isotope activation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    N. Densmore a, Geosciences Websites Summary: -occur- ring radioactive isotopes such as uranium, and radium also have Maximum Contaminant Levels (MCL and 25 picoCuries per liter...

  4. Positive and inverse isotope effect on superconductivity

    E-Print Network [OSTI]

    Tian De Cao

    2009-09-04T23:59:59.000Z

    This article improves the BCS theory to include the inverse isotope effect on superconductivity. An affective model can be deduced from the model including electron-phonon interactions, and the phonon-induced attraction is simply and clearly explained on the electron Green function. The focus of this work is on how the positive or inverse isotope effect occurs in superconductors.

  5. Isotopically controlled semiconductors

    E-Print Network [OSTI]

    Haller, Eugene E.

    2006-01-01T23:59:59.000Z

    16 Isotopically Controlled Semiconductors Eugene E. Hallerof isotopically engineered semiconductors; for outstandingisotopically controlled semiconductor crystals. This article

  6. Physics with isotopically controlled semiconductors

    SciTech Connect (OSTI)

    Haller, E. E., E-mail: eehaller@lbl.gov [University of California at Berkeley, Department of Materials Science and Engineering (United States)

    2010-07-15T23:59:59.000Z

    This paper is based on a tutorial presentation at the International Conference on Defects in Semiconductors (ICDS-25) held in Saint Petersburg, Russia in July 2009. The tutorial focused on a review of recent research involving isotopically controlled semiconductors. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, is the most prominent effect for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples.

  7. Stable Isotope Signatures for Microbial Forensics

    SciTech Connect (OSTI)

    Kreuzer, Helen W.

    2012-01-03T23:59:59.000Z

    The isotopic distribution of the atoms composing the molecules of microorganisms is a function of the substrates used by the organisms. The stable isotope content of an organism is fixed so long as no further substrate consumption and biosynthesis occurs, while the radioactive isotopic content decays over time. The distribution of stable isotopes of C, N, O and H in heterotrophic microorganisms is a direct function of the culture medium, and therefore the stable isotope composition can be used to associate samples with potential culture media and also with one another. The 14C content depends upon the 14C content, and therefore the age, of the organic components of the culture medium, as well as on the age of the culture itself. Stable isotope signatures can thus be used for sample matching, to associate cultures with specific growth media, and to predict characteristics of growth media.

  8. {sup 99}Tc bioassay: A direct comparison of liquid scintillation radiation detection and ICP-MS mass detection of the {sup 99}Tc isotope

    SciTech Connect (OSTI)

    Lewis, L.A. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States). Analytical Services Organization; Schweitzer, G.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry

    1998-12-31T23:59:59.000Z

    A means of analyzing {sup 99}Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, {sup 99}Tc analysis was based on the radiometric detection of the 293 keV E{sub Max.} beta decay product by liquid scintillation or gas flow proportional counting. A separation scheme for {sup 99}Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of {sup 99}Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard manual quench correction and an automatic quench curve correction method are compared with results obtained by ICP-MS. Each method produced accurate results; however, the precision of the ICP-MS results is superior to that of liquid scintillation results.

  9. Isotope-labeled immunoassays without radiation waste

    E-Print Network [OSTI]

    Hammock, Bruce D.

    of California, Davis, CA 95616; and Center for Accelerator Mass Spectrometry, Lawrence Livermore National, such as liquid scintillation counting (LSC) and autoradiography, use the radiation generated in the isotope in areas such as environmental monitoring and food analysis. Accelerator mass spectrometry (AMS) developed

  10. Triple Oxygen Isotope Measurement of Nitrate to Analyze Impact of Aircraft Emissions

    E-Print Network [OSTI]

    Chan, Sharleen

    P. ; Craig, H. Atmospheric oxygen: isotopic composition andM.H. 1986. A non-mass-dependent oxygen isotope effect in theof ozone from molecular oxygen: the role of symmetry in

  11. Comparison of isotopic transmutation modelling codes

    E-Print Network [OSTI]

    Beard, Carl Allen

    1990-01-01T23:59:59.000Z

    . Numerical solutions to the equations that govern isotopic transmutation can be obtained in several ways. Each method possesses a certain amount of intrinsic error which is inherent in the solution scheme, but which can also vary depending upon... of the removed nuclide if it falls between two long-lived isotopes, or by adding the initial concentration of the short-lived isotope to the first long-lived nuclide which occurs in the production chain. In this second case, the final contribution from...

  12. Isotope Science and Production

    E-Print Network [OSTI]

    Isotope Science and Production 35 years of experience in isotope production, processing, and applications. Llllll Committed to the safe and reliable production of radioisotopes, products, and services nuclear materials in trucks and cargo containers. Isotopes for Threat Reduction Isotope production at Los

  13. Stable isotope studies

    SciTech Connect (OSTI)

    Ishida, T.

    1992-01-01T23:59:59.000Z

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  14. Method for enriching a middle isotope using vibration-vibration pumping

    DOE Patents [OSTI]

    Rich, Joseph W. (East Aurora, NY); Homicz, Gregory F. (Getzville, NY); Bergman, Richard C. (Corfu, NY)

    1989-01-01T23:59:59.000Z

    Method for producing isotopically enriched material by vibration-vibration excitation of gaseous molecules wherein a middle mass isotope of an isotopic mixture including lighter and heavier mass isotopes preferentially populates a higher vibrational mode and chemically reacts to provide a product in which it is enriched. The method can be used for vibration-vibration enrichment of .sup.17 O in a CO reactant mixture.

  15. Analysis of hydrogen isotope mixtures

    DOE Patents [OSTI]

    Villa-Aleman, Eliel (Aiken, SC)

    1994-01-01T23:59:59.000Z

    An apparatus and method for determining the concentrations of hydrogen isotopes in a sample. Hydrogen in the sample is separated from other elements using a filter selectively permeable to hydrogen. Then the hydrogen is condensed onto a cold finger or cryopump. The cold finger is rotated as pulsed laser energy vaporizes a portion of the condensed hydrogen, forming a packet of molecular hydrogen. The desorbed hydrogen is ionized and admitted into a mass spectrometer for analysis.

  16. Level structure of the odd mass Pr isotopes. III. Levels of [sup 147]Pr[sub 88] populated in the beta decay of 56-s [sup 147]Ce

    SciTech Connect (OSTI)

    Mantica, P.F. (Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742 (United States) UNISOR, Oak Ridge Institute for Science Education, Oak Ridge, Tennessee 37831 (United States)); Robertson, J.D.; Baum, E.M.; Walters, W.B. (Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742 (United States))

    1993-10-01T23:59:59.000Z

    The structure of [sup 147]Pr has been investigated by performing measurements of [gamma]-ray and conversion-electron singles and [gamma][gamma] coincidence spectra of mass separated sources of 56-s [sup 147]Ce. The proposed level scheme extends the known structure of [sup 147]Pr to an energy of 2.2 MeV and includes several levels below 1.2 MeV that have not been identified in previous decay studies of [sup 147]Ce. Measurement of the conversion coefficients for several transitions has led to the assignment of negative parity to the levels at 362, 452, 467, and 608 keV in [sup 147]Pr, which show properties similar to low-energy negative-parity states identified in [sup 145]Pr[sub 86], [sup 145]La[sub 88], and [sup 149]Pm[sub 88]. The presence of low-energy negative-parity states suggests that configurations having significantly different deformation, related to the highly deformed region above [ital N]=90 and/or to the reflection asymmetric region identified around [sup 145]Ba, may manifest themselves at low energy in these nuclides.

  17. Coastal and Marine Nitrogen Sources Shift Isotopic Baselines in Pelagic Food Webs of the Gulf of Mexico

    E-Print Network [OSTI]

    Dorado, Samuel

    2012-07-16T23:59:59.000Z

    variability to the degree of freshwater influence. Published food web data from these two environments were then assessed to establish whether isotopic baseline shifts observed in our data occur at an ecosystem level. Isotope values of the POM...

  18. The Isotopic Abundances of Magnesium in Stars

    E-Print Network [OSTI]

    Pamela Gay; David L. Lambert

    1999-11-11T23:59:59.000Z

    Isotopic abundance ratios 24^Mg:25^Mg:26^Mg are derived for 20 stars from high- resolution spectra of the MgH A-X 0-0 band at 5140AA. With the exception of the weak g-band giant HR 1299, the stars are dwarfs that sample the metallicity range -1.8 < [Fe/H] <0.0. The abundance of 25^Mg amd 26^Mg relative to the dominant isotope 24^Mg decreases with decreasing [Fe/H] in fair accord with predictions from a recent model of galactic chemical evolution in which the Mg isotopes are synthesised by massive stars. Several stars appear especially enriched in the heavier Mg isotopes suggesting contamination by material from the envelopes of intermediate-mass AGB stars.

  19. A direct and rapid leaf water extraction method for isotopic analysis

    E-Print Network [OSTI]

    Yakir, Dan

    Department of Environmental Sciences and Energy Research, Weizmann Institute of Science, Rehovot, Israel for isotopic analysis via pyrolysis gas chromatography isotope ratio mass spectrometry (PYR/GC/IRMS). The new-scale studies that require high-throughput leaf water isotopic analysis. Copyright # 2008 John Wiley & Sons, Ltd

  20. Using phylogenetic probes for quantification of stable isotope labeling and microbial community analysis

    DOE Patents [OSTI]

    Brodie, Eoin L; DeSantis, Todd Z; Karaoz, Ulas; Andersen, Gary L

    2014-12-09T23:59:59.000Z

    Herein is described methods for a high-sensitivity means to measure the incorporation of stable isotope labeled substrates into RNA following stable isotope probing experiments (SIP). RNA is hybridized to a set of probes such as phylogenetic microarrays and isotope incorporation is quantified such as by secondary ion mass spectrometer imaging (NanoSIMS).

  1. Evidence of magnetic isotope effects during thermochemical sulfate reduction

    E-Print Network [OSTI]

    Oduro, Harry D.

    Thermochemical sulfate reduction experiments with simple amino acid and dilute concentrations of sulfate reveal significant degrees of mass-independent sulfur isotope fractionation. Enrichments of up to 13‰ for [superscript ...

  2. argon isotope analysis: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1.1 This is a quantitative test method applicable to determining the mass percent of uranium isotopes in uranium hexafluoride (UF6) samples with 235U concentrations between 0.1...

  3. Resolving the stellar sources of isotopically rare presolar silicate grains through Mg and Fe isotopic analyses

    SciTech Connect (OSTI)

    Nguyen, Ann N.; Messenger, Scott, E-mail: lan-anh.n.nguyen@nasa.gov [Robert M. Walker Laboratory for Space Science, Astromaterials Research and Exploration Science Directorate, NASA Johnson Space Center, Houston, TX 77058 (United States)

    2014-04-01T23:59:59.000Z

    We conducted multi-element isotopic analyses of 11 presolar silicate grains from the Acfer 094 meteorite having unusual O isotopic compositions. Eight grains are {sup 18}O-rich, one is {sup 16}O-rich, and two are extremely {sup 17}O-rich. We constrained the grains' stellar sources by measuring their Si and Mg isotopic ratios, and also the {sup 54}Fe/{sup 56}Fe and {sup 57}Fe/{sup 56}Fe ratios for five grains. The Mg and Fe isotopic measurements were conducted after surrounding matrix grains were removed for more accurate ratios. Most of the {sup 18}O-rich silicates had anomalous Mg isotopic ratios, and their combined isotopic constraints are consistent with origins in low-mass Type II supernovae (SNe II) rather than high-metallicity stars. The isotopic ratios of the {sup 16}O-rich silicate are also consistent with an SN origin. Mixing small amounts of interior stellar material with the stellar envelope replicated all measured isotopic ratios except for {sup 29}Si/{sup 28}Si and {sup 54}Fe/{sup 56}Fe in some grains. The {sup 29}Si/{sup 28}Si ratios of all SN-derived grains are matched by doubling the {sup 29}Si yield in the Ne- and Si-burning zones. The {sup 54}Fe/{sup 56}Fe ratios of the grains imply elemental fractionation in the Si/S zone, or introduction of isotopically solar Fe by secondary processing. The two highly {sup 17}O-rich silicates exhibited significant {sup 25}Mg and/or {sup 26}Mg enrichments and their isotopic ratios are best explained by strong dilution of 1.15 M {sub ?} CO nova matter. We estimate that ?12% and 1% of presolar silicates have SN and nova origins, respectively, similar to presolar SiC and oxides. This implies that asymptotic giant branch stars are the dominant dust producers in the galaxy.

  4. Naturally Occurring Radioactive Materials in Cargo at US Borders

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Ely, James H.; Evans, John C.; Hensley, Walter K.; Lepel, Elwood A.; McDonald, Joseph C.; Schweppe, John E.; Siciliano, Edward R.; Strom, Daniel J.; Woodring, Mitchell L.

    2006-01-01T23:59:59.000Z

    In the U.S. and other countries, large numbers of vehicles pass through border crossings each day. The illicit movement of radioactive sources is a concern that has resulted in the installation of radiation detection and identification instruments at border crossing points. This activity is judged to be necessary because of the possibility of an act of terrorism involving a radioactive source that may include any number of dangerous radionuclides. The problem of detecting, identifying, and interdicting illicit radioactive sources is complicated by the fact that many materials present in cargo are somewhat radioactive. Some cargo contains naturally occurring radioactive material or technologically-enhanced naturally occurring radioactive material that may trigger radiation portal monitor alarms. Man-made radioactive sources, especially medical isotopes, are also frequently observed and produce alarms. Such nuisance alarms can be an operational limiting factor for screening of cargo at border crossings. Information about the nature of the radioactive materials in cargo that can interfere with the detection of radionuclides of concern is necessary. This paper provides such information for North American cargo, but the information may also be of use to border control officials in other countries. (PIET-43741-TM-361)

  5. Laser isotope separation by multiple photon absorption

    DOE Patents [OSTI]

    Robinson, C. Paul (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM); Jensen, Reed J. (Los Alamos, NM); Lyman, John L. (Los Alamos, NM); Aldridge, III, Jack P. (Los Alamos, NM)

    1987-01-01T23:59:59.000Z

    Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, is the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO.sub.2 laser light may be used to highly enrich .sup.34 S in natural SF.sub.6 and .sup.11 B in natural BCl.sub.3.

  6. Laser isotope separation by multiple photon absorption

    DOE Patents [OSTI]

    Robinson, C.P.; Rockwood, S.D.; Jensen, R.J.; Lyman, J.L.; Aldridge, J.P. III.

    1987-04-07T23:59:59.000Z

    Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, is the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO[sub 2] laser light may be used to highly enrich [sup 34]S in natural SF[sub 6] and [sup 11]B in natural BCl[sub 3]. 8 figs.

  7. Hybrid isotope separation scheme

    DOE Patents [OSTI]

    Maya, J.

    1991-06-18T23:59:59.000Z

    A method is described for yielding selectively a desired enrichment in a specific isotope including the steps of inputting into a spinning chamber a gas from which a scavenger, radiating the gas with a wave length or frequency characteristic of the absorption of a particular isotope of the atomic or molecular gas, thereby inducing a photochemical reaction between the scavenger, and collecting the specific isotope-containing chemical by using a recombination surface or by a scooping apparatus. 2 figures.

  8. Hybrid isotope separation scheme

    DOE Patents [OSTI]

    Maya, Jakob (Brookline, MA)

    1991-01-01T23:59:59.000Z

    A method of yielding selectively a desired enrichment in a specific isotope including the steps of inputting into a spinning chamber a gas from which a scavenger, radiating the gas with a wave length or frequency characteristic of the absorption of a particular isotope of the atomic or molecular gas, thereby inducing a photochemical reaction between the scavenger, and collecting the specific isotope-containing chemical by using a recombination surface or by a scooping apparatus.

  9. Stable isotope enrichment

    ScienceCinema (OSTI)

    Egle, Brian

    2014-07-15T23:59:59.000Z

    Brian Egle is working to increase the nation's capacity to produce stable isotopes for use including medicine, industry and national security.

  10. Isotopically controlled semiconductors

    E-Print Network [OSTI]

    Haller, E.E.

    2004-01-01T23:59:59.000Z

    and phonons in semiconductors,” J. Non-Cryst. Solids 141 (LVM) Spectroscopy of Semiconductors,” Mat. Res. Soc. Symp.Isotopically Engineered Semiconductors – New Media for the

  11. Stable isotope enrichment

    SciTech Connect (OSTI)

    Egle, Brian

    2014-07-14T23:59:59.000Z

    Brian Egle is working to increase the nation's capacity to produce stable isotopes for use including medicine, industry and national security.

  12. CAN GALACTIC CHEMICAL EVOLUTION EXPLAIN THE OXYGEN ISOTOPIC VARIATIONS IN THE SOLAR SYSTEM?

    SciTech Connect (OSTI)

    Lugaro, Maria [Monash Centre for Astrophysics (MoCA), Building 28, Monash University, Clayton, VIC 3800 (Australia); Liffman, Kurt [CSIRO/MSE, P.O. Box 56, Highett, VIC 3190 (Australia); Ireland, Trevor R. [Planetary Science Institute and Research School of Earth Sciences, Australian National University, Canberra, ACT 0200 (Australia); Maddison, Sarah T., E-mail: maria.lugaro@monash.edu [Centre for Astrophysics and Supercomputing, Swinburne University, H39, P.O. Box 218, Hawthorn, VIC 3122 (Australia)

    2012-11-01T23:59:59.000Z

    A number of objects in primitive meteorites have oxygen isotopic compositions that place them on a distinct, mass-independent fractionation line with a slope of one on a three-isotope plot. The most popular model for describing how this fractionation arose assumes that CO self-shielding produced {sup 16}O-rich CO and {sup 16}O-poor H{sub 2}O, where the H{sub 2}O subsequently combined with interstellar dust to form relatively {sup 16}O-poor solids within the solar nebula. Another model for creating the different reservoirs of {sup 16}O-rich gas and {sup 16}O-poor solids suggests that these reservoirs were produced by Galactic chemical evolution (GCE) if the solar system dust component was somewhat younger than the gas component and both components were lying on the line of slope one in the O three-isotope plot. We argue that GCE is not the cause of mass-independent fractionation of the oxygen isotopes in the solar system. The GCE scenario is in contradiction with observations of the {sup 18}O/{sup 17}O ratios in nearby molecular clouds and young stellar objects. It is very unlikely for GCE to produce a line of slope one when considering the effect of incomplete mixing of stellar ejecta in the interstellar medium. Furthermore, the assumption that the solar system dust was younger than the gas requires unusual timescales or the existence of an important stardust component that is not theoretically expected to occur nor has been identified to date.

  13. Discovery of the Tungsten Isotopes

    E-Print Network [OSTI]

    A. Fritsch; J. Q. Ginepro; M. Heim; A. Schuh; A. Shore; M. Thoennessen

    2009-03-25T23:59:59.000Z

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  14. Discovery of the Titanium Isotopes

    E-Print Network [OSTI]

    D. Meierfrankenfeld; M. Thoennessen

    2010-09-08T23:59:59.000Z

    Twentyfive titanium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  15. Discovery of the Tin Isotopes

    E-Print Network [OSTI]

    S. Amos; M. Thoennessen

    2010-09-08T23:59:59.000Z

    Thirty-eight tin isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  16. Discovery of the tungsten isotopes

    SciTech Connect (OSTI)

    Fritsch, A.; Ginepro, J.Q.; Heim, M.; Schuh, A.; Shore, A. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Thoennessen, M. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)], E-mail: thoennessen@nscl.msu.edu

    2010-05-15T23:59:59.000Z

    Thirty-five tungsten isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  17. Discovery of the Tungsten Isotopes

    E-Print Network [OSTI]

    Fritsch, A; Heim, M; Schuh, A; Shore, A; Thoennessen, M

    2009-01-01T23:59:59.000Z

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  18. Hyperfiltration-induced fractionation of lithium isotopes in geologic systems. Progress report, April 1, 1991--December 1, 1991

    SciTech Connect (OSTI)

    Fritz, S.J.

    1992-01-01T23:59:59.000Z

    Effective modeling of hyperfiltration-induced fractionation of lithium isotopes is hindered by a lack of data on aqueous diffusion coefficients of {sup 6}Li{sup +} and {sup 7}Li{sup +}. Several experiments were conducted this past year on yielded a value for the ratio of diffusion coefficients between {sup D6}Li+Cl{minus}/{sup D7}Li+Cl{minus}. A 0.9450 M LiCl solution was placed within sealed dialysis tubing and osmoted against a kilogram of deionized water at 22C. Osmotic equilibrium occurred at 143 minutes, and the ratio of {omega}{sup 6}Li{sup +}Cl{minus}/{omega}{sup 7}Li+Cl{minus} was measured to be 1.011. Because this experimental value is close to the square root of the mass ratio between {sup 7}LiCl and {sup 6}LiCl (1.012), Graham`s Law may be a convenient way to calculate such ratios for aqueous diffusion coefficients of individual isotopic components. In evolution of this closed-system osmotic cell as a function of time, Li isotopic ratios of beaker and bag solutions exhibit a minimum and a maximum before the {sup 6}Li/{sup 7}Li ratios of both solutions assume the inevitable asymptotic approach toward isotopic equilibrium. Max difference in {sup 6}Li/{sup 7}Li ratio between beaker and bag solution was 0.00156 {plus_minus} 0.00015.

  19. (Carbon isotope fractionation inplants)

    SciTech Connect (OSTI)

    O'Leary, M.H.

    1990-01-01T23:59:59.000Z

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  20. Characterization of naturally occurring porous media

    E-Print Network [OSTI]

    Riley, Robert Daniel

    1965-01-01T23:59:59.000Z

    characteristics of natural occur- ring porous media, The gR /K dimensionless ratio is related to the minimum water saturation in the reverse manner as is permeability. REFERENCES Wyllie, M. R. J. and M. B. Spangler: Application of Electrical Resistivity...: Resistivity of Brine-Saturated Sands in Relation to Pore Seometry. Cornell, D. snd D. L. Kstz: Flow of Sases through Consolidated Porous Media. Industrial and En ineeri hemietr (October 1953) Vo . 5, p. 21 5. Leverett, N, C. : Capillary Behavior...

  1. High precision analysis of all four stable isotopes of sulfur S) at nanomole levels using a laser fluorination

    E-Print Network [OSTI]

    Long, Bernard

    compositions. This methodology increases the spatial resolution of the laser ablation in situ analysis) at nanomole levels using a laser fluorination isotope-ratio-monitoring gas chromatography­mass spectrometry.V. All rights reserved. Keywords: S-33; S-36; Sulfur isotope; Laser; Isotope analysis; Continuous flow

  2. Existence of long-lived isotopes of a superheavy element in natural Au

    E-Print Network [OSTI]

    A. Marinov; I. Rodushkin; A. Pape; Y. Kashiv; D. Kolb; R. Brandt; R. V. Gentry; H. W. Miller; L. Halicz; I. Segal

    2007-02-25T23:59:59.000Z

    Evidence for the existence of long-lived isotopes with atomic mass numbers 261 and 265 and abundance of (1-10)x10$^{-10}$ relative to Au has been found in a study of natural Au using an inductively coupled plasma - sector field mass spectrometer. The measured masses fit the predictions made for the masses of $^{261}$Rg and $^{265}$Rg (Z=111) and for some isotopes of nearby elements. The possibility that these isotopes belong to the recently discovered class of long-lived high spin super- and hyperdeformed isomeric states is discussed.

  3. Time-of-Flight Mass Measurements of Exotic Nuclei

    SciTech Connect (OSTI)

    Matos, M. [Michigan State Univ./JINA/Louisiana State University; Estrade, A. [Michigan State Univ./JINA/LSU/Saint Mary's Univ./GSI Darmstadt, GE; Schatz, H. [Michigan State Univ./JINA; Bazin, D. [Michigan State University, East Lansing; Famiano, M. [Western Michigan University, Kalamazoo; Gade, A. [Michigan State University, East Lansing; George, S. [NSCL, Michigan State University, East Lansing; Lynch, W. G. [NSCL, Michigan State Univ./JINA; Meisel, Z. [NSCL, Michigan State Univ./JINA; Portillo, M. [NSCL, Michigan State University, East Lansing; Rogers, A. [NSCL, Michigan State Univ./JINA; Shapira, Dan [ORNL; Stolz, A. [Michigan State University, East Lansing; Wallace, M. [Los Alamos National Laboratory (LANL); Yurkon, J. [NSCL, Michigan State University, East Lansing

    2012-01-01T23:59:59.000Z

    Atomic masses play an important role in nuclear physics and astrophysics. The need of experimental mass values for unstable nuclides has triggered the development of a wide range of mass measurement techniques, with devices installed at many laboratories around the world. We have implemented a time-of-flight magnetic-rigidity (TOF-B ) technique at the National Superconducting Cyclotron Laboratory (NSCL) that includes a position measurement for magnetic rigidity corrections and uses the A1900 separator and the S800 spectrograph. We performed a successful first experiment measuring masses of neutron-rich isotopes in the region of Z 20 30, important for calculations of processes occurring in the crust of accreting neutron stars. The masses of 16 nuclei were determined, for 61V, 63Cr, 66Mn, and 74Ni for the first time, with atomic mass excesses of 30.510(890) MeV, 35.280(650) MeV, 36.900(790) MeV, and 49.210(990) MeV, respectively. The mass resolution achieved was 1.8 10 4.

  4. Accelerator mass spectrometry as a bioanalytical tool for nutritional research

    SciTech Connect (OSTI)

    Vogel, J.S.; Turteltaub, K.W.

    1997-09-01T23:59:59.000Z

    Accelerator Mass Spectrometry is a mass spectrometric method of detecting long-lived radioisotopes without regard to their decay products or half-life. The technique is normally applied to geochronology, but recently has been developed for bioanalytical tracing. AMS detects isotope concentrations to parts per quadrillion, quantifying labeled biochemicals to attomole levels in milligram- sized samples. Its advantages over non-isotopeic and stable isotope labeling methods are reviewed and examples of analytical integrity, sensitivity, specificity, and applicability are provided.

  5. High-purity, isotopically enriched bulk silicon

    E-Print Network [OSTI]

    2004-01-01T23:59:59.000Z

    Russia. The stated isotope enrichments are summarized inenrichments >99% have been achieved for each isotope andthe enrichment is highest, are presented. isotope at. % nat.

  6. Introduction to naturally occurring radioactive material

    SciTech Connect (OSTI)

    Egidi, P.

    1997-08-01T23:59:59.000Z

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose-based standards. So when is TENORM a problem? Where is it a problem? That depends on when, where, and whom you talk to! We will start by reviewing background radioactivity, then we will proceed to the geology, mobility, and variability of these radionuclides. We will then review some of the industrial sectors affected by TENORM, followed by a brief discussion on regulatory aspects of the issue.

  7. Isotope shifts in francium isotopes Fr 206 - 213 and Fr 221

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Collister, R.; Gwinner, G.; Tandecki, M.; Behr, J. A.; Pearson, M. R.; Zhang, J.; Orozco, L. A.; Aubin, S.; Gomez, E.; FrPNC Collaboration

    2014-11-01T23:59:59.000Z

    We present the isotope shifts of the 7s1/2 to 7p1/2 transition for francium isotopes ²???²¹³Fr with reference to ²²¹Fr collected from two experimental periods. The shifts are measured on a sample of atoms prepared within a magneto-optical trap by a fast sweep of radio-frequency sidebands applied to a carrier laser. King plot analysis, which includes literature values for 7s1/2 to 7p3/2 isotope shifts, provides a field shift constant ratio of 1.0520(10) and a difference between the specific mass shift constants of 170(100) GHz amu between the D? and D? transitions, of sufficient precision to differentiate between ab initio calculations.

  8. How low-energy fusion can occur

    E-Print Network [OSTI]

    B. Ivlev

    2012-12-04T23:59:59.000Z

    Fusion of two deuterons of room temperature energy is discussed. The nuclei are in vacuum with no connection to any external source (electric or magnetic field, illumination, surrounding matter, traps, etc.) which may accelerate them. The energy of two nuclei is conserved and remains small during the motion through the Coulomb barrier. The penetration through this barrier, which is the main obstacle for low-energy fusion, strongly depends on a form of the incident flux on the Coulomb center at large distances from it. In contrast to the usual scattering, the incident wave is not a single plane wave but the certain superposition of plane waves of the same energy and various directions, for example, a convergent conical wave. The wave function close to the Coulomb center is determined by a cusp caustic which is probed by de Broglie waves. The particle flux gets away from the cusp and moves to the Coulomb center providing a not small probability of fusion (cusp driven tunneling). Getting away from a caustic cusp also occurs in optics and acoustics.

  9. The effects of post-condensation exchange on the isotopic composition of water in1 the atmosphere2

    E-Print Network [OSTI]

    Field, Robert

    of the water vapor and the amount of previous2 rainfall from the air mass as the dominant controls on the isotopic composition of3 atmospheric moisture. These formed the basis of the Rayleigh distillation model4 16 O, causing the progressive8 isotopic depletion of the air mass at it loses moisture. In its most

  10. Evaluation of the isotopic equilibrium between lactate and pyruvate

    SciTech Connect (OSTI)

    Wolfe, R.R.; Jahoor, F.; Miyoshi, H. (Univ. of Texas Medical Branch, Galveston (USA))

    1988-04-01T23:59:59.000Z

    When an isotopic tracer is infused for the purpose of determining the rate of turnover or oxidation of a substrate, it is assumed that the resulting isotopic enrichment of the trace will reflect kinetics of only the pool of interest. However, this may not be the case when carbon-labeled lactate is infused, since rapid isotopic exchange with the intracellular pyruvate and alanine pools could potentially occur. Therefore the authors have determined the extent of isotopic exchange occurring during the infusion of (3-{sup 13}C)lactate into six anesthetized dogs. In the steady state, pyruvate enrichment was 91 {plus minus} 2.2% of the lactate enrichment, and alanine enrichment was 81 {plus minus} 3.3% of the pyruvate enrichment and 72 {plus minus} 2.6% of the lactate enrichment. In contrast, when (3-{sup 13}C)alanine was infused, pyruvate (and lactate) enrichment was 9.9% of the alanine enrichment. They therefore conclude that there is rapid isotopic equilibration between lactate and pyruvate but that interaction with alanine reflects the true metabolic flux rates, rather than isotopic exchange. Consequently, lactate kinetics, as traditionally determined, more accurately reflect whole body pyruvate kinetics.

  11. Transportation of medical isotopes

    SciTech Connect (OSTI)

    Nielsen, D.L.

    1997-11-19T23:59:59.000Z

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document.

  12. VOLUME 83, NUMBER 2 P H Y S I C A L R E V I E W L E T T E R S 12 JULY 1999 Carbon Isotope Effect in Single-Crystal Rb3C60

    E-Print Network [OSTI]

    Fuhrer, Michael S

    abundance and 99% 13 C-enriched Rb3C60 reveal the carbon isotope effect with unprecedented accuracy have similar (99%) isotopic enrichment. Time-of-flight mass spectrometry and secondary-ion mass spectrometry verified the purity and isotopic enrichment of the C60. Vapor transport from C60 powder using

  13. Modeling atmospheric stable water isotopes and the potential for constraining cloud processes and

    E-Print Network [OSTI]

    a significant part of the observed offset from pure Rayleigh distillation. Isotope fields are shown cycle. These ratios are primarily affected by the fractionation occurring at changes of phase

  14. alpha particle-emitting isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    -occur- ring radioactive isotopes such as uranium, and radium also have Maximum Contaminant Levels (MCL and 25 picoCuries per liter (pCiL). Although activities were below the...

  15. 7, 1271512750, 2007 Hydrogen isotope

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    imply that there must be a very strong concomitant isotopic enrichment in the radical channel (CH2O + hACPD 7, 12715­12750, 2007 Hydrogen isotope fractionation in the photolysis of formaldehyde T. S a Creative Commons License. Atmospheric Chemistry and Physics Discussions Hydrogen isotope fractionation

  16. Determination of isotopic thorium in biological samples by combined alpha spectrometry and neutron activation analysis.

    SciTech Connect (OSTI)

    Glover, S. E. (Samuel E.)

    2003-01-01T23:59:59.000Z

    Thorium is a naturally occurring element for whom all isotopes are radioactive . Many of these isotopes are alpha emitting radionuclides, some of which have limits for inhalation lower than plutonium in current regulations . Neutron activation analysis can provide for the low-level determination of 232Th but can not determine other isotopes of dosimetric importance . Biological and environmental samples often have large quantities of materials which activate strongly, limiting the capabilities of instrumental neutron activiation analysis . This paper will discuss the application of a combined technique using alpha spectrometry and radiochemical neutron activiation analysis for the determination of isotopic thorium .

  17. andliquid chromatography-tandem mass: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    using isotope dilution high performance liquid chromatography-tandem mass spectrometry. Open Access Theses and Dissertations Summary: ??A method has been developed for...

  18. High-Precision Measurements of [superscript 33]S and [superscript 34]S Fractionation during SO[subscript 2] Oxidation Reveal Causes of Seasonality in SO[subscript 2] and Sulfate Isotopic Composition

    E-Print Network [OSTI]

    Harris, Eliza

    This study presents high-precision isotope ratio-mass spectrometric measurements of isotopic fractionation during oxidation of SO[subscript 2] by OH radicals in the gas phase and H[subscript 2]O[subscript 2] and transition ...

  19. An algorithm for U-Pb isotope dilution data reduction and uncertainty propagation

    E-Print Network [OSTI]

    McLean, Noah Morgan

    High-precision U-Pb geochronology by isotope dilution-thermal ionization mass spectrometry is integral to a variety of Earth science disciplines, but its ultimate resolving power is quantified by the uncertainties of ...

  20. An algorithm for U-Pb isotope dilution data reduction and uncertainty propagation

    E-Print Network [OSTI]

    McLean, Noah M.; Bowring, J.F.; Bowring, S.A.

    2011-06-01T23:59:59.000Z

    High-precision U-Pb geochronology by isotope dilution-thermal ionization mass spectrometry is integral to a variety of Earth science disciplines, but its ultimate resolving power is quantified by the uncertainties of ...

  1. Candidate processes for diluting the {sup 235}U isotope in weapons-capable highly enriched uranium

    SciTech Connect (OSTI)

    Snider, J.D.

    1996-02-01T23:59:59.000Z

    The United States Department of Energy (DOE) is evaluating options for rendering its surplus inventories of highly enriched uranium (HEU) incapable of being used to produce nuclear weapons. Weapons-capable HEU was earlier produced by enriching uranium in the fissile {sup 235}U isotope from its natural occurring 0.71 percent isotopic concentration to at least 20 percent isotopic concentration. Now, by diluting its concentration of the fissile {sup 235}U isotope in a uranium blending process, the weapons capability of HEU can be eliminated in a manner that is reversible only through isotope enrichment, and therefore, highly resistant to proliferation. To the extent that can be economically and technically justified, the down-blended uranium product will be made suitable for use as commercial reactor fuel. Such down-blended uranium product can also be disposed of as waste if chemical or isotopic impurities preclude its use as reactor fuel.

  2. Exploration of the neutron-rich mass surface from sup 11 Li to sup 66 Fe

    SciTech Connect (OSTI)

    Vieira, D.J.; Wouters, J.M.; Butler, G.W. (Los Alamos National Lab., NM (United States)); Seifert, H.L. (Los Alamos National Lab., NM (United States) Giessen Univ. (Germany). 2. Physikalisches Inst.); Zhou, Z.Y. (Los Alamos National Lab., NM (United States) Nanjing Univ., JS (China). Dept. of Physics and Astronomy); Zhou, X.G.; Tu, X.L.; Lind, V.G. (Utah State Univ., Logan, UT (United States). Dept.

    1991-01-01T23:59:59.000Z

    A small revolution in our ability to perform mass measurements of light-mass, neutron-rich nuclei has occurred during the last five years with the extension of the direct, total mass measurement method to fast recoiling nuclei. To date the work of two groups, one using the SPEG spectrometer at GANIL and the other using the TOFI spectrometer at LAMPF, has yielded over 85 mass measurements of which 62 had not been reported previously. Extending from the neutron-halo nucleus {sup 11}Li up to {sup 66}Fe, a region relevant to the astrophysical r-process, these measurements have provided a valuable first glimpse into the interesting nuclear structure present in many of these exotic nuclei. Herein we highlight the nuclear structure insight which as been gained from these measurements, especially that learned from a comparison to recent shell model calculations. Attention is given to: (1) the binding of loosely-bound neutron halo nuclei; (2) the N=14--16 region in the neutron-rich isotopes of O, F, and Ne where the strong two-body interaction plays an important role; (3) the deformed intruder state region around {sup 31}Na of long standing interest; (4) the neutron-rich isotopes of sulfur and chlorine; and (5) the question of the isospin dependence (or independence) of neutron and proton pairing energies in the fp shell. Only the briefest account of this work can be given here; emphasis is placed on the most recent results. 24 refs., 3 figs.

  3. Exploration of the neutron-rich mass surface from {sup 11}Li to {sup 66}Fe

    SciTech Connect (OSTI)

    Vieira, D.J.; Wouters, J.M.; Butler, G.W. [Los Alamos National Lab., NM (United States); Seifert, H.L. [Los Alamos National Lab., NM (United States)]|[Giessen Univ. (Germany). 2. Physikalisches Inst.; Zhou, Z.Y. [Los Alamos National Lab., NM (United States)]|[Nanjing Univ., JS (China). Dept. of Physics and Astronomy; Zhou, X.G.; Tu, X.L.; Lind, V.G. [Utah State Univ., Logan, UT (United States). Dept. of Physics; Loebner, K.E.G. [Muenchen Univ. (Germany). Sektion Physik

    1991-12-01T23:59:59.000Z

    A small revolution in our ability to perform mass measurements of light-mass, neutron-rich nuclei has occurred during the last five years with the extension of the direct, total mass measurement method to fast recoiling nuclei. To date the work of two groups, one using the SPEG spectrometer at GANIL and the other using the TOFI spectrometer at LAMPF, has yielded over 85 mass measurements of which 62 had not been reported previously. Extending from the neutron-halo nucleus {sup 11}Li up to {sup 66}Fe, a region relevant to the astrophysical r-process, these measurements have provided a valuable first glimpse into the interesting nuclear structure present in many of these exotic nuclei. Herein we highlight the nuclear structure insight which as been gained from these measurements, especially that learned from a comparison to recent shell model calculations. Attention is given to: (1) the binding of loosely-bound neutron halo nuclei; (2) the N=14--16 region in the neutron-rich isotopes of O, F, and Ne where the strong two-body interaction plays an important role; (3) the deformed intruder state region around {sup 31}Na of long standing interest; (4) the neutron-rich isotopes of sulfur and chlorine; and (5) the question of the isospin dependence (or independence) of neutron and proton pairing energies in the fp shell. Only the briefest account of this work can be given here; emphasis is placed on the most recent results. 24 refs., 3 figs.

  4. Comparison of three gamma ray isotopic determination codes: FRAM, MGA, and TRIFID

    SciTech Connect (OSTI)

    Cremers, T.L.; Malcom, J.E.; Bonner, C.A.

    1994-08-01T23:59:59.000Z

    The determination of the isotopic distribution of plutonium and the americium concentration is required for the assay of nuclear material by calorimetry or neutron coincidence counting. The isotopic information is used in calorimetric assay to compute the effective specific power from the measured isotopic fractions and the known specific power of each isotope. The effective specific power is combined with the heat measurement to obtain the mass of plutonium in the assayed nuclear material. The response of neutron coincidence counters is determined by the {sup 240}Pu isotopic fraction with contributions from the other even plutonium isotopes. The effect of the {sup 240}Pu isotopic fraction and the other neutron contributing isotopes are combined as {sup 240}Pu effective. This is used to calculate the mass of nuclear material from the neutron counting data in a manner analogous to the effective specific power in calorimeter. Comparisons of the precision and accuracy of calorimetric assay and neutron coincidence counting often focus only on the precision and accuracy of the heat measurement (calorimetry) compared to the precision and accuracy of the neutron coincidence counting statistics. The major source of uncertainty for both calorimetric assay and neutron coincidence counting often lies in the determination of the plutonium isotopic distribution ad determined by gamma ray spectroscopy. Thus, the selection of the appropriate isotopic distribution code is of paramount importance to good calorimetric assay and neutron coincidence counting. Three gamma ray isotopic distribution codes, FRAM, MGA, and TRIFID have been compared at the Los Alamos Plutonium Facility under carefully controlled conditions of similar count rates, count times, and {sup 240}Pu isotopic fraction.

  5. Absolute neutrino mass measurements

    SciTech Connect (OSTI)

    Wolf, Joachim [Karlsruhe Institute of Technology (KIT), IEKP, Postfach 3640, 76021 Karlsruhe (Germany)

    2011-10-06T23:59:59.000Z

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

  6. ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.

    SciTech Connect (OSTI)

    BULLOCK,R.M.; BENDER,B.R.

    2000-12-01T23:59:59.000Z

    The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

  7. Laser isotope separation of erbium and other isotopes

    DOE Patents [OSTI]

    Haynam, Christopher A. (3035 Ferdale Ct., Pleasanton, CA 94566); Worden, Earl F. (117 Vereda del Ciervo, Diablo, CA 94528)

    1995-01-01T23:59:59.000Z

    Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of .sup.167 Er. The hyperfine structure of .sup.167 Er was used to find two three-step photoionization pathways having a common upper energy level.

  8. Laser isotope separation of erbium and other isotopes

    DOE Patents [OSTI]

    Haynam, C.A.; Worden, E.F.

    1995-08-22T23:59:59.000Z

    Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of {sup 167}Er. The hyperfine structure of {sup 167}Er was used to find two three-step photoionization pathways having a common upper energy level. 3 figs.

  9. Water isotopes and the general circulation

    E-Print Network [OSTI]

    Noone, David

    is depleted. #12;Distillation: vapor and condensate Isotopic fractionation -35 -30 -25 -20 -15 -10 -5 0 5 0 0 of idealized isotopic fractionation Expression of isotopic fractionation in nature Attributing signals" 18 = (R/Rstandard-1)x1000 R = moles of H2 18O/moles of H2 16O #12;Isotopic fractionation Isotopic

  10. between the nucleus and cytoplasm occurs through large macromolecular structures, the nuclear pores. Quantitative

    E-Print Network [OSTI]

    Forbes, Douglass

    the cytoplasm. Together these are assem- bled at points of fusion between the inner and outer nuclear membranes363 between the nucleus and cytoplasm occurs through large macromolecular structures, the nuclear pores. Quantitative scanning transmission electron microscopy has estimated the mass of a nuclear pore

  11. Accelerator mass spectrometry: from nuclear physics to dating

    SciTech Connect (OSTI)

    Kutschera, W.

    1982-01-01T23:59:59.000Z

    The discussion reviews the use of accelerators originally intended for nuclear physics to do high resolution mass spectrometry for the purpose of isotope dating and age estimation of materials. (GHT)

  12. Novel Isotope Effects and Organic Reaction Mechanisms

    E-Print Network [OSTI]

    Kelly, Kelmara K.

    2010-07-14T23:59:59.000Z

    to account for the observed isotope effects. In the dimerization of cyclopentadiene, novel "dynamic" isotope effects are observed on the 13C distribution in the product, and a method for the prediction of these isotope effects is developed here...

  13. Development of Halide and Oxy-Halides for Isotopic Separations

    SciTech Connect (OSTI)

    Leigh R. Martin; Aaron T. Johnson; Jana Pfeiffer; Martha R. Finck

    2014-10-01T23:59:59.000Z

    The goal of this project was to synthesize a volatile form of Np for introduction into mass spectrometers at INL. Volatile solids of the 5f elements are typically those of the halides (e.g. UF6), however fluorine is highly corrosive to the sensitive internal components of the mass separator, and the other volatile halides exist as several different stable isotopes in nature. However, iodide is both mono-isotopic and volatile, and as such presents an avenue for creation of a form of Np suitable for introduction into the mass separator. To accomplish this goal, the technical work in the project sought to establish a novel synthetic route for the conversion NpO2+ (dissolved in nitric acid) to NpI3 and NpI4.

  14. Isotope effect studies of the pyridoxal 5'-phosphate dependent histidine decarboxylase from Morganella morganii

    SciTech Connect (OSTI)

    Abell, L.M.; O'Leary, M.H.

    1988-08-09T23:59:59.000Z

    The pyridoxal 5'-phosphate dependent histidine decarboxylase from Morganella morganii shows a nitrogen isotope effect k/sup 14//k/sup 15/ = 0.9770 +/- 0.0021, a carbon isotope effect k/sup 12//k/sup 13/ = 1.0308 +/- 0.0006, and a carbon isotope effect for L-(..cap alpha..-/sup 2/H)histidine of 1.0333 +/- 0.0001 at pH 6.3, 37/sup 0/C. These results indicate that the overall decarboxylation rate is limited jointly by the rate of Schiff base interchange and by the rate of decarboxylation. Although the observed isotope effects are quite different from those for the analogous glutamate decarboxylase from Escherichia coli, the intrinsic isotope effects for the two enzymes are essentially the same. The difference in observed isotope effects occurs because of a roughly twofold difference in the partitioning of the pyridoxal 5'-phosphate-substrate Schiff base between decarboxylation and Schiff base interchange. The observed nitrogen isotope effect requires that the imine nitrogen in this Schiff base is protonated. Comparison of carbon isotope effects for deuteriated and undeuteriated substrates reveals that the deuterium isotope effect on the decarboxylation step is about 1.20; thus, in the transition state for the decarboxylation step, the carbon-carbon bond is about two-thirds broken.

  15. Upper limits for the existence of long-lived isotopes of roentgenium in natural gold

    SciTech Connect (OSTI)

    Dellinger, F.; Kutschera, W.; Forstner, O.; Golser, R.; Priller, A.; Steier, P.; Wallner, A.; Winkler, G. [University of Vienna, Faculty of Physics, Vienna Environmental Research Accelerator (VERA) Laboratory, Waehringer Strasse 17, A-1090 Wien (Austria)

    2011-01-15T23:59:59.000Z

    A sensitive search for isotopes of a superheavy element (SHE) in natural gold materials has been performed with accelerator mass spectrometry at the Vienna Environmental Research Accelerator, which is based on a 3-MV tandem accelerator. Because the most likely SHE in gold is roentgenium (Rg, Z = 111), the search concentrated on Rg isotopes. Two different mass regions were explored: (i) For the neutron-deficient isotopes {sup 261}Rg and {sup 265}Rg, abundance limits in gold of 3x10{sup -16} were reached (no events observed). This is in stark contrast to the findings of Marinov et al.[Int. J. Mod. Phys. E 18, 621 (2009)], who reported positive identification of these isotopes with inductively coupled plasma sector field mass spectrometry in the (1-10)x10{sup -10} abundance range. (ii) Theoretical models of SHEs predict a region of increased stability around the proton and neutron shell closures of Z = 114 and N = 184. We therefore investigated eight heavy Rg isotopes, {sup A}Rg, A = 289, 290, 291, 292, 293, 294, 295, and 296. For six isotopes no events were observed, setting limits also in the 10{sup -16} abundance range. For {sup 291}Rg and {sup 294}Rg we observed two and nine events, respectively, which results in an abundance in the 10{sup -15} range. However, pileup of a particularly strong background in these cases makes a positive identification as Rg isotopes--even after pileup correction--unlikely.

  16. Chromatographic hydrogen isotope separation

    DOE Patents [OSTI]

    Aldridge, Frederick T. (Livermore, CA)

    1981-01-01T23:59:59.000Z

    Intermetallic compounds with the CaCu.sub.5 type of crystal structure, particularly LaNiCo.sub.4 and CaNi.sub.5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation colum. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale mutli-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors.

  17. ARM - Measurement - Isotope ratio

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDC documentationBarrow,ice particleSizegovMeasurementsIsotope ratio

  18. The marine biogeochemistry of zinc isotopes

    E-Print Network [OSTI]

    John, Seth G

    2007-01-01T23:59:59.000Z

    Zinc (Zn) stable isotopes can record information about important oceanographic processes. This thesis presents data on Zn isotopes in anthropogenic materials, hydrothermal fluids and minerals, cultured marine phytoplankton, ...

  19. Stable Isotope Fractionations in Biogeochemical Reactive Transport

    E-Print Network [OSTI]

    Druhan, Jennifer Lea

    2012-01-01T23:59:59.000Z

    characteristic of stable isotope enrichment. The values of !isotope ratios of sulfur in these sulfate samples demonstrated a clear enrichmentisotope ( 34 S) (Canfield, 2001). The characteristic enrichment

  20. Strategic Isotope Production | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Strategic Isotope Production SHARE Strategic Isotope Production Typical capsules used in the transport of 252Cf source material inside heavily shielded shipping casks. ORNL's...

  1. Isotopic Trends in Production of Superheavies

    SciTech Connect (OSTI)

    Antonenko, N.V. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, D-35392 Giessen (Germany); Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Adamian, G.G.; Zubov, A.S. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, D-35392 Giessen (Germany)

    2005-11-21T23:59:59.000Z

    The isotopic trends are discussed for cold and hot fusion reactions leading to superheavies. The possibilities of production of new isotopes in incomplete fusion reactions are treated.

  2. Isotope Research 229 Th production

    E-Print Network [OSTI]

    Isotope Research ­ 229 Th production We recently completed an ARRA-funded project of this type on 229 Th production reactions [Str11]. This long-lived isotope is important as a precursor to 225 Ac of accelerator production of 229 Th via the 230 Th(p,2n)229 Pa reaction. The 229 Pa decays primarily by electron

  3. Method of separating boron isotopes

    DOE Patents [OSTI]

    Jensen, Reed J. (Los Alamos, NM); Thorne, James M. (Provo, UT); Cluff, Coran L. (Provo, UT); Hayes, John K. (Salt Lake City, UT)

    1984-01-01T23:59:59.000Z

    A method of boron isotope enrichment involving the isotope preferential photolysis of (2-chloroethenyl)dichloroborane as the feed material. The photolysis can readily be achieved with CO.sub.2 laser radiation and using fluences significantly below those required to dissociate BCl.sub.3.

  4. Method of separating boron isotopes

    DOE Patents [OSTI]

    Jensen, R.J.; Thorne, J.M.; Cluff, C.L.

    1981-01-23T23:59:59.000Z

    A method of boron isotope enrichment involving the isotope preferential photolysis of (2-chloroethenyl)-dichloroborane as the feed material. The photolysis can readily by achieved with CO/sub 2/ laser radiation and using fluences significantly below those required to dissociate BCl/sub 3/.

  5. Formation of Light Isotopes by Protons and Deuterons of 3.65 GeV/nucleon on Separated Tin Isotopes

    E-Print Network [OSTI]

    A. R. Balabekyan; A. S. Danagulyan; J. R. Drnoyan; G. H. Hovhannisyan; J. Adam; V. G. Kalinnikov; M. I. Krivopustov; V. S. Pronskikh; V. I. Stegailov; A. A. Solnyshkin; P. Chaloun; V. M. Tsoupko-Sitnikov; S. G. Mashnik; K. K. Gudima

    2005-06-22T23:59:59.000Z

    We measure cross sections for residual nuclide formation in the mass range 6 tin isotopes (112-Sn, 118-Sn, 120-Sn, 124-Sn). The experimental data are compared with calculations by the codes FLUKA, LAHET, CEM03, and LAQGSM03. Scaling behavior is observed for the whole mass region of residual nuclei, showing a possible multifragmentation mechanism for the formation of light products (6 < A < 31). Our analysis of the isoscaling dependence also shows a possible contribution of multifragmentation to the production of heavier nuclides, in the mass region 39 < A < 81.

  6. On the origin of the lightest Molybdenum isotopes

    E-Print Network [OSTI]

    Jacob Lund Fisker; Robert D. Hoffman; Jason Pruet

    2009-01-15T23:59:59.000Z

    We discuss implications of recent precision measurements for the Rh93 proton separation energy for the production of the lightest molybdenum isotopes in proton-rich type II supernova ejecta. It has recently been shown that a novel neutrino-induced process makes these ejecta a promising site for the production of the light molybdenum isotopes and other "p-nuclei" with atomic mass near 100. The origin of these isotopes has long been uncertain. A distinguishing feature of nucleosynthesis in neutrino-irradiated outflows is that the relative production of Mo92 and Mo94 is set by a competition governed by the proton separation energy of Rh93. We use detailed nuclear network calculations and the recent experimental results for this proton separation energy to place constraints on the outflow characteristics that produce the lightest molybdenum isotopes in their solar proportions. It is found that for the conditions calculated in recent two-dimensional supernova simulations, and also for a large range of outflow characteristics around these conditions, the solar ratio of Mo92 to Mo94 cannot be achieved. This suggests that either proton-rich winds from type II supernova do not exclusively produce both isotopes, or that these winds are qualitatively different than calculated in today's supernova models.

  7. Isotopically Enriched Films and Nanostructures by Ultrafast Pulsed Laser Deposition

    SciTech Connect (OSTI)

    Peter Pronko

    2004-12-13T23:59:59.000Z

    This project involved a systematic study to apply newly discovered isotopic enrichment effects in laser ablation plumes to the fabrication of isotopically engineered thin films, superlattices, and nanostructures. The approach to this program involved using ultrafast lasers as a method for generating ablated plasmas that have preferentially structured isotopic content in the body of the ablation plasma plumes. In examining these results we have attempted to interpret the observations in terms of a plasma centrifuge process that is driven by the internal electro-magnetic fields of the plasma itself. The research plan involved studying the following phenomena in regard to the ablation plume and the isotopic mass distribution within it: (1) Test basic equations of steady state centrifugal motion in the ablation plasma. (2) Investigate angular distribution of ions in the ablation plasmas. (3) Examine interactions of plasma ions with self-generated magnetic fields. (3) Investigate ion to neutral ratios in the ablation plasmas. (5) Test concepts of plasma pumping. (6) Fabricate isotopically enriched nanostructures.

  8. The use of carbon stable isotope ratios in drugs characterization

    SciTech Connect (OSTI)

    Magdas, D. A., E-mail: gabriela.cristea@itim-cj.ro; Cristea, G., E-mail: gabriela.cristea@itim-cj.ro; Bot, A., E-mail: gabriela.cristea@itim-cj.ro; Mirel, V., E-mail: gabriela.cristea@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania)

    2013-11-13T23:59:59.000Z

    Isotopic Ratio Mass Spectrometry (IRMS) is an effective toll to be used for drug product authentication. The isotopic composition could be used to assist in the differentiation between batches of drugs and assist in the identification of counterfeit materials on the market. Only two factors affect the isotopic ratios in pharmaceutical components: the isotopic composition of the raw materials and the synthetic processes performed upon them. Counterfeiting of pharmaceutical drugs threatens consumer confidence in drug products companies' economical well-being. In this preliminary study, the analyzed samples consist in two types of commercially available analgesics, which were purchases from Romanian pharmacies. Differences in ?{sup 13}C between batches from ?29.7 to ?31.6% were observed, demonstrating that this method can be used to differentiate among individual drug batches and subsequently identify counterfeits on the market. On the other hand, carbon isotopic ratios differences among producers were recorded, the variations being between ?31.3 to ?34.9% for the same type of analgesic, but from different manufactures.

  9. System size effects in the N/Z dependence of balance energy for isotopic series

    E-Print Network [OSTI]

    Sakshi Gautam; Aman Deep Sood

    2011-07-25T23:59:59.000Z

    We study the system size effects in the N/Z dependence of balance energy for the isotopic series. We find drastic effect of symmetry energy on the N/Z dependence of E$_{bal}$ throughout the mass range. We also find that the N/Z dependence of E$_{bal}$ for isotopic series of lighter system is slightly more sensitive to symmetry energy as compared to that of heavier systems. We also study the mass dependence of E$_{bal}$ for the N/Z range from 1.0-2.0. We find that the mass dependence of E$_{bal}$ varies with the N/Z ratio.

  10. Data report: High-resolution stable isotope stratigraphy of the late Middle Eocene at Site 1051, Blake Nose

    E-Print Network [OSTI]

    Wade, Bridget S.; Norris, Richard D.; Kroom, Dick

    2000-01-01T23:59:59.000Z

    samples were analyzed isotopically using a VG Isogas Prism III mass spectrometer at the University of Edinburgh, Scotland. Normal corrections were employed, and results of stable iso- tope measurements are expressed in parts per thousand relative...

  11. Advancement of isotope separation for the production of reference standards

    SciTech Connect (OSTI)

    Jared Horkley; Christopher McGrath; Andrew Edwards; Gaven Knighton; Kevin Carney; Jacob Davies; James Sommers; Jeffrey Giglio

    2012-03-01T23:59:59.000Z

    Idaho National Laboratory (INL) operates a mass separator that is currently producing high purity isotopes for use as internal standards for high precision isotope dilution mass spectrometry (IDMS). In 2008, INL began the revival of the vintage 1970’s era instrument. Advancements thus far include the successful upgrading and development of system components such as the vacuum system, power supplies, ion-producing components, and beam detection equipment. Progress has been made in the separation and collection of isotopic species including those of Ar, Kr, Xe, Sr, and Ba. Particular focuses on ion source improvements and developments have proven successful with demonstrated output beam currents of over 10 micro-amps 138Ba and 350nA 134Ba from a natural abundance source charge (approximately 2.4 percent 134Ba). In order to increase production and collection of relatively high quantities (mg levels) of pure isotopes, several advancements have been made in ion source designs, source material introduction, and beam detection and collection. These advancements and future developments will be presented.

  12. Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes

    SciTech Connect (OSTI)

    Draayer, Jerry P [Louisiana State University

    2014-09-28T23:59:59.000Z

    We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

  13. NEUTRON-POOR NICKEL ISOTOPE ANOMALIES IN METEORITES

    SciTech Connect (OSTI)

    Steele, Robert C. J.; Coath, Christopher D.; Regelous, Marcel; Elliott, Tim [Bristol Isotope Group, School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ (United Kingdom); Russell, Sara, E-mail: r.steele@uclmail.net [Meteoritics and Cosmic mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom)

    2012-10-10T23:59:59.000Z

    We present new, mass-independent, Ni isotope data for a range of bulk chondritic meteorites. The data are reported as {epsilon}{sup 60}Ni{sub 58/61}, {epsilon}{sup 62}Ni{sub 58/61}, and {epsilon}{sup 64}Ni{sub 58/61}, or the parts per ten thousand deviations from a terrestrial reference, the NIST SRM 986 standard, of the {sup 58}Ni/{sup 61}Ni internally normalized {sup 60}Ni/{sup 61}Ni, {sup 62}Ni/{sup 61}Ni, and {sup 64}Ni/{sup 61}Ni ratios. The chondrites show a range of 0.15, 0.29, and 0.84 in {epsilon}{sup 60}Ni{sub 58/61}, {epsilon}{sup 62}Ni{sub 58/61}, and {epsilon}{sup 64}Ni{sub 58/61} relative to a typical sample precision of 0.03, 0.05, and 0.08 (2 s.e.), respectively. The carbonaceous chondrites show the largest positive anomalies, enstatite chondrites have approximately terrestrial ratios, though only EH match Earth's composition within uncertainty, and ordinary chondrites show negative anomalies. The meteorite data show a strong positive correlation between {epsilon}{sup 62}Ni{sub 58/61} and {epsilon}{sup 64}Ni{sub 58/61}, an extrapolation of which is within the error of the average of previous measurements of calcium-, aluminium-rich inclusions. Moreover, the slope of this bulk meteorite array is 3.003 {+-} 0.166 which is within the error of that expected for an anomaly solely on {sup 58}Ni. We also determined to high precision ({approx}10 ppm per AMU) the mass-dependent fractionation of two meteorite samples which span the range of {epsilon}{sup 62}Ni{sub 58/61} and {epsilon}{sup 64}Ni{sub 58/61}. These analyses show that 'absolute' ratios of {sup 58}Ni/{sup 61}Ni vary between these two samples whereas those of {sup 62}Ni/{sup 61}Ni and {sup 64}Ni/{sup 61}Ni do not. Thus, Ni isotopic differences seem most likely explained by variability in the neutron-poor {sup 58}Ni, and not correlated anomalies in the neutron-rich isotopes, {sup 62}Ni and {sup 64}Ni. This contrasts with previous inferences from mass-independent measurements of Ni and other transition elements which invoked variable contributions of a neutron-rich component. We have examined different nucleosynthetic environments to determine the possible source of the anomalous material responsible for the isotopic variations observed in Ni and other transition elements within bulk samples. We find that the Ni isotopic variability of the solar system cannot be explained by mixing with a component of bulk stellar ejecta from either SN II, Wolf-Rayet or, an asymptotic giant branch source and is unlikely to result from bulk mixing of material from an SN Ia. However, variable admixture of material from the Si/S zone of an SN II can create all the characteristics of Ni isotope variations in solar system materials. Moreover, these characteristics can also be provided by an SN II with a range of masses from 15 to 40 M{sub Sun }, showing that input from SN II is a robust source for Ni isotope variations in the solar system. Correlations of Ni isotope anomalies with O, Cr, and Ti isotope ratios and Pb/Yb in bulk meteorites suggest that the heterogeneous distribution of isotopic anomalies in the early solar system likely resulted from nebular sorting of chemically or physically different materials bearing different amounts of isotopes synthesized proximally to the collapse of the protosolar nebula.

  14. Key changes in proteins occur in cyanobacteria | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    proteins occur in cyanobacteria Identification of redox-sensitive enzymes can enrich biofuel production research Overview of the chemical biology technique used by PNNL...

  15. Determining Planes Along Which Earthquakes Occur- Method of Applicatio...

    Open Energy Info (EERE)

    Along Which Earthquakes Occur- Method of Application to Earthquakes Accompanying Hydraulic Fracturing Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  16. Apparatus and process for separating hydrogen isotopes

    DOE Patents [OSTI]

    Heung, Leung K; Sessions, Henry T; Xiao, Xin

    2013-06-25T23:59:59.000Z

    The apparatus and process for separating hydrogen isotopes is provided using dual columns, each column having an opposite hydrogen isotopic effect such that when a hydrogen isotope mixture feedstock is cycled between the two respective columns, two different hydrogen isotopes are separated from the feedstock.

  17. Method for laser induced isotope enrichment

    DOE Patents [OSTI]

    Pronko, Peter P.; Vanrompay, Paul A.; Zhang, Zhiyu

    2004-09-07T23:59:59.000Z

    Methods for separating isotopes or chemical species of an element and causing enrichment of a desired isotope or chemical species of an element utilizing laser ablation plasmas to modify or fabricate a material containing such isotopes or chemical species are provided. This invention may be used for a wide variety of materials which contain elements having different isotopes or chemical species.

  18. Compelling Research Opportunities using Isotopes

    SciTech Connect (OSTI)

    None

    2009-04-23T23:59:59.000Z

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1) medicine, pharmaceuticals, and biology, (2) physical sciences and engineering, and (3) national security and other applications. In each area, compelling research opportunities were considered and the subcommittee as a whole determined the final priorities for research opportunities as the foundations for the recommendations. While it was challenging to prioritize across disciplines, our order of recommendations reflect the compelling research prioritization along with consideration of time urgency for action as well as various geopolitical market issues. Common observations to all areas of research include the needs for domestic availability of crucial stable and radioactive isotopes and the education of the skilled workforce that will develop new advances using isotopes in the future. The six recommendations of NSACI reflect these concerns and the compelling research opportunities for potential new discoveries. The science case for each of the recommendations is elaborated in the respective chapters.

  19. Electrochemical Isotope Effect and Lithium Isotope Separation Jay R. Black,

    E-Print Network [OSTI]

    Mcdonough, William F.

    results showing a large lithium isotope separation due to electrodeposition. The fractionation is tunable lithium were plated from solutions of 1 M LiClO4 in propylene carbonate (PC) on planar nickel electrodes

  20. annually occurring aerosol: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in two modes: (1) a continuous mass spectrum mode without size information; and (2) a size distribution measurement mode for selected mz settings of the quadrupole. Single...

  1. Original article Hydraulic conductance of two co-occuring neotropical

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Original article Hydraulic conductance of two co-occuring neotropical understory shrubs December 1999) Abstract ­ Whole plant hydraulic conductance was measured for two co-occuring neotropical hydraulic con- ductance and leaf specific conducance in the drought-avoiding species, P. trigonum, than

  2. Elastic scattering of Beryllium isotopes near the Coulomb barrier

    SciTech Connect (OSTI)

    Di Pietro, A.; Figuera, P. [INFN-Laboratori Nazionali del Sud, Catania (Italy); Amorini, F.; Fisichella, M.; Lattuada, M.; Musumarra, A.; Pellegriti, M. G.; Randisi, G.; Rizzo, F.; Santonocito, D.; Scalia, G.; Scuderi, V.; Strano, E.; Torresi, D. [Dipartimento di Fisica ed Astronomia Universita di Catania, Catania (Italy); INFN-Laboratori Nazionali del Sud, Catania (Italy); Papa, M. [INFN-Sezione di Catania, Catania (Italy); Acosta, L.; Martel, I.; Perez-Bernal, F. [Departamento de Fisica Aplicada Universidad de Huelva, Huelva (Spain); Borge, M. J. G.; Tengblad, O. [Instituto de Estructura de la Materia CSIC, Madrid (Spain)

    2011-10-28T23:59:59.000Z

    In this contribution, results of experiments performed with the three Beryllium isotopes {sup 9,10,11}Be on a medium mass {sup 64}Zn target, at a center of mass energy of {approx_equal}1.4 the Coulomb barrier, will be discussed. Elastic scattering angular distributions have been measured for the {sup 9,10}Be reactions. In the {sup 11}Be case the quasielastic scattering angular distribution was obtained. In the halo nucleus case, the angular distribution exhibit a non-Fresnel-type pattern with a strong damping of the Coulomb-nuclear interference peak. Moreover, it is found that the total reaction cross-section for the halo nucleus induced collision is more than double the ones extracted in the collisions induced by the non-halo Beryllium isotopes. A large contribution to the total-reaction cross-section in the {sup 11}Be case could be attributed to transfer and/or break-up events.

  3. Metallic beam development for the Facility for Rare Isotope Beam

    SciTech Connect (OSTI)

    Machicoane, Guillaume, E-mail: machicoa@nscl.msu.edu; Cole, Dallas; Leitner, Daniela; Neben, Derek; Tobos, Larry [Facility for Rare Isotope Beam, Michigan State University, East Lansing, Michigan 48824 (United States)] [Facility for Rare Isotope Beam, Michigan State University, East Lansing, Michigan 48824 (United States)

    2014-02-15T23:59:59.000Z

    The Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) will accelerate a primary ion beam to energies beyond 200 MeV/u using a superconducting RF linac and will reach a maximum beam power of 400 kW on the fragmentation target. The beam intensity needed from the ECR ion source is expected to be between 0.4 and 0.5 emA for most medium mass to heavy mass elements. Adding to the challenge of reaching the required intensity, an expanded list of primary beams of interest has been established based on the production rate and the number of isotope beams that could be produced with FRIB. We report here on the development done for some of the beam in the list including mercury (natural), molybdenum ({sup 98}Mo), and selenium ({sup 82}Ser)

  4. Novel hybrid isotope separation scheme and apparatus

    DOE Patents [OSTI]

    Maya, Jakob (Brookline, MA)

    1991-01-01T23:59:59.000Z

    A method of yielding selectively a desired enrichment in a specific isotope including the steps of inputting into a spinning chamber a gas from which the specific isotope is to be isolated, radiating the gas with frequencies characteristic of the absorption of a particular isotope of the atomic or molecular gas, thereby inducing a photoionization reaction of the desired isotope, and collecting the specific isotope ion by suitable ion collection means.

  5. Novel hybrid isotope separation scheme and apparatus

    DOE Patents [OSTI]

    Maya, J.

    1991-06-18T23:59:59.000Z

    A method is described for yielding selectively a desired enrichment in a specific isotope including the steps of inputting into a spinning chamber a gas from which the specific isotope is to be isolated, radiating the gas with frequencies characteristic of the absorption of a particular isotope of the atomic or molecular gas, thereby inducing a photoionization reaction of the desired isotope, and collecting the specific isotope ion by suitable ion collection means. 3 figures.

  6. Chromium isotopes as indicators of hexavalent chromium reduction

    SciTech Connect (OSTI)

    Johnson, Thomas M.

    2012-03-20T23:59:59.000Z

    This is the final report for a university research project which advanced development of a new technology for identifying chemical reduction of hexavalent chromium contamination in groundwater systems. Reduction renders mobile and toxic hexavalent chromium immobile and less toxic. The new method uses stable isotope ratio measurements, which are made using multicollector ICP-mass spectrometry. The main objectives of this project were completed during the project period and two peer-reviewed articles were published to disseminate the information gained.

  7. Selective photoionisation of lutetium isotopes

    SciTech Connect (OSTI)

    D'yachkov, Aleksei B; Kovalevich, S K; Labozin, Valerii P; Mironov, Sergei M; Panchenko, Vladislav Ya; Firsov, Valerii A; Tsvetkov, G O; Shatalova, G G [National Research Centre 'Kurchatov Institute', Moscow (Russian Federation)

    2012-10-31T23:59:59.000Z

    A three-stage laser photoionisation scheme intended for enriching the {sup 176}Lu isotope from natural lutetium was considered. An investigation was made of the hyperfine structure of the second excited state 5d6s7s {yields} {sup 4}D{sub 3/2} with an energy of 37194 cm{sup -1} and the autoionisation state with an energy of 53375 cm{sup -1} of the {sup 176}Lu and {sup 175}Lu isotopes. The total electron momentum of the autoionisation level and the constant A of hyperfine magnetic interaction were determined. Due to a small value of the isotopic shift between {sup 176}Lu and {sup 175}Lu, appreciable selectivity of their separation may be achieved with individual hyperfine structure components. The first tentative enrichment of the 176Lu isotope was performed to a concentration of 60 % - 70 %. (laser applications and other topics in quantum electronics)

  8. ZIRCONIUM—HAFNIUM ISOTOPE EVIDENCE FROM METEORITES FOR THE DECOUPLED SYNTHESIS OF LIGHT AND HEAVY NEUTRON-RICH NUCLEI

    SciTech Connect (OSTI)

    Akram, W.; Schönbächler, M. [School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Sprung, P. [Institut für Planetologie, Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Vogel, N. [Institute for Geochemistry and Petrology, ETH, Clausiusstrasse 25, 8092 Zürich (Switzerland)

    2013-11-10T23:59:59.000Z

    Recent work based on analyses of meteorite and terrestrial whole-rock samples showed that the r- and s- process isotopes of Hf were homogeneously distributed throughout the inner solar system. We report new Hf isotope data for Calcium-Aluminum-rich inclusions (CAIs) of the CV3 carbonaceous chondrite Allende, and novel high-precision Zr isotope data for these CAIs and three carbonaceous chondrites (CM, CO, CK). Our Zr data reveal enrichments in the neutron-rich isotope {sup 96}Zr (?1? in {sup 96}Zr/{sup 90}Zr) for bulk chondrites and CAIs (?2?). Potential isotope effects due to incomplete sample dissolution, galactic and cosmic ray spallation, and the nuclear field shift are assessed and excluded, leading to the conclusion that the {sup 96}Zr isotope variations are of nucleosynthetic origin. The {sup 96}Zr enrichments are coupled with {sup 50}Ti excesses suggesting that both nuclides were produced in the same astrophysical environment. The same CAIs also exhibit deficits in r-process Hf isotopes, which provides strong evidence for a decoupling between the nucleosynthetic processes that produce the light (A ? 130) and heavy (A > 130) neutron-rich isotopes. We propose that the light neutron-capture isotopes largely formed in Type II supernovae (SNeII) with higher mass progenitors than the supernovae that produced the heavy r-process isotopes. In the context of our model, the light isotopes (e.g. {sup 96}Zr) are predominantly synthesized via charged-particle reactions in a high entropy wind environment, in which Hf isotopes are not produced. Collectively, our data indicates that CAIs sampled an excess of materials produced in a normal mass (12-25 M{sub ?}) SNII.

  9. Isotope production facility produces cancer-fighting actinium

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cancer therapy gets a boost from new isotope Isotope production facility produces cancer-fighting actinium A new medical isotope project shows promise for rapidly producing major...

  10. Higher-Order Mass Defect Analysis for Mass Spectra of Complex Organic Mixtures

    SciTech Connect (OSTI)

    Roach, Patrick J.; Laskin, Julia; Laskin, Alexander

    2011-06-15T23:59:59.000Z

    Higher-order mass defect analysis is introduced as a unique formula assignment and visualization method for the analysis of complex mass spectra. This approach is an extension of the concepts of Kendrick mass transformation widely used for identification of homologous compounds differing only by a number of base units (e.g., CH2, H2, O, CH2O, etc.) in complex mixtures. We present an iterative renormalization routine for defining higher order homologous series and multidimensional clustering of mass spectral features. This approach greatly simplifies visualization of complex mass spectra and increases the number of chemical formulae that can be confidently assigned for given mass accuracy. The potential for using higher-order mass defects for data reduction and visualization is shown. Higher-order mass defect analysis is described and demonstrated through third-order analysis of a de-isotoped high-resolution mass spectrum of crude oil containing nearly 13,000 peaks.

  11. Cryomodule Design for the Rare Isotope Accelerator

    SciTech Connect (OSTI)

    Grimm, Terry; Hartung, Walter; Johnson, M.; York, Richard; Kneisel, Peter; Turlington, Larry

    2003-05-01T23:59:59.000Z

    The Rare Isotope Accelerator (RIA) driver linac will produce >400 MeV/u proton through uranium beams using many types of superconducting accelerating cavities such as quarter wave, spoke, and elliptical cavities. A cryomodule design that can accommodate all of the superconducting cavity and magnet types is presented. Alignment of the cold mass uses a titanium rail system, which minimizes cryomodule size, and decreases both the tunnel cross-section and length. The titanium rail is supported from the top vacuum plate by an adjustable trilink, which is similar to existing Michigan State University magnet technology. A prototype cryomodule is under construction for testing 805 MHz, v/c=0.47, sixcell niobium cavities in realistic operating conditions. Details of the design and progress to date are presented.

  12. Consistency test of neutrinoless double beta decay with one isotope

    E-Print Network [OSTI]

    Michael Duerr; Manfred Lindner; Kai Zuber

    2011-11-17T23:59:59.000Z

    We discuss a consistency test which makes it possible to discriminate unknown nuclear background lines from neutrinoless double beta decay with only one isotope. By considering both the transition to the ground state and to the first excited $0^+$ state, a sufficiently large detector can reveal if neutrinoless double beta decay or some other nuclear physics process is at work. Such a detector could therefore simultaneously provide a consistency test for a certain range of Majorana masses and be sensitive to lower values of the effective Majorana mass.

  13. Consistency test of neutrinoless double beta decay with one isotope

    SciTech Connect (OSTI)

    Duerr, Michael; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Postfach 10 39 80, 69029 Heidelberg (Germany); Zuber, Kai [Technical University Dresden, Institut fuer Kern- und Teilchenphysik, 01069 Dresden (Germany)

    2011-11-01T23:59:59.000Z

    We discuss a consistency test which makes it possible to discriminate unknown nuclear background lines from neutrinoless double beta decay with only one isotope. By considering both the transition to the ground state and to the first excited 0{sup +} state, a sufficiently large detector can reveal if neutrinoless double beta decay or some other nuclear physics process is at work. Such a detector could therefore simultaneously provide a consistency test for a certain range of Majorana masses and be sensitive to lower values of the effective Majorana mass .

  14. Europium, Samarium, and Neodymium Isotopic Fractions in Metal-Poor Stars

    E-Print Network [OSTI]

    Ian U. Roederer; James E. Lawler; Christopher Sneden; John J. Cowan; Jennifer S. Sobeck; Catherine A. Pilachowski

    2007-12-16T23:59:59.000Z

    We have derived isotopic fractions of europium, samarium, and neodymium in two metal-poor giants with differing neutron-capture nucleosynthetic histories. These isotopic fractions were measured from new high resolution (R ~ 120,000), high signal-to-noise (S/N ~ 160-1000) spectra obtained with the 2dCoude spectrograph of McDonald Observatory's 2.7m Smith telescope. Synthetic spectra were generated using recent high-precision laboratory measurements of hyperfine and isotopic subcomponents of several transitions of these elements and matched quantitatively to the observed spectra. We interpret our isotopic fractions by the nucleosynthesis predictions of the stellar model, which reproduces s-process nucleosynthesis from the physical conditions expected in low-mass, thermally-pulsing stars on the AGB, and the classical method, which approximates s-process nucleosynthesis by a steady neutron flux impinging upon Fe-peak seed nuclei. Our Eu isotopic fraction in HD 175305 is consistent with an r-process origin by the classical method and is consistent with either an r- or an s-process origin by the stellar model. Our Sm isotopic fraction in HD 175305 suggests a predominantly r-process origin, and our Sm isotopic fraction in HD 196944 is consistent with an s-process origin. The Nd isotopic fractions, while consistent with either r-process or s-process origins, have very little ability to distinguish between any physical values for the isotopic fraction in either star. This study for the first time extends the n-capture origin of multiple rare earths in metal-poor stars from elemental abundances to the isotopic level, strengthening the r-process interpretation for HD 175305 and the s-process interpretation for HD196944.

  15. Diffusion in silicon isotope heterostructures

    SciTech Connect (OSTI)

    Silvestri, Hughes Howland

    2004-05-14T23:59:59.000Z

    The simultaneous diffusion of Si and the dopants B, P, and As has been studied by the use of a multilayer structure of isotopically enriched Si. This structure, consisting of 5 pairs of 120 nm thick natural Si and {sup 28}Si enriched layers, enables the observation of {sup 30}Si self-diffusion from the natural layers into the {sup 28}Si enriched layers, as well as dopant diffusion from an implanted source in an amorphous Si cap layer, via Secondary Ion Mass Spectrometry (SIMS). The dopant diffusion created regions of the multilayer structure that were extrinsic at the diffusion temperatures. In these regions, the Fermi level shift due to the extrinsic condition altered the concentration and charge state of the native defects involved in the diffusion process, which affected the dopant and self-diffusion. The simultaneously recorded diffusion profiles enabled the modeling of the coupled dopant and self-diffusion. From the modeling of the simultaneous diffusion, the dopant diffusion mechanisms, the native defect charge states, and the self- and dopant diffusion coefficients can be determined. This information is necessary to enhance the physical modeling of dopant diffusion in Si. It is of particular interest to the modeling of future electronic Si devices, where the nanometer-scale features have created the need for precise physical models of atomic diffusion in Si. The modeling of the experimental profiles of simultaneous diffusion of B and Si under p-type extrinsic conditions revealed that both species are mediated by neutral and singly, positively charged Si self-interstitials. The diffusion of As and Si under extrinsic n-type conditions yielded a model consisting of the interstitialcy and vacancy mechanisms of diffusion via singly negatively charged self-interstitials and neutral vacancies. The simultaneous diffusion of P and Si has been modeled on the basis of neutral and singly negatively charged self-interstitials and neutral and singly positively charged P species. Additionally, the temperature dependence of the diffusion coefficient of Si in Ge was measured over the temperature range of 550 C to 900 C using a buried Si layer in an epitaxially grown Ge layer.

  16. 99.996 %{sup 12}C films isotopically enriched and deposited in situ

    SciTech Connect (OSTI)

    Dwyer, K. J. [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States) [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States); National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States); Pomeroy, J. M.; Simons, D. S. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States)] [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423 (United States)

    2013-06-24T23:59:59.000Z

    Ionizing natural abundance carbon dioxide gas, we extract and mass select the ions, depositing thin films isotopically enriched to 99.9961(4) %{sup 12}C as measured by secondary ion mass spectrometry (SIMS). In solid state quantum information, coherence times of nitrogen-vacancy (NV) centers in {sup 12}C enriched diamond exceeding milliseconds demonstrate the viability of NV centers as qubits, motivating improved isotopic enrichment. NV centers in diamond are particularly attractive qubit candidates due to the optical accessibility of the spin states. We present SIMS analysis and cross-sectional scanning electron microscopy of {sup 12}C enriched thin film samples grown with this method.

  17. Nickel isotopes in stellar matter

    E-Print Network [OSTI]

    Jameel-Un Nabi

    2014-08-19T23:59:59.000Z

    Isotopes of nickel play a key role during the silicon burning phase up to the presupernova phase of massive stars. Electron capture rates on these nickel isotopes are also important during the phase of core contraction. I present here the microscopic calculation of ground and excited states Gamow-Teller (GT) strength distributions for key nickel isotopes. The calculation is performed within the frame-work of pn-QRPA model. A judicious choice of model parameters, specially of the Gamow-Teller strength parameters and the deformation parameter, resulted in a much improved calculation of GT strength functions. The excited state GT distributions are much different from the corresponding ground-state distributions resulting in a failure of the Brink's hypothesis. The electron capture and positron decay rates on nickel isotopes are also calculated within the framework of pn-QRPA model relevant to the presupernova evolution of massive stars. The electron capture rates on odd-A isotopes of nickel are shown to have dominant contributions from parent excited states during as early as silicon burning phases. Comparison is being made with the large scale shell model calculation. During the silicon burning phases of massive stars the electron capture rates on $^{57,59}$Ni are around an order of magnitude bigger than shell model rates and can bear consequences for core-collapse simulators.

  18. Chromium Isotope Fractionation During Reduction of Cr(VI) Under Saturated Flow Conditions

    SciTech Connect (OSTI)

    Jamieson-Hanes, Julia H.; Gibson, Blair D.; Lindsay, Matthew B.J.; Kim, Yeongkyoo; Ptacek, Carol J.; Blowes, David W. (Waterloo); (Kyungpook National University)

    2012-10-25T23:59:59.000Z

    Chromium isotopes are potentially useful indicators of Cr(VI) reduction reactions in groundwater flow systems; however, the influence of transport on Cr isotope fractionation has not been fully examined. Laboratory batch and column experiments were conducted to evaluate isotopic fractionation of Cr during Cr(VI) reduction under both static and controlled flow conditions. Organic carbon was used to reduce Cr(VI) in simulated groundwater containing 20 mg L{sup -1} Cr(VI) in both batch and column experiments. Isotope measurements were performed on dissolved Cr on samples from the batch experiments, and on effluent and profile samples from the column experiment. Analysis of the residual solid-phase materials by scanning electron microscopy (SEM) and by X-ray absorption near edge structure (XANES) spectroscopy confirmed association of Cr(III) with organic carbon in the column solids. Decreases in dissolved Cr(VI) concentrations were coupled with increases in {delta}{sup 53}Cr, indicating that Cr isotope enrichment occurred during reduction of Cr(VI). The {delta}{sup 53}Cr data from the column experiment was fit by linear regression yielding a fractionation factor ({alpha}) of 0.9979, whereas the batch experiments exhibited Rayleigh-type isotope fractionation ({alpha} = 0.9965). The linear characteristic of the column {delta}{sup 53}Cr data may reflect the contribution of transport on Cr isotope fractionation.

  19. The production of ultra-high purity single isotopes or tailored isotope mixtures by ICP-MS

    SciTech Connect (OSTI)

    Liezers, Martin; Farmer, Orville T.; Dion, Michael P.; Thomas, Linda MP; Eiden, Gregory C.

    2015-01-01T23:59:59.000Z

    We report the development and testing of a simple collector arrangement for a commercial quadrupole ICP-MS that for the first time has been used to produce small quantities of highly enriched (>99.99%) single isotopes, with deposition rates >10 ng/hour. The collector assembly replaces the standard instrument detector allowing for implantation with simultaneous monitoring of the incident ion current. Even under zero bias implant conditions, low energy (<10 eV), ion collection efficiency was observed to be very high ~99%. 151Eu ion currents of 0.1-0.5 nA were collected on a simple, planar foil without resorting to any type of cup configuration. Recovery of the enriched isotope from such foils is much simpler than from a more complex cup configuration. High rejection of adjacent mass isotopes was demonstrated by selectively implanting 167Er without any discernible co-implantation of 166Er and 168Er. The important analytical possibilities of the new approach to isotope ratio measurement, tracer purification and radiation measurements are discussed.

  20. Fluctuations in Species-Level Protein Expression Occur during Element and Nutrient Cycling in the Subsurface

    SciTech Connect (OSTI)

    Wilkins, Michael J.; Wrighton, Kelly C.; Nicora, Carrie D.; Williams, Kenneth H.; McCue, Lee Ann; Handley, Kim M.; Miller, C. S.; Giloteaux, L.; Montgomery, A. P.; Lovley, Derek R.; Banfield, Jillian F.; Long, Philip E.; Lipton, Mary S.

    2013-03-05T23:59:59.000Z

    While microbial activities in environmental systems play a key role in the utilization and cycling of essential elements and compounds, microbial activity and growth frequently fluctuates in response to environmental stimuli and perturbations. To investigate these fluctuations within a saturated aquifer system, we monitored a carbon-stimulated in situ Geobacter population while iron reduction was occurring, using 16S rRNA abundances and high-resolution tandem mass spectrometry proteome measurements. Following carbon amendment, 16S rRNA analysis of temporally separated samples revealed the rapid enrichment of Geobacter-like environmental strains with strong similarity to G. bemidjiensis. Tandem mass spectrometry proteomics measurements suggest high carbon flux through Geobacter respiratory pathways, and the synthesis of anapleurotic four carbon compounds from acetyl-CoA via pyruvate ferredoxin oxidoreductase activity. Across a 40-day period where Fe(III) reduction was occurring, fluctuations in protein expression reflected changes in anabolic versus catabolic reactions, with increased levels of biosynthesis occurring soon after acetate arrival in the aquifer. In addition, localized shifts in nutrient limitation were inferred based on expression of nitrogenase enzymes and phosphate uptake proteins. These temporal data offer the first example of differing microbial protein expression associated with changing geochemical conditions in a subsurface environment.

  1. Mechanistic studies using kinetic isotope effects

    E-Print Network [OSTI]

    Schulmeier, Brian E.

    1999-01-01T23:59:59.000Z

    Understanding reaction mechanisms is an important aspect of chemistry. A now convenient way to study reaction mechanisms is kinetic isotope effects at natural abundance. This technique circumvents the cumbersome methods of traditional isotope effect...

  2. Online Catalog of Isotope Products from DOE's National Isotope Development Center

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The National Isotope Development Center (NIDC) interfaces with the User Community and manages the coordination of isotope production across the facilities and business operations involved in the production, sale, and distribution of isotopes. A virtual center, the NIDC is funded by the Isotope Development and Production for Research and Applications (IDPRA) subprogram of the Office of Nuclear Physics in the U.S. Department of Energy Office of Science. The Isotope subprogram supports the production, and the development of production techniques of radioactive and stable isotopes that are in short supply for research and applications. Isotopes are high-priority commodities of strategic importance for the Nation and are essential for energy, medical, and national security applications and for basic research; a goal of the program is to make critical isotopes more readily available to meet domestic U.S. needs. This subprogram is steward of the Isotope Production Facility (IPF) at Los Alamos National Laboratory (LANL), the Brookhaven Linear Isotope Producer (BLIP) facility at BNL, and hot cell facilities for processing isotopes at ORNL, BNL and LANL. The subprogram also coordinates and supports isotope production at a suite of university, national laboratory, and commercial accelerator and reactor facilities throughout the Nation to promote a reliable supply of domestic isotopes. The National Isotope Development Center (NIDC) at ORNL coordinates isotope production across the many facilities and manages the business operations of the sale and distribution of isotopes.

  3. Isotope Development & Production | Nuclear Science | ORNL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Medical Radioisotope Radiochemical Separation & Processing Strategic Isotope Production Super Heavy Element Discovery Nuclear Security Science & Technology Nuclear Systems...

  4. Improving Home Automation by Discovering Regularly Occurring Device Usage Patterns

    E-Print Network [OSTI]

    Cook, Diane J.

    Improving Home Automation by Discovering Regularly Occurring Device Usage Patterns Edwin O in an environment can be mined to discover significant patterns, which an intelligent agent could use to automate of two prediction algorithms, thus demonstrating multiple uses for a home automation system. Finally, we

  5. accident excursion occurring: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    accident excursion occurring First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Annual Report of Railroad...

  6. Isotope Cancer Treatment Research at LANL

    ScienceCinema (OSTI)

    Weidner, John; Nortier, Meiring

    2014-06-02T23:59:59.000Z

    Los Alamos National Laboratory has produced medical isotopes for diagnostic and imaging purposes for more than 30 years. Now LANL researchers have branched out into isotope cancer treatment studies. New results show that an accelerator-based approach can produce clinical trial quantities of actinium-225, an isotope that has promise as a way to kill tumors without damaging surrounding healthy cells.

  7. Level densities of nickel isotopes: microscopic theory versus experiment

    E-Print Network [OSTI]

    M. Bonett-Matiz; Abhishek Mukherjee; Y. Alhassid

    2013-05-01T23:59:59.000Z

    We apply a spin-projection method to calculate microscopically the level densities of a family of nickel isotopes $^{59-64}$Ni using the shell model Monte Carlo approach in the complete $pfg_{9/2}$ shell. Accurate ground-state energies of the odd-mass nickel isotopes, required for the determination of excitation energies, are determined using the Green's function method recently introduced to circumvent the odd particle-number sign problem. Our results are in excellent agreement with recent measurements based on proton evaporation spectra and with level counting data at low excitation energies. We also compare our results with neutron resonance data, assuming equilibration of parity and a spin-cutoff model for the spin distribution at the neutron binding energy, and find good agreement with the exception of $^{63}$Ni.

  8. Multiple sulfur isotope signatures of sulfite and thiosulfate reduction by the model dissimilatory sulfate-reducer, Desulfovibrio alaskensis str. G20

    E-Print Network [OSTI]

    Leavitt, William D.

    Dissimilatory sulfate reduction serves as a key metabolic carbon remineralization process in anoxic marine environments. Sulfate reducing microorganisms can impart a wide range in mass-dependent sulfur isotopic fractionation. ...

  9. Atomic-scale characterization of germanium isotopic multilayers by atom probe tomography

    SciTech Connect (OSTI)

    Shimizu, Y.; Takamizawa, H.; Toyama, T.; Inoue, K.; Nagai, Y. [Oarai Center, Institute for Materials Research, Tohoku University, 2145-2 Narita, Oarai, Ibaraki 311-1313 (Japan); Kawamura, Y.; Uematsu, M.; Itoh, K. M. [School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Haller, E. E. [University of California at Berkeley and Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

    2013-01-14T23:59:59.000Z

    We report comparison of the interfacial sharpness characterization of germanium (Ge) isotopic multilayers between laser-assisted atom probe tomography (APT) and secondary ion mass spectrometry (SIMS). An alternating stack of 8-nm-thick naturally available Ge layers and 8-nm-thick isotopically enriched {sup 70}Ge layers was prepared on a Ge(100) substrate by molecular beam epitaxy. The APT mass spectra consist of clearly resolved peaks of five stable Ge isotopes ({sup 70}Ge, {sup 72}Ge, {sup 73}Ge, {sup 74}Ge, and {sup 76}Ge). The degree of intermixing at the interfaces between adjacent layers was determined by APT to be around 0.8 {+-} 0.1 nm which was much sharper than that obtained by SIMS.

  10. Neutrino Masses

    E-Print Network [OSTI]

    Christian Weinheimer; Kai Zuber

    2013-09-04T23:59:59.000Z

    The various experiments on neutrino oscillation evidenced that neutrinos have indeed non-zero masses but cannot tell us the absolute neutrino mass scale. This scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing constraints on the sum of all neutrino masses from cosmological observations two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double $\\beta$-decay and the direct neutrino mass search by investigating single $\\beta$-decays or electron captures. The former method is not only sensitive to neutrino masses but also probes the Majorana character of neutrinos and thus lepton number violation with high sensitivity. Currently quite a few experiments with different techniques are being constructed, commissioned or are even running, which aim for a sensitivity on the neutrino mass of {\\cal O}(100) meV. The principle methods and these experiments will be discussed in this short review.

  11. Hydrogen Cylinder Storage Array Explosion Evaluations at the High Flux Isotope Reactor

    SciTech Connect (OSTI)

    Cook, David Howard [ORNL] [ORNL; Griffin, Frederick P [ORNL] [ORNL; Hyman III, Clifton R [ORNL] [ORNL

    2010-01-01T23:59:59.000Z

    The safety analysis for a recently-installed cold neutron source at the High Flux Isotope Reactor (HFIR) involved evaluation of potential explosion consequences from accidental hydrogen jet releases that could occur from an array of hydrogen cylinders. The scope of the safety analysis involved determination of the release rate of hydrogen, the total quantity of hydrogen assumed to be involved in the explosion, the location of an ignition point or center of the explosion from receptors of interest, and the peak overpressure at the receptors. To evaluate the total quantity of hydrogen involved in the explosion, a 2D model was constructed of the jet concentration and a radial-axial integral over the jet cloud from the centerline to the flammability limit of 4% was used to determine the hydrogen mass to be used as a source term. The location of the point source was chosen as the peak of the jet centerline concentration profile. Consequences were assessed using a combination of three methods for estimating local overpressure as a function of explosion source strength and distance: the Baker-Strehlow method, the TNT-equivalence method, and the TNO method. Results from the explosions were assessed using damage estimates in screening tables for buildings and industrial equipment.

  12. High-precision optical measurements of 13 isotope ratios in organic compounds at

    E-Print Network [OSTI]

    Zare, Richard N.

    range with an average precision of 0.95 and 0.67 for ethane and propane, respec- tively. The calibrated accuracy for methane, ethane, and propane is within 3 of the values determined using isotope ratio mass place in chemistry, especially in geochemistry, for determining reaction mechanisms and pro- viding

  13. RAPID COMMUNICATION / COMMUNICATION RAPIDE Validation of Sr isotopes in otoliths by laser

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    RAPID COMMUNICATION / COMMUNICATION RAPIDE Validation of Sr isotopes in otoliths by laser ablation à plasma inductif avec multicollecteur après ablation au laser (LA-MC-ICPMS) et par spectrométrie de ratios using laser abla- tion multicollector inductively coupled plasma mass spectrometry (LA

  14. Naturally occurring crystalline phases: analogues for radioactive waste forms

    SciTech Connect (OSTI)

    Haaker, R.F.; Ewing, R.C.

    1981-01-01T23:59:59.000Z

    Naturally occurring mineral analogues to crystalline phases that are constituents of crystalline radioactive waste forms provide a basis for comparison by which the long-term stability of these phases may be estimated. The crystal structures and the crystal chemistry of the following natural analogues are presented: baddeleyite, hematite, nepheline; pollucite, scheelite;sodalite, spinel, apatite, monazite, uraninite, hollandite-priderite, perovskite, and zirconolite. For each phase in geochemistry, occurrence, alteration and radiation effects are described. A selected bibliography for each phase is included.

  15. Radioactive Mineral Occurences in Nevada | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I GeothermalPotentialBiopowerSolidGenerationMethodInformationeNevadaRadioactive Mineral Occurences in

  16. Isotopic distribution of fission fragments in collisions between 238U beam and 9Be and 12C targets at 24 MeV/u

    E-Print Network [OSTI]

    O. Delaune; F. Farget; O. B. Tarasov; A. M. Amthor; B. Bastin; D. Bazin; B. Blank; L. Cacéres; A. Chbihi; B. Fernandez-Dominguez; S. Grevy; O. Kamalou; S. Lukyanov; W. Mittig; D. J. Morrissey; J. Pereira; L. Perrot; M. -G. Saint-Laurent; H. Savajols; B. M. Sherrill; C. Stodel; J. C. Thomas; A. C. Villari

    2013-02-11T23:59:59.000Z

    Inverse kinematics coupled to a high-resolution spectrometer is used to investigate the isotopic yields of fission fragments produced in reactions between a 238U beam at 24 MeV/u and 9Be and 12C targets. Mass, atomic number and isotopic distributions are reported for the two reactions. These informations give access to the neutron excess and the isotopic distribution widths, which together with the atomic-number and mass distributions are used to investigate the fusion-fission dynamics.

  17. Measurement of Ultra-Low Potassium Contaminations with Accelerator Mass Spectrometry

    E-Print Network [OSTI]

    K. J. Dong

    2007-05-01T23:59:59.000Z

    Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Among the radio-isotopes, $\\k40$ is one of the most abundant and yet whose signatures are difficult to reject. Procedures were devised to measure trace potassium concentrations in the inorganic salt CsI as well as in organic liquid scintillator (LS) with Accelerator Mass Spectrometry (AMS), giving, respectively, the $\\k40$-contamination levels of $\\sim 10^{-10}$ and $\\sim 10^{-13}$ g/g. Measurement flexibilities and sensitivities are improved over conventional methods. The projected limiting sensitivities if no excess of potassium signals had been observed over background are $8 \\times 10^{-13}$ g/g and $3 \\times 10^{-17}$ g/g for the CsI and LS, respectively. Studies of the LS samples indicate that the radioactive contaminations come mainly in the dye solutes, while the base solvents are orders of magnitude cleaner. The work demonstrate the possibilities of measuring naturally-occurring isotopes with the AMS techniques.

  18. Isotopic Analysis of Uranium in NIST SRM Glass by Femtosecond Laser Ablation

    SciTech Connect (OSTI)

    Duffin, Andrew M.; Hart, Garret L.; Hanlen, Richard C.; Eiden, Gregory C.

    2013-05-19T23:59:59.000Z

    We employed femtosecond Laser Ablation Multicollector Inductively Coupled Mass Spectrometry for the 11 determination of uranium isotope ratios in a series of standard reference material glasses (NIST 610, 612, 614, and 12 616). This uranium concentration in this series of SRM glasses is a combination of isotopically natural uranium in 13 the materials used to make the glass matrix and isotopically depleted uranium added to increase the uranium 14 elemental concentration across the series. Results for NIST 610 are in excellent agreement with literature values. 15 However, other than atom percent 235U, little information is available for the remaining glasses. We present atom 16 percent and isotope ratios for 234U, 235U, 236U, and 238U for all four glasses. Our results show deviations from the 17 certificate values for the atom percent 235U, indicating the need for further examination of the uranium isotopes in 18 NIST 610-616. Our results are fully consistent with a two isotopic component mixing between the depleted 19 uranium spike and natural uranium in the bulk glass.

  19. Measurement of the isotope fractionation associated with diffusion of carbon dioxide in aqueous solution

    SciTech Connect (OSTI)

    O'Leary, M.H.

    1984-01-01T23:59:59.000Z

    An isotope ratio method has been developed which permits measurement of the isotope fractionation associated with diffusion of solutes in solution. Diffusion is conducted in a diaphragm cell of the type usually used for tracer diffusion measurements. The difference in isotopic composition of the solute before and after the diffusion process is measured by means of an isotope ratio mass spectrometer. This difference is then used to calculate the ratio of diffusion coefficients for the two isotopic species. By this method the isotope fractionation associated with diffusion of CO/sub 2/ dissolved in water has been found to be D(/sup 12/CO/sub 2/)/D(/sup 13/CO/sub 2/) = 1.0007 +/- 0.0002 at 25/sup 0/C. The same series of experiments also produced a value of 1.0011 for the ratio of solubilities of /sup 12/CO/sub 2/ and /sup 13/CO/sub 2/ in water at 30/sup 0/C, in excellent agreement with the published value. 23 references, 1 table.

  20. Carbon isotope fractionation in plants. Final technical report, June 1, 1983-May 31, 1986

    SciTech Connect (OSTI)

    O'Leary, M.H.

    1986-09-01T23:59:59.000Z

    Plants fractionate carbon isotopes during photosynthesis in ways which reflect photosynthetic pathway and environment. The object of our work is to develop methods for using this isotope fractionation to give information about how the components of the carbon fixation process (diffusion, carboxylation, etc.) vary with species, environment, and other variables. These studies provide important information regarding environmental control of the efficiency of photosynthesis as well as information regarding changes in photosynthesis which can be expected in coming years as atmospheric carbon dioxide levels increase. To this end, we have developed quantitative models for carbon isotope fractionation which describe this process in terms of rates of diffusion, carboxylation, and other steps. We have developed experimental approaches which focus on the initial events in carbon dioxide fixation and enable us to determine the relative rates of the various individual processes involved. Our approaches are unique in that they provide a view of the carbon isotope fractionation process over a period of a few hours, whereas combustion methods used by previous investigators provide only a long-term view of the carbon isotope fractionation process. We have also developed other methods using stable isotopes which rely on NMR and mass spectral measurements to study plant metabolism. 61 refs., 5 figs., 4 tabs.

  1. Resolutions of Problems that Occurred in SPEAR3 Magnet Production

    SciTech Connect (OSTI)

    Li, Nanyang

    2005-05-27T23:59:59.000Z

    Some problems occurred during the SPEAR3 magnet production at IHEP, China. It was very hard to find resolution from existing knowledge of those problems. It was possible that similar problems might have happen in building accelerator magnet in other institutes before, but they were not addressed in public papers. These problems were discussed and solved by engineers from both SLAC and IHEP after conducting certain experiments. Traditionally, the magnet design and measurement data have been always well documented and addressed in papers, but the production experiences have not been recorded adequately. It is the goal of this paper to record the problems and their resolutions during SPEAR3 magnet production at IHEP China, which will certainly benefit future magnet projects.

  2. Stable Isotope Enrichment Capabilities at ORNL

    SciTech Connect (OSTI)

    Egle, Brian [ORNL; Aaron, W Scott [ORNL; Hart, Kevin J [ORNL

    2013-01-01T23:59:59.000Z

    The Oak Ridge National Laboratory (ORNL) and the US Department of Energy Nuclear Physics Program have built a high-resolution Electromagnetic Isotope Separator (EMIS) as a prototype for reestablishing a US based enrichment capability for stable isotopes. ORNL has over 60 years of experience providing enriched stable isotopes and related technical services to the international accelerator target community, as well as medical, research, industrial, national security, and other communities. ORNL is investigating the combined use of electromagnetic and gas centrifuge isotope separation technologies to provide research quantities (milligram to several kilograms) of enriched stable isotopes. In preparation for implementing a larger scale production facility, a 10 mA high-resolution EMIS prototype has been built and tested. Initial testing of the device has simultaneously collected greater than 98% enriched samples of all the molybdenum isotopes from natural abundance feedstock.

  3. Stable Isotope Protocols: Sampling and Sample Processing

    E-Print Network [OSTI]

    Levin, Lisa A; Currin, Carolyn

    2012-01-01T23:59:59.000Z

    plants, benthic microalgae [BMI], benthic macroalgae) andin a dessicator, prior to analysis. A.2 Benthic microalgaeBenthic microalgae (BMI) can be collected for isotope

  4. EIS-0249: Medical Isotopes Production Project

    Broader source: Energy.gov [DOE]

    This EIS evaluates the potential environmental impacts of a proposal to establish a production capability for molybdenum-99 (Mo-99) and related medical isotopes.

  5. Integration of Nontraditional Isotopic Systems Into Reaction...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Water-Rock Interaction, and Impacts of Water Chemistry on Reservoir Sustainability Integration of Nontraditional Isotopic Systems Into Reaction-Transport Models of EGS For...

  6. Atom trap trace analysis of krypton isotopes

    SciTech Connect (OSTI)

    Bailey, K.; Chen, C. Y.; Du, X.; Li, Y. M.; Lu, Z.-T.; O'Connor, T. P.; Young, L.

    1999-11-17T23:59:59.000Z

    A new method of ultrasensitive isotope trace analysis has been developed. This method, based on the technique of laser manipulation of neutral atoms, has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton gas sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. This method is free of contamination from other isotopes and elements and can be applied to several different isotope tracers for a wide range of applications. The demonstrated detection efficiency is 1 x 10{sup {minus}7}. System improvements could increase the efficiency by many orders of magnitude.

  7. Stable Isotope Fractionations in Biogeochemical Reactive Transport

    E-Print Network [OSTI]

    Druhan, Jennifer Lea

    2012-01-01T23:59:59.000Z

    34 S fractionation . Summary A mesoscale study of isotopicion exchange and ! 44 Ca . A mesoscale study of isotopicmodeling and ! 34 S . A mesoscale study of isotopic

  8. Method for isotope enrichment by photoinduced chemiionization

    DOE Patents [OSTI]

    Dubrin, James W. (Walnut Creek, CA)

    1985-01-01T23:59:59.000Z

    Isotope enrichment, particularly .sup.235 U enrichment, is achieved by irradiating an isotopically mixed vapor feed with radiant energy at a wavelength or wavelengths chosen to selectively excite the species containing a desired isotope to a predetermined energy level. The vapor feed if simultaneously reacted with an atomic or molecular reactant species capable of preferentially transforming the excited species into an ionic product by a chemiionization reaction. The ionic product, enriched in the desired isotope, is electrostatically or electromagnetically extracted from the reaction system.

  9. Time of flight mass spectrometer

    DOE Patents [OSTI]

    Ulbricht, Jr., William H. (Arvada, CO)

    1984-01-01T23:59:59.000Z

    A time-of-flight mass spectrometer is described in which ions are desorbed from a sample by nuclear fission fragments, such that desorption occurs at the surface of the sample impinged upon by the fission fragments. This configuration allows for the sample to be of any thickness, and eliminates the need for complicated sample preparation.

  10. Heat and mass exchanger

    DOE Patents [OSTI]

    Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

    2007-09-18T23:59:59.000Z

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  11. Heat and mass exchanger

    DOE Patents [OSTI]

    Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

    2011-06-28T23:59:59.000Z

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  12. Neutrinoless Double Beta Decay and Neutrino Masses

    E-Print Network [OSTI]

    Michael Duerr

    2012-06-04T23:59:59.000Z

    Neutrinoless double beta decay is a promising test for lepton number violating physics beyond the standard model of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between neutrinoless double beta decay and Majorana neutrino masses provided by the so-called Schechter--Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate neutrinoless double beta decay from unknown nuclear background using only one isotope, i.e., within one experiment.

  13. Neutrinoless double beta decay and neutrino masses

    SciTech Connect (OSTI)

    Duerr, Michael [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

    2012-07-27T23:59:59.000Z

    Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.

  14. Protein expression and isotopic enrichment based on induction of the Entner-Doudoroff pathway in Escherichia coli

    SciTech Connect (OSTI)

    Refaeli, Bosmat [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv (Israel)] [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv (Israel); Goldbourt, Amir, E-mail: amirgo@post.tau.ac.il [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv (Israel)] [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv (Israel)

    2012-10-12T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer The Entner-Doudoroff pathway is induced during protein expression in E. coli. Black-Right-Pointing-Pointer 1-{sup 13}C-gluconate and {sup 15}NH{sub 4}Cl provide a carbonyl-amide protein backbone labeling scheme. Black-Right-Pointing-Pointer The enrichment pattern is determined by nuclear magnetic resonance. -- Abstract: The Entner-Doudoroff pathway is known to exist in many organisms including bacteria, archea and eukarya. Although the common route for carbon catabolism in Escherichia coli is the Embden-Meyerhof-Parnas pathway, it was shown that gluconate catabolism in E. coli occurs via the Entner-Doudoroff pathway. We demonstrate here that by supplying BL21(DE3) competent E.coli cells with gluconate in a minimal growth medium, protein expression can be induced. Nuclear magnetic resonance data of over-expressed ubiquitin show that by using [1-{sup 13}C]-gluconate as the only carbon source, and {sup 15}N-enriched ammonium chloride, sparse isotopic enrichment in the form of a spin-pair carbonyl-amide backbone enrichment is obtained. The specific amino acid labeling pattern is analyzed and is shown to be compatible with Entner-Doudoroff metabolism. Isotopic enrichment serves as a key factor in the biophysical characterization of proteins by various methods including nuclear magnetic resonance, mass spectrometry, infrared spectroscopy and more. Therefore, the method presented here can be applied to study proteins by obtaining sparse enrichment schemes that are not based on the regular glycolytic pathway, or to study the Entner-Doudoroff metabolism during protein expression.

  15. Discovery of Isotopes of Elements with Z $\\ge$ 100

    E-Print Network [OSTI]

    M. Thoennessen

    2012-03-09T23:59:59.000Z

    Currently, 163 isotopes of elements with Z $\\ge$ 100 have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  16. Gamma Spectrum from Neutron Capture on Tungsten Isotopes

    E-Print Network [OSTI]

    Hurst, Aaron

    2011-01-01T23:59:59.000Z

    FROM NEUTRON CAPTURE ON TUNGSTEN ISOTOPES A. M. HURST ?1,2 ,capture on the stable tungsten isotopes is presented, withknown decay schemes of the tungsten isotopes from neutron

  17. Method and apparatus for noble gas atom detection with isotopic selectivity

    DOE Patents [OSTI]

    Hurst, G. Samuel (Oak Ridge, TN); Payne, Marvin G. (Harriman, TN); Chen, Chung-Hsuan (Knoxville, TN); Parks, James E. (Oak Ridge, TN)

    1984-01-01T23:59:59.000Z

    Apparatus and methods of operation are described for determining, with isotopic selectivity, the number of noble gas atoms in a sample. The analysis is conducted within an evacuated chamber which can be isolated by a valve from a vacuum pumping system capable of producing a pressure of 10.sup.-8 Torr. Provision is made to pass pulses of laser beams through the chamber, these pulses having wavelengths appropriate for the resonance ionization of atoms of the noble gas under analysis. A mass filter within the chamber selects ions of a specific isotope of the noble gas, and means are provided to accelerate these selected ions sufficiently for implantation into a target. Specific types of targets are discussed. An electron measuring device produces a signal relatable to the number of ions implanted into the target and thus to the number of atoms of the selected isotope of the noble gas removed from the gas sample. The measurement can be continued until a substantial fraction, or all, of the atoms in the sample have been counted. Furthermore, additional embodiments of the apparatus are described for bunching the atoms of a noble gas for more rapid analysis, and for changing the target for repetitive cycling of the gas in the chamber. The number of repetitions of the cyclic steps depend upon the concentration of the isotope of interest, the separative efficiency of the mass filter, etc. The cycles are continued until a desired selectivity is achieved. Also described are components and a method of operation for a pre-enrichment operation for use when an introduction of a total sample would elevate the pressure within the chamber to levels in excess of those for operation of the mass filter, specifically a quadrupole mass filter. Specific examples of three noble gas isotope analyses are described.

  18. Solvent dependence of the carbon kinetic isotope effect on the decarboxylation of 4-pyridylacetic acid. A model for enzymatic decarboxylations

    SciTech Connect (OSTI)

    Marlier, J.F.; O'Leary, M.H.

    1986-08-06T23:59:59.000Z

    Carbon kinetic isotope effects have been measured for the decarboxylation of 4-pyridylacetic acid in pure water and in water-dioxane mixtures at 25/sup 0/C. The isotope effects are k/sup 12//k/sup 13/ = 1.064 in 75% dioxane, 1.060 in 50% dioxane, 1.056 in 25% dioxane, and 1.057 in pure water. The decrease in kinetic isotope effect parallels a more dramatic 4000-fold decrease in the observed first-order rate constant on going from 75% dioxane to pure water. No solvent isotope effect is observed in 50% water/dioxane, and as expected, the carbon isotope effect is the same in 50% D/sub 2/O/dioxane as in 50% H/sub 2/O/dioxane. The reaction appears to occur in a single step, without appreciable proton movement. The variation in rate is attributed to variations in the degree of transition-state solvation with only very small changes in ground-state effects and in the degree of carbon-carbon bond breaking in the transition state. These results indicate that the magnitudes of isotope effects observed in model reactions in H/sub 2/O are an appropriate model for magnitudes of isotope effects in enzymatic decarboxylations.

  19. Tropical Pacific nutrient dynamics in the modern and pleistocene ocean : insights from the nitrogen isotope system

    E-Print Network [OSTI]

    Rafter, Patrick Anthony

    2009-01-01T23:59:59.000Z

    nitrogen isotopes, an enrichment that is conventionallyisotopes upon denitrification also imparts a strong isotopic enrichment

  20. Isotopes Tell Origin and Operation of the Sun

    E-Print Network [OSTI]

    O. Manuel; Sumeet A. Kamat; Michael Mozina

    2005-09-28T23:59:59.000Z

    The Iron Sun formed on the collapsed core of a supernova and now acts as a magnetic plasma diffuser, as did the precursor star, separating ions by mass. This process covers the solar surface with lightweight elements and with lighter isotopes of each element. Running difference images expose rigid, iron-rich structures below the fluid photosphere made of lightweight elements. The energy source for the Sun and ordinary stars seems to be neutron-emission and neutron-decay, with partial fusion of the decay product, rather than simple fusion of hydrogen into helium or heavier elements. Neutron-emission from the solar core and neutron-decay generate about sixty five percent of solar luminosity and H-fusion generates about thirty-five percent. The upward flow of H ions maintains mass-separation in the Sun. Only about one percent of this neutron decay product survives its upward journey to depart as solar-wind hydrogen.

  1. Geochemical and carbon isotopic studies of crude oil destruction, bitumen precipitation, and sulfate reduction in the deep Smackover Formation

    SciTech Connect (OSTI)

    Sassen, R. (Louisiana State Univ., Baton Rouge (USA))

    1988-01-01T23:59:59.000Z

    Crude oil generated by the Lower Smackover source facies migrated to Upper Smackover reservoirs where slow thermal cracking of crude oil resulted in the formation of gas-condensate and late solid bitumen. Ultimately, only pyrobitumen, methane, and nonhydrocarbon gases including hydrogen sulfide persist in the deepest Smackover reservoirs. The carbon isotopic compositions of crude oils became heavier during crude oil destruction. The carbon isotopic compositions of asphaltenes, NSO-compounds, and saturated hydrocarbons in late solid bitumen and the Lower Smackover source facies became isotopically lighter during crude oil destruction. It is suggested that some isotopically-light components from crude oils were incorporated in late solid bitumen by reactions involving thermochemical sulfate reduction. Thermochemical sulfate reduction and crude oil destruction occurred over a long span of geologic time at temperatures in the 120-150C range.

  2. Spatial periphery of lithium isotopes

    SciTech Connect (OSTI)

    Galanina, L. I., E-mail: galan_lidiya@mail.ru; Zelenskaja, N. S. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2013-12-15T23:59:59.000Z

    The spatial structure of lithium isotopes is studied with the aid of the charge-exchange and (t, p) reactions on lithium nuclei. It is shown that an excited isobaric-analog state of {sup 6}Li (0{sup +}, 3.56MeV) has a halo structure formed by a proton and a neutron, that, in the {sup 9}Li nucleus, there is virtually no neutron halo, and that {sup 11}Li is a Borromean nucleus formed by a {sup 9}Li core and a two-neutron halo manifesting itself in cigar-like and dineutron configurations.

  3. Isotopic Scaling in Nuclear Reactions

    E-Print Network [OSTI]

    M. B. Tsang; W. A. Friedman; C. K. Gelbke; W. G. Lynch; G. Verde; H. Xu

    2001-03-26T23:59:59.000Z

    A three parameter scaling relationship between isotopic distributions for elements with Z$\\leq 8$ has been observed that allows a simple description of the dependence of such distributions on the overall isospin of the system. This scaling law (termed iso-scaling) applies for a variety of reaction mechanisms that are dominated by phase space, including evaporation, multifragmentation and deeply inelastic scattering. The origins of this scaling behavior for the various reaction mechanisms are explained. For multifragmentation processes, the systematics is influenced by the density dependence of the asymmetry term of the equation of state.

  4. Stable carbon and nitrogen isotope enrichment in primate tissues

    E-Print Network [OSTI]

    Crowley, Brooke E.; Carter, Melinda L.; Karpanty, Sarah M.; Zihlman, Adrienne L.; Koch, Paul L.; Dominy, Nathaniel J.

    2010-01-01T23:59:59.000Z

    carbon and nitrogen isotope enrichment in primate tissuesfactor (a) and isotope enrichment values (e), which provideisotope values from different modern primate tissues. Additionally, using these mean apparent enrichment

  5. CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope...

    Broader source: Energy.gov (indexed) [DOE]

    Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR...

  6. CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope...

    Broader source: Energy.gov (indexed) [DOE]

    Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C to DOE G...

  7. aluminium isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CERN Preprints Summary: Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For...

  8. americium isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CERN Preprints Summary: Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For...

  9. activated bismuth isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CERN Preprints Summary: Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For...

  10. astatine isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CERN Preprints Summary: Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For...

  11. A Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal...

    Open Energy Info (EERE)

    Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal System Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Helium Isotope...

  12. Isotopic Analysis- Fluid At Dixie Valley Geothermal Area (Kennedy...

    Open Energy Info (EERE)

    geothermal resources with deep, fault hosted permeable fluid flow pathways and the helium Isotopic composition of the surface fluids. The authors suggest that helium isotopes...

  13. Fractionation of Oxygen Isotopes in Phosphate during its Interactions...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides. Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides....

  14. applied isotope techniques: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    M. 22 Applied Radiation and Isotopes 55 (2001) 707713 Bronchial dosimeter for radon progeny Biology and Medicine Websites Summary: Applied Radiation and Isotopes 55 (2001)...

  15. Isoscaling in Reactions on Enriched Tin Isotopes and Nuclear Symmetry Energy

    E-Print Network [OSTI]

    A. S. Danagulyan; A. R. Balabekyan; G. H. Hovhannisyan; N. A. Demekhina; I. Adam; V. G. Kalinnikov; M. I. Krivopustov; V. M. Tsoupko-Sitnikov

    2008-05-19T23:59:59.000Z

    Isospin effects in 12C ion induced reactions on enriched tin isotopes are investigated. The isoscaling parameter B is determined for different mass regions of product nuclei. It is shown that the isoscaling parameter is sensitive to the formation mechanism of products, and increases as the difference in the asymmetry is increasing. Using the exitatation energy obtained with the catcher technique temperatures, density ratio ro/ro0 for product nuclei in different mass regions and the values of symmetry energy coefficient for light mass regions of product nuclei for proton and deuteron induced reactions are determined.

  16. Investigation of high temperature gaseous species by Knudsen cell mass spectrometry above the condensed systems Cu-Y-Ru-C, Ag-Y-Ru-C, and Au-Y- Ru-C

    E-Print Network [OSTI]

    Wilhite, Dale Wayne

    1988-01-01T23:59:59.000Z

    of the total ion intensities listed in Tables 2 through 5, + + except those for RuC and YC2, were calculated by dividing the individual isotopic species by the isotopic abundance of that species according to Equation 1, where I is the total intensity of all... not be used because their mass to charge ratios overlap. For these iona, an + algebraic equation was used which compared the ratios of YC (Mass 113), YC2 (Mass 114), RuC (Mass 113), and RuC (Mass 114). The + + + calculated isotopic abundances...

  17. The neutron star mass distribution

    SciTech Connect (OSTI)

    Kiziltan, Bülent [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kottas, Athanasios; De Yoreo, Maria [Department of Applied Mathematics and Statistics, University of California, Santa Cruz, CA 95064 (United States); Thorsett, Stephen E., E-mail: bkiziltan@cfa.harvard.edu [Department of Astronomy and Astrophysics, University of California and UCO/Lick Observatory, Santa Cruz, CA 95064 (United States)

    2013-11-20T23:59:59.000Z

    In recent years, the number of pulsars with secure mass measurements has increased to a level that allows us to probe the underlying neutron star (NS) mass distribution in detail. We critically review the radio pulsar mass measurements. For the first time, we are able to analyze a sizable population of NSs with a flexible modeling approach that can effectively accommodate a skewed underlying distribution and asymmetric measurement errors. We find that NSs that have evolved through different evolutionary paths reflect distinctive signatures through dissimilar distribution peak and mass cutoff values. NSs in double NS and NS-white dwarf (WD) systems show consistent respective peaks at 1.33 M {sub ?} and 1.55 M {sub ?}, suggesting significant mass accretion (?m ? 0.22 M {sub ?}) has occurred during the spin-up phase. The width of the mass distribution implied by double NS systems is indicative of a tight initial mass function while the inferred mass range is significantly wider for NSs that have gone through recycling. We find a mass cutoff at ?2.1 M {sub ?} for NSs with WD companions, which establishes a firm lower bound for the maximum NS mass. This rules out the majority of strange quark and soft equation of state models as viable configurations for NS matter. The lack of truncation close to the maximum mass cutoff along with the skewed nature of the inferred mass distribution both enforce the suggestion that the 2.1 M {sub ?} limit is set by evolutionary constraints rather than nuclear physics or general relativity, and the existence of rare supermassive NSs is possible.

  18. Thermal Conductivity and Large Isotope Effect in GaN from First Principles

    SciTech Connect (OSTI)

    Lindsay, L. [Naval Research Lab. (NRL), Washington, DC (United States); Broido, D. A. [Boston College, Chestnut Hill, MA (United States); Reinecke, T. L. [Naval Research Lab. (NRL), Washington, DC (United States)

    2012-08-01T23:59:59.000Z

    We present atomistic first principles results for the lattice thermal conductivity of GaN and compare them to those for GaP, GaAs, and GaSb. In GaN we find a large increase to the thermal conductivity with isotopic enrichment, ~65% at room temperature. We show that both the high thermal conductivity and its enhancement with isotopic enrichment in GaN arise from the weak coupling of heat-carrying acoustic phonons with optic phonons. This weak scattering results from stiff atomic bonds and the large Ga to N mass ratio, which give phonons high frequencies and also a pronounced energy gap between acoustic and optic phonons compared to other materials. Rigorous understanding of these features in GaN gives important insights into the interplay between intrinsic phonon-phonon scattering and isotopic scattering in a range of materials.

  19. Pygmy resonance and low-energy enhancement in the $?$-ray strength functions of Pd~isotopes

    E-Print Network [OSTI]

    Tomas Kvalheim Eriksen; Hilde-Therese Nyhus; Magne Guttormsen; Andreas Görgen; Ann-Cecilie Larsen; Therese Renstrøm; Inger-Eli Ruud; Sunniva Siem; Heidi Kristine Toft; Gry Merete Tveten; Jonathan Wilson

    2014-08-22T23:59:59.000Z

    An unexpected enhancement in the $\\gamma$-ray strength function, as compared to the low energy tail of the Giant Dipole Resonance (GDR), has been observed for Sc, Ti, V, Fe and Mo isotopes for $E_\\gamma4$ MeV, which is interpreted as a PDR centered at $E_{\\gamma}\\approx8$ MeV. An enhanced $\\gamma$-ray strength at low energies is also observed for $^{105}$Pd, which is the lightest isotope measured in this work. Further, the results correspond and agree very well with the observations from the Cd isotopes, and support the suggested transitional region for the onset of low-energy enhancement with decreasing mass number. The neutron number dependency of the PDR strength is also evident.

  20. Manufactured Home Testing in Simulated and Naturally Occurring High Winds

    SciTech Connect (OSTI)

    W. D. Richins; T. K. Larson

    2006-08-01T23:59:59.000Z

    A typical double-wide manufactured home was tested in simulated and naturally occurring high winds to understand structural behavior and improve performance during severe windstorms. Seven (7) lateral load tests were conducted on a double-wide manufactured home at a remote field test site in Wyoming. An extensive instrumentation package monitored the overall behavior of the home and collected data vital to validating computational software for the manufactured housing industry. The tests were designed to approach the design load of the home without causing structural damage, thus allowing the behavior of the home to be accessed when the home was later exposed to high winds (to 80-mph). The data generally show near-linear initial system response with significant non-linear behavior as the applied loads increase. Load transfer across the marriage line is primarily compression. Racking, while present, is very small. Interface slip and shear displacement along the marriage line are nearly insignificant. Horizontal global displacements reached 0.6 inch. These tests were designed primarily to collect data necessary to calibrate a desktop analysis and design software tool, MHTool, under development at the Idaho National Laboratory specifically for manufactured housing. Currently available analysis tools are, for the most part, based on methods developed for “stick built” structures and are inappropriate for manufactured homes. The special materials utilized in manufactured homes, such as rigid adhesives used in the connection of the sheathing materials to the studs, significantly alter the behavior of manufactured homes under lateral loads. Previous full scale tests of laterally loaded manufactured homes confirm the contention that conventional analysis methods are not applicable. System behavior dominates the structural action of manufactured homes and its prediction requires a three dimensional analysis of the complete unit, including tiedowns. This project was sponsored by the US Department of Energy, US Department of Housing and Urban Development, and the Manufactured Housing Institute. The results of this research can lead to savings in annual losses of life and property by providing validated information to enable the advancement of code requirements and by developing engineering software that can predict and optimize wind resistance.

  1. MARK E. CONRAD Center for Isotope Geochemistry

    E-Print Network [OSTI]

    Ajo-Franklin, Jonathan

    with stable isotopes, fate and transport of groundwater contaminants, vadose zone hydrology, metal uptake by lichens, paleoclimatic patterns in California and stable isotope systematics of clay minerals. Geologist of gold property in the Mother Lode of California. Exploration Geologist (Anaconda Minerals Company; 6

  2. The Quest for the Heaviest Uranium Isotope

    E-Print Network [OSTI]

    S. Schramm; D. Gridnev; D. V. Tarasov; V. N. Tarasov; W. Greiner

    2012-01-17T23:59:59.000Z

    We study Uranium isotopes and surrounding elements at very large neutron number excess. Relativistic mean field and Skyrme-type approaches with different parametrizations are used in the study. Most models show clear indications for isotopes that are stable with respect to neutron emission far beyond N=184 up to the range of around N=258.

  3. Isotope separation by selective photodissociation of glyoxal

    DOE Patents [OSTI]

    Marling, John B. (Pleasanton, CA)

    1976-01-01T23:59:59.000Z

    Dissociation products, mainly formaldehyde and carbon monoxide, enriched in a desired isotope of carbon, oxygen, or hydrogen are obtained by the selective photodissociation of glyoxal wherein glyoxal is subjected to electromagnetic radiation of a predetermined wavelength such that photon absorption excites and induces dissociation of only those molecules of glyoxal containing the desired isotope.

  4. [Carbon isotope fractionation inplants]. Final report

    SciTech Connect (OSTI)

    O`Leary, M.H.

    1990-12-31T23:59:59.000Z

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  5. Isotope Enrichment Detection by Laser Ablation - Dual Tunable Diode Laser Absorption Spectrometry

    SciTech Connect (OSTI)

    Anheier, Norman C.; Bushaw, Bruce A.

    2009-07-01T23:59:59.000Z

    The rapid global expansion of nuclear energy is motivating the expedited development of new safeguards technology to mitigate potential proliferation threats arising from monitoring gaps within the uranium enrichment process. Current onsite enrichment level monitoring methods are limited by poor sensitivity and accuracy performance. Offsite analysis has better performance, but this approach requires onsite hand sampling followed by time-consuming and costly post analysis. These limitations make it extremely difficult to implement comprehensive safeguards accounting measures that can effectively counter enrichment facility misuse. In addition, uranium enrichment by modern centrifugation leads to a significant proliferation threat, since the centrifuge cascades can quickly produce a significant quantity of highly enriched uranium (HEU). The Pacific Northwest National Laboratory is developing an engineered safeguards approach having continuous aerosol particulate collection and uranium isotope analysis to provide timely detection of HEU production in a low enriched uranium facility. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy, to characterize the 235U/238U isotopic ratio by subtle differences in atomic absorption wavelengths arising from differences in each isotope’s nuclear mass, volume, and spin (hyperfine structure for 235U). Environmental sampling media is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes a 10 to 20-µm sample diameter. The ejected plasma forms a plume of atomic vapor. A plume for a sample containing uranium has atoms of the 235U and 238U isotopes present. Tunable diode lasers are directed through the plume to selectively excite each isotope and their presence is detected by monitoring absorbance signals on a shot-to-shot basis. Single-shot detection sensitivity approaching the femtogram range and abundance uncertainty less than 10% have been demonstrated with measurements on surrogate materials. In this paper we present measurement results on samples containing background materials (e.g., dust, minerals, soils) laced with micron-sized target particles having isotopic ratios ranging from 1 to 50%.

  6. ISOTOPES

    E-Print Network [OSTI]

    Lederer, C. Michael

    2013-01-01T23:59:59.000Z

    constructed to enrich liquid UF6 slightly as feed for thej) b. Optimum a. s: .X. UF6 feed, (kg per year) XBL 7912 -

  7. ISOTOPES

    E-Print Network [OSTI]

    Lederer, C. Michael

    2013-01-01T23:59:59.000Z

    lithium hydroxide (56, 14), A plant utilizing this reaction to produce 1000 kg per year of 99.99% 7Li at a price

  8. ISOTOPES

    E-Print Network [OSTI]

    Lederer, C. Michael

    2013-01-01T23:59:59.000Z

    §fissile materials in fast breeder reactors currently underwater reactor, FBR = fast breeder reactor. The band belowinc 1 udes heavy-water reactors, fast breeders, and 11

  9. ISOTOPES

    E-Print Network [OSTI]

    Lederer, C. Michael

    2013-01-01T23:59:59.000Z

    1978). United States Gas Centrifuge Program for 72. Energy~~;h)radius in a gas centrifuge with va 400 m/s. P 0 and U68,14) of a gas centrifuge with radius = 0.09145 m, length=

  10. ISOTOPES

    E-Print Network [OSTI]

    Lederer, C. Michael

    2013-01-01T23:59:59.000Z

    the columns used to separate UF5, which had a separativeof uranium by dissociation of UF5, by multiple vibrational

  11. Chlorine isotope investigation of natural attenuation of trichloroethene in an aerobic aquifer

    SciTech Connect (OSTI)

    Sturchio, N.C.; Heraty, L.J.; Huang, L.; Holt, B.D.; Abrajano, T.A. Jr. [Argonne National Lab., IL (United States)] [Argonne National Lab., IL (United States); Clausen, J.L. [Lockheed-Martin Energy Services, Inc., Kevil, KY (United States)] [Lockheed-Martin Energy Services, Inc., Kevil, KY (United States)

    1998-10-15T23:59:59.000Z

    Natural attenuation of chlorinated aliphatic hydrocarbons (CAHs) can be an important mechanism for groundwater remediation. It is difficult to determine the effectiveness of natural CAH attenuation from chemical analyses of groundwater samples because mixing, dispersion, and secondary reactions can mask the chemical evidence of attenuation. In this paper, the authors explore the application of stable chlorine isotope ratio measurements as a new tool for evaluating natural attenuation of CAHs. They report stable isotope ratios of chlorine in both trichloroethene (TCE) and inorganic chloride in groundwater from an aerobic aquifer beneath an extensively contaminated industrial site, the Paducah Gaseous Diffusion Plant in western Kentucky. Variations in the concentrations and chlorine isotope ratios of TCE and chloride in the groundwater are consistent with those expected from natural attenuation. These data support a model in which partial TCE degradation occurred in relatively impermeable, clay-rich sediments above the aquifer, and little or no further degradation of TCE occurred within the aquifer. A record of changing conditions within the TCE source area can be inferred from the spatial variation of chlorine isotope ratios for TCE and chloride within the plume.

  12. RAPID FUSION METHOD FOR DETERMINATION OF PLUTONIUM ISOTOPES IN LARGE RICE SAMPLES

    SciTech Connect (OSTI)

    Maxwell, S.

    2013-03-01T23:59:59.000Z

    A new rapid fusion method for the determination of plutonium in large rice samples has been developed at the Savannah River National Laboratory (Aiken, SC, USA) that can be used to determine very low levels of plutonium isotopes in rice. The recent accident at Fukushima Nuclear Power Plant in March, 2011 reinforces the need to have rapid, reliable radiochemical analyses for radionuclides in environmental and food samples. Public concern regarding foods, particularly foods such as rice in Japan, highlights the need for analytical techniques that will allow very large sample aliquots of rice to be used for analysis so that very low levels of plutonium isotopes may be detected. The new method to determine plutonium isotopes in large rice samples utilizes a furnace ashing step, a rapid sodium hydroxide fusion method, a lanthanum fluoride matrix removal step, and a column separation process with TEVA Resin? cartridges. The method can be applied to rice sample aliquots as large as 5 kg. Plutonium isotopes can be determined using alpha spectrometry or inductively-coupled plasma mass spectrometry (ICP-MS). The method showed high chemical recoveries and effective removal of interferences. The rapid fusion technique is a rugged sample digestion method that ensures that any refractory plutonium particles are effectively digested. The MDA for a 5 kg rice sample using alpha spectrometry is 7E-5 mBq g{sup -1}. The method can easily be adapted for use by ICP-MS to allow detection of plutonium isotopic ratios.

  13. Light stable isotope study of the Roosevelt Hot Springs thermal area, Southwestern Utah

    SciTech Connect (OSTI)

    Rohrs D.T.; Bowman, J.R.

    1980-05-01T23:59:59.000Z

    The isotopic composition of hydrogen, oxygen, and carbon has been determined for regional cold springs, thermal fluids, and rocks and minerals from the Roosevelt Hot Springs thermal area. The geothermal system has developed within plutonic granitic rocks and amphibolite facies gneiss, relying upon fracture-controlled permeability for the migration of the thermal fluids. Probably originating as meteoric waters in the upper elevations of the Mineral Mountains, the thermal waters sampled in the production wells display an oxygen isotopic shift of at least +1.2. Depletions of delta /sup 18/O in wole rock, K-feldspar, and biotite have a positive correlation with alteration intensity. W/R mass ratios, calculated from the isotopic shifts of rock and water, range up to 3.0 in a producing horizon of one well, although the K-feldspar has experienced only 30% exchange with the thermal waters. While veinlet quartz has equilibrated with the thermal waters, the /sup 18/O values of K-mica clay, an alteration product of plagioclase, mimic the isotopic composition of K-feldspar and whole rock. This suggests that locally small W/R ratios enable plagioclase to influence its alteration products by isotopic exchange.

  14. Europium, Samarium, and Neodymium Isotopic Fractions in Metal-Poor Stars

    E-Print Network [OSTI]

    Roederer, Ian U; Sneden, Christopher; Cowan, John J; Sobeck, Jennifer S; Pilachowski, Catherine A

    2007-01-01T23:59:59.000Z

    We have derived isotopic fractions of europium, samarium, and neodymium in two metal-poor giants with differing neutron-capture nucleosynthetic histories. These isotopic fractions were measured from new high resolution (R ~ 120,000), high signal-to-noise (S/N ~ 160-1000) spectra obtained with the 2dCoude spectrograph of McDonald Observatory's 2.7m Smith telescope. Synthetic spectra were generated using recent high-precision laboratory measurements of hyperfine and isotopic subcomponents of several transitions of these elements and matched quantitatively to the observed spectra. We interpret our isotopic fractions by the nucleosynthesis predictions of the stellar model, which reproduces s-process nucleosynthesis from the physical conditions expected in low-mass, thermally-pulsing stars on the AGB, and the classical method, which approximates s-process nucleosynthesis by a steady neutron flux impinging upon Fe-peak seed nuclei. Our Eu isotopic fraction in HD 175305 is consistent with an r-process origin by the ...

  15. Atomic vapor laser isotope separation of lead-210 isotope

    DOE Patents [OSTI]

    Scheibner, K.F.; Haynam, C.A.; Johnson, M.A.; Worden, E.F.

    1999-08-31T23:59:59.000Z

    An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207. 5 figs.

  16. Atomic vapor laser isotope separation of lead-210 isotope

    DOE Patents [OSTI]

    Scheibner, Karl F. (Tracy, CA); Haynam, Christopher A. (Pleasanton, CA); Johnson, Michael A. (Pleasanton, CA); Worden, Earl F. (Diablo, CA)

    1999-01-01T23:59:59.000Z

    An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207.

  17. Isotopic composition of Silurian seawater

    SciTech Connect (OSTI)

    Knauth, L.P.; Kealy, S.; Larimer, S.

    1985-01-01T23:59:59.000Z

    Direct isotopic analyses of 21 samples of the Silurian hydrosphere preserved as fluid inclusions in Silurian halite deposits in the Michigan Basin Salina Group yield delta/sup 18/O, deltaD ranging from 0.2 to +5.9 and -26 to -73, respectively. delta/sup 18/O has the same range as observed for modern halite facies evaporite waters and is a few per thousand higher than 100 analyses of fluid inclusions in Permian halite. deltaD is about 20 to 30 per thousand lower than modern and Permian examples. The trajectory of evaporating seawater on a deltaD-delta/sup 18/O diagram initially has a positive slope of 3-6, but hooks strongly downward to negative values, the shape of the hook depending upon humidity. Halite begins to precipitate at delta values similar to those observed for the most /sup 18/O rich fluid inclusions. Subsequent evaporation yields progressively more negative delta values as observed for the fluid inclusions. The fluid inclusion data can be readily explained in terms of evaporating seawater and are consistent with the degree of evaporation deduced from measured bromide profiles. These data are strongly inconsistent with arguments that Silurian seawater was 5.5 per thousand depleted in /sup 18/O. delta/sup 18/O for evaporite waters is systematically related to that of seawater, and does not show a -5.5 per thousand shift in the Silurian, even allowing for variables which affect the isotope evaporation trajectory. The lower deltaD may indicate a component of gypsum dehydration waters or may suggest a D-depleted Silurian hydrosphere.

  18. COMMENTS ON ANOMALOUS EFFECTS IN CHARGING OF PD POWDERS WITH HIGH DENSITY HYDROGEN ISOTOPES

    SciTech Connect (OSTI)

    Shanahan, K.

    2009-10-01T23:59:59.000Z

    In Kitamura, et al, Pd-containing materials are exposed to isotopes of hydrogen and anomalous results obtained. These are claimed to be a replication of another experiment conducted by Arata and Zhang. Erroneous basic assumptions are pointed out herein that alter the derived conclusions significantly. The final conclusion is that the reported results are likely normal chemistry combined with noise. Thus the claim to have proven that cold fusion is occurring in these systems is both premature and unlikely.

  19. Theory of the helium isotope shift

    E-Print Network [OSTI]

    Yerokhin, Vladimir A

    2015-01-01T23:59:59.000Z

    Theory of the isotope shift of the centroid energies of light few-electron atoms is reviewed. Numerical results are presented for the isotope shift of the $2^3P$-$2^3S$ and $2^1S$-$2^3S$ transition energies of $^3$He and $^4$He. By comparing theoretical predictions for the isotope shift with the experimental results, the difference of the squares of the nuclear charge radii of $^3$He and $^4$He, $\\delta R^2$, is determined with high accuracy.

  20. The plasma centrifuge: A compact, low cost, stable isotope separator. Phase 2 final technical report, September 15, 1991--September 14, 1995

    SciTech Connect (OSTI)

    Guss, W.

    1996-09-05T23:59:59.000Z

    Enriched stable isotopes are required for production of radionuclides as well as for research and diagnostic uses. Science Research Laboratory (SRL) has developed a plasma centrifuge for moderate throughput of enriched stable isotopes, such as {sup 13}C, {sup 17}O, {sup 18}O, and {sup 203}Tl, for medical as well as other applications. Dwindling isotope stocks have restricted the use of enriched isotopes and their associated labeled organic molecules in medical imaging to very few research facilities because of high costs of isotope separation. With the introduction of the plasma centrifuge separator, the cost per separated gram of even rarely occurring isotopes ({le} 1% natural abundance) is potentially many times lower than with other separation technologies (cryogenic distillation and calutrons). The centrifuge is a simple, robust, pulsed electrical discharge device that has successfully demonstrated isotope separation of small (mg) quantities of {sup 26}Mg. Based on the results of the Phase 2 program, modest enhancements to the power supplies and cooling systems, a centrifuge separator will have high repetition rate (60 pps) and high duty cycle (60%) to produce in one month kilogram quantities of highly enriched stable isotopes. The centrifuge may be used in stand-alone operation or could be used as a high-throughput pre-separation stage with calutrons providing the final separation.

  1. Influence of longitudinal isotope substitution on the thermal conductivity of carbon nanotubes: Results of nonequilibrium molecular dynamics and local density functional calculations

    SciTech Connect (OSTI)

    Leroy, Frédéric, E-mail: f.leroy@theo.chemie.tu-darmstadt.de; Böhm, Michael C., E-mail: boehm@theo.chemie.tu-darmstadt.de [Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt (Germany); Schulte, Joachim [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany)] [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany); Balasubramanian, Ganesh [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)] [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)

    2014-04-14T23:59:59.000Z

    We report reverse nonequilibrium molecular dynamics calculations of the thermal conductivity of isotope substituted (10,10) carbon nanotubes (CNTs) at 300 K. {sup 12}C and {sup 14}C isotopes both at 50% content were arranged either randomly, in bands running parallel to the main axis of the CNTs or in bands perpendicular to this axis. It is found that the systems with randomly distributed isotopes yield significantly reduced thermal conductivity. In contrast, the systems where the isotopes are organized in patterns parallel to the CNTs axis feature no reduction in thermal conductivity when compared with the pure {sup 14}C system. Moreover, a reduction of approximately 30% is observed in the system with the bands of isotopes running perpendicular to the CNT axis. The computation of phonon dispersion curves in the local density approximation and classical densities of vibrational states reveal that the phonon structure of carbon nanotubes is conserved in the isotope substituted systems with the ordered patterns, yielding high thermal conductivities in spite of the mass heterogeneity. In order to complement our conclusions on the {sup 12}C-{sup 14}C mixtures, we computed the thermal conductivity of systems where the {sup 14}C isotope was turned into pseudo-atoms of 20 and 40 atomic mass units.

  2. Helium isotopes in historical lavas from Mount Vesuvius Comment on `Noble gas isotopic ratios from historical lavas

    E-Print Network [OSTI]

    Graham, David W.

    Discussion Helium isotopes in historical lavas from Mount Vesuvius Comment on `Noble gas isotopic. Introduction Helium isotope results recently published by Tedesco et al. [1] appear to show a decrease in 3 He. Results Helium isotope results from our laboratory are reported in Table 1. The 3 He/4 He ratio has been

  3. Isotopic constraints on off-site migration of landfill CH{sub 4}

    SciTech Connect (OSTI)

    Desrocher, S.; Lollar, B.S. [Univ. of Toronto, Ontario (Canada). Dept. of Geology

    1998-09-01T23:59:59.000Z

    Occurrences of CH{sub 4} in residential areas in the vicinity of the Beare Road landfill, Toronto, Canada, have raised public concern about potential off-site migration of CH{sub 4} from the landfill site. Carbon isotopic analysis of dissolved and gas phase CH{sub 4} at the Beare Road site, however, indicates that CH{sub 4} in the ground water systems in the vicinity of the landfill is related to naturally occurring microbial methanogenesis within these geologic units, rather than to contamination by landfill CH{sub 4}. CH{sub 4} gas in the landfill and landfill cover has {delta}{sup 13}C values typical of microbially produced gas. Concentrations of CH{sub 4} found in deep ground water in the Scarborough, Don, and Whitby Formations underlying the landfill are isotopically distinct from the landfill gases. They are isotopically and compositionally similar, however, to naturally occurring microbial CH{sub 4} identified in organic-rich glacial deposits throughout Ontario. The lack of any significant CH{sub 4} concentrations or concentration gradients in the upper tin zone between the landfill and the deep ground water aquifer is further evidence that no transport between the landfill and deep ground water is occurring.

  4. EVIDENCE FOR MAGNESIUM ISOTOPE HETEROGENEITY IN THE SOLAR PROTOPLANETARY DISK

    SciTech Connect (OSTI)

    Larsen, Kirsten K.; Trinquier, Anne; Paton, Chad; Schiller, Martin; Wielandt, Daniel; Connelly, James N.; Nordlund, Ake; Krot, Alexander N.; Bizzarro, Martin [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Copenhagen DK-1350 (Denmark); Ivanova, Marina A. [Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow 119991 (Russian Federation)

    2011-07-10T23:59:59.000Z

    With a half-life of 0.73 Myr, the {sup 26}Al-to-{sup 26}Mg decay system is the most widely used short-lived chronometer for understanding the formation and earliest evolution of the solar protoplanetary disk. However, the validity of {sup 26}Al-{sup 26}Mg ages of meteorites and their components relies on the critical assumption that the canonical {sup 26}Al/{sup 27}Al ratio of {approx}5 x 10{sup -5} recorded by the oldest dated solids, calcium-aluminium-rich inclusions (CAIs), represents the initial abundance of {sup 26}Al for the solar system as a whole. Here, we report high-precision Mg-isotope measurements of inner solar system solids, asteroids, and planets demonstrating the existence of widespread heterogeneity in the mass-independent {sup 26}Mg composition ({mu}{sup 26}Mg*) of bulk solar system reservoirs with solar or near-solar Al/Mg ratios. This variability may represent heterogeneity in the initial abundance of {sup 26}Al across the solar protoplanetary disk at the time of CAI formation and/or Mg-isotope heterogeneity. By comparing the U-Pb and {sup 26}Al-{sup 26}Mg ages of pristine solar system materials, we infer that the bulk of the {mu}{sup 26}Mg* variability reflects heterogeneity in the initial abundance of {sup 26}Al across the solar protoplanetary disk. We conclude that the canonical value of {approx}5 x 10{sup -5} represents the average initial abundance of {sup 26}Al only in the CAI-forming region, and that large-scale heterogeneity-perhaps up to 80% of the canonical value-may have existed throughout the inner solar system. If correct, our interpretation of the Mg-isotope composition of inner solar system objects precludes the use of the {sup 26}Al-{sup 26}Mg system as an accurate early solar system chronometer.

  5. Natural thorium isotopes in marine sediment core off Labuan port

    SciTech Connect (OSTI)

    Hafidz, B. Y.; Asnor, A. S.; Terence, R. C.; Mohamed, C. A. R. [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia 43600, Bangi, Selangor (Malaysia)

    2014-02-12T23:59:59.000Z

    Sediment core was collected from Labuan port and analyzed to determine the radioactivity of thorium (Th) isotopes. The objectives of this study are to determine the possible sources of Th isotopes at Labuan port and estimates the sedimentation rate based on {sup 228}Th/{sup 232}Th model. The results suggest the {sup 230}Th and {sup 232}Th might be originated from terrestrial sedimentary rock while {sup 228}Th originated by authigenic origin. High ratio value of {sup 230}Th/{sup 232}Th detected at the top surface sediment indicates the increasing of {sup 230}Th at the recent years which might be contributed from the anthropogenic sources. The sedimentation rate of core sediment from Labuan Port was successfully estimated by using {sup 228}Th/{sup 232}Th model. The result show high sedimentation rate with 4.67 cm/year indicates rapid deposition occurred at this study area due to the high physical activity at the Labuan port. By assume the constant sedimentation rate at this area; we estimated the age of 142 cm core sediment obtained from Labuan port is 32 years started from 1981 to 2012. This chronology will be used in forthcoming research to investigate the historical profile of anthropogenic activities affecting the Labuan port.

  6. Isotopic measurements of solar noble gases in individual micrometeorites from Greenland and Antarctica

    SciTech Connect (OSTI)

    Olinger, C.T.

    1990-01-01T23:59:59.000Z

    Noble gases are studied in individual 100 micron-size particles selected from Greenland and Antarctic glacial sediments. Noble gas isotopic and elemental patterns confirm the extraterrestrial origin of 81 out of 302 particles studied. Micrometeorites in this size range are particularly interesting because they correspond to the peak of the meteoritic mass flux distribution. Many particles studied are compositionally and morphologically similar to known meteoritic materials.

  7. System size effects and N/Z dependence of balance energy for different isotopic series

    E-Print Network [OSTI]

    Aman D. Sood; Sakshi Gautam

    2011-12-13T23:59:59.000Z

    We study the N/Z dependence of energy of vanishing flow or balance energy for different isotopic series of various system masses like Ca+Ca, Ni+Ni, Zr+Zr, Sn+Sn and Xe+Xe. We find that balance energy decreases with N/Z of the system and follows a linear behaviour. The slope of N/Z dependence is steeper for lighter systems like Ca+Ca and less for heavier ones like Xe+Xe.

  8. Symmetry Energy and the Isoscaling in Reactions on Enriched Tin Isotopes

    E-Print Network [OSTI]

    A. S. Danagulyan; A. R. Balabekyan; G. H. Hovhannisyan

    2009-02-17T23:59:59.000Z

    The coefficients of symmetry energy term for fragments with Z=4,11,12 measured in multifragmentation reactions initiated by proton and deuteron with energy of 3.65A GeV on enriched tin isotopes 112,118,120,124Sn are determined. The dependence of isoscaling parameter on the excitation energy, the temperature of fragmenting systems and the density ratio for heavy mass products are analised.

  9. Degradation of Isotopic Lactate and Acetate

    E-Print Network [OSTI]

    Aronoff, S.

    2010-01-01T23:59:59.000Z

    prescribed, BaC03 from the degradation of Ba acetnte co~~above procedure by the degradation of sjnthetic radio-lacticNo. W-7405-Eng o -48 DEGRADATION OF ISOTOPIC LACTATE AND

  10. Nonequilibrium clumped isotope signals in microbial methane

    E-Print Network [OSTI]

    Wang, David T.

    Methane is a key component in the global carbon cycle with a wide range of anthropogenic and natural sources. Although isotopic compositions of methane have traditionally aided source identification, the abundance of its ...

  11. A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER

    E-Print Network [OSTI]

    O'Donnell, Tom

    A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER FOR PRODUCTION OF NEUTRON-RICH NUCLEI ( 136 Xe Superconducting Cyclotron Laboratory's weekly \\Green Sheet," 30 July 1999 #12; c Thomas W. O'Donnell 2000 All

  12. Carbon isotope fractionation in autotrophic Chromatium

    E-Print Network [OSTI]

    Wong, William Wai-Lun

    1974-01-01T23:59:59.000Z

    CARSON ISOTOPE FRACTIONATION IN AUTOTPOPHIC CHROYATIUN A Thesis 'JILLIAJJ J JAI LJJN BONG Submitted to the Graduate College of Texas A&H University in partial fulfillment of the requirenent for the degree of PLASTER OF SCIENCE August 1974...) August 1974 ABSTRACT Carbon Isotope Fractionation in Autotrophic Chromatium (August 1974) blilliam Wai-Lun Wang, B. S. , Texas Lutheran College Co-Chairmen of Advisory Committee: Dr. Isilliam N. Sackett Dr. Chauncey P. . Benedict Bacterial cells...

  13. Couplings between dipole and quadrupole vibrations in tin isotopes

    E-Print Network [OSTI]

    Cédric Simenel; Philippe Chomaz

    2009-12-11T23:59:59.000Z

    We study the couplings between collective vibrations such as the isovector giant dipole and isoscalar giant quadrupole resonances in tin isotopes in the framework of the time-dependent Hartree-Fock theory with a Skyrme energy density functional. These couplings are a source of anharmonicity in the multiphonon spectrum. In particular, the residual interaction is known to couple the isovector giant dipole resonance with the isoscalar giant quadrupole resonance built on top of it, inducing a nonlinear evolution of the quadrupole moment after a dipole boost. This coupling also affects the dipole motion in a nucleus with a static or dynamical deformation induced by a quadrupole constraint or boost respectively. Three methods associated with these different manifestations of the coupling are proposed to extract the corresponding matrix elements of the residual interaction. Numerical applications of the different methods to 132Sn are in good agreement with each other. Finally, several tin isotopes are considered to investigate the role of isospin and mass number on this coupling. A simple 1/A dependence of the residual matrix elements is found with no noticeable contribution from the isospin. This result is interpreted within the Goldhaber-Teller model.

  14. Ion desolvation as a mechanism for kinetic isotope fractionation in aqueous systems

    E-Print Network [OSTI]

    Hofmann, A.E.

    2014-01-01T23:59:59.000Z

    equilibrium light?isotope  enrichment is a key unknown in of light?isotope  enrichment  during  precipitation.  possible light? isotope enrichment from diffusion?limited 

  15. NATIONAL USES AND NEEDS FOR SEPARATED STABLE ISOTOPES IN PHYSICS, CHEMISTRY, AND GEOSCIENCE RESEARCH

    E-Print Network [OSTI]

    Zisman, M.S.

    2010-01-01T23:59:59.000Z

    of purchasing a low-enrichment isotope and having it furtherfour main areas: of isotopes, marginal enrichment and a highthe allowing isotope much interest enrichment into play, in

  16. Oxygen isotope fractionation in the vacuum ultraviolet photodissociation of carbon monoxide: Wavelength, pressure and temperature dependency.

    E-Print Network [OSTI]

    Chakraborty, Subrata

    2013-01-01T23:59:59.000Z

    Oxygen isotope fractionation in the vacuum ultravioletmeasurement of the associated oxygen isotopic composition ofwavelength dependency of the oxygen isotopic composition in

  17. Direct mass measurements beyond the proton drip-line

    E-Print Network [OSTI]

    C. Rauth; D. Ackermann; K. Blaum; M. Block; A. Chaudhuri; S. Eliseev; R. Ferrer; D. Habs; F. Herfurth; F. P. Hessberger; S. Hofmann; H. -J. Kluge; G. Maero; A. Martin; G. Marx; M. Mukherjee; J. B. Neumayr; W. R. Plass; W. Quint; S. Rahaman; D. Rodriguez; C. Scheidenberger; L. Schweikhard; P. G. Thirolf; G. Vorobjev; C. Weber; Z. Di

    2007-01-22T23:59:59.000Z

    First on-line mass measurements were performed at the SHIPTRAP Penning trap mass spectrometer. The masses of 18 neutron-deficient isotopes in the terbium-to-thulium region produced in fusion-evaporation reactions were determined with relative uncertainties of about $7\\cdot 10^{-8}$, nine of them for the first time. Four nuclides ($^{144, 145}$Ho and $^{147, 148}$Tm) were found to be proton-unbound. The implication of the results on the location of the proton drip-line is discussed by analyzing the one-proton separation energies.

  18. Influence of liquid structure on diffusive isotope separation in molten silicates and aqueous solutions

    SciTech Connect (OSTI)

    Watkins, J.M.; DePaolo, D.J.; Ryerson, F.J.; Peterson, B.

    2011-03-01T23:59:59.000Z

    Molecular diffusion in natural volcanic liquids discriminates between isotopes of major ions (e.g., Fe, Mg, Ca, and Li). Although isotope separation by diffusion is expected on theoretical grounds, the dependence on mass is highly variable for different elements and in different media. Silicate liquid diffusion experiments using simple liquid compositions were carried out to further probe the compositional dependence of diffusive isotopic discrimination and its relationship to liquid structure. Two diffusion couples consisting of the mineral constituents anorthite (CaAl{sub 2}Si{sub 2}O{sub 8}; denoted AN), albite (NaAlSi{sub 3}O{sub 8}; denoted AB), and diopside (CaMgSi{sub 2}O{sub 6}; denoted DI) were held at 1450°C for 2 h and then quenched to ambient pressure and temperature. Major-element as well as Ca and Mg isotope profiles were measured on the recovered quenched glasses. In both experiments, Ca diffuses rapidly with respect to Si. In the AB–AN experiment, D{sub Ca}/D{sub Si} ~ 20 and the efficiency of isotope separation for Ca is much greater than in natural liquid experiments where D{sub Ca}/D{sub Si} ~ 1. In the AB–DI experiment, D{sub Ca}/D{sub Si} ~ 6 and the efficiency of isotope separation is between that of the natural liquid experiments and the AB–AN experiment. In the AB–DI experiment, D{sub Mg}/D{sub Si} ~ 1 and the efficiency of isotope separation for Mg is smaller than it is for Ca yet similar to that observed for Mg in natural liquids. The results from the experiments reported here, in combination with results from natural volcanic liquids, show clearly that the efficiency of diffusive separation of Ca isotopes is systematically related to the solvent-normalized diffusivity—the ratio of the diffusivity of the cation (D{sub Ca}) to the diffusivity of silicon (D{sub Si}). The results on Ca isotopes are consistent with available data on Fe, Li, and Mg isotopes in silicate liquids, when considered in terms of the parameter D{sub cation}/D{sub Si}. Cations diffusing in aqueous solutions display a similar relationship between isotopic separation efficiency and D{sub cation} =D{sub H 2 O} , although the efficiencies are smaller than in silicate liquids. Our empirical relationship provides a tool for predicting the magnitude of diffusive isotopic effects in many geologic environments and a basis for a more comprehensive theory of isotope separation in liquid solutions. We present a conceptual model for the relationship between diffusivity and liquid structure that is consistent with available data.

  19. - and -delayed neutron- decay of neutron-rich copper isotopes

    SciTech Connect (OSTI)

    Korgul, A. [University of Warsaw; Rykaczewski, Krzysztof Piotr [ORNL; Winger, J. A. [Oak Ridge Associated Universities (ORAU); Ilyushkin, S. [Mississippi State University (MSU); Gross, Carl J [ORNL; Batchelder, J. C. [Oak Ridge Associated Universities (ORAU); Bingham, C. R. [University of Tennessee, Knoxville (UTK); Borzov, Ivan N [ORNL; Goodin, C. [Vanderbilt University; Grzywacz, Robert Kazimierz [ORNL; Hamilton, Joseph H [ORNL; Krolas, W. [Joint Institute for Heavy Ion Research, Oak Ridge; Liddick, S. N. [Oak Ridge Associated Universities (ORAU); Mazzocchi, C. [University of Warsaw; Nelson, C. [Vanderbilt University; Nowacki, F. [Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Padgett, Stephen [University of Tennessee, Knoxville (UTK); Piechaczek, A. [Louisiana State University; Rajabali, M. M. [University of Tennessee, Knoxville (UTK); Shapira, Dan [ORNL; Sieja, K. [Technische Universitat Darmstadt, Germany; Zganjar, E. F. [Louisiana State University

    2012-01-01T23:59:59.000Z

    The {beta}-decay properties of neutron-rich Cu isotopes produced in proton-induced fission of {sup 238}U were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The data were collected using high-resolution online mass separation, reacceleration, and digital {beta}-{gamma} spectroscopy methods. An improved decay scheme of N = 49 {sup 78}Cu and the first observation of N = 50 {sup 79}Cu {beta}-delayed neutron decay followed by a gamma transition are reported. Spin and parity (5{sup -}) are deduced for {sup 78gs}Cu. The {beta}-delayed neutron branching ratios (P{sub {beta}n}) for the {sup 77}Cu and {sup 79}Cu precursors are analyzed with the help of nuclear structure models.

  20. Exotic fission properties of highly neutron-rich Uranium isotopes

    E-Print Network [OSTI]

    L. Satpathy; S. K. Patra; R. K. Choudhury

    2007-03-05T23:59:59.000Z

    The series of Uranium isotopes with $N=154 \\sim 172$ around the magic number N=162/164 are identified to be thermally fissile. The thermal neutron fission of a typical representative $^{249}$U of this region amenable to synthesis in the radioactive ion beam facilities is considered here. Semiempirical study of fission barrier height and width shows this nucleus to be infinitely stable against spontaneous fission due to increase in barrier width arising out of excess neutrons. Calculation of probability of fragment mass yields and microscopic study in relativistic mean field theory, show this nucleus to undergo a new mode of thermal fission decay termed {\\it multifragmentation fission} where a number of prompt scission neutrons are simultaneously released along with the two heavy fission fragments.

  1. Proton elastic scattering from tin isotopes at 295 MeV and systematic change of neutron density distributions

    E-Print Network [OSTI]

    S. Terashima; H. Sakaguchi; H. Takeda; T. Ishikawa; M. Itoh; T. Kawabata; T. Murakami; M. Uchida; Y. Yasuda; M. Yosoi; J. Zenihiro; H. P. Yoshida; T. Noro; T. Ishida; S. Asaji; T. Yonemura

    2008-02-02T23:59:59.000Z

    Cross sections and analyzing powers for proton elastic scattering from $^{116,118,120,122,124}$Sn at 295 MeV have been measured for a momentum transfer of up to about 3.5 fm$^{-1}$ to deduce systematic changes of the neutron density distribution. We tuned the relativistic Love-Franey interaction to explain the proton elastic scattering of a nucleus whose density distribution is well known. Then, we applied this interaction to deduce the neutron density distributions of tin isotopes. The result of our analysis shows the clear systematic behavior of a gradual increase in the neutron skin thickness of tin isotopes with mass number.

  2. MIXING AND TRANSPORT OF SHORT-LIVED AND STABLE ISOTOPES AND REFRACTORY GRAINS IN PROTOPLANETARY DISKS

    SciTech Connect (OSTI)

    Boss, Alan P., E-mail: boss@dtm.ciw.edu [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road, NW, Washington, DC 20015-1305 (United States)

    2013-08-10T23:59:59.000Z

    Analyses of primitive meteorites and cometary samples have shown that the solar nebula must have experienced a phase of large-scale outward transport of small refractory grains as well as homogenization of initially spatially heterogeneous short-lived isotopes. The stable oxygen isotopes, however, were able to remain spatially heterogeneous at the {approx}6% level. One promising mechanism for achieving these disparate goals is the mixing and transport associated with a marginally gravitationally unstable (MGU) disk, a likely cause of FU Orionis events in young low-mass stars. Several new sets of MGU models are presented that explore mixing and transport in disks with varied masses (0.016 to 0.13 M{sub Sun }) around stars with varied masses (0.1 to 1 M{sub Sun }) and varied initial Q stability minima (1.8 to 3.1). The results show that MGU disks are able to rapidly (within {approx}10{sup 4} yr) achieve large-scale transport and homogenization of initially spatially heterogeneous distributions of disk grains or gas. In addition, the models show that while single-shot injection heterogeneity is reduced to a relatively low level ({approx}1%), as required for early solar system chronometry, continuous injection of the sort associated with the generation of stable oxygen isotope fractionations by UV photolysis leads to a sustained, relatively high level ({approx}10%) of heterogeneity, in agreement with the oxygen isotope data. These models support the suggestion that the protosun may have experienced at least one FU Orionis-like outburst, which produced several of the signatures left behind in primitive chondrites and comets.

  3. Nuclear Moments and Differences in Mean Square Charge Radii of Short-Lived Neon Isotopes by Collinear Laser Spectroscopy

    E-Print Network [OSTI]

    Geithner, R W

    2002-01-01T23:59:59.000Z

    The nuclear moments and charge radii of short-lived neon isotopes were measured by the use of collinear laser spectroscopy at the on-line mass separator ISOLDE at CERN. After a general introduction the semiclassical theory of atomic spectra is given and the relevant properties are calculated for neon. The atomic physics section is followed by a description of the experimental setup of the collinear laser spectroscopy experiment at ISOLDE. From the mass separator an isotopically clean ion beam with a kinetic energy of 60 keV is delivered to the experiments. In collinear laser spectroscopy the incoming ion beam from the mass separator is superimposed to a single frequency cw laser beam. The frequency of the atomic transition $\

  4. Searching for isovector signatures in the neutron-rich oxygen and calcium isotopes

    E-Print Network [OSTI]

    Wei-Chia Chen; J. Piekarewicz

    2015-03-10T23:59:59.000Z

    We search for potential isovector signatures in the neutron-rich oxygen and calcium isotopes within the framework of a relativistic mean-field theory with an exact treatment of pairing correlations. To probe the isovector sector we calibrate a few relativistic density functionals using the same isoscalar constraints but with one differing isovector assumption. It is found that under certain conditions, the isotopic chain in oxygen can be made to terminate at the experimentally observed ${}^{24}$O isotope and in the case of the calcium isotopes at ${}^{60}$Ca. To produce such behavior, the resulting symmetry energy must be soft, with predicted values for the symmetry energy and its slope at saturation density being $J\\!=\\!(30.92\\pm0.47)$ MeV and $L\\!=\\!(51.0\\pm1.5)$ MeV, respectively. As a consequence, the neutron-skin thickness of ${}^{208}$Pb is rather small: $R_{\\rm skin}^{208}\\!=\\!(0.161\\pm0.011)$ fm. This same model - labelled "FSUGarnet" - predicts $R_{1.4}\\!=\\!(13.1\\pm0.1)$ km for the radius of a "canonical" 1.4$M_{\\odot}$ neutron star, yet is also able to support a two-solar-mass neutron star.

  5. Design, construction, and operation of a laboratory scale reactor for the production of high-purity, isotopically enriched bulk silicon

    E-Print Network [OSTI]

    Ager III, J.W.; Beeman, J.W.; Hansen, W.L.; Haller, E.E.

    2004-01-01T23:59:59.000Z

    Russia. The stated isotope enrichments are summarized inenrichments >99% have been achieved for each isotope and

  6. Compositional Analysis of the High Molecular Weight Ethylene Oxide Propylene Oxide Copolymer by MALDI Mass Spectrometry

    E-Print Network [OSTI]

    Houshia, Orwa Jaber

    2012-01-01T23:59:59.000Z

    The composition of narrow distribution poly ethylene oxide-propylene oxide copolymer (Mw ~ 8700 Da) was studied using matrix assisted laser desorption ionization (MALDI) mass spectrometry. The ethylene oxide-propylene oxide copolymer produced oligomers separated by 14 Da. The average resolving power over the entire spectrum was 28,000. Approximately 448 isotopically resolved peaks representing about 56 oligomers are identified. Although agreement between experimental and calculated isotopic distributions was strong, the compositional assignment was difficult. This is due to the large number of possible isobaric components. The purpose of this research is to resolve and study the composition of high mass copolymer such as ethylene oxide-propylene oxide.

  7. Atomic line emission analyzer for hydrogen isotopes

    DOE Patents [OSTI]

    Kronberg, J.W.

    1991-05-08T23:59:59.000Z

    Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the emission of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the lines of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using, a metal hydride.

  8. Atomic line emission analyzer for hydrogen isotopes

    DOE Patents [OSTI]

    Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

    1993-01-01T23:59:59.000Z

    Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the emission of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the lines of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using a metal hydride.

  9. Apparatus for separating and recovering hydrogen isotopes

    DOE Patents [OSTI]

    Heung, Leung K. (Aiken, SC)

    1994-01-01T23:59:59.000Z

    An apparatus for recovering hydrogen and separating its isotopes. The apparatus includes a housing bearing at least a fluid inlet and a fluid outlet. A baffle is disposed within the housing, attached thereto by a bracket. A hollow conduit is coiled about the baffle, in spaced relation to the baffle and the housing. The coiled conduit is at least partially filled with a hydride. The hydride can be heated to a high temperature and cooled to a low temperature quickly by circulating a heat transfer fluid in the housing. The spacing between the baffle and the housing maximizes the heat exchange rate between the fluid in the housing and the hydride in the conduit. The apparatus can be used to recover hydrogen isotopes (protium, deuterium and tritium) from gaseous mixtures, or to separate hydrogen isotopes from each other.

  10. Atomic line emission analyzer for hydrogen isotopes

    DOE Patents [OSTI]

    Kronberg, J.W.

    1993-03-30T23:59:59.000Z

    Apparatus for isotopic analysis of hydrogen comprises a low pressure chamber into which a sample of hydrogen is introduced and then exposed to an electrical discharge to excite the electrons of the hydrogen atoms to higher energy states and thereby cause the emission of light on the return to lower energy states, a Fresnel prism made at least in part of a material anomalously dispersive to the wavelengths of interest for dispersing the emitted light, and a photodiode array for receiving the dispersed light. The light emitted by the sample is filtered to pass only the desired wavelengths, such as one of the lines of the Balmer series for hydrogen, the wavelengths of which differ slightly from one isotope to another. The output of the photodiode array is processed to determine the relative amounts of each isotope present in the sample. Additionally, the sample itself may be recovered using a metal hydride.

  11. Isotope effects in methanol synthesis and the reactivity of copper...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Isotope effects in methanol synthesis and the reactivity of copper formates on a CuSiO2 catalyst. Isotope effects in methanol synthesis and the reactivity of copper formates on a...

  12. Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui

    E-Print Network [OSTI]

    Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui Sitindra S studied the controls on the fractionation of hydrogen isotopes during lipid biosynthesis by Haloarcula marismortui, a halophilic archaea, in pure culture experiments by varying organic substrate, the hydrogen

  13. Oxygen isotope records of carboniferous seasonality on the Russian platform

    E-Print Network [OSTI]

    Wang, Huayu

    1998-01-01T23:59:59.000Z

    Seven isotopic and eight trace element (TE) profiles across shell growth lines are presented, based on over 1000 stable isotope and electron microprobe analyses on six brachiopod shells (Gigantoproductus), to quantify seasonal temperature change...

  14. Physiology of multiple sulfur isotope fractionation during microbial sulfate reduction

    E-Print Network [OSTI]

    Sim, Min Sub

    2012-01-01T23:59:59.000Z

    Microbial sulfate reduction (MSR) utilizes sulfate as an electron acceptor and produces sulfide that is depleted in heavy isotopes of sulfur relative to starting sulfate. The fractionation of S-isotopes is commonly used ...

  15. Delayed neutron measurements from fast fission of actinide waste isotopes

    E-Print Network [OSTI]

    Charlton, William S.

    1997-01-01T23:59:59.000Z

    A study was performed to determine the delayed neutron emission properties from fast fission of several actinide waste isotopes. The specific isotopes evaluated were U-235, Np-237, and Am-243. A calculational technique based on the microscopic...

  16. High Flux Isotope Reactor named Nuclear Historic Landmark | ornl...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    High Flux Isotope Reactor named Nuclear Historic Landmark The High Flux Isotope Reactor vessel at Oak Ridge National Laboratory resides in a pool of water illuminated by the blue...

  17. First Results from the CARIBU Facility: Mass Measurements on the r-Process Path

    E-Print Network [OSTI]

    J. Van Schelt; D. Lascar; G. Savard; J. A. Clark; P. F. Bertone; S. Caldwell; A. Chaudhuri; 1 A. F. Levand; G. Li; G. E. Morgan; R. Orford; R. E. Segel; K. S. Sharma; M. G. Sternberg

    2013-07-01T23:59:59.000Z

    The Canadian Penning Trap mass spectrometer has made mass measurements of 33 neutron-rich nuclides provided by the new Californium Rare Isotope Breeder Upgrade (CARIBU) facility at Argonne National Laboratory. The studied region includes the 132Sn double shell closure and ranges in Z from In to Cs, with Sn isotopes measured out to A = 135, and the typical measurement precision is at the 100 ppb level or better. The region encompasses a possible major waiting point of the astrophysical r process, and the impact of the masses on the r process is shown through a series of simulations. These first-ever simulations with direct mass information on this waiting point show significant increases in waiting time at Sn and Sb in comparison with commonly used mass models, demonstrating the inadequacy of existing models for accurate r-process calculations.

  18. Ultra-low Q values for neutrino mass measurements

    E-Print Network [OSTI]

    Joachim Kopp; Alexander Merle

    2010-04-21T23:59:59.000Z

    We investigate weak nuclear decays with extremely small kinetic energy release (Q value) and thus extremely good sensitivity to the absolute neutrino mass scale. In particular, we consider decays into excited daughter states, and we show that partial ionization of the parent atom can help to tune Q values to low-Q decays might only be feasible if no ionization is required, and if future improvements in isotope production technology, nuclear mass spectroscopy, and atomic structure calculations are possible. Experiments using ions, however, are extremely challenging due to the large number of ions that must be stored. New precision data on nuclear excitation levels could help to identify further isotopes with low-Q decay modes and possibly less challenging requirements.

  19. Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal...

    Open Energy Info (EERE)

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal Area (Phillips, 2004)...

  20. Isotopic Analysis At Lassen Volcanic National Park Area (Janik...

    Open Energy Info (EERE)

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis At Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Exploration Activity...

  1. Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal...

    Open Energy Info (EERE)

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Geothermal Area (Ito & Tanaka, 1995)...

  2. Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Area...

    Open Energy Info (EERE)

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Rock At Valles Caldera - Sulphur Springs Area (Ito & Tanaka, 1995) Exploration...

  3. Isotopic Analysis At Valles Caldera - Redondo Geothermal Area...

    Open Energy Info (EERE)

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis At Valles Caldera - Redondo Geothermal Area (Phillips, 2004) Exploration Activity...

  4. Stable carbon and nitrogen isotope enrichment in primate tissues

    E-Print Network [OSTI]

    Crowley, Brooke E.; Carter, Melinda L.; Karpanty, Sarah M.; Zihlman, Adrienne L.; Koch, Paul L.; Dominy, Nathaniel J.

    2010-01-01T23:59:59.000Z

    of sample treatment and diagenesis on the isotopic integrityHare PE (1986) Effects of diagenesis on strontium, carbon,

  5. Isotopic abundance in atom trap trace analysis

    DOE Patents [OSTI]

    Lu, Zheng-Tian; Hu, Shiu-Ming; Jiang, Wei; Mueller, Peter

    2014-03-18T23:59:59.000Z

    A method and system for detecting ratios and amounts of isotopes of noble gases. The method and system is constructed to be able to measure noble gas isotopes in water and ice, which helps reveal the geological age of the samples and understand their movements. The method and system uses a combination of a cooled discharge source, a beam collimator, a beam slower and magneto-optic trap with a laser to apply resonance frequency energy to the noble gas to be quenched and detected.

  6. Isotope Research Materials Laboratory | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer ReviewIron isIsIsotope ProgramIsotope

  7. Augmenting real data with synthetic data: an application in assessing radio-isotope identification algorithms

    SciTech Connect (OSTI)

    Burr, Tom L [Los Alamos National Laboratory; Hamada, Michael [Los Alamos National Laboratory; Graves, Todd [Los Alamos National Laboratory; Myers, Steve [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    The performance of Radio-Isotope Identification (RIID) algorithms using gamma spectroscopy is increasingly important. For example, sensors at locations that screen for illicit nuclear material rely on isotope identification to resolve innocent nuisance alarms arising from naturally occurring radioactive material. Recent data collections for RIID testing consist of repeat measurements for each of several scenarios to test RIID algorithms. Efficient allocation of measurement resources requires an appropriate number of repeats for each scenario. To help allocate measurement resources in such data collections for RIID algorithm testing, we consider using only a few real repeats per scenario. In order to reduce uncertainty in the estimated RIID algorithm performance for each scenario, the potential merit of augmenting these real repeats with realistic synthetic repeats is also considered. Our results suggest that for the scenarios and algorithms considered, approximately 10 real repeats augmented with simulated repeats will result in an estimate having comparable uncertainty to the estimate based on using 60 real repeats.

  8. Isotope effect evidence for the zinc hydroxide mechanism of carbonic anhydrase catalyst

    SciTech Connect (OSTI)

    Paneth, P.; O'Leary, M.H.

    1987-03-24T23:59:59.000Z

    The carbon kinetic isotope effect on the enzymatic dehydration of HCO/sub 3//sup -/ ion is k/sup 12//k/sup 13/ = 1.011 and is independent, within experimental error, of the addition of sucrose, substitution of D/sub 2/O for H/sub 2/O, and substitution of enzyme-bound Zn/sup 2 +/ by Co/sup 2 +/. These results are consistent with a ping-pong mechanism in which proton transfer between enzyme and solvent is separated from HCO/sub 3//sup -/ dehydration. For the dehydration half-reaction, diffusional processes are severalfold faster than dehydration, and the rate-determining step is the dehydration itself. The intrinsic isotope effect is approximately 1.011, indicating that hydration of CO/sub 2/ occurs by reaction of zinc-bound OH/sup -/, rather than zinc-bound H/sub 2/O.

  9. Isotope effect evidence for the zinc hydroxide mechanism of carbonic anhydrase catalysis

    SciTech Connect (OSTI)

    Paneth, P.; O'Leary, M.H.

    1987-03-24T23:59:59.000Z

    The carbon kinetic isotope effect on the enzymatic dehydration of HCO/sub 3/- ion is k12/k13 = 1.011 and is independent, within experimental error, of the addition of sucrose, substitution of D/sub 2/O for H/sub 2/O, and substitution of enzyme-bound Zn/sup 2 +/ by Co/sup 2 +/. These results are consistent with a ping-pong mechanism in which proton transfer between enzyme and solvent is separated from HCO/sub 3/- dehydration. For the dehydration half-reaction, diffusional processes are severalfold faster than dehydration, and the rate-determining step is the dehydration itself. The intrinsic isotope effect is approximately 1.011, indicating that hydration of CO/sub 2/ occurs by reaction of zinc-bound OH-, rather than zinc-bound H/sub 2/O.

  10. Naturally occurring hydrogen gas from a borehole on the western flank of Nemaha anticline in Kansas

    SciTech Connect (OSTI)

    Goebel, E.D.; Coveney, R.M. Jr.; Angino, E.E.; Zeller, E.

    1983-08-01T23:59:59.000Z

    Since August 1982, the CFA 1 Scott well in Sec. 20, T14S, R6E, Morris County, Kansas, located about 14 mi (23 km) south of Junction City, has yielded a gas composed of 50 +/- 10% free hydrogen, 50 +/- 10% nitrogen, and only traces of hydrocarbons. This analysis has been ascertained by gas chromatography and mass spectrography of samples taken over a period of 6 months. The reservoir rock is a Kinderhook sand from 2176 to 2196 ft (663 to 669m) depth. The gas samples analyzed are accumulating in the head space above a fluid level (salt water) of 1805 ft (550m) from a botton-hole depth of 2197 ft (670m). The Scott well is located on the western flank of the complexly faulted Nemaha anticline, updip from the central North American rift system and 30 mi (48 km) south of Riley County where serpentinized kimberlites occur. The geothermal gradient is 30/sup 0/C/km (87/sup 0/F/mi). Basement rock beneath the well is granite, probably overlying deeply buried magnetic rocks. No single mechanism is responsible solely for generating this H/sub 2/-rich gas from the Scott well; rather, a combination of fortuitous geologic and possibly biologic processes are contributing in various proportions to the production of the H/sub 2/ and N/sub 2/. Conceivably, the local geologic setting merely is circumstantial and unrelated to the genesis of the gases. However, in view of its spatial association with the central North American rift Zone, a major geologic feature with similarity to the East Pacific Rise, the Kansas gas occurrence warrants additional study.

  11. Hydrogen isotope fractionation during lipid biosynthesis by Tetrahymena thermophila

    E-Print Network [OSTI]

    Hydrogen isotope fractionation during lipid biosynthesis by Tetrahymena thermophila Sitindra S Accepted 7 September 2013 Available online 16 September 2013 a b s t r a c t Hydrogen isotope ratio values from recording the hydrogen isotope composition of ambient water, dD values of lipids also depend

  12. ORIGINAL RESEARCH Hydrogen and carbon isotope fractionation during

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , enrichment in 13 C of untransformed CH3Cl was also observed, and similar isotope enrichment factors (e) of ÀORIGINAL RESEARCH Hydrogen and carbon isotope fractionation during degradation of chloromethane-Meitner-Weg 1, 55128 Mainz, Germany Keywords Carbon isotope fractionation, chloromethane biodegradation

  13. Research Article Peculiarities in the stable isotope composition of organisms

    E-Print Network [OSTI]

    Rasmussen, Joseph

    that dietary N content can affect trophic level 15 N enrichment. The anomalies in stable isotope concen; dietary N; 15 N enrichment. Introduction Over the last decade, stable isotopes have been used inResearch Article Peculiarities in the stable isotope composition of organisms from an alpine lake

  14. Discovery of the actinium, thorium, protactinium, and uranium isotopes

    E-Print Network [OSTI]

    C. Fry; M. Thoennessen

    2012-03-06T23:59:59.000Z

    Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  15. Discovery of dysprosium, holmium, erbium, thulium, and ytterbium isotopes

    SciTech Connect (OSTI)

    Fry, C.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

    2013-09-15T23:59:59.000Z

    Currently, thirty-one dysprosium, thirty-two holmium, thirty-two erbium, thirty-three thulium, and thirty-one ytterbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  16. Discovery of palladium, antimony, tellurium, iodine, and xenon isotopes

    SciTech Connect (OSTI)

    Kathawa, J.; Fry, C.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

    2013-01-15T23:59:59.000Z

    Currently, thirty-eight palladium, thirty-eight antimony, thirty-nine tellurium, thirty-eight iodine, and forty xenon isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  17. Discovery of the astatine, radon, francium, and radium isotopes

    SciTech Connect (OSTI)

    Fry, C.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

    2013-09-15T23:59:59.000Z

    Thirty-nine astatine, thirty-nine radon, thirty-five francium, and thirty-four radium isotopes have so far been observed; the discovery of these isotopes is described. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  18. Discovery of samarium, europium, gadolinium, and terbium isotopes

    SciTech Connect (OSTI)

    May, E.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

    2013-01-15T23:59:59.000Z

    Currently, thirty-four samarium, thirty-four europium, thirty-one gadolinium, and thirty-one terbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  19. Discovery of Yttrium, Zirconium, Niobium, Technetium, and Ruthenium Isotopes

    E-Print Network [OSTI]

    A. Nystrom; M. Thoennessen

    2011-02-11T23:59:59.000Z

    Currently, thirty-four yttrium, thirty-five zirconium, thirty-four niobium, thirty-five technetium, and thirty-eight ruthenium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  20. Discovery of Yttrium, Zirconium, Niobium, Technetium, and Ruthenium Isotopes

    E-Print Network [OSTI]

    Nystrom, A

    2011-01-01T23:59:59.000Z

    Currently, thirty-four yttrium, thirty-five zirconium, thirty-four niobium, thirty-five technetium, and thirty-eight ruthenium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  1. Discovery of Scandium, Titanium, Mercury, and Einsteinium Isotopes

    E-Print Network [OSTI]

    D. Meierfrankenfeld; A. Bury; M. Thoennessen

    2010-09-08T23:59:59.000Z

    Currently, twenty-three scandium, twenty-five titanium, forty mercury and seventeen einsteinium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  2. Discovery of Samarium, Europium, Gadolinium, and Terbium Isotopes

    E-Print Network [OSTI]

    E. May; M. Thoennessen

    2012-01-19T23:59:59.000Z

    Currently, thirty-four samarium, thirty-four europium, thirty-one gadolinium, and thirty-one terbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  3. Discovery of Samarium, Europium, Gadolinium, and Terbium Isotopes

    E-Print Network [OSTI]

    May, E

    2012-01-01T23:59:59.000Z

    Currently, thirty-four samarium, thirty-four europium, thirty-one gadolinium, and thirty-one terbium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  4. Isotope effect in the photochemical decomposition of CO{sub 2} (ice) by Lyman-{alpha} radiation

    SciTech Connect (OSTI)

    Yuan Chunqing; Yates, John T. Jr. [Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904 (United States)

    2013-04-21T23:59:59.000Z

    The photochemical decomposition of CO{sub 2}(ice) at 75 K by Lyman-{alpha} radiation (10.2 eV) has been studied using transmission infrared spectroscopy. An isotope effect in the decomposition of the CO{sub 2} molecule in the ice has been discovered, favoring {sup 12}CO{sub 2} photodecomposition over {sup 13}CO{sub 2} by about 10%. The effect is caused by electronic energy transfer from the excited CO{sub 2} molecule to the ice matrix, which favors quenching of the heavier electronically-excited {sup 13}CO{sub 2} molecule over {sup 12}CO{sub 2}. The effect is similar to the Menzel-Gomer-Redhead isotope effect in desorption from adsorbed molecules on surfaces when electronically excited. An enhancement of the rate of formation of lattice-trapped CO and CO{sub 3} species is observed for the photolysis of the {sup 12}CO{sub 2} molecule compared to the {sup 13}CO{sub 2} molecule in the ice. Only 0.5% of the primary photoexcitation results in O-CO bond dissociation to produce trapped-CO and trapped-CO{sub 3} product molecules and the majority of the electronically-excited CO{sub 2} molecules return to the ground state. Here either vibrational relaxation occurs (majority process) or desorption of CO{sub 2} occurs (minority process) from highly vibrationally-excited CO{sub 2} molecules in the ice. The observation of the {sup 12}C/{sup 13}C isotope effect in the Lyman-{alpha} induced photodecomposition of CO{sub 2} (ice) suggests that over astronomical time scales the isotope enrichment effect may distort historical information derived from isotope ratios in space wherever photochemistry can occur.

  5. Neutrino mass matrix

    SciTech Connect (OSTI)

    Strobel, E.L.

    1985-01-01T23:59:59.000Z

    Given the many conflicting experimental results, examination is made of the neutrino mass matrix in order to determine possible masses and mixings. It is assumed that the Dirac mass matrix for the electron, muon, and tau neutrinos is similar in form to those of the quarks and charged leptons, and that the smallness of the observed neutrino masses results from the Gell-Mann-Ramond-Slansky mechanism. Analysis of masses and mixings for the neutrinos is performed using general structures for the Majorana mass matrix. It is shown that if certain tentative experimental results concerning the neutrino masses and mixing angles are confirmed, significant limitations may be placed on the Majorana mass matrix. The most satisfactory simple assumption concerning the Majorana mass matrix is that it is approximately proportional to the Dirac mass matrix. A very recent experimental neutrino mass result and its implications are discussed. Some general properties of matrices with structure similar to the Dirac mass matrices are discussed.

  6. Laser Isotope Enrichment for Medical and Industrial Applications

    SciTech Connect (OSTI)

    Leonard Bond

    2006-07-01T23:59:59.000Z

    Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: 1) Pure isotopic targets for irradiation to produce medical radioisotopes. 2) Pure isotopes for semiconductors. 3) Low neutron capture isotopes for various uses in nuclear reactors. 4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ”calutrons” (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation repression. In this scheme a gas, of the selected isotopes for enrichment, is irradiated with a laser at a particular wavelength that would excite only one of the isotopes. The entire gas is subject to low temperatures sufficient to cause condensation on a cold surface. Those molecules in the gas that the laser excited are not as likely to condense as are the unexcited molecules. Hence the gas drawn out of the system will be enriched in the isotope that was excited by the laser. We have evaluated the relative energy required in this process if applied on a commercial scale. We estimate the energy required for laser isotope enrichment is about 20% of that required in centrifuge separations, and 2% of that required by use of "calutrons".

  7. Ultra High Mass Range Mass Spectrometer System

    DOE Patents [OSTI]

    Reilly, Peter T. A. [Knoxville, TN

    2005-12-06T23:59:59.000Z

    Applicant's present invention comprises mass spectrometer systems that operate in a mass range from 1 to 10.sup.16 DA. The mass spectrometer system comprising an inlet system comprising an aerodynamic lens system, a reverse jet being a gas flux generated in an annulus moving in a reverse direction and a multipole ion guide; a digital ion trap; and a thermal vaporization/ionization detector system. Applicant's present invention further comprises a quadrupole mass spectrometer system comprising an inlet system having a quadrupole mass filter and a thermal vaporization/ionization detector system. Applicant's present invention further comprises an inlet system for use with a mass spectrometer system, a method for slowing energetic particles using an inlet system. Applicant's present invention also comprises a detector device and a method for detecting high mass charged particles.

  8. Effective Mass and Energy-Mass Relationship

    E-Print Network [OSTI]

    Viktor Ariel

    2012-05-14T23:59:59.000Z

    The particle effective mass is often a challenging concept in solid state physics due to the many different definitions of the effective mass that are routinely used. Also, the most commonly used theoretical definition of the effective mass was derived from the assumption of a parabolic energy-momentum relationship, E(p), and therefore should not be applied to non-parabolic materials. In this paper, we use wave-particle duality to derive a definition of the effective mass and the energy-mass approximation suitable for non-parabolic materials. The new energy-mass relationship can be considered a generalization of Einstein's E=mc^2 suitable for arbitrary E(p) and therefore applicable to solid state materials and devices. We show that the resulting definition of the effective mass seems suitable for non-paraboic solid state materials such as HgCdTe, GaAs, and graphene.

  9. A review of stable water isotopeA review of stable water isotope modellingmodelling

    E-Print Network [OSTI]

    Sturm, Christophe "Kristof"

    fractionation · Kinetic fractionation 2. Modelling the stable water isotope cycle · Rayleigh distillation model Institution of Oceanography) Harald SODEMANN (Norwegian Institute for Air Research) Kristof 18Ovapour=-40 18Oocean=0 18Osnow=-3018Orain=-2 Equilibrium fractionationEquilibrium fractionation

  10. Review of hydrogen isotope permeability through materials

    SciTech Connect (OSTI)

    Steward, S.A.

    1983-08-15T23:59:59.000Z

    This report is the first part of a comprehensive summary of the literature on hydrogen isotope permeability through materials that do not readily form hydrides. While we mainly focus on pure metals with low permeabilities because of their importance to tritium containment, we also give data on higher-permeability materials such as iron, nickel, steels, and glasses.

  11. Trace Element and Isotopic Fluxes/ Subducted Slab

    E-Print Network [OSTI]

    Bebout, Gray E.

    3.20.7.2.1 Devolatilization 34 3.20.7.2.2 Boron and lithium isotopes 35 3.20.7.3 Carbon and Nitrogen forearcs. In addi- tion, subduction erosion from the forearc hanging walls can impact geochemical evolut

  12. 5, 547577, 2008 Isotope hydrology of

    E-Print Network [OSTI]

    Boyer, Edmond

    HESSD 5, 547­577, 2008 Isotope hydrology of cave dripwaters L. Fuller et al. Title Page Abstract.hydrol-earth-syst-sci-discuss.net/5/547/2008/ © Author(s) 2008. This work is licensed under a Creative Commons License. Hydrology and Earth System Sciences Discussions Papers published in Hydrology and Earth System Sciences Discussions

  13. Radioactive isotopes in Danish drinking water

    E-Print Network [OSTI]

    Radioactive isotopes in Danish drinking water Sven P. Nielsen Risø National Laboratory Working OF INVESTIGATION 11 3 DESCRIPTION OF INVESTIGATION 12 4 RADIOACTIVITY IN DRINKING WATER 13 5 SAMPLING 15 6 27 #12;4 #12;5 Preface This project for investigation of radioactivity in drinking water shall

  14. Atomic-vapor-laser isotope separation

    SciTech Connect (OSTI)

    Davis, J.I.

    1982-10-01T23:59:59.000Z

    This paper gives a brief history of the scientific considerations leading to the development of laser isotope separation (LIS) processes. The close relationship of LIS to the broader field of laser-induced chemical processes is evaluated in terms of physical criteria to achieve an efficient production process. Atomic-vapor LIS processes under development at Livermore are reviwed. 8 figures.

  15. MAGNESIUM ISOTOPE EVIDENCE FOR SINGLE STAGE FORMATION OF CB CHONDRULES BY COLLIDING PLANETESIMALS

    SciTech Connect (OSTI)

    Olsen, Mia B.; Schiller, Martin; Krot, Alexander N.; Bizzarro, Martin [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Copenhagen DK-1350 (Denmark)] [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Copenhagen DK-1350 (Denmark)

    2013-10-10T23:59:59.000Z

    Chondrules are igneous spherical objects preserved in chondritic meteorites and believed to have formed during transient heating events in the solar protoplanetary disk. Chondrules present in the metal-rich CB chondrites show unusual chemical and petrologic features not observed in other chondrite groups, implying a markedly distinct formation mechanism. Here, we report high-precision Mg-isotope data for 10 skeletal olivine chondrules from the Hammadah al Hamra 237 (HH237) chondrite to probe the formation history of CB chondrules. The {sup 27}Al/{sup 24}Mg ratios of individual chondrules are positively correlated to their stable Mg-isotope composition (?{sup 25}Mg), indicating that the correlated variability was imparted by a volatility-controlled process (evaporation/condensation). The mass-independent {sup 26}Mg composition (?{sup 26}Mg*) of chondrules is consistent with single stage formation from an initially homogeneous magnesium reservoir if the observed ?{sup 25}Mg variability was generated by non-ideal Rayleigh-type evaporative fractionation characterized by a ? value of 0.5142, in agreement with experimental work. The magnitude of the mass-dependent fractionation (?300 ppm) is significantly lower than that suggested by the increase in {sup 27}Al/{sup 24}Mg values, indicating substantial suppression of isotopic fractionation during evaporative loss of Mg, possibly due to evaporation at high Mg partial pressure. Thus, the Mg-isotope data of skeletal chondrules from HH237 are consistent with their origin as melts produced in the impact-generated plume of colliding planetesimals. The inferred ?{sup 26}Mg* value of –3.87 ± 0.93 ppm for the CB parent body is significantly lower than the bulk solar system value of 4.5 ± 1.1 ppm inferred from CI chondrites, suggesting that CB chondrites accreted material comprising an early formed {sup 26}Al-free component.

  16. Use of plutonium isotope activity ratios in dating recent sediments. [/sup 238/Pu//sup 239/Pu + /sup 240/Pu

    SciTech Connect (OSTI)

    Beasley, T. M.

    1982-01-01T23:59:59.000Z

    The majority of plutonium presently in the biosphere has come from the testing of nuclear devices. In the early 1950s, the Pu-238/239+240 activity ratio of fallout debris was > 0.04; in the more extensive test series of 1961 to 1962, the Pu-238/239+240 activity ratios were quite consistent at 0.02 to 0.03 and maximum fallout delivery occurred in mid-1963. A significant perturbation in Pu isotope activity ratios occurred in mid-1966 with the deposition of Pu-238 from the SNAP-9A reentry and burn-up. Recently deposited sediments have recorded these events and where accumulation rates are rapid (> 1 cm/y), changes in Pu isotope activity ratios can be used as a geochronological tool.

  17. Stable carbon isotope ratio of polycyclic aromatic hydrocarbons (PAHs) in the environment: validation of isolation and stable carbon isotope analysis methods

    E-Print Network [OSTI]

    Kim, Moon Koo

    2004-11-15T23:59:59.000Z

    , purification and compound specific isotope analysis methods were developed to accurately measure the stable carbon isotope ratio of individual PAHs. Development of the method included improving accuracy and precision of the isotopic measurement by producing...

  18. Measurement of Ultra-Low Potassium Contaminations with Accelerator Mass Spectrometry

    E-Print Network [OSTI]

    Dong, K J

    2007-01-01T23:59:59.000Z

    Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Among the radio-isotopes, $\\k40$ is one of the most abundant and yet whose signatures are difficult to reject. Procedures were devised to measure trace potassium concentrations in the inorganic salt CsI as well as in organic liquid scintillator (LS) with Accelerator Mass Spectrometry (AMS), giving, respectively, the $\\k40$-contamination levels of $\\sim 10^{-10}$ and $\\sim 10^{-13}$ g/g. Measurement flexibilities and sensitivities are improved over conventional methods. The projected limiting sensitivities if no excess of potassium signals had been observed over background are $8 \\times 10^{-13}$ g/g and $3 \\times 10^{-17}$ g/g for the CsI and LS, respectively. Studies of the LS samples indicate that the radioactive contaminations come mainly in the dye solutes, while the base solvents are orders of magnitude cleaner. The work demonstrate the possibilities of measuring naturally-occurring isoto...

  19. Mass spectrometric immunoassay

    DOE Patents [OSTI]

    Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

    2013-07-16T23:59:59.000Z

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

  20. Mass spectrometric immunoassay

    DOE Patents [OSTI]

    Nelson, Randall W (Phoenix, AZ); Williams, Peter (Phoenix, AZ); Krone, Jennifer Reeve (Granbury, TX)

    2007-12-04T23:59:59.000Z

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

  1. Physics with Rare Isotope Beams

    SciTech Connect (OSTI)

    Segel, Ralph E. [Northwestern University] [Northwestern University

    2013-11-08T23:59:59.000Z

    Using stable and radioactive beams provided by ATLAS nuclear reactions of special interest in astrophysics have been studied with emphasis on breakout from the hot CNO cycle to the rp-process. The masses of nuclear fragments provided by a strong fission source have been measured in order to help trace the path of the r process. 8Li ions produced by the d(7Li,8Li)n reaction have been trapped and the electrons and alphas emitted in the ensuing beta-decay measured. The neutrino directions were therefore determined, which leads to a measurement of the electron-neutrino correlation. The energies and kinematics are such that a sensitive search for any tensor admixture could be performed and an upper limit of 0.6% was placed on any such admixture. Earlier work on the electromagnetic form factors of the proton was extended. Graduate students were active participants in all of these eperiments, which formed the basis for six PhD theses.

  2. The atoms may be charged or neutral (how?) mass range: 1.67 10-27

    E-Print Network [OSTI]

    : where does our food come from? different plants have a different isotope content What other uses (2008) *mention UCSB project "Children of the corn" #12; Can we get energy from atoms? ... fusion and fission "The sun is a mass of incandescent gas A gigantic nuclear furnace Where hydrogen is built

  3. Compilation of the Dakota Aquifer Project isotope data and publications: The Isotope Hydrology Program of the Isotope Sciences Division

    SciTech Connect (OSTI)

    Davisson, M.L.; Smith, D.K.; Hudson, G.B.; Niemeyer, S. [Lawrence Livermore National Lab., CA (United States); Macfarlane, P.A.; Whittemore, D.O. [Kansas Geological Survey, Lawrence, KS (United States)

    1995-01-01T23:59:59.000Z

    In FY92 the then Nuclear Chemistry Division embarked on a scientific collaboration with the Kansas Geological Survey (KGS) to characterize with isotope techniques groundwater of the Dakota Formation of Kansas. The Dakota Formation is a Cretaceous-aged marine sandstone hosting potable groundwater in most regions of Kansas whose use will serve to partially offset the severe overdraft problems in the overlying Ogallala Formation. The isotope characterization of the Dakota groundwater has generated data that delineates sources, ages, and subsurface controls on the water quality. Initial interpretations of the data have been published in abstract volumes of (1) the 1993 Geological Society of America National Meeting, (2) the 8th International Conference on Geochronology, Cosmochronology and Isotope Geology, and (3) the 1994 Dakota Aquifer Workshop and Clinic. Copies of all abstracts are included in this brief review. One report will focus on the sources and ages of the groundwater, and the other will focus on the subsurface controls on the natural water quality.

  4. Imaging mass spectrometer with mass tags

    DOE Patents [OSTI]

    Felton, James S.; Wu, Kuang Jen; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2010-06-01T23:59:59.000Z

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  5. Imaging mass spectrometer with mass tags

    DOE Patents [OSTI]

    Felton, James S.; Wu, Kuang Jen J.; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2013-01-29T23:59:59.000Z

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  6. Importance of the Equlibrium Node in Preventing the Voltage Collapse Occurs in the Wind Power System

    E-Print Network [OSTI]

    Lavaei, Javad

    Importance of the Equlibrium Node in Preventing the Voltage Collapse Occurs in the Wind Power collapse will occurs in a wind power system is discussed next. The method of power flow calculation is the specific analysis of a given simplified wind power system. Keywords--voltage collapse; Newton

  7. Diffusional exchange of isotopes in a metal hydride sphere.

    SciTech Connect (OSTI)

    Wolfer, Wilhelm G.; Hamilton, John C.; James, Scott Carlton

    2011-04-01T23:59:59.000Z

    This report describes the Spherical Particle Exchange Model (SPEM), which simulates exchange of one hydrogen isotope by another hydrogen isotope in a spherical metal hydride particle. This is one of the fundamental physical processes during isotope exchange in a bed of spherical metal particles and is thus one of the key components in any comprehensive physics-based model of exchange. There are two important physical processes in the model. One is the entropy of mixing between the two isotopes; the entropy of mixing is increased by having both isotopes randomly placed at interstitial sites on the lattice and thus impedes the exchange process. The other physical process is the elastic interaction between isotope atoms on the lattice. The elastic interaction is the cause for {beta}-phase formation and is independent of the isotope species. In this report the coupled diffusion equations for two isotopes in the {beta}-phase hydride are solved. A key concept is that the diffusion of one isotope depends not only on its concentration gradient, but also on the concentration gradient of the other isotope. Diffusion rate constants and the chemical potentials for deuterium and hydrogen in the {beta}-phase hydride are reviewed because these quantities are essential for an accurate model of the diffusion process. Finally, a summary of some of the predictions from the SPEM model are provided.

  8. Coal fly ash interaction with environmental fluids: Geochemical and strontium isotope results from combined column and batch leaching experiments

    SciTech Connect (OSTI)

    Brubaker, Tonya M.; Stewart, Brian W.; Capo, Rosemary C.; Schroeder, Karl T.; Chapman, Elizabeth C.; Spivak-Birndorf, Lev J.; Vesper, Dorothy J.; Cardone, Carol R.; Rohar, Paul C.

    2013-05-01T23:59:59.000Z

    The major element and Sr isotope systematics and geochemistry of coal fly ash and its interactions with environmental waters were investigated using laboratory flow-through column leaching experiments (sodium carbonate, acetic acid, nitric acid) and sequential batch leaching experiments (water, acetic acid, hydrochloric acid). Column leaching of Class F fly ash samples shows rapid release of most major elements early in the leaching procedure, suggesting an association of these elements with soluble and surface bound phases. Delayed release of certain elements (e.g., Al, Fe, Si) signals gradual dissolution of more resistant silicate or glass phases as leaching continues. Strontium isotope results from both column and batch leaching experiments show a marked increase in {sup 87}Sr/{sup 86}Sr ratio with continued leaching, yielding a total range of values from 0.7107 to 0.7138. For comparison, the isotopic composition of fluid output from a fly ash impoundment in West Virginia falls in a narrow range around 0.7124. The experimental data suggest the presence of a more resistant, highly radiogenic silicate phase that survives the combustion process and is leached after the more soluble minerals are removed. Strontium isotopic homogenization of minerals in coal does not always occur during the combustion process, despite the high temperatures encountered in the boiler. Early-released Sr tends to be isotopically uniform; thus the Sr isotopic composition of fly ash could be distinguishable from other sources and is a useful tool for quantifying the possible contribution of fly ash leaching to the total dissolved load in natural surface and ground waters.

  9. Isotope shifts of natural Sr+ measured by laser fluorescence in a sympathetically cooled Coulomb crystal

    E-Print Network [OSTI]

    Brice Dubost; Romain Dubessy; Benjamin Szymanski; Samuel Guibal; Jean-Pierre Likforman; Luca Guidoni

    2014-02-14T23:59:59.000Z

    We measured by laser spectroscopy the isotope shifts between naturally-occurring even-isotopes of strontium ions for both the $5s\\,\\,^2S_{1/2}\\to 5p\\,\\,^2P_{1/2}$ (violet) and the $4d\\,\\,^2D_{3/2}\\to 5p\\,\\,^2P_{1/2}$ (infrared) dipole-allowed optical transitions. Fluorescence spectra were taken by simultaneous measurements on a two-component Coulomb crystal in a linear Paul trap containing $10^3$--$10^4$ laser-cooled Sr$^+$ ions. The isotope shifts are extracted from the experimental spectra by fitting the data with the analytical solution of the optical Bloch equations describing a three-level atom in interaction with two laser beams. This technique allowed us to increase the precision with respect to previously reported data obtained by optogalvanic spectroscopy or fast atomic-beam techniques. The results for the $5s\\,\\,^2S_{1/2}\\to 5p\\,\\,^2P_{1/2}$ transition are $\

  10. Far Infrared Conductivity of Charge Density Wave Materials and the Oxygen Isotope Effect in High-T{sub c}

    E-Print Network [OSTI]

    Creager, W.N.

    2009-01-01T23:59:59.000Z

    determined. With 180 isotope enrichments of approximatelyand consistent 180 isotope enrichments of approximately 80%.enrichment, 0.90; the same group has reported oxygen isotope

  11. Isotope Shifts in Beryllium-, Boron-, Carbon-, and Nitrogen-like Ions from Relativistic Configuration Interaction Calculations

    E-Print Network [OSTI]

    Nazé, C; Rynkun, P; Gaigalas, G; Godefroid, M; Jönsson, P

    2014-01-01T23:59:59.000Z

    Energy levels, normal and specific mass shift parameters as well as electronic densities at the nucleus are reported for numerous states along the beryllium, boron, carbon, and nitrogen isoelectronic sequences. Combined with nuclear data, these electronic parameters can be used to determine values of level and transition isotope shifts. The calculation of the electronic parameters is done using first-order perturbation theory with relativistic configuration interaction wave functions that account for valence, core-valence and core-core correlation effects as zero-order functions. Results are compared with experimental and other theoretical values, when available.

  12. Beta-decay properties of Zr and Mo neutron-rich isotopes

    E-Print Network [OSTI]

    P. Sarriguren; J. Pereira

    2010-06-08T23:59:59.000Z

    Gamow-Teller strength distributions, beta-decay half-lives, and beta-delayed neutron emission are investigated in neutron-rich Zr and Mo isotopes within a deformed quasiparticle random-phase approximation. The approach is based on a self-consistent Skyrme Hartree-Fock mean field with pairing correlations and residual separable particle-hole and particle-particle forces. Comparison with recent measurements of half-lives stresses the important role that nuclear deformation plays in the description of beta-decay properties in this mass region.

  13. Nonadiabatic calculations of ultraviolet absorption cross section of sulfur monoxide: Isotopic effects on the photodissociation reaction

    SciTech Connect (OSTI)

    Danielache, Sebastian O.; Tomoya, Suzuki; Nanbu, Shinkoh [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Chiyoda Ku, Tokyo 102-8554 (Japan)] [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Chiyoda Ku, Tokyo 102-8554 (Japan); Kondorsky, Alexey [P. N. Lebedev Physical Institute of Russian Academy of Science, Leninsky pr., 53, Moscow, 119991 (Russian Federation) [P. N. Lebedev Physical Institute of Russian Academy of Science, Leninsky pr., 53, Moscow, 119991 (Russian Federation); Moscow Institute of Physics and Technology (State University), Institutsky per., 9, Dolgoprudny Moscow region, 141700 (Russian Federation); Tokue, Ikuo [Department of Chemistry, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181 (Japan)] [Department of Chemistry, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181 (Japan)

    2014-01-28T23:59:59.000Z

    Ultraviolet absorption cross sections of the main and substituted sulfur monoxide (SO) isotopologues were calculated using R-Matrix expansion technique. Energies, transition dipole moments, and nonadiabatic coupling matrix elements were calculated at MRCI/AV6Z level. The calculated absorption cross section of {sup 32}S{sup 16}O was compared with experimental spectrum; the spectral feature and the absolute value of photoabsorption cross sections are in good agreement. Our calculation predicts a long lived photoexcited SO* species which causes large non-mass dependent isotopic effects depending on the excitation energy in the ultraviolet region.

  14. Excitation energy and strength of the pygmy dipole resonance in stable tin isotopes

    E-Print Network [OSTI]

    B. Özel; J. Enders; H. Lenske; P. von Neumann-Cosel; I. Poltoratska; V. Yu. Ponomarev; A. Richter; D. Savran; N. Tsoneva

    2009-01-16T23:59:59.000Z

    The $^{112,120}$Sn$(\\gamma,\\gamma')$ reactions have been studied at the S-DALINAC. Electric dipole (E1) strength distributions have been determined including contributions from unresolved strength extracted by a fluctuation analysis. Together with available data on $^{116,124}$Sn, an experimental systematics of the pygmy dipole resonance (PDR) in stable even-mass tin isotopes is established. The PDR centroid excitation energies and summed strengths are in reasonable agreement with quasiparticle-phonon model calculations based on a nonrelativistic description of the mean field but disagree with relativistic quasiparticle random-phase approximation predictions.

  15. Optically pumped isotopic ammonia laser system

    DOE Patents [OSTI]

    Buchwald, Melvin I. (Santa Fe, NM); Jones, Claude R. (Los Alamos, NM); Nelson, Leonard Y. (Seattle, WA)

    1982-01-01T23:59:59.000Z

    An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.

  16. Concerning the Facility for Rare Isotope Beams

    ScienceCinema (OSTI)

    Symons, James

    2013-05-29T23:59:59.000Z

    James Symons, Nuclear Science Division Director at Lawrence Berkeley Lab, and Daniela Leitner, head of operations at Berkeley Lab's 88-Inch Cyclotron, discuss major contributions to the new Facility for Rare Isotope Beams (FRIB) at Michigan State University, including ion source, which will based on the VENUS source built for the 88-Inch Cyclotron, and the GRETA gamma-ray detector now under construction there.

  17. Neutrino mass matrix

    SciTech Connect (OSTI)

    Capps, R.H.; Strobel, E.L.

    1985-07-01T23:59:59.000Z

    It is assumed that the Dirac mass matrix for the neutrinos (..nu../sub e/,..nu../sub ..mu../,..nu../sub tau/) is similar in form to those for the quarks and charged leptons, and that the smallness of the observed ..nu.. masses results from the Gell-Mann--Ramond--Slansky mechanism. It is shown that if certain tentative experimental results concerning the ..nu.. masses and mixing angles are confirmed, significant limitations may be placed on the Majorana mass matrix. The most satisfactory simple assumption concerning the Majorana mass matrix is that it is approximately proportional to the Dirac mass matrix. Some general properties of the Dirac matrices are discussed.

  18. Hydrogen isotope separation utilizing bulk getters

    DOE Patents [OSTI]

    Knize, Randall J. (Los Angeles, CA); Cecchi, Joseph L. (Lawrenceville, NJ)

    1990-01-01T23:59:59.000Z

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

  19. Hydrogen isotope separation utilizing bulk getters

    DOE Patents [OSTI]

    Knize, Randall J. (Los Angeles, CA); Cecchi, Joseph L. (Lawrenceville, NJ)

    1991-01-01T23:59:59.000Z

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

  20. FILTR: Flash Isotope Library and Training Resource

    SciTech Connect (OSTI)

    Campbell, D; Trombino, D

    2007-07-26T23:59:59.000Z

    The subject of radiation detection is replete with complex concepts and challenging nomenclature. Furthermore, a daunting variety of radioactive isotopes may be encountered during the routine operation of a radiation detector. Individuals tasked with searching for illicit sources of radiation must remain vigilant while navigating through more frequently encountered mundane and legitimate radioactive sources. The Flash Isotope Library and Training Resource (FILTR) is being developed as an easily accessible and intuitive reference tool to manage the high volume of complex information required for this task. FILTR is an extended version of the Primary Utility for Nuclear Terminology (PUNT) software developed by the Counter Measures Test Beds group at Lawrence Livermore National Laboratory for the United States Secret Service. Authored in the Flash multimedia development environment, FILTR contains detailed information on potentially encountered isotopes as well as training on radiation and operational procedures. Reference material is organized to present critical information quickly while facilitating more in-depth investigation through an intuitive interface and engaging content. FILTR is being developed for a diverse audience of law enforcement organizations and government agencies and a wide range of skill sets from expert analysts to officers whose primary role is not radiation detection. Additionally, the wide compatibility of Flash content will allow FILTR to be readily accessible through the growing number of multi-media enabled electronic devices, including PDAs and cellular phones.

  1. Hydrogen isotope separation utilizing bulk getters

    DOE Patents [OSTI]

    Knize, R.J.; Cecchi, J.L.

    1991-08-20T23:59:59.000Z

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen. 4 figures.

  2. Neutrinoless Double Beta Decay with Negligible Neutrino Mass

    E-Print Network [OSTI]

    Biswajoy Brahmachari; Ernest Ma

    2002-02-27T23:59:59.000Z

    If the electron neutrino has an effective nonzero Majorana mass, then neutrinoless double beta decay will occur. However, the latter is possible also with a negligible neutrino mass. We show how this may happen in a simple model of scalar diquarks and dileptons. This possibility allows neutrino masses to be small and hierarchical, without conflicting with the possible experimental evidence of neutrinoless double beta decay.

  3. Stable isotope fractionation by thermal diffusion through partially molten wet and dry silicate rocks

    E-Print Network [OSTI]

    Bindeman, Ilya N.

    isotope redistribution by thermal diffusion leading to enrichment of light isotopes at the hot endStable isotope fractionation by thermal diffusion through partially molten wet and dry silicate 2012 Editor: T.M. Harrison Keywords: thermal diffusion hydrogen isotope separation oxygen isotopes

  4. Conditions under which cracks occur in modified 13% chromium steel in wet hydrogen sulfide environments

    SciTech Connect (OSTI)

    Hara, T.; Asahi, H.

    2000-05-01T23:59:59.000Z

    Occurrence of cracks in an API 13% Cr steel, modified 13% Cr steel, and duplex stainless steel were compared in various wet, mild hydrogen sulfide (H{sub 2}S) environments. The conditions under which cracks occurred in the modified 13% Cr steel in oil and gas production environments were made clear. No cracks occurred if pH > depassivation pH (pH{sub d}) and redox potential of sulfur (E{sub S(red/ax)}) < pitting potential (V{sub c}). Hydrogen embrittlement-type cracks occurred in pH > Ph{sub d} and E{sub S(red/ax)} > V{sub c}. The pH inside the pit decreased drastically and hydrogen embrittlement occurred. Cracks of the hydrogen embrittlement type occurred if pH < pH{sub d} and threshold hydrogen concentration under which cracks occur (H{sub th}) < hydrogen concentration in steel (H{sub 0}). No cracks occurred if pH < pH{sub d} and H{sub th} > H{sub 0}.

  5. Small system for tritium accelerator mass spectrometry

    DOE Patents [OSTI]

    Roberts, M.L.; Davis, J.C.

    1993-02-23T23:59:59.000Z

    Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and [sup 3]He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

  6. Small system for tritium accelerator mass spectrometry

    DOE Patents [OSTI]

    Roberts, Mark L. (Livermore, CA); Davis, Jay C. (Livermore, CA)

    1993-01-01T23:59:59.000Z

    Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

  7. Climate change deduced from isotopes in tree rings

    SciTech Connect (OSTI)

    Pendall, E.G.; Leavitt, S.W.

    1997-11-01T23:59:59.000Z

    This paper describes the theory of carbon, hydrogen, and oxygen isotopic signatures in cellulose for the purpose of paleoclimatic reconstruction. Mechanisms governing tree ring cellulose isotopic variability are investigated, and applications to the southwestern United States are delineated. A monitoring program of pinyon trees and comparison to climatic parameters is briefly described. Variables measured included deviations in hydrogen and oxygen-18 isotopic composition in precipitation, soil water, stem and leaf water, and atmospheric vapor. Water from phloem tissue was found to be isotopically identical to the xylem sap, suggesting that cellulose precursors can exchange isotopically with source water before cellulose is made in the trunk, thus removing most of the isotopic signal from the leaves. Overall results suggest that, on arid sites in the southwestern US receiving adequate summer rain, a precipitation seasonality signal may be recorded. 21 refs., 2 figs.

  8. EMSL - Mass Spectrometry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    mass-spectrometry Proteomics Capabilities High resolution and mass accuracy Fourier-transform ion cyclotron resonance (FT-ICR) spectrometers, from 6 Tesla (T) to 15T and 21T in...

  9. Quark masses, the Dashen phase, and gauge field topology

    SciTech Connect (OSTI)

    Creutz, Michael, E-mail: creutz@bnl.gov

    2013-12-15T23:59:59.000Z

    The CP violating Dashen phase in QCD is predicted by chiral perturbation theory to occur when the up–down quark mass difference becomes sufficiently large at fixed down-quark mass. Before reaching this phase, all physical hadronic masses and scattering amplitudes are expected to behave smoothly with the up-quark mass, even as this mass passes through zero. In Euclidean space, the topological susceptibility of the gauge fields is positive at positive quark masses but diverges to negative infinity as the Dashen phase is approached. A zero in this susceptibility provides a tentative signal for the point where the mass of the up quark vanishes. I discuss potential ambiguities with this determination. -- Highlights: •The CP violating Dashen phase in QCD occurs when the up quark mass becomes sufficiently negative. •Before reaching this phase, all physical hadronic masses and scattering amplitudes behave smoothly with the up-quark mass. •The topological susceptibility of the gauge fields diverges to negative infinity as the Dashen phase is approached. •A zero in the topological susceptibility provides a tentative signal for the point where the mass of the up quark vanishes. •The universality of this definition remains unproven. Potential ambiguities are discussed.

  10. System and method for high precision isotope ratio destructive analysis

    DOE Patents [OSTI]

    Bushaw, Bruce A; Anheier, Norman C; Phillips, Jon R

    2013-07-02T23:59:59.000Z

    A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).

  11. Elbow mass flow meter

    DOE Patents [OSTI]

    McFarland, Andrew R. (College Station, TX); Rodgers, John C. (Santa Fe, NM); Ortiz, Carlos A. (Bryan, TX); Nelson, David C. (Santa Fe, NM)

    1994-01-01T23:59:59.000Z

    Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

  12. Enriched Stable Isotope Materials and Chemistry | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Chemistry SHARE Enriched Stable Isotope Materials and Chemistry Reductiondistillation of calcium-48 metal valued at over 900,000. An inventory of 2,300 batches of...

  13. Copper isotope fractionation in acid mine drainage. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in acid mine drainage. Abstract: We surveyed the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed located in...

  14. actinium isotopes including: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Topic Index 1 Discovery of the actinium, thorium, protactinium, and uranium isotopes CERN Preprints Summary: Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium...

  15. actinium isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Topic Index 1 Discovery of the actinium, thorium, protactinium, and uranium isotopes CERN Preprints Summary: Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium...

  16. Isotopic Analysis- Fluid At Roosevelt Hot Springs Geothermal...

    Open Energy Info (EERE)

    Details Location Roosevelt Hot Springs Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date 1981 - 1981 Usefulness useful DOE-funding Unknown Exploration...

  17. Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal...

    Open Energy Info (EERE)

    Activity: Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal Area (1990) Exploration Activity Details Location Indian Valley Hot Springs Geothermal Area...

  18. Helium isotopes in geothermal systems- Iceland, The Geysers,...

    Open Energy Info (EERE)

    Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Helium isotopes in geothermal systems- Iceland, The Geysers, Raft River and Steamboat Springs...

  19. Isotopic Analysis At Nw Basin & Range Region (Kennedy & Van Soest...

    Open Energy Info (EERE)

    useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced...

  20. Isotopic Analysis At Northern Basin & Range Region (Kennedy ...

    Open Energy Info (EERE)

    useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced...

  1. Isotopic Analysis At Central Nevada Seismic Zone Region (Kennedy...

    Open Energy Info (EERE)

    useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced...

  2. Isotopic Analysis At Walker-Lane Transitional Zone Region (Kennedy...

    Open Energy Info (EERE)

    useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced...

  3. Isotopic Analysis- Fluid At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Farrar, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Long Valley Caldera Geothermal Area (Farrar, Et...

  4. Sulfur Isotopes as Indicators of Amended Bacterial Sulfate Reduction...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Amended Bacterial Sulfate Reduction Processes Influencing Field Scale Uranium Bioremediation. Sulfur Isotopes as Indicators of Amended Bacterial Sulfate Reduction Processes...

  5. anomalous isotope effect: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the following recombination Reid, Scott A. 4 Anomalous quantum and isotope effects in water clusters: Physical phenomenon, model artifact, or bad approximation? CERN Preprints...

  6. Geothermal reservoir temperatures estimated from the oxygen isotope...

    Open Energy Info (EERE)

    reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes Jump to: navigation, search OpenEI...

  7. Geothermal Reservoir Temperatures Estimated from the Oxygen Isotope...

    Open Energy Info (EERE)

    Temperatures Estimated from the Oxygen Isotope Compositions of Dissolved Sulfate and Water from Hot Springs and Shallow Drillholes Jump to: navigation, search OpenEI Reference...

  8. An Oxygen Isotope Study Of Silicates In The Larderello Geothermal...

    Open Energy Info (EERE)

    Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: An Oxygen Isotope Study Of Silicates In The Larderello Geothermal Field, Italy Abstract...

  9. Chemical And Isotopic Investigation Of Warm Springs Associated...

    Open Energy Info (EERE)

    water (high TDS, > 5000 mgl). Deviations from the meteoric water line are the result of rock-water isotopic exchange, mixing or evaporation. Fluid source regions and residence...

  10. Hydrogeological And Isotopic Survey Of Geothermal Fields In The...

    Open Energy Info (EERE)

    Hydrogeological And Isotopic Survey Of Geothermal Fields In The Buyuk Menderes Graben, Turkey Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  11. Isotopic Analysis At Long Valley Caldera Geothermal Area (Evans...

    Open Energy Info (EERE)

    Isotopic Analysis At Long Valley Caldera Geothermal Area (Evans, Et Al., 2002) Exploration Activity Details Location Long Valley Caldera Geothermal Area Exploration Technique...

  12. Isotopic Analysis- Fluid At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Gerlach, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Long Valley Caldera Geothermal Area (Taylor & Gerlach,...

  13. Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From...

    Open Energy Info (EERE)

    Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From Yellowstone Drill Cores Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Oxygen...

  14. Isotopic Composition of Carbon in Fluids from the Long Valley...

    Open Energy Info (EERE)

    Isotopic Composition of Carbon in Fluids from the Long Valley Geothermal System, California, In- Proceedings of the Second Workshop on Hydrologic and Geochemical Monitoring in the...

  15. Mantle Helium And Carbon Isotopes In Separation Creek Geothermal...

    Open Energy Info (EERE)

    Mantle Helium And Carbon Isotopes In Separation Creek Geothermal Springs, Three Sisters Area, Central Oregon- Evidence For Renewed Volcanic Activity Or A Long Term Steady State...

  16. antimony isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1 Hartmut Bracht 258 Late Pleistocene C4 Plant Dominance and Summer Rainfall in the Southwestern United States from Isotopic Study of Herbivore Teeth Geosciences Websites Summary:...

  17. Stable carbon and nitrogen isotope enrichment in primate tissues

    E-Print Network [OSTI]

    Crowley, Brooke E.; Carter, Melinda L.; Karpanty, Sarah M.; Zihlman, Adrienne L.; Koch, Paul L.; Dominy, Nathaniel J.

    2010-01-01T23:59:59.000Z

    and nitrogen isotope enrichment in primate tissues Brooke E.and nitrogen apparent enrichment (e*) values ± one standardexplored the apparent enrichment (e*) between bone collagen

  18. Contamination Cross-contamination occurs when bacteria, or "germs," are moved from one food to another.

    E-Print Network [OSTI]

    Combat Cross Contamination Cross-contamination occurs when bacteria, or "germs," are moved from one food to another. To combat cross-contamination, keep foods SEPARATE!! At the grocery store, keep raw

  19. USE OF NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS...

    Open Energy Info (EERE)

    IN THE COSO EGS PROJECT Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: USE OF NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE...

  20. SIEMENS ADVANCED QUANTRA FTICR MASS SPECTROMETER FOR ULTRA HIGH RESOLUTION AT LOW MASS

    SciTech Connect (OSTI)

    Spencer, W; Laura Tovo, L

    2008-07-08T23:59:59.000Z

    The Siemens Advanced Quantra Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer was evaluated as an alternative instrument to large double focusing mass spectrometers for gas analysis. High resolution mass spectrometers capable of resolving the common mass isomers of the hydrogen isotopes are used to provide data for accurate loading of reservoirs and to monitor separation of tritium, deuterium, and helium. Conventional double focusing magnetic sector instruments have a resolution that is limited to about 5000. The Siemens FTICR instrument achieves resolution beyond 400,000 and could possibly resolve the tritium ion from the helium-3 ion, which differ by the weight of an electron, 0.00549 amu. Working with Y-12 and LANL, SRNL requested Siemens to modify their commercial Quantra system for low mass analysis. To achieve the required performance, Siemens had to increase the available waveform operating frequency from 5 MHz to 40 MHz and completely redesign the control electronics and software. However, they were able to use the previous ion trap, magnet, passive pump, and piezo-electric pulsed inlet valve design. NNSA invested $1M in this project and acquired four systems, two for Y-12 and one each for SRNL and LANL. Siemens claimed a $10M investment in the Quantra systems. The new Siemens Advanced Quantra demonstrated phenomenal resolution in the low mass range. Resolution greater than 400,000 was achieved for mass 2. The new spectrometer had a useful working mass range to 500 Daltons. However, experiments found that a continuous single scan from low mass to high was not possible. Two useful working ranges were established covering masses 1 to 6 and masses 12 to 500 for our studies. A compromise performance condition enabled masses 1 to 45 to be surveyed. The instrument was found to have a dynamic range of about three orders of magnitude and quantitative analysis is expected to be limited to around 5 percent without using complex fitting algorithms. Analysis of low concentration ions, at the ppm level, required a separate analysis using ion ejection techniques. Chemical ionization due to the formation of the MH{sup +} ion or MD{sup +} increased the complexity of the spectra compared to magnetic sector mass spectra and formation of the protonated or deuterated complex was a dynamic function of the trap ion concentration. This made quantitative measurement more of a challenge. However, the resolution of the instrument was far superior to any other mass spectrometry technique that has been applied to the analysis of the hydrogen isotopes. The piezo-electric picoliter injection device offers a new way of submitting small quantities of atmospheric pressure sample gas for analysis. The new software had many improvements over the previous version but significant flaws in the beta codes remain that make the prototype units less than ideal. The instrument is a promising new technology that experience will likely improve. Unfortunately, Siemens has concluded that the technology will not be a commercial success and has decided to stop producing this product.

  1. Descriptions of selected accidents that have occurred at nuclear reactor facilities

    SciTech Connect (OSTI)

    Bertini, H.W.

    1980-04-01T23:59:59.000Z

    This report was prepared at the request of the President's Commission on the Accident at Three Mile Island to provide the members of the Commission with some insight into the nature and significance of accidents that have occurred at nuclear reactor facilities in the past. Toward that end, this report presents a brief description of 44 accidents which have occurred throughout the world and which meet at least one of the severity criteria that were established.

  2. Validation of a Monte Carlo based depletion methodology via High Flux Isotope Reactor HEU post-irradiation examination measurements

    SciTech Connect (OSTI)

    Chandler, David [ORNL; Maldonado, G Ivan [ORNL; Primm, Trent [ORNL

    2010-01-01T23:59:59.000Z

    The purpose of this study is to validate a Monte Carlo based depletion methodology by comparing calculated post-irradiation uranium isotopic compositions in the fuel elements of the High Flux Isotope Reactor (HFIR) core to values measured using uranium mass-spectrographic analysis. Three fuel plates were analyzed: two from the outer fuel element (OFE) and one from the inner fuel element (IFE). Fuel plates O-111-8, O-350-1, and I-417-24 from outer fuel elements 5-O and 21-O and inner fuel element 49-I, respectively, were selected for examination. Fuel elements 5-O, 21-O, and 49-1 were loaded into HFIR during cycles 4, 16, and 35, respectively (mid to late 1960s). Approximately one year after each of these elements were irradiated, they were transferred to the High Radiation Level Examination Laboratory (HRLEL) where samples from these fuel plates were sectioned and examined via uranium mass-spectrographic analysis. The isotopic composition of each of the samples was used to determine the atomic percent of the uranium isotopes. A Monte Carlo based depletion computer program, ALEPH, which couples the MCNP and ORIGEN codes, was utilized to calculate the nuclide inventory at the end-of-cycle (EOC). A current ALEPH/MCNP input for HFIR fuel cycle 400 was modified to replicate cycles 4, 16, and 35. The control element withdrawal curves and flux trap loadings were revised, as well as the radial zone boundaries and nuclide concentrations in the MCNP model. The calculated EOC uranium isotopic compositions for the analyzed plates were found to be in good agreement with measurements, which reveals that ALEPH/MCNP can accurately calculate burn-up dependent uranium isotopic concentrations for the HFIR core. The spatial power distribution in HFIR changes significantly as irradiation time increases due to control element movement. Accurate calculation of the end-of-life uranium isotopic inventory is a good indicator that the power distribution variation as a function of space and time is accurately calculated, i.e. an integral check. Hence, the time dependent heat generation source terms needed for reactor core thermal hydraulic analysis, if derived from this methodology, have been shown to be accurate for highly enriched uranium (HEU) fuel.

  3. Oxygen isotope fractionation in the vacuum ultraviolet photodissociation of carbon monoxide: Wavelength, pressure and temperature dependency.

    E-Print Network [OSTI]

    Chakraborty, Subrata

    2013-01-01T23:59:59.000Z

    The extent of heavy isotope enrichment (? 17 O and ? 18 O)range of the heavy isotope enrichment (? 17 O and ? 18 O) isThe extent of heavy isotope enrichment (? 17 O and ? 18 O)

  4. GEOCHEMISTRY AND ISOTOPE HYDROLOGY OF GROUNDWATERS IN THE STRIPA GRANITE RESULTS AND PRELIMINARY INTERPRETATION

    E-Print Network [OSTI]

    Fritz, P.

    2011-01-01T23:59:59.000Z

    S. Italy). In Isotope Hydrology, IAEA Symposium. Sm-129/53,isotopic variations in hydrology. At. Energy Rev. 14: 621-70 GEOCHEMISTRY AND ISOTOPE HYDROLOGY OF GROUNDWATERS IN THE

  5. Comparison of atmospheric hydrology over convective continental regions using water vapor isotope measurements from space

    E-Print Network [OSTI]

    . Correlation analysis shows that mixing with boundary layer air, enhanced isotopic fractionation during precipitation, and subsiding air parcels contribute to intraseasonal isotopic variability. These local controls distillation in a Lagrangrian framework underestimates the observed isotopic depletion during the monsoons

  6. Chemical and Isotopic Evidence of Steam Upflow and Partial Condensation in Los Azufres Reservoir

    SciTech Connect (OSTI)

    Nieva, D.; Verma, M.; Santoyo, E.; Barragan, R.M.; Portugal, E.; Ortiz, J.; Quijano, J.L.

    1987-01-20T23:59:59.000Z

    Data of chemical and isotopic composition of fluids from Los Azufres wells, collected over a two year period, provide evidence of a process of upward flow and partial condensation of steam in the reservoir, which explains part of the previously reported heterogeneity in isotopic composition of the liquid phase (Nieva et al, 1983). For the southern part of the field, a direct correlation is found between chloride and oxygen-18 concentrations, and an inverse correlation between these parameters and deuterium and carbon dioxide concentrations in the liquid phase of the reservoir. Chloride ion concentrations increase gradually from ca 660 ppm in the production zones of shallow wells to ca 1900 ppm in the case of deep wells. This observation agrees with predictions based on the well-known model for vapor dominated systems of White et al (1971). For the northern part of the field the same correlations are observed, except for the deuterium concentration which in this case correlates directly with oxygen-18. It is concluded that the same process of steam upflow occurs in the northern section but that some other process — perhaps a mixture with other hydrothermal fluid — is also occurring. 3 tabs., 16 refs., 8 figs.

  7. Isotope Specific Remediation Media and Systems - 13614

    SciTech Connect (OSTI)

    Denton, Mark S.; Mertz, Joshua L. [Kurion, Inc. Oak Ridge, Tennessee 37831 (United States)] [Kurion, Inc. Oak Ridge, Tennessee 37831 (United States); Morita, Keisuke [Japan Atomic Energy Agency, Tokai Research and Development Center, Fukushima Project Team, Tokai-mura, Ibaraki-ken, 319-1195 (Japan)] [Japan Atomic Energy Agency, Tokai Research and Development Center, Fukushima Project Team, Tokai-mura, Ibaraki-ken, 319-1195 (Japan)

    2013-07-01T23:59:59.000Z

    On March 11, 2011, now two years ago, the magnitude 9.0 Great East Japan earthquake, Tohoku, hit off the Fukushima coast of Japan. While, of course, most of the outcome of this unprecedented natural and manmade disaster was a negative, both in Japan and worldwide, there have been some extremely invaluable lessons learned and new emergency recovery technologies and systems developed. As always, the mother of invention is necessity. Among these developments has been the development and full-scale implementation of proven isotope specific media (ISMs) with the intent of surgically removing specific hazardous isotopes for the purpose of minimizing dose to workers and the environment. The first such ISMs to be deployed at the Fukushima site were those removing cesium (Cs-137) and iodine (I-129). Since deployment on June 17, 2011, along with treated cooling water recycle, some 70% of the curies in the building liquid wastes have been removed by the Kurion system alone. The current levels of cesium are now only 2% of the original levels. Such an unprecedented, 'external cooling system' not only allowed the eventual cold shut down of the reactors in mid-December, 2011, but has allowed workers to concentrate on the cleanup of other areas of the site. Water treatment will continue for quite some time due to continued leakage into the buildings and the eventual goal of cleaning up the reactors and fuel pools themselves. With the cesium removal now in routine operation, other isotopes of concern are likely to become priorities. One such isotope is that of strontium, and yttrium (Sr-90 and Y-90), which is still at original levels causing further dose issues as well as impediments to discharge of the treated waste waters. For over a year now, a new synthetic strontium specific media has been under development and testing both in our licensed facility in Oak Ridge, Tennessee, but also in confirmatory tests by the Japan Atomic Energy Agency (JAEA) in Japan for Tokyo Electric Power Company (TEPCO). The tests have proven quite successful, even in high salt conditions, and, with loading and dose calculations being completed, will be proposed to add to the existing cesium system. There is no doubt, as high gamma isotopes are removed, other recalcitrant isotopes such as this will require innovative removal media, systems and techniques. Also coming out of this international effort are other ISM media and systems that can be applied more broadly to both Commercial Nuclear Power Plants (NPPs) as well as in Department of Energy (DOE) applications. This cesium and strontium specific media has further been successfully tested in 2012 at a Magnox station in the UK. The resulting proposed mitigation systems for pond and vault cleanup look quite promising. An extremely unusual ISM for carbon 14 (C-14), nickel (Ni-63) and cesium (Cs-137) has been developed for Diablo Canyon NPP for dose reduction testing in their fuel pool. These media will be deployed in Submersible Media Filter (SMF) and Submersible Columns (SC) systems adapted to standard Tri-Nuclear{sup R} housings common in the U.S. and UK. External Vessel Systems (mini-Fukushima) have also been developed as a second mitigation system for D and D and outages. Finally, technetium (Tc- 99) specific media developed for the Waste Treatment Plant (WTP) recycle or condensate (secondary) waste streams (WM 2011) are being further perfected and tested for At-Tank Tc-99 removal, as well as At Tank Cs media. In addition to the on-going media development, systems for deploying such media have developed over the last year and are in laboratory- and full-scale testing. These systems include the fore mentioned Submersible Media Filters (SMF), Submersible Columns (SC) and external pilot- and full-scale, lead-lag, canister systems. This paper will include the media development and testing, as well as that of the deployment systems themselves. (authors)

  8. Nitrous Oxide and Molecular Nitrogen Isotopic Compositions and Aerosol Optical Properties: Experiments and Observations Relevant to Planetary Atmospheres

    E-Print Network [OSTI]

    Croteau, Philip Louis

    2010-01-01T23:59:59.000Z

    Stratospheric enrichment, isotope-budgets and the 17O-18Olead to enrichments or depletions in the isotope ratios of

  9. Apparatus for isotopic alteration of mercury vapor

    DOE Patents [OSTI]

    Grossman, Mark W. (Belmont, MA); George, William A. (Gloucester, MA); Marcucci, Rudolph V. (Danvers, MA)

    1988-01-01T23:59:59.000Z

    An apparatus for enriching the isotopic Hg content of mercury is provided. The apparatus includes a reactor, a low pressure electric discharge lamp containing a fill including mercury and an inert gas. A filter is arranged concentrically around the lamp. In a preferred embodiment, constant mercury pressure is maintained in the filter by means of a water-cooled tube that depends from it, the tube having a drop of mercury disposed in it. The reactor is arranged around the filter, whereby radiation from said lamp passes through the filter and into said reactor. The lamp, the filter and the reactor are formed of a material which is transparent to ultraviolet light.

  10. Laser-assisted isotope separation of tritium

    DOE Patents [OSTI]

    Herman, Irving P. (Castro Valley, CA); Marling, Jack B. (Livermore, CA)

    1983-01-01T23:59:59.000Z

    Methods for laser-assisted isotope separation of tritium, using infrared multiple photon dissociation of tritium-bearing products in the gas phase. One such process involves the steps of (1) catalytic exchange of a deuterium-bearing molecule XYD with tritiated water DTO from sources such as a heavy water fission reactor, to produce the tritium-bearing working molecules XYT and (2) photoselective dissociation of XYT to form a tritium-rich product. By an analogous procedure, tritium is separated from tritium-bearing materials that contain predominately hydrogen such as a light water coolant from fission or fusion reactors.

  11. Strategic Isotope Production | ornl.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary900Steep SlopeStochastic WeeklyStoresStrategic Isotope

  12. Isotope Program Transportation | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011 Strategic2 OPAM Flash2011-12Approvedof EnergyWorld Design Challenge |Is aIsotope

  13. alpha-particle-emitting isotope 259db: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CERN Preprints Summary: Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For...

  14. alpha-active iridium isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CERN Preprints Summary: Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes have so far been observed; the discovery of these isotopes is discussed. For...

  15. Enriched Background Isotope Study (EBIS) Litter reciprocal transplant studies to understand sources, transport and

    E-Print Network [OSTI]

    1 Enriched Background Isotope Study (EBIS) Litter reciprocal transplant studies to understand were removed from this archived version.] #12;3 Enriched Background Isotope Study (EBIS): Litter

  16. Neutron Stimulated Emission Computed Tomography of Stable Isotopes

    E-Print Network [OSTI]

    on the development of a new molecular imaging technique using inelastic scattering of fast neutrons. Earlier studies characteristic gamma photons through inelastic scattering of an external neutron beam. These stable isotopes canNeutron Stimulated Emission Computed Tomography of Stable Isotopes Carey E. Floyd Jr.*ab , Calvin

  17. Hydrochemical and isotopic effects associated with petroleum fuel biodegradation pathways

    E-Print Network [OSTI]

    Sheffield, University of

    hydrocarbons and residual electron acceptors have been used to deduce BTEX and MTBE degradation pathways. Benzene and MTBE persist into the denitrification zone, with carbon isotope enrichment of benzene-enrichment of residual benzene gives an apparent e value of Ã?0.66x. MTBE shows no significant isotopic enrichment (d13 C

  18. Quantifying intrapopulation variability in stable isotope data for Spotted Seatrout

    E-Print Network [OSTI]

    111 Quantifying intrapopulation variability in stable isotope data for Spotted Seatrout (Cynoscion of the National Marine Fisheries Service, NOAA. Abstract--Stable isotope (SI) values of carbon (13C) and nitrogen patterns of enrichment in fish caught from coastal to off- shore sites and as a function of fish size

  19. Boron isotope application for tracing sources of contamination in groundwater.

    E-Print Network [OSTI]

    Kasher, Roni

    Boron isotope application for tracing sources of contamination in groundwater. Abstract: Boron isotope composition and concentration of sewage effluent and pristine and contaminated groundwater from sodium perborate as a bleaching agent in detergents, leads to an enrichment of boron in wastewaters

  20. Lithium Isotope History of Cenozoic Seawater: Changes in Silicate Weathering

    E-Print Network [OSTI]

    Paytan, Adina

    Lithium Isotope History of Cenozoic Seawater: Changes in Silicate Weathering and Reverse Weathering 70 Ma · Overview of the Marine Lithium Cycle · Analytical Challenges · 68 Million Year Seawater Lithium Isotope Record (Forams) · Interpretation Standard: NIST L-SVEC Li (SRM 8545) #12;100 Ma Climate

  1. Packed bed reactor for photochemical sup 196 Hg isotope separation

    SciTech Connect (OSTI)

    Grossman, M.W.; Speer, R.

    1992-03-03T23:59:59.000Z

    This patent describes a photochemical reactor useful for the isotopic enrichment of a predetermined isotope of mercury comprising a reactor cell and a monoisotopic light source It comprises: a plurality of transparent, straight reactor cell tubes disposed axially within the internal volume of the reactor cell to increase the surface area thereof for production deposition.

  2. RADIOGENIC ISOTOPES: TRACERS OF PAST OCEAN CIRCULATION AND EROSIONAL INPUT

    E-Print Network [OSTI]

    Jellinek, Mark

    of Earth Sciences Institute for Isotope Geology and Mineral Resources Eidgeno¨ssische Technische Hochschule the global mixing time of the ocean (Nd, Pb, Hf, and, in addition, Be). Their isotopic composition global ocean circulation system is largely driven by the sinking of cold, saline (and therefore dense

  3. atmospheric carbon isotope: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    atmospheric carbon isotope First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Carbon isotope...

  4. aves carbon isotopes: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    aves carbon isotopes First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 1, 393412, 2004 Carbon isotope...

  5. Nitrogen isotope effects on glutamate decarboxylase from Escherichia coli

    SciTech Connect (OSTI)

    Abell, L.M.; O'Leary, M.H.

    1988-05-03T23:59:59.000Z

    The nitrogen isotope effect on the decarboxylation of glutamic acid by glutamate decarboxylase from Escherichia coli has been measured by comparison of the isotopic composition of the amino nitrogen of the product ..gamma..-aminobutyric acid isolated after 10-20% reaction with that of the starting glutamic acid. At pH 4.7, 37 /sup 0/C, the isotope effect is k/sup 14//k/sup 15/ = 0.9855 +/- 0.0006 when compared to unprotonated glutamic acid. Interpretation of this result requires knowledge of the equilibrium nitrogen isotope effect for Schiff base formation. This equilibrium isotope effect is K/sup 14//K/sup 15/ - 0.9824 for the formation of the unprotonated Schiff base between unprotonated valine and salicylaldehyde. Analysis of the nitrogen isotope effect on decarboxylation of glutamic acid and of the previously measured carbon isotope effect on this same reaction shows that decarboxylation and Schiff base formation are jointly rate limiting. The enzyme-bound Schiff base between glutamate and pyridoxal 5'-phosphate partitions approximately 2:1 between decarboxylation and return to the starting state. The nitrogen isotope effect also reveals that the Schiff base nitrogen is protonated in this intermediate.

  6. Top quark mass measurements

    SciTech Connect (OSTI)

    Hill, Christopher S.; /UC, Santa Barbara

    2004-12-01T23:59:59.000Z

    The top quark, with its extraordinarily large mass (nearly that of a gold atom), plays a significant role in the phenomenology of EWSB in the Standard Model. In particular, the top quark mass when combined with the W mass constrains the mass of the as yet unobserved Higgs boson. Thus, a precise determination of the mass of the top quark is a principal goal of the CDF and D0 experiments. With the data collected thus far in Runs 1 and 2 of the Tevatron, CDF and D0 have measured the top quark mass in both the lepton+jets and dilepton decay channels using a variety of complementary experimental techniques. The author presents an overview of the most recent of the measurements.

  7. MASS MEASUREMENT UNCERTAINTY FOR PLUTONIUM ALIQUOTS ASSAYED BY CONTROLLED-POTENTIAL COULOMETRY

    SciTech Connect (OSTI)

    Holland, M.; Cordaro, J.

    2009-03-18T23:59:59.000Z

    Minimizing plutonium measurement uncertainty is essential to nuclear material control and international safeguards. In 2005, the International Organization for Standardization (ISO) published ISO 12183 'Controlled-potential coulometric assay of plutonium', 2nd edition. ISO 12183:2005 recommends a target of {+-}0.01% for the mass of original sample in the aliquot because it is a critical assay variable. Mass measurements in radiological containment were evaluated and uncertainties estimated. The uncertainty estimate for the mass measurement also includes uncertainty in correcting for buoyancy effects from air acting as a fluid and from decreased pressure of heated air from the specific heat of the plutonium isotopes.

  8. Process for recovery of daughter isotopes from a source material

    DOE Patents [OSTI]

    Tranter, Troy J.; Todd, Terry A.; Lewis, Leroy C.; Henscheid, Joseph P.

    2005-10-04T23:59:59.000Z

    The invention includes a method of separating isotopes from a mixture containing at least two isotopes in a solution. A first isotope is precipitated and is collected from the solution. A daughter isotope is generated and collected from the first isotope. The invention includes a method of producing an actinium-225/bismuth-213 product from a material containing thorium-229 and thorium-232. A solution is formed containing nitric acid and the material and iodate is added to form a thorium iodate precipitate. A supernatant is separated from the thorium iodate precipitate and a second volume of nitric acid is added to the precipitate. The precipitate is stored and a decay product comprising actinium-225 and bismuth-213 is generated in the second volume of nitric acid which is then separated from the thorium iodate precipitate, filtered, and treated using at least one chromatographic procedure. The invention also includes a system for producing an actinium-225/bismuth-213 product.

  9. A proposed standard on medical isotope production in fission reactors

    SciTech Connect (OSTI)

    Schenter, R. E. [Smart Bullets Inc., 2521 SW Luradel Street, Portland, OR 97219 (United States); Brown, G. J. [Ozarks Medical Center, Cancer Treatment Center, Shaw Medical Building, 1111 Kentucky Avenue, West Plains, MO 65775 (United States); Holden, C. S. [Thorenco LLC, 369 Pine Street, San Francisco, CA 94104 (United States)

    2006-07-01T23:59:59.000Z

    Authors Robert E. Sehenter, Garry Brown and Charles S. Holden argue that a Standard for 'Medical Isotope Production' is needed. Medical isotopes are becoming major components of application for the diagnosis and treatment of all the major diseases including all forms of cancer, heart disease, arthritis, Alzheimer's, among others. Current nuclear data to perform calculations is incomplete, dated or imprecise or otherwise flawed for many isotopes that could have significant applications in medicine. Improved data files will assist computational analyses to design means and methods for improved isotope production techniques in the fission reactor systems. Initial focus of the Standard is expected to be on neutron cross section and branching data for both fast and thermal reactor systems. Evaluated and reviewed tables giving thermal capture cross sections and resonance integrals for the major target and product medical isotopes would be the expected 'first start' for the 'Standard Working Group'. (authors)

  10. $\\beta$-decay of key titanium isotopes in stellar environment

    E-Print Network [OSTI]

    Nabi, Jameel-Un; 10.1142/S0218301311018174

    2011-01-01T23:59:59.000Z

    Amongst iron regime nuclei, $\\beta$-decay rates on titanium isotopes are considered to be important during the late phases of evolution of massive stars. The key $\\beta$-decay isotopes during presupernova evolution were searched from available literature and a microscopic calculation of the decay rates were performed using the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory. As per earlier simulation results electron capture and $\\beta$-decay on certain isotopes of titanium are considered to be important for the presupernova evolution of massive stars. Earlier the stellar electron capture rates and neutrino energy loss rates due to relevant titanium isotopes were presented. In this paper we finally present the $\\beta$-decay rates of key titanium isotopes in stellar environment. The results are also compared against previous calculations. The pn-QRPA $\\beta$-decay rates are bigger at high stellar temperatures and smaller at high stellar densities compared to the large scale shell model...

  11. Global Security, Medical Isotopes, and Nuclear Science

    SciTech Connect (OSTI)

    Ahle, L E

    2007-09-17T23:59:59.000Z

    Over the past century basic nuclear science research has led to the use of radioactive isotopes into a wide variety of applications that touch our lives everyday. Some are obvious, such as isotopes for medical diagnostics and treatment. Others are less so, such as National/Global security issues. And some we take for granted, like the small amount of 241Am that is in every smoke detector. At the beginning of this century, we are in a position where the prevalence and importance of some applications of nuclear science are pushing the basic nuclear science community for improved models and nuclear data. Yet, at the same time, the push by the basic nuclear science community to study nuclei that are farther and farther away from stability also offer new opportunities for many applications. This talk will look at several global security applications of nuclear science, summarizing current R&D and need for improved nuclear data It will also look at how applications of nuclear science, such as to medicine, will benefit from the push for more and more powerful radioactive ion beam facilities.

  12. MassMass transfer andtransfer and MassMass transfer andtransfer and

    E-Print Network [OSTI]

    Zevenhoven, Ron

    Heat conductivity T'1 Heat flux h" (W/m2), local and overall heat transfer coeffients h1 Heat transfer coefficientcoefficient /1/1 Mass flow species A:interface a p A = A mol/s M f1 (L) 2 (G) Mass transfer rate per area: A = A/a = "A mol/(m2·s) 1 (L) 2 (G) xi C1.i M t f ffi i t k x C y 1.i AA !!! Mass transfer coefficients

  13. Mass and Heat Recovery

    E-Print Network [OSTI]

    Hindawai, S. M.

    2010-01-01T23:59:59.000Z

    - 1 - MASS AND HEAT RECOVERY SYSTEM SALAH MAHMOUD HINDAWI DIRECTOR HINDAWI FOR ENGINEERING SERVICES & CONTRACTING NEW DAMIETTA , EGYPT ABSTRACT : In the last few years heat recovery was under spot . and in air conditioning fields... ) as a heat recovery . and I use the water as a mass recovery . The source of mass and heat recovery is the condensate water which we were dispose and connect it to the drain lines . THE BENEFIT OF THIS SYSTEM ARE : 1) Using the heat energy from...

  14. Nuclear Masses in Astrophysics

    E-Print Network [OSTI]

    Christine Weber; Klaus Blaum; Hendrik Schatz

    2008-12-09T23:59:59.000Z

    Among all nuclear ground-state properties, atomic masses are highly specific for each particular combination of N and Z and the data obtained apply to a variety of physics topics. One of the most crucial questions to be addressed in mass spectrometry of unstable radionuclides is the one of understanding the processes of element formation in the Universe. To this end, accurate atomic mass values of a large number of exotic nuclei participating in nucleosynthesis are among the key input data in large-scale reaction network calculations. In this paper, a review on the latest achievements in mass spectrometry for nuclear astrophysics is given.

  15. Multiple mass solvers

    E-Print Network [OSTI]

    B. Jegerlehner

    1997-08-29T23:59:59.000Z

    We present a general method to construct multiple mass solvers from standard algorithms. As an example, the BiCGstab-M algorithm is derived.

  16. EMSL - Mass Spectrometer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MS) with high mass resolution (m&61636;m100,000). Solvent mixtures of acetonitrilewater and acetonitriletoluene were used to extract and ionize polar and non-polar...

  17. A METHODOLOGY FOR DETERMINING THE DOSE RATE FOR BOUNDING MASS LIMITS IN A 9977 PACKAGING

    SciTech Connect (OSTI)

    Abramczyk, G.; Bellamy, S.; Nathan, S.; Loftin, B.

    2012-05-24T23:59:59.000Z

    The Small Gram Quantity (SGQ) concept is based on the understanding that the hazards associated with the shipment of a radioactive material are directly proportional to its mass. This study describes a methodology that estimates the acceptable masses for several neutron and gamma emitting isotopes that can be shipped in a 9977 Package compliant with the Title 10 of the Code of Federal Regulations, Part 71 (10CFR71) external radiation level limits. 10CFR71.33 states that a shipping application identifies the radioactive and fissile materials at their maximum quantity and provides an evaluation demonstrating compliance with the external radiation standards. Since rather small amounts of some isotopes emit sufficiently strong radiation to produce a large external dose rate, quantifying of the dose rate for a proposed content is a challenging issue for the SGQ approach. It is essential to quantify external radiation levels from several common gamma and neutron sources that can be safely placed in a specific packaging, to ensure compliance with federal regulations. A methodology was established for determining the dose rate for bounding mass limits for a set of isotopes in the Model 9977 Shipping Package. Calculations were performed to estimate external radiation levels using the MCNP radiation transport code to develop a set of response multipliers (Green's functions) for 'dose per source particle' for each neutron and photon spectral group. The source spectrum from one gram of each isotope was folded with the response multipliers to generate the dose rate per gram of each isotope in the 9977 shipping package and its associated shielded containers. The maximum amount of a single isotope that could be shipped within the regulatory limits for dose rate at the surface was determined. For a package containing a mixture of isotopes, the acceptability for shipment can be determined by a sum of fractions approach. Furthermore, the results of this analysis can be easily extended to additional radioisotopes by simply evaluating the neutron and/or photon spectra of those isotopes and folding the spectral data with the Green's functions provided.

  18. New species of Mycosphaerella occurring on Eucalyptus leaves in Indonesia and Africa

    E-Print Network [OSTI]

    781 New species of Mycosphaerella occurring on Eucalyptus leaves in Indonesia and Africa P.W. Crous and M.J. Wingfield Ahstract:Although Africa and Indonesia have not been particularly well surveyed Eucalyptus leaves from Indonesia. The former species is of particular interest, because its anamorph

  19. Spike-timing dependent plasticity Spike order determines if potentiation or depression occurs [Poo98].

    E-Print Network [OSTI]

    Boahen, Kwabena

    in dendritic spines of pyramidal cells (L2/3, somatosensory cortex) does not predict the occurence of LTP or LTD. In this imaging experiment, the change relative to baseline of a Ca-sensitive green flourescent dye (DG) was normalized by a Ca-insensitive red flourescent dye (R) to account for differences

  20. Catastrophic Collapse Can Occur without Early Warning: Examples of Silent Catastrophes in Structured Ecological

    E-Print Network [OSTI]

    Roos, André M. de

    of the eigenvectors of the system. Our results demonstrate that claims on the universality of early warning signalsCatastrophic Collapse Can Occur without Early Warning: Examples of Silent Catastrophes Abstract Catastrophic and sudden collapses of ecosystems are sometimes preceded by early warning signals

  1. Mineralization of Decalcified Bone Occurs Under Cell Culture Conditions and Requires Bovine Serum But Not Cells

    E-Print Network [OSTI]

    Price, Paul A.

    Mineralization of Decalcified Bone Occurs Under Cell Culture Conditions and Requires Bovine Serum mineralization in the absence of cells. For this model, we utilized EDTA- decalcified new-born rat tibias with the cartilaginous ends intact, allowing us to visually determine the spec- ificity of mineralization within the bone

  2. C6H5Br+ f C6H5 + + Br Occurs via Orbiting Transition State

    E-Print Network [OSTI]

    Kim, Myung Soo

    -analyzed ion kinetic energy spectrometry. The rate constant and kinetic energy release distribution have been at high internal energy. The completely loose transition state model, namely the reaction occurring via compared with theoretical calculations. The rate-energy data available over 6 orders of magnitude in time

  3. Roles of Naturally Occurring Bacteria in Controlling Iodine-129 Mobility in Subsurface Soils

    E-Print Network [OSTI]

    Li, Hsiu-Ping

    2012-10-19T23:59:59.000Z

    - to reactive intermediates. The aim of this study was to determine the influence of naturally occurring aerobic bacteria isolated from an 129I contaminated aquifer (F-area of the Savannah River Site, SC) on I- oxidation and OI formation. It was demonstrated...

  4. Tuesday, 31 July, 2012 Rapid radiation belt losses occurring during high speed solar wind stream1

    E-Print Network [OSTI]

    Otago, University of

    Tuesday, 31 July, 2012 1 Rapid radiation belt losses occurring during high speed solar wind stream1 Raita11 Sodankylä Geophysical Observatory, University of Oulu, Sodankylä, Finland12 Abstract. Recent geomagnetic disturbances triggered by the arrival of a Solar14 Wind Stream Interface (SWSI). In the current

  5. Obesity is defined as an excess accumulation of adipose tissue. It occurs in mammalian

    E-Print Network [OSTI]

    Cai, Long

    Obesity is defined as an excess accumulation of adipose tissue. It occurs in mammalian species when, obesity is now at epidemic proportions in the developed world1 , as well as in many developing countries2 . The links between obesity, type 2 diabetes and cardiovascular diseases have long been appreciated. However

  6. 2 Bainitic Ferrite The growth of pearlite occurs at a common transformation front with the

    E-Print Network [OSTI]

    Cambridge, University of

    2 Bainitic Ferrite The growth of pearlite occurs at a common transformation front with the austenite. The growth of the ferrite and cementite phases is coupled and their compositions are complementary since the carbon which cannot be accommodated by the ferrite is incorporated into the cementite

  7. Endophytic and canker-associated Botryosphaeriaceae occurring on non-native Eucalyptus and native Myrtaceae

    E-Print Network [OSTI]

    Endophytic and canker-associated Botryosphaeriaceae occurring on non-native Eucalyptus and native to identify the Botryosphaeriaceae species present as endophytes or associated with cankers in both introduced is a very diverse group of fungi that includes endophytes and plant pathogens of trees and plants (Alves et

  8. Jet-like circulations occur in the `simple' geometries of gas planets and Earth's

    E-Print Network [OSTI]

    #12;Jet-like circulations occur in the `simple' geometries of gas planets and Earth's liquid The Jet Stream Conundrum Baldwin, Rhines, Huang & McIntyre, Nature 2007 #12;For Earth's oceans, density and jets Tracks of fast sea- surface drifters, Jakobsen 1994 #12;channels & atmospheres: PV stirring

  9. Movement of oxygen from the atmosphere to the mitochondria occurs via several convective and diffusive steps

    E-Print Network [OSTI]

    Bennett, Albert F.

    4111 Movement of oxygen from the atmosphere to the mitochondria occurs via several convective and diffusive steps (Weibel et al., 1981). In mammals, maximal rate of oxygen consumption (VOmax) is not limited by any one step of the oxygen cascade; rather limitations to VOmax are distributed across all steps

  10. Fuel-related accidents occur across the country at the rate of more than one per

    E-Print Network [OSTI]

    Minnesota, University of

    Fuel-related accidents occur across the country at the rate of more than one per week. Fuel exhaustion, fuel starvation, or the failure to switch tanks at the correct time caused 120 accidents in 2002, these and other problems can be avoided with proper fueling procedures. RESPONSIBILITY STARTS WITH THE AIRPORT

  11. "Climate change is sure to occur in some form." The study of climate impacts notes

    E-Print Network [OSTI]

    "Climate change is sure to occur in some form." 1 #12;The study of climate impacts notes how scientists generally agree that humans are changing the climate, and that if we continue pumping carbon we learn from past climate variations? How can we best adapt to climate change? This report attempts

  12. Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species

    E-Print Network [OSTI]

    Jackson, Robert B.

    Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species: 10.1111/j.1399-3054.2006.00644.x Previous studies indicate that conifers are vulnerable to cavitation cavitation, along with wood density, conduit reinforcement, trac- heid diameter, and hydraulic conductivity

  13. Recent activities for ?-decay half-lives and ?-delayed neutron emission of very neutron-rich isotopes

    SciTech Connect (OSTI)

    Dillmann, Iris [TRIUMF, Vancouver BC, V6T 2A3, Canada and GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Abriola, Daniel [Laboratorio Tandar, Comisión Nacional de Energía Atómica, B1650KINA, San Martín, Buenos Aires (Argentina); Singh, Balraj [Department of Physics and Astronomy, McMaster University, Hamilton ON, L8S 4M1 (Canada)

    2014-05-02T23:59:59.000Z

    Beta-delayed neutron (?n) emitters play an important, two-fold role in the stellar nucleosynthesis of heavy elements in the 'rapid neutron-capture process' (r process). On one hand they lead to a detour of the material ?-decaying back to stability. On the other hand, the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. A large fraction of the isotopes inside the r-process reaction path are not yet experimentally accessible and are located in the (experimental) 'Terra Incognita'. With the next generation of fragmentation and ISOL facilities presently being built or already in operation, one of the main motivation of all projects is the investigation of these very neutron-rich isotopes. A short overview of one of the planned programs to measure ?n-emitters at the limits of the presently know isotopes, the BRIKEN campaign (Beta delayed neutron emission measurements at RIKEN) will be given. Presently, about 600 ?-delayed one-neutron emitters are accessible, but only for a third of them experimental data are available. Reaching more neutron-rich isotopes means also that multiple neutron-emission becomes the dominant decay mechanism. About 460 ?-delayed two-, three-or four-neutron emitters are identified up to now but for only 30 of them experimental data about the neutron branching ratios are available, most of them in the light mass region below A=30. The International Atomic and Energy Agency (IAEA) has identified the urgency and picked up this topic recently in a 'Coordinated Research Project' on a 'Reference Database for Beta-Delayed Neutron Emission Data'. This project will review, compile, and evaluate the existing data for neutron-branching ratios and half-lives of ?-delayed neutron emitters and help to ensure a reliable database for the future discoveries of new isotopes and help to constrain astrophysical and theoretical models.

  14. Isospin effects on the mass dependence of balance energy

    E-Print Network [OSTI]

    Sakshi Gautam; Aman D. Sood

    2010-07-09T23:59:59.000Z

    We study the effect of isospin degree of freedom on balance energy throughout the mass range between 50 and 350 for two sets of isotopic systems with N/Z = 1.16 and 1.33 as well as isobaric systems with N/Z = 1.0 and 1.4. Our findings indicate that different values of balance energy for two isobaric systems may be mainly due to the Coulomb repulsion. We also demonstrate clearly the dominance of Coulomb repulsion over symmetry energy.

  15. Isospin effects on the mass dependence of the balance energy

    SciTech Connect (OSTI)

    Gautam, Sakshi [Department of Physics, Panjab University, Chandigarh 160 014 (India); Sood, Aman D. [SUBATECH, Laboratoire de Physique Subatomique et des Technologies Associees, Universite de Nantes, IN2P3/CNRS, EMN 4 rue Alfred Kastler, F-44072 Nantes (France)

    2010-07-15T23:59:59.000Z

    We study the effect of isospin degree of freedom on balance energy throughout the mass range between 50 and 350 for two sets of isotopic systems with N/A= 0.54 and 0.57 as well as isobaric systems with N/A= 0.5 and 0.58. Our findings indicate that different values of balance energy for two isobaric systems may be mainly due to the Coulomb repulsion. We also demonstrate clearly the dominance of Coulomb repulsion over symmetry energy.

  16. Fission Yield Measurements by Inductively Coupled Plasma Mass-Spectrometry

    SciTech Connect (OSTI)

    Irina Glagolenko; Bruce Hilton; Jeffrey Giglio; Daniel Cummings; Karl Grimm; Richard McKnight

    2009-11-01T23:59:59.000Z

    Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. Unfortunately, the accuracy of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry.

  17. Midcontinent rift volcanism in the Lake Superior region: Sr, Nd, and Pb isotopic evidence for a mantle plume origin

    SciTech Connect (OSTI)

    Nicholson, S.W. (Geological Survey, Reston, VA (USA) Univ. of Minnesota, MN (USA)); Shirey, S.B. (Carnegie Institution of Washington, DC (USA))

    1990-07-10T23:59:59.000Z

    Between 1091 and 1098 Ma, most of a 15- to 20-km thickness of dominantly tholeiitic basalt erupted in the Midcontinent Rift System of the Lake Superior region, North American. The Portage Lake Volcanics in Michigan, which are the youngest MRS flood basalts, fall into distinctly high- and low-TiO{sub 2} types having different liquid lines of descent. Incompatible trace elements in both types of tholeiites are enriched compared to depleted or primitive mantle (La/Yb = 4.3-5.3; Th/Ta = 2.12-2.16; Zr/Y = 4.3-4.4), and both basalt types are isotopically indistinguishable. Sr, Nd, and Pb isotopic compositions of the Portage Lake tholeiites have {sup 87}Sr/{sup 86}Sr{sub i} {approx}0.7038, {epsilon}{sub Nd(1095 Ma)} {approx}0 {plus minus} 2, and {mu}{sub 1} {approx}8.2. Model ages with respect to a depleted mantle source (T{sub DM}) average about 1950-2100 Ma. Portage Lake rhyolits fall into two groups. Type I rhyolites have Nd and Pb isotopic characteristics ({epsilon}{sub Nd(1095 Ma)} {approx}0 to {minus}4.7; {mu}{sub 1} {approx}8.2-7.8) consistent with contamination of tholeiitic rocks by 5-10% Archean crust. The one type II rhyolite analyzed has Nd and Pb isotopic compositions ({epsilon}{sub Nd(1095 Ma)} {approx}{minus}13 to {minus}16; {mu}{sub 1} {approx}7.6-7.7) which are consistent with partial melting of Archean crust. Early Proterozoic crust was not a major contaminant of MRS rocks in the Lake Superior region. Most reported Nd and Pb isotopic compositions of MRS tholeiites from the main stage of volcanism in the Lake Superior region and of the Duluth Complex are comparable to the Nd and Pb isotopic data for Portage lake tholeiites. The isotopic enrichment of the MRS source compared to depleted mantle is striking and must have occurred at least 700 m.y. before 1100 Ma.

  18. Lead Isotopic Variations of the Pacific and Implications for Paleogene Water Mass Composition

    E-Print Network [OSTI]

    Subt, Cristina

    2013-11-13T23:59:59.000Z

    sincerest thanks to my advisor and committee chair, Dr. Debbie Thomas, who has never failed to provide expert guidance and valuable advice. I would also thank my committee members, Drs. Franco Marcantonio and Robert Korty, as well as Dr. Brent Miller...;#19;Ý #28;#19;Ý #28;#19;Ý CJ01 CLD01 CB12 Marshalls Nova Tasman MP3D07 MDD53 CXD55 192 323 463 464 596 883 192 883 64 463 596 323 18.7-19.5 15.53-15.68 38.2- 39.2 17.9-19.4 15.52-15.68 38.3-39.1 17.9-18.7 15.4-15.7 37.7-38.9 19.5-21 15.6-15.75 38...

  19. Isotopic mass-dependence of noble gas diffusion coefficients in water

    E-Print Network [OSTI]

    Bourg, I.C.; Sposito, G.

    2008-01-01T23:59:59.000Z

    extended simple point charge (SPC/E) model of Berendsen ete and q H = 0.4238 e)] the SPC/E model predicts the self-Hura et al. , 2003). On the SPC/E model, short-range non-

  20. A Mass Spectrometry Study of Isotope Separation in the Laser Plume

    E-Print Network [OSTI]

    Suen, Timothy Wu

    2012-01-01T23:59:59.000Z

    Gamma Ray Spectrometry . . . . . . . . . . . . . . . . . . .29, 30] Gamma Ray Spectrometry Gamma ray spectrometry willare measured by gamma spectrometry and compared to model

  1. A Mass Spectrometry Study of Isotope Separation in the Laser Plume

    E-Print Network [OSTI]

    Suen, Timothy Wu

    2012-01-01T23:59:59.000Z

    Enriched Uranium Particles”, Analytical Chemistry 71, 2616 (Uranium Oxide Microparticles: A Nuclear Forensic Diagnostic”, Analytical Chemistry

  2. A Mass Spectrometry Study of Isotope Separation in the Laser Plume

    E-Print Network [OSTI]

    Suen, Timothy Wu

    2012-01-01T23:59:59.000Z

    quantities of natural or depleted uranium [8]. Plutonium, on235 U abundance in depleted uranium. The sample was ablatedsuch as 235 U in depleted uranium [64] or short-lived

  3. New insights into Archean sulfur cycle from mass-independent sulfur isotope records from the

    E-Print Network [OSTI]

    of Archean sulfur reservoirs and to trace pathways in the Archean sulfur cycle. Our data are explained S/33 S/32 S) for sulfide sulfur in shale and carbonate lithofacies from the Hamersley Basin, Western of the lower Mount McRae Shale (V2.5 Ga). Likewise, sulfide sulfur analyses of the Jeerinah Formation (V2.7 Ga

  4. mass communication advertising &

    E-Print Network [OSTI]

    Finzi, Adrien

    mass communication advertising & public relations introduction. Graduate programs in the Department of Mass Communication, Advertising, and Public Relations provide an entry to a wide spectrum of careers in the communication industry. Classes, internships, site visits, and presentations by top professionals offer students

  5. The Origins of Mass

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-07T23:59:59.000Z

    The Higgs boson was discovered in July of 2012 and is generally understood to be the origin of mass. While those statements are true, they are incomplete. It turns out that the Higgs boson is responsible for only about 2% of the mass of ordinary matter. In this dramatic new video, Dr. Don Lincoln of Fermilab tells us the rest of the story.

  6. The Origins of Mass

    SciTech Connect (OSTI)

    Lincoln, Don

    2014-07-30T23:59:59.000Z

    The Higgs boson was discovered in July of 2012 and is generally understood to be the origin of mass. While those statements are true, they are incomplete. It turns out that the Higgs boson is responsible for only about 2% of the mass of ordinary matter. In this dramatic new video, Dr. Don Lincoln of Fermilab tells us the rest of the story.

  7. Isotope exchange kinetics in metal hydrides I : TPLUG model.

    SciTech Connect (OSTI)

    Larson, Rich; James, Scott Carlton; Nilson, Robert H.

    2011-05-01T23:59:59.000Z

    A one-dimensional isobaric reactor model is used to simulate hydrogen isotope exchange processes taking place during flow through a powdered palladium bed. This simple model is designed to serve primarily as a platform for the initial development of detailed chemical mechanisms that can then be refined with the aid of more complex reactor descriptions. The one-dimensional model is based on the Sandia in-house code TPLUG, which solves a transient set of governing equations including an overall mass balance for the gas phase, material balances for all of the gas-phase and surface species, and an ideal gas equation of state. An energy equation can also be solved if thermodynamic properties for all of the species involved are known. The code is coupled with the Chemkin package to facilitate the incorporation of arbitrary multistep reaction mechanisms into the simulations. This capability is used here to test and optimize a basic mechanism describing the surface chemistry at or near the interface between the gas phase and a palladium particle. The mechanism includes reversible dissociative adsorptions of the three gas-phase species on the particle surface as well as atomic migrations between the surface and the bulk. The migration steps are more general than those used previously in that they do not require simultaneous movement of two atoms in opposite directions; this makes possible the creation and destruction of bulk vacancies and thus allows the model to account for variations in the bulk stoichiometry with isotopic composition. The optimization code APPSPACK is used to adjust the mass-action rate constants so as to achieve the best possible fit to a given set of experimental data, subject to a set of rigorous thermodynamic constraints. When data for nearly isothermal and isobaric deuterium-to-hydrogen (D {yields} H) and hydrogen-to-deuterium (H {yields} D) exchanges are fitted simultaneously, results for the former are excellent, while those for the latter show pronounced deviations at long times. These discrepancies can be overcome by postulating the presence of a surface poison such as carbon monoxide, but this explanation is highly speculative. When the method is applied to D {yields} H exchanges intentionally poisoned by known amounts of CO, the fitting results are noticeably degraded from those for the nominally CO-free system but are still tolerable. When TPLUG is used to simulate a blowdown-type experiment, which is characterized by large and rapid changes in both pressure and temperature, discrepancies are even more apparent. Thus, it can be concluded that the best use of TPLUG is not in simulating realistic exchange scenarios, but in extracting preliminary estimates for the kinetic parameters from experiments in which variations in temperature and pressure are intentionally minimized.

  8. Secondary Ion Mass Spectrometry of Environmental Aerosols

    SciTech Connect (OSTI)

    Gaspar, Daniel J.; Cliff, John B.

    2010-08-01T23:59:59.000Z

    Atmospheric particles influence many aspects of climate, air quality and human health. Understanding the composition, chemistry and behavior of atmospheric aerosols is a key remaining challenge in improving climate models. Furthermore, particles may be traced back to a particular source based on composition, stable isotope ratios, or the presence of particular surface chemistries. Finally, the characterization of atmospheric particles in the workplace plays an important role in understanding the potential for exposure and environmental and human health effects to engineered and natural nanoscale particles. Secondary ion mass spectrometry (SIMS) is a useful tool in determining any of several aspects of the structure, composition and chemistry of these particles. Often used in conjunction with other surface analysis and electron microscopy methods, SIMS has been used to determine or confirm reactions on and in particles, the presence of particular organic species on the surface of atmospheric aerosols and several other interesting and relevant findings. Various versions of SIMS instruments – dynamic SIMS, time of flight secondary ion mass spectrometry or TOF-SIMS, nanoSIMS – have been used to determine specific aspects of aerosol structure and chemistry. This article describes the strengths of each type of SIMS instrument in the characterization of aerosols, along with guidance on sample preparation, specific characterization specific to the particular information sought in the analysis. Examples and guidance are given for each type of SIMS analysis.

  9. Temperature dependence of carbon isotope fractionation in CAM plants

    SciTech Connect (OSTI)

    Deleens, E.; Treichel, I.; O'Leary, M.H.

    1985-09-01T23:59:59.000Z

    The carbon isotope fractionation associated with nocturnal malic acid synthesis in Kalanchoe daigremontiana and Bryophyllum tubiflorum was calculated from the isotopic composition of carbon-4 of malic acid, after appropriate corrections. In the lowest temperature treatment (17/sup 0/C nights, 23/sup 0/C days), the isotope fractionation for both plants is -4% per thousand (that is, malate is enriched in /sup 13/C relative to the atmosphere). For K. daigremontiana, the isotope fractionation decreases with increasing temperature, becoming approximately 0% per thousand at 27/sup 0/C/33/sup 0/C. Detailed analysis of temperature effects on the isotope fractionation indicates that stomatal aperture decreases with increasing temperature and carboxylation capacity increases. For B. tubiflorum, the temperature dependence of the isotope fractionation is smaller and is principally attributed to the normal temperature dependences of the rates of diffusion and carboxylation steps. The small change in the isotopic composition of remaining malic acid in both species which is observed during deacidification indicates that malate release, rather than decarboxylation, is rate limiting in the deacidification process. 28 references, 1 figure, 4 tables.

  10. Disk Accretion Onto High-Mass Planets

    E-Print Network [OSTI]

    S. H. Lubow; M. Seibert; P. Artymowicz

    1999-10-21T23:59:59.000Z

    We analyze the nonlinear, two-dimensional response of a gaseous, viscous protoplanetary disk to the presence of a planet of one Jupiter mass (1 M_J) and greater that orbits a 1 solar mass star by using the ZEUS hydrodynamics code with high resolution near the planet's Roche lobe. The planet is assumed to be in a circular orbit about the central star and is not allowed to migrate. A gap is formed about the orbit of the planet, but there is a nonaxisymmetric flow through the gap and onto the planet. The gap partitions the disk into an inner (outer) disk that extends inside (outside) the planet's orbit. For a 1 M_J planet and typical disk parameters, the accretion through the gap onto the planet is highly efficient. For typical disk parameters, the mass doubling time scale is less than 10^5 years, considerably shorter than the disk lifetime. Following shocks near the L1 and L2 Lagrange points, disk material enters the Roche lobe in the form of two gas streams. Shocks occur within the Roche lobe as the gas streams collide, and shocks lead to rapid inflow towards the planet within much of planet's Roche lobe. Shocks also propagate in the inner and outer disks that orbit the star. For higher mass planets (of order 6 M_J), the flow rate onto the planet is considerably reduced, which suggests an upper mass limit to planets in the range of 10 M_J. This rate reduction is related to the fact that the gap width increases relative to the Roche (Hill sphere) radius with increasing planetary mass. The flow in the gap affects planetary migration. For the 1 M_J planet case, mass can penetrate from the outer disk to the inner disk, so that the inner disk is not depleted. The results suggest that most of the mass in gas giant planets is acquired by flows through gaps.

  11. Microscopic description of fission in Uranium isotopes with the Gogny energy density functional

    E-Print Network [OSTI]

    R. Rodriguez-Guzman; L. M. Robledo

    2014-05-25T23:59:59.000Z

    The most recent parametrizations D1S, D1N and D1M of the Gogny energy density functional are used to describe fission in the isotopes $^{232-280}$ U. Fission paths, collective masses and zero point quantum corrections, obtained within the constrained Hartree-Fock-Bogoliubov approximation, are used to compute the systematics of the spontaneous fission half-lives $t_\\mathrm{SF}$, the masses and charges of the fission fragments as well as their intrinsic shapes. The Gogny-D1M parametrization has been benchmarked against available experimental data on inner and second barrier heights, excitation energies of the fission isomers and half-lives in a selected set of Pu, Cm, Cf, Fm, No, Rf, Sg, Hs and Fl nuclei. It is concluded that D1M represents a reasonable starting point to describe fission in heavy and superheavy nuclei. Special attention is also paid to understand the uncertainties in the predicted $t_\\mathrm{SF}$ values arising from the different building blocks entering the standard semi-classical Wentzel-Kramers-Brillouin formula. Although the uncertainties are large, the trend with mass or neutron numbers are well reproduced and therefore the theory still has predictive power. In this respect, it is also shown that modifications of a few per cent in the pairing strength can have a significant impact on the collective masses leading to uncertainties in the $t_\\mathrm{SF}$ values of several orders of magnitude.

  12. The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems

    E-Print Network [OSTI]

    The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems

  13. Assessment of shock effects on amphibole water contents and hydrogen isotope compositions: 2. Kaersutitic

    E-Print Network [OSTI]

    Stewart, Sarah T.

    to the experimental kaersutite compositions, means the measured hydrogen isotope enrichments are likely minima. The measured (minimum) levels of hydrogen isotope enrichment are relevant to the hydrogen isotope variabilityAssessment of shock effects on amphibole water contents and hydrogen isotope compositions: 2

  14. A coupled isotope tracer method to characterize input water to lakes

    E-Print Network [OSTI]

    Edwards, Thomas W.D.

    of input waters after accounting for the effects of secondary evaporative isotopic enrichment. As shownA coupled isotope tracer method to characterize input water to lakes Yi Yi a,*, Bronwyn E. Brock in revised form 7 November 2007; accepted 9 November 2007 KEYWORDS Water isotope tracers; Isotope hydrology

  15. ORIGINAL PAPER Crystal scale anatomy of a dying supervolcano: an isotope

    E-Print Network [OSTI]

    Bindeman, Ilya N.

    determined by ion microprobe, and sanidine Pb isotope ratios determined by laser ablation, to investigate

  16. Glaciation, aridification, and carbon sequestration in the Permo-Carboniferous: The isotopic record from low latitudes

    E-Print Network [OSTI]

    Grossman, Ethan L.

    Glaciation, aridification, and carbon sequestration in the Permo-Carboniferous: The isotopic record and carbon sequestration in the Late Paleozoic, we have compiled new and published oxygen and carbon isotopic Carboniferous Stable isotopes Carbon cycling Brachiopods To evaluate the isotopic record of climate change

  17. Scoping assessment on medical isotope production at the Fast Flux Test Facility

    SciTech Connect (OSTI)

    Scott, S.W.

    1997-08-29T23:59:59.000Z

    The Scoping Assessment addresses the need for medical isotope production and the capability of the Fast Flux Test Facility to provide such isotopes. Included in the discussion are types of isotopes used in radiopharmaceuticals, which types of cancers are targets, and in what way isotopes provide treatment and/or pain relief for patients.

  18. The influence of kinetics on the oxygen isotope composition of calcium carbonate

    E-Print Network [OSTI]

    Watkins, Jim

    The influence of kinetics on the oxygen isotope composition of calcium carbonate James M. Watkins a and calcium carbonate. Although oxygen isotope separation is expected on theoretical grounds, the temperature on equilibrium fractionation of oxygen isotopes between calcium carbonate and water. Equili- brium oxygen isotope

  19. Standard practice for the ion exchange separation of uranium and plutonium prior to isotopic analysis

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2008-01-01T23:59:59.000Z

    Standard practice for the ion exchange separation of uranium and plutonium prior to isotopic analysis

  20. Preservation of seawater Sr and Nd isotopes in fossil sh teeth: bad news and good news

    E-Print Network [OSTI]

    Martin, Ellen

    system, our Nd concentration data, combined with published isotopic and rare earth element data, suggest on the global seawater Sr isotope curve. For Sites 1090, 757, and 807 Sr isotopic values of the pore fluids Nd isotopic compositions from the time of deposition. Ã? 2004 Elsevier B.V. All rights reserved

  1. Giant Quadrupole-Resonance in Ni Isotopes

    E-Print Network [OSTI]

    Youngblood, David H.; Lui, YW; Garg, U.; Peterson, R. J.

    1992-01-01T23:59:59.000Z

    PHYSICAL REVIEW C VOLUME 45, NUMBER 5 MAY 1992 Giant quadrupole resonance in Ni isotopes D. H. Youngblood and Y.-%. Lui Texas A&M UniUersity, College Station, Texas 77843 U. Garg University of Notre Dame, South Bend, Indiana 46556 R. J...R )' 0.53 0.68 0.69 0.78 E2 EWSR (%) 58+12 76+14 78+14 90+16 Cp 0.80+0.04 0.84+0.04 0.82+0. 12 1.05+0. 10 2174 YOUNGBLOOD, LUI, GARG, AND PETERSON 45 1000 100 60Ni(n, n') E = 129 MeV 1 000 100 58Ni(n, n') 10 10 100 z' 1000 64Ni...

  2. Shell model description of Ge isotopes

    E-Print Network [OSTI]

    J. G. Hirsch; P. C. Srivastava

    2012-04-12T23:59:59.000Z

    A shell model study of the low energy region of the spectra in Ge isotopes for $38\\leq N\\leq 50$ is presented, analyzing the excitation energies, quadrupole moments, $B(E2)$ values and occupation numbers. The theoretical results have been compared with the available experimental data. The shell model calculations have been performed employing three different effective interactions and valence spaces.We have used two effective shell model interactions, JUN45 and jj44b, for the valence space $f_{5/2} \\, p \\,g_{9/2}$ without truncation. To include the proton subshell $f_{7/2}$ in valence space we have employed the $fpg$ effective interaction due to Sorlin {\\it et al.}, with $^{48}$Ca as a core and a truncation in the number of excited particles.

  3. Photonuclear Reaction Cross Sections for Gallium Isotopes

    E-Print Network [OSTI]

    Serkan Akkoyun; Tuncay Bayram

    2014-09-08T23:59:59.000Z

    The photon induced reactions which are named as photonuclear reactions have a great importance in many field of nuclear, radiation physics and related fields. Since we have planned to perform photonuclear reaction on gallium target with bremmstrahlung photons from clinical linear accelerator in the future, the cross-sections of neutron (photo-neutron ({\\gamma},xn)) and proton (photo-proton ({\\gamma},xn)) productions after photon activation have been calculated by using TALYS 1.2 computer code in this study. The target nucleus has been considered gallium which has two stable isotopes, 69Ga and 71Ga. According to the results, we have seen that the calculations are in harmony in the limited literature values. Furthermore, the pre-equilibrium and compound process contributions to the total cross-section have been investigated.

  4. Chemical and isotopic determination from complex spectra

    SciTech Connect (OSTI)

    Zardecki, A.; Strittmatter, R.B.

    1995-07-01T23:59:59.000Z

    Challenges for proliferation detection include remote, high- sensitivity detection of chemical effluents from suspect facilities and enhanced detection sensitivity for nuclear material. Both the identification of chemical effluents with lidar and enhanced nuclear material detection from radiation sensors involve determining constituents from complex spectra. In this paper, we extend techniques used to analyze time series to the analysis of spectral data. Pattern identification methods are applied to spectral data for domains where standard matrix inversion may not be suitable because of detection statistics. We use a feed-forward, back-propagation neural network in which the nodes of the input layer are fed with the observed spectral data. The nodes of the output layer contain the identification and concentration of the isotope or chemical effluent the sensor is to identify. We will discuss the neural network architecture, together with preliminary results obtained from the training process.

  5. Chiral three-nucleon forces and the evolution of correlations along the oxygen isotopic chain

    E-Print Network [OSTI]

    A. Cipollone; C. Barbieri; P. Navrátil

    2014-12-01T23:59:59.000Z

    The impact of three-nucleon forces (3NFs) along the oxygen chain is investigated for the spectral distribution for attachment and removal of a nucleon, spectroscopic factors and matter radii. We employ self-consistent Green's function (SCGF) theory which allows a comprehensive calculation of the single particle spectral function. For the closed subshell isotopes, $^{14}$O, $^{16}$O, $^{22}$O, $^{24}$O and $^{28}$O, we perform calculations with the Dyson-ADC(3) method. The remaining open shell isotopes are studied using the newly developed Gorkov-SCGF formalism up to second order. We produce plots for the full-fledged spectral distributions. The spectroscopic factors for the dominant quasiparticle peaks are found to depend very little on the leading order (NNLO) chiral 3NFs. The latters have small impact on the calculated matter radii, which, however are consistently obtained smaller than experiment. Similarly, single particle spectra tend to be diluted with respect to experiment. This effect might hinder, to some extent, the onset of correlations and screen the quenching of calculated spectroscopic factors. The most important effects of 3NFs is thus the fine tuning of the energies for the dominant quasiparticle states, which govern the shell evolution and the position of driplines. Although present chiral NNLO 3NFs interactions do reproduce the binding energies correctly in this mass region, the details of the nuclear wave function remain at odd with the experiment showing too small radii and a too dilute single particle spectrum, similar to what already pointed out for larger masses. This suggests a lack of repulsion in the present model of NN+3N interactions which is mildly apparent already for masses in the A=14--28 range.

  6. Direct analysis of samples by mass spectrometry: From elements to bio-molecules using laser ablation inductively couple plasma mass spectrometry and laser desorption/ionization mass spectrometry

    SciTech Connect (OSTI)

    Perdian, David C.

    2009-08-19T23:59:59.000Z

    Mass spectrometric methods that are able to analyze solid samples or biological materials with little or no sample preparation are invaluable to science as well as society. Fundamental research that has discovered experimental and instrumental parameters that inhibit fractionation effects that occur during the quantification of elemental species in solid samples by laser ablation inductively coupled plasma mass spectrometry is described. Research that determines the effectiveness of novel laser desorption/ionization mass spectrometric methods for the molecular analysis of biological tissues at atmospheric pressure and at high spatial resolution is also described. A spatial resolution is achieved that is able to analyze samples at the single cell level.

  7. Isotope and Nuclear Chemistry Division annual report, FY 1983

    SciTech Connect (OSTI)

    Heiken, J.H.; Lindberg, H.A. (eds.)

    1984-05-01T23:59:59.000Z

    This report describes progress in the major research and development programs carried out in FY 1983 by the Isotope and Nuclear Chemistry Division. It covers radiochemical diagnostics of weapons tests; weapons radiochemical diagnostics research and development; other unclassified weapons research; stable and radioactive isotope production, separation, and applications (including biomedical applications); element and isotope transport and fixation; actinide and transition metal chemistry; structural chemistry, spectroscopy, and applications; nuclear structure and reactions; irradiation facilities; advanced analytical techniques; development and applications; atmospheric chemistry and transport; and earth and planetary processes.

  8. Impact of source terms on distances to which reactor accident consequences occur

    SciTech Connect (OSTI)

    Ostmeyer, R.M.

    1982-01-01T23:59:59.000Z

    Estimates of the distances over which reactor accident consequences might occur are important for development of siting criteria and for emergency response planning. This paper summarizes the results of a series of CRAC2 calculations performed to estimate these distances. Because of the current controversy concerning the magnitude of source terms for severe accidents, the impact of source term reductions upon distance estimates is also examined.

  9. Identification of the source of methane at a hazardous waste treatment facility using isotopic analysis

    SciTech Connect (OSTI)

    Hackley, K.C.; Liu, C.L. (Illinois State Geological Survey, Peabody, IL (United States)); Trainor, D.P. (Dames and Moore, Madison, WI (United States))

    1992-01-01T23:59:59.000Z

    Isotopic analyses have been used to determine the source of methane in subsurface sediments at a hazardous waste treatment facility in the Lake Calumet area of Chicago, Illinois. The study area is surrounded by landfills and other waste management operations and has a long history of waste disposal. The facility property consists of land constructed of approximately 15 feet of fill placed over lake sediments. The fill is underlain by successively older lacustrine and glacial till deposits to a maximum depth of approximately 80 feet. During a subsurface investigation of the site performed for a RCRA Facility Investigation of former solid waste management units (SWMUs) in the fill, significant quantities of methane were encountered in the natural deposits. Gas samples were collected from the headspace of 11 piezometers screened at depths of approximately 30, 40, and 50 feet beneath the surface. Methane concentrations up to 75% by volume were observed in some of the piezometers. Stable isotope analyses were completed on methane and associated CO[sub 2] separated from the gas samples. Radiocarbon (C-14) analyses were also completed on several of the samples. The delta C-13 results for the intermediate and deep zones are indicative of methane produced by microbial reduction of CO[sub 2]. The methane occurring in the shallow zone appears to be a mixture of methane from the intermediate zone and methane produced by microbial fermentation of naturally (nonanthropogenic) buried organic matter within the shallow lacustrine sediments. According to the isotopic and chemical results, the methane does not appear to be related to gas generation from nearby landfills or from organic wastes previously placed in the former facility SWMUs.

  10. Masses of Fundamental Particles

    E-Print Network [OSTI]

    Hidezumi Terazawa

    2014-06-11T23:59:59.000Z

    In the original paper entitled, "Masses of Fundamental Particles"(arXiv:1109.3705v5, 10 Feb 2012), not only the masses of fundamental particles including the weak bosons, Higgs boson, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite models of quarks and leptons successfully. In this addendum entitled, "Higgs Boson Mass in the Minimal Unified Subquark Model", it is emphasized that the Higgs boson mass is predicted to be about 130Gev in the minimal unified subquark model, which agrees well with the experimental values of 125-126GeV recently found by the ATLAS and CMS Collaborations at the LHC.

  11. Microlens Mass Functions

    E-Print Network [OSTI]

    William D. Heacox

    2005-10-10T23:59:59.000Z

    A non-parametric statistical model is constructed to directly relate The distribution of observed microlens timescales to that of the mass Function of the population from which the lenses are drawn, corrected For observational selection based on timescales and event amplifications. Explicit distributions are derived for microlensing impact parameters and maximum amplifications; both are shown to be statistically independent of all other parameters in the problem, including lens mass. The model is used to demonstrate that the narrow range of microlens timescales observed toward the Large Magellanic Cloud (LMC) is probably not consistent with lensing by a widely distributed spheroidal population of large velocity dispersion, as expected of a dark halo; but is consistent with lensing within a rotating thick disk. Poor numerical conditioning on the statistical connection between lens masses and event timescales, and small number statistics, severely limit the mass function information obtainable from current microlensing surveys toward the LMC.

  12. A Comparison of Shell Model Results for Some properties of the Even-Even Ge Isotopes

    E-Print Network [OSTI]

    S. J. Q. Robinson; L. Zamick; Y. Y. Sharon

    2010-07-13T23:59:59.000Z

    In this work we examine two recent effective shell model interactions, JUN45 and JJ4B, that have been proposed for use in the $f_{5/2},p_{3/2}, p_{1/2}, g_{9/2}$ model space for both protons and neutrons. We calculate a number of quantities that did not enter into the fits undertaken to fix the parameters of both interactions. In particular we consider static quadrupole moments (Q's) of excited states of the even-even $^{70-76}$Ge isotopes, as well as the B(E2) values in these nuclei. (We have previously studied $^{70}$Zn isotopes using JJ4B.) Some striking disagreements between the JUN45 prediction and the experimental results had already been noted for the quadrupole moments of the $2_1^+$ states of these nuclei. We investigate whether these discrepancies also occur for the JJ4B interaction. Subsequently, we also apply both interactions to calculate the Q's of some more highly excited states and compare the two sets of predictions regarding the nature of the nuclear states under consideration. In order to gain insight into these more complex large-scale shell-model calculations, we examine the corresponding and much simpler single-j shell model calculations in the $g_{9/2}$ neutron shell.

  13. HIGEE Mass Transfer

    E-Print Network [OSTI]

    Mohr, R. J.; Fowler, R.

    HIGEE MASS TRANSFER R.J. Mohr and R. Fowler GLITSCH, INC. Dallas, Texas ABSTRACT Distillation, absorption, and gas stripping have traditionally been performed in tall columns utilizing trays or packing. Columns perform satisfactorily... transfer system which utilizes a rotating bed of packing to achieve high efficiency separations, and consequent reduction in size and weight. INTRODUCTION HIGEE is probably one of the most interesting developments in mass transfer equipment made...

  14. Mass of Cu-57

    E-Print Network [OSTI]

    Gagliardi, Carl A.; Semon, D. R.; Tribble, Robert E.; Vanausdeln, L. A.

    1986-01-01T23:59:59.000Z

    the experimental and theoretical Coulomb displacement energies for similar cases in A =17 and 41 has been attributed~ to ground state correlations in the nuclear wave functions. It is in- teresting to examine the mass 57 mirror nuclei to investi- gate... indicated. Reference 9. 'Reference 7. Reference 6. 'This work. 34 MASS OF Cu 1665 the 3=57 Coulomb displacement energy, using radial wave functions obtained in a spherical Hartree-Fock cal- culation, assuming a closed Ni core, and including...

  15. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2011-01-01T23:59:59.000Z

    1.1 These test methods cover procedures for subsampling and for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride UF6. Most of these test methods are in routine use to determine conformance to UF6 specifications in the Enrichment and Conversion Facilities. 1.2 The analytical procedures in this document appear in the following order: Note 1—Subcommittee C26.05 will confer with C26.02 concerning the renumbered section in Test Methods C761 to determine how concerns with renumbering these sections, as analytical methods are replaced with stand-alone analytical methods, are best addressed in subsequent publications. Sections Subsampling of Uranium Hexafluoride 7 - 10 Gravimetric Determination of Uranium 11 - 19 Titrimetric Determination of Uranium 20 Preparation of High-Purity U3O 8 21 Isotopic Analysis 22 Isotopic Analysis by Double-Standard Mass-Spectrometer Method 23 - 29 Determination of Hydrocarbons, Chlorocarbons, and Partially Substitut...

  16. D/H isotope ratios of kerogen, bitumen, oil, and water in hydrous pyrolysis of source rocks containing kerogen types I, II, IIS, and III

    SciTech Connect (OSTI)

    Schimmelmann, A.; Lewan, M.D.; Wintsch, R.P.

    1999-11-01T23:59:59.000Z

    Immature source rock chips containing different types of kerogen (I,II,IIS,III) were artificially matured in isotopically distinct waters by hydrous pyrolysis and by pyrolysis in supercritical water. Converging isotopic trends of inorganic (water) and organic (kerogen, bitumen, oil) hydrogen with increasing time and temperature document that water-derived hydrogen is added to or exchanged with organic hydrogen, or both, during chemical reactions that take place during thermal maturation. Isotopic mass-balance calculations show that, depending on temperature (310--381 C), time (12--144h), and source rock type, between ca. 45 and 79% of carbon-bound hydrogen in kerogen is derived from water. Estimates for bitumen and oil range slightly lower, with oil-hydrogen being least affected by water-derived hydrogen. Comparative hydrous pyrolyses of immature source rocks at 330 C for 72h show that hydrogen in kerogen, bitumen, and expelled oil/wax ranks from most to least isotopically influenced by water-derived hydrogen in the order IIS {gt} II {approximately} III {gt} I. Pyrolysis of source rock containing type II kerogen in supercritical water at 381 C for 12 h yields isotopic results that are similar to those from hydrous pyrolysis at 250 C for 72 h or 330 C for 133 h. Bulk hydrogen in kerogen contains several percent of isotopically labile hydrogen that exchanges fast and reversibly with hydrogen in water vapor at 115 C. The isotopic equilibration of labile hydrogen in kerogen with isotopic standard water vapors significantly reduces the analytical uncertainty of D/H ratios when compared with simple D/H determination of bulk hydrogen in kerogen. If extrapolation of their results from hydrous pyrolysis is permitted to natural thermal maturation at lower temperatures, the authors suggest that organic D/H ratios of fossil fuels in contact with formation water are typically altered during chemical reactions, but that D/H ratios of generated hydrocarbons are subsequently little or not affected by exchange with water hydrogen at typical reservoir conditions over geologic time. It will be difficult to utilize D/H ratios of thermally mature bulk or fractions or organic matter to quantitatively reconstruct isotopic aspects of paleoclimate and paleoenvironment. Hope resides in compound-specific D/H ratio of thermally stable, extractable biomarkers (molecular fossils) that are less susceptible to hydrogen exchange with water-derived hydrogen.

  17. The marine geochemistry of iron and iron isotopes

    E-Print Network [OSTI]

    Bergquist, Bridget A., 1973-

    2004-01-01T23:59:59.000Z

    This thesis addressed questions about the Fe cycle by measuring detailed profiles and transects of Fe species in the ocean and also by exploring the use of a new tracer of Fe, Fe isotopic fractionation. In the subtropical ...

  18. acid selective isotope: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bchner; Grard Trnec; Jacques Vigu 2006-11-17 20 LACK OF CORRELATION BETWEEN GOUT AND THE INCORPORATION OF ISOTOPIC FORMATE INTO URIC ACID CiteSeer Summary: Certain...

  19. Recovery of enriched stable isotopes in radionuclide production

    SciTech Connect (OSTI)

    Razbash, A.A.; Sevastyanov, Yu.G.; Polyakov, O.N.; Krasnov, N.N.; Konyakhin, N.A.; Tolstouhov, Yu.V.; Maklachkov, A.G. [Cyclotron Co. Ltd., Obninsk (Russian Federation)

    1994-12-31T23:59:59.000Z

    The wide application of radionuclides in different fields of science and industry demanded an increase of their production. One of the ways to increase the radionuclide production on present cyclotrons is the use of the targets from enriched stable isotopes. This allows one to raise the productivity in some cases by two or more times and to increase radionuclidic purity. It should be noted, however, that enriched stable isotopes are very expensive. Therefore it is advisable to use such raw materials more than once. In the last ten years, The authors have used stable isotopes extensively for making of targets. Zinc-67 and zinc-68, cadmium-111 and cadmium-112, nickel-58, silver-109, thallium-203 have been employed for the production of gallium-67, indium-111, cobalt-57, cadmium-109 and thallium-201, respectively. The technique for the recovery of enriched stable isotopes has been developed. In this report the schemes of the recovering processes are presented.

  20. Isotopic Effect on Ion Mobility and Separation of Isotopomers...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Effect on Ion Mobility and Separation of Isotopomers by High-Field Ion Mobility Spectrometry . Isotopic Effect on Ion Mobility and Separation of Isotopomers by High-Field Ion...