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1

Advanced Mass Spectrometers for Hydrogen Isotope Analyses  

DOE Green Energy (OSTI)

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.

Chastagner, P.

2001-08-01T23:59:59.000Z

2

Comment on 'Existence of long-lived isomeric states in naturally-occurring neutron-deficient Th isotopes'  

SciTech Connect

In their article ''Existence of Long-Lived Isomeric States in Naturally-Occuring Neutron-Deficient Th Isotopes''[Phys. Rev. C 76, 021303 (2007)], Marinov et al. fail to demonstrate that basic mass spectrometric protocols, such as abundance sensitivity, linearity, and freedom from possible interferences, have been met. In particular, the claim that four isomeric states of Th have been discovered, using an inductively coupled plasma-sector field mass spectrometer (ICP-SFMS), with abundances from (1-10)x10{sup -11} relative to {sup 232}Th, cannot be accepted, given the known abundance sensitivities of other sector field mass spectrometers. Accelerator mass spectrometry is the only mass spectrometric methodology capable of measuring relative abundances of the magnitude claimed by Marinov et al.

Barber, R. C.; De Laeter, J. R. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Department of Applied Physics, Curtin University, Perth, Western Australia (Australia)

2009-04-15T23:59:59.000Z

3

Compact hydrogen/helium isotope mass spectrometer  

DOE Patents (OSTI)

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).

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

1996-01-01T23:59:59.000Z

4

Stable Isotope, Site-Specific Mass Tagging For Protein Identification  

NLE Websites -- All DOE Office Websites (Extended Search)

Stable Isotope, Site-Specific Mass Tagging For Protein Stable Isotope, Site-Specific Mass Tagging For Protein Identification Stable Isotope, Site-Specific Mass Tagging For Protein Identification Proteolytic peptide mass mapping as measured by mass spectrometry provides an important method for the identification of proteins, which are usually identified by matching the measured and calculated m/z values of the proteolytic peptides. Available for thumbnail of Feynman Center (505) 665-9090 Email Stable Isotope, Site-Specific Mass Tagging For Protein Identification Proteolytic peptide mass mapping as measured by mass spectrometry provides an important method for the identification of proteins, which are usually identified by matching the measured and calculated m/z values of the proteolytic peptides. A unique identification is, however, heavily

5

PYRO: New capability for isotopic mass tracking in pyroprocess simulation  

SciTech Connect

A new computational code package called PYRO has been developed to support the IFR fuel recycle demonstration project in the HFEF/S facility at ANL-W. The basic pyrochemical code PYRO1-1 models the atomic mass flows and phase compositions of 48 essential chemical elements involved in the pyroprocess. It has been extended to PYRO1-2 by linking with the ORIGEN code to track more than 1000 isotopic species, their radioactive decays, and related phenomena. This paper first describes the pyroprocess to be modeled and the pyrochemical capability that has been implemented in PYRO1-1, and then gives a full account on the algorithm of extending it to PYRO1-2 for isotopic mass tracking. Results from several scoping and simulation runs will be discussed to illustrate the significance of modeling in-process radioactive decays. 16 refs., 8 figs., 2 tabs.

Liaw, J.R.; Ackerman, J.P.

1990-01-01T23:59:59.000Z

6

Photon burst mass spectrometry--ultrasensitive detection of rare isotopes  

SciTech Connect

Progress is reported on the development of a new technique for measurement of trace levels of radioisotopes which is based on fluorescence detection of output from a mass spectrometer. Significant achievements include the observation of fluorescence and burst signals from Kr isotopes, including enriched samples of {sup 85}Kr with a 4-collector system. An abundance sensitivity is demonstrated with {sup 83}Kr and {sup 85}Kr.

Hansen, C.S.; Pan, X.J.; Fairbank, W.M. Jr. [Colorado State Univ., Fort Collins, CO (United States). Physics Dept.; Oona, H.; Chamberlin, E.P.; Nogar, N.S.; Fearey, B.L. [Los Alamos National Lab., NM (United States)

1995-02-01T23:59:59.000Z

7

New capability for isotopic mass tracking in pyroprocess simulation  

Science Conference Proceedings (OSTI)

In support of the Integral Fast Reactor fuel recycle demonstration project at Argonne's Hot Fuel Examination Facility-South (HFEF/S) facility, a new computational code package called PYRO has been developed. The basic PYRO code (version 1-1) models the atomic mass flows and phase compositions in the electrorefiner (pyrochemical reprocessing vessel). It has been extended in version 1-2 to include tracking of {approximately}800 isotopic masses, their radioactive decay, and related phenomena. In a demonstration simulation, the processing of 24 batches of spent Experimental Breeder Reactor II(EBR-II) U-10% Zr driver fuel (burnup {approximately}8%) containing 20 kg of uranium per batch was modeled.

Liaw, J.R.; Ackerman, J.P.

1989-01-01T23:59:59.000Z

8

Hydrogen-Isotope Mass-Spectrometer Evaluation Program. Bimonthly progress report, July/September 1982  

SciTech Connect

The joint SRL-SRP Hydrogen Isotope Mass Spectrometer Evaluation Program was undertaken to: (1) evaluate a prototype hydrogen isotope mass spectrometer that was developed for the Mass Spectrometer Technical Group by VG-Isotopes, Ltd., and (2) obtain sufficient data to permit SRP personnel to specify the mass spectrometes that will be purchased under Schedule 44 Budget Project 81-SR-010 to replace obsolete mass spectrometers in Buildings 232-H and 224-H.

Chastagner, P.; Daves, H.L.; Hess, W.B.

1982-01-01T23:59:59.000Z

9

Raman spectroscopic and mass spectrometric investigations of the hydrogen isotopes and isotopically labelled methane  

Science Conference Proceedings (OSTI)

Suitable analytical methods must be tested and developed for monitoring the individual process steps within the fuel cycle of a fusion reactor and for tritium accountability. The utility of laser-Raman spectroscopy accompanied by mass spectrometry with an Omegatron was investigated using the analysis of all hydrogen isotopes and isotopically labeled methanes as an example. The Omegatron is useful for analyzing all hydrogen isotopes mixed with the stable helium isotopes. The application of this mass spectrometer were demonstrated by analyzing mixtures of deuterated methanes. In addition, it was employed to study the radiochemical Witzbach exchange reaction between tritium and methanes. A laser-Raman spectrometer was designed for analysis of tritium-containing gases and was built from individual components. A tritium-compatible, metal-sealed Raman cuvette having windows with good optical properties and additional means for measuring the stray light was first used successfully in this work. The Raman spectra of the hydrogen isotopes were acquired in the pure rotation mode and in the rotation-vibration mode and were used for on. The deuterated methanes were measured by Raman spectroscopy, the wavenumbers determined were assigned to the corresponding vibrations, and the wavenumbers for the rotational fine-structure were summarized in tables. The fundamental Vibrations of the deuterated methanes produced Witzbach reactions were detected and assigned. The fundamental vibrations of the molecules were obtained with Raman spectroscopy for the first time in this work. The @-Raman spectrometer assembled is well suited for the analysis of tritium- containing gases and is practical in combination with mass spectrometry using an Omegatron, for studying gases used in fusion.

Jewett, J.R., Fluor Daniel Hanford

1997-02-24T23:59:59.000Z

10

Seven Channel Multi-collector Isotope Ratio Mass Spectrometer  

Science Conference Proceedings (OSTI)

A new magnetic sector mass spectrometer that utilizes seven full-sized discrete dynode electron multipliers operating simultaneously has been designed, constructed and is in preliminary testing. The instrument utilizes a newly developed ion dispersion lens that enables the mass dispersed individual isotope beams to be separated sufficiently (35 mm) to allow a full-sized discrete dynode pulse counting multiplier to be used for each beam. The ion dispersion lens is a two element electrostatic 90 degree sector device that causes the beam-to-beam dispersion to increase faster than the intra-beam dispersion. Each multiplier is contained in an isolated case with a deflector/condenser lens at the entrance. A 9-sample filament cartridge is mounted on a micro-manipulator two-axis stage that enables adjustment of the filament position with 10 micron resolution within the ion lens. Results of initial testing with actinides will be presented.

Anthony D. Appelhans

2008-07-01T23:59:59.000Z

11

January 28, 2011 Kinetic Isotope Effects Predicted Correctly for a Mass Ratio of 36  

E-Print Network (OSTI)

January 28, 2011 Kinetic Isotope Effects Predicted Correctly for a Mass, and it has chemical properties very similar to a hydrogen atom, but very large), and the dynamics was thermally averaged to yield temperature-dependent chemical reaction rate

Truhlar, Donald G

12

Correlations of experimental isotope shifts with spectroscopic and mass observables  

Science Conference Proceedings (OSTI)

Experimental differential observables relating to mean square charge radii, spectroscopic, and mass observables of even-even nuclei are presented for different regions in the nuclear chart. They exhibit remarkable correlations, not heretofore recognized, that provide a new perspective on structural evolution, especially in exotic nuclei. This can also be a guide for future measurements of charge radii, spectroscopic observables, and masses, as well as for future theoretical approaches.

Cakirli, R. B. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Department of Physics, University of Istanbul, Istanbul (Turkey); Casten, R. F. [Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Blaum, K. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany)

2010-12-15T23:59:59.000Z

13

Secondary Ionization Mass Spectrometric Analysis of Impurity Element Isotope Ratios in Nuclear Reactor Materials  

Science Conference Proceedings (OSTI)

Secondary ion mass spectrometry (SIMS) analysis has been used to measure isotope ratios of selected impurity elements in irradiated reactor materials. Samples of reactor materials such as graphite or aluminum alloys are obtained from fuel channels or supporting materials. During reactor operations and fuel burn up, some isotopic abundances change due to nuclear reactions and provide sensitive indicators of neutron fluence. The rate of change is related to cross section for a particular isotope. Different isotopes can be used as indicators of burn up during different stages in the reactor operating history. Isotope ratios of B are useful indicators for low burnup stages early in reactor operations, Ti isotope ratios are useful at later burn up stages, and Cl isotope ratios are useful in both early and later stages. Knowledge of the sample position within the reactor also yields information on the fluence shape or profile. In a sequence of samples from one reactor, 10B/11B ratios decreased from near natural values of 0.25 to blasting, plasma etching, and vacuum furnace treatment.

Gerlach, David C.; Cliff, John B.; Hurley, David E.; Reid, Bruce D.; Little, Winston W.; Meriwether, George H.; Wickham, Anthony J.; Simmons, Tere A.

2006-07-30T23:59:59.000Z

14

ISOTOPES  

E-Print Network (OSTI)

Theory of Isotope Separation as Applied to the Large~scale Production of 235 u National Nuclear Energy

Lederer, C. Michael

2013-01-01T23:59:59.000Z

15

Separation Of Uranium And Plutonium Isotopes For Measurement By Multi Collector Inductively Coupled Plasma Mass Spectroscopy  

Science Conference Proceedings (OSTI)

Uranium (U) and plutonium (Pu) isotopes in coral soils, contaminated by nuclear weapons testing in the northern Marshall Islands, were isolated by ion-exchange chromatography and analyzed by mass spectrometry. The soil samples were spiked with {sup 233}U and {sup 242}Pu tracers, dissolved in minerals acids, and U and Pu isotopes isolated and purified on commercially available ion-exchange columns. The ion-exchange technique employed a TEVA{reg_sign} column coupled to a UTEVA{reg_sign} column. U and Pu isotope fractions were then further isolated using separate elution schemes, and the purified fractions containing U and Pu isotopes analyzed sequentially using multi-collector inductively coupled plasma mass spectrometer (MCICP-MS). High precision measurements of {sup 234}U/{sup 235}U, {sup 238}U/{sup 235}U, {sup 236}U/{sup 235}U, and {sup 240}Pu/{sup 239}Pu in soil samples were attained using the described methodology and instrumentation, and provide a basis for conducting more detailed assessments of the behavior and transfer of uranium and plutonium in the environment.

Martinelli, R E; Hamilton, T F; Williams, R W; Kehl, S R

2009-03-29T23:59:59.000Z

16

Intramolecular Isotope Effects for the Study of Reactions with MassTransfer Limitations  

E-Print Network (OSTI)

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 effects. The oxidation of unfunctionalized hydrocarbons at mild conditions developed by Sir Derek Barton, the Gif reaction is the model used. The history is provided to demonstrate the relevance of using this model as one which could show the usefulness of this method. Evidence has been provided and used to theorize that the rate limiting step of the reaction may be diffusion of the reactants, not a chemical change. Starting materials were made which would allow for the measurement for both the intermolecular and intramolecular KIE and those values were compared. The results show that there is little difference between the intermolecular and intramolecular KIE, therefore the reaction is not diffusion controlled.

Wagner, Joshua G.

2009-05-01T23:59:59.000Z

17

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

SciTech Connect

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.

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

2010-02-05T23:59:59.000Z

18

New FORTRAN computer programs to acquire and process isotopic mass spectrometric data: Operator`s manual  

Science Conference Proceedings (OSTI)

This TM is one of a pair that describes ORNL-developed software for acquisition and processing of isotope ratio mass spectral data. This TM is directed at the laboratory analyst. No technical knowledge of the programs and programming is required. It describes how to create and edit files, how to acquire and process data, and how to set up files to obtain the desired results. The aim of this TM is to serve as a utilitarian instruction manual, a {open_quotes}how to{close_quotes} approach rather than a {open_quotes}why?{close_quotes}

Smith, D.H.; McKown, H.S.

1993-09-01T23:59:59.000Z

19

Short-lived isotopes and 23Na production in low mass AGB Stars  

E-Print Network (OSTI)

We discuss the synthesis of some short-lived isotopes and of 23Na in thermally pulsing AGB stars with initial mass of 2 Msun and two different metallicities (Z=1.5e-2, corresponding to the metal amount in the Sun, and Z=1e-4), representative of disk and halo stars, respectively. The different nucleosynthesis channels are illustrated in some details. As previously found, the 13C formed after each third dredge up episode is usually completely consumed by alpha captures before the onset of the subsequent thermal pulse, releasing neutrons. This is the most efficient neutron source in low mass AGB stars and the resulting s-process nucleosynthesis is at the origin of the solar main component. However, in the solar metallicity model, we find that the temperature of the first formed 13C pocket remains too low during the interpulse and the 13C is not completely burnt, being partially engulfed in the convective zone generated by the following thermal pulse. Due to the rapid convective mixing in this zone, the 13C is exposed to a larger temperature and a nucleosynthesis characterized by a relatively high neutron density develops. The main effect is the strong enhancement of isotopes located beyond some critical branching in the neutron-capture path, like 60Fe, otherwise only marginally produced during a standard s-process nucleosynthesis.

S. Cristallo; R. Gallino; O. Straniero; L. Piersanti; I. Dominguez

2006-06-15T23:59:59.000Z

20

New Precision Mass Measurements of Neutron-Rich Calcium and Potassium Isotopes and Three-Nucleon Forces  

Science Conference Proceedings (OSTI)

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 51K was measured for the first time, and the precision of the 51,52Ca 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, 52Ca 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.

Gallant, A. T. [TRIUMF, University of British Columbia; Bale, J. C. [TRIUMF, University of British Columbia/Simon Fraser University-Canada; Brunner, T. [TRIUMF, University of British Columbia; Chowdhury, U. [TRIUMF, University of British Columbia/ University of Manitoba-Canada; Ettenauer, S. [TRIUMF, University of British Columbia; Lennarz, A. [TRIUMF, University of British Columbia/Westfälische Wilhelms-Universität-Germany; Robertson, D. [TRIUMF, University of British Columbia; Simon, V. V. [TRIUMF-Canada/Ruprecht-Karls-Universität Heidelberg/Max-Planck-Inst.-Heidelberg, Germany; Chaudhuri, A. [TRIUMF, University of British Columbia; Holt, J. D. [UTK/ORNL; Kwiatkowski, A. A. [TRIUMF, University of British Columbia; Mané, E. [TRIUMF, University of British Columbia; Menéndez, J. [Inst. für Kernphysik, Tech. Univ. Darmstadt-Germany/ExtreMe Matter Inst., GSI-Darmstadt; Schultz, B. E. [TRIUMF, University of British Columbia; Simon, M. C. [TRIUMF, University of British Columbia; Andreoiu, C. [Simon Fraser University, Canada; Delheij, P. [TRIUMF, University of British Columbia; Pearson, M. [TRIUMF, University of British Columbia; Savajols, H. [GANIL, Caen cedex, France; Schwenk, A. [Inst. für Kernphysik, Tech. Univ. Darmstadt-Germany/ExtreMe Matter Inst., GSI-Darmstadt; Dilling, J. [TRIUMF, University of British Columbia

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

Science Conference Proceedings (OSTI)

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.

Biegalski, S; Buchholz, B

2009-08-26T23:59:59.000Z

22

ISOTOPIC MASS FRACTIONATION OF SOLAR WIND: EVIDENCE FROM FAST AND SLOW SOLAR WIND COLLECTED BY THE GENESIS MISSION  

Science Conference Proceedings (OSTI)

NASA's Genesis space mission returned samples of solar wind collected over {approx}2.3 years. We present elemental and isotopic compositions of He, Ne, and Ar analyzed in diamond-like carbon targets from the slow and fast solar wind collectors to investigate isotopic fractionation processes during solar wind formation. The solar wind provides information on the isotopic composition for most volatile elements for the solar atmosphere, the bulk Sun and hence, on the solar nebula from which it formed 4.6 Ga ago. Our data reveal a heavy isotope depletion in the slow solar wind compared to the fast wind composition by 63.1 {+-} 2.1 per mille for He, 4.2 {+-} 0.5 per mille amu{sup -1} for Ne and 2.6 {+-} 0.5 per mille amu{sup -1} for Ar. The three Ne isotopes suggest that isotopic fractionation processes between fast and slow solar wind are mass dependent. The He/H ratios of the collected slow and fast solar wind samples are 0.0344 and 0.0406, respectively. The inefficient Coulomb drag model reproduces the measured isotopic fractionation between fast and slow wind. Therefore, we apply this model to infer the photospheric isotopic composition of He, Ne, and Ar from our solar wind data. We also compare the isotopic composition of oxygen and nitrogen measured in the solar wind with values of early solar system condensates, probably representing solar nebula composition. We interpret the differences between these samples as being due to isotopic fractionation during solar wind formation. For both elements, the magnitude and sign of the observed differences are in good agreement with the values predicted by the inefficient Coulomb drag model.

Heber, Veronika S.; Baur, Heinrich; Wieler, Rainer [Institute for Geochemistry and Petrology, ETH Zurich, Clausiusstrasse 25, CH-8092 Zurich (Switzerland); Bochsler, Peter [Physikalisches Institut, Universitaet Bern, Sidlerstasse 5, CH-3012 Bern (Switzerland); McKeegan, Kevin D. [Department of Earth and Space Sciences, University of California Los Angeles, 595 Charles Young Drive East, Box 951567, Los Angeles, CA 90095-1567 (United States); Neugebauer, Marcia [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0092 (United States); Reisenfeld, Daniel B. [Department of Physics and Astronomy, University of Montana, Missoula, MT 59812 (United States); Wiens, Roger C., E-mail: heber@ess.ucla.edu [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2012-11-10T23:59:59.000Z

23

Systematics of magnetic dipole strength in the stable even-mass Mo isotopes  

SciTech Connect

The nuclides {sup 92}Mo, {sup 98}Mo, and {sup 100}Mo have been studied in photon-scattering experiments by using bremsstrahlung produced at an electron energy of 6 MeV at the ELBE accelerator of the Forschungszentrum Rossendorf and at electron energies from 3.2 to 3.8 MeV at the Dynamitron accelerator at the University of Stuttgart. Six dipole transitions in {sup 98}Mo and 19 in {sup 100}Mo were observed for the first time in the energy range from 2 to 4 MeV. The experimental results are compared with predictions of the shell model and with predictions of the quasiparticle random-phase approximation (QRPA) in a deformed basis. The latter show significant contributions of isovector-orbital and isovector-spin vibrations. The change of the magnetic dipole strength in the isotopic chain of the even-mass isotopes from {sup 92}Mo to {sup 100}Mo is discussed. The calculations within the QRPA are extrapolated to the particle-separation energies to estimate the possible influence of M1 strength on the stability of the nuclides against photodissociation in cosmic scenarios.

Rusev, G. [Institut fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, D-01314 Dresden (Germany); Institute for Nuclear Research and Nuclear Energy, BAS, BG-1784 Sofia (Bulgaria); Schwengner, R.; Doenau, F.; Erhard, M.; Grosse, E.; Junghans, A.R.; Kaeubler, L.; Kosev, K.; Mallion, S.; Schilling, K.D.; Wagner, A. [Institut fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, D-01314 Dresden (Germany); Frauendorf, S. [Institut fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, D-01314 Dresden (Germany); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Kostov, L.K. [Institute for Nuclear Research and Nuclear Energy, BAS, BG-1784 Sofia (Bulgaria); Garrel, H. von; Kneissl, U.; Kohstall, C.; Kreutz, M.; Pitz, H.H.; Scheck, M.; Stedile, F. [Institut fuer Strahlenphysik, Universitaet Stuttgart, D-70569 Stuttgart (Germany)] (and others)

2006-04-15T23:59:59.000Z

24

Short-lived isotopes and 23Na production in low mass AGB Stars  

E-Print Network (OSTI)

We discuss the synthesis of some short-lived isotopes and of 23Na in thermally pulsing AGB stars with initial mass of 2 Msun and two different metallicities (Z=1.5e-2, corresponding to the metal amount in the Sun, and Z=1e-4), representative of disk and halo stars, respectively. The different nucleosynthesis channels are illustrated in some details. As previously found, the 13C formed after each third dredge up episode is usually completely consumed by alpha captures before the onset of the subsequent thermal pulse, releasing neutrons. This is the most efficient neutron source in low mass AGB stars and the resulting s-process nucleosynthesis is at the origin of the solar main component. However, in the solar metallicity model, we find that the temperature of the first formed 13C pocket remains too low during the interpulse and the 13C is not completely burnt, being partially engulfed in the convective zone generated by the following thermal pulse. Due to the rapid convective mixing in this zone, the 13C is ex...

Cristallo, S; Straniero, O; Piersanti, L; Dominguez, I

2006-01-01T23:59:59.000Z

25

Isotopic yield measurement in the heavy mass region for {sup 239}Pu thermal neutron induced fission  

SciTech Connect

Despite the huge number of fission yield data available in the different evaluated nuclear data libraries, such as JEFF-3.1.1, ENDF/B-VII.0, and JENDL-4.0, more accurate data are still needed both for nuclear energy applications and for our understanding of the fission process itself. It is within the framework of this that measurements on the recoil mass spectrometer Lohengrin (at the Institut Laue-Langevin, Grenoble, France) was undertaken, to determine isotopic yields for the heavy fission products from the {sup 239}Pu(n{sub th},f) reaction. In order to do this, a new experimental method based on {gamma}-ray spectrometry was developed and validated by comparing our results with those performed in the light mass region with completely different setups. Hence, about 65 fission product yields were measured with an uncertainty that has been reduced on average by a factor of 2 compared to that previously available in the nuclear data libraries. In addition, for some fission products, a strongly deformed ionic charge distribution compared to a normal Gaussian shape was found, which was interpreted as being caused by the presence of a nanosecond isomeric state. Finally, a nuclear charge polarization has been observed in agreement, with the one described on other close fissioning systems.

Bail, A.; Serot, O.; Mathieu, L.; Litaize, O.; Materna, T.; Koester, U.; Faust, H.; Letourneau, A.; Panebianco, S. [CEA, DEN-Cadarache, F-13108 Saint-Paul-lez-Durance (France); Institut Laue Langevin, 6 rue Jules Horowitz, B.P. 156, F-38042, Grenoble (France); CEA, DSM-Saclay, IRFU/SPhN, F-91191 Gif-sur-Yvette (France)

2011-09-15T23:59:59.000Z

26

Measurement of dissolved neon by isotope dilution using a quadrupole mass spectrometer  

E-Print Network (OSTI)

and finally air. A special technique for sealing in whichsealing end. ple times by reverse isotope dilution with air.

Hamme, Roberta C; Emerson, Steven R

2004-01-01T23:59:59.000Z

27

ISOTOPES  

E-Print Network (OSTI)

as occurs in batch distillation. The urgency of developingor one plate of a distillation column, for example. Anas in the case of a distillation column, for which any other

Lederer, C. Michael

2013-01-01T23:59:59.000Z

28

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

Science Conference Proceedings (OSTI)

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.

Isselhardt, B H

2011-09-06T23:59:59.000Z

29

Precision mass measurements of very short-lived, neutron-rich Na isotopes using a radiofrequency spectrometer  

E-Print Network (OSTI)

Mass measurements of high precision have been performed on sodium isotopes out to $^{30}$Na using a new technique of radiofrequency excitation of ion trajectories in a homogeneous magnetic field. This method, especially suited to very short-lived nuclides, has allowed us to significantly reduce the uncertainty in mass of the most exotic Na isotopes: a relative error of 5\\audi was achieved for $^{28}$Na having a half-life of only 30.5 ms and 9\\audi for the weakly produced $^{30}$Na. Verifying and minimizing binding energy uncertainties in this region of the nuclear chart is important for clarification of a long standing problem concerning the strength of the $N~=~20$ magic shell closure. These results are the fruit of the commissioning of the new experimental program Mistral.

Lunney, M D; Doubre, H; Henry, S; Monsanglant, C; De Saint-Simon, M; Thibault, C; Toader, C F; Borcea, C; Bollen, G

2001-01-01T23:59:59.000Z

30

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

Science Conference Proceedings (OSTI)

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.

Maxwell, S.

2010-07-26T23:59:59.000Z

31

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

Science Conference Proceedings (OSTI)

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.

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

2010-06-23T23:59:59.000Z

32

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

E-Print Network (OSTI)

4.5 Uranium Isotope Ratio Measurements . . . . . .4.32 Uranium sputtered from three U-rich materials of varying uranium isotopic

Isselhardt, Brett Hallen

2011-01-01T23:59:59.000Z

33

Shape trends and triaxiality in neutron-rich odd-mass Y and Nb isotopes  

E-Print Network (OSTI)

Shape trends and triaxiality in neutron-rich odd-mass Y andseries, following a similar trend in the neighboring even-Fig. 6 follow similar trends over a wide frequency region,

2004-01-01T23:59:59.000Z

34

It's Elemental - Isotopes of the Element Radon  

NLE Websites -- All DOE Office Websites (Extended Search)

Astatine Astatine Previous Element (Astatine) The Periodic Table of Elements Next Element (Francium) Francium Isotopes of the Element Radon [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Radon has no naturally occurring isotopes. Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 193 1.15 milliseconds Alpha Decay 100.00% 194 0.78 milliseconds Alpha Decay 100.00% 195 6 milliseconds Alpha Decay 100.00% 195m 5 milliseconds Alpha Decay 100.00% 196 4.4 milliseconds Alpha Decay 99.90% Electron Capture ~ 0.10% 197 53 milliseconds Alpha Decay 100.00% 197m 25 milliseconds Alpha Decay 100.00% 198 65 milliseconds Alpha Decay No Data Available

35

It's Elemental - Isotopes of the Element Francium  

NLE Websites -- All DOE Office Websites (Extended Search)

Radon Radon Previous Element (Radon) The Periodic Table of Elements Next Element (Radium) Radium Isotopes of the Element Francium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Francium has no naturally occurring isotopes. Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 199 12 milliseconds Alpha Decay > 0.00% Electron Capture No Data Available 200 49 milliseconds Alpha Decay 100.00% 201 62 milliseconds Alpha Decay 100.00% 201m 19 milliseconds Alpha Decay 100.00% 202 0.30 seconds Alpha Decay 100.00% 202m 0.29 seconds Alpha Decay 100.00% 203 0.55 seconds Alpha Decay <= 100.00% 204 1.8 seconds Alpha Decay 92.00%

36

Discovery of {sup 229}Rn and the Structure of the Heaviest Rn and Ra Isotopes from Penning-Trap Mass Measurements  

SciTech Connect

The masses of the neutron-rich radon isotopes {sup 223-229}Rn have been determined for the first time, using the ISOLTRAP setup at CERN ISOLDE. In addition, this experiment marks the first discovery of a new nuclide, {sup 229}Rn, by Penning-trap mass measurement. The new, high-accuracy data allow a fine examination of the mass surface, via the valence-nucleon interaction {delta}V{sub pn}. The results reveal intriguing behavior, possibly reflecting either a N=134 subshell closure or an octupolar deformation in this region.

Neidherr, D.; Boehm, Ch. [Institut fuer Physik, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Audi, G.; Lunney, D.; Minaya-Ramirez, E.; Naimi, S. [CSNSM-IN2P3-CNRS, Universite de Paris Sud, Orsay (France); Beck, D.; Herfurth, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH Darmstadt, 64291 Darmstadt (Germany); Blaum, K.; George, S.; Kellerbauer, A. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Breitenfeldt, M.; Rosenbusch, M.; Schweikhard, L. [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Cakirli, R. B. [Institut fuer Kernphysik der Universitaet zu Koeln, 50937 Koeln (Germany); Department of Physics, Istanbul University, Istanbul (Turkey); Casten, R. F. [Institut fuer Kernphysik der Universitaet zu Koeln, 50937 Koeln (Germany); Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520-8124 (United States); Herlert, A.; Kowalska, M. [Physics Department, CERN, 1211 Geneva 23 (Switzerland); Noah, E.; Penescu, L. [Accelerators and Beams Department, CERN, 1211 Geneva 23 (Switzerland)] (and others)

2009-03-20T23:59:59.000Z

37

Isotope ratio analysis of actinides, fission products, and geolocators by high-efficiency multi-collector thermal ionization mass spectrometry  

SciTech Connect

A ThermoFisher 'Triton' multi-collector thermal ionization mass spectrometer (MC-TIMS) was evaluated for trace and ultra-trace level isotoperatioanalysis of actinides (uranium, plutonium, and americium), fission products and geolocators (strontium, cesium, and neodymium). Total efficiencies (atoms loaded to ions detected) of up to 0.5-2% for U, Pu, and Am, and 1-30% for Sr, Cs, and Nd can be reported employing resin bead load techniques onto flat ribbon Re filaments or resin beads loaded into a millimeter-sized cavity drilled into a Re rod. This results in detection limits of <0.1 fg (10{sup 4} atoms to 10{sup 5} atoms) for {sup 239-242+244}Pu, {sup 233+236}U, {sup 241-243}Am, {sup 89,90}Sr, and {sup 134,135,137}Cs, and {le} 1 pg for natural Nd isotopes (limited by the chemical processing blank) using a secondary electron multiplier (SEM) or multiple-ion counters (MICs). Relative standard deviations (RSD) as small as 0.1% and abundance sensitivities of 1 x 10{sup 6} or better using a SEM are reported here. Precisions of RSD {approx} 0.01-0.001% using a multi-collector Faraday cup array can be achieved at sub-nanogram concentrations for strontium and neodymium and are suitable to gain crucial geolocation information. The analytical protocols reported herein are of particular value for nuclear forensic and nuclear safeguard applications.

Bürger, Stefan [New Brunswick Laboratory, Argonne, IL; Riciputi, Lee R [Los Alamos National Laboratory (LANL); Bostick, Debra A [ORNL; Turgeon, Steven [University of Alberta, Edmondton, Canada; McBay, Eddie H [ORNL; Lavelle, Mark [ORNL

2009-01-01T23:59:59.000Z

38

Measuring Mercury Isotopes in the Atmosphere and Rainfall near a Coal-Fired Power Plant  

Science Conference Proceedings (OSTI)

Recent work has shown that the seven naturally occurring stable isotopes of mercury (Hg) undergo mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) during transformation processes, especially during chemical oxidation and reduction (redox) reactions that can occur in the atmosphere. The isotopic patterns resulting from fractionation can be used to help trace the sources of Hg in the environment and to help clarify the mechanisms of Hg cycling. This project was designed with ...

2013-11-19T23:59:59.000Z

39

It's Elemental - Isotopes of the Element Magnesium  

NLE Websites -- All DOE Office Websites (Extended Search)

Sodium Sodium Previous Element (Sodium) The Periodic Table of Elements Next Element (Aluminum) Aluminum Isotopes of the Element Magnesium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 24 78.99% STABLE 25 10.00% STABLE 26 11.01% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 19 4.0 picoseconds Double Proton Emission 100.00% 20 90.8 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission ~ 27.00% 21 122 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 32.60% Electron Capture with delayed Alpha Decay < 0.50%

40

It's Elemental - Isotopes of the Element Chlorine  

NLE Websites -- All DOE Office Websites (Extended Search)

Sulfur Sulfur Previous Element (Sulfur) The Periodic Table of Elements Next Element (Argon) Argon Isotopes of the Element Chlorine [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 35 75.76% STABLE 37 24.24% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 28 No Data Available Proton Emission (suspected) No Data Available 29 < 20 nanoseconds Proton Emission No Data Available 30 < 30 nanoseconds Proton Emission No Data Available 31 150 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 0.70% 32 298 milliseconds Electron Capture 100.00%

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

It's Elemental - Isotopes of the Element Potassium  

NLE Websites -- All DOE Office Websites (Extended Search)

Argon Argon Previous Element (Argon) The Periodic Table of Elements Next Element (Calcium) Calcium Isotopes of the Element Potassium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 39 93.2581% STABLE 40 0.0117% 1.248×10+9 years 41 6.7302% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 32 No Data Available Proton Emission (suspected) No Data Available 33 < 25 nanoseconds Proton Emission No Data Available 34 < 25 nanoseconds Proton Emission No Data Available 35 178 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 0.37% 36 342 milliseconds Electron Capture 100.00%

42

It's Elemental - Isotopes of the Element Oxygen  

NLE Websites -- All DOE Office Websites (Extended Search)

Nitrogen Nitrogen Previous Element (Nitrogen) The Periodic Table of Elements Next Element (Fluorine) Fluorine Isotopes of the Element Oxygen [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 16 99.757% STABLE 17 0.038% STABLE 18 0.205% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 12 1.139×10-21 seconds Proton Emission No Data Available 13 8.58 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 100.00% 14 70.620 seconds Electron Capture 100.00% 15 122.24 seconds Electron Capture 100.00% 16 STABLE - - 17 STABLE - - 18 STABLE - - 19 26.88 seconds Beta-minus Decay 100.00%

43

It's Elemental - Isotopes of the Element Gallium  

NLE Websites -- All DOE Office Websites (Extended Search)

Zinc Zinc Previous Element (Zinc) The Periodic Table of Elements Next Element (Germanium) Germanium Isotopes of the Element Gallium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 69 60.108% STABLE 71 39.892% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 56 No Data Available Proton Emission (suspected) No Data Available 57 No Data Available Proton Emission (suspected) No Data Available 58 No Data Available Proton Emission (suspected) No Data Available 59 No Data Available Proton Emission (suspected) No Data Available 60 70 milliseconds Electron Capture 98.40%

44

It's Elemental - Isotopes of the Element Sodium  

NLE Websites -- All DOE Office Websites (Extended Search)

Neon Neon Previous Element (Neon) The Periodic Table of Elements Next Element (Magnesium) Magnesium Isotopes of the Element Sodium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 23 100% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 18 1.3×10-21 seconds Proton Emission 100.00% 19 < 40 nanoseconds Proton Emission No Data Available 20 447.9 milliseconds Electron Capture with delayed Alpha Decay 20.05% Electron Capture 100.00% 21 22.49 seconds Electron Capture 100.00% 22 2.6027 years Electron Capture 100.00% 23 STABLE - - 24 14.997 hours Beta-minus Decay 100.00%

45

It's Elemental - Isotopes of the Element Neon  

NLE Websites -- All DOE Office Websites (Extended Search)

Fluorine Fluorine Previous Element (Fluorine) The Periodic Table of Elements Next Element (Sodium) Sodium Isotopes of the Element Neon [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 20 90.48% STABLE 21 0.27% STABLE 22 9.25% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 16 9×10-21 seconds Double Proton Emission 100.00% 17 109.2 milliseconds Electron Capture with delayed Alpha Decay No Data Available Electron Capture 100.00% Electron Capture with delayed Proton Emission 100.00% 18 1.6670 seconds Electron Capture 100.00% 19 17.22 seconds Electron Capture 100.00% 20 STABLE - -

46

It's Elemental - Isotopes of the Element Copper  

NLE Websites -- All DOE Office Websites (Extended Search)

Nickel Nickel Previous Element (Nickel) The Periodic Table of Elements Next Element (Zinc) Zinc Isotopes of the Element Copper [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 63 69.15% STABLE 65 30.85% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 52 No Data Available Proton Emission No Data Available 53 < 300 nanoseconds Electron Capture No Data Available Proton Emission No Data Available 54 < 75 nanoseconds Proton Emission No Data Available 55 27 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 15.0% 56 93 milliseconds Electron Capture 100.00%

47

It's Elemental - Isotopes of the Element Boron  

NLE Websites -- All DOE Office Websites (Extended Search)

Beryllium Beryllium Previous Element (Beryllium) The Periodic Table of Elements Next Element (Carbon) Carbon Isotopes of the Element Boron [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 10 19.9% STABLE 11 80.1% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 6 No Data Available Double Proton Emission (suspected) No Data Available 7 3.255×10-22 seconds Proton Emission No Data Available Alpha Decay No Data Available 8 770 milliseconds Electron Capture 100.00% Electron Capture with delayed Alpha Decay 100.00% 9 8.439×10-19 seconds Proton Emission 100.00% Double Alpha Decay 100.00%

48

It's Elemental - Isotopes of the Element Tungsten  

NLE Websites -- All DOE Office Websites (Extended Search)

Tantalum Tantalum Previous Element (Tantalum) The Periodic Table of Elements Next Element (Rhenium) Rhenium Isotopes of the Element Tungsten [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 180 0.12% >= 6.6×10+17 years 182 26.50% STABLE 183 14.31% > 1.3×10+19 years 184 30.64% STABLE 186 28.43% > 2.3×10+19 years Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 157 275 milliseconds Electron Capture No Data Available 158 1.25 milliseconds Alpha Decay 100.00% 158m 0.143 milliseconds Isomeric Transition No Data Available Alpha Decay No Data Available 159 7.3 milliseconds Alpha Decay ~ 99.90%

49

It's Elemental - Isotopes of the Element Carbon  

NLE Websites -- All DOE Office Websites (Extended Search)

Boron Boron Previous Element (Boron) The Periodic Table of Elements Next Element (Nitrogen) Nitrogen Isotopes of the Element Carbon [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 12 98.93% STABLE 13 1.07% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 8 1.981×10-21 seconds Proton Emission 100.00% Alpha Decay No Data Available 9 126.5 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 61.60% Electron Capture with delayed Alpha Decay 38.40% 10 19.308 seconds Electron Capture 100.00% 11 20.334 minutes Electron Capture 100.00% 12 STABLE - -

50

It's Elemental - Isotopes of the Element Rhenium  

NLE Websites -- All DOE Office Websites (Extended Search)

Tungsten Tungsten Previous Element (Tungsten) The Periodic Table of Elements Next Element (Osmium) Osmium Isotopes of the Element Rhenium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 185 37.40% STABLE 187 62.60% 4.33×10+10 years Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 159 No Data Available No Data Available No Data Available 160 0.82 milliseconds Proton Emission 91.00% Alpha Decay 9.00% 161 0.44 milliseconds Proton Emission 100.00% Alpha Decay <= 1.40% 161m 14.7 milliseconds Alpha Decay 93.00% Proton Emission 7.00% 162 107 milliseconds Alpha Decay 94.00% Electron Capture 6.00%

51

It's Elemental - Isotopes of the Element Phosphorus  

NLE Websites -- All DOE Office Websites (Extended Search)

Silicon Silicon Previous Element (Silicon) The Periodic Table of Elements Next Element (Sulfur) Sulfur Isotopes of the Element Phosphorus [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 31 100% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 24 No Data Available Electron Capture (suspected) No Data Available Proton Emission (suspected) No Data Available 25 < 30 nanoseconds Proton Emission 100.00% 26 43.7 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission No Data Available 27 260 milliseconds Electron Capture 100.00% Electron Capture with

52

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

Science Conference Proceedings (OSTI)

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.

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

53

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)

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.

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

2006-01-27T23:59:59.000Z

54

Determination of a mass isotope effect on T{sub c} in an electron-donor-based organic superconductor, k-(ET){sub 2}Cu(NCS){sub 2}, where ET represents bis(ethylenedithio)tetrathiafulvalene.  

Science Conference Proceedings (OSTI)

We describe the first determination of a genuine mass isotope effect on {Tc} arising from the isotopic substitution of atoms in the ET [bis(ethylenedithio)tetrathiafulvalene] molecule of an electron-donor-based organic superconductor, {kappa}-(ET){sub 2}Cu(NCS){sub 2} ({Tc} = 9.6 K, inductive onset). The isotopic substitution in the ET molecule involves concurrent replacement of the four carbon atoms in the terminal 1,2-ethanediyl groups with {sup 13}C and all eight sulfur atoms with {sup 34}S. This substitution, {sup 13}C(4){sup 34}S(8), increases the mass of the ET molecule by 20 amu, which is a 5% increase in the normal mass. With the use of AC susceptibility measurements on a large sampling of single crystals, including both undeuterated and fully deuterated salts, we obtain {Delta}{Tc} = -0.12 {+-} 0.05 K for this isotope effect. Assuming a BCS-like mass effect with ET as the relevant mass entity (M), this effect gives {alpha} = 0.26 {+-} 0.11 for {Tc}{alpha}M{sup -{alpha}}. Additionally, our experiments with fully deuterated {kappa}-(ET){sub 2}Cu(NCS){sub 2} ({sup 2}H replacing eight hydrogen atoms in ET) confirm the occurrence of a large inverse isotope effect for the deuteration, and yield the first definitive value for this effect, {Delta}{Tc} = +0.28 {+-} 0.06 K. The isotope effect for {sup 13}C(4){sup 34}S(8) substitution, however, is unaffected by deuteration. Contrary to an earlier report by others, we find a zero isotope effect within {+-}0.06 K for {sup 13}C(4) substitution alone.

Kini, A. M.; Carlson, K. D.; Wang, H. H.; Schlueter, J. A.; Dudek, J. D.; Sirchio, S. A.; Geiser, U.; Lykke, K. R.; Williams, J. M.

1996-06-01T23:59:59.000Z

55

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

Science Conference Proceedings (OSTI)

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.

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

2011-09-15T23:59:59.000Z

56

Extraction Chromatographic Methods in the Sample Preparation Sequence for Thermal Ionization Mass Spectrometric Analysis of Plutonium Isotopes  

Science Conference Proceedings (OSTI)

A sample preparation sequence for actinide isotopic analysis by TIMS is described that includes column-based extraction chromatography as the first separation step, followed by anion exchange column separations. The sequence is designed to include a wet ashing step after the extraction chromatography to prevent any leached extractant or oxalic acid eluent reagents from interfering with subsequent separations, source preparation, or TIMS ionization. TEVA-resin and DGA-resin materials, containing extractants that consist only of C, N, O, and H atoms, were investigated for isolation of plutonium. Radiotracer level studies confirmed expected high yields from column-based separation procedures. Femtogram-level studies were carried out with TIMS detection, using multiple isotopic spikes through the separation sequence. Pu recoveries were 87% and 86% for TEVA- and DGA-resins separations respectively. The Pu recoveries from 400 {mu}L anion-exchange column separations were 89% and 93% for trial sequences incorporating TEVA and DGA-resin. Thus, a prior extraction chromatography step in the sequence did not interfere with the subsequent anion exchange separation when a simple wet ash step was carried out in between these column separations. The average measurement efficiency, for Pu, encompassing the chemical separation recoveries and the TIMS ionization efficiency, was 2.73 {+-} 0.77% (2-sigma) for the DGA-resin trials and 2.67 {+-} 0.54% for the TEVA-resin trials, compared to 3.41% and 2.37% (average 2.89%) for two spikes in the experimental set. These compare with an average measurement efficiency of 2.78 {+-} 1.70%, n = 33 from process benchmark analyses using Pu spikes processed through a sequence of oxalate precipitation, wet ash, iron hydroxide precipitation, and anion exchange column separations. We conclude that extraction chromatography can be a viable separation procedure as part of a multistep sequence for TIMS sample preparation.

Grate, Jay W.; O'Hara, Matthew J.; Farawila, Anne F.; Douglas, Matthew; Haney, Morgan M.; Peterson, Steve L.; Maiti, Tapas C.; Aardahl, Christopher L.

2011-10-17T23:59:59.000Z

57

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

SciTech Connect

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.

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

2012-01-01T23:59:59.000Z

58

It's Elemental - Isotopes of the Element Nitrogen  

NLE Websites -- All DOE Office Websites (Extended Search)

Carbon Carbon Previous Element (Carbon) The Periodic Table of Elements Next Element (Oxygen) Oxygen Isotopes of the Element Nitrogen [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 14 99.636% STABLE 15 0.364% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 10 No Data Available Proton Emission 100.00% 11 5.49×10-22 seconds Proton Emission 100.00% 12 11.000 milliseconds Electron Capture 100.00% 13 9.965 minutes Electron Capture 100.00% 14 STABLE - - 15 STABLE - - 16 7.13 seconds Beta-minus Decay 100.00% Beta-minus Decay with delayed Alpha Decay 1.2×10-3 % 17 4.173 seconds Beta-minus Decay 100.00%

59

Laser isotope separation  

DOE Patents (OSTI)

A process and apparatus for separating isotopes by selective excitation of isotopic species of a volatile compound by tuned laser light is described. 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.

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

1975-11-26T23:59:59.000Z

60

The global geochemical cycles of iron and calcium: using novel isotope systems to understand weathering, global mass budgets, natural reaction rates, and paleoclimate  

E-Print Network (OSTI)

in the sedimentary column, and diagenetic alteration of Ca isotope signals over geologic time scales. The overallThe global geochemical cycles of iron and calcium: using novel isotope systems to understand of Doctor of Philosophy in Geology in the GRADUATE DIVISION of the UNIVERSITY OF CALIFORNIA, BERKELEY

Fantle, Matthew

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Natural mercury isotope variation in coal deposits and organic soils  

SciTech Connect

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.

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

62

Detection of triclocarban and two co-contaminating chlorocarbanilides in US aquatic environments using isotope dilution liquid chromatography tandem mass spectrometry  

SciTech Connect

The antimicrobial compound triclocarban (TCC; 3,4,4'-trichlorocarbanilide; CAS-bar 101-20-2) is a high-production-volume chemical, recently suggested to cause widespread contamination of US water resources. To test this hypothesis, we developed an isotope dilution liquid chromatography electrospray ionization tandem mass spectrometry method for ultratrace analysis of TCC (0.9ng/L detection limit) and analyzed low-volume water samples (200mL) along with primary sludge samples from across the United States. All river water samples (100%) collected downstream of wastewater treatment plants had detectable levels of TCC, as compared to 56% of those taken upstream. Concentrations of TCC (mean+/-standard deviation) downstream of sewage treatment plants (84+/-110ng/L) were significantly higher (P<0.05; Wilcoxon rank sum test) than those of samples taken upstream (12+/-15ng/L). Compared to surface water, mean TCC concentrations found in dried, primary sludge obtained from municipal sewage treatment plants in five states were six orders of magnitude greater (19,300+/-7100{mu}g/kg). Several river samples contained a co-contaminant, identified based on its chromatographic retention time, molecular base ion, and MS/MS fragmentation behavior as 4,4'-dichlorocarbanilide (DCC; CAS-bar 1219-99-4). In addition to TCC and DCC, municipal sludge contained a second co-contaminant, 3,3',4,4'-tetrachlorocarbanilide (TetraCC; CAS-bar 4300-43-0). Both newly detected compounds were present as impurities (0.2%{sub w/w} each) in technical grade TCC (99%). Application of the new method for chlorocarbanilide analysis yielded TCC occurrence data for 13 US states, confirmed the role of sewage treatment plants as environmental inputs of TCC, and identified DCC and TetraCC as previously unrecognized pollutants released into the environment alongside TCC.

Sapkota, Amir [Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, Johns Hopkins University Center for Water and Health, Baltimore, MD 21205-2103 (United States); Heidler, Jochen [Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, Johns Hopkins University Center for Water and Health, Baltimore, MD 21205-2103 (United States); Halden, Rolf U. [Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, Johns Hopkins University Center for Water and Health, Baltimore, MD 21205-2103 (United States)]. E-mail: rhalden@jhsph.edu

2007-01-15T23:59:59.000Z

63

Definition: Isotopic Analysis | Open Energy Information  

Open Energy Info (EERE)

Analysis Analysis Jump to: navigation, search Dictionary.png Isotopic Analysis Isotopes are atoms of the same element that have different numbers of neutrons. An isotopic analysis looks at a particular isotopic element(s) in a given system, while the conditions which increase/decrease the number of neutrons are well understood and measurable.[1] View on Wikipedia Wikipedia Definition Isotope analysis is the identification of isotopic signature, the distribution of certain stable isotopes and chemical elements within chemical compounds. This can be applied to a food web to make it possible to draw direct inferences regarding diet, trophic level, and subsistence. Isotope ratios are measured using mass spectrometry, which separates the different isotopes of an element on the basis of their mass-to-charge

64

Expression of Stable Isotopically Labeled Proteins for Use as ...  

Science Conference Proceedings (OSTI)

Expression of Stable Isotopically Labeled Proteins for Use as Internal Standards for Mass Spectrometric Quantitation of Clinical Protein Biomarkers. ...

2013-03-13T23:59:59.000Z

65

It's Elemental - Isotopes of the Element Rhodium  

NLE Websites -- All DOE Office Websites (Extended Search)

Isotopes Mass Number Half-life Decay Mode Branching Percentage 89 1.5 microseconds Electron Capture (suspected) No Data Available Proton Emission (suspected) No Data Available...

66

It's Elemental - Isotopes of the Element Promethium  

NLE Websites -- All DOE Office Websites (Extended Search)

Isotopes Mass Number Half-life Decay Mode Branching Percentage 126 No Data Available Electron Capture (suspected) No Data Available 127 No Data Available Proton Emission...

67

It's Elemental - Isotopes of the Element Niobium  

NLE Websites -- All DOE Office Websites (Extended Search)

Isotopes Mass Number Half-life Decay Mode Branching Percentage 81 < 200 nanoseconds Electron Capture No Data Available 82 50 milliseconds Electron Capture 100.00% Electron...

68

It's Elemental - Isotopes of the Element Indium  

NLE Websites -- All DOE Office Websites (Extended Search)

Isotopes Mass Number Half-life Decay Mode Branching Percentage 97 No Data Available Electron Capture (suspected) No Data Available Proton Emission (suspected) No Data Available...

69

It's Elemental - Isotopes of the Element Cerium  

NLE Websites -- All DOE Office Websites (Extended Search)

Isotopes Mass Number Half-life Decay Mode Branching Percentage 119 No Data Available Electron Capture (suspected) No Data Available 120 No Data Available Electron Capture...

70

Oxygen Isotopes  

NLE Websites -- All DOE Office Websites (Extended Search)

Pages to Isotopes Data Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon Dioxide and Carbon-13 in Methane 800,000 Deuterium Record and Shorter Records of...

71

Apparatus for storing hydrogen isotopes  

DOE Green Energy (OSTI)

An improved method and apparatus for storing isotopes of hydrogen (especially tritium) are provided. The hydrogen gas(es) is (are) stored as hydrides of material (for example uranium) within boreholes in a block of copper. The mass of the block is critically important to the operation, as is the selection of copper, because no cooling pipes are used. Because no cooling pipes are used, there can be no failure due to cooling pipes. And because copper is used instead of stainless steel, a significantly higher temperature can be reached before the eutectic formation of uranium with copper occurs, (the eutectic of uranium with the iron in stainless steel forming at a significantly lower temperature).

McMullen, John W. (Los Alamos, NM); Wheeler, Michael G. (Los Alamos, NM); Cullingford, Hatice S. (Houston, TX); Sherman, Robert H. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

72

Carbon Isotopes  

NLE Websites -- All DOE Office Websites (Extended Search)

Atmospheric Trace Gases » Carbon Isotopes Atmospheric Trace Gases » Carbon Isotopes Carbon Isotopes Gateway Pages to Isotopes Data Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon Dioxide and Carbon-13 in Methane 800,000 Deuterium Record and Shorter Records of Various Isotopic Species from Ice Cores Carbon-13 13C in CO Measurements from Niwot Ridge, Colorado and Montana de Oro, California (Tyler) 13C in CO2 NOAA/CMDL Flask Network (White and Vaughn) CSIRO GASLAB Flask Network (Allison, Francey, and Krummel) CSIRO in situ measurements at Cape Grim, Tasmania (Francey and Allison) Scripps Institution of Oceanography (Keeling et al.) 13C in CH4 NOAA/CMDL Flask Network (Miller and White) Northern & Southern Hemisphere Sites (Quay and Stutsman) Northern & Southern Hemisphere Sites (Stevens)

73

Selective Isotope Determination of Uranium using HR-RIMS  

Science Conference Proceedings (OSTI)

The detection of lowest abundances of the ultra trace isotope {sup 236}U in environmental samples requires an efficient detection method which allows a high elemental and isotopic selectivity to suppress neighbouring isotopes of the same element and other background. High Resolution Laser Resonance Ionization Mass Spectrometry (HR-RIMS) uses the individual electron structure of each isotope to provide an outstanding element and isotope selective ionization.

Raeder, S.; Fies, S.; Wendt, K. D. A. [Institut fuer Physik, Johannes Gutenberg Universitaet Mainz, 55128 Mainz (Germany); Tomita, H. [Nagoya University (Japan)

2009-03-17T23:59:59.000Z

74

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

E-Print Network (OSTI)

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.

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

2009-07-01T23:59:59.000Z

75

from Isotope Production Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

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

76

ISOTOPE SEPARATORS  

DOE Patents (OSTI)

An improvement is presented in the structure of an isotope separation apparatus and, in particular, is concerned with a magnetically operated shutter associated with a window which is provided for the purpose of enabling the operator to view the processes going on within the interior of the apparatus. The shutier is mounted to close under the force of gravity in the absence of any other force. By closing an electrical circuit to a coil mouated on the shutter the magnetic field of the isotope separating apparatus coacts with the magnetic field of the coil to force the shutter to the open position.

Bacon, C.G.

1958-08-26T23:59:59.000Z

77

It's Elemental - Isotopes of the Element Dysprosium  

NLE Websites -- All DOE Office Websites (Extended Search)

Isotopes Mass Number Half-life Decay Mode Branching Percentage 138 No Data Available Electron Capture (suspected) No Data Available 139 0.6 seconds Electron Capture No Data...

78

It's Elemental - Isotopes of the Element Antimony  

NLE Websites -- All DOE Office Websites (Extended Search)

Isotopes Mass Number Half-life Decay Mode Branching Percentage 103 1.5 microseconds Electron Capture (suspected) No Data Available 104 0.44 seconds Electron Capture 100.00%...

79

Improved process for preparing strontium-82 isotope  

DOE Patents (OSTI)

This invention is comprised of a process for making {sup 82}Sr by bombarding a molybdenum target enriched in light-mass molybdenum isotopes with high energy protons resulting in high yield, high purity {sup 82}Sr.

Michaels, G.E.; Beaver, J.E.; Moody, D.C.

1991-12-31T23:59:59.000Z

80

Positive and inverse isotope effect on superconductivity  

E-Print Network (OSTI)

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.

Tian De Cao

2009-09-04T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Measurement of Trace Uranium Isotopes  

Science Conference Proceedings (OSTI)

The extent to which thermal ionization mass spectrometry (TIMS) can measure trace quantities of 233U and 236U in the presence of a huge excess of natural uranium is evaluated. This is an important nuclear non-proliferation measurement. Four ion production methods were evaluated with three mass spectrometer combinations. The most favorable combinations are not limited by abundance sensitivity; rather, the limitations are the ability to generate a uranium ion beam of sufficient intensity to obtain the required number of counts on the minor isotopes in relationship to detector background. The most favorable situations can measure isotope ratios in the range of E10 if sufficient sample intensity is available. These are the triple sector mass spectrometer with porous ion emitters (PIE) and the single sector mass spectrometer with energy filtering.

Matthew G. Watrous; James E. Delmore

2011-05-01T23:59:59.000Z

82

Flow Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope  

Open Energy Info (EERE)

Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope Trends Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Flow Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope Trends Details Activities (5) Areas (5) Regions (0) Abstract: Heat and mass are injected into the shallow crust when mantle fluids are able to flow through the ductile lower crust. Minimum He-3/He-4 ratios in surface fluids from the northern Basin and Range Province, western North America, increase systematically from low crustal values in the east to high mantle values in the west, a regional trend that correlates with the rates of active crustal deformation. The highest ratios occur where the extension and shear strain rates are greatest. The

83

Available Technologies: Nanostructure Initiator Mass Spectrometry ...  

Using time dependent isotopic labeling and mass spectrometry imaging, researchers at Berkeley Lab and the University of California, Berkeley have developed a ...

84

Early Days of Accelerator Mass Spectrometry  

DOE R&D Accomplishments (OSTI)

Alvarez reviews his role in the development of the tandem Van de Graaff accelerator and the technique of accelerator mass spectrometry as a technique for isotope dating. (GHT)

Alvarez, L. W.

1981-05-00T23:59:59.000Z

85

New Enhancements Upgrade NIST Mass Spectra Library  

Science Conference Proceedings (OSTI)

... peaks representing a unique distribution of masses due to isotopes with varying ... with Version 2.0d of the NIST MS Search Program for Windows ...

2013-06-05T23:59:59.000Z

86

Isotope effect in BEDT-TTF based organic superconductors  

SciTech Connect

The results of the comprehensive isotope effect studies, in which seven different isotopically labeled (involving {sup 13}C, {sup 34}S and {sup 2}H labeling) BEDT-TTF derivatives and isotopically labeled anion [Cu({sup 15}N{sup 13}CS){sub 2}]{sup {minus}} were utilized, are summarized. For the first time, convincing evidence for a genuine BCS-like mass isotope effect in an organic superconductor is revealed in these studies.

Kini, A.M.; Carlson, K.D.; Dudek, J.D.; Geiser, U.; Wang, H.H.; Williams, J.M.

1996-10-01T23:59:59.000Z

87

Glossary Term - Isotope  

NLE Websites -- All DOE Office Websites (Extended Search)

Helios Previous Term (Helios) Glossary Main Index Next Term (Joule) Joule Isotope The Three Isotopes of Hydrogen - Protium, Deuterium and Tritium Atoms that have the same number of...

88

Method for separating isotopes  

DOE Patents (OSTI)

Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether complex is extracted from the feed solution, and the isotope is thereafter separated from the cyclic polyether.

Jepson, B.E.

1975-10-21T23:59:59.000Z

89

Stable isotope studies  

SciTech Connect

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.

Ishida, T.

1992-01-01T23:59:59.000Z

90

Analysis of hydrogen isotope mixtures  

DOE Patents (OSTI)

Disclosed are an apparatus and a method for determining 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.

Villa-Aleman, E.

1992-12-31T23:59:59.000Z

91

Analysis of hydrogen isotope mixtures  

DOE Patents (OSTI)

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.

Villa-Aleman, Eliel (Aiken, SC)

1994-01-01T23:59:59.000Z

92

Isotopes: Isotope Production, Medical IsotopesOffice of Science...  

NLE Websites -- All DOE Office Websites (Extended Search)

Managers Put a short description of the graphic or its primary message here Isotope Production and Applications The Los Alamos National Laboratory has produced radioactive...

93

Isotope separation by photochromatography  

DOE Patents (OSTI)

An isotope separation method which comprises physically adsorbing an isotopically mixed molecular species on an adsorptive surface and irradiating the adsorbed molecules with radiation of a predetermined wavelength which will selectively excite a desired isotopic species. Sufficient energy is transferred to the excited molecules to desorb them from the surface and thereby separate them from the unexcited undesired isotopic species. The method is particularly applicable to the separation of hydrogen isotopes.

Suslick, Kenneth S. (Stanford, CA)

1977-01-01T23:59:59.000Z

94

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Science Conference Proceedings (OSTI)

[an error occurred while processing this directive] ... Thus, many systems administrators do not regularly update non ... works well but it does not protect ...

95

[an error occurred while processing this directive  

Science Conference Proceedings (OSTI)

[an error occurred while processing this directive] These are ... of commercial products within NIST web pages is for information only; it does not imply ...

96

Isotope Enrichment Calculator  

Science Conference Proceedings (OSTI)

... incremental isotopic percentages which are compared with an input experimentally derived profile. The theoretical profile of 15 N percentage which ...

2012-10-09T23:59:59.000Z

97

Naturally Occurring Radioactive Materials in Cargo at US Borders  

Science Conference Proceedings (OSTI)

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)

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

98

Isotopically controlled semiconductors  

SciTech Connect

Semiconductor bulk crystals and multilayer structures with controlled isotopic composition have attracted much scientific and technical interest in the past few years. Isotopic composition affects a large number of physical properties, including phonon energies and lifetimes, bandgaps, the thermal conductivity and expansion coefficient and spin-related effects. Isotope superlattices are ideal media for self-diffusion studies. In combination with neutron transmutation doping, isotope control offers a novel approach to metal-insulator transition studies. Spintronics, quantum computing and nanoparticle science are emerging fields using isotope control.

Haller, Eugene E.

2001-12-21T23:59:59.000Z

99

ISOTOPE CONVERSION DEVICE  

DOE Patents (OSTI)

This patent relates to nuclear reactors of tbe type utilizing a liquid fuel and designed to convert a non-thermally fissionable isotope to a thermally fissionable isotope by neutron absorption. A tank containing a reactive composition of a thermally fissionable isotope dispersed in a liquid moderator is disposed within an outer tank containing a slurry of a non-thermally fissionable isotope convertible to a thermally fissionable isotope by neutron absorption. A control rod is used to control the chain reaction in the reactive composition and means are provided for circulating and cooling the reactive composition and slurry in separate circuits.

Wigner, E.P.; Young, G.J.; Ohlinger, L.A.

1957-12-01T23:59:59.000Z

100

ARM - Measurement - Isotope ratio  

NLE Websites -- All DOE Office Websites (Extended Search)

govMeasurementsIsotope ratio govMeasurementsIsotope ratio ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Isotope ratio Ratio of stable isotope concentrations. Categories Atmospheric Carbon, Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments FLASK : Flask Samplers for Carbon Cycle Gases and Isotopes Field Campaign Instruments FLASK : Flask Samplers for Carbon Cycle Gases and Isotopes Datastreams FLASK : Flask Samplers for Carbon Cycle Gases and Isotopes

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

VELOCITY SELECTOR METHOD FOR THE SEPARATION OF ISOTOPES  

DOE Patents (OSTI)

A velocity selector apparatus is described for separating and collecting an enriched fraction of the isotope of a particular element. The invention has the advantage over conventional mass spectrometers in that a magnetic field is not used, doing away with the attendant problems of magnetic field variation. The apparatus separates the isotopes by selectively accelerating the ionized constituents present in a beam of the polyisotopic substance that are of uniform kinetic energy, the acceleration being applied intermittently and at spaced points along the beam and in a direction normal to the direction of the propagation of the uniform energy beam whereby a transverse displacement of the isotopic constituents of different mass is obtained.

Britten, R.J.

1957-12-31T23:59:59.000Z

102

RADIATION PROTECTION AND DECONTAMINATION IN ISOTOPE LABORATORIES  

SciTech Connect

An accident trolley is described that contains everything needed if an accident with radioactive materials occurs. Instructions for decontamination are given and measures to be taken after mishaps with open isotopes are recommended. Cleansing and treatment of laundry that is contaminated with radioactive materials are discussed and an active laundry is described. (auth)

Schanze, U.O.

1963-12-01T23:59:59.000Z

103

Time-of-Flight Mass Measurements of Exotic Nuclei  

Science Conference Proceedings (OSTI)

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.

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

104

Accelerator mass spectrometry as a bioanalytical tool for nutritional research  

SciTech Connect

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.

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

1997-09-01T23:59:59.000Z

105

HYDROGEN ISOTOPE TARGETS  

DOE Patents (OSTI)

The design of targets for use in the investigation of nuclear reactions of hydrogen isotopes by bombardment with accelerated particles is described. The target con struction eomprises a backing disc of a metal selected from the group consisting of molybdenunn and tungsten, a eoating of condensed titaniunn on the dise, and a hydrogen isotope selected from the group consisting of deuterium and tritium absorbed in the coatiag. The proeess for preparing these hydrogen isotope targets is described.

Ashley, R.W.

1958-08-12T23:59:59.000Z

106

Hybrid isotope separation scheme  

DOE Patents (OSTI)

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.

Maya, Jakob (Brookline, MA)

1991-01-01T23:59:59.000Z

107

Laser isotope separation by multiple photon absorption  

DOE Patents (OSTI)

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, in 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.

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)

1977-01-01T23:59:59.000Z

108

Laser isotope separation by multiple photon absorption  

DOE Patents (OSTI)

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.

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

109

Discovery of the Mercury Isotopes  

E-Print Network (OSTI)

Forty mercury 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.

D. Meierfrankenfeld; M. Thoennessen

2009-12-01T23:59:59.000Z

110

Isotopic Analysis | Open Energy Information  

Open Energy Info (EERE)

Structural: Hydrological: Source of fluids, circulation, andor mixing. Thermal: Heat source and general reservoir temperatures Dictionary.png Isotopic Analysis: Isotopes...

111

Fuel Cycle and Isotopes Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Divisions Fuel Cycle and Isotopes Division Jeffrey Binder, Division Director Jeffrey Binder, Division Director The Fuel Cycle and Isotopes Division (FCID) of the Nuclear Science...

112

Isotope Enrichment | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Modern electromagnetic isotope separator developed and being scaled-up to replace the Manhattan Project-era Calutrons used for stable isotope enrichment. Since 1945, ORNL has...

113

Isotope GeochemistryIsotope Geochemistry Isotopes do not fractionate during partial  

E-Print Network (OSTI)

/204Pb, 207Pb/204Pb, due to U and Th decay The isotope geology of PbThe isotope geology of Pb #12;The isotope geology of PbThe isotope geology of Pb µ = 238U/204Pb Primeval lead (Isotope ratios of Pb tT t eea Pb Pb -µ+= 30.90 204 206 == a Pb Pb i 29.100 204 207 == b Pb Pb i #12;The isotope geology

Siebel, Wolfgang

114

Introduction to naturally occurring radioactive material  

SciTech Connect

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.

Egidi, P.

1997-08-01T23:59:59.000Z

115

Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs Area (White,  

Open Energy Info (EERE)

Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs Area (White, Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs Area (White, Et Al., 1992) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs Area (White, Et Al., 1992) Exploration Activity Details Location Valles Caldera - Sulphur Springs Area Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness not indicated DOE-funding Unknown Notes Used various geochemical techniques to obtain data from which information regarding mass transfer rates. This then led to conclucions of the history/evolution of the geothermal system. Unclear whether useful for exploration purposes. References Art F. White, Nancy J. Chuma, Fraser Goff (1992) Mass Transfer Constraints On The Chemical Evolution Of An Active Hydrothermal System,

116

Enforcement Letter, International Isotopes Idaho Inc - August 20, 1999 |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

International Isotopes Idaho Inc - August 20, International Isotopes Idaho Inc - August 20, 1999 Enforcement Letter, International Isotopes Idaho Inc - August 20, 1999 August, 20, 1999 Issued to International Isotopes Idaho, Inc. related to the Relocation of an Irradiated Pellet at the Test Reactor Area Hot Cell Facility at the Idaho National Engineering and Environmental Laboratory This letter refers to the Department of Energy's (DOE) evaluation of the facts and circumstances concerning the relocation of an irradiated [isotope] pellet from within a hot cell to an adjoining, outside, charging port service area. This incident occurred on January 6, 1999, at the Idaho National Engineering and Environmental Laboratory's Test Reactor Area Hot Cell Facility (TRA-632). Building TRA-632 is utilized by International

117

Enforcement Letter, International Isotopes Idaho Inc - August 20, 1999 |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

International Isotopes Idaho Inc - August 20, International Isotopes Idaho Inc - August 20, 1999 Enforcement Letter, International Isotopes Idaho Inc - August 20, 1999 August, 20, 1999 Issued to International Isotopes Idaho, Inc. related to the Relocation of an Irradiated Pellet at the Test Reactor Area Hot Cell Facility at the Idaho National Engineering and Environmental Laboratory This letter refers to the Department of Energy's (DOE) evaluation of the facts and circumstances concerning the relocation of an irradiated [isotope] pellet from within a hot cell to an adjoining, outside, charging port service area. This incident occurred on January 6, 1999, at the Idaho National Engineering and Environmental Laboratory's Test Reactor Area Hot Cell Facility (TRA-632). Building TRA-632 is utilized by International

118

Isotopically controlled semiconductors  

SciTech Connect

The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

Haller, Eugene E.

2006-06-19T23:59:59.000Z

119

Method for isotopic analysis of chlorinated organic compounds  

DOE Patents (OSTI)

The present invention provides a method for preparing a VOC sample for carbon and chlorine isotope ratio analysis by mass spectrometer. A VOC sample is placed in a combustion tube and reacted with CuO to form CO.sub.2 and CuCl. The CO.sub.2 is then extracted and analyzed for the carbon isotope ratio. The CuCl is separated from the excess CuO and reacted with CH.sub.3 I to form CH.sub.3 Cl, extracted and analyzed for chlorine isotope ratio.

Holt, Ben D. (Hindsdale, IL); Sturchio, Neil C. (Oswego, IL)

1999-01-01T23:59:59.000Z

120

Strategic Isotope Production | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Strategic Isotope Production SHARE Strategic Isotope Production ORNL's unique facilities at the High Flux Isotope Reactor (HFIR), Radiochemical Engineering Development Center...

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Isotopes as Environmental Tracers in Archived Biological ...  

Science Conference Proceedings (OSTI)

... Tissue Archival and Monitoring Program (STAMP ... and isotopes) and carbon/nitrogen (isotopes). The carbon/nitrogen isotope data provide valuable ...

2012-10-02T23:59:59.000Z

122

Separation of sulfur isotopes  

DOE Patents (OSTI)

Sulfur isotopes are continuously separated and enriched using a closed loop reflux system wherein sulfur dioxide (SO.sub.2) is reacted with sodium hydroxide (NaOH) or the like to form sodium hydrogen sulfite (NaHSO.sub.3). Heavier sulfur isotopes are preferentially attracted to the NaHSO.sub.3, and subsequently reacted with sulfuric acid (H.sub.2 SO.sub.4) forming sodium hydrogen sulfate (NaHSO.sub.4) and SO.sub.2 gas which contains increased concentrations of the heavier sulfur isotopes. This heavy isotope enriched SO.sub.2 gas is subsequently separated and the NaHSO.sub.4 is reacted with NaOH to form sodium sulfate (Na.sub.2 SO.sub.4) which is subsequently decomposed in an electrodialysis unit to form the NaOH and H.sub.2 SO.sub.4 components which are used in the aforesaid reactions thereby effecting sulfur isotope separation and enrichment without objectionable loss of feed materials.

DeWitt, Robert (Centerville, OH); Jepson, Bernhart E. (Dayton, OH); Schwind, Roger A. (Centerville, OH)

1976-06-22T23:59:59.000Z

123

Stable Isotopes in Hailstones. Part I: The Isotopic Cloud Model  

Science Conference Proceedings (OSTI)

Equations describing the isotopic balance between five water species (vapor, cloud water, rainwater, cloud ice and graupel)have been incorporated into a one-dimensional steady-state cloud model. The isotope contents of the various water ...

B. Federer; N. Brichet; J. Jouzel

1982-06-01T23:59:59.000Z

124

Isotopic identification of leakage gas from underground storage reservoirs. Progress report  

SciTech Connect

The Illinois State Geological Survey reports that in areas where bacteriogenic methane occurs in the near-surface groundwater, isotopic analysis of methane reliably distinguishes this gas from gas that has leaked from underground storage reservoirs. Bacteriogenic methane generally has an isotopic-carbon composition of -64 to -90 per mil, whereas the pipeline and reservoir gases analyzed thus far have all had isotopic-carbon compositions in the range of -40 to -46 per mil.

Coleman, D.D.; Meents, W.F.; Liu, C.L.; Keogh, R.A.

1977-01-01T23:59:59.000Z

125

ISOTOPE SEPARATION AND ISOTOPE EXCHANGE. A Bibliography with Abstracts  

SciTech Connect

The unclassified literature covering 2498 reports from 1907 through 1957 has been searched for isotopic exchange and isotepic separation reactions involving U and the lighter elements of the periodic chart through atomic number 30. From 1953 to 1957, all elements were included Numerous references to isotope properties, isotopic ratios, and kinetic isotope effects were included. This is a complete revision of TID-3036 (Revised) issued June 4, 1954. An author index is included. (auth)

Begun, G.M.

1959-10-28T23:59:59.000Z

126

A direct and rapid leaf water extraction method for isotopic analysis  

E-Print Network (OSTI)

technique based on centrifugation/filtration of leaf samples pulverised in their original sampling tubes for isotopic analysis via pyrolysis gas chromatography isotope ratio mass spectrometry (PYR/GC/IRMS). The new of the centrifuge(s) used. This method provides a rapid, low-cost and reliable alternative to conventional vacuum

Yakir, Dan

127

Method for detecting and correcting for isotope burn-in during long-term neutron dosimetry exposure  

DOE Patents (OSTI)

A method is described for detecting and correcting for isotope burn-in during-long term neutron dosimetry exposure. In one embodiment, duplicate pairs of solid state track recorder fissionable deposits are used, including a first, fissionable deposit of lower mass to quantify the number of fissions occuring during the exposure, and a second deposit of higher mass to quantify the number of atoms of for instance .sup.239 Pu by alpha counting. In a second embodiment, only one solid state track recorder fissionable deposit is used and the resulting higher track densities are counted with a scanning electron microscope. This method is also applicable to other burn-in interferences, e.g., .sup.233 U in .sup.232 Th or .sup.238 Pu in .sup.237 Np.

Ruddy, Francis H. (Monroeville, PA)

1988-01-01T23:59:59.000Z

128

Selection of Isotopes and Elements for Fuel Cycle Analysis  

Science Conference Proceedings (OSTI)

Fuel cycle system analysis simulations examine how the selection among fuel cycle options for reactors, fuel, separation, and waste management impact uranium ore utilization, waste masses and volumes, radiotoxicity, heat to geologic repositories, isotope-dependent proliferation resistance measures, and so forth. Previously, such simulations have tended to track only a few actinide and fission product isotopes, those that have been identified as important to a few criteria from the standpoint of recycled material or waste, taken as a whole. After accounting for such isotopes, the residual mass is often characterized as “fission product other” or “actinide other”. However, detailed assessment of separation and waste management options now require identification of key isotopes and residual mass for Group 1A/2A elements (Rb, Cs, Sr, Ba), inert gases (Kr, Xe), halogens (Br, I), lanthanides, transition metals, transuranic (TRU), uranium, actinide decay products. The paper explains the rationale for a list of 81 isotopes and chemical elements to better support separation and waste management assessment in dynamic system analysis models such as Verifiable Fuel Cycle Simulation (VISION)

Steven J. Piet

2009-04-01T23:59:59.000Z

129

DEEP WATER ISOTOPIC CURRENT ANALYZER  

DOE Patents (OSTI)

A deepwater isotopic current analyzer, which employs radioactive isotopes for measurement of ocean currents at various levels beneath the sea, is described. The apparatus, which can determine the direction and velocity of liquid currents, comprises a shaft having a plurality of radiation detectors extending equidistant radially therefrom, means for releasing radioactive isotopes from the shaft, and means for determining the time required for the isotope to reach a particular detector. (AEC)

Johnston, W.H.

1964-04-21T23:59:59.000Z

130

LITERATURE SURVEY ON ISOTOPIC ABUNDANCE RATIO MEASUREMENTS - 2001-2005  

Science Conference Proceedings (OSTI)

Along with my usual weekly review of the published literature for new nuclear data, I also search for new candidates for best measurements of isotopic abundances from a single source. Most of the published articles, that I previously had found in the Research Library at the Brookhaven Lab, have already been sent to the members of the Atomic Weights Commission, by either Michael Berglund or Thomas Walczyk. In the last few days, I checked the published literature for any other articles in the areas of natural variations in isotopic abundance ratios, measurements of isotopic abundance ratios on samples of extra-terrestrial material and isotopic abundance ratio measurements performed using ICPMS instruments. Hopefully this information will be of interest to members of the Commission, the sub-committee on isotopic abundance measurements (SIAM), members of the former sub-committee on natural isotopic fractionation (SNIF), the sub-committee on extra-terrestrial isotope ratios (SETIR), the RTCE Task Group and the Guidelines Task Group, who are dealing with ICPMS and TIMS comparisons. In the following report, I categorize the publications in one of four areas. Measurements performed using either positive or negative ions with Thermal Ionization Mass Spectrometer, TIMS, instruments; measurements performed on Inductively Coupled Plasma Mass Spectrometer, ICPMS, instruments; measurements of natural variations of the isotopic abundance ratios; and finally measurements on extra-terrestrial samples with instrumentation of either type. There is overlap in these areas. I selected out variations and ET results first and then categorized the rest of the papers by TIMS and ICPMS.

HOLDEN, N.E.

2005-08-13T23:59:59.000Z

131

Method for separating boron isotopes  

SciTech Connect

A method of separating boron isotopes .sup.10 B and .sup.11 B by laser-induced selective excitation and photodissociation of BCl.sub.3 molecules containing a particular boron isotope. The photodissociation products react with an appropriate chemical scavenger and the reaction products may readily be separated from undissociated BCl.sub.3, thus effecting the desired separation of the boron isotopes.

Rockwood, Stephen D. (Los Alamos, NM)

1978-01-01T23:59:59.000Z

132

Molecular isotopic effects on coupled electronic and nuclear fluxes  

SciTech Connect

A full quantum treatment shows that coupled electronic and nuclear fluxes exhibit a strong sensitivity to a small mass change in a vibrating molecule. This has been exemplified with the existing isotopes of H{sub 2}{sup +} as well as few fictitious ones. We find that the fluxes undergo a significant change as one goes from one isotope of reduced mass {mu} to another. Other well-defined observables are likewise affected. It turns out that as a general rule, the heavier the isotope, the larger the flux, the smaller the dispersion, and the longer the revival period. While we were able to confirm analytically that the time at the first turning point scales as {radical}({mu}) and that the revival period changes linearly with {mu}, the mechanism of other observables remains subtle as the result of quantum interference highlighted by the pronounced difference observed on the dispersion pattern.

Kenfack, A.; Paulus, B. [Physikalische und Theoretische Chemie, Institut fuer Chemie und Biochemie, Freie Universitaet Berlin, D-14195 Berlin (Germany); Barth, I. [Physikalische und Theoretische Chemie, Institut fuer Chemie und Biochemie, Freie Universitaet Berlin, D-14195 Berlin (Germany); Max-Born-Institut, Max-Born-Strasse 2A, D-12489 Berlin (Germany); Marquardt, F. [Visualisierung und Datenanalyse, Zuse Institut Berlin, D-14195 Berlin (Germany); Fachbereich Mathematik, Freie Universitaet Berlin, D-14195 Berlin (Germany)

2010-12-15T23:59:59.000Z

133

Sensitive dependence of isotope and isobar distribution of limiting temperatures on symmetry energy  

E-Print Network (OSTI)

The mass, isotope and isobar distributions of limiting temperature for finite nuclei are investigated by thermodynamics approach with the Skyrme energy density functional. The calculations show there is an exact corresponding relationship between the width of isotope and isobar distribution of limiting temperatures and the stiffness of the density dependence of symmetry energy. The symmetry energy with smaller slope parameter $L_{\\rm{sym}}$ provides a wider distribution of limiting temperatures of nuclei in the isotope and isobar chain. Our studies show that the widths of isotope and isobar distribution of limiting temperatures are useful to obtain the information of the density dependence of the symmetry energy at finite temperature.

Li Ou; Min Liu; Zhuxia Li

2013-10-14T23:59:59.000Z

134

Negative mass  

E-Print Network (OSTI)

Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analyzed. Other surprising effects include the bizarre system of negative mass chasing positive pass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given.

Richard T Hammond

2013-08-06T23:59:59.000Z

135

Final Report "Structure of Rare Isotopes"  

SciTech Connect

The Junior Investigator grant 'Structure of Rare Isotopes' (DE-FG02-07ER41529) supported research in low-energy nuclear theory from September 1, 2007 to August 31, 2010. It was the main goal of the proposed research to develop and optimize an occupation-number-based energy functional for the computation of nuclear masses, and this aim has been reached. Furthermore, progress was made in linking two and three-body forces from low-momentum interactions to pairing properties in nuclear density functionals, and in the description of deformed nuclei within an effective theory.

Papenbrock, Thomas

2012-05-09T23:59:59.000Z

136

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

SciTech Connect

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.

Snider, J.D.

1996-02-01T23:59:59.000Z

137

Neutrino mass, a status report  

SciTech Connect

Experimental approaches to neutrino mass include kinematic mass measurements, neutrino oscillation searches at rectors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indications that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing.

Robertson, R.G.H.

1993-08-01T23:59:59.000Z

138

First AID (Atom counting for Isotopic Determination).  

SciTech Connect

Los Alamos National Laboratory (LANL) has established an in vitro bioassay monitoring program in compliance with the requirements in the Code of Federal Regulations, 10 CFR 835, Occupational Radiation Protection. One aspect of this program involves monitoring plutonium levels in at-risk workers. High-risk workers are monitored using the ultra-sensitive Therrnal Ionization Mass Spectrometry (TIMS) technique to ensure compliance with DOE standards. TIMS is used to measure atom ratios of 239Pua nd 240Puw ith respect to a tracer isotope ('Pu). These ratios are then used to calculate the amount of 239Pu and 240Pup resent. This low-level atom counting technique allows the calculation of the concentration levels of 239Pu and 240Pu in urine for at risk workers. From these concentration levels, dose assessments can be made and worker exposure levels can be monitored. Detection limits for TIMS analysis are on the order of millions of atoms, which translates to activity levels of 150 aCi 239Pua nd 500 aCi for 240Pu. pCi for Our poster presentation will discuss the ultra-sensitive, low-level analytical technique used to measure plutonium isotopes and the data verification methods used for validating isotopic measurements.

Roach, J. L. (Jeffrey L.); Israel, K. M. (Kimberly M.); Steiner, R. E. (Robert E.); Duffy, C. J. (Clarence J.); Roench, F. R. (Fred R.)

2002-01-01T23:59:59.000Z

139

Isotopic ratio method for determining uranium contamination  

SciTech Connect

The presence of high concentrations of uranium in the subsurface can be attributed either to contamination from uranium processing activities or to naturally occurring uranium. A mathematical method has been employed to evaluate the isotope ratios from subsurface soils at the Rocky Flats Nuclear Weapons Plant (RFP) and demonstrates conclusively that the soil contains uranium from a natural source and has not been contaminated with enriched uranium resulting from RFP releases. This paper describes the method used in this determination which has widespread application in site characterizations and can be adapted to other radioisotopes used in manufacturing industries. The determination of radioisotope source can lead to a reduction of the remediation effort.

Miles, R.E.; Sieben, A.K.

1994-02-03T23:59:59.000Z

140

Assessment of methods for analyzing gaseous mixtures of hydrogen isotopes and helium  

DOE Green Energy (OSTI)

Mass spectrographic methods have served well in the past to analyze gaseous mixtures of the hydrogen isotopes. Alternate methods of analyses are reviewed which offer wider ranges and variety of isotopic determinations. This report describes possible improvements of the mass spectrographic determinations, gas chromatography, anti-Stokes Raman spectroscopy, microwave-induced optical emission spectroscopy, and methods of measuring tritium using radiation detection devices. Precision, accuracy, limitations, and costs are included for some of the methods mentioned. Costs range from $70,000 for the anti-Stokes Raman spectroscopy equipment, which can determine hydrogen isotopes but not helium, to less than $10,000 for the gas chromatographic equipment, which can determine hydrogen isotopes and helium with precision and accuracy comparable to those of the mass spectrometer.

Attalla, A.; Bishop, C.T.; Bohl, D.R.; Buxton, T.L.; Sprague, R.E.; Warner, D.K.

1976-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

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

Science Conference Proceedings (OSTI)

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.

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

2011-06-15T23:59:59.000Z

142

Mass Measurements  

Science Conference Proceedings (OSTI)

... NIST maintains the national standard for mass in the form of the prototype kilogram (K20) and provides services to support the parts of the national ...

2013-06-28T23:59:59.000Z

143

fehlende Masse  

NLE Websites -- All DOE Office Websites (Extended Search)

beim radioaktiven Zerfall mit der fehlenden Masse?" Zur Erinnerung: wenn Uran in Thorium und ein alpha Teilchen zerfllt, dann gehen 0.0046 u (Masseneinheiten) der...

144

Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts  

DOE Green Energy (OSTI)

Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{sub 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.

Krishna, K.R.

1992-01-01T23:59:59.000Z

145

Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO{sub 2} catalysts  

DOE Green Energy (OSTI)

Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{sub 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.

Krishna, K.R.

1992-01-01T23:59:59.000Z

146

Isotopically labeled compositions and method  

DOE Patents (OSTI)

Compounds having stable isotopes .sup.13C and/or .sup.2H were synthesized from precursor compositions having solid phase supports or affinity tags.

Schmidt, Jurgen G. (Los Alamos, NM); Kimball, David B. (Los Alamos, NM); Alvarez, Marc A. (Santa Fe, NM); Williams, Robert F. (Los Alamos, NM); Martinez, Rudolfo A. (Santa Fe, NM)

2011-07-12T23:59:59.000Z

147

Atom probe microscopy of three-dimensional distribution of silicon isotopes in {sup 28}Si/{sup 30}Si isotope superlattices with sub-nanometer spatial resolution  

Science Conference Proceedings (OSTI)

Laser-assisted atom probe microscopy of 2 nm period {sup 28}Si/{sup 30}Si isotope superlattices (SLs) is reported. Three-dimensional distributions of {sup 28}Si and {sup 30}Si stable isotopes are obtained with sub-nanometer spatial resolution. The depth resolution of the present atom probe analysis is much higher than that of secondary ion mass spectrometry (SIMS) even when SIMS is performed with a great care to reduce the artifact due to atomic mixing. Outlook of Si isotope SLs as ideal depth scales for SIMS and three-dimensional position standards for atom probe microscopy is discussed.

Shimizu, Yasuo; Kawamura, Yoko; Uematsu, Masashi; Itoh, Kohei M. [School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Tomita, Mitsuhiro [Corporate Research and Development Center, Toshiba Corporation, 8 Shinsugita-cho, Isogo-ku, Yokohama 235-8522 (Japan); Sasaki, Mikio; Uchida, Hiroshi; Takahashi, Mamoru [Toshiba Nanoanalysis Corporation, 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki 212-8583 (Japan)

2009-10-01T23:59:59.000Z

148

Radioactive Mineral Occurences in Nevada | Open Energy Information  

Open Energy Info (EERE)

Radioactive Mineral Occurences in Nevada Radioactive Mineral Occurences in Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Radioactive Mineral Occurences in Nevada Abstract Abstract unavailable. Author Larry J. Garside Organization Nevada Bureau of Mines and Geology Published Nevada Bureau of Mines and Geology, 1973 Report Number Open File Report 94-2 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Radioactive Mineral Occurences in Nevada Citation Larry J. Garside (Nevada Bureau of Mines and Geology). 1973. Radioactive Mineral Occurences in Nevada. Reno, NV: Nevada Bureau of Mines and Geology. Report No.: Open File Report 94-2. Retrieved from "http://en.openei.org/w/index.php?title=Radioactive_Mineral_Occurences_in_Nevada&oldid=690513"

149

ISOTOPE FRACTIONATION PROCESS  

DOE Patents (OSTI)

A new method is described for isotopic enrichment of uranium. It has been found that when an aqueous acidic solution of ionic tetravalent uraniunn is contacted with chelate complexed tetravalent uranium, the U/sup 238/ preferentially concentrates in the complexed phase while U/sup 235/ concentrates in the ionic phase. The effect is enhanced when the chelate compound is water insoluble and is dissolved in a water-immiscible organic solvent. Cupferron is one of a number of sultable complexing agents, and chloroform is a suitable organic solvent.

Clewett, G.H.; Lee, DeW.A.

1958-05-20T23:59:59.000Z

150

Chromatographic hydrogen isotope separation  

DOE Patents (OSTI)

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.

Aldridge, Frederick T. (Livermore, CA)

1981-01-01T23:59:59.000Z

151

Determination of Actinide Isotope Ratios Using Glow Discharge Optogalvanic Spectroscopy  

SciTech Connect

Diode-laser excited optogalvanic spectroscopy (OGS) of a glow discharge has been utilized to measure U-235/U-235 + U-238 isotope ratios. This ``optical mass spectrometric`` measurement has been demonstrated for a number of samples including uranium oxide, fluoride, and metal. Various diode-laser accessible atomic transitions in the 775 to 835 nm region have been evaluated; these transitions were chosen by considering OGS sensitivity and isotope shift. Using the 831.84 nm uranium line, for example, it was possible to measure the U-235/U-235 + U-238 isotope ratio (0.0026) of depleted uranium samples. A prototypical field instrument to make these measurements has been assembled and demonstrated. A U-236 spectral line was identified in a sample of enriched uranium, and an abundance sensitivity was measured.

Young, J.P.; Shaw, R.W.; Barshick, C.M.; Ramsey, J.M.

1997-08-01T23:59:59.000Z

152

Quantification of neptunium by isotope dilution mass spectrometry  

SciTech Connect

A surface ionization-diffusion-type ionization source that uses a rhenium filament overplated with platinum has been developed and optimized for 0.1-ng neptunium samples. This source is capable of measuring the neptunium content of nuclear-test-debris samples to 0.15% precision at the 95% confidence level. 14 refs., 3 figs., 3 tabs.

Efurd, D.W.; Drake, J.; Roensch, F.R.; Cappis, J.H.; Perrin, R.E.

1986-05-01T23:59:59.000Z

153

Isotopic Analysis- Fluid | Open Energy Information  

Open Energy Info (EERE)

Isotopic Analysis- Fluid Isotopic Analysis- Fluid Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Isotopic Analysis- Fluid Details Activities (61) Areas (32) Regions (6) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Fluid Lab Analysis Parent Exploration Technique: Fluid Lab Analysis Information Provided by Technique Lithology: Water rock interaction Stratigraphic/Structural: Hydrological: Origin of hydrothermal fluids; Mixing of hydrothermal fluids Thermal: Isotopic ratios can be used to characterize and locate subsurface thermal anomalies. Dictionary.png Isotopic Analysis- Fluid: Isotopes are atoms of the same element that have different numbers of neutrons. An isotopic analysis looks at a particular isotopic element(s) in

154

It's Elemental - Isotopes of the Element Neptunium  

NLE Websites -- All DOE Office Websites (Extended Search)

Uranium Previous Element (Uranium) The Periodic Table of Elements Next Element (Plutonium) Plutonium Isotopes of the Element Neptunium Click for Main Data Most of the isotope...

155

It's Elemental - Isotopes of the Element Sulfur  

NLE Websites -- All DOE Office Websites (Extended Search)

Phosphorus Previous Element (Phosphorus) The Periodic Table of Elements Next Element (Chlorine) Chlorine Isotopes of the Element Sulfur Click for Main Data Most of the isotope...

156

It's Elemental - Isotopes of the Element Argon  

NLE Websites -- All DOE Office Websites (Extended Search)

Chlorine Previous Element (Chlorine) The Periodic Table of Elements Next Element (Potassium) Potassium Isotopes of the Element Argon Click for Main Data Most of the isotope data...

157

It's Elemental - Isotopes of the Element Ruthenium  

NLE Websites -- All DOE Office Websites (Extended Search)

Technetium Previous Element (Technetium) The Periodic Table of Elements Next Element (Rhodium) Rhodium Isotopes of the Element Ruthenium Click for Main Data Most of the isotope...

158

It's Elemental - Isotopes of the Element Molybdenum  

NLE Websites -- All DOE Office Websites (Extended Search)

Niobium Previous Element (Niobium) The Periodic Table of Elements Next Element (Technetium) Technetium Isotopes of the Element Molybdenum Click for Main Data Most of the isotope...

159

It's Elemental - Isotopes of the Element Thorium  

NLE Websites -- All DOE Office Websites (Extended Search)

Table of Elements Next Element (Protactinium) Protactinium Isotopes of the Element Thorium Click for Main Data Most of the isotope data on this site has been obtained from...

160

It's Elemental - Isotopes of the Element Protactinium  

NLE Websites -- All DOE Office Websites (Extended Search)

Thorium Previous Element (Thorium) The Periodic Table of Elements Next Element (Uranium) Uranium Isotopes of the Element Protactinium Click for Main Data Most of the isotope data...

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

High-Precision Isotopic Reference Materials  

Science Conference Proceedings (OSTI)

... sources, is now capable of measuring isotope ratios with ... revolution in the use of isotopes by revealing ... This program will have an impact in several ...

2012-10-22T23:59:59.000Z

162

The marine biogeochemistry of zinc isotopes  

E-Print Network (OSTI)

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, ...

John, Seth G

2007-01-01T23:59:59.000Z

163

Method of separating boron isotopes  

SciTech Connect

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.

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

164

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

E-Print Network (OSTI)

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.

Sakshi Gautam; Aman Deep Sood

2011-02-13T23:59:59.000Z

165

Silicon Isotopic Fractionation of CAI-like Vacuum Evaporation Residues  

SciTech Connect

Calcium-, aluminum-rich inclusions (CAIs) are often enriched in the heavy isotopes of magnesium and silicon relative to bulk solar system materials. It is likely that these isotopic enrichments resulted from evaporative mass loss of magnesium and silicon from early solar system condensates while they were molten during one or more high-temperature reheating events. Quantitative interpretation of these enrichments requires laboratory determinations of the evaporation kinetics and associated isotopic fractionation effects for these elements. The experimental data for the kinetics of evaporation of magnesium and silicon and the evaporative isotopic fractionation of magnesium is reasonably complete for Type B CAI liquids (Richter et al., 2002, 2007a). However, the isotopic fractionation factor for silicon evaporating from such liquids has not been as extensively studied. Here we report new ion microprobe silicon isotopic measurements of residual glass from partial evaporation of Type B CAI liquids into vacuum. The silicon isotopic fractionation is reported as a kinetic fractionation factor, {alpha}{sub Si}, corresponding to the ratio of the silicon isotopic composition of the evaporation flux to that of the residual silicate liquid. For CAI-like melts, we find that {alpha}{sub Si} = 0.98985 {+-} 0.00044 (2{sigma}) for {sup 29}Si/{sup 28}Si with no resolvable variation with temperature over the temperature range of the experiments, 1600-1900 C. This value is different from what has been reported for evaporation of liquid Mg{sub 2}SiO{sub 4} (Davis et al., 1990) and of a melt with CI chondritic proportions of the major elements (Wang et al., 2001). There appears to be some compositional control on {alpha}{sub Si}, whereas no compositional effects have been reported for {alpha}{sub Mg}. We use the values of {alpha}Si and {alpha}Mg, to calculate the chemical compositions of the unevaporated precursors of a number of isotopically fractionated CAIs from CV chondrites whose chemical compositions and magnesium and silicon isotopic compositions have been previously measured.

Knight, K; Kita, N; Mendybaev, R; Richter, F; Davis, A; Valley, J

2009-06-18T23:59:59.000Z

166

Quantum instanton evaluation of the kinetic isotope effects  

DOE Green Energy (OSTI)

A general quantum-mechanical method for computing kinetic isotope effects is presented. The method is based on the quantum instanton approximation for the rate constant and on the path integral Metropolis Monte-Carlo evaluation of the Boltzmann operator matrix elements. It computes the kinetic isotope effect directly, using a thermodynamic integration with respect to the mass of the isotope, thus avoiding the more computationally expensive process of computing the individual rate constants. The method is more accurate than variational transition-state theories or the semiclassical instanton method since it does not assume a single reaction path and does not use a semiclassical approximation of the Boltzmann operator. While the general Monte-Carlo implementation makes the method accessible to systems with a large number of atoms, we present numerical results for the Eckart barrier and for the collinear and full three-dimensional isotope variants of the hydrogen exchange reaction H+H{sub 2} {yields} H{sub 2}+H. In all seven test cases, for temperatures between 250 K and 600 K, the error of the quantum instanton approximation for the kinetic isotope effects is less than {approx}10%.

Vanicek, Jiri; Miller, William H.; Castillo, Jesus F.; Aoiz, F.Javier

2005-04-19T23:59:59.000Z

167

Isotope effect study of {kappa}-(BEDT-TTF){sub 2}Cu(NCS){sub 2}: Labeling in the anion  

SciTech Connect

Since the initial discovery of organic superconductivity in 1979, a large number of organic superconductors have now been synthesized. However, the mechanism of electron-pairing in these novel superconductors has remained largely unresolved. Isotope effect studies constitute an important experimental tool for the investigation of whether or not the electron-pairing mechanism in organic superconductors is phonon-mediated, as in conventional superconductors. Recent isotope effect studies in the authors` laboratory, involving seven different isotopically labeled BEDT-TTF (or ET) derivatives, have demonstrated the following: (1) intramolecular phonon modes involving C{double_bond}C and C{single_bond}S stretching vibrations in the ET donor molecule are not the dominant mediators of electron-pairing, and (2) in {kappa}-(ET){sub 2}Cu(NCS){sub 2}, there exist two competing isotope effects--a normal mass effect, i.e., lowering of {Tc} upon isotopic labeling, when the ET molecular mass is increased by concurrent {sup 13}C and {sup 34}S labeling, in addition to an inverse isotope effect upon deuterium labeling in ET. It is of great interest to investigate if there is an isotope effect when the charge-compensating anions, which are also located within the non-conducting layer in the superconducting cation-radical salts, are isotopically labeled. The existence of an isotope effect when the anions are labeled would be indicative of electron-pairing with the mediation of vibrational frequencies associated with the anions. In this paper, the authors present the results of the first isotope effect study in which isotopic labeling in the anion portion of {kappa}-(ET){sub 2}Cu(NCS){sub 2} is carried out. The authors find no isotope effect when the carbon and nitrogen atoms of the thiocyanate groups in the anion are replaced with {sup 13}C and {sup 15}N isotopes.

Kini, A.M.; Wang, H.H.; Schlueter, J.A. [and others

1995-12-31T23:59:59.000Z

168

Isotopic Analysis- Fluid At Valles Caldera - Redondo Area (White, Et Al.,  

Open Energy Info (EERE)

Isotopic Analysis- Fluid At Valles Caldera - Redondo Area (White, Et Al., Isotopic Analysis- Fluid At Valles Caldera - Redondo Area (White, Et Al., 1992) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Valles Caldera - Redondo Area (White, Et Al., 1992) Exploration Activity Details Location Valles Caldera - Redondo Area Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness not indicated DOE-funding Unknown Notes Used various geochemical techniques to obtain data from which information regarding mass transfer rates. This then led to conclucions of the history/evolution of the geothermal system. Unclear whether useful for exploration purposes. References Art F. White, Nancy J. Chuma, Fraser Goff (1992) Mass Transfer Constraints On The Chemical Evolution Of An Active Hydrothermal System,

169

Isotopic Analysis At U.S. West Region (Welhan, Et Al., 1988) | Open Energy  

Open Energy Info (EERE)

U.S. West Region (Welhan, Et Al., 1988) U.S. West Region (Welhan, Et Al., 1988) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At U.S. West Region (Welhan, Et Al., 1988) Exploration Activity Details Location U.S. West Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful DOE-funding Unknown Notes Helium isotope ratios are not correlated with regional heat flow in the western United States. High helium isotope ratios (R/RA > 2) occur only in magma-based geothermal systems. A direct correlation exists between geothermal reservoir temperature and helium isotope ratio of the fluids, suggesting that both heat and helium in a geothermal reservoir are derived from a shallow magmatic source. The rapid lateral decrease in 3He away from

170

Investigation of Microphysical Processes Occurring in Isolated Convection during NAME  

Science Conference Proceedings (OSTI)

To address questions regarding microphysical processes occurring in the core North American monsoon region, data from NCAR’s S-band polarimetric Doppler radar (S-Pol) deployed during the North American Monsoon Experiment (NAME) in the summer of ...

Angela K. Rowe; Steven A. Rutledge; Timothy J. Lang

2011-02-01T23:59:59.000Z

171

Compelling Research Opportunities using Isotopes  

SciTech Connect

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.

None

2009-04-23T23:59:59.000Z

172

Reconstruction of Early Paleogene North Pacific Deep-Water Circulation using the Neodymium Isotopic Composition of Fossil Fish Debris  

E-Print Network (OSTI)

To better understand the operating mode of the deep oceans during fundamentally warm climate intervals, we present new Nd isotope data from Deep Sea Drilling Project and Ocean Drilling Program sites in the North Pacific to expand the reconstruction of water mass composition and structure during the early Cenozoic. Fossil fish debris from Sites 192, 464, 465, 883, 884 and 1208 (paleowater depths spanning 900 to 4000 m) were used to reconstruct the water mass composition from ~85 to 30 Ma. The fish debris is shown to not be overprinted as there was no systematic offset between the detrital silicate and the fish debris composition. Cleaned and uncleaned fish debris were both included in the reconstruction of water mass composition as they were found to record the same Nd isotope composition. North Pacific deep water convection occurred from ~67 to 45 Ma, the peak in production is recorded by broadly coincident trends at Sites 192, 464 and 883. Further support for North Pacific deep-water convection during the early Paleogene are the geographic trends in detrital silicate versus fish debris composition, greater separation at the more northerly Emperor Seamount sites, and the location of the most radiogenic detrital values at the Emperor Seamount sites. The Emperor Seamount chain likely played a major role in the flow of the North Pacific deep-water mass as it acted as a physical barrier to flow at deep-water sites compared to shallow depths (albeit still deep-water). ?Nd values indicate the timing of the cessation of major, deep convection in the North Pacific occurred much earlier, ~52 Ma than the timing obtained from shallower Shatsky Rise sites, ~45 Ma. Convection in the North Pacific likely produced a dense water mass that influenced the deeper sites in this study more than the shallower sites until ~52 Ma when convection was not as intense or the waters were not sufficiently dense to impact the deeper sites. Deep water convection was most intense during the relatively “cool” portion of the Late Cretaceous and Early Paleocene.

Hague, Ashley Melissa

2011-08-01T23:59:59.000Z

173

Isotopic Analysis- Rock | Open Energy Information  

Open Energy Info (EERE)

Isotopic Analysis- Rock Isotopic Analysis- Rock Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Isotopic Analysis- Rock Details Activities (13) Areas (11) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Water rock interaction Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Isotopic Analysis- Rock: Isotopes are atoms of the same element that have different numbers of neutrons. An isotopic analysis looks at a particular isotopic element(s) in a given system, while the conditions which increase/decrease the number of neutrons are well understood and measurable.

174

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)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous, toxic contaminants that are released to the environment from various petrogenic and pyrogenic sources. In an effort to more clearly identify and trace sources of PAHs in the environment, 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 highly pure extracts using various chromatographic techniques. The method was refined by improving compound separations using purification techniques and high resolution chromatographic columns. The purification method consists of alumina/silica gel column chromatography, gel permeation chromatography and thin layer chromatography. The mean recovery of PAHs after the purification procedure was approximately 80 %. Sample purities after purification were verified by GC/FID and full scan mass spectrometry. To better resolve peaks and provide more accurate stable carbon isotope measurements, various gas chromatographic conditions were evaluated. The precision of the method ranged between 0.08 and 0.43 . The analytical protocols were evaluated to confirm compositional and stable isotopic integrity during purification and stable isotopic analysis. To confirm the utility of the purification and isotope analysis methods, various environmental samples from marine, land and lacustrine environments were analyzed. The isolates were analyzed for the composition and the stable carbon isotope ratios of PAHs. The stable carbon isotope ratio was measured by GC/IRMS and the results, along with quantitative compound compositions, were used to characterize and identify the contaminant sources. The sources of the PAHs in the study areas were differentiated by PAH molecular ratios and confirmed by stable carbon isotope ratios. This study confirms that compound specific isotope analysis of pollutants by GC/IRMS can be used to identify PAH sources in environmental samples. The study also confirms that the purification and stable carbon isotope analysis methods that were developed can be used to accurately measure the stable carbon isotope ratios of PAHs in environmental samples for the purpose of source identification. GC/IRMS measurement of stable isotopic compositions can be an effective fingerprinting method when used in conjunction with traditional molecular composition methods.

Kim, Moon Koo

2004-08-01T23:59:59.000Z

175

Multidetector calibration for mass spectrometers  

SciTech Connect

The International Atomic Energy Agency`s Safeguards Analytical Laboratory has performed calibration experiments to measure the different efficiencies among multi-Faraday detectors for a Finnigan-MAT 261 mass spectrometer. Two types of calibration experiments were performed: (1) peak-shift experiments and (2) peak-jump experiments. For peak-shift experiments, the ion intensities were measured for all isotopes of an element in different Faraday detectors. Repeated measurements were made by shifting the isotopes to various Faraday detectors. Two different peak-shifting schemes were used to measure plutonium (UK Pu5/92138) samples. For peak-jump experiments, ion intensities were measured in a reference Faraday detector for a single isotope and compared with those measured in the other Faraday detectors. Repeated measurements were made by switching back-and-forth between the reference Faraday detector and a selected Faraday detector. This switching procedure is repeated for all Faraday detectors. Peak-jump experiments were performed with replicate measurements of {sup 239}Pu, {sup 187}Re, and {sup 238}U. Detector efficiency factors were estimated for both peak-jump and peak-shift experiments using a flexible calibration model to statistically analyze both types of multidetector calibration experiments. Calculated detector efficiency factors were shown to depend on both the material analyzed and the experimental conditions. A single detector efficiency factor is not recommended for each detector that would be used to correct routine sample analyses. An alternative three-run peak-shift sample analysis should be considered. A statistical analysis of the data from this peak-shift experiment can adjust the isotopic ratio estimates for detector differences due to each sample analysis.

Bayne, C.K. [Oak Ridge National Lab., TN (United States); Donohue, D.L.; Fiedler, R. [IAEA, Seibersdorf (Austria). Safeguards Analytical Lab.

1994-06-01T23:59:59.000Z

176

Novel hybrid isotope separation scheme and apparatus  

DOE Patents (OSTI)

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.

Maya, Jakob (Brookline, MA)

1991-01-01T23:59:59.000Z

177

Studies in Photosynthesis with Isotopes  

E-Print Network (OSTI)

chlorophyll) SCHEMATIC DIAGRAM OF PHOTOSYNTHESIS Fig, P Fig.2 Time of photosynthesis 60c.f M U 1646 Fig. 5 Fig. 8 Fig. 94705-eng-48 STUDIES IN PHOTOSYNTHESIS WITH ISOTOPES M Calvin

Calvin, M.; Bassham, J.A.

1952-01-01T23:59:59.000Z

178

Isotope separation apparatus and method  

DOE Patents (OSTI)

The invention relates to an improved method and apparatus for laser isotope separation by photodeflection. A molecular beam comprising at least two isotopes to be separated intersects, preferably substantially perpendicular to one broad side of the molecular beam, with a laser beam traveling in a first direction. The laser beam is reflected back through the molecular beam, preferably in a second direction essentially opposite to the first direction. Because the molecules in the beam occupy various degenerate energy levels, if the laser beam comprises chirped pulses comprising selected wavelengths, the laser beam will very efficiently excite substantially all unexcited molecules and will cause stimulated emission of substantially all excited molecules of a selected one of the isotopes in the beam which such pulses encounter. Excitation caused by first direction chirped pulses moves molecules of the isotope excited thereby in the first direction. Stimulated emission of excited molecules of the isotope is brought about by returning chirped pulses traveling in the second direction. Stimulated emission moves emitting molecules in a direction opposite to the photon emitted. Because emitted photons travel in the second direction, emitting molecules move in the first direction. Substantial molecular movement of essentially all the molecules containing the one isotope is accomplished by a large number of chirped pulse-molecule interactions. A beam corer collects the molecules in the resulting enriched divergent portions of the beam.

Feldman, Barry J. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

179

Mass Finishing  

Science Conference Proceedings (OSTI)

Table 8 Operating conditions for mass finishing...Brass screw-machine parts Aluminum oxide or granite 6.4-19 0.25-0.75 [MathExpression] -6 Light matte or bright Light cutting (a) Brass stampings or screws (b) Limestone 3.2-13 0.13-0.50 2-6 Bright (a) Submerged tumbling is used for fragile and precision parts. (b) Screw-machine parts...

180

Isotope production facility produces cancer-fighting actinium  

NLE Websites -- All DOE Office Websites (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...

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Carbon Isotope Separation and Molecular Formation in Laser-Induced...  

NLE Websites -- All DOE Office Websites (Extended Search)

Carbon Isotope Separation and Molecular Formation in Laser-Induced Plasmas by Laser Ablation Molecular Isotopic Spectrometry Title Carbon Isotope Separation and Molecular Formation...

182

On properties of certain classical operators occurring in Fourier analysis  

Science Conference Proceedings (OSTI)

Properties of conjugate functions, Hilbert transforms, and certain maximal operators occurring in Fourier analysis in weighted Lebesgue spaces are established. For functions of several variables in Orlicz spaces the divergence in measure of the Cesaro and the Abel means of the conjugate trigonometric series, and the question of the existence of conjugate functions are investigated.

Zhizhiashvili, L V; Tkebuchava, G E [I. Javakhishvili Tbilisi State University, Tbilisi (Georgia)

2004-10-31T23:59:59.000Z

183

Isotopic Effect on Ion Mobility and Separation of Isotopomers by High-Field Ion Mobility Spectrometry  

SciTech Connect

Since early 1900-s, when vacuum techniques and ion detectors first enabled investigations of gas-phase ions, two approaches to their separation and characterization have emerged - mass spectrometry (MS) and ion mobility spectrometry (IMS).1,2 Though both exploit that distinct charged species move in electric fields differently, MS is performed in vacuum and is based only on the ion mass/charge (m/q) ratio while IMS involves sufficiently dense buffer gases and relies on ion transport properties. The first major discovery enabled by MS was the existence of isotopes by Thomson and Aston,3 and isotopic analyses have since been integral to MS. In particular, the preparative separation of U isotopes using Lawrence’s Calutron was the first industrial application of MS,4 and isotopic labeling is key to MS quantification methods. With IMS, the issue of isotopes was largely ignored as the resolving power (R) was generally too low for their separation. Here, we demonstrate that recently developed high-resolution differential IMS can separate isotopic molecular ions, including nominal isobars with different isotopic content and isotopomers. This capability may enable a new method for isotope separation in a small-scale format at ambient pressure and aid localization of labeled sites in various molecules. Perhaps most importantly, the isotopic shifts depend on the labeled atom position and thus may contain the kind of detailed structural information that is available in solution or solid state using tools such as NMR but has not generally been obtainable for gas-phase ions.

Shvartsburg, Alexandre A.; Clemmer, David E.; Smith, Richard D.

2010-10-01T23:59:59.000Z

184

Heat and mass exchanger  

Science Conference Proceedings (OSTI)

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.

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

2011-06-28T23:59:59.000Z

185

Definition: Isotopic Analysis- Fluid | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Isotopic Analysis- Fluid Jump to: navigation, search Dictionary.png Isotopic Analysis- Fluid Isotopes are atoms of the same element that have different numbers of neutrons. An isotopic analysis looks at a particular isotopic element(s) in a given system, while the conditions which increase/decrease the number of neutrons are well understood and measurable. Fluid isotopes are used to characterize a fluids origin, age, and/or interaction with rocks or other fluids based on unique isotopic ratios or concentrations.[1] View on Wikipedia Wikipedia Definition Isotope geochemistry is an aspect of geology based upon study of the relative and absolute concentrations of the elements and their isotopes in

186

Time of flight mass spectrometer  

DOE Patents (OSTI)

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.

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

1984-01-01T23:59:59.000Z

187

Isotope separation apparatus and method  

DOE Patents (OSTI)

The invention relates to a method and apparatus for laser isotope separation by photodeflection. A molecular beam comprising at least two isotopes to be separated intersects, preferable substantially perpendicular to one broad side of the molecular beam, with a laser beam traveling in a first direction. The laser beam is reflected back through the molecular beam, preferably in a second direction essentially opposite to the first direction. The laser beam comprises .pi.-pulses of a selected wavelength which excite unexcited molecules, or cause stimulated emission of excited molecules of one of the isotopes. Excitation caused by first direction .pi.-pulses moves molecules of the isotope excited thereby in the first direction. Stimulated emission of excited molecules of the isotope is brought about by returning .pi.-pulses traveling in the second direction. Stimulated emission moves emitting molecules in a direction opposite to the photon emitted. Because emitted photons travel in the second direction, emitting molecules move in the first direction. Substantial molecular movement is accomplished by a large number of .pi.-pulse-molecule interactions. A beam corer collects the molecules in the resulting enriched divergent portions of the beam.

Cotter, Theodore P. (Los Alamos, NM)

1982-12-28T23:59:59.000Z

188

Neutrinoless double beta decay and neutrino masses  

SciTech Connect

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.

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

2012-07-27T23:59:59.000Z

189

PLANETARY-SCALE STRONTIUM ISOTOPIC HETEROGENEITY AND THE AGE OF VOLATILE DEPLETION OF EARLY SOLAR SYSTEM MATERIALS  

SciTech Connect

Isotopic anomalies in planetary materials reflect both early solar nebular heterogeneity inherited from presolar stellar sources and processes that generated non-mass-dependent isotopic fractionations. The characterization of isotopic variations in heavy elements among early solar system materials yields important insight into the stellar environment and formation of the solar system, and about initial isotopic ratios relevant to long-term chronological applications. One such heavy element, strontium, is a central element in the geosciences due to wide application of the long-lived {sup 87}Rb-{sup 87}Sr radioactive as a chronometer. We show that the stable isotopes of Sr were heterogeneously distributed at both the mineral scale and the planetary scale in the early solar system, and also that the Sr isotopic heterogeneities correlate with mass-independent oxygen isotope variations, with only CI chondrites plotting outside of this correlation. The correlation implies that most solar system material formed by mixing of at least two isotopically distinct components: a CV-chondrite-like component and an O-chondrite-like component, and possibly a distinct CI-chondrite-like component. The heterogeneous distribution of Sr isotopes may indicate that variations in initial {sup 87}Sr/{sup 86}Sr of early solar system materials reflect isotopic heterogeneity instead of having chronological significance, as interpreted previously. For example, given the differences in {sup 84}Sr/{sup 86}Sr between calcium aluminum inclusions and eucrites ({epsilon}{sup 84}Sr > 2), the difference in age between these materials would be {approx}6 Ma shorter than previously interpreted, placing the Sr chronology in agreement with other long- and short-lived isotope systems, such as U-Pb and Mn-Cr.

Moynier, Frederic; Podosek, Frank A. [Department of Earth and Planetary Science and McDonnell Center for Space Sciences, Washington University, St. Louis, MO 63130 (United States); Day, James M. D. [Geosciences Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0244 (United States); Okui, Wataru; Yokoyama, Tetsuya [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8551 (Japan); Bouvier, Audrey [Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455-0231 (United States); Walker, Richard J., E-mail: moynier@levee.wustl.edu, E-mail: fap@levee.wustl.edu, E-mail: jmdday@ucsd.edu, E-mail: rjwalker@umd.edu, E-mail: okui.w.aa@m.titech.ac.jp, E-mail: tetsuya.yoko@geo.titech.ac.jp, E-mail: abouvier@umn.edu [Department of Geology, University of Maryland, College Park, MD 20742 (United States)

2012-10-10T23:59:59.000Z

190

Evolution and Dynamics of a Late-Stage Squall Line That Occurred on 20 February 1993 during TOGA COARE  

Science Conference Proceedings (OSTI)

Airborne Doppler and flight-level data are used to document the structure and evolution of portions of a late-stage horseshoe-shaped squall line system and its effect on vertical momentum and mass transports. This system, which occurred on 20 ...

Sharon A. Lewis; Margaret A. LeMone; David P. Jorgensen

1998-12-01T23:59:59.000Z

191

It's Elemental - Isotopes of the Element Mendelevium  

NLE Websites -- All DOE Office Websites (Extended Search)

The Periodic Table of Elements Next Element (Nobelium) Nobelium Isotopes of the Element Mendelevium Click for Main Data Most of the isotope data on this site has been obtained...

192

It's Elemental - Isotopes of the Element Uranium  

NLE Websites -- All DOE Office Websites (Extended Search)

Periodic Table of Elements Next Element (Neptunium) Neptunium Isotopes of the Element Uranium Click for Main Data Most of the isotope data on this site has been obtained from...

193

It's Elemental - Isotopes of the Element Lithium  

NLE Websites -- All DOE Office Websites (Extended Search)

Periodic Table of Elements Next Element (Beryllium) Beryllium Isotopes of the Element Lithium Click for Main Data Most of the isotope data on this site has been obtained from...

194

It's Elemental - Isotopes of the Element Hydrogen  

NLE Websites -- All DOE Office Websites (Extended Search)

The Periodic Table of Elements Next Element (Helium) Helium Isotopes of the Element Hydrogen Click for Main Data Most of the isotope data on this site has been obtained from...

195

Unified Model for the Heat Transfer Processes that Occur During  

E-Print Network (OSTI)

A unified general model for the heat transfer processes that occur within a food product subjected to canning or aseptic thermal treatment, is presented. Two principles are extensively used in the model building process: system segregation and energy balancing. The model is summarized in an algorithm, whose specification is showed for different combinations of processing system type (PST) and product formulation (PF) with a single particle type. A discussion on the practical relevance of proper product identification in the case of aseptic processing, is included. Finally, an illustration is given on the results that can be obtained from the model algorithm application, in a comparative study of different PST-PF combinations.

Jose F. Pastrana; Harvey J. Gold; Kenneth R. Swanzel; Pastrana Gold; Jose F. Pastrana; Harvey J. Gold; Kenneth R. Swartzel

1992-01-01T23:59:59.000Z

196

Naturally occurring crystalline phases: analogues for radioactive waste forms  

SciTech Connect

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.

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

1981-01-01T23:59:59.000Z

197

AVLIS enrichment of medical isotopes  

SciTech Connect

Under the Sponsorship of the United states Enrichment Corporation (USEC), we are currently investigating the large scale separation of several isotopes of medical interest using atomic vapor isotope separation (AVLIS). This work includes analysis and experiments in the enrichment of thallium 203 as a precursor to the production of thallium 201 used in cardiac imaging following heart attacks, on the stripping of strontium 84 from natural strontium as precursor to the production of strontium 89, and on the stripping of lead 210 from lead used in integrated circuits to reduce the number of alpha particle induced logic errors.

Haynam, C.A.; Scheibner, K.F.; Stern, R.C.; Worden, E.F. [Lawrence Livermore National Laboratory, CA (United States)

1996-12-31T23:59:59.000Z

198

ISOTOPE FRACTIONATION Isotopes are atoms whose nuclei contain the same number of protons but a different number of neutrons. The  

E-Print Network (OSTI)

for the utilization of stable isotopes in geology, geochemistry, biogeochemistry, paleoceanography and elsewhere____________________________ ISOTOPE FRACTIONATION ____________________________ Isotopes are atoms whose nuclei contain the same number of protons but a different number of neutrons. The term `isotope

Zeebe, Richard E.

199

Isotope GeoloGy1 Unlike physics or chemistry, teaching isotope  

E-Print Network (OSTI)

Isotope GeoloGy1 Unlike physics or chemistry, teaching isotope geochemistry is difficult because. Writing an effective book on geochemistry is thus even more difficult. Claude Allègre's Isotope Geology geochemistry book, given how effective the texts by Faure and Dickin are. However, Allègre's Isotope Geology

Lee, Cin-Ty Aeolus

200

Isotope Development & Production | Nuclear Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

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

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Isotopic Abundance in Atom Trap Trace Analysis  

isotopes for climate change and nuclear proliferation interests. The Invention Argonne scientists have created a novel method and system for

202

Level densities of nickel isotopes: microscopic theory versus experiment  

E-Print Network (OSTI)

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.

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

2013-05-01T23:59:59.000Z

203

"Environmental Isotope Geochemistry": Past, Present Mark Baskaran  

E-Print Network (OSTI)

Chapter 1 "Environmental Isotope Geochemistry": Past, Present and Future Mark Baskaran 1.1 Introduction and Early History A large number of radioactive and stable isotopes of the first 95 elements unraveling many secrets of our Earth and its environmental health. These isotopes, because of their suitable

Baskaran, Mark

204

Kinetic Isotope Effects for the Reactions of Muonic Helium and Muonium with H2  

DOE Green Energy (OSTI)

The neutral muonic helium atom may be regarded as the heaviest isotope of the hydrogen atom, with a mass of ~4.1 amu (4.1H), because the negative muon screens one proton charge. We report the reaction rate of 4.1H with 1H2 to produce 4.1H1H + 1H at 295 to 500 K. The experimental rate constants are compared with the predictions of accurate quantum mechanical dynamics calculations carried out on an accurate Born-Huang potential energy surface and with previously measured rate constants of 0.11H (where 0.11H is shorthand for muonium). Kinetic isotope effects can be compared for the unprecedentedly large mass ratio of 36. The agreement with accurate quantum dynamics is quantitative at 500 K, and variational transition state theory is used to interpret the extremely low (large inverse) kinetic isotope effects in the 10-4 to 10-2 range.

Fleming, Donald G.; Arseneau, Donald J.; Sukhorukov, Oleksandr; Brewer, Jess H.; Mielke, Steven L.; Schatz, George C.; Garrett, Bruce C.; Peterson, Kirk A.; Truhlar, Donald G.

2011-01-28T23:59:59.000Z

205

Radioactive isotopes on the Moon  

SciTech Connect

A limited review of experiments and studies of radioactivity and isotope ratios in lunar materials is given. Observations made on the first few millimeters of the surface where the effects of solar flare particles are important, some measurements on individual rocks, and some studies of radioactivities produced deep in the lunar soil by galactic cosmic rays, are among the experiments discussed. (GHT)

Davis, R. Jr.

1975-01-01T23:59:59.000Z

206

Is anyone regulating naturally occurring radioactive material? A state survey  

SciTech Connect

As far as we know, naturally occurring radioactive material (NORM) has surrounded humankind since the beginning of time. However, recent data demonstrating that certain activities concentrate NORM have increased concern regarding its proper handling and disposal and precipitated the development of new NORM-related regulations. The regulation of NORM affects the management of government facilities as well as a broad range of industrial processes. Recognizing that NORM regulation at the federal level is extremely limited, Argonne National Laboratory (ANL) conducted a 50-state survey to determine the extent to which states have assumed the responsibility for regulating NORM as well as the NORM standards that are currently being applied at the state level. Though the survey indicates that NORM regulation comprises a broad spectrum of controls from full licensing requirements to virtually no regulation at afl, a trend is emerging toward recognition of the need for increased regulation of potential NORM hazards, particularly in the absence of federal standards.

Gross, E.M.; Barisas, S.G.

1993-08-01T23:59:59.000Z

207

Electroplating method for producing ultralow-mass fissionable deposits  

DOE Patents (OSTI)

A method for producing ultralow-mass fissionable deposits for nuclear reactor dosimetry is described, including the steps of holding a radioactive parent until the radioactive parent reaches secular equilibrium with a daughter isotope, chemically separating the daughter from the parent, electroplating the daughter on a suitable substrate, and holding the electroplated daughter until the daughter decays to the fissionable deposit.

Ruddy, Francis H. (Monroeville, PA)

1989-01-01T23:59:59.000Z

208

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

DOE Green Energy (OSTI)

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.

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

2010-01-01T23:59:59.000Z

209

Cu isotope fractionation during bornite dissolution: An in situ X-ray diffraction analysis  

Science Conference Proceedings (OSTI)

Low-temperature ore deposits exhibit a large variation in {delta}{sup 65}Cu ({approx}12{per_thousand}), and this range has been attributed, in part, to isotope fractionation during weathering reactions of primary minerals such as chalcocite and chalcopyrite. Here, we examine the fractionation of Cu isotopes during dissolution of another important Cu ore mineral, bornite, using a novel approach that combines time-resolved X-ray diffraction (XRD) and isotope analysis of reaction products. During the initial stages of bornite oxidative dissolution by ferric sulfate ( 20 mol% Cu was leached from the solid, the difference between the Cu isotope composition of the aqueous and mineral phases approached zero, with {Delta}{sub aq - min}{sup 0} values ranging from - 0.21 {+-} 0.61{per_thousand} to 0.92 {+-} 0.25{per_thousand}. XRD analysis allowed us to correlate changes in the atomic structure of bornite with the apparent isotope fractionation as the dissolution reaction progressed. These data revealed that the greatest degree of apparent fractionation is accompanied by a steep contraction in the unit-cell volume, which we identified as a transition from stoichiometric to non-stoichiometric bornite. We propose that the initially high {Delta}{sub aq - min} values result from isotopically heavy Cu ({sup 65}Cu) concentrating within Cu{sup 2+} during dissolution. The decrease in the apparent isotope fractionation as the reaction progresses occurs from the distillation of isotopically heavy Cu ({sup 65}Cu) during dissolution or kinetic isotope effects associated with the depletion of Cu from the surfaces of bornite particles.

Wall, Andrew J.; Mathur, Ryan; Post, Jeffrey E.; Heaney, Peter J. (Juniata); (Smithsonian); (Penn)

2012-10-24T23:59:59.000Z

210

Definition: Isotopic Analysis- Rock | Open Energy Information  

Open Energy Info (EERE)

Isotopic Analysis- Rock Isotopic Analysis- Rock Jump to: navigation, search Dictionary.png Isotopic Analysis- Rock Isotopes are atoms of the same element that have different numbers of neutrons. An isotopic analysis looks at a particular isotopic element(s) in a given system, while the conditions which increase/decrease the number of neutrons are well understood and measurable.[1] View on Wikipedia Wikipedia Definition References ↑ http://wwwrcamnl.wr.usgs.gov/isoig/isopubs/itchch2.html Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like. rieved from "http://en.openei.org/w/index.php?title=Definition:Isotopic_Analysis-_Rock&oldid=687702" Category: Definitions What links here Related changes Special pages Printable version Permanent link Browse properties

211

Scrap metal management issues associated with naturally occurring radioactive material  

Science Conference Proceedings (OSTI)

Certain industrial processes sometimes generate waste by-products that contain naturally occurring radioactive material (NORM) at elevated concentrations. Some industries, including the water treatment, geothermal energy, and petroleum industries, generate scrap metal that may be contaminated with NORM wastes. Of these three industries, the petroleum industry probably generates the largest quantity of NORM-contaminated equipment, conservatively estimated at 170,000 tons per year. Equipment may become contaminated when NORM-containing scale or sludge accumulates inside water-handling equipment. The primary radionuclides of concern in these NORM wastes are radium-226 and radium-228. NORM-contaminated equipment generated by the petroleum industry currently is managed several ways. Some equipment is routinely decontaminated for reuse; other equipment becomes scrap metal and may be disposed of by burial at a licensed landfill, encapsulation inside the wellbore of an abandoned well, or shipment overseas for smelting. In view of the increased regulatory activities addressing NORM, the economic burden of managing NORM-contaminated wastes, including radioactive scrap metal, is likely to continue to grow. Efforts to develop a cost-effective strategy for managing radioactive scrap metal should focus on identifying the least expensive disposition options that provide adequate protection of human health and the environment. Specifically, efforts should focus on better characterizing the quantity of radioactive scrap available for recycle or reuse, the radioactivity concentration levels, and the potential risks associated with different disposal options.

Smith, K.P.; Blunt, D.L.

1995-08-01T23:59:59.000Z

212

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

E-Print Network (OSTI)

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.

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

2013-02-08T23:59:59.000Z

213

Using Stable Water Isotopes to Evaluate Basin-Scale Simulations of Surface Water Budgets  

Science Conference Proceedings (OSTI)

Two rare but naturally occurring isotopes of water, 1H218O and 1H2H16O, are becoming of practical use in diagnosis of climate and earth system model performance. Their value as tracers and validation tools in hydrological subsystems derives from ...

A. Henderson-Sellers; K. McGuffie; D. Noone; P. Irannejad

2004-10-01T23:59:59.000Z

214

Reconciling Change in Oi-Horizon Carbon-14 with Mass Loss for an Oak Forest  

SciTech Connect

First-year litter decomposition was estimated for an upland-oak forest ecosystem using enrichment or dilution of the 14C-signature of the Oi-horizon. These isotopically-based mass-loss estimates were contrasted with measured mass-loss rates from past litterbag studies. Mass-loss derived from changes in the 14C-signature of the Oi-horizon suggested mean mass loss over 9 months of 45% which was higher than the corresponding 9-month rate extrapolated from litterbag studies (~35%). Greater mass loss was expected from the isotopic approach because litterbags are known to limit mass loss processes driven by soil macrofauna (e.g., fragmentation and comminution). Although the 14C-isotope approach offers the advantage of being a non-invasive method, it exhibited high variability that undermined its utility as an alternative to routine litterbag mass loss methods. However, the 14C approach measures the residence time of C in the leaf litter, rather than the time it takes for leaves to disappear; hence radiocarbon measures reflect C immobilization and recycling in the microbial pool, and do not necessarily replicate results from litterbag mass loss. The commonly applied two-compartment isotopic mixing model was appropriate for estimating decomposition from isotopic enrichment of near-background soils, but it produced divergent results for isotopic dilution of a multi-layered system with litter cohorts having independent 14C-signatures. This discrepancy suggests that cohort-based models are needed to adequately capture the complex processes involved in carbon transport associated with litter mass-loss. Such models will be crucial for predicting intra- and interannual differences in organic horizon decomposition driven by scenarios of climatic change.

Hanson, Paul J [ORNL; Swanston, Christopher W. [Lawrence Livermore National Laboratory (LLNL); Garten Jr, Charles T [ORNL; Todd Jr, Donald E [ORNL; Trumbore, Susan E. [University of California, Irvine

2005-01-01T23:59:59.000Z

215

Reconciling Change in Oi-Horizon 14C With Mass Loss for an Oak Forest  

SciTech Connect

First-year litter decomposition was estimated for an upland-oak forest ecosystem using enrichment or dilution of the {sup 14}C-signature of the Oi-horizon. These isotopically-based mass-loss estimates were contrasted with measured mass-loss rates from past litterbag studies. Mass-loss derived from changes in the {sup 14}C-signature of the Oi-horizon suggested mean mass loss over 9 months of 45% which was higher than the corresponding 9-month rate extrapolated from litterbag studies ({approx}35%). Greater mass loss was expected from the isotopic approach because litterbags are known to limit mass loss processes driven by soil macrofauna (e.g., fragmentation and comminution). Although the {sup 14}C-isotope approach offers the advantage of being a non-invasive method, it exhibited high variability that undermined its utility as an alternative to routine litterbag mass loss methods. However, the {sup 14}C approach measures the residence time of C in the leaf litter, rather than the time it takes for leaves to disappear; hence radiocarbon measures are subject to C immobilization and recycling in the microbial pool, and do not necessarily reflect results from litterbag mass loss. The commonly applied two-compartment isotopic mixing model was appropriate for estimating decomposition from isotopic enrichment of near-background soils, but it produced divergent results for isotopic dilution of a multi-layered system with litter cohorts having independent {sup 14}C-signatures. This discrepancy suggests that cohort-based models are needed to adequately capture the complex processes involved in carbon transport associated with litter mass-loss. Such models will be crucial for predicting intra- and interannual differences in organic horizon decomposition driven by scenarios of climatic change.

Hanson, P J; Swanston, C W; Garten, Jr., C T; Todd, D E; Trumbore, S E

2005-06-27T23:59:59.000Z

216

High-Performance Mass Spectrometry Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

HPMSF Overview HPMSF Overview Section 2-4-1 High-Performance Mass Spectrometry Facility The High-Performance Mass Spectrometry Facility (HPMSF) provides state-of-the-art mass spectrometry (MS) and separations instrumentation that has been refined for leading-edge analysis of biological problems with a primary emphasis on proteomics. Challenging research in proteomics, cell signaling, cellular molecular machines, and high-molecular weight systems receive the highest priority for access to the facility. Current research activities in the HPMSF include proteomic analyses of whole cell lysates, analyses of organic macro-molecules and protein complexes, quantification using isotopically labeled growth media, targeted proteomics analyses of subcellular fractions, and nucleic acid analysis of

217

Models for calculating the effects of isotopic exchange, radioactive decay, and of recycle in removing iodine from gas and liquid streams  

SciTech Connect

Different decontamination factors for $sup 129$I and $sup 131$I are frequently invoked in environmental impact reports concerned with nuclear fuel recycle. Selected differences, or ratios, have not been justified on the basis of mathematical models or experimental data. A description is given of the origins of these differences in terms of isotopic exchange and material balance equations for the short- and long-lived (or stable) isotopes. The ratios of decontamination factors can be calculated when there is complete attainment of isotopic exchange between gas- or liquid-phase iodine and iodine sorbed by a solid or liquid. If there is no exchange, decontamination factors are isotope- independent unless material recycle occurs within the system. Between these extremes, there can be decontamination factors whose explanation requires experimental determination of the extent of exchange. The model applies to other radioactive isotopes of iodine as well as to other elements with short- and long- lived (or stable) isotopes. (auth)

Davis, W. Jr.

1975-09-01T23:59:59.000Z

218

Manufactured Home Testing in Simulated and Naturally Occurring High Winds  

SciTech Connect

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.

W. D. Richins; T. K. Larson

2006-08-01T23:59:59.000Z

219

The on-line charge breeding program at TRIUMF's Ion Trap For Atomic and Nuclear Science for precision mass measurements  

Science Conference Proceedings (OSTI)

TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing the charge state of short-lived nuclides prior to the actual mass determination in a Penning trap. Recent developments around TITAN's charge breeder, the electron beam ion trap, form the basis for several successful experiments on radioactive isotopes with half-lives as low as 65 ms and in charge states as high as 22+.

Simon, M. C.; Eberhardt, B.; Jang, F.; Luichtl, M.; Robertson, D.; Chaudhuri, A.; Delheij, P.; Grossheim, A.; Kwiatkowski, A. A.; Mane, E.; Pearson, M. R.; Schultz, B. E. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Bale, J. C. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Chowdhury, U. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Ettenauer, S.; Gallant, A. T.; Dilling, J. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1 (Canada); Lennarz, A. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet, D-48149 Muenster (Germany); Ma, T.; Andreoiu, C. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); and others

2012-02-15T23:59:59.000Z

220

Geological isotope anomalies as signatures of nearby supernovae  

E-Print Network (OSTI)

Nearby supernova explosions may cause geological isotope anomalies via the direct deposition of debris or by cosmic-ray spallation in the earth's atmosphere. We estimate the mass of material deposited terrestrially by these two mechanisms, showing the dependence on the supernova distance. A number of radioactive isotopes are identified as possible diagnostic tools, such as Be-10, Al-26, Cl-36, Mn-53, Fe-60, and Ni-59, as well as the longer-lived I-129, Sm-146, and Pu-244. We discuss whether the 35 and 60 kyr-old Be-10 anomalies observed in the Vostok antarctic ice cores could be due to supernova explosions. Combining our estimates for matter deposition with results of recent nucleosynthesis yields, we calculate the expected signal from nearby supernovae using ice cores back to \\sim 300 kyr ago, and we discuss using deep ocean sediments back to several hundred Myr. In particular, we examine the prospects for identifying isotope anomalies due to the Geminga supernova explosion, and signatures of the possibility...

Ellis, Jonathan Richard; Schramm, David N; Ellis, John; Fields, Brian D; Schramm, David N

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Nuclear Energy Protocol for Research Isotopes Owen Lowe  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Protocol for Protocol for Research Isotopes Owen Lowe Office of Isotopes for Medicine and Science Office of Nuclear Energy, Science and Technology April 16, 2002 Isotopes for Life Isotopes for Life Isotopes for Life Office of Nuclear Energy, Science and Technology Lowe/April16_02 NEPRI to NERAC.ppt (2) Nuclear Energy Protocol For Research Isotopes Nuclear Energy Protocol For Research Isotopes Why NEPRI? 6 NEPRI implements DOE funding priorities for fiscal year 2003 6 NEPRI will * Bring order to DOE's responses to requests for research isotopes * Introduce a high-quality peer review to the selection of research isotopes * Enable DOE to concentrate on operating its unique isotope production facilities Isotopes for Life Isotopes for Life Isotopes for Life Office of Nuclear Energy, Science and Technology

222

Carbon dioxide emissions from fossil fuel consumption and cement manufacture, 1751-1991; and an estimate of their isotopic composition and latitudinal distribution  

SciTech Connect

This work briefly discusses four of the current research emphases at Oak Ridge National Laboratory regarding the emission of carbon dioxide (CO{sub 2}) from fossil fuel consumption, natural gas flaring and cement manufacture. These emphases include: (1) updating the 1950 to present time series of CO{sub 2} emissions from fossil fuel consumption and cement manufacture, (2) extending this time series back to 1751, (3) gridding the data at 1{sup 0} by 1{sup 0} resolution, and (4) estimating the isotopic signature of these emissions. In 1991, global emissions of CO{sub 2} from fossil fuel and cement increased 1.5% over 1990 levels to 6188 {times} 10{sup 6} metric tonnes C. The Kuwaiti oil fires can account for all of the increase. Recently published energy data (Etemad et al., 1991) allow extension of the CO emissions time series back to 1751. Preliminary examination shows good agreement with two other, but shorter, energy time series. A latitudinal distribution of carbon emissions is being completed. A southward shift in the major mass of CO{sub 2} emissions is occurring from European-North American latitudes towards central-southeast Asian latitudes, reflecting the growth of population and industrialization at these lower latitudes. The carbon isotopic signature of these emissions has been re-examined. The emissions of the last two decades are approximately 1{per_thousand} lighter than previously reported (Tans, 1981). This lightening of the emissions signature is due to fossil fuel gases and liquids, including a revision of their {delta}{sup 13}C isotopic signature and an increased production rate.

Andres, R.J.; Marland, G.; Boden, T.; Bischof, S.

1994-10-01T23:59:59.000Z

223

Strategic Isotope Production | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Strategic Isotope Strategic Isotope Production SHARE Strategic Isotope Production Typical capsules used in the transport of 252Cf source material inside heavily shielded shipping casks. ORNL's unique facilities at the High Flux Isotope Reactor (HFIR), Radiochemical Engineering Development Center (REDC), Irradiated Fuels Examination Laboratory (IFEL), and Irradiated Materials Examination Testing facility (IMET) are routinely used in the production, purification, packaging, and shipping of a number of isotopes of national importance, including: 75Se, 63Ni, 238Pu, 252Cf, and others. The intense neutron flux of the HFIR (2.0 x 1015 neutrons/cm²·s) permits the rapid formation of such isotopes. These highly irradiated materials are then processed and packaged for shipping using the facilities at the REDC, IFEL, and IMET.

224

Stable Isotope Enrichment Capabilities at ORNL  

SciTech Connect

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.

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

2013-01-01T23:59:59.000Z

225

Electromagnetic Isotope Separation Lab (EMIS) | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Electromagnetic Isotope Separation Lab Electromagnetic Isotope Separation Lab May 30, 2013 ORNL established the Stable Isotope Enrichment Laboratory (SIEL) as part of a project funded by the DOE Office of Science, Nuclear Physics Program to develop a modernized electromagnetic isotope separator (EMIS), optimized for separation of a wide range of stable isotopes. The SIEL is located in the Building 6010 Shield Test Station, space formerly allocated to the Oak Ridge Electron Linear Accelerator, on the main campus of ORNL. ORNL staff have designed and built a nominal 10 mA ion current EMIS (sum of all isotopes at the collector) in the SIEL. This EMIS is currently being tested to determine basic performance metrics such as throughput and enrichment factor per pass. This EMIS unit and space will be used to

226

Ultrasensitive detection of radioactive cesium isotopes using a magneto-optical trap.  

SciTech Connect

We report the first magneto-optical trapping of mdioactive {sup 135}Cs and {sup 137}Cs and a promising means for detecting these isotopes to ullrasensilive lcvels by a system coupling the magneto-optical trap (MOT) to a mass separator. The mass separator efficiently delivers a 20 kV ion beam of either isotope into a quartzcube MOT cell having in one corner a small-diameter Zr foil, on which the ion beam is focused and into which the ions are implantetl. Inductive heating of thc foil releases {approx}45% of the implanted atoms into a MOT that uses large diameter beams and a dry-film coating to capture 3% of the released vapor. MOT fluorescence signals were found to increasc linearly with the number of foil-implanted atoms over a range of 10{sup 4} to 10{sup 7} in trapped-atom number. The measured slope of MOT signal versus number implanted was equal in the case each isotope to within 4%, signifying our ability to measure {sup 137}Cs/{sup 135}Cs ratios to within 4%. The isotopic selectivities of the mass separator and MOT combine to suppress interfering signal from {sup 133}Cs by a factor of greater than 5 x 10{sup 12} in the case of detecting {sup 135}Cs or {sup 137}Cs. Our present sample detection sensitivity is one million atoms.

Di Rosa, M. D. (Michael D.); Crane, S. G. (Scott G.); Kitten, J. J. (Jason J.); Taylor, W. A. (Wayne A.); Vieira, D. J. (David J.); Zhao, X. (Xinxin)

2002-01-01T23:59:59.000Z

227

METHOD AND APPARATUS FOR COLLECTING ISOTOPES  

DOE Patents (OSTI)

A method and apparatus for collecting isotopes having a high vapor pressure, such as isotopes of mercury, in a calutron are described. Heretofore, the collected material would vaporize and escape from the ion receiver as fast as it was received. By making the receiver of pure silver, the mercury isotopes form a nonvolatile amalgam with the silver at the water cooled temperature of the receiver, and the mercury is thus retained.

Leyshon, W.E.

1957-08-01T23:59:59.000Z

228

Isotopic Analysis (Not Available) | Open Energy Information  

Open Energy Info (EERE)

Usefulness not indicated DOE-funding Unknown Notes Meeting proceedings - large list of papers and presentations dealing mostly with various isotopic analyses and their applications...

229

It's Elemental - Isotopes of the Element Nobelium  

NLE Websites -- All DOE Office Websites (Extended Search)

Mendelevium Previous Element (Mendelevium) The Periodic Table of Elements Next Element (Lawrencium) Lawrencium Isotopes of the Element Nobelium Click for Main Data Most of the...

230

It's Elemental - Isotopes of the Element Fermium  

NLE Websites -- All DOE Office Websites (Extended Search)

Einsteinium Previous Element (Einsteinium) The Periodic Table of Elements Next Element (Mendelevium) Mendelevium Isotopes of the Element Fermium Click for Main Data Most of the...

231

Available Technologies: Real Time High Throughput Isotopic ...  

Space exploration; Any scientific research involving the tracking of isotopic labels, as in: Solar power; Scintillators (deuterated, 10 B, 6 Li, 3 He) Batteries (doping)

232

Zeolite Cryopumps for Hydrogen Isotopes Transportation  

Science Conference Proceedings (OSTI)

Tritium Processing / Proceedings of the Fifth Topical Meeting on Tritium Technology in Fission, Fusion, and Isotopic Applications Belgirate, Italy May 28-June 3, 1995

Ivan A. Alekseev; Sergey P. Karpov; Veniamin D. Trenin

233

WEB RESOURCE: Exploring the Table of Isotopes  

Science Conference Proceedings (OSTI)

Feb 16, 2007 ... This page offers an interactive table of isotopes, an animated glossary of nuclear terms and relevant support documents created by the ...

234

NIDC: Online Catalog of Isotope Products Home  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalog of Isotope Products Please select an option below. PRODUCTS VIEWING Select using PERIODIC TABLE or NUCLIDE CHART or LIST SEARCHING SEARCH for a Product REQUESTING REQUEST a...

235

HFIR | High Flux Isotope Reactor | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

HFIR Working with HFIR Neutron imaging offers new tools for exploring artifacts and ancient technology Home | User Facilities | HFIR HFIR | High Flux Isotope Reactor SHARE The High...

236

Isotopic Exchange in Air Detritiation Dryers  

Science Conference Proceedings (OSTI)

Tritium Processing / Proceedings of the Third Topical Meeting on Tritium Technology in Fission, Fusion and Isotopic Applications (Toronto, Ontario, Canada, May 1-6, 1988)

A.E. Everatt; A.H. Dombra; R.E. Johnson

237

Isotopes Tell Origin and Operation of the Sun  

E-Print Network (OSTI)

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.

O. Manuel; Sumeet A. Kamat; Michael Mozina

2005-09-28T23:59:59.000Z

238

Method and apparatus for noble gas atom detection with isotopic selectivity  

DOE Patents (OSTI)

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.

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

239

CLUMPED ISOTOPIC EQUILIBRIUM AND THE RATE OF ISOTOPE EXCHANGE BETWEEN CO2 AND WATER  

E-Print Network (OSTI)

CLUMPED ISOTOPIC EQUILIBRIUM AND THE RATE OF ISOTOPE EXCHANGE BETWEEN CO2 AND WATER HAGIT P. AFFEK Department of Geology and Geophysics, Yale University, 210 Whitney Ave., New Haven, Connecticut, 06511, USA the exchange of oxygen isotopes with water. The use of 18 O as an environmental indicator typically assumes

240

Mercury Isotope Fractionation by Environmental Transport and Transformation Processes  

E-Print Network (OSTI)

isotope fractionation in fossil hydrothermal systems. Geology,isotopes: Evaporation, chemical diffusion and Soret diffusion. Chemical Geology,isotope records of atmospheric and riverine pollution from two major European heavy metal refineries. Chemical Geology,

Koster van Groos, Paul Gijsbert

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Determination of the proton separation energy of {sup 93}Rh from mass measurements  

Science Conference Proceedings (OSTI)

The proposed {nu}p process, which occurs in the early time proton-rich neutrino winds of core-collapse supernovae, has the potential to resolve the long-standing uncertainty in the production of the light p-nuclei {sup 92}Mo and {sup 94}Mo. A recent study incorporating this {nu}p process has indicated that the proton separation energy S{sub p} of {sup 93}Rh is especially important in determining the relative production of these two isotopes. To reproduce the observed solar {sup 92}Mo/{sup 94}Mo abundance ratio of 1.57 a S{sub p} value for {sup 93}Rh of 1.64{+-}0.1 MeV is required. The previously unknown masses of {sup 92}Ru and {sup 93}Rh have been measured with the Canadian Penning Trap mass spectrometer resulting in an experimental value for S{sub p}({sup 93}Rh) of 2.007{+-}0.009 MeV. This implies that with our current understanding of the conditions in core-collapse supernova explosions the {nu}p process is not solely responsible for the observed solar {sup 92}Mo/{sup 94}Mo abundance ratio.

Fallis, J.; Russell, S.; Vorst, M. Scholte van de; Sharma, H.; Wang, J. C.; Wang, Y. [Department of Physics, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Clark, J. A. [Department of Physics, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Sharma, K. S. [Department of Physics, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Savard, G.; Caldwell, S.; Sternberg, M.; Schelt, J. Van [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Buchinger, F.; Crawford, J. E.; Gulick, S.; Lee, J. K. P. [Department of Physics, McGill University, Montreal Quebec H3A 2T8 (Canada); Deibel, C. M.; Wrede, C. [Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States); Fisker, J. L. [Physical Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hecht, A. A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742 (United States)] (and others)

2008-08-15T23:59:59.000Z

242

Isotopic Analysis At Geysers Area (Lambert & Epstein, 1992) | Open Energy  

Open Energy Info (EERE)

Isotopic Analysis- Rock At Geysers Area (Lambert & Isotopic Analysis- Rock At Geysers Area (Lambert & Epstein, 1992) Exploration Activity Details Location Geysers Area Exploration Technique Isotopic Analysis- Rock Activity Date Usefulness useful DOE-funding Unknown Notes Measurements of 180/160, 13C/12C and D/H ratio variations were made by the usual methods (McCrea, 1950; Taylor and Epstein, 1962; Epstein and Taylor, 1970) using mass spectrometers of the type described by Nier (1947) with modifications by McKinney et al. (1950). Results are reported in 8-notation with respect to the SMOW (Craig, 1961 ) and PDB (Urey et al., 1951 ) standards. Analytical precisions for multiple analyses of any single sample were _+ 0.2%0 for oxygen and carbon and _ 1%o for hydrogen. Inhomogeneities of cuttings fractions gave rise to variations within single cuttings

243

Isotopic Analysis At Newberry Caldera Area (Carothers, Et Al...  

Open Energy Info (EERE)

H. Mariner, Terry E. C. Keith (1987) Isotope Geochemistry Of Minerals And Fluids From Newberry Volcano, Oregon Retrieved from "http:en.openei.orgwindex.php?titleIsotopicA...

244

EIS-0249: Medical Isotopes Production Project | Department of...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

49: Medical Isotopes Production Project EIS-0249: Medical Isotopes Production Project Summary This EIS evaluates the potential environmental impacts of a proposal to establish a...

245

Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon...  

NLE Websites -- All DOE Office Websites (Extended Search)

Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon Dioxide and Carbon-13 in Methane Modern Records of Carbon and Oxygen Isotopes in Atmospheric Carbon Dioxide and...

246

CALIFORNIUM ISOTOPES FROM BOMBARDMENT OF URANIUM WITH CARBON IONS  

E-Print Network (OSTI)

Isotopes from Bombardment of Uranium with Carbon Ions A.ISOTOPES FROM BOMBARDMENT OF URANIUM WITH CARBON IONS A.the irradiations, the uranium was dissolved in dilute

Ghiorso, A.; Thompson, S.G.; Street, K. Jr.; Seaborg, G.T.

2008-01-01T23:59:59.000Z

247

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 GEOTHERMAL ENERGYGeothermal Home Journal Article: A Helium Isotope...

248

Isotopic Analysis- Rock At Long Valley Caldera Area (Smith &...  

Open Energy Info (EERE)

Isotopic Analysis- Rock At Long Valley Caldera Area (Smith & Suemnicht, 1991) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-...

249

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

Open Energy Info (EERE)

Inyo and Kern Counties, California. Supplement. Isotope geochemistry and Appendix H. Final report Retrieved from "http:en.openei.orgwindex.php?titleIsotopicAnalysis-Flu...

250

The Quest for the Heaviest Uranium Isotope  

E-Print Network (OSTI)

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.

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

2011-07-06T23:59:59.000Z

251

5, 547577, 2008 Isotope hydrology of  

E-Print Network (OSTI)

HESSD 5, 547­577, 2008 Isotope hydrology of cave dripwaters L. Fuller et al. Title Page Abstract are under open-access review for the journal Hydrology and Earth System Sciences Isotope hydrology of Geology and Palaeontology, University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria 3 School

Paris-Sud XI, Université de

252

Dynamical aspects of isotopic scaling  

E-Print Network (OSTI)

Investigation of the effect of the dynamical stage of heavy-ion collisions indicates that the increasing width of the initial isospin distributions is reflected by a significant modification of the isoscaling slope for the final isotopic distributions after de-excitation. For narrow initial distributions, the isoscaling slope assumes the limiting value of the two individual initial nuclei while for wide initial isotopic distributions the slope for hot fragments approaches the initial value. The isoscaling slopes for final cold fragments increase due to secondary emissions. The experimentally observed evolution of the isoscaling parameter in multifragmentation of hot quasiprojectiles at E$_{inc}$=50 AMeV, fragmentation of $^{86}$Kr projectiles at E$_{inc}$=25 AMeV and multifragmentation of target spectators at relativistic energies was reproduced by a simulation with the dynamical stage described using the appropriate model (deep inelastic transfer and incomplete fusion at the Fermi energy domain and spectator-participant model at relativistic energies) and the de-excitation stage described with the statistical multifragmentation model. In all cases the isoscaling behavior was reproduced by a proper description of the dynamical stage and no unambiguous signals of the decrease of the symmetry energy coefficient were observed.

M. Veselsky

2006-07-17T23:59:59.000Z

253

ISOTOPES  

E-Print Network (OSTI)

depends on the cost and energy efficiency of the laser.and the low cost and energy efficiency of existing, large-

Lederer, C. Michael

2013-01-01T23:59:59.000Z

254

ISOTOPES  

E-Print Network (OSTI)

uranium, heavy-water-moderated CANDU reactor, as contrastedis important, and in the CANDU power reactor, which uses

Lederer, C. Michael

2013-01-01T23:59:59.000Z

255

ISOTOPES  

E-Print Network (OSTI)

U.S. Department of Energy: Uranium Enrichment (1978). UnitedRaux and W.L. Grant, uranium Enrichment in South Africa,for heavy~water and uranium enrichment is more severe. In

Lederer, C. Michael

2013-01-01T23:59:59.000Z

256

ISOTOPES  

E-Print Network (OSTI)

is somewhat uncertain~ and projections have been reducedFigure 15 shows the recent CONAES projections for the U.S. (72,90), along with earlier projections for the U.S. and the

Lederer, C. Michael

2013-01-01T23:59:59.000Z

257

ISOTOPES  

E-Print Network (OSTI)

Klein and S.V. Peterson, May 9-ll, 1973, Argonne NationalLaboratory, Argonne, Illinois (1973). 97. R.A. Muller,S.V. Peterson, May 9-11, 1973, Argonne National Laboratory,

Lederer, C. Michael

2013-01-01T23:59:59.000Z

258

ISOTOPES  

E-Print Network (OSTI)

A Guidebook to Nuclear Reactors, University of Californiaa thermal position of a nuclear reactor followed by analysisproduced by six large nuclear reactors. The power usage per

Lederer, C. Michael

2013-01-01T23:59:59.000Z

259

Selected Isotopes for Optimized Fuel Assembly Tags  

SciTech Connect

In support of our ongoing signatures project we present information on 3 isotopes selected for possible application in optimized tags that could be applied to fuel assemblies to provide an objective measure of burnup. 1. Important factors for an optimized tag are compatibility with the reactor environment (corrosion resistance), low radioactive activation, at least 2 stable isotopes, moderate neutron absorption cross-section, which gives significant changes in isotope ratios over typical fuel assembly irradiation levels, and ease of measurement in the SIMS machine 2. From the candidate isotopes presented in the 3rd FY 08 Quarterly Report, the most promising appear to be Titanium, Hafnium, and Platinum. The other candidate isotopes (Iron, Tungsten, exhibited inadequate corrosion resistance and/or had neutron capture cross-sections either too high or too low for the burnup range of interest.

Gerlach, David C.; Mitchell, Mark R.; Reid, Bruce D.; Gesh, Christopher J.; Hurley, David E.

2008-10-01T23:59:59.000Z

260

Soil-to-Crop Transfer Factors of Naturally Occurring Radionuclides and Stable Elements for Long-Term Dose Assessment  

SciTech Connect

A soil-to-crop transfer factor, TF, is a key parameter that directly affects the internal dose assessment for the ingestion pathway, however, obtaining TFs of various long-lived radionuclides occurred during operation of nuclear power plants is difficult because most of them could not be found in natural environments. In this study, therefore, we collected crops and their associated soils throughout Japan and measured more than 50 elements to obtain TFs under equilibrium conditions. The TFs were calculated for 42 elements (Li, Na, Mg, Al, Si, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Y, Mo, Cd, Sn, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tl, Pb, Th and U) from their concentrations in both crop and soil samples. The TF is defined as the concentration of an isotope in a crop (in Bq/kg or mg/kg dry weight) divided by the concentration of the isotope in soil (in Bq.kg or mg/kg dry weight). Probability distributions of TFs for 62 upland field crops were usually log-normal type so that geometric means (GMs) were calculated. The values for the elements of interest from the viewpoint of long-term dose assessment were 2.5E-02 for Se, 7.9E-02 for Sr, 3.1E-03 for Cs, 4.2E-04 for Th and 4.6E-04 for U. Leafy vegetable showed the highest TFs for all the elements among the crop groups. It was clear that these data were usually within the 95% confidence limits of TFs compiled by IAEA in Technical Report Series 364. (authors)

Uchida, S.; Tagami, K. [National Institute of Radiological Sciences, Inage-ku, Chiba (Japan)

2007-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

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

Science Conference Proceedings (OSTI)

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%.

Anheier, Norman C.; Bushaw, Bruce A.

2009-07-01T23:59:59.000Z

262

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

Science Conference Proceedings (OSTI)

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.

Maxwell, S.

2013-03-01T23:59:59.000Z

263

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

DOE Green Energy (OSTI)

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.

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

1980-05-01T23:59:59.000Z

264

A "Muon Mass Tree" with alpha-quantized Lepton, Quark and Hadron Masses  

E-Print Network (OSTI)

A "muon mass tree" is displayed that contains the excitation systematics for accurately reproducing the masses of the six Standard Model quarks (u,d,s,c,b,t); the heavy leptons; the proton; the phi, J/Psi and Upsilon vector meson thrshold states; the Bc meson; and the mass-averaged W and Z gauge bosons, using a unified mass formalism based on the electron ground state. Multiples of an alpha-quantized 105.04 MeV fermion mass quantum reproduce the states below 12 GeV, and multiples of a doubly-alpha-quantized 14,394 Mev fermion mass quantum reproduce the W-Z and t states above 12 GeV, where alpha ~ 1/137 is the fine structure constant. Masses are additive, and the overall mass accuracy for these states is in the 1% range. A similar "pion mass tree" based on an alpha-quantized 70.03 MeV boson mass quantum accurately reproduces the pseudoscalar meson masses. The mass alpha-quantization follows from a corresponding experimental alpha-spacing of the long-lived particle lifetimes, which occur in well-defined lifetime groups that are each determined by a dominant Standard Model quark substate.

Malcolm H. Mac Gregor

2006-07-20T23:59:59.000Z

265

Mercury's Protoplanetary Mass  

E-Print Network (OSTI)

Major element fractionation among chondrites has been discussed for decades as ratios relative to Si or Mg. Recently, by expressing ratios relative to Fe, I discovered a new relationship admitting the possibility that ordinary chondrite meteorites are derived from two components, a relatively oxidized and undifferentiated, primitive component and a somewhat differentiated, planetary component, with oxidation state like the highly reduced enstatite chondrites, which I suggested was identical to Mercury's complement of lost elements. Here, on the basis of that relationship, I derive expressions, as a function of the mass of planet Mercury and the mass of its core, to estimate the mass of Mercury's lost elements, the mass of Mercury's alloy and rock protoplanetary core, and the mass of Mercury's gaseous protoplanet. Although Mercury's mass is well known, its core mass is not, being widely believed to be in the range of 70-80 percent of the planet mass. For a core mass of 75 percent, the mass of Mercury's lost elements is about 1.32 times the mass of Mercury, the mass of the alloy and rock protoplanetary core is about 2.32 times the mass of Mercury, and the mass of the gaseous protoplanet of Mercury is about 700 times the mass of Mercury. Circumstantial evidence is presented in support of the supposition that Mercury's lost elements is identical to the planetary component of ordinary chondrite formation.

J. Marvin Herndon

2004-10-01T23:59:59.000Z

266

Atomic vapor laser isotope separation  

SciTech Connect

Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power reactor fuel has been under development for over 10 years. In June 1985 the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for the internationally competitive production of uranium separative work. The economic basis for this decision is considered, with an indicated of the constraints placed on the process figures of merit and the process laser system. We then trace an atom through a generic AVLIS separator and give examples of the physical steps encountered, the models used to describe the process physics, the fundamental parameters involved, and the role of diagnostic laser measurements.

Stern, R.C.; Paisner, J.A.

1985-11-08T23:59:59.000Z

267

Sensitivity of the Simulated Distributions of Water Masses, CFCs, and Bomb 14C to Parameterizations of Mesoscale Tracer Transports in a Model of the North Pacific  

Science Conference Proceedings (OSTI)

A basinwide ocean general circulation model of the North Pacific Ocean is used to study the sensitivity of the simulated distributions of water masses, chlorofluorocarbons (CFCs), and bomb carbon-14 isotope (14C) to parameterizations of mesoscale ...

Yongfu Xu; Shigeaki Aoki; Koh Harada

2006-03-01T23:59:59.000Z

268

Isotope separation by photoselective dissociative electron capture  

DOE Patents (OSTI)

A method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, .sup.235 UF.sub.6 is separated from a UF.sub.6 mixture by selective excitation followed by dissociative electron capture into .sup.235 UF.sub.5 - and F.

Stevens, Charles G. (Pleasanton, CA)

1978-01-01T23:59:59.000Z

269

Isotope separation by photoselective dissociative electron capture  

DOE Patents (OSTI)

Disclosed is a method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, [sup 235]UF[sub 6] is separated from a UF[sub 6] mixture by selective excitation followed by dissociative electron capture into [sup 235]UF[sub 5]- and F. 2 figs.

Stevens, C.G.

1978-08-29T23:59:59.000Z

270

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

E-Print Network (OSTI)

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.

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

271

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

E-Print Network (OSTI)

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.

Houshia, Orwa Jaber

2012-01-01T23:59:59.000Z

272

Tritium Isotope Separation Using Adsorption-Distillation Column  

Science Conference Proceedings (OSTI)

Technical Paper / Tritium Science and Technology - Tritium Science and Technology - Detritiation, Purification, and Isotope Separation

Satoshi Fukada

273

FISSION HALF LIVES OF FERMIUM ISOTOPES WITHIN SKYRME HARTREE-FOCK-BOGOLIUBOV THEORY  

Science Conference Proceedings (OSTI)

Nuclear fission barriers, mass parameters and spontaneous fission half lives of fermium isotopes calculated in a framework of the Skyrme Hartree-Fock-Bogoliubov model with the SkM* force are discussed. Zero-point energy corrections in the ground state are determined for each nucleus using the Gaussian overlap approximation of the generator coordinate method and in the cranking formalism. Results of spontaneous fission half lives are compared to experimental data.

Baran, A. [Maria Curie-Sklodowska University; Staszczak, Andrzej [ORNL; Nazarewicz, A. [Oak Ridge National Laboratory (ORNL)

2011-01-01T23:59:59.000Z

274

Preface to bLithium isotope geochemistryQ The use of light stable isotopes to elucidate Earth  

E-Print Network (OSTI)

Li reflect heavier isotopic ratios. Chemical Geology 212 (2004) 1­4 wwwPreface Preface to bLithium isotope geochemistryQ The use of light stable isotopes to elucidate isotope geochemistry. Taylor and Urey (1938) used ion exchange chromatography to sepa- rate 6 Li from 7 Li

Rudnick, Roberta L.

275

Water isotopes in CCSM for studying water cycles in the climate system David Noone* (dcn@caltech.edu)  

E-Print Network (OSTI)

be applied to each phase change modeled in CCSM (Fig. 1). When phase change occurs slowly (evaporation from is formed rapidly and is removed from the system (such as ice formation in convective clouds follows simple "bulk" parameterizations like those used in other isotopic GCMs. Various improvements

Noone, David

276

Theoretical Mass Spectrometry  

Science Conference Proceedings (OSTI)

... Mass spectrometry is an important technique in analytical chemistry, essential in areas including drug development, criminal ... Facilities/Tools Used: ...

2013-03-19T23:59:59.000Z

277

Isotopically engineered semiconductors: from the bulk tonanostructures  

SciTech Connect

Research performed with semiconductors with controlled isotopic composition is evolving from the measurement of fundamental properties in the bulk to those measured in superlattices and nanostructures. This is driven in part by interests associated with the fields of 'spintronics' and quantum computing. In this topical review, which is dedicated to Prof. Abstreiter, we introduce the subject by reviewing classic and recent measurements of phonon frequencies, thermal conductivity, bandgap renormalizations, and spin coherence lifetimes in isotopically controlled bulk group IV semiconductors. Next, we review phonon properties measured in isotope heterostructures, including pioneering work made possible by superlattices grown by the group of Prof. Abstreiter. We close the review with an outlook on the exciting future possibilities offered through isotope control in 1, 2, and 3 dimensions that will be possible due to advances in nanoscience.

Ager III, Joel W.; Haller, Eugene E.

2006-04-07T23:59:59.000Z

278

Atomic vapor laser isotope separation process  

DOE Patents (OSTI)

A laser spectroscopy system is utilized in an atomic vapor laser isotope separation process. The system determines spectral components of an atomic vapor utilizing a laser heterodyne technique. 23 figs.

Wyeth, R.W.; Paisner, J.A.; Story, T.

1990-08-21T23:59:59.000Z

279

Stable isotope investigations of chlorinated aliphatic hydrocarbons.  

Science Conference Proceedings (OSTI)

Stable isotope ratio measurements for carbon (C) and chlorine (Cl) can be used to elucidate the processes affecting transformation and transportation of chlorinated aliphatic hydrocarbons (CAHs) in the environment. Methods recently developed in our laboratory for isotopic analysis of CAHs have been applied to laboratory measurements of the kinetic isotope effects associated with aerobic degradation of dichloromethane (DCM) and with both anaerobic and aerobic cometabolic degradation of trichlomethene (TCE) in batch and column microbial cultures. These experimental determinations of fractionation factors are crucial for understanding the behavior of CAHs in complex natural systems, where the extent of biotransformation can be masked by dispersion and volatilization. We have also performed laboratory investigations of kinetic isotope effects accompanying evaporation of CAHs, as well as field investigations of natural attenuation and in situ remediation of CAHs in a number of contaminated shallow aquifers at sites operated by the federal government and the private sector.

Abrajano, T.; Heraty, L. J.; Holt, B. D.; Huang, L.; Sturchio, N. C.

1999-06-01T23:59:59.000Z

280

Elbow mass flow meter  

SciTech Connect

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.

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

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Isotope shift on the chlorine electron affinity revisited by an MCHF/CI approach  

E-Print Network (OSTI)

Today, the electron affinity is experimentally well known for most of the elements and is a useful guideline for developing ab initio computational methods. However, the measurements of isotope shifts on the electron affinity are limited by both resolution and sensitivity. In this context, theory eventually contributes to the knowledge and understanding of atomic structures, even though correlation plays a dominant role in negative ions properties and, particularly, in the calculation of the specific mass shift contribution. The present study solves the longstanding discrepancy between calculated and measured specific mass shifts on the electron affinity of chlorine (Phys. Rev. A 51 (1995) 231)

Carette, Thomas

2013-01-01T23:59:59.000Z

282

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

DOE Green Energy (OSTI)

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.

Shanahan, K.

2009-10-01T23:59:59.000Z

283

Equatorward Pathways of Solomon Sea Water Masses and Their Modifications  

Science Conference Proceedings (OSTI)

The Solomon Sea is a key region of the southwest Pacific Ocean, connecting the thermocline subtropics to the equator via western boundary currents (WBCs). Modifications to water masses are thought to occur in this region because of the significant ...

Angélique Melet; Jacques Verron; Lionel Gourdeau; Ariane Koch-Larrouy

2011-04-01T23:59:59.000Z

284

Iron isotopic fractionation during continental weathering  

SciTech Connect

The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

Fantle, Matthew S.; DePaolo, Donald J.

2003-10-01T23:59:59.000Z

285

Exotic fission properties of highly neutron-rich Uranium isotopes  

E-Print Network (OSTI)

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.

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

2007-03-05T23:59:59.000Z

286

The contrasting fission potential-energy structure of actinides and mercury isotopes  

E-Print Network (OSTI)

Fission-fragment mass distributions are asymmetric in fission of typical actinide nuclei for nucleon number $A$ in the range $228 \\lnsim A \\lnsim 258$ and proton number $Z$ in the range $90\\lnsim Z \\lnsim 100$. For somewhat lighter systems it has been observed that fission mass distributions are usually symmetric. However, a recent experiment showed that fission of $^{180}$Hg following electron capture on $^{180}$Tl is asymmetric. We calculate potential-energy surfaces for a typical actinide nucleus and for 12 even isotopes in the range $^{178}$Hg--$^{200}$Hg, to investigate the similarities and differences of actinide compared to mercury potential surfaces and to what extent fission-fragment properties, in particular shell structure, relate to the structure of the static potential-energy surfaces. Potential-energy surfaces are calculated in the macroscopic-microscopic approach as functions of fiveshape coordinates for more than five million shapes. The structure of the surfaces are investigated by use of an immersion technique. We determine properties of minima, saddle points, valleys, and ridges between valleys in the 5D shape-coordinate space. Along the mercury isotope chain the barrier heights and the ridge heights and persistence with elongation vary significantly and show no obvious connection to possible fragment shell structure, in contrast to the actinide region, where there is a deep asymmetric valley extending from the saddle point to scission. The mechanism of asymmetric fission must be very different in the lighter proton-rich mercury isotopes compared to the actinide region and is apparently unrelated to fragment shell structure. Isotopes lighter than $^{192}$Hg have the saddle point blocked from a deep symmetric valley by a significant ridge. The ridge vanishes for the heavier Hg isotopes, for which we would expect a qualitatively different asymmetry of the fragments.

Takatoshi Ichikawa; Akira Iwamoto; Peter Möller; Arnold J. Sierk

2012-03-09T23:59:59.000Z

287

Method for correcting for isotope burn-in effects in fission neutron dosimeters  

DOE Patents (OSTI)

A method is described for correcting for effect of isotope burn-in in fission neutron dosimeters. Two quantities are measured in order to quantify the "burn-in" contribution, namely P.sub.Z',A', the amount of (Z', A') isotope that is burned-in, and F.sub.Z', A', the fissions per unit volume produced in the (Z', A') isotope. To measure P.sub.Z', A', two solid state track recorder fission deposits are prepared from the very same material that comprises the fission neutron dosimeter, and the mass and mass density are measured. One of these deposits is exposed along with the fission neutron dosimeter, whereas the second deposit is subsequently used for observation of background. P.sub.Z', A' is then determined by conducting a second irradiation, wherein both the irradiated and unirradiated fission deposits are used in solid state track recorder dosimeters for observation of the absolute number of fissions per unit volume. The difference between the latter determines P.sub.Z', A' since the thermal neutron cross section is known. F.sub.Z', A' is obtained by using a fission neutron dosimeter for this specific isotope, which is exposed along with the original threshold fission neutron dosimeter to experience the same neutron flux-time history at the same location. In order to determine the fissions per unit volume produced in the isotope (Z', A') as it ingrows during the irradiation, B.sub.Z', A', from these observations, the neutron field must generally be either time independent or a separable function of time t and neutron energy E.

Gold, Raymond (Richland, WA); McElroy, William N. (Richland, WA)

1988-01-01T23:59:59.000Z

288

ON THE OXYGEN ISOTOPIC COMPOSITION OF THE SOLAR SYSTEM  

SciTech Connect

The {sup 18}O/{sup 17}O ratio of the solar system is 5.2 while that of the interstellar medium (ISM) and young stellar objects is approx4. This difference cannot be explained by pollution of the Sun's natal molecular cloud by {sup 18}O-rich supernova ejecta because (1) the necessary B-star progenitors live longer than the duration of star formation in molecular clouds, (2) the delivery of ejecta gas is too inefficient and the amount of dust in supernova ejecta is too small compared to the required pollution (2% of total mass or approx20% of oxygen), and (3) the predicted amounts of concomitant short-lived radionuclides (SLRs) conflicts with the abundances of {sup 26}Al and {sup 41}Ca in the early solar system. Proposals for the introduction of {sup 18}O-rich material must also be consistent with any explanation for the origin of the observed slope-one relationship between {sup 17}O/{sup 16}O and {sup 18}O/{sup 16}O in the high-temperature components of primitive meteorites. The difference in {sup 18}O/{sup 17}O ratios can be explained by enrichment of the ISM by the {sup 17}O-rich winds of asymptotic giant branch (AGB) stars, the sequestration of comparatively {sup 18}O-rich gas from star-forming regions into long-lived, low-mass stars, and a monotonic decrease in the {sup 18}O/{sup 17}O ratio of interstellar gas. At plausible rates of star formation and gas infall, Galactic chemical evolution does not follow a slope-one line in a three-isotope plot, but instead moves along a steeper trajectory toward an {sup 17}O-rich state. Evolution of the ISM and star-forming gas by AGB winds also explains the difference in the carbon isotope ratios of the solar system and ISM.

Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, Honolulu, HI, 96822 (United States); Krot, Alexander N.; Huss, Gary R., E-mail: gaidos@hawaii.ed, E-mail: sasha@higp.hawaii.ed, E-mail: huss@higp.hawaii.ed [Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, HI, 96822 (United States)

2009-11-10T23:59:59.000Z

289

Greenland Ice Sheet Mass Balance Reconstruction. Part III: Marine Ice Loss and Total Mass Balance (1840–2010)  

Science Conference Proceedings (OSTI)

Greenland ice sheet mass loss to the marine environment occurs by some combination of iceberg calving and underwater melting (referred to here as marine ice loss, LM). This study quantifies the relation between LM and meltwater runoff (R) at the ...

Jason E. Box; William Colgan

2013-09-01T23:59:59.000Z

290

Greenland ice sheet mass balance reconstruction. Part III: marine ice loss and total mass balance (1840-2010)  

Science Conference Proceedings (OSTI)

Greenland ice sheet mass loss to the marine environment occurs by some combination of iceberg calving and underwater melting (referred to here as marine ice loss, LM). This study quantifies the relation between LM and meltwater runoff (R) at the ...

Jason E. Box; William Colgan

291

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

Science Conference Proceedings (OSTI)

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.

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

2011-03-01T23:59:59.000Z

292

Final Report, NEAC Subcommittee for Isotope Research & Production Planning  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Final Report, NEAC Subcommittee for Isotope Research & Production Final Report, NEAC Subcommittee for Isotope Research & Production Planning Final Report, NEAC Subcommittee for Isotope Research & Production Planning Isotopes, including both radioactive and stable isotopes, make important contributions to research, medicine, and industry in the United States and throughout the world. For nearly fifty years, the Department of Energy (DOE) has actively promoted the use of isotopes by funding (a) production of isotopes at a number of national laboratories with unique nuclear reactors or particle accelerators, (b) nuclear medicine research at the laboratories and in academia, (c) research into industrial applications of isotopes, and (d) research into isotope production and processing methods. The radio- pharmaceutical and radiopharmacy industries have their origin in

293

A post accelerator for the U.S. rare isotope accelerator facility.  

SciTech Connect

The proposed Rare Isotope Accelerator (RIA) Facility includes a post-accelerator for rare isotopes (RIB linac) which must produce high-quality beams of radioactive ions over the full mass range, including uranium, at energies above the coulomb barrier, and have high transmission and efficiency. The latter requires the RIB linac to accept at injection ions in the 1+ charge state. A concept for such a post accelerator suitable for ions up to mass 132 has been previously described [1]. This paper presents a modified concept which extends the mass range to uranium. A high resolution separator for purifying beams at the isobaric level precedes the RIB linac. The mass filtering process will provide high purity beams while preserving transmission. For most cases a resolution of about m/{Delta}m=20,000 is adequate at mass A=100 to obtain a separation between isobars of mass excess difference of 5 MeV. The design for a device capable of purifying beams at the isobaric level included calculations up to 5th order. The RIB linac will utilize existing superconducting heavy-ion linac technology for all but a small portion of the accelerator system. The exceptional piece, a very-low-charge-state injector, section needed for just the first few MV of the RIB accelerator, consists of a pre-buncher followed by several sections of cw, normally-conducting RFQ. Two stages of charge stripping are provided: helium gas stripping at energies of a few keV/u, and additional foil stripping at {approx}680 keV/u for the heavier ions. In extending the mass range to uranium, however, for best efficiency the helium gas stripping must be performed at different energies for different mass ions. We present numerical simulations of the beam dynamics of a design for the complete RIB linac which provides for several stripping options and uses cost-effective solenoid focusing elements in the drift-tube linac.

Ostroumov, P. N.; Kelly, M. P.; Kolomiets, A. A.; Nolen, J. A.; Portillo, M.; Shepard, K. W.; Vinogradov, N. E.

2002-06-11T23:59:59.000Z

294

The Enriched Background Isotope Study (EBIS)  

SciTech Connect

A unique, large release of radiocarbon occurred near the Oak Ridge Reservation (ORR), Oak Ridge, TN in July/August 1999. Measurements of 14C in tree ring cellulose throughout the ORR area demonstrate that the 1999 release was unprecedented in its uptake by vegetation. We are taking advantage of the whole-ecosystem isotopic label generated by this release to address five outstanding issues in the terrestrial carbon cycle: (1) partitioning of soil respiration between autotrophic and heterotrophic sources, and quantification of that partitioning seasonally and inter-annually, (2) partitioning of heterotrophic respiration sources between above-ground litter decomposition and below-ground root detritus decomposition, (3) identification of pathways leading from leaf and root detritus to long-term stabilization of soil organic matter, including the role of soil fauna, (4) the role of dissolved organic carbon (DOC) transport in distributing carbon within the soil profile, and (5) the longevity and turnover time of fine roots. The first four issues are being addressed through a reciprocal litter transplant experiment set up at four sites on the ORR encompassing two soil types and two levels of 14C exposure in 1999. The fifth issue, longevity and turnover of fine roots, is being addressed by tracing the radiocarbon label through the fine root pool over time. With a combination of incubation, soil surface chamber and soil CO2 profiles, and continuous measurements of soil temperature and moisture controls, we are tracking changes in soil respiration partitioning over several years. The nature and source of organic matter pools that reside in soils for years to decades are being tracked with differently labeled root and surface litter, and experiments to exclude soil fauna have been initiated to elucidate their role in vertical transport. Periodic sampling of soils and soil solutions and the use of inert tracers, allow us to investigate the chemical nature and form of DOC and its transport in surface soil horizons. Results from these field observations will be used to parameterize and refine existing carbon dynamics models. Such models will then be used to quantitatively address the long-term fate of ecosystem carbon inputs and the potential for ecosystem carbon sequestration.

Paul J. Hanson; Susan Trumbore; Chris Swanston; Margaret Torn; Julie Jastrow; William A. Parton; Wilfred M. Post; Mats J. Fröberg; Laura J. Hainsworth; Markus Kleber; Christiane Kramer; Roser Matamala-Paradeda; Charles T. Garten Jr.

2007-02-05T23:59:59.000Z

295

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

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.

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

1993-01-01T23:59:59.000Z

296

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

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.

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

1993-02-23T23:59:59.000Z

297

Small system for tritium accelerator mass spectrometry  

DOE Patents (OSTI)

This invention is comprised of an apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radiofrequency 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.

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

1991-12-31T23:59:59.000Z

298

A new detector setup for ISOLTRAP and test of the Isobaric Multiplet Mass Equation  

E-Print Network (OSTI)

Installed at the on-line isotope separator ISOLDE at CERN, the tandem Penning-trap spectrometer ISOLTRAP is designed to perform high-accuracy mass measurements on short-lived radionuclides. Based on the determination of the ion cyclotron frequency $\

Yazidjian, Chabouh; Ban, Gilles

2006-01-01T23:59:59.000Z

299

Mass-Loaded Flows  

E-Print Network (OSTI)

A key process within astronomy is the exchange of mass, momentum, and energy between diffuse plasmas in many types of astronomical sources (including planetary nebulae, wind-blown bubbles, supernova remnants, starburst superwinds, and the intracluster medium) and dense, embedded clouds or clumps. This transfer affects the large scale flows of the diffuse plasmas as well as the evolution of the clumps. I review our current understanding of mass-injection processes, and examine intermediate-scale structure and the global effect of mass-loading on a flow. I then discuss mass-loading in a variety of diffuse sources.

J. M. Pittard

2006-07-13T23:59:59.000Z

300

Does Information Have Mass?  

E-Print Network (OSTI)

Does information have mass? This question has been asked many times and there are many answers even on the Internet, including on Yahoo Answers. Usually the answer is "no". Attempts have been made to assess the physical mass of information by estimating the mass of electrons feeding the power-guzzling computers and devices making up the Internet, the result being around 50 gram. Other efforts to calculate the mass of information have assumed that each electron involved in signal transfer carries one bit of information, which makes the corresponding mass to be about 10^-5 gram. We address the fundamental question of minimum mass related to a bit of information from the angles of quantum physics and special relativity. Our results indicate that there are different answers depending on the physical situation, and sometimes the mass can even be negative. We tend to be skeptical about the earlier mass estimations, mentioned above, because our results indicate that the electron's mass does not play a role in any on...

Kish, Laszlo B

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Nuclear Masses in Astrophysics  

E-Print Network (OSTI)

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.

Christine Weber; Klaus Blaum; Hendrik Schatz

2008-12-09T23:59:59.000Z

302

Laser Isotope Separation Employing Condensation Repression  

SciTech Connect

Molecular laser isotope separation (MLIS) techniques using condensation repression (CR) harvesting are reviewed and compared with atomic vapor laser isotope separation (AVLIS), gaseous diffusion (DIF), ultracentrifuges (UCF), and electromagnetic separations (EMS). Two different CR-MLIS or CRISLA (Condensation Repression Isotope Separation by Laser Activation) approaches have been under investigation at the University of Missouri (MU), one involving supersonic super-cooled free jets and dimer formation, and the other subsonic cold-wall condensation. Both employ mixtures of an isotopomer (e.g. {sup i}QF{sub 6}) and a carrier gas, operated at low temperatures and pressures. Present theories of VT relaxation, dimerization, and condensation are found to be unsatisfactory to explain/predict experimental CRISLA results. They were replaced by fundamentally new models that allow ab-initio calculation of isotope enrichments and predictions of condensation parameters for laser-excited and non-excited vapors which are in good agreement with experiment. Because of supersonic speeds, throughputs for free-jet CRISLA are a thousand times higher than cold-wall CRISLA schemes, and thus preferred for large-quantity Uranium enrichments. For small-quantity separations of (radioactive) medical isotopes, the simpler coldwall CRISLA method may be adequate.

Eerkens, Jeff W.; Miller, William H.

2004-09-15T23:59:59.000Z

303

Higgs boson masses in supersymmetric models  

SciTech Connect

Imposing supersymmetry on a Higgs potential constrains the parameters that define the potential. In supersymmetric extensions to the stranded model containing only Higgs SU(2){sub L} doublets there exist Higgs boson mass sum rules and bounds on the Higgs masses at tree level. The prescription for renormalizing these sum rules is derived. An explicit calculation is performed in the minimal supersymmetric extension to the standard model (MSSM). In this model at tree level the mass sum rule is M{sub H}{sup 2} + M{sub h}{sup 2} = M{sub A}{sup 2} + M{sub Z}{sup 2}. The results indicate that large corrections to the sum rules may arise from heavy matter fields, e.g. a heavy top quark. Squarks significantly heavier than their fermionic partners contribute large contributions when mixing occurs in the squark sector. These large corrections result from squark-Higgs couplings that become large in this limit. Contributions to individual Higgs boson masses that are quadratic in the squark masses cancel in the sum rule. Thus the naturalness constraint on Higgs boson masses is hidden in the combination of Higgs boson masses that comprise the sum rule. 39 refs., 13 figs.

Berger, M.S.

1991-04-01T23:59:59.000Z

304

CARBON ISOTOPE STRATIGRAPHY AND DIAGENESIS OF PENNSYLVANIAN (DESMOINESIAN-MISSOURIAN) CARBONATES IN EAST-CENTRAL IDAHO  

E-Print Network (OSTI)

Carbon isotope stratigraphy of carbonate sediments is instrumental in examining major perturbations in the global carbon cycle and in correlating strata. However, the primary isotopic signal recorded in these sediments can vary with depositional environment and diagenetic alteration. This study examines the carbon isotope stratigraphy and its relation to depositional environment, lithology, and diagenetic history in a section of the 312-307 million year old Pennsylvanian (Desmoinesian-Missourian) Snaky Canyon Formation in the Beaverhead Mountains, east-central Idaho. Petrography of 90 thin sections show carbonate rocks ranging from mudstone to boundstone containing variable amounts of eolian siliciclastics with as much as 50% silt to medium sand grains in some samples. The abundance of siliciclastic influx decreases upsection to less than 1% sand and roughly corresponds to an increase in parasequence thickness. Open marine carbonate facies include abundant crinoids, bryozoans, foraminifera, brachiopods, green algae, phylloid algae, and arthropod fragments. Chert, bioturbation features (e.g. burrows), intraclasts, pellets, coarse calcite spar, calcite-filled fractures, and fossil silicification also occur in these rocks. Cathodoluminescence (CL) analysis of thin sections reveals a lack of luminescence in nearly all components, suggesting that depositional and diagenetic waters were low in Mn2+ or high in Fe2+. Approximately 130 billets were analyzed to yield 13C/12C and 18O/16O ratios. Fractures have much lower ?18O (-13.9‰)reflecting post-depositional tectonic processes. Most of the isotopic data for micritic components are within -8 to -1‰ for ?18O and -1 to +5‰ for ?13C. Previously reported oxygen isotope values for Pennsylvanian brachiopods from the U.S. Midcontinent are -2.2 ±0.7‰, indicating outlier ?18O values in this study are altered. Most of the isotope data for carbon are within previously reported Pennsylvanian fine grained carbonate ranges of +1 to +5‰. These isotopic values appear to be independent of lithology and percent carbonate; thus, the main controlling influence on the ?13C and ?18O data may be depositional environment. Three significant trends in the ?13C data appear to correspond to thickness and boundaries of stratigraphic parasequences. Isotope values in this study were compared to those of Arrow Canyon,Nevada and showed similar trends for the Desmoinesian but not for the Missourian.

Wood, Stephanie

2011-05-01T23:59:59.000Z

305

Fission modes of mercury isotopes  

E-Print Network (OSTI)

Background: Recent experiments on beta-delayed fission in the mercury-lead region and the discovery of asym- metric fission in 180 Hg [1] have stimulated theoretical interest in the mechanism of fission in heavy nuclei. Purpose: We study fission modes and fusion valleys in 180 Hg and 198 Hg to reveal the role of shell effects in pre-scission region and explain the experimentally observed fragment mass asymmetry and its variation with A. Methods: We use the self-consistent nuclear density functional theory employing Skyrme and Gogny energy density functionals. Results: The potential energy surfaces in multi-dimensional space of collective coordinates, including elongation, triaxiality, reflection-asymmetry, and necking, are calculated for 180 Hg and 198 Hg. The asymmetric fission valleys - well separated from fusion valleys associated with nearly spherical fragments - are found in in both cases. The density distributions at scission configurations are studied and related to the experimentally observed mass splits. Conclusions: The energy density functionals SkM\\ast and D1S give a very consistent description of the fission process in 180 Hg and 198 Hg. We predict a transition from asymmetric fission in 180 Hg towards more symmetric distribution of fission fragments in 198 Hg. For 180 Hg, both models yield 100 Ru/80 Kr as the most probable split. For 198 Hg, the most likely split is 108 Ru/90 Kr in HFB-D1S and 110 Ru/88 Kr in HFB-SkM\\ast.

M. Warda; A. Staszczak; W. Nazarewicz

2012-05-25T23:59:59.000Z

306

Fission Modes of Mercury Isotopes  

Science Conference Proceedings (OSTI)

Background: Recent experiments on -delayed fission in the mercury-lead region and the discovery of asymmetric fission in 180Hg [A. N. Andreyev et al., Phys. Rev. Lett. 105, 252502 (2010)] have stimulated theoretical interest in the mechanism of fission in heavy nuclei. Purpose: We study fission modes and fusion valleys in 180Hg and 198Hg to reveal the role of shell effects in the prescission region and explain the experimentally observed fragment mass asymmetry and its variation with A. Methods: We use the self-consistent nuclear density functional theory employing Skyrme and Gogny energy density functionals. Results: The potential energy surfaces in multidimensional space of collective coordinates, including elongation, triaxiality, reflection-asymmetry, and necking, are calculated for 180Hg and 198Hg. The asymmetric fission valleys well separated from fusion valleys associated with nearly spherical fragments are found in both cases. The density distributions at scission configurations are studied and related to the experimentally observed mass splits. Conclusions: The energy density functionals SkM and D1S give a very consistent description of the fission process in 180Hg and 198Hg. We predict a transition from asymmetric fission in 180Hg toward a more symmetric distribution of fission fragments in 198Hg. For 180Hg, both models yield 100Ru/80Kr as the most probable split. For 198Hg, the most likely split is 108Ru/90Kr in HFB-D1S and 110Ru/88Kr in HFB-SkM .

Warda, M. [Maria Curie-Sk?odowska University-Poland; Staszczak, A. [Maria Curie-Sklodowska University; Nazarewicz, Witold [UTK/ORNL/University of Warsaw

2012-01-01T23:59:59.000Z

307

REPORT OF SURVEY OF OAK RIDGE ISOTOPE  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

OAK RIDGE ISOTOPE OAK RIDGE ISOTOPE ENRICHMENT (CALUTRON) FACILITY BUILDING 9204-3 U.S. Department of Energy Office of Environmental Management & Office of Nuclear Energy Report of Survey of Oak Ridge Isotope Enrichment (Calutron) Facility Building 9204-3 FINAL May 8, 2000 Contents 1. Introduction 1.1 Purpose 1.2 Facility Description 1.3 Organization Representatives 1.4 Survey Participants 2. Summary, Conclusions & Recommendations 2.1 Transfer Considerations 2.2 Post-Transfer EM Path Forward & Management Risk 3. Survey Results 4. Stabilization and Other Actions Required for Transfer 5. Surveillance & Maintenance After Transfer 6. Other Transfer Details 7. Attachments and References Appendix A - Detailed Survey Notes

308

The rare isotope accelerator (RIA) facility project  

DOE Green Energy (OSTI)

The envisioned Rare-Isotope Accelerator (RIA) facility would add substantially to research opportunities for nuclear physics and astrophysics by combining increased intensities with a greatly expanded variety of high-quality rare-isotope beams. A flexible superconducting driver linac would provide 100 kW, 400 MeV/nucleon beams of any stable isotope from hydrogen to uranium onto production targets. Combinations of projectile fragmentation, target fragmentation, fission, and spallation would produce the needed broad assortment of short-lived secondary beams. This paper describes the project's background, purpose, and status, the envisioned facility, and the key subsystem, the driver linac. RIA's scientific purposes are to advance current theoretical models, reveal new manifestations of nuclear behavior, and probe the limits of nuclear existence [3]. Figures 1 and 2 show, respectively, examples of RIA research opportunities and the yields projected for pursuing them. Figure 3 outlines a conceptual approach for delivering the needed beams.

Christoph Leemann

2000-08-01T23:59:59.000Z

309

Atomic line emission analyzer for hydrogen isotopes  

DOE Patents (OSTI)

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.

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

1993-01-01T23:59:59.000Z

310

Apparatus for separating and recovering hydrogen isotopes  

DOE Patents (OSTI)

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.

Heung, Leung K. (Aiken, SC)

1994-01-01T23:59:59.000Z

311

Atomic line emission analyzer for hydrogen isotopes  

DOE Patents (OSTI)

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.

Kronberg, J.W.

1991-05-08T23:59:59.000Z

312

Atomic line emission analyzer for hydrogen isotopes  

DOE Patents (OSTI)

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.

Kronberg, J.W.

1993-03-30T23:59:59.000Z

313

Isotope Shift Measurements of Stable and Short-Lived Lithium Isotopes for Nuclear Charge Radii Determination  

E-Print Network (OSTI)

Changes in the mean-square nuclear charge radii along the lithium isotopic chain were determined using a combination of precise isotope shift measurements and theoretical atomic structure calculations. Nuclear charge radii of light elements are of high interest due to the appearance of the nuclear halo phenomenon in this region of the nuclear chart. During the past years we have developed a new laser spectroscopic approach to determine the charge radii of lithium isotopes which combines high sensitivity, speed, and accuracy to measure the extremely small field shift of an 8 ms lifetime isotope with production rates on the order of only 10,000 atoms/s. The method was applied to all bound isotopes of lithium including the two-neutron halo isotope Li-11 at the on-line isotope separators at GSI, Darmstadt, Germany and at TRIUMF, Vancouver, Canada. We describe the laser spectroscopic method in detail, present updated and improved values from theory and experiment, and discuss the results.

Nörtershäuser, W; Ewald, G; Dax, A; Behr, J; Bricault, P; Bushaw, B A; Dilling, J; Dombsky, M; Drake, G W F; Götte, S; Kluge, H -J; Kühl, Th; Lassen, J; Levy, C D P; Pachucki, K; Pearson, M; Puchalski, M; Wojtaszek, A; Yan, Z -C; Zimmermann, C

2010-01-01T23:59:59.000Z

314

On the Photon Mass  

E-Print Network (OSTI)

We review the case for the photon having a tiny mass compatible with the experimental limits. We go over some possible experimental tests for such a photon mass including the violation of Lorentz symmetry. We point out that such violations may already have been witnessed in tests involving high energy gamma rays from outer space as also ultra high energy cosmic rays.

Burra G. Sidharth

2007-06-22T23:59:59.000Z

315

Thermal masses in leptogenesis  

E-Print Network (OSTI)

We investigate the validity of using thermal masses in the kinematics of final states in the decay rate of heavy neutrinos in leptogenesis calculations. We find that using thermal masses this way is a reasonable approximation, but corrections arise through quantum statistical distribution functions and leptonic quasiparticles.

Kiessig, Clemens P

2009-01-01T23:59:59.000Z

316

The origin of mass  

Science Conference Proceedings (OSTI)

The origin of mass is one of the deepest mysteries in science. Neutrons and protons, which account for almost all visible mass in the Universe, emerged from a primordial plasma through a cataclysmic phase transition microseconds after the Big Bang. However, ... Keywords: Gordon Bell Prize categories: scalability and time to solution, SC13 proceedings

Peter Boyle, Michael I. Buchoff, Norman Christ, Taku Izubuchi, Chulwoo Jung, Thomas C. Luu, Robert Mawhinney, Chris Schroeder, Ron Soltz, Pavlos Vranas, Joseph Wasem

2013-11-01T23:59:59.000Z

317

Elbow mass flow meter  

DOE Patents (OSTI)

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. 3 figs.

McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.

1994-08-16T23:59:59.000Z

318

W Transverse Mass  

NLE Websites -- All DOE Office Websites (Extended Search)

Some Data Analysis Some Data Analysis The Tevatron produces millions of collisions each second in CDF and DZero. The detectors have hardware triggers to decide if a collision is "interesting," that is it contains a candidate event for any one of a number studies. Our dataset contains 48,844 candidate events for a W mass study. There are other datasets to study Z mass, top and b quarks, QCD, etc. Why don't all the W decays give exactly the same mass? Are all these candidates really Ws? What if we chose only some of these data. How would our choice effect the value of the transverse mass? Work with your classmates. Test the data to see what you can learn. Help with data analysis. Record the best estimate of the W transverse mass from your data analysis. Explain which data you used and why. Check with your classmates and explain any differences between your estimate and theirs.

319

Method for production of an isotopically enriched compound  

Science Conference Proceedings (OSTI)

A method is presented for producing and isolating an isotopically enriched compound of a desired isotope from a parent radionuclide. The method includes forming, or placing, a precipitate containing a parent radionuclide of the desired daughter isotope in a first reaction zone and allowing sufficient time for the parent to decay into the desired gaseous daughter radioisotope. The method further contemplates collecting the desired daughter isotope as a solid in a second reaction zone through the application of temperatures below the freezing point of the desired isotope to a second reaction zone that is connected to the first reaction zone. Specifically, a method is presented for producing isotopically enriched compounds of xenon, including the radioactive isotope Xe-131m and the stable isotope Xe-131.

Watrous, Matthew G.

2012-12-11T23:59:59.000Z

320

MassMass transfer andtransfer and arationstearationste  

E-Print Network (OSTI)

, temperature, T, and energy, E, are scalars and their gradient is a vector dc/dx or arationste scalars diffusion coefficient D; for species A in medium B : D = DAB 4 erföringo dx dc D dt.A dm m Massöve c cSepa dx dc )DD(m th Irreversible Thermodynamics considers Thermo-diffusion 4 erföringo T T Thermo

Zevenhoven, Ron

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Facility for Endurance Testing of Hydrophobic Isotope Exchange Catalysts  

Science Conference Proceedings (OSTI)

Detritiation and Isotope Separation / Proceedings of the Ninth International Conference on Tritium Science and Technology (Part 2)

Lidia Matei; C. Postolache; C. Tuta; S. Brad

322

Cryogenic Adsorption of Hydrogen Isotopes over Nano-Structured Materials  

Science Conference Proceedings (OSTI)

Detritiation and Isotope Separation / Proceedings of the Ninth International Conference on Tritium Science and Technology (Part 2)

X. Xiao; L. K. Heung

323

Space isotope power program. Quarterly report, October--December 1968  

SciTech Connect

Progress during October through December 1968 in the Space Isotope Power Program at the Sandia Laboratories is reported. (LCL)

1969-02-01T23:59:59.000Z

324

Isotopic Interdiffusion Analysis and its Application in Multicomponent ...  

Science Conference Proceedings (OSTI)

Presentation Title, Isotopic Interdiffusion Analysis and its Application in Multicomponent ... Calorimetric studies of lithium ion cells and their constructing materials.

325

Discovery of Scandium, Titanium, Mercury, and Einsteinium Isotopes  

E-Print Network (OSTI)

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.

D. Meierfrankenfeld; A. Bury; M. Thoennessen

2010-03-26T23:59:59.000Z

326

Isotopic Generation and Confirmation of the PWR Application Model   

SciTech Connect

The objective of this calculation is to establish an isotopic database to represent commercial spent nuclear fuel (CSNF) from pressurized water reactors (PWRs) in criticality analyses performed for the proposed Monitored Geologic Repository at Yucca Mountain, Nevada. Confirmation of the conservatism with respect to criticality in the isotopic concentration values represented by this isotopic database is performed as described in Section 3.5.3.1.2 of the ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2000). The isotopic database consists of the set of 14 actinides and 15 fission products presented in Section 3.5.2.1.1 of YMP 2000 for use in CSNF burnup credit. This set of 29 isotopes is referred to as the principal isotopes. The oxygen isotope from the UO{sub 2} fuel is also included in the database. The isotopic database covers enrichments of {sup 235}U ranging from 1.5 to 5.5 weight percent (wt%) and burnups ranging from approximately zero to 75 GWd per metric ton of uranium (mtU). The choice of fuel assembly and operating history values used in generating the isotopic database are provided is Section 5. Tables of isotopic concentrations for the 29 principal isotopes (plus oxygen) as a function of enrichment and burnup are provided in Section 6.1. Results of the confirmation of the conservatism with respect to criticality in the isotopic concentration values are provided in Section 6.2.

L.B. Wimmer

2003-11-10T23:59:59.000Z

327

Final Report on Isotope Ratio Techniques for Light Water Reactors  

SciTech Connect

The Isotope Ratio Method (IRM) is a technique for estimating the energy or plutonium production in a fission reactor by measuring isotope ratios in non-fuel reactor components. The isotope ratios in these components can then be directly related to the cumulative energy production with standard reactor modeling methods.

Gerlach, David C.; Gesh, Christopher J.; Hurley, David E.; Mitchell, Mark R.; Meriwether, George H.; Reid, Bruce D.

2009-07-01T23:59:59.000Z

328

E.L. Grossman Chapter 10 Oxygen Isotope Stratigraphy  

E-Print Network (OSTI)

are the mineral and water respectively. Oxygen isotopic ratios are The Geologic Time Scale 2012. DOI: 10.1016/B978E.L. Grossman Chapter 10 Oxygen Isotope Stratigraphy Abstract:Variations in the 18 O/16 O ratios for global correlation. Relying on previous compilations and new data, this chapter presents oxygen isotope

Grossman, Ethan L.

329

Resonance Ionization Mass Spectrometry System for Measurement of Environmental Samples  

Science Conference Proceedings (OSTI)

A resonance ionization mass spectrometry (RIMS) system has been developed at the National Institute of Standards and Technology (NIST) for sensitive and selective determination of radio?cesium in the environment. The overall efficiency was determined to be 4×10?7 with a combined (laser and mass spectrometer) selectivity of 108 for both 135Cs and 137Cs with respect to 133Cs. RIMS isotopic ratio measurements of 135Cs/ 137Cs were performed on a nuclear fuel burn?up sample and compared to measurements on a similar system at Pacific Northwest National Laboratory (PNNL) and to conventional thermal ionization mass spectrometry (TIMS). Results of preliminary RIMS investigations on a freshwater lake sediment sample are also discussed.

L. Pibida; C. A. McMahon; W. Nörtershäuser; B. A. Bushaw

2002-01-01T23:59:59.000Z

330

USE OF NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS...  

Open Energy Info (EERE)

USE OF NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE COSO EGS PROJECT Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: USE...

331

Validation of Electrochemically Modulated Separations Performed On-Line with MC-ICP-MS for Uranium and Plutonium Isotopic Analyses  

Science Conference Proceedings (OSTI)

The most time consuming process in uranium or plutonium isotopic analyses is performing the requisite chromatographic separation of the actinides. Filament preparation for thermal ionization (TIMS) adds further delays, but is generally accepted due to the unmatched performance in trace isotopic analyses. Advances in Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) are beginning to rival the performance of TIMS. Methods, such as Electrochemically Modulated Separations (EMS) can efficiently pre-concentrate U or Pu quite selectively from small solution volumes in a matrix of 0.5 M nitric acid. When performed in-line with ICP-MS, the rapid analyte release from the electrode is fast, and large transient analyte signal enhancements of >100 fold can be achieved as compared to more conventional continuous nebulization of the original starting solution. This makes the approach ideal for very low level isotope ratio measurements. In this paper, some aspects of EMS performance are described. These include low level Pu isotope ratio behavior versus concentration by MC-ICP-MS and uranium rejection characteristics that are also important for reliable low level Pu isotope ratio determinations.

Liezers, Martin; Olsen, Khris B.; Mitroshkov, Alexandre V.; Duckworth, Douglas C.

2010-08-11T23:59:59.000Z

332

Laser Isotope Enrichment for Medical and Industrial Applications  

SciTech Connect

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".

Leonard Bond

2006-07-01T23:59:59.000Z

333

A Review of Antarctic Surface Snow Isotopic Composition: Observations, Atmospheric Circulation, and Isotopic Modeling  

Science Conference Proceedings (OSTI)

A database of surface Antarctic snow isotopic composition is constructed using available measurements, with an estimate of data quality and local variability. Although more than 1000 locations are documented, the spatial coverage remains uneven ...

V. Masson-Delmotte; S. Hou; A. Ekaykin; J. Jouzel; A. Aristarain; R. T. Bernardo; D. Bromwich; O. Cattani; M. Delmotte; S. Falourd; M. Frezzotti; H. Gallée; L. Genoni; E. Isaksson; A. Landais; M. M. Helsen; G. Hoffmann; J. Lopez; V. Morgan; H. Motoyama; D. Noone; H. Oerter; J. R. Petit; A. Royer; R. Uemura; G. A. Schmidt; E. Schlosser; J. C. Simões; E. J. Steig; B. Stenni; M. Stievenard; M. R. van den Broeke; R. S. W. van de Wal; W. J. van de Berg; F. Vimeux; J. W. C. White

2008-07-01T23:59:59.000Z

334

Benchmark of SCALE (SAS2H) isotopic predictions of depletion analyses for San Onofre PWR MOX fuel  

Science Conference Proceedings (OSTI)

The isotopic composition of mixed-oxide (MOX) fuel, fabricated with both uranium and plutonium, after discharge from reactors is of significant interest to the Fissile Materials Disposition Program. The validation of the SCALE (SAS2H) depletion code for use in the prediction of isotopic compositions of MOX fuel, similar to previous validation studies on uranium-only fueled reactors, has corresponding significance. The EEI-Westinghouse Plutonium Recycle Demonstration Program examined the use of MOX fuel in the San Onofre PWR, Unit 1, during cycles 2 and 3. Isotopic analyses of the MOX spent fuel were conducted on 13 actinides and {sup 148}Nd by either mass or alpha spectrometry. Six fuel pellet samples were taken from four different fuel pins of an irradiated MOX assembly. The measured actinide inventories from those samples has been used to benchmark SAS2H for MOX fuel applications. The average percentage differences in the code results compared with the measurement were {minus}0.9% for {sup 235}U and 5.2% for {sup 239}Pu. The differences for most of the isotopes were significantly larger than in the cases for uranium-only fueled reactors. In general, comparisons of code results with alpha spectrometer data had extreme differences, although the differences in the calculations compared with mass spectrometer analyses were not extremely larger than that of uranium-only fueled reactors. This benchmark study should be useful in estimating uncertainties of inventory, criticality and dose calculations of MOX spent fuel.

Hermann, O.W.

2000-02-01T23:59:59.000Z

335

NEW TITANIUM ISOTOPE DATA FOR ALLENDE AND EFREMOVKA CAIs  

SciTech Connect

We measured the titanium (Ti) isotope composition, i.e., {sup 50}Ti/{sup 47}Ti, {sup 48}Ti/{sup 47}Ti, and {sup 46}Ti/{sup 47}Ti, in five calcium-rich-aluminum-rich refractory inclusions (CAIs) from the oxidized CV3 chondrite Allende and in two CAIs from the reduced CV3 chondrite Efremovka. Our data indicate that CAIs are enriched in {sup 50}Ti/{sup 47}Ti and {sup 46}Ti/{sup 47}Ti and are slightly depleted in {sup 48}Ti/{sup 47}Ti compared to normal Ti defined by ordinary chondrites, eucrites, ureilites, mesosiderites, Earth, Moon, and Mars. Some CAIs have an additional {sup 50}Ti excess of {approx}8{epsilon} relative to bulk carbonaceous chondrites, which are enriched in {sup 50}Ti by {approx}2{epsilon} relative to terrestrial values, leading to a total excess of {approx}10{epsilon}. This additional {sup 50}Ti excess is correlated with nucleosynthetic anomalies found in {sup 62}Ni and {sup 96}Zr, all indicating an origin from a neutron-rich stellar source. Bulk carbonaceous chondrites show a similar trend, however, the extent of the anomalies is either less than or similar to the smallest anomalies seen in CAIs. Mass balance calculations suggest that bulk Allende Ti possibly consists of a mixture of at least two Ti components, anomalous Ti located in CAIs and a normal component possibly for matrix and chondrules. This argues for a heterogeneous distribution of Ti isotopes in the solar system. The finding that anomalous Ti is concentrated in CAIs suggests that CAIs formed in a specific region of the solar system and were, after their formation, not homogeneously redistributed within the solar system. Combining the CAI data with improved model predictions for early solar system irradiation effects indicates that a local production scenario for the relatively short lived radionuclides can be excluded, because the production of, e.g., {sup 10}Be, {sup 26}Al, and {sup 41}Ca, would result in a significant collateral shift in Ti isotopes, which is not seen in the measured data.

Leya, Ingo [Physical Institute, Space Sciences and Planetology, University of Bern (Switzerland); Schoenbaechler, Maria [School of Earth, Atmospheric and Environmental Sciences, University of Manchester (United Kingdom); Kraehenbuehl, Urs [Laboratory for Radiochemistry, University of Bern (Switzerland); Halliday, Alex N. [Deparment of Earth Sciences, University of Oxford, Oxford (United Kingdom)], E-mail: Ingo.Leya@space.unibe.ch

2009-09-10T23:59:59.000Z

336

Process for hydrogen isotope concentration between liquid water and hydrogen gas  

DOE Patents (OSTI)

A process for hydrogen isotope exchange and concentration between liquid water and hydrogen gas, wherein liquid water and hydrogen gas are contacted, in an exchange section, with one another and with at least one catalyst body comprising at least one metal selected from Group VIII of the Periodic Table and preferably a support therefor, the catalyst body has a liquid-water-repellent, gas permeable polymer or organic resin coating, preferably a fluorinated olefin polymer or silicone coating, so that the isotope concentration takes place by two simultaneously occurring steps, namely, ##EQU1## WHILE THE HYDROGEN GAS FED TO THE EXCHANGE SECTION IS DERIVED IN A REACTOR VESSEL FROM LIQUID WATER THAT HAS PASSED THROUGH THE EXCHANGE SECTION.

Stevens, William H. (Deep River, CA)

1976-09-21T23:59:59.000Z

337

Higgs Mass Calculations  

NLE Websites -- All DOE Office Websites (Extended Search)

this sheet now. Help with data analysis Higgs Mass Plot Project Contact: Thomas Jordan - jordant@fnal.gov Web Maintainer: qnet-webmaster@fnal.gov Last Update: August 22,...

338

Solids mass flow determination  

DOE Patents (OSTI)

Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.

Macko, Joseph E. (Hempfield Township, Westmoreland County, PA)

1981-01-01T23:59:59.000Z

339

Physics with Rare Isotope Beams  

Science Conference Proceedings (OSTI)

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.

Segel, Ralph E. [Northwestern University

2013-11-08T23:59:59.000Z

340

W Transverse Mass  

NLE Websites -- All DOE Office Websites (Extended Search)

Transverse Mass Histogram Transverse Mass Histogram Data for 49,844 candidate W events are in an Excel spreadsheet with the following data as shown in the table below: A B C D 1 Run No Event No W TMass GeV/c2 Bins 2 55237 19588 68.71732 3 55237 30799 72.19464 Get the data. Sort the data by ascending mass. Be sure to sort all the data in the first three columns! Make a histogram of the data. Rather than graphing the data as individual points, physicists group the data by mass. They consider the full range of the data and divide it into "bins" of equal range size. A histogram is a graph of the number of events in each bin vs. the bin range. They are looking for a peak in the data where most of the masses fall. This will be the value of the mass as detemined by that dataset, and the width of the distribution is a reflection of the errors in the measurements.

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

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

SciTech Connect

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.

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

2013-04-21T23:59:59.000Z

342

Middle-Late Permian mass extinction on land  

Science Conference Proceedings (OSTI)

The end-Permian mass extinction has been envisaged as the nadir of biodiversity decline due to increasing volcanic gas emissions over some 9 million years. We propose a different tempo and mechanism of extinction because we recognize two separate but geologically abrupt mass extinctions on land, one terminating the Middle Permian (Guadalupian) at 260.4 Ma and a later one ending the Permian Period at 251 Ma. Our evidence comes from new paleobotanical, paleopedological, and carbon isotopic studies of Portal Mountain, Antarctica, and comparable studies in the Karoo Basin, South Africa. Extinctions have long been apparent among marine invertebrates at both the end of the Guadalupian and end of the Permian, which were also times of warm-wet greenhouse climatic transients, marked soil erosion, transition from high- to low-sinuosity and braided streams, soil stagnation in wetlands, and profound negative carbon isotope anomalies. Both mass extinctions may have resulted from catastrophic methane outbursts to the atmosphere from coal intruded by feeder dikes to flood basalts, such as the end-Guadalupian Emeishan Basalt and end-Permian Siberian Traps.

Retallack, G.J.; Metzger, C.A.; Greaver, T.; Jahren, A.H.; Smith, R.M.H.; Sheldon, N.D. [University of Oregon, Eugene, OR (United States). Dept. of Geological Science

2006-11-15T23:59:59.000Z

343

Isotopic Analysis At Dixie Valley Geothermal Field Area (Laney, 2005) |  

Open Energy Info (EERE)

Isotopic Analysis At Dixie Valley Geothermal Field Area (Laney, 2005) Isotopic Analysis At Dixie Valley Geothermal Field Area (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Dixie Valley Geothermal Field Area (Laney, 2005) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness not indicated DOE-funding Unknown Notes Gas and Isotopes Geochemistry, Kennedy, van Soest and Shevenell. During FY04, we concentrated on two primary projects. The first was a detailed study of helium isotope systematics throughout Dixie Valley and the inter-relationship between the Dixie Valley geothermal reservoir and local hydrology. The second is the construction of a helium isotope "map" of the

344

Method of preparing mercury with an arbitrary isotopic distribution  

DOE Patents (OSTI)

This invention provides for a process for preparing mercury with a predetermined, arbitrary, isotopic distribution. In one embodiment, different isotopic types of Hg[sub 2]Cl[sub 2], corresponding to the predetermined isotopic distribution of Hg desired, are placed in an electrolyte solution of HCl and H[sub 2]O. The resulting mercurous ions are then electrolytically plated onto a cathode wire producing mercury containing the predetermined isotopic distribution. In a similar fashion, Hg with a predetermined isotopic distribution is obtained from different isotopic types of HgO. In this embodiment, the HgO is dissolved in an electrolytic solution of glacial acetic acid and H[sub 2]O. The isotopic specific Hg is then electrolytically plated onto a cathode and then recovered. 1 fig.

Grossman, M.W.; George, W.A.

1986-12-16T23:59:59.000Z

345

Method of preparing mercury with an arbitrary isotopic distribution  

DOE Patents (OSTI)

This invention provides for a process for preparing mercury with a predetermined, arbitrary, isotopic distribution. In one embodiment, different isotopic types of Hg.sub.2 Cl.sub.2, corresponding to the predetermined isotopic distribution of Hg desired, are placed in an electrolyte solution of HCl and H.sub.2 O. The resulting mercurous ions are then electrolytically plated onto a cathode wire producing mercury containing the predetermined isotopic distribution. In a similar fashion, Hg with a predetermined isotopic distribution is obtained from different isotopic types of HgO. In this embodiment, the HgO is dissolved in an electrolytic solution of glacial acetic acid and H.sub.2 O. The isotopic specific Hg is then electrolytically plated onto a cathode and then recovered.

Grossman, Mark W. (Belmont, MA); George, William A. (Rockport, MA)

1986-01-01T23:59:59.000Z

346

Secondary Ion Mass Spectrometry of Environmental Aerosols  

Science Conference Proceedings (OSTI)

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.

Gaspar, Daniel J.; Cliff, John B.

2010-08-01T23:59:59.000Z

347

Fission Yield Measurements by Inductively Coupled Plasma Mass-Spectrometry  

SciTech Connect

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.

Irina Glagolenko; Bruce Hilton; Jeffrey Giglio; Daniel Cummings; Karl Grimm; Richard McKnight

2009-11-01T23:59:59.000Z

348

Giga-Dalton Mass Spectrometry  

Current techniques to study large bio?molecules using mass spectrometer require fragmentation for the mass?to?charge ratios to be within the working range of the mass spectrometer. Analysis of the data is complex and often requires simulation ...

349

Measuring the Effect of Fuel Chemical Structure on Particulate and Gaseous Emissions using Isotope Tracing  

DOE Green Energy (OSTI)

Using accelerator mass spectrometry (AMS), a technique initially developed for radiocarbon dating and recently applied to internal combustion engines, carbon atoms within specific fuel molecules can be labeled and followed in particulate or gaseous emissions. In addition to examining the effect of fuel chemical structure on emissions, the specific source of carbon for PM can be identified if an isotope label exists in the appropriate fuel source. Existing work has focused on diesel engines, but the samples (soot collected on quartz filters or combustion gases captured in bombs or bags) are readily collected from large industrial combustors as well.

Buchholz, B A; Mueller, C J; Martin, G C; Upatnicks, A; Dibble, R W; Cheng, S

2003-09-11T23:59:59.000Z

350

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

E-Print Network (OSTI)

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.

Sarriguren, P

2010-01-01T23:59:59.000Z

351

Isotope effects in the harmonic response from hydrogenlike muonic atoms in strong laser fields  

SciTech Connect

High-order harmonic generation from hydrogenlike muonic atoms exposed to ultraintense high-frequency laser fields is studied. Systems of low nuclear-charge number Z are considered where a nonrelativistic description applies. By comparing the radiative response for different isotopes, we demonstrate characteristic signatures of the finite nuclear mass and size in the harmonic spectra. In particular, for Z>1, an effective muon charge appears in the Schroedinger equation for the relative particle motion, which influences the position of the harmonic cutoff. Cutoff energies in the million-electron-volt domain can be achieved, offering prospects for the generation of ultrashort coherent {gamma}-ray pulses.

Shahbaz, Atif; Mueller, Carsten [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Buervenich, Thomas J. [Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Ruth-Moufang-Strasse 1, D-60438 Frankfurt am Main (Germany)

2010-07-15T23:59:59.000Z

352

Predictability of an Atmospheric Blocking Event that Occurred on 15 December 2005  

Science Conference Proceedings (OSTI)

Atmospheric blocking occurred over the Rocky Mountains at 1200 UTC 15 December 2005. The operational medium-range ensemble forecasts of the Canadian Meteorological Center (CMC), the Japan Meteorological Agency (JMA), and the National Centers for ...

Mio Matsueda; Masayuki Kyouda; Zoltan Toth; H. L. Tanaka; Tadashi Tsuyuki

2011-08-01T23:59:59.000Z

353

ISOTOPIC RATIOS IN TITAN's METHANE: MEASUREMENTS AND MODELING  

SciTech Connect

The existence of methane in Titan's atmosphere ({approx}6% level at the surface) presents a unique enigma, as photochemical models predict that the current inventory will be entirely depleted by photochemistry in a timescale of {approx}20 Myr. In this paper, we examine the clues available from isotopic ratios ({sup 12}C/{sup 13}C and D/H) in Titan's methane as to the past atmosphere history of this species. We first analyze recent infrared spectra of CH{sub 4} collected by the Cassini Composite Infrared Spectrometer, measuring simultaneously for the first time the abundances of all three detected minor isotopologues: {sup 13}CH{sub 4}, {sup 12}CH{sub 3}D, and {sup 13}CH{sub 3}D. From these we compute estimates of {sup 12}C/{sup 13}C = 86.5 {+-} 8.2 and D/H = (1.59 {+-} 0.33) Multiplication-Sign 10{sup -4}, in agreement with recent results from the Huygens GCMS and Cassini INMS instruments. We also use the transition state theory to estimate the fractionation that occurs in carbon and hydrogen during a critical reaction that plays a key role in the chemical depletion of Titan's methane: CH{sub 4} + C{sub 2}H {yields} CH{sub 3} + C{sub 2}H{sub 2}. Using these new measurements and predictions we proceed to model the time evolution of {sup 12}C/{sup 13}C and D/H in Titan's methane under several prototypical replenishment scenarios. In our Model 1 (no resupply of CH{sub 4}), we find that the present-day {sup 12}C/{sup 13}C implies that the CH{sub 4} entered the atmosphere 60-1600 Myr ago if methane is depleted by chemistry and photolysis alone, but much more recently-most likely less than 10 Myr ago-if hydrodynamic escape is also occurring. On the other hand, if methane has been continuously supplied at the replenishment rate then the isotopic ratios provide no constraints, and likewise for the case where atmospheric methane is increasing. We conclude by discussing how these findings may be combined with other evidence to constrain the overall history of the atmospheric methane.

Nixon, C. A.; Achterberg, R. K. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Temelso, B. [Dean's Office, College of Arts and Sciences, Department of Chemistry, Bucknell University, Lewisburg, PA 17837 (United States); Vinatier, S.; Bezard, B.; Coustenis, A. [LESIA, Observatoire de Paris, CNRS, 5 Place Jules Janssen, 92195 Meudon Cedex (France); Teanby, N. A. [School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ (United Kingdom); Mandt, K. E. [Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228 (United States); Sherrill, C. D. [School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332-0400 (United States); Irwin, P. G. J. [Atmospheric, Oceanic and Planetary Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom); Jennings, D. E.; Romani, P. N.; Flasar, F. M. [Planetary Systems Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-04-20T23:59:59.000Z

354

Descriptions of selected accidents that have occurred at nuclear reactor facilities  

SciTech Connect

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.

Bertini, H.W.

1980-04-01T23:59:59.000Z

355

Descriptions of selected accidents that have occurred at nuclear reactor facilities  

SciTech Connect

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.

Bertini, H.W.

1980-04-01T23:59:59.000Z

356

EMSL: Capabilities: Mass Spectrometry Experts  

NLE Websites -- All DOE Office Websites (Extended Search)

Related EMSL User Projects Mass Spectrometry Tools are Applied to all Science Themes Next-Generation Mass Spectrometry Proteomics Research Resource for Integrative Biology...

357

Photon: history, mass, charge  

E-Print Network (OSTI)

The talk consists of three parts. ``History'' briefly describes the emergence and evolution of the concept of photon during the first two decades of the 20th century. ``Mass'' gives a short review of the literature on the upper limit of the photon's mass. ``Charge'' is a critical discussion of the existing interpretation of searches for photon charge. Schemes, in which all photons are charged, are grossly inconsistent. A model with three kinds of photons (positive, negative and neutral) seems at first sight to be more consistent, but turns out to have its own serious problems.

L. B. Okun

2006-02-03T23:59:59.000Z

358

Mass and Heat Recovery  

E-Print Network (OSTI)

In the last few years heat recovery was under spot and in air conditioning fields usually we use heat recovery by different types of heat exchangers. The heat exchanging between the exhaust air from the building with the fresh air to the building (air to air heat exchanger). In my papers I use (water to air heat exchanger) 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.

Hindawai, S. M.

2010-01-01T23:59:59.000Z

359

Diffusional exchange of isotopes in a metal hydride sphere.  

DOE Green Energy (OSTI)

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.

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

2011-04-01T23:59:59.000Z

360

Optically pumped isotopic ammonia laser system  

DOE Patents (OSTI)

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.

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

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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361

Hydrogen isotope separation utilizing bulk getters  

DOE Patents (OSTI)

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.

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

1991-01-01T23:59:59.000Z

362

Hydrogen isotope separation utilizing bulk getters  

DOE Patents (OSTI)

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.

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

1990-01-01T23:59:59.000Z

363

Hydrogen isotope separation utilizing bulk getters  

DOE Patents (OSTI)

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.

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

1991-08-20T23:59:59.000Z

364

A METHODOLOGY FOR DETERMINING THE DOSE RATE FOR BOUNDING MASS LIMITS IN A 9977 PACKAGING  

SciTech Connect

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.

Abramczyk, G.; Bellamy, S.; Nathan, S.; Loftin, B.

2012-05-24T23:59:59.000Z

365

Low-energy Coulomb excitation of neutron-rich zinc isotopes  

E-Print Network (OSTI)

At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,20) values in 74-80Zn, B(E2,42) values in 74,76Zn and the determination of the energy of the first excited 2 states in 78,80Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of 238U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, i...

Van de Walle, J; Behrens, T; Bildstein, V; Blazhev, A; Cederkäll, J; Clément, E; Cocolios, T E; Davinson, T; Delahaye, P; Eberth, J; Ekström, A; Fedorov, D V; Fedosseev, V; Fraile, L M; Franchoo, S; Gernhäuser, R; Georgiev, G; Habs, D; Heyde, K; Huber, G; Huyse, M; Ibrahim, F; Ivanov, O; Iwanicki, J; Jolie, J; Kester, O; Köster, U; Kröll, T; Krücken, R; Lauer, M; Lisetskiy, A F; Lutter, R; Marsh, B A; Mayet, P; Niedermaier, O; Pantea, M; Raabe, R; Reiter, P; Sawicka, M; Scheit, H; Schrieder, G; Schwalm, D; Seliverstov, M D; Sieber, T; Sletten, G; Smirnova, N; Stanoiu, M; Stefanescu, I; Thomas, J C; Valiente-Dobón, J J; Van Duppen, P; Verney, D; Voulot, D; Warr, N; Weisshaar, D; Wenander, F; Wolf, B H; Zielinska, M

2009-01-01T23:59:59.000Z

366

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network (OSTI)

Pakistan is exacerbated by concerns over both terrorist activity and the security of its rapidly increasing nuclear

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

367

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network (OSTI)

Attribution and Non-Proliferation Applications”, IEEETreaty on the Non-Proliferation of Nuclear Weapons (NPT)”,as detailed in the Non-Proliferation Treaty (NPT), is to

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

368

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network (OSTI)

Proliferation of Nuclear Weapons (NPT)”, http: //www.un.org/end of the Cold War, nuclear weapons remain at the heart ofthe spread of nuclear weapons, analysis of nuclear materials

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

369

A Mass Spectrometry Study of Isotope Separation in the Laser Plume  

E-Print Network (OSTI)

as detailed in the Non-Proliferation Treaty (NPT), is toUnited Nations, “Treaty on the Non-Proliferation of Nuclear

Suen, Timothy Wu

2012-01-01T23:59:59.000Z

370

Massive sulfide deposits and hydrothermal solutions: incremental reaction modeling of mineral precipitation and sulfur isotopic evolution  

DOE Green Energy (OSTI)

Incremental reaction path modeling of chemical and sulfur isotopic reactions occurring in active hydrothermal vents on the seafloor, in combination with chemical and petrographic data from sulfide samples from the seafloor and massive sulfide ore deposits, allows a detailed examination of the processes involved. This paper presents theoretical models of reactions of two types: (1) adiabatic mixing between hydrothermal solution and seawater, and (2) reaction of hydrothermal solution with sulfide deposit materials. In addition, reaction of hydrothermal solution with sulfide deposit minerals and basalt in feeder zones is discussed.

Janecky, D.R.

1986-01-01T23:59:59.000Z

371

Isotope effect on adsorbed quantum phases: Diffusion of H2 and D2 in nanoporous carbon  

SciTech Connect

Quasielastic neutron scattering of H2 and D2 in a nanoporous carbon at 10 40 K demonstrates extreme quantum sieving, with D2 diffusing up to 76 times faster. D2 also shows liquid-like diffusion, while H2 exhibits distinct solid-type diffusion. The onset of diffusion occurs at 22 25 K for H2 and 10 13 K for D2. We show this difference may be explained by different commensurability of the two adsorbed isotopes with carbon substrate. We further observe that H2 and D2 have identical thermal de Broglie wavelength at their respective onset temperatures, and correlated with the dominant pore size.

Contescu, Cristian I [ORNL; Zhang, Hongxin [ORNL; Olsen, Raina J [ORNL; Mamontov, Eugene [ORNL; Morris, James R [ORNL; Gallego, Nidia C [ORNL

2013-01-01T23:59:59.000Z

372

Warm Water Mass Formation  

Science Conference Proceedings (OSTI)

Poleward heat transport by the own implies warm Water mass formation, i.e., the retention by the tropical and subtropical ocean of some of its net radiant heat gain. Under what condition net heat retention becomes comparable to latent heat ...

G. T. Csanady

1984-02-01T23:59:59.000Z

373

Provenance analysis of Olivella biplicata shell beads from the California and Oregon Coast by stable isotope fingerprinting  

E-Print Network (OSTI)

isotope composition of planktonic foraminifera, Geology 27 (isotope fractionation in biogenic aragonite: Temperature effects, Chemical GeologyIsotope paleontology: growth and composition of extant calcareous species, Marine Geology

Eerkens, J W; Herbert, G S; Rosenthal, J S; Spero, H J

2005-01-01T23:59:59.000Z

374

Isotopic Analysis- Fluid At Sierra Valley Geothermal Area (1990) | Open  

Open Energy Info (EERE)

Isotopic Analysis- Fluid At Sierra Valley Geothermal Area (1990) Isotopic Analysis- Fluid At Sierra Valley Geothermal Area (1990) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Sierra Valley Geothermal Area (1990) Exploration Activity Details Location Sierra Valley Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date 1990 Usefulness not indicated DOE-funding Unknown Exploration Basis Determine the recharge of the area Notes Hydrogen and oxygen isotope data on waters of Coso thermal and nonthermal waters were studied. Hydrogen and oxygen isotopes do not uniquely define the recharge area for the Coso geothermal system but strongly suggest Sierran recharge with perhaps some local recharge. References Whelan, J. A. (1 September 1990) Water geochemistry study of

375

Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal Area  

Open Energy Info (EERE)

Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal Area Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal Area (1990) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal Area (1990) Exploration Activity Details Location Indian Valley Hot Springs Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date 1990 Usefulness not indicated DOE-funding Unknown Exploration Basis Determine the recharge of the area Notes Hydrogen and oxygen isotope data on waters of Coso thermal and nonthermal waters were studied. Hydrogen and oxygen isotopes do not uniquely define the recharge area for the Coso geothermal system but strongly suggest Sierran recharge with perhaps some local recharge. References

376

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Engineering - Oak Ridge National Laboratory High Flux Isotope Engineering - 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 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2007 assessment of the Engineering Program in preparation for restart of the Oak Ridge National Laboratory High Flux Isotope Reactor. CRADs provide a recommended approach and the types of information to gather to assess elements of a DOE contractor's programs. CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor More Documents & Publications CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor

377

Isotope Development & Production for Research and Applications (IDPRA) |  

NLE Websites -- All DOE Office Websites (Extended Search)

Research » Isotope Research » Isotope Development & Production for Research and Applications (IDPRA) Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Research Isotope Development & Production for Research and Applications (IDPRA) Print Text Size: A A A RSS Feeds FeedbackShare Page 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

378

Isotope Geochemistry Of Minerals And Fluids From Newberry Volcano, Oregon |  

Open Energy Info (EERE)

Isotope Geochemistry Of Minerals And Fluids From Newberry Volcano, Oregon Isotope Geochemistry Of Minerals And Fluids From Newberry Volcano, Oregon Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Isotope Geochemistry Of Minerals And Fluids From Newberry Volcano, Oregon Details Activities (2) Areas (1) Regions (0) Abstract: Isotopic compositions were determined for hydrothermal quartz, calcite, and siderite from core samples of the Newberry 2 drill hole, Oregon. The Δ15O values for these minerals decrease with increasing temperatures. The values indicate that these hydrothermal minerals precipitated in isotopic equilibrium with water currently present in the reservoirs. The Δ18O values of quartz and calcite from the andesite and basalt flows (700-932 m) have isotopic values which require that the equilibrated water Δ18O values increase slightly (- 11.3 to -9.2‰) with

379

Isotopic Analysis- Fluid At Rose Valley Geothermal Area (1990) | Open  

Open Energy Info (EERE)

Isotopic Analysis- Fluid At Rose Valley Geothermal Area (1990) Isotopic Analysis- Fluid At Rose Valley Geothermal Area (1990) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Rose Valley Geothermal Area (1990) Exploration Activity Details Location Rose Valley Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date 1990 Usefulness not indicated DOE-funding Unknown Exploration Basis Determine the recharge of the area Notes Hydrogen and oxygen isotope data on waters of Coso thermal and nonthermal waters were studied. Hydrogen and oxygen isotopes do not uniquely define the recharge area for the Coso geothermal system but strongly suggest Sierran recharge with perhaps some local recharge. References Whelan, J. A. (1 September 1990) Water geochemistry study of

380

Plutonium isotopic analysis of highly enriched mixed oxides  

SciTech Connect

We investigated the analysis method used by the International Atomic Energy Agency (IAEA) to determine the plutonium isotopic composition of highly enriched mixed oxides (MOX). The IAEA currently uses the Cicero multichannel analyzer and the IAEAPU algorithm for its analysis. In our investigation the plutonium isotopic measurements were found to be good for PuO/sub 2/ powder or low-enriched MOX, but acceptable for highly enriched MOX in IAEA special nuclear material (SNM) accountability applications. The gamma-ray interferences from /sup 235/U resulted in underestimation of the isotopic composition of /sup 239/Pu and overestimation of all other plutonium isotopes. Samples with high /sup 240/Pu content were found to have significantly higher error in plutonium isotopic analyses of highly enriched MOX. Code modifications or use of calibration curves are necessary for plutonium isotopic analyses of highly enriched MOX in IAEA SNM accountability applications.

Clement, S.D.; Augustson, R.H.

1986-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

CRAD, Management- Oak Ridge National Laboratory High Flux Isotope Reactor |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Management- Oak Ridge National Laboratory High Flux Isotope Management- Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Management- Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2007 assessment of the Management in preparation for restart of the Oak Ridge National Laboratory High Flux Isotope Reactor. CRADs provide a recommended approach and the types of information to gather to assess elements of a DOE contractor's programs. CRAD, Management- Oak Ridge National Laboratory High Flux Isotope Reactor More Documents & Publications CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope

382

Method for calibrating mass spectrometers  

DOE Patents (OSTI)

A method whereby a mass spectra generated by a mass spectrometer is calibrated by shifting the parameters used by the spectrometer to assign masses to the spectra in a manner which reconciles the signal of ions within the spectra having equal mass but differing charge states, or by reconciling ions having known differences in mass to relative values consistent with those known differences. In this manner, the mass spectrometer is calibrated without the need for standards while allowing the generation of a highly accurate mass spectra by the instrument.

Anderson, Gordon A [Benton City, WA; Brands, Michael D [Richland, WA; Bruce, James E [Schwenksville, PA; Pasa-Tolic, Ljiljana [Richland, WA; Smith, Richard D [Richland, WA

2002-12-24T23:59:59.000Z

383

USE OF NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE  

Open Energy Info (EERE)

NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE COSO EGS PROJECT Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: USE OF NATURALLY-OCCURRING TRACERS TO MONITOR TWO-PHASE CONDITIONS IN THE COSO EGS PROJECT Details Activities (1) Areas (1) Regions (0) Abstract: A dramatic decrease in the ratio of chloride to boron was observed in the liquid discharge of a well proposed for EGS development in the Coso geothermal field. The decrease appears to be related to the transformation of some feed zones in the well from liquid-dominated to vapor-dominated. High concentrations of boron are transported to the wellbore in the steam, where it fractionates to the liquid phase flowing in from liquid-dominated feed zones. The high-boron steam is created when the

384

Chromatographic Measurement of Isotopic Hydrogen Impurities in Purified Tritium  

SciTech Connect

A cryogenic gas chromatograph is described that was constructed for dedicated analysis of permanent gas and hydrogen isotopic impurities in tritium and deuterium-tritium mixtures. The operating characteristics of this instrument and some results are presented in order to introduce gas chromatography as an analytical technique for potential application to CTR technology situations that require accurate measurement of parts per million and higher levels of isotopic and permanent gas impurities in tritium, deuterium, or mixtures of the isotopes.

Warner, D. K.; Kinard, C.; Bohl, D. R.

1970-09-21T23:59:59.000Z

385

System and method for high precision isotope ratio destructive analysis  

DOE Patents (OSTI)

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).

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

2013-07-02T23:59:59.000Z

386

Twisted mass finite volume effects  

SciTech Connect

We calculate finite-volume effects on the pion masses and decay constant in twisted mass lattice QCD at finite lattice spacing. We show that the lighter neutral pion in twisted mass lattice QCD gives rise to finite-volume effects that are exponentially enhanced when compared to those arising from the heavier charged pions. We demonstrate that the recent two flavor twisted mass lattice data can be better fitted when twisted mass effects in finite-volume corrections are taken into account.

Colangelo, Gilberto; Wenger, Urs; Wu, Jackson M. S. [Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, University of Bern, Sidlerstrasse 5, 3012 Bern (Switzerland)

2010-08-01T23:59:59.000Z

387

A post accelerator for the U.S. rare isotope accelerator facility.  

Science Conference Proceedings (OSTI)

Work supported by the U. S. Department of Energy under contract W-31-109-ENG-38. The proposed Rare Isotope Accelerator (RIA) Facility includes a post-accelerator for rare isotopes (RIB linac) which must produce high-quality beams of radioactive ions over the full mass range, including uranium, at energies above the coulomb barrier, and have high transmission and efficiency. The latter requires the RIB linac to accept at injection ions in the 1+ charge state. A concept for such a post accelerator suitable for ions up to mass 132 has been previously described [1]. This paper presents a modified concept which extends the mass range to uranium. A high resolution separator for purifying beams at the isobaric level precedes the RIB linac. The mass filtering process will provide high purity beams while preserving transmission. For most cases a resolution of about m/{Delta}m=20,000 is adequate at mass A=100 to obtain a separation between isobars of mass excess difference of 5 MeV. The design for a device capable of purifying beams at the isobaric level included calculations up to 5th order. The RIB linac will utilize existing superconducting heavy-ion linac technology for all but a small portion of the accelerator system. The exceptional piece, a very-low-charge-state injector, section needed for just the first few MV of the RIB accelerator, consists of a pre-buncher followed by several sections of cw, normally-conducting RFQ. Two stages of charge stripping are provided: helium gas stripping at energies of a few keV/u, and additional foil stripping at {approx}680 keV/u for the heavier ions. In extending the mass range to uranium, however, for best efficiency the helium gas stripping must be performed at different energies for different mass ions. We present numerical simulations of the beam dynamics of a design for the complete RIB linac which provides for several stripping options and uses cost-effective solenoid focusing elements in the drift-tube linac.

Ostroumov, P. N.; Kelly, M. P.; Kolomiets, A. A.; Nolen, J. A.; Portillo, M.; Shepard, K. W.; Vinogradov, N. E.

2002-06-11T23:59:59.000Z

388

Validation of a Monte Carlo based depletion methodology via High Flux Isotope Reactor HEU post-irradiation examination measurements  

Science Conference Proceedings (OSTI)

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.

Chandler, David [ORNL; Maldonado, G Ivan [ORNL; Primm, Trent [ORNL

2010-01-01T23:59:59.000Z

389

Oxygen Isotope Evidence For Past And Present Hydrothermal Regimes...  

Open Energy Info (EERE)

oxygen isotope compositions of cores and cuttings from Long Valley exploration wells show that the Bishop Tuff has been an important reservoir for both fossil and active...

390

Stable Isotope Enrichment by Thermal Diffusion, Chemical Exchange, and Distillation  

SciTech Connect

Applications of stable isotopes in medicine are becoming more widespread. This has resulted from the increased availability and reduced cost of these isotopes and the improved reliability and sensitivity of detection techniques such as carbon-13 nuclear magnetic resonance. Isotopes are used in compounds labeled with either the stable isotope itself, such as carbon-13 and oxygen-18, or with the radioactive isotope that can be produced by irradiating the stable isotope, such as the irradiation of xenon-124 to produce iodine-125. As the demand for stable isotopes increases, larger scale production facilities will be justifiable. The increased size of production facilities should result in yet lower unit selling prices. A large number of methods has been suggested for the separation of stable isotopes. This paper concerns itself with four methods which have proven extremely useful for the separation of the isotopes of low and medium atomic weight elements. The four processes discussed are gas phase thermal diffusion, liquid phase thermal diffusion, chemical exchange, and distillation.

Schwind, Dr. Roger A.; Rutherford, Dr. William M.

1973-03-01T23:59:59.000Z

391

Isotopic Analysis At Dixie Valley Geothermal Field Area (Kennedy...  

Open Energy Info (EERE)

system. References B. Mack Kennedy, Matthijs C. van Soest (2005) Regional And Local Trends In Helium Isotopes, Basin And Range Province, Western North America- Evidence For Deep...

392

A Strontium Isotopic Study Of Newberry Volcano, Central Oregon...  

Open Energy Info (EERE)

Strontium Isotopic Study Of Newberry Volcano, Central Oregon- Structural And Thermal Implications Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A...

393

Isotopic Analysis At Newberry Caldera Area (Goles & Lambert,...  

Open Energy Info (EERE)

References Gordon G. Goles, Richard St J. Lambert (1990) A Strontium Isotopic Study Of Newberry Volcano, Central Oregon- Structural And Thermal Implications Retrieved from...

394

John De Laeter Centre For Isotope Research | Open Energy Information  

Open Energy Info (EERE)

2013 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for John De Laeter Centre For Isotope Research Citation Curtin University. John...

395

Isotopic Analysis At Northern Basin & Range Region (Cole, 1983...  

Open Energy Info (EERE)

Date Usefulness not indicated DOE-funding Unknown References David R. Cole (1983) Chemical And Isotopic Investigation Of Warm Springs Associated With Normal Faults In Utah...

396

Chemical and isotopic characteristics of the coso east flank...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Chemical and isotopic characteristics of the coso east flank hydrothermal fluids: implications...

397

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...

398

Report of Survey of Oak Ridge Isotope Enrichment (Calutron) Facility...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Power Marketing Administration Other Agencies You are here Home Report of Survey of Oak Ridge Isotope Enrichment (Calutron) Facility Building 9204-3 Report of Survey of Oak...

399

Small-Scale Reactor for the Production of Medical Isotopes ...  

Currently, there is a severe worldwide shortage of medical isotopes-specifically Molybdenum 99 (Mo-99) which is essential in cancer treatment, ...

400

Isotopic Analysis At Dixie Valley Geothermal Field Area (Kennedy...  

Open Energy Info (EERE)

| Sign Up Search Page Edit History Facebook icon Twitter icon Isotopic Analysis At Dixie Valley Geothermal Field Area (Kennedy & Van Soest, 2006) Jump to: navigation, search...

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Regional And Local Trends In Helium Isotopes, Basin And Range...  

Open Energy Info (EERE)

Superimposed on this general regional trend are isolated features with elevated helium isotope ratios (0.8-2.1 Ra) compared to the local background. Spring geochemistry and...

402

Gas Chromatographic Separation of Hydrogen Isotopes on Molecular Sieves  

Science Conference Proceedings (OSTI)

Tritium Processing / Proceedings of the Third Topical Meeting on Tritium Technology in Fission, Fusion and Isotopic Applications (Toronto, Ontario, Canada, May 1-6, 1988)

R. Vogd; H. Ringel; H. Hackfort; T. Schober; C. Dieker

403

Small-Scale Reactor for the Production of Medical Isotopes  

Small-Scale Reactor for the Production of Medical Isotopes IP Home; Search/Browse Technology ... Drawing upon proven technology with minimal research effort required;

404

Lead and strontium isotopic evidence for crustal interaction...  

Open Energy Info (EERE)

Mineralogy and Petrology, 111984 Document Number: Unavailable DOI: 10.1007BF01150293 Source: View Original Conference Proceedings Isotopic Analysis- Rock At Coso Geothermal...

405

Evolution of massive stars losing mass and angular momentum supergiants  

SciTech Connect

Evolutionary sequences have been computed to central helium exhaustion for massive Population I star models with initial masses of 40, 60, 80, and 100 M/sub sun/. Mass loss occurs through radiatively driven winds and through the effects of nonthermal winds generated both by rotational shear turbulence during the mainsequence (MS) phase and by the acoustic energy flux from the convective envelope during the red supergiant phase. The size of the convective envelope in the red supergiant phase is found to depend on the mass loss history of the star, through the effect of mass loss on the position of the hydrogen shell source (HSS) and on the opacity of the envelope above the HSS. Previous evolutionary calculations have shown that, for low mass loss rates, a blue loop forms when the HSS contacts the discontinuity at the base of the convective envelope. In contrast, the higher mass loss rates considered here produce a blue loop only if sufficient mass loss occurs during the red supergiant phase to eliminate the convective envelope entirely. On the other hand, sufficiently high mass loss rates during the MS phase can remove most of the hydrogen-rich envelope, and then the red supergiant phase does not occur. In these models the mass loss and evolutionary patterns for a star depend on its initial rotational speed, which in actual stars is expected to vary from star to star. The observed blue-to-red supergiant ratios are then interpreted as weighted means of different evolutionary patterns resulting from a spread of initial rotational speeds. The same interpretation may extend to Wolf-Rayet stars.

Sreenivasan, S.R.; Wilson, W.J.F.

1985-03-15T23:59:59.000Z

406

Penning trap mass measurements on (99-109)$Cd with ISOLTRAP and implications on the rp process  

E-Print Network (OSTI)

Penning trap mass measurements on neutron-deficient Cd isotopes (99-109)Cd have been performed with the ISOLTRAP mass spectrometer at ISOLDE/CERN, all with relative mass uncertainties below 3*10^8. A new mass evaluation has been performed. The mass of 99Cd has been determined for the first time which extends the region of accurately known mass values towards the doubly magic nucleus 100Sn. The implication of the results on the reaction path of the rp process in stellar X-ray bursts is discussed. In particular, the uncertainty of the abundance and the overproduction created by the rp-process for the mass A = 99 is demonstrated by reducing the uncertainty of the proton-separation energy of 100In Sp(100In) by a factor of 2.5.

M. Breitenfeldt; G. Audi; D. Beck; K. Blaum; S. George; F. Herfurth; A. Herlert; A. Kellerbauer; H. -J. Kluge; M. Kowalska; D. Lunney; S. Naimi; D. Neidherr; H. Schatz; S. Schwarz; L. Schweikhard

2009-08-18T23:59:59.000Z

407

Mass Market Demand Response  

NLE Websites -- All DOE Office Websites (Extended Search)

Mass Market Demand Response Mass Market Demand Response Speaker(s): Karen Herter Date: July 24, 2002 - 12:00pm Location: Bldg. 90 Demand response programs are often quickly and poorly crafted in reaction to an energy crisis and disappear once the crisis subsides, ensuring that the electricity system will be unprepared when the next crisis hits. In this paper, we propose to eliminate the event-driven nature of demand response programs by considering demand responsiveness a component of the utility obligation to serve. As such, demand response can be required as a condition of service, and the offering of demand response rates becomes a requirement of utilities as an element of customer service. Using this foundation, we explore the costs and benefits of a smart thermostat-based demand response system capable of two types of programs: (1) a mandatory,

408

Single event mass spectrometry  

DOE Patents (OSTI)

A means and method for single event time of flight mass spectrometry for analysis of specimen materials. The method of the invention includes pulsing an ion source imposing at least one pulsed ion onto the specimen to produce a corresponding emission of at least one electrically charged particle. The emitted particle is then dissociated into a charged ion component and an uncharged neutral component. The ion and neutral components are then detected. The time of flight of the components are recorded and can be used to analyze the predecessor of the components, and therefore the specimen material. When more than one ion particle is emitted from the specimen per single ion impact, the single event time of flight mass spectrometer described here furnis This invention was made with Government support under Contract No. W-7405-ENG82 awarded by the Department of Energy. The Government has certain rights in the invention.

Conzemius, Robert J. (Ames, IA)

1990-01-16T23:59:59.000Z

409

Production of Intermediate-Mass and Heavy Nuclei  

SciTech Connect

Nucleosynthesis is the science related to all astrophysical processes which are responsible for the abundances of the elements and their isotopes in the universe. The astrophysical sites are the big bang and stellar objects. The working of nucleosynthesis processes is presented in a survey of events which act as abundance sources. For intermediate-mass and heavy elements, these are stellar evolution, type Ia and core collapse supernovae as well as hypernovae. We discuss successes and failures of existing processes and possible solutions via new (hitherto unknown) processes. Finally an analysis of their role is given in the puzzle to explain the evolution of the elemental and isotopic compositions found in galaxies, and especially the mixture found in the solar system. Different timescales due to the progenitor mass dependence of the endpoints of stellar evolution (type II supernova explosions - SNe II vs. planetary nebulae) or single vs. binary stellar systems (the latter being responsible for novae, type Ia supernovae -- SNe Ia, or X-ray bursts) are the keys to understand galactic evolution. At very early times, the role of explosion energies of events, polluting pristine matter with a composition originating only from the big bang, might also play a role. We also speculate on the role of very massive stars not undergoing SN II explosions but rather causing 'hypernovae' after the formation of a central black hole via core collapse.

Hix, William Raphael [ORNL; Thielemann, Friedrich-Karl W. [Universitat Basel, Switzerland; Fr?hlich, Dr. Carla [Universitat Basel, Switzerland; Hirschi, Raphael [Universitat Basel, Switzerland; Liebendoerfer, Matthias [Universitat Basel, Switzerland; Dillmann, Iris [Universitat Basel, Switzerland; Mocelj, Darko [Universitat Basel, Switzerland; Rauscher, Thomas [Universitat Basel, Switzerland; Martinez-Pinedo, Gabriel [Gesellschaft fur Schwerionenforschung (GSI), Germany; Langanke, Karlheinz [Gesellschaft fur Schwerionenforschung (GSI), Germany; Farouq, Khalil [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, Karl-Ludwig [ORNL; Pfeiffer, Bernard [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Panov, Igor V. [Alikhanov Institute for Theoretical and Experimental Physics, Moscow, Russia; Nadyozhin, Dimitri K [Alikhanov Institute for Theoretical and Experimental Physics, Moscow, Russia; Blinnikov, Sergei I [Alikhanov Institute for Theoretical and Experimental Physics, Moscow, Russia; Bravo, Eduardo [Universitat Politecnica de Catalunya, Barcelona, Spain; H?flich, Peter [Florida State University, Tallahassee; Zinner, Nikolaj T [ORNL

2007-07-01T23:59:59.000Z

410

The effect of a micro bubble dispersed gas phase on hydrogen isotope transport in liquid metals under nuclear irradiation  

E-Print Network (OSTI)

The present work intend to be a first step towards the understanding and quantification of the hydrogen isotope complex phenomena in liquid metals for nuclear technology. Liquid metals under nuclear irradiation in,e.g., breeding blankets of a nuclear fusion reactor would generate tritium which is to be extracted and recirculated as fuel. At the same time that tritium is bred, helium is also generated and may precipitate in the form of nano bubbles. Other liquid metal systems of a nuclear reactor involve hydrogen isotope absorption processes, e.g., tritium extraction system. Hence, hydrogen isotope absorption into gas bubbles modelling and control may have a capital importance regarding design, operation and safety. Here general models for hydrogen isotopes transport in liquid metal and absorption into gas phase, that do not depend on the mass transfer limiting regime, are exposed and implemented in OpenFOAMR CFD tool for 0D to 3D simulations. Results for a 0D case show the impact of a He dispersed phase of na...

Fradera, Jorge

2013-01-01T23:59:59.000Z

411

Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry  

Science Conference Proceedings (OSTI)

A preliminary radiological dose assessment related to equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials in production waste streams. The assessment evaluated the relative dose of these activities and included a sensitivity analysis of certain input parameters. Future studies and potential policy actions are recommended.

Smith, K.P.; Blunt, D.L.; Williams, G.P.; Tebes, C.L. [Argonne National Lab., IL (United States). Environmental Assessment Div.

1995-05-01T23:59:59.000Z

412

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

413

Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride  

E-Print Network (OSTI)

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...

American Society for Testing and Materials. Philadelphia

2011-01-01T23:59:59.000Z

414

Sensitive multi-photon nonlinear laser spectroscopic methods for isotope analysis in atmospheric and environmental applications  

E-Print Network (OSTI)

isotopic spectra of atomic chlorine with its two naturallythese applications. Figure 2.4 Chlorine isotope ratios inIsotope Measurements of Atomic Chlorine Using a Low-Pressure

Lyons, Wendy Jean

2009-01-01T23:59:59.000Z

415

Examining Wari influence in the Las Trancas Valley, Peru using oxygen isotopes from bone carbonate  

E-Print Network (OSTI)

Results. Chemical Geology (Isotope Geosciences Section),isotopes in fossil teeth from Pakistan. Chemical Geology,Isotope Composition of Human Tooth Enamel from Medieval Greenland: Linking Climate with Society: Comment. Geology,

Henry, Erin-Marie Lelik

2008-01-01T23:59:59.000Z

416

MULTIPLE SULFUR ISOTOPE FRACTIONATIONS IN BIOLOGICAL SYSTEMS: A CASE STUDY WITH SULFATE REDUCERS  

E-Print Network (OSTI)

MULTIPLE SULFUR ISOTOPE FRACTIONATIONS IN BIOLOGICAL SYSTEMS: A CASE STUDY WITH SULFATE REDUCERS*, DONALD E. CANFIELD**, and KIRSTEN S. HABICHT** ABSTRACT. Multiple sulfur isotope measurements of sulfur disproportionation indicate that different types of metabolic processes impart differ- ent multiple isotope

Kaufman, Alan Jay

417

Apparatus for isotopic alteration of mercury vapor  

DOE Patents (OSTI)

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.

Grossman, Mark W. (Belmont, MA); George, William A. (Gloucester, MA); Marcucci, Rudolph V. (Danvers, MA)

1988-01-01T23:59:59.000Z

418

Shell model description of zirconium isotopes  

Science Conference Proceedings (OSTI)

We calculate the low-lying spectra and several high-spin states of zirconium isotopes (Z=40) with neutron numbers from N=50 to N=58 using a large valence space with the {sup 78}Ni inert core, which a priori allows one to study the interplay between spherical and deformed configurations, necessary for the description of nuclides in this part of the nuclear chart. The effective interaction is derived by monopole corrections of the realistic G matrix. We reproduce essential nuclear properties, such as subshell closures in {sup 96}Zr and {sup 98}Zr. The spherical-to-deformed shape transition in {sup 100}Zr is addressed as well.

Sieja, K. [GSI-Helmholtzzentrum fuer Schwerionenforschung mbH., Planckstrasse 1, D-64-220 Darmstadt (Germany); Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Nowacki, F. [Institute Pluridisciplinaire Hubert Curien, 23 rue du Loess, Strasbourg (France); Langanke, K. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main (Germany); Martinez-Pinedo, G. [GSI-Helmholtzzentrum fuer Schwerionenforschung mbH., Planckstrasse 1, D-64-220 Darmstadt (Germany)

2009-06-15T23:59:59.000Z

419

CONTROL SYSTEM FOR ISOTOPE SEPARATING APPARATUS  

DOE Patents (OSTI)

A method is described for controlling the position of the ion beams in a calutron used for isotope separation. The U/sup 238/ beams is centered over the U/sup 235/ receiving pocket, the operator monitoring the beam until a maximum reading is achieved on the meter connected to that pocket. Then both beams are simultaneously shifted by a preselected amount to move the U/sup 235/ beam over the U/sup 235/ pocket. A slotted door is placed over the entrance to that pocket during the U/sup 238/ beam centering to reduce the contamination to the pocket, while allowing enough beam to pass for monitoring purposes.

Barnes, S.W.

1960-01-26T23:59:59.000Z

420

Laser-assisted isotope separation of tritium  

DOE Patents (OSTI)

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.

Herman, Irving P. (Castro Valley, CA); Marling, Jack B. (Livermore, CA)

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Hydrogen Isotope Permeation In Elastomeric Materials  

SciTech Connect

The permeabilities of elastomeric and polymeric materials to hydrogen isotopes were measured at room temperature. The technique for measuring permeation rates is based on the following constant-volume method: a fixed pressure of gas is applied to one side of the specimen to be studied and the permeability constant is determined from the observed rate of pressure increase in an initially evacuated volume on the other side of the specimen. Permeability constants for hydrogen, deuterium, and tritium were measured for Mylar, Teflon, Kapton, Saran, Buna-N, and latex rubber. Results were compared with literature values for hydrogen and deuterium where available and showed excellent agreement.

Steinmeyer, R. H.; Braun, J. D.

1976-03-01T23:59:59.000Z

422

EMSL: Capabilities: Mass Spectrometry: Next-Generation Mass Spectrometry  

NLE Websites -- All DOE Office Websites (Extended Search)

Next-Generation Mass Spectrometry Next-Generation Mass Spectrometry Additional Information Meet the Mass Spectrometry Experts Related EMSL User Projects Mass Spectrometry Tools are Applied to all Science Themes Next-Generation Mass Spectrometry Proteomics Research Resource for Integrative Biology Biological and Environmental Research - PNNL Proteomics PNNL's Biological MS Data and Software Distribution Center Mass Spectrometry brochure EMSL is committed to offering state-of-the-art instruments to its users. At a workshop in January of 2008, EMSL mass spectrometry experts joined experts from many universities, private companies, and government institutions and laboratories at a conference held at the National High Magnetic Field Laboratory in Tallahassee Florida. Workshop participants reviewed the state of the art of high-performance mass spectrometers,

423

Strange and charm meson masses from twisted mass lattice QCD  

E-Print Network (OSTI)

We present first results of a 2+1+1 flavor twisted mass lattice QCD computation of strange and charm meson masses. We focus on D and D_s mesons with spin J = 0,1 and parity P = -,+.

Martin Kalinowski; Marc Wagner

2012-12-03T23:59:59.000Z

424

Ion exchange separation and mass spectrometric analysis of uranium for solutions containing plutonium  

SciTech Connect

An ion exchange technique separates plutonium from uranium using Dowex-1 resin and a methanol--HCl plutonium elutriant. The method is applicable to both trace uranium determination and uranium isotopic distribution analysis by mass spectrometry. Distribution coefficients for plutonium, and elution curves for uranium and plutonium are shown. For uranium analysis the percent relative standard deviation is 0.8 at 120-2400 micrograms uranium per gram plutonium and 5.0 at 5 micrograms uranium per gram plutonium. (auth)

McBride, K.C.

1975-06-01T23:59:59.000Z

425

Stable Isotopes (O, H, and S) in the Muteh Gold Deposit, Golpaygan Area, Iran  

SciTech Connect

The Muteh gold district with nine gold deposits is located in the Sanandaj-Sirjan metamorphic zone. Gold mineralization occurs in a pre-Permian complex which mainly consists of green schists, meta-volcanics, and gneiss rocks. Shear zones are the host of gold mineralization. Gold paragenesis minerals include pyrite, chalcopyrite, pyrrhotite, and secondary minerals. Pyrites occur as pre-, syn-, and post-metamorphism minerals. To determine the source of the ore-bearing fluids, fifty samples were selected for petrographical and stable isotope studies. The mean values of 12.4 per mille , and -42 per mille for {delta}{sup 18}O and {delta}D isotopes, respectively, and a mean value of 7.75 per mille of calculated fractionation factors for {delta}{sup 18}O H{sub 2}O, from quartz veins indicate that metamorphic host rocks are the most important source for the fluids and gold mineralization. Three generations of pyrite can be distinguished showing a wide range of {delta}{sup 34}S. Gold mineralization is closely associated with intense hydrothermal alteration along the ductile shear zones. The characteristics of the gold mineralization in the study area are similar to those of orogenic gold deposits elsewhere.

Abdollahi, M. J. [Shahid Bahonar University, Department of Geology (Iran, Islamic Republic of)], E-mail: kmgbkh@gmail.com; Karimpour, M. H. [Ferdousi University, Department of Geology (Iran, Islamic Republic of); Kheradmand, A. [Shahid Bahonar University, Department of Geology (Iran, Islamic Republic of); Zarasvandi, A. R. [Shahid Chamran University, Department of Geology (Iran, Islamic Republic of)

2009-06-15T23:59:59.000Z

426

"Gravitational mass" of information?  

E-Print Network (OSTI)

We hypothesize possible new types of forces that would be the result of new types of interactions, static and a slow transient, between objects with related information contents (pattern). Such mechanism could make material composition dependence claimed by Fishbach, et al in Eotvos type experiments plausible. We carried out experiments by using a high-resolution scale with the following memories: USB-2 flash drives (1-16GB), DVD and CD disks to determine if such an interaction exist/detectable with a scale resolution of 10 microgram with these test objects. We applied zero information, white noise and 1/f noise type data. Writing or deleting the information in any of these devices causes peculiar negative weight transients, up to milligrams (mass fraction around 10^-5), which is followed by various types of relaxation processes. These relaxations have significantly different dynamics compared to transients observed during cooling after stationary external heating. Interestingly, a USB-1 MP3 player has also developed comparable transient mass loss during playing music. A classical interpretation of the negative weight transients could be absorbed water in hygroscopic components however comparison of relaxation time constants with air humidity data does not support an obvious explanation. Another classical interpretation with certain contribution is the lifting Bernoulli force caused by the circulation due to convection of the warm air. However, in this case all observed time constants with a device should have been the same unless some hidden parameter causes the observed variations. Further studies are warranted to clarify if there is indeed a new force, which is showing up as negative mass at weight measurement when high-density structural information is changed or read out (measured).

Laszlo B. Kish

2007-11-08T23:59:59.000Z

427

MassMass transfer andtransfer and separation technologyseparation technology  

E-Print Network (OSTI)

Driving force Apparatus Heat exchange Energy T Heat exchanger Gas absorption Mass G L c y-y* Packed towerGas absorption Mass G L c, y-y* Packed tower, or tray column Gas desorption Mass L G c, y*-y Packed tower tower, or tray column and B from a mix Vaporisation cooling Energy, water h (enthalpy) Spray tower

Zevenhoven, Ron

428

MASS SPECTROMETER LEAK  

DOE Patents (OSTI)

An improved valve is described for precisely regulating the flow of a sample fluid to be analyzed, such as in a mass spectrometer, where a gas sample is allowed to "leak" into an evacuated region at a very low, controlled rate. The flow regulating valve controls minute flow of gases by allowing the gas to diffuse between two mating surfaces. The structure of the valve is such as to prevent the corrosive feed gas from contacting the bellows which is employed in the operation of the valve, thus preventing deterioration of the bellows.

Shields, W.R.

1960-10-18T23:59:59.000Z

429

HIGEE Mass Transfer  

E-Print Network (OSTI)

Distillation, absorption, and gas stripping have traditionally been performed in tall columns utilizing trays or packing. Columns perform satisfactorily, but have characteristics which may be disadvantages in some applications: Large size, particularly height; high weight; high cost of installation; difficulty in modularization; foaming for certain systems; must be vertical, especially for trayed towers; large liquid inventory; difficulty in modifying column internals once installed; start up time to reach steady state conditions in excessive. Many of these disadvantages can be overcome by use of HIGEE, an innovative vapor-liquid mass transfer system which utilizes a rotating bed of packing to achieve high efficiency separations, and consequent reduction in size and weight.

Mohr, R. J.; Fowler, R.

1986-06-01T23:59:59.000Z

430

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

E-Print Network (OSTI)

York, K. Rankama, Isotope Geology, McGraw-Hill, New York,geochronometry and isotope geology. elements report. ofisotopes were utilized in the research areas and geology,

Zisman, M.S.

2010-01-01T23:59:59.000Z

431

Expert Panel: Forecast Future Demand for Medical Isotopes  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Expert Panel: Expert Panel: Forecast Future Demand for Medical Isotopes March 1999 Expert Panel: Forecast Future Demand for Medical Isotopes September 25-26, 1998 Arlington, Virginia The Expert Panel ............................................................................................. Page 1 Charge To The Expert Panel........................................................................... Page 2 Executive Summary......................................................................................... Page 3 Introduction ...................................................................................................... Page 4 Rationale.......................................................................................................... Page 6 Economic Analysis...........................................................................................

432

Tracking the lithium isotopic evolution of the mantle using carbonatites  

E-Print Network (OSTI)

Tracking the lithium isotopic evolution of the mantle using carbonatites Ralf Halama a,, William F. © 2007 Elsevier B.V. All rights reserved. Keywords: lithium isotopes; carbonatites; mantle geochemistry 1. Introduction Lithium (Li) is an incompatible element that is typi- cally enriched 10 to 50-fold in crustal

Mcdonough, William F.

433

Hafnium isotopes in Arctic Ocean water Bettina Zimmermann a  

E-Print Network (OSTI)

-GEOMAR, 24148 Kiel, Germany d Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50007, SEHafnium isotopes in Arctic Ocean water Bettina Zimmermann a , Don Porcelli b,*, Martin Frank c-104 05 Stockholm, Sweden e Department of Geology, Wayne State University, Detroit, MI 48202, USA f

Baskaran, Mark

434

Hydrogen isotope exchange in metal hydride columns  

DOE Green Energy (OSTI)

Several metal hydrides were shown to act as chromatographic media for hydrogen isotopes. The procedure was to equilibrate a column of hydride with flowing hydrogen, inject a small quantity of tritium tracer, and observe its elution behavior. Characteristic retention times were found. From these and the extent of widening of the tritium band, the heights equivalent to a theoretical plate could be calculated. Values of around 1 cm were obtained. The following are the metals whose hydrides were studied, together with the temperature ranges in which chromatographic behavior was observed: vanadium, 0 to 70/sup 0/C; zirconium, 500 to 600/sup 0/C; LaNi/sub 5/, -78 to +30/sup 0/C; Mg/sub 2/Ni, 300 to 375/sup 0/C; palladium, 0 to 70/sup 0/C. A dual-temperature isotope separation process based on hydride chromatography was demonstrated. In this, a column was caused to cycle between two temperatures while being supplied with a constant stream of tritium-traced hydrogen. Each half-cycle was continued until ''breakthrough,'' i.e., until the tritium concentration in the effluent was the same as that in the feed. Up to that point, the effluent was enriched or depleted in tritium, by up to 20%.

Wiswall, R; Reilly, J; Bloch, F; Wirsing, E

1977-11-21T23:59:59.000Z

435

Sandia National Laboratories Medical Isotope Reactor concept.  

SciTech Connect

This report describes the Sandia National Laboratories Medical Isotope Reactor and hot cell facility concepts. The reactor proposed is designed to be capable of producing 100% of the U.S. demand for the medical isotope {sup 99}Mo. The concept is novel in that the fuel for the reactor and the targets for the {sup 99}Mo production are the same. There is no driver core required. The fuel pins that are in the reactor core are processed on a 7 to 21 day irradiation cycle. The fuel is low enriched uranium oxide enriched to less than 20% {sup 235}U. The fuel pins are approximately 1 cm in diameter and 30 to 40 cm in height, clad with Zircaloy (zirconium alloy). Approximately 90 to 150 fuel pins are arranged in the core in a water pool {approx}30 ft deep. The reactor power level is 1 to 2 MW. The reactor concept is a simple design that is passively safe and maintains negative reactivity coefficients. The total radionuclide inventory in the reactor core is minimized since the fuel/target pins are removed and processed after 7 to 21 days. The fuel fabrication, reactor design and operation, and {sup 99}Mo production processing use well-developed technologies that minimize the technological and licensing risks. There are no impediments that prevent this type of reactor, along with its collocated hot cell facility, from being designed, fabricated, and licensed today.

Coats, Richard Lee; Dahl, James J.; Parma, Edward J., Jr.

2010-04-01T23:59:59.000Z

436

Global Security, Medical Isotopes, and Nuclear Science  

Science Conference Proceedings (OSTI)

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.

Ahle, L E

2007-09-17T23:59:59.000Z

437

Geothermal reservoir temperatures estimated from the oxygen isotope  

Open Energy Info (EERE)

reservoir temperatures estimated from the oxygen isotope reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Geothermal reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes Details Activities (3) Areas (3) Regions (0) Abstract: The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested as a geothermometer in three areas of the western United States. Limited analyses of spring and borehole fluids and existing experimental rate studies suggest that dissolved sulfate and water are probably in isotopic equilibrium in all reservoirs of significant size with temperatures above

438

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Oak Ridge National Laboratory High Flux Isotope Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR February 2007 A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2007 assessment of the Engineering Program portion of an Operational Readiness Review of the Oak Ridge National Laboratory, High Flux Isotope Reactor. CRADs provide a recommended approach and the types of information to gather to assess elements of a DOE contractor's programs. CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR More Documents & Publications

439

Expert Panel: Forecast Future Demand for Medical Isotopes | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Expert Panel: Forecast Future Demand for Medical Isotopes Expert Panel: Forecast Future Demand for Medical Isotopes Expert Panel: Forecast Future Demand for Medical Isotopes The Expert Panel has concluded that the Department of Energy and National Institutes of Health must develop the capability to produce a diverse supply of radioisotopes for medical use in quantities sufficient to support research and clinical activities. Such a capability would prevent shortages of isotopes, reduce American dependence on foreign radionuclide sources and stimulate biomedical research. The expert panel recommends that the U.S. government build this capability around either a reactor, an accelerator or a combination of both technologies as long as isotopes for clinical and research applications can be supplied reliably, with diversity in adequate

440

Cancer-fighting treatment gets boost from Isotope Production Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

Cancer-fighting treatment gets boost from Isotope Production Cancer-fighting treatment gets boost from Isotope Production Facility Cancer-fighting treatment gets boost from Isotope Production Facility New capability expands existing program, creates treatment product in quantity. April 13, 2012 Medical Isotope Work Moves Cancer Treatment Agent Forward Medical Isotope Work Moves Cancer Treatment Agent Forward - Los Alamos scientist Meiring Nortier holds a thorium foil test target for the proof-of-concept production experiments. Research indicates that it will be possible to match current annual, worldwide production of Ac-225 in just two to five days of operations using the accelerator at Los Alamos and analogous facilities at Brookhaven. Alpha particles are energetic enough to destroy cancer cells but are unlikely to move beyond a tightly controlled target region and destroy

Note: This page contains sample records for the topic "occurring isotopes mass" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

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

Open Energy Info (EERE)

Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal System Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal System Details Activities (3) Areas (1) Regions (0) Abstract: Fluids from springs, fumaroles, and wells throughout Dixie Valley, NV were analyzed for noble gas abundances and isotopic compositions. The helium isotopic compositions of fluids produced from the Dixie Valley geothermal field range from 0.70 to 0.76 Ra, are among the highest values in the valley, and indicate that similar to 7.5% of the total helium is derived from the mantle. A lack of recent volcanics or other potential sources requires flow of mantle-derived helium up along the

442

CRAD, Management - Oak Ridge National Laboratory High Flux Isotope Reactor  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Oak Ridge National Laboratory High Flux Isotope Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR CRAD, Management - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR February 2007 A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2007 assessment of the Management portion of an Operational Readiness Review of the Oak Ridge National Laboratory High Flux Isotope Reactor. CRADs provide a recommended approach and the types of information to gather to assess elements of a DOE contractor's programs. CRAD, Management - Oak Ridge National Laboratory High Flux Isotope Reactor Contractor ORR More Documents & Publications

443

CRAD, Training - Oak Ridge National Laboratory High Flux Isotope Reactor |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reactor Reactor CRAD, Training - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2007 assessment of the Training Program in preparation for restart of the Oak Ridge National Laboratory High Flux Isotope Reactor. RADs provide a recommended approach and the types of information to gather to assess elements of a DOE contractor's programs. CRAD, Training - Oak Ridge National Laboratory High Flux Isotope Reactor More Documents & Publications CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Training - Oak Ridge National Laboratory High Flux Isotope Reactor

444

CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reactor Reactor CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2007 assessment of the Maintenance Program in preparation for restart of the Oak Ridge National Laboratory High Flux Isotope Reactor. CRADs provide a recommended approach and the types of information to gather to assess elements of a DOE contractor's programs. CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor More Documents & Publications CRAD, Safety Basis - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor

445

Isotopic Analysis-Fluid At Yellowstone Caldera Geothermal Region (1977) |  

Open Energy Info (EERE)

Isotopic Analysis-Fluid At Yellowstone Caldera Geothermal Region (1977) Isotopic Analysis-Fluid At Yellowstone Caldera Geothermal Region (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-Fluid At Yellowstone Caldera Geothermal Region (1977) Exploration Activity Details Location Yellowstone Caldera Geothermal Region Exploration Technique Isotopic Analysis-Fluid Activity Date 1977 Usefulness not indicated DOE-funding Unknown Exploration Basis Estimate deep reservoir temperature Notes The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested. Methods are described to calculate the effects of boiling and dilution. The geothermometer, is applied to thermal systems of Yellowstone Park, Wyoming, Long Valley, California, and Raft River, Idaho to estimate deep reservoir temperatures

446

CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2007 assessment of the Nuclear Safety Program in preparation for restart of the Oak Ridge National Laboratory High Flux Isotope Reactor. CRADs provide a recommended approach and the types of information to gather to assess elements of a DOE contractor's programs. CRAD, Nuclear Safety - Oak Ridge National Laboratory High Flux Isotope Reactor More Documents & Publications CRAD, Engineering - Oak Ridge National Laboratory High Flux Isotope Reactor

447

Fractionation of Boron Isotopes in Icelandic Hydrothermal Systems  

DOE Green Energy (OSTI)

Boron isotope ratios have been determined in a variety of different geothermal waters from hydrothermal systems across Iceland. Isotope ratios from the high temperature meteoric water recharged systems reflect the isotope ratio of the host rocks without any apparent fractionation. Seawater recharged geothermal systems exhibit more positive {delta}{sup 11}B values than the meteoric water recharged geothermal systems. Water/rock ratios can be assessed from boron isotope ratios in the saline hydrothermal systems. Low temperature hydrothermal systems also exhibit more positive {delta}{sup 11}B than the high temperature systems, indicating fractionation of boron due to adsorption of the lighter isotope onto secondary minerals. Fractionation of boron in carbonate deposits may indicate the level of equilibrium attained within the systems.

Aggarwal, J.K.; Palmer, M.R.

1995-01-01T23:59:59.000Z

448

Determining the neutrino mass hierarchy  

Science Conference Proceedings (OSTI)

In this proceedings I review the physics that future experiments will use to determine the neutrino mass hierarchy.

Parke, Stephen J.; /Fermilab

2006-07-01T23:59:59.000Z

449

Mass Transport within Soils  

Science Conference Proceedings (OSTI)

Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated zone with three major horizons, the saturated zone can be further divided into other zones based on hydraulic and geologic conditions. Wetland soils are a special and important class in which near-saturation conditions exist most of the time. When a contaminant is added to or formed in a soil column, there are several mechanisms by which it can be dispersed, transported out of the soil column to other parts of the environment, destroyed, or transformed into some other species. Thus, to evaluate or manage any contaminant introduced to the soil column, one must determine whether and how that substance will (1) remain or accumulate within the soil column, (2) be transported by dispersion or advection within the soil column, (3) be physically, chemically, or biologically transformed within the soil (i.e., by hydrolysis, oxidation, etc.), or (4) be transported out of the soil column to another part of the environment through a cross-media transfer (i.e., volatilization, runoff, ground water infiltration, etc.). These competing processes impact the fate of physical, chemical, or biological contaminants found in soils. In order to capture these mechanisms in mass transfer models, we must develop mass-transfer coefficients (MTCs) specific to soil layers. That is the goal of this chapter. The reader is referred to other chapters in this Handbook that address related transport processes, namely Chapter 13 on bioturbation, Chapter 15 on transport in near-surface geological formations, and Chapter 17 on soil resuspention. This chapter addresses the following issues: the nature of soil pollution, composition of soil, transport processes and transport parameters in soil, transformation processes in soil, mass-balance models, and MTCs in soils. We show that to address vertical heterogeneity in soils in is necessary to define a characteristic scaling depth and use this to establish process-based expressions for soil MTCs. The scaling depth in soil and the corresponding MTCs depend strongly on (1) the composition of the soil and physical state of the soil, (2) the chemical and physic

McKone, Thomas E.

2009-03-01T23:59:59.000Z

450

Isotopic Yield Distributions of Transfer- and Fusion-Induced Fission from 238U+12C Reactions in Inverse Kinematics  

E-Print Network (OSTI)

A novel method to access the complete identification in atomic number Z and mass A of fragments produced in low-energy fission of actinides is presented. This method, based on the use of multi- nucleon transfer and fusion reactions in inverse kinematics, is applied in this work to reactions between a 238U beam and a 12C target to produce and induce fission of moderately excited actinides. The fission fragments are detected and fully identified with the VAMOS spectrometer of GANIL, allowing the measurement of fragment yields of several hundreds of isotopes in a range between A ~ 80 and ~ 160, and from Z ~ 30 to ~ 64. For the first time, complete isotopic yield distributions of fragments from well-defined fissioning systems are available. Together with the precise measurement of the fragment emission angles and velocities, this technique gives further insight into the nuclear-fission process.

M. Caamaño; O. Delaune; F. Farget; X. Derkx; K. -H. Schmidt; L. Audouin; C. -O. Bacri; G. Barreau; J. Benlliure; E. Casarejos; A. Chbihi; B. Fernandez-Dominguez; L. Gaudefroy; C. Golabek; B. Jurado; A. Lemasson; A. Navin; M. Rejmund; T. Roger; A. Shrivastava; C. Schmitt

2013-04-09T23:59:59.000Z

451

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry are described. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field. 8 figs.

McComas, D.J.; Nordholt, J.E.

1992-12-01T23:59:59.000Z

452

Linear electric field mass spectrometry  

DOE Patents (OSTI)

A mass spectrometer and methods for mass spectrometry. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field.

McComas, David J. (Los Alamos, NM); Nordholt, Jane E. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

453

Surface kinetic model for isotopic and trace element fractionation during precipitation of calcite from aqueous solution  

SciTech Connect

A surface reaction kinetic model is developed for predicting Ca isotope fractionation and metal/Ca ratios of calcite as a function of rate of precipitation from aqueous solution. The model is based on the requirements for dynamic equilibrium; i.e. proximity to equilibrium conditions is determined by the ratio of the net precipitation rate (R{sub p}) to the gross forward precipitation rate (R{sub f}), for conditions where ionic transport to the growing crystal surface is not rate-limiting. The value of R{sub p} has been experimentally measured under varying conditions, but the magnitude of R{sub f} is not generally known, and may depend on several factors. It is posited that, for systems with no trace constituents that alter the surface chemistry, R{sub f} can be estimated from the bulk far-from-equilibrium dissolution rate of calcite (R{sub b} or k{sub b}), since at equilibrium R{sub f} = R{sub b}, and R{sub p} = 0. Hence it can be inferred that R{sub f} {approx} R{sub p} + R{sub b}. The dissolution rate of pure calcite is measureable and is known to be a function of temperature and pH. At given temperature and pH, equilibrium precipitation is approached when R{sub p} (= R{sub f} - R{sub b}) << R{sub b}. For precipitation rates high enough that R{sub p} >> R{sub b}, both isotopic and trace element partitioning are controlled by the kinetics of ion attachment to the mineral surface, which tend to favor more rapid incorporation of the light isotopes of Ca and discriminate weakly between trace metals and Ca. With varying precipitation rate, a transition region between equilibrium and kinetic control occurs near R{sub p} {approx} R{sub b} for Ca isotopic fractionation. According to this model, Ca isotopic data can be used to estimate R{sub f} for calcite precipitation. Mechanistic models for calcite precipitation indicate that the molecular exchange rate is not constant at constant T and pH, but rather is dependent also on solution saturation state and hence R{sub p}. Allowing R{sub b} to vary as R{sub p}{sup 1/2}, consistent with available precipitation rate studies, produces a better fit to some trace element and isotopic data than a model where R{sub b} is constant. This model can account for most of the experimental data in the literature on the dependence of {sup 44}Ca/{sup 40}Ca and metal/Ca fractionation in calcite as a function of precipitation rate and temperature, and also accounts for {sup 18}O/{sup 16}O variations with some assumptions. The apparent temperature dependence of Ca isotope fractionation in calcite may stem from the dependence of R{sub b} on temperature; there should be analogous pH dependence at pH < 6. The proposed model may be valuable for predicting the behavior of isotopic and trace element fractionation for a range of elements of interest in low-temperature aqueous geochemistry. The theory presented is based on measureable thermo-kinetic parameters in contrast to models that equire hyper-fast diffusivity in near-surface layers of the solid.

DePaolo, D.

2010-10-15T23:59:59.000Z

454

Influence of current mass on the spatially inhomogeneous chiral condensate  

E-Print Network (OSTI)

It is known that, in the chiral limit, spatially inhomogeneous chiral condensate occurs in the Nambu-Jona-Lasinio (NJL) model at finite density within a mean-field approximation. We study here how an introduction of current quark mass affects the ground state with the spatially inhomogeneous chiral condensate. Numerical calculations show that, even if the current quark mass is introduced, the spatially inhomogeneous chiral condensate can take place. In order to obtain the ground state, the thermodynamic potential is calculated with a mean-field approximation. The influence of finite current mass on the thermodynamic potential consists of following two parts. One is a part coming from the field energy of the condensate, which favors inhomogeneous chiral condensate. The other is a part coming from the Dirac sea and the Fermi sea, which favors homogeneous chiral condensate. We also find that when the spatially inhomogeneous chiral condensate occurs, the baryon number density becomes spatially inhomogeneous.

Shinji Maedan

2009-08-05T23:59:59.000Z

455

It's Elemental - Isotopes of the Element Californium  

NLE Websites -- All DOE Office Websites (Extended Search)

Mass Number Half-life Decay Mode Branching Percentage 237 0.8 seconds Spontaneous Fission 70.00% Alpha Decay 30.00% 238 21 milliseconds Spontaneous Fission 100.00% 239 39...

456

It's Elemental - Isotopes of the Element Seaborgium  

NLE Websites -- All DOE Office Websites (Extended Search)

Mass Number Half-life Decay Mode Branching Percentage 258 2.9 milliseconds Spontaneous Fission < 100.00% Alpha Decay (suspected) No Data Available 259 0.32 seconds Alpha Decay...

457

It's Elemental - Isotopes of the Element Rutherfordium  

NLE Websites -- All DOE Office Websites (Extended Search)

Mass Number Half-life Decay Mode Branching Percentage 253 48 microseconds Spontaneous Fission < 100.00% Alpha Decay No Data Available Alpha Decay 50.00% Spontaneous Fission ...

458

Baryon Mass Extrapolation  

E-Print Network (OSTI)

Consideration of the analytical properties of pion-induced baryon self-energies leads to new functional forms for the extrapolation of light baryon masses. These functional forms reproduce the leading non-analytic behavior of chiral perturbation theory, the correct heavy-quark limit and have the advantage of containing information on the extended structure of hadrons. The forms involve only three unknown parameters which may be optimized by fitting to present lattice data. Recent dynamical fermion results from CP-PACS and UK-QCD are extrapolated using these new functional forms. We also use these functions to probe the limit of the chiral perturbative regime and shed light on the applicability of chiral perturbation theory to the extrapolation of present lattice QCD results.

Derek B. Leinweber; Anthony W. Thomas; Kazuo Tsushima; Stewart V. Wright

1999-09-14T23:59:59.000Z

459

Radiological Dose Assessment Related to Management of Naturally Occurring Radioactive Materials Generated by the Petroleum Industry  

NLE Websites -- All DOE Office Websites (Extended Search)

Tebes is affiliated with the University of Illinois. Tebes is affiliated with the University of Illinois. ANL/EAD-2 Radiological Dose Assessment Related to Management of Naturally Occurring Radioactive Materials Generated by the Petroleum Industry by K.P. Smith, D.L. Blunt, G.P. Williams, and C.L. Tebes * Environmental Assessment Division Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 September 1996 Work sponsored by the United States Department of Energy, Office of Policy iii CONTENTS ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii NOTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

460

Bibliography of reports, papers, and presentations on naturally occurring radioactive material (NORM) in petroleum industry wastes  

Science Conference Proceedings (OSTI)

This bibliography was created to support projects conducted by Argonne National Laboratory (ANL) addressing issues related to naturally occurring radioactive material (NORM) in petroleum industry wastes. The bibliography provides citations for many of the available published reports, papers, articles, and presentations on petroleum industry NORM. In the past few years, the rapid expansion of NORM treatment and disposal technologies, the efforts to characterize NORM wastes and their associated potential risks, and the promulgation of state-level NORM regulatory programs have been well-documented in project reports and in papers presented at technical conferences and symposia. There are 221 citations.

Smith, K.P.; Wilkey, M.L.; Hames, R.D.

1997-07-01T23:59:59.000Z

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