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Note: This page contains sample records for the topic "isotopic analysis isotopic" 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.


1

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

2

Atom trap trace analysis of krypton isotopes  

SciTech Connect (OSTI)

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

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

1999-11-17T23:59:59.000Z

3

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

Open Energy Info (EERE)

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

4

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

Open Energy Info (EERE)

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

5

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

Open Energy Info (EERE)

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

6

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

Open Energy Info (EERE)

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

7

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

Open Energy Info (EERE)

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

8

Isotopic Analysis- Gas At Dixie Valley Geothermal Area (Kennedy...  

Open Energy Info (EERE)

search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Gas At Dixie Valley Geothermal Area (Kennedy & Soest, 2006) Exploration Activity Details...

9

UW Cosmogenic Isotopes Al-Be 1 EXTRACTION OF Al & Be FROM QUARTZ FOR ISOTOPIC ANALYSIS  

E-Print Network [OSTI]

UW Cosmogenic Isotopes Al-Be 1 EXTRACTION OF Al & Be FROM QUARTZ FOR ISOTOPIC ANALYSIS Summary This method is used to separate Al and Be for AMS analysis from pure quartz samples. After adding Be carrier, quartz is dissolved in HF. The solution is sub-sampled for determination of total Al content, then dried

Stone, John

10

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

Open Energy Info (EERE)

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

11

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

Open Energy Info (EERE)

of the Roosevelt Hot Springs Geothermal Area. Notes Stable isotope analysis of thermal fluids determined meteoric origin primarily from the Mineral Mountains with a small...

12

Isotopic Analysis- Rock At Kilauea East Rift Geothermal Area...  

Open Energy Info (EERE)

Technique Isotopic Analysis- Rock Activity Date 1989 - 2000 Usefulness not indicated DOE-funding Unknown Exploration Basis The purpose of this study was to analyze deep core...

13

Isotopic Analysis- Fluid At Kilauea East Rift Geothermal Area...  

Open Energy Info (EERE)

navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Kilauea East Rift Geothermal Area (Scholl, Et Al., 1993) Exploration...

14

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

Open Energy Info (EERE)

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

15

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

Open Energy Info (EERE)

Zone Region (Kennedy & Van Soest, 2007) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity...

16

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

Open Energy Info (EERE)

White, Et Al., 1992) Exploration Activity Details Location Valles Caldera - Redondo Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date - 1992 Usefulness...

17

Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs...  

Open Energy Info (EERE)

Activity: Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs Geothermal Area (White, Et Al., 1992) Exploration Activity Details Location Valles Caldera - Sulphur Springs...

18

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

Open Energy Info (EERE)

White, 1986) Exploration Activity Details Location Valles Caldera - Redondo Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date - 1986 Usefulness not...

19

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

Open Energy Info (EERE)

1971) prior to analysis by mass spectrometry. Water samples were analyzed for their oxygen isotope ratios using the carbon dioxide-equilibration method. Waters analyzed from the...

20

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

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Isotopic abundance in atom trap trace analysis  

DOE Patents [OSTI]

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

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

2014-03-18T23:59:59.000Z

22

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]

, 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...

Kim, Moon Koo

2004-11-15T23:59:59.000Z

23

THE ISOTOPES OF AMERICIUM  

E-Print Network [OSTI]

spectrographic analysis of the americium samples. It is a48 J'---_I" THE ISOTOPES OF AMERICIUM K. Street, Jr. , A.Elements THE ISOTOPES OF AMERICIUM K. Street, Jr. , A.

Street, K.; Ghiroso, A.; Seaborg, G.T.

2008-01-01T23:59:59.000Z

24

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

Open Energy Info (EERE)

permeable fluid flow pathways and the helium Isotopic composition of the surface fluids. The authors suggest that helium isotopes are the best and possibly the only...

25

Selection of Isotopes and Elements for Fuel Cycle Analysis  

SciTech Connect (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

26

from Isotope Production Facility  

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

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

27

Enabling online geospatial isotopic model development and analysis  

E-Print Network [OSTI]

Enabling online geospatial isotopic model development and analysis Hyojeong Lee1 , Lan Zhao1 leverages the computation resources available on the TeraGrid to perform geospatial data operations and geostatistical model calculations. It builds on a variety of open source technologies for GIS, geospatial data

Zhang, Tonglin

28

A direct and rapid leaf water extraction method for isotopic analysis  

E-Print Network [OSTI]

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

Yakir, Dan

29

Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs...  

Open Energy Info (EERE)

Jamie N. Gardner, Rosemary Vidale, Robert Charles (1985) Geochemistry and Isotopes of Fluids from Sulphur Springs, Valles Caldera, New Mexico Additional References Retrieved from...

30

Hanford Isotope Project strategic business analysis Cesium-137 (Cs-137)  

SciTech Connect (OSTI)

The purpose of this business analysis is to address the beneficial reuse of Cesium 137 (Cs-137) in order to utilize a valuable national asset and possibly save millions of tax dollars. Food irradiation is the front runner application along with other uses. This business analysis supports the objectives of the Department of Energy National Isotope Strategy distributed in August 1994 which describes the DOE plans for the production and distribution of isotope products and services. As part of the Department`s mission as stated in that document. ``The Department of Energy will also continue to produce and distribute other radioisotopes and enriched stable isotopes for medical diagnostics and therapeutics, industrial, agricultural, and other useful applications on a businesslike basis. This is consistent with the goals and objectives of the National Performance Review. The Department will endeavor to look at opportunities for private sector to co-fund or invest in new ventures. Also, the Department will seek to divest from ventures that can more profitably or reliably be operated by the private sector.``

NONE

1995-10-01T23:59:59.000Z

31

isotopic ratio | EMSL  

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

isotopic ratio isotopic ratio Leads No leads are available at this time. Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. Abstract: As a candidate...

32

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

SciTech Connect (OSTI)

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

Glover, S. E. (Samuel E.)

2003-01-01T23:59:59.000Z

33

Uncertainty analysis of densities and isotopics: Handling correlations  

SciTech Connect (OSTI)

This paper discusses two cases of correlated parameters in uncertainty analyses: (1) the case of measured mass, density, and volume or spatial dimension correlations; and (2) the case of measured material isotopics, where increasing one atom fraction must cause the others to decrease. In the first case, an equation is derived that has a term due to uncertain density, a term due to uncertain dimensions, and a term due to the correlation between density and dimensions. In a numerical test problem, this equation gives the same result as the standard equation that treats mass and dimensions independently. In the case of isotopics, an equation is derived relating the uncertainty due to uncertain isotopic fractions to the sensitivities to isotopic densities, which are easier to calculate. The equation is verified in a test problem. (authors)

Favorite, J. A.; Armstrong, J. C. [X-Computational Physics Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Burr, T. [Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

2013-07-01T23:59:59.000Z

34

argon isotope analysis: Topics by E-print Network  

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

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

35

Stable isotope studies  

SciTech Connect (OSTI)

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

36

Isotope Science and Production  

E-Print Network [OSTI]

of Energy National Isotope Program http://www.nuclear.energy.gov/isotopes/nelsotopes2a.html Isotopes for Environmental Science Isotopes produced at Los Alamos National Laboratory are used as environmental tracers change and its effects. Los Alamos National Laboratory can produce Si-32 needed for oceanographic tracing

37

Variations in the diet of introduced Norway rats (Rattus norvegicus) inferred using stable isotope analysis  

E-Print Network [OSTI]

Variations in the diet of introduced Norway rats (Rattus norvegicus) inferred using stable isotope predators; island ecosystem conservation; stable isotope analysis; Norway rats; diet. Correspondence Heather of introduced Norway rats Rattus norvegicus has raised concerns for the fate of the large least auklet Aethia

Jones, Ian L.

38

Intrinsic Primary and Secondary Hydrogen Kinetic Isotope Effects for Alanine Racemase from Global Analysis of  

E-Print Network [OSTI]

Intrinsic Primary and Secondary Hydrogen Kinetic Isotope Effects for Alanine Racemase from Global of the intrinsic primary kinetic isotope effects, the lower boundary on the energy of the quinonoid intermediate, making alanine racemase an attractive target for antibacterials. Global analysis of protiated

Toney, Michael

39

Comprehensive analysis of metabolic pathways through the combined use of multiple isotopic tracers  

E-Print Network [OSTI]

Metabolic Flux Analysis (MFA) has emerged as a tool of great significance for metabolic engineering and the analysis of human metabolic diseases. An important limitation of MFA, as carried out via stable isotope labeling ...

Antoniewicz, Maciek Robert

2006-01-01T23:59:59.000Z

40

Transportation of medical isotopes  

SciTech Connect (OSTI)

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

Nielsen, D.L.

1997-11-19T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Hybrid isotope separation scheme  

DOE Patents [OSTI]

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

Maya, J.

1991-06-18T23:59:59.000Z

42

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

43

Stable isotope enrichment  

SciTech Connect (OSTI)

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

Egle, Brian

2014-07-14T23:59:59.000Z

44

EMSL - isotopic ratio  

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

isotopic-ratio en Magnesium behavior and structural defects in Mg+ ion implanted silicon carbide. http:www.emsl.pnl.govemslwebpublicationsmagnesium-behavior-and-structural-def...

45

Stable isotope enrichment  

ScienceCinema (OSTI)

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

Egle, Brian

2014-07-15T23:59:59.000Z

46

Discovery of the Tungsten Isotopes  

E-Print Network [OSTI]

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

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

2009-03-25T23:59:59.000Z

47

Discovery of the Tin Isotopes  

E-Print Network [OSTI]

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

S. Amos; M. Thoennessen

2010-09-08T23:59:59.000Z

48

Discovery of the tungsten isotopes  

SciTech Connect (OSTI)

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

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

2010-05-15T23:59:59.000Z

49

Discovery of the Tungsten Isotopes  

E-Print Network [OSTI]

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

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

2009-01-01T23:59:59.000Z

50

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

1988-01-01T23:59:59.000Z

51

Photochemical isotope separation  

DOE Patents [OSTI]

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

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

1987-01-01T23:59:59.000Z

52

Photochemical isotope separation  

DOE Patents [OSTI]

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

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

1987-04-28T23:59:59.000Z

53

SIMS ISOTOPIC ANALYSIS OF INTERPLANETARY DUST FROM SPACE-EXPOSED AEROGEL. F. J. Stadermann  

E-Print Network [OSTI]

SIMS ISOTOPIC ANALYSIS OF INTERPLANETARY DUST FROM SPACE-EXPOSED AEROGEL. F. J. Stadermann 1: Aerogel is the medium of choice for the intact capture of small particles in space, because it is capable materials [1, 2]. After space-exposed aerogel is returned to the laboratory, the first step of analysis

54

Feasibility study of plutonium isotopic analysis of resin beads by nondestructive gamma-ray spectroscopy  

SciTech Connect (OSTI)

We have initiated a feasibility study on the use of nondestructive low-energy gamma-ray spectroscopy for plutonium isotopic analysis on resin beads. Seven resin bead samples were measured, with each sample containing an average of 9 ..mu..g of plutonium; the isotopic compositions of the samples varied over a wide range. The gamma-ray spectroscopy results, obtained from 4-h counting-time measurements, were compared with mass spectrometry results. The average ratios of gamma-ray spectroscopy to mass spectrometry were 1.014 +- 0.025 for /sup 238/Pu//sup 239/Pu, 0.996 +- 0.018 for /sup 240/Pu//sup 239/Pu, and 0.980 +- 0.038 for /sup 241/Pu//sup 239/Pu. The rapid, automated, and accurate nondestructive isotopic analysis of resin beads may be very useful to process technicians and International Atomic Energy Agency inspectors. 3 refs., 1 fig., 3 tabs.

Li, T.K.

1985-01-01T23:59:59.000Z

55

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

SciTech Connect (OSTI)

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

56

Prospects for large dynamic range isotope analysis using photon burst mass spectrometry  

SciTech Connect (OSTI)

Photon Burst Mass Spectrometry is a relatively new and untried method which may complement and extend the impressive achievements of Resonance Ionization Mass Spectrometry and Accelerator Mass Spectrometry in the field of large dynamic range isotope analysis. Theoretical predictions indicate that measurements in the 10/sup /minus/11/ to 10/sup /minus/15/ range are possible in a reasonable period of time with zero background. Experimentally only the very first demonstrations of PBMS with stable isotopes have been completed. 8 refs., 1 fig., 1 tab.

Fairbank, W.M. Jr.; LaBelle, R.D.; Keller, R.A.; Miller, C.M.; Poths, J.; Fearey, B.L.

1988-01-01T23:59:59.000Z

57

Water Research 38 (2004) 25292536 The use of isotopic and lipid analysis techniques linking  

E-Print Network [OSTI]

, ethylbenzene and xylenes (i.e., BTEX) are common ground water pollutants that threaten water suppliesWater Research 38 (2004) 2529­2536 The use of isotopic and lipid analysis techniques linking, C16:0 fatty acid might be a useful biomarker for tracking contaminant degradation and 13 C flow

Alvarez, Pedro J.

58

GRPAUT: a program for Pu isotopic analysis (a user's guide). ISPO task A. 76  

SciTech Connect (OSTI)

GRPAUT is a modular program for performing automated Pu isotopic analysis supplied to the International Atomic Energy Agency (IAEA) per ISPO Task A.76. Section I of this user's guide for GRPAUT presents an overview of the various programs and disk files that are used in performing a Pu isotopic analysis. Section II describes the program GRFEDT which is used in creating and editing the analysis parameter file that contains all the spectroscopic information needed at runtime by GRPAUT. An example of the dialog and output of GRFEDT is shown in Appendix B. Section III describes the operation of the various GRPAUT modules: GRPNL2, the peak stripping module; EFFCH2, the efficiency calculation module; and ISOAUT, the isotopic calculation module. (A description of the peak fitting methodology employed by GRPNL2 is presented in Appendix A.) Finally, Section IV outlines the procedure for determining the peak shape constants for a detector system and describes the operation of the program used to create and edit the peak shape parameter files. An output of GRPAUT, showing an example of a complete isotopic analysis, is presented in Appendix C. Source listings of all the Fortran programs supplied to the Agency under ISPO Task A.76 are contained in Appendix E.

Fleissner, J G

1981-01-30T23:59:59.000Z

59

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

DOE Patents [OSTI]

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

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

2014-12-09T23:59:59.000Z

60

Purification of fire derived markers for lg scale isotope analysis C) using high performance liquid chromatography (HPLC)  

E-Print Network [OSTI]

Purification of fire derived markers for lg scale isotope analysis (d13 C, D14 C) using high successfully analyzed the 14 C content of individual benzene polycarboxy- lic acids with a sample size as small the expansion of isotopic BC studies to samples that have either been too small or strongly affected by non

Gilli, Adrian

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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.


61

Stable Isotope Protocols: Sampling and Sample Processing  

E-Print Network [OSTI]

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

Levin, Lisa A; Currin, Carolyn

2012-01-01T23:59:59.000Z

62

GENERATION OF RADIOXENON ISOTOPES  

SciTech Connect (OSTI)

With the continued population of the International Monitoring System (IMS) network and the certification of radioxenon laboratory systems it has become necessary to calibrate and test these systems using as many of the radioxenon isotopes as possible. Several very promising techniques have been explored recently that allow for convenient production of Xe-133, Xe-131m, the short-lived isotope Xe-135, and even the difficult to obtain Xe-133m. IMS national and international laboratories have traditionally obtained Xe-133 from medical isotope suppliers. The activity of these medical dose samples is extremely high (~ 740 MBq) and requires very careful fume hood work to dilute down to appropriate levels (~ 10 Bq). By waiting for 10 or more half-lives it is possible to reduce the handling regimen considerably, while also obtaining a strong Xe-131m signature due to its longer half-life (11.9 days). The short-lived isotope Xe-135 (9.14 hrs) and the longer lived parent nuclide Xe-133m (2.2 day half-life) are never present in these samples. To obtain these isotopes another source or technique is required. This paper will discuss the two techniques developed and implemented at Pacific Northwest National Lab (PNNL) and show the results obtained from each technique. The first is an in-house method that allows for on demand production of two of these isotopes, Xe-133 and Xe-135, using HEU and a modest flux neutron source. The second method uses a research reactor at the Pullman campus of Washington State University to produce Xe-133, Xe-133m and Xe-135.

McIntyre, Justin I.; Pratt, Sharon L.; Bowyer, Ted W.; Cooper, Matthew W.; Hayes, James C.; Heimbigner, Tom R.; Hubbard, Charles W.; Miley, Harry S.; Ripplinger, Mike D.

2008-09-23T23:59:59.000Z

63

The computerized identification of reactor-produced isotopes in an activation analysis environment  

E-Print Network [OSTI]

- ability of a complete, positive identification appears small. How- ever, with the addition of a least squares method of resolving interferences and the application of a figure indicating the value (figure-of-merit) placed on each elimination test...THE COMPUTERIZED IDENTIFICATION OF REACTOR-PRODUCED ISOTOP ' S IN AN ACTIVATION ANALYSIS ENVIRON&vIENT A Thesi. s by DANIEI. aOIIN SCHLUETER Submitted to the Grec'u&ate College of Texas ARM University in pa. tial fulfillment o...

Schlueter, Daniel John

1971-01-01T23:59:59.000Z

64

Elemental and isotopic analysis of inorganic salts by laser desorption ionization mass spectrometry  

SciTech Connect (OSTI)

Laser desorption ionization mass spectrometry is applied for the analysis of elements as well as their isotopic composition in different inorganic salts. At very low laser energies the inorganic ions are desorbed and ionized from the thin layer of the sample surface. The naturally occurring isotopes of alkali and silver ions are resolved using time of flight mass spectrometer. Further increase in laser energy shows the appearance of Al, Cr, and Fe ions in the mass spectra. This indicates the penetration laser beam beyond the sample surface leading to the ablation of sample target at higher energies. The simultaneous appearance of atomic ions from the sample target at relatively higher laser energies hampers the unambiguous identification of amino acid residues from the biomolecular ions in MALDI-MS.

Jayasekharan, T.; Sahoo, N. K. [Applied Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2013-02-05T23:59:59.000Z

65

Back-Trajectory Analysis and Source-Receptor Relationships: Particulate Matter and Nitrogen Isotopic Composition in  

E-Print Network [OSTI]

sources of nitrogen in rainwater collected at an urban receptor site in Raleigh, NC. The 15 N isotope Isotopic Composition in Rainwater Chris Occhipinti, Viney P. Aneja, William Showers, and Dev Niyogi ratio signa- tures of each sample were used to further differentiate between sources of the rainwater

Niyogi, Dev

66

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

Open Energy Info (EERE)

estimated visually. Waters sampled for chemical analysis were stored in brimful polyethylene bottles with Polyseal caps following filtration from a large syringe attached to a...

67

Isotopic Analysis- Fluid At Valles Caldera - Sulphur Springs...  

Open Energy Info (EERE)

estimated visually. Waters sampled for chemical analysis were stored in brimful polyethylene bottles with Polyseal caps following filtration from a large syringe attached to a...

68

ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.  

SciTech Connect (OSTI)

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

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

2000-12-01T23:59:59.000Z

69

ARM - Measurement - Isotope ratio  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Related InformationAciddropletgovMeasurementsIsotope ratio ARM

70

Laser isotope separation of erbium and other isotopes  

DOE Patents [OSTI]

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

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

1995-01-01T23:59:59.000Z

71

Standard test method for isotopic abundance analysis of uranium hexa?uoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry  

E-Print Network [OSTI]

Standard test method for isotopic abundance analysis of uranium hexa?uoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry

American Society for Testing and Materials. Philadelphia

2008-01-01T23:59:59.000Z

72

Water isotopes and the general circulation  

E-Print Network [OSTI]

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

Noone, David

73

RADIOCHEMICAL STUDIES OF NEUTRON DEFICIENT ACTINIDE ISOTOPES  

E-Print Network [OSTI]

Isotope Targets and Foils, AERE-R 5097, Paper 10 (1965). V.Isotope Targets and Foils, AERE-R 5097 Paper 12 (1965). K.M.Isotope Targets and Foils, AERE-R-5097 Paper 11 (1965). M.

Williams, Kimberly Eve

2011-01-01T23:59:59.000Z

74

Comparison of atmospheric hydrology over convective continental regions using water vapor isotope measurements from space  

E-Print Network [OSTI]

. Correlation analysis shows that mixing with boundary layer air, enhanced isotopic fractionation during precipitation, and subsiding air parcels contribute to intraseasonal isotopic variability. These local controls distillation in a Lagrangrian framework underestimates the observed isotopic depletion during the monsoons

75

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

76

Stable Isotope Analysis of a Middle Woodland Population from North Central Kansas  

E-Print Network [OSTI]

; Kortschak et al. 1965; Thomas 1951) and their corresponding stable isotope value ranges (Craig 1953; Sackett and Thompson 1963; Wickman 1952). Following this discovery, Hall (1967) first recognized that high carbon isotope values in maize and other grasses... would have been around -5‰ to -6‰; slightly higher without the contribution of carbon from fossil fuels. Today’s value is approximately -7‰ (Keeling 1961; Bada et al 1990; Marino and McElroy 1991; Schoeninger and Moore 1992). Malainey (2011:178) places...

Kauffman, Greg

2013-08-31T23:59:59.000Z

77

An informatics based analysis of the impact of isotope substitution on phonon modes in graphene  

SciTech Connect (OSTI)

It is shown by informatics that the high frequency short ranged modes exert a significant influence in impeding thermal transport through isotope substituted graphene nanoribbons. Using eigenvalue decomposition methods, we have extracted features in the phonon density of states spectra that reveal correlations between isotope substitution and phonon modes. This study also provides a data driven computational framework for the linking of materials chemistry and transport properties in 2D systems.

Broderick, Scott; Srinivasan, Srikant; Rajan, Krishna [Department of Material Science and Engineering, Iowa State University, Ames, Iowa 50011 (United States); Ray, Upamanyu; Balasubramanian, Ganesh, E-mail: bganesh@iastate.edu [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)

2014-06-16T23:59:59.000Z

78

Isotopic Trends in Production of Superheavies  

SciTech Connect (OSTI)

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

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

2005-11-21T23:59:59.000Z

79

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

80

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

SciTech Connect (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

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Isotope separation by laser means  

DOE Patents [OSTI]

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

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

1982-06-15T23:59:59.000Z

82

Deterioration of plutonium isotopic analysis with neurtron damage to HPGe detectors  

SciTech Connect (OSTI)

The effects of neutron (n) damage on HPGe detectors used to measure Pu isotopic ratios were investigated. Both a p-type planar and an n-type coaxial detector were progressively neutron damaged up to a total integrated flux of >5{times}10{sup 9} n/cm{sup 2} from a {sup 252}Cf source. Severe deterioration of selected peak shapes and degradation in the Pu isotopic analysis capability were observed and quantified by using the GRPANL and MGA codes developed at LLNL. After an integrated exposure of 1{times}10{sup 9} n/cm{sup 2} the Pu spectrum from the coaxial detector could not be analyzed with MGA. The planar detector spectrum continued to be analyzable with MGA up to 4{times}10{sup 9} n/cm{sup 2}. Cooling the planar detector to 80 K with an electrically-cooled cryostat could extent its useful lifetime up to an exposure of 2{times}10{sup 10} n/cm{sup 2}. 11 refs., 7 figs. , 1 tab.

Koenig, Z.M.; Gunnink, R.; Ruhter, W.D.; Camp, D.C.

1991-09-01T23:59:59.000Z

83

Method for laser induced isotope enrichment  

DOE Patents [OSTI]

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

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

2004-09-07T23:59:59.000Z

84

Apparatus and process for separating hydrogen isotopes  

DOE Patents [OSTI]

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

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

2013-06-25T23:59:59.000Z

85

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

E-Print Network [OSTI]

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

Mcdonough, William F.

86

Compelling Research Opportunities using Isotopes  

SciTech Connect (OSTI)

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

87

Novel hybrid isotope separation scheme and apparatus  

DOE Patents [OSTI]

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

Maya, J.

1991-06-18T23:59:59.000Z

88

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

89

Physics with isotopically controlled semiconductors  

SciTech Connect (OSTI)

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

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

2010-07-15T23:59:59.000Z

90

/, _(_ ,. 2:1 SIMS CHEMICAL AND ISOTOPIC ANALYSIS OF IMPACT FEATURES  

E-Print Network [OSTI]

impacts based on the chemical composition of projectile residues. The same measurement technique has now the origins of projectiles that left deposits too thin to be analyzed by conventional energy-dispersive x of impact deposits on a variety of sample surfaces. SIMS was also used to determine the isotopic

91

Isotope production facility produces cancer-fighting actinium  

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

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

92

A system analysis computer model for the High Flux Isotope Reactor (HFIRSYS Version 1)  

SciTech Connect (OSTI)

A system transient analysis computer model (HFIRSYS) has been developed for analysis of small break loss of coolant accidents (LOCA) and operational transients. The computer model is based on the Advanced Continuous Simulation Language (ACSL) that produces the FORTRAN code automatically and that provides integration routines such as the Gear`s stiff algorithm as well as enabling users with numerous practical tools for generating Eigen values, and providing debug outputs and graphics capabilities, etc. The HFIRSYS computer code is structured in the form of the Modular Modeling System (MMS) code. Component modules from MMS and in-house developed modules were both used to configure HFIRSYS. A description of the High Flux Isotope Reactor, theoretical bases for the modeled components of the system, and the verification and validation efforts are reported. The computer model performs satisfactorily including cases in which effects of structural elasticity on the system pressure is significant; however, its capabilities are limited to single phase flow. Because of the modular structure, the new component models from the Modular Modeling System can easily be added to HFIRSYS for analyzing their effects on system`s behavior. The computer model is a versatile tool for studying various system transients. The intent of this report is not to be a users manual, but to provide theoretical bases and basic information about the computer model and the reactor.

Sozer, M.C.

1992-04-01T23:59:59.000Z

93

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

E-Print Network [OSTI]

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

American Society for Testing and Materials. Philadelphia

2011-01-01T23:59:59.000Z

94

Isotopic Analysis- Fluid At Dixie Valley Geothermal Area (Kennedy & Soest,  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429 Throttled (botOpen Energy2005) | Open Energy Information Isotopic

95

Isotopic Analysis- Fluid At Fenton Hill HDR Geothermal Area (Goff & Janik,  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429 Throttled (botOpen Energy2005) | Open Energy Information Isotopic2002) |

96

Isotopic Analysis- Fluid At Fenton Hill HDR Geothermal Area (Goff, Et Al.,  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429 Throttled (botOpen Energy2005) | Open Energy Information Isotopic2002)

97

Isotopic Analysis- Fluid At Fenton Hill HDR Geothermal Area (Grigsby, Et  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to:46 - 429 Throttled (botOpen Energy2005) | Open Energy Information Isotopic2002)Al.,

98

Analysis of the ecology of Anchialine Caves using carbon and nitrogen stable isotopes  

E-Print Network [OSTI]

more than I could ever list here. If you have ever been there with me during one of those moments of discovery, you have made my life more special. Thank you. Without a good foundation, a fire, no matter how brilliant, flashes and fades... . . . . . . . . . . . . . . . . . . . , . . . . . . 4 9 12 13 14 15 16 19 21 MOTIVATION FOR RESEARCH . Characterize a Novel Ecosystem . . New Application for Stable Isotopes in Ecology . . . . . Access an Environmentally Sensitive Resource . 23 23 24 STUDY SITE. 26 Mayan Blue Cenote...

Pohlman, John William

1995-01-01T23:59:59.000Z

99

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

100

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

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

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

102

Telling friends from foes : strontium isotope and trace element analysis of companion burials from Pusilhá, Toledo District, Belize  

E-Print Network [OSTI]

Local Variability in Strontium Isotope Ratios of Human ToothDifferential Diagenesis of Strontium in Archaeological HumanThe ratio of barium to strontium as a paleodietary indicator

Somerville, Andrew D.

2010-01-01T23:59:59.000Z

103

Identification of isotopically primitive interplanetary dust particles: A NanoSIMS isotopic imaging study  

E-Print Network [OSTI]

Identification of isotopically primitive interplanetary dust particles: A NanoSIMS isotopic imaging contain larger regions with more modest enrichments in 15 N, leading to average bulk N isotopic of those IDPs that have anomalous bulk N isotopic compositions. These particles typically also contain

104

Spinelolivine magnesium isotope thermometry in the mantle and implications for the Mg isotopic composition of Earth  

E-Print Network [OSTI]

Spinel­olivine magnesium isotope thermometry in the mantle and implications for the Mg isotopic: magnesium isotopes mantle geochemistry meteorites MC-ICPMS The magnesium isotopic composition of Earth., 2004; Poitrasson et al., 2005; Georg et al., 2007; Poitrasson, 2007; Weyer et al., 2007). Magnesium

Manning, Craig

105

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

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

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

106

Isotope-labeled immunoassays without radiation waste  

E-Print Network [OSTI]

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

Hammock, Bruce D.

107

Isotope Cancer Treatment Research at LANL  

ScienceCinema (OSTI)

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

Weidner, John; Nortier, Meiring

2014-06-02T23:59:59.000Z

108

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

E-Print Network [OSTI]

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

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

109

The experimental and theoretical determination of combinatorial kinetic isotope effects for mechanistic analysis  

E-Print Network [OSTI]

in the ZPE of the reacting isotopomers as a reaction proceeds from starting material to the transition state ....................................................................... 3 1-2 Illustrates the relationship between the isotopic ratio, R/R 0... on the vibrational frequencies. k m ? = 1 2? (1-4) The quantum-mechanical treatment of the frequencies for the vibrational modes leads to the energy, E, in eq 1-5. (1-5) E = h?(n + 1/2) n = 0, 1, 2, ..... This energy is measured from the lowest...

Christian, Chad F.

2009-05-15T23:59:59.000Z

110

An isotopic analysis system for plutonium samples enriched in sup 238 Pu  

SciTech Connect (OSTI)

We have designed and built a gamma-ray spectrometer system that measures the relative plutonium isotopic abundances of plutonium oxide enriched in {sup 238}Pu. The first system installed at Westinghouse Savannah River Company was tested and evaluated on plutonium oxide in stainless steel EP60/61 containers. {sup 238}Pu enrichments ranged from 20% to 85%. Results show that 200 grams of plutonium oxide in an EP60.61 container can be measured with {plus minus}0.3% precision and better than {plus minus}1.0% accuracy in the specific power using a counting time of 50 minutes. 3 refs., 2 figs.

Ruhter, W.D.; Camp, D.C.

1991-08-01T23:59:59.000Z

111

Isotope hydrology of catchment basins: lithogenic and cosmogenic isotopic systems  

SciTech Connect (OSTI)

A variety of physical processes affect solute concentrations within catchment waters. The isotopic compositions of the solutes can indicate which processes have determined the observed concentrations. These processes together constitute the physical history of the water. Many solutes in natural waters are derived from the interaction between the water and the rock and/or soil within the system - these are termed `lithogenic` solutes. The isotopic compositions of these solutes provide information regarding rock-water interactions. Many other solutes have their isotopic compositions determined both within and outside of the catchment - i.e., in addition to being derived from catchment rock and soil, they are solutes that are also transported into the catchment. Important members of this group include solutes that have isotopic compositions produced by atomic particle interactions with other nuclides. The source of the atomic particles can be cosmic radiation (producing `cosmogenic` nuclides in the atmosphere and land surface), anthropogenic nuclear reactions (producing `thermonuclear` nuclides), or radioactive and fission decay of naturally-occurring elements, principally {sup 238}U (producing `in-situ` lithogenic nuclides in the deep subsurface). Current language usage often combines all of the atomic particle-produced nuclides under the heading `cosmogenic nuclides`, and for simplicity we will often follow that usage here, although always indicating which variety is being discussed. This paper addresses the processes that affect the lithogenic and cosmogenic solute concentrations in catchment waters, and how the isotopic compositions of the solutes can be used in integrative ways to identify these processes, thereby revealing the physical history of the water within a catchment system. The concept of a `system` is important in catchment hydrology. A catchment is the smallest landscape unit that can both participate in all of the aspects of the hydrologic cycle and also be treated as a mostly closed system for mass balance considerations. It is the near closure of the system that permits well- constrained chemical mass balance calculations to be made. These calculations generally focus of lithogenic solutes, and therefore in our discussions of lithogenic nuclides in the paper, the concept of chemical mass balance in a nearly dosed system will play an important role. Examination of the isotopic compositions of solutes provides a better understanding of the variety of processes controlling mass balance. It is with this approach that we examined the variety of processes occurring within the catchment system, such as weathering and soil production, generation of stormflow and streamflow (hydrograph separation), movement of soil pore water, groundwater flow, and the overall processes involved with basinal water balance. In this paper, the term `nuclide` will be used when referring to a nuclear species that contains a particular number of protons and neutrons. The term is not specific to any element. The term `isotope` will be used to distinguish nuclear species of a given element (atoms with the same number of protons). That is to say, there are many nuclides in nature - for example, {sup 36}Cl, {sup 87}Sr, {sup 238}U; the element has four naturally-occurring isotopes - {sup 87}Sr, and {sup 88}Sr. This paper will first discuss the general principles that underlie the study of lithogenic and cosmogenic nuclides in hydrology, and provide references to some of the more important studies applying these principles and nuclides. We then turn in the second section to a discussion of their specific applications in catchment- scale systems. The final section of this paper discusses new directions in the application of lithogenic and cosmogenic nuclides to catchment hydrology, with some thoughts concerning possible applications that still remain unexplored.

Nimz, G. J., LLNL

1998-06-01T23:59:59.000Z

112

Magnesium Isotopes in Halo Stars  

E-Print Network [OSTI]

We have determined Mg isotope ratios in halo field dwarfs and giants in the globular cluster M71 based on high S/N high spectral resolution (R = 10$^5$) Keck HIRES spectra. Unlike previous claims of an important contribution from intermediate-mass AGB stars to the Galactic halo, we find that our $^{26}$Mg/$^{24}$Mg ratios can be explained by massive stars.

Jorge Melendez; Judith G. Cohen

2007-08-29T23:59:59.000Z

113

Integration of Nontraditional Isotopic Systems Into Reaction...  

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

minerals in geothermal systems (feldspars, epidote, and calcite) often control fracture permeability changes. Measurements of Ca and Sr isotopic fractionation at high...

114

Integration of Nontraditional Isotopic Systems Into Reaction...  

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

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

115

Gamma Spectrum from Neutron Capture on Tungsten Isotopes  

E-Print Network [OSTI]

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

Hurst, Aaron

2011-01-01T23:59:59.000Z

116

Spatial periphery of lithium isotopes  

SciTech Connect (OSTI)

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

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

2013-12-15T23:59:59.000Z

117

Neutronic Analysis of an Advanced Fuel Design Concept for the High Flux Isotope Reactor  

SciTech Connect (OSTI)

This study presents the neutronic analysis of an advanced fuel design concept for the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) that could significantly extend the current fuel cycle length under the existing design and safety criteria. A key advantage of the fuel design herein proposed is that it would not require structural changes to the present HFIR core, in other words, maintaining the same rated power and fuel geometry (i.e., fuel plate thickness and coolant channel dimensions). Of particular practical importance, as well, is the fact that the proposed change could be justified within the bounds of the existing nuclear safety basis. The simulations herein reported employed transport theory-based and exposure-dependent eigenvalue characterization to help improve the prediction of key fuel cycle parameters. These parameters were estimated by coupling a benchmarked three-dimensional MCNP5 model of the HFIR core to the depletion code ORIGEN via the MONTEBURNS interface. The design of an advanced HFIR core with an improved fuel loading is an idea that evolved from early studies by R. D. Cheverton, formerly of ORNL. This study contrasts a modified and increased core loading of 12 kg of 235U against the current core loading of 9.4 kg. The simulations performed predict a cycle length of 39 days for the proposed fuel design, which represents a 50% increase in the cycle length in response to a 25% increase in fissile loading, with an average fuel burnup increase of {approx}23%. The results suggest that the excess reactivity can be controlled with the present design and arrangement of control elements throughout the core's life. Also, the new power distribution is comparable or even improved relative to the current power distribution, displaying lower peak to average fission rate densities across the inner fuel element's centerline and bottom cells. In fact, the fission rate density in the outer fuel element also decreased at these key locations for the proposed design. Overall, it is estimated that the advanced core design could increase the availability of the HFIR facility by {approx}50% and generate {approx}33% more neutrons annually, which is expected to yield sizeable savings during the remaining life of HFIR, currently expected to operate through 2014. This study emphasizes the neutronics evaluation of a new fuel design. Although a number of other performance parameters of the proposed design check favorably against the current design, and most of the core design features remain identical to the reference, it is acknowledged that additional evaluations would be required to fully justify the thermal-hydraulic and thermal-mechanical performance of a new fuel design, including checks for cladding corrosion performance as well as for industrial and economic feasibility.

Xoubi, Ned [ORNL; Primm, Trent [ORNL; Maldonado, G. Ivan [University of Tennessee, Knoxville (UTK)

2009-01-01T23:59:59.000Z

118

Modular Isotopic Thermoelectric Generator  

SciTech Connect (OSTI)

Advanced RTG concepts utilizing improved thermoelectric materials and converter concepts are under study at Fairchild for DOE. The design described here is based on DOE's newly developed radioisotope heat source, and on an improved silicon-germanium material and a multicouple converter module under development at Syncal. Fairchild's assignment was to combine the above into an attractive power system for use in space, and to assess the specific power and other attributes of that design. The resultant design is highly modular, consisting of standard RTG slices, each producing ~24 watts at the desired output voltage of 28 volt. Thus, the design could be adapted to various space missions over a wide range of power levels, with little or no redesign. Each RTG slice consists of a 250-watt heat source module, eight multicouple thermoelectric modules, and standard sections of insulator, housing, radiator fins, and electrical circuit. The design makes it possible to check each thermoelectric module for electrical performance, thermal contact, leaktightness, and performance stability, after the generator is fully assembled; and to replace any deficient modules without disassembling the generator or perturbing the others. The RTG end sections provide the spring-loaded supports required to hold the free-standing heat source stack together during launch vibration. Details analysis indicates that the design offers a substantial improvement in specific power over the present generator of RTGs, using the same heat source modules. There are three copies in the file.

Schock, Alfred

1981-04-03T23:59:59.000Z

119

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

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

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

120

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

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

Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor CRAD, Maintenance - Oak Ridge National Laboratory High Flux Isotope Reactor February 2007 A section of...

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

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

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

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

122

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

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

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

123

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

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

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...

124

Enriched Stable Isotope Materials and Chemistry | ornl.gov  

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

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

125

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

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

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

126

applied isotope techniques: Topics by E-print Network  

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

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

127

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

2012-01-17T23:59:59.000Z

128

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

129

Isotope separation by selective photodissociation of glyoxal  

DOE Patents [OSTI]

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

Marling, John B. (Pleasanton, CA)

1976-01-01T23:59:59.000Z

130

Advanced Mass Spectrometers for Hydrogen Isotope Analyses  

SciTech Connect (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

131

Isotope Production and Distribution Program`s Fiscal Year 1997 financial statement audit  

SciTech Connect (OSTI)

The Department of Energy Isotope Production and Distribution Program mission is to serve the national need for a reliable supply of isotope products and services for medicine, industry and research. The program produces and sells hundreds of stable and radioactive isotopes that are widely utilized by domestic and international customers. Isotopes are produced only where there is no U.S. private sector capability or other production capacity is insufficient to meet U.S. needs. The Department encourages private sector investment in new isotope production ventures and will sell or lease its existing facilities and inventories for commercial purposes. The Isotope Program reports to the Director of the Office of Nuclear Energy, Science and Technology. The Isotope Program operates under a revolving fund established by the Fiscal Year (FY) 1990 Energy and Water Appropriations Act and maintains financial viability by earning revenues from the sale of isotopes and services and through annual appropriations. The FY 1995 Energy and Water Appropriations Act modified predecessor acts to allow prices charged for Isotope Program products and services to be based on production costs, market value, the needs of the research community, and other factors. Although the Isotope Program functions as a business, prices set for small-volume, high-cost isotopes that are needed for research purposes may not achieve full-cost recovery. As a result, isotopes produced by the Isotope Program for research and development are priced to provide a reasonable return to the U.S. Government without discouraging their use. Commercial isotopes are sold on a cost-recovery basis. Because of its pricing structure, when selecting isotopes for production, the Isotope Program must constantly balance current isotope demand, market conditions, and societal benefits with its determination to operate at the lowest possible cost to U.S. taxpayers. Thus, this report provides a financial analysis of this situation.

NONE

1998-03-27T23:59:59.000Z

132

Analysis of Elemental and Isotopic Composition of a Substance Obtained in Experiments on Energy Concentration in a Solid-State Superdense Plasma  

E-Print Network [OSTI]

We present the results of the experimental study on synthesis of a wide range of isotopes in a superdense plasma. The initial conditions necessary for plasma bunch formation were provided by specially organized coherent impact on a solid target with a total energy up to 1 kJ. More than 4000 shots were performed with various targets made of light, medium, and heavy elements. Subsequent analysis of the products of the target explosion reveals the presence of a wide range of elements absent in the initial materials. Elements with nuclei three and more times heavier than the nucleus of the target main element are detected in the products. The isotopic composition of the produced elements significantly differs from the natural one. The presence of unknown superheavy elements at the border of the periodic table and beyond it was detected by several different spectroscopic methods of elemental and isotopic analyzes.

S. V. Adamenko; A. S. Adamenko

2003-04-23T23:59:59.000Z

133

Isotopes  

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

are saving lives, advancing cutting-edge research and keeping the U.S. safe. Strontium-82 produced at Los Alamos is used in hospitals nation- and world-wide for critical...

134

ISOTOPES  

E-Print Network [OSTI]

1955). Production of Heavy water, 37. G.M. Keyser, D.B.Economy of Production of Heavy Water, Turin, Italy (1970),world production of heavy water to ~1ay, 1977. From data

Lederer, C. Michael

2013-01-01T23:59:59.000Z

135

ISOTOPES  

E-Print Network [OSTI]

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

136

Isotopes  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/SurfacePump-Testing Sign

137

ISOTOPES  

E-Print Network [OSTI]

5-7. 1975, British Nuclear Engineering Society (1975). 87.London, March British Nuclear Engineering Society (1975).T.H. Pigford, Nuclear Chemical Engineering (1St edition),

Lederer, C. Michael

2013-01-01T23:59:59.000Z

138

Atomic vapor laser isotope separation of lead-210 isotope  

DOE Patents [OSTI]

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

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

1999-01-01T23:59:59.000Z

139

Atomic vapor laser isotope separation of lead-210 isotope  

DOE Patents [OSTI]

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

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

1999-08-31T23:59:59.000Z

140

Reactor physics input to the safety analysis report for the High Flux Isotope Reactor  

SciTech Connect (OSTI)

HFIR specific, few group neutron and coupled neutron-gamma libraries have been prepared. These are based on data from ENDF/B-V and beginning-of-life (BOL) conditions. The neutron library includes actinide data for curium target rods. Six critical experiments, collectively designated HFIR critical experiment 4, were analyzed. Calculated k-effective was 2% high at BOL-typical conditions but was 1.0 at end-of-life-typical conditions. The local power density distributions were calculated for each of the critical experiments. The axially averaged values at a given radius were frequently within experimental error. However at individual points, the calculated local power densities were significantly different from the experimentally derived values (several times greater than experimental uncertainty). A reassessment of the foil activation data with transport theory techniques seems desirable. Using the results of the critical experiments study, a model of current HFIR configuration was prepared. As with the critical experiments, BOL k-effective was high (3%). However, end-of-life k-effective was high (2%). The end-of-life concentrations of fission products were compared to those generated using the ORIGEN code. Agreement was generally good through differences in the inventories of some important nuclides, Xe and I, need to be understood. End-of-cycle curium target isotopics based on measured, discharged target rods were compared to calculated values and agreement was good. Axial flux plots at various irradiation positions were generated. Time-dependent power distributions based on two-dimensional calculations were provided.

Primm, R.T. III.

1992-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Ca isotopic anomaly in the atmospheres of Ap stars  

E-Print Network [OSTI]

We present results of the Ca stratification analysis in the atmospheres of 21 magnetic chemically peculiar (Ap) stars. This analysis was based on the spectral observations carried out with the UVES spectrograph attached to the 8-m VLT telescope. Ca was found to be strongly stratified in all stars with different effective temperatures and magnetic field strengths. This element is overabundant by 1-1.5 dex below logtau_5000~-1 and strongly depleted above logtau_5000=-1.5. Based on the overall Ca abundance distributions, we modelled a profile of the IR-triplet Ca II 8498 line. It shows a significant contribution of the heavy isotopes 46Ca and 48Ca, which represent less than 1% of the solar Ca isotopic mixture. In Ap stars with the relatively small surface magnetic fields (Ca isotope is concentrated close to the photosphere, while the heavy isotopes are pushed towards the outer layers. Isotopic separation disappears in the atmospheres of stars with magnetic fields above 6-7 kG. The observed overall Ca stratification and isotopic anomalies may be explained by a combined action of the radiatively-driven diffusion and the light-induced drift.

T. Ryabchikova; O. Kochukhov; S. Bagnulo

2007-03-13T23:59:59.000Z

142

Theory of the helium isotope shift  

E-Print Network [OSTI]

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

Yerokhin, Vladimir A

2015-01-01T23:59:59.000Z

143

USACE FUSRAP Maywood Team Identifies Challenges and Initiates Alternate Solutions Relating to the Radiochemical Analysis of Borosilicate Fiber Filters for Isotopes of Uranium and Thorium  

SciTech Connect (OSTI)

This presentation discusses the primary purposes of particulate radionuclide air monitoring at the US Army Corps of Engineers (USACE) Formerly Utilized Sites Remediation Program (FUSRAP) Maywood Superfund Site (FMSS), the challenges encountered by the team when standard radiochemistry analytical methods are attempted on borosilicate fiber filter samples, the surrogate evaluations used when sample specific isotopic analysis is unsuccessful, and current strategies for overcoming radiochemistry method deficiencies. Typical borosilicate fiber filter sample preparation procedures including tracer spike and digestion methods and their impact on uranium and thorium data quality are of particular interest. Analytes discussed include isotopic uranium (U-234, U-235, and U-238) and isotopic thorium (Th-228, Th-230, and Th-232). Efforts to obtain reproducible and defensible results also included discussions with commercial laboratory radiochemistry managers as well as industry experts. This presentation may benefit sites that use similar sample collection and analysis techniques, utilize data that may have unidentified method-related issues with diminished data quality, or have a similar isotopic signature. (authors)

Tucker, B. [Shaw Environmental and Infrastructure, Salem, NH (United States); Winters, M. [Shaw Environmental and Infrastructure, Maywood, NJ (United States); Hays, D. [Unites States Army Corps of Engineers, Maywood, NJ (United States)

2008-07-01T23:59:59.000Z

144

Nonequilibrium clumped isotope signals in microbial methane  

E-Print Network [OSTI]

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

Wang, David T.

145

A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER  

E-Print Network [OSTI]

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

O'Donnell, Tom

146

Precise ruthenium fission product isotopic analysis using dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS)  

SciTech Connect (OSTI)

99Tc is a subsurface contaminant of interest at numerous federal, industrial, and international facilities. However, as a mono-isotopic fission product, 99Tc lacks the ability to be used as a signature to differentiate between the different waste disposal pathways that could have contributed to subsurface contamination at these facilities. Ruthenium fission-product isotopes are attractive analogues for the characterization of 99Tc sources because of their direct similarity to technetium with regard to subsurface mobility, and their large fission yields and low natural background concentrations. We developed an inductively coupled plasma mass spectrometry (ICP-MS) method capable of measuring ruthenium isotopes in groundwater samples and extracts of vadose zone sediments. Samples were analyzed directly on a Perkin Elmer ELAN DRC II ICP-MS after a single pass through a 1-ml bed volume of Dowex AG 50W-X8 100-200 mesh cation exchange resin. Precise ruthenium isotopic ratio measurements were achieved using a low-flow Meinhard-type nebulizer and long sample acquisition times (150,000 ms). Relative standard deviations of triplicate replicates were maintained at less than 0.5% when the total ruthenium solution concentration was 0.1 ng/ml or higher. Further work was performed to minimize the impact caused by mass interferences using the dynamic reaction cell (DRC) with O2 as the reaction gas. The aqueous concentrations of 96Mo and 96Zr were reduced by more than 99.7% in the reaction cell prior to injection of the sample into the mass analyzer quadrupole. The DRC was used in combination with stable-mass correction to quantitatively analyze samples containing up to 2-orders of magnitude more zirconium and molybdenum than ruthenium. The analytical approach documented herein provides an efficient and cost-effective way to precisely measure ruthenium isotopes and quantitate total ruthenium (natural vs. fission-product) in aqueous matrixes.

Brown, Christopher F.; Dresel, P. Evan; Geiszler, Keith N.; Farmer, Orville T.

2006-05-09T23:59:59.000Z

147

The Oxygen core inside the Magnesium isotopes  

E-Print Network [OSTI]

We have studied the ground state bulk properties of magnesium isotopes using axially symmetric relativistic mean field formalism. The BCS pairing approach is employed to take care of the pairing correlation for the open shell nuclei. The contour plot of the nucleons distribution are analyzed at various parts of the nucleus, where clusters are located. The presence of an $^{16}$O core along bubble like $\\alpha$-particle(s) and few {\\it nucleons} are found in the Mg isotopes.

Bhuyan, M

2013-01-01T23:59:59.000Z

148

Mechanistic studies using kinetic isotope effects  

E-Print Network [OSTI]

MECHANISTIC STUDIES USING KINETIC ISOTOPE EFFECTS A Thesis by BRIAN E. SCHULMFIER Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requtrements for the degree of MASTER OF SCIENCE December... 1999 Major Subject: Chemistry MECHANISTIC STUDIES USING KINETIC ISOTOPE EFFECTS A Thesis by BRIAN E. SCHULMEIER Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved...

Schulmeier, Brian E.

2012-06-07T23:59:59.000Z

149

Strontium and carbon isotope stratigraphy of the Llandovery (Early Silurian): Implications for tectonics and weathering  

E-Print Network [OSTI]

Strontium and carbon isotope stratigraphy of the Llandovery (Early Silurian): Implications online 2 June 2010 Keywords: Silurian Strontium isotopes Carbon isotopes Weathering K-bentonites A high

Saltzman, Matthew R.

150

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

E-Print Network [OSTI]

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

Chakraborty, Subrata

2013-01-01T23:59:59.000Z

151

Isotopic Composition of Solar Wind Calcium: First in Situ Measurement by CELIAS/MTOF on Board SOHO  

E-Print Network [OSTI]

We present first results on the Ca isotopic abundances derived from the high resolution Mass Time-of-Flight (MTOF) spectrometer of the charge, element, and isotope analysis system (CELIAS) experiment on board the Solar and Heliospheric Observatory (SOHO). We obtain isotopic ratios 40Ca/42Ca = (128+-47) and 40Ca/44Ca = (50+-8), consistent with terrestrial values. This is the first in situ determination of the solar wind calcium isotopic composition and is important for studies of stellar modeling and solar system formation since the present-day solar Ca isotopic abundances are unchanged from their original isotopic composition in the solar nebula.

R. Kallenbach; F. M. Ipavich; P. Bochsler; S. Hefti; P. Wurz; M. R. Aellig; A. B. Galvin; J. Geiss; F. Gliem; G. Gloeckler; H. Grunwaldt; M. Hilchenbach; D. Hovestadt; B. Klecker

1998-02-07T23:59:59.000Z

152

Isotope shift in the sulfur electron affinity: Observation and theory  

SciTech Connect (OSTI)

The sulfur electron affinities {sup e}A(S) are measured by photodetachment microscopy for the two isotopes {sup 32}S and {sup 34}S (16 752.975 3(41) and 16 752.977 6(85) cm{sup -1}, respectively). The isotope shift in the electron affinity is found to be more probably positive, {sup e}A({sup 34}S)- {sup e}A({sup 32}S) =+0.0023(70) cm{sup -1}, but the uncertainty allows for the possibility that it may be either ''normal''[{sup e}A({sup 34}S) > {sup e}A({sup 32}S)] or ''anomalous''[{sup e}A({sup 34}S) < {sup e}A({sup 32}S)]. The isotope shift is estimated theoretically using elaborate correlation models, monitoring the electron affinity and the mass polarization term expectation value. The theoretical analysis predicts a very large specific mass shift (SMS) that counterbalances the normal mass shift (NMS) and produces an anomalous isotope shift {sup e}A({sup 34}S)- {sup e}A({sup 32}S) =-0.0053(24) cm{sup -1}, field shift corrections included. The total isotope shift can always be written as the sum of the NMS (here +0.0169 cm{sup -1}) and a residual isotope shift (RIS). Since the NMS has nearly no uncertainty, the comparison between experimental and theoretical RIS is more fair. With respective values of -0.0146(70) cm{sup -1} and -0.0222(24) cm{sup -1}, these residual isotope shifts are found to agree within the estimated uncertainties.

Carette, Thomas; Scharf, Oliver; Godefroid, Michel [Chimie Quantique et Photophysique, Universite Libre de Bruxelles - CP160/09, B-1050 Brussels (Belgium); Drag, Cyril; Blondel, Christophe; Delsart, Christian [Laboratoire Aime-Cotton, CNRS, Universite Paris-sud, F-91405 Orsay cedex (France); Froese Fischer, Charlotte [National Institute of Standards and Technology Gaithersburg, Maryland 20899-8420 (United States)

2010-04-15T23:59:59.000Z

153

International Workshop on Gamma Spectrometry Analysis Codes for U and Pu Isotopics: Workshop Results and Next Steps  

SciTech Connect (OSTI)

In November 2008, the Institute of Nuclear Materials Management (INMM) and the European Safeguards Research and Development Association (ESARDA) co-hosted the International Workshop on Gamma Spectrometry Analysis Codes for U and Pu Isotopics at the Oak Ridge National Laboratory (ORNL). This workshop was conducted in response to needs expressed by the international safeguards community to understand better the capabilities and limitations of the codes; to ensure these codes are sustained; and to ensure updates or revisions are performed in a controlled manner. The workshop was attended by approximately 100 participants. The participants included code developers, code suppliers, safeguards specialists, domestic and international inspectors, process operators, regulators, and programme sponsors from various government agencies. The workshop provided a unique opportunity for code developers, commercial distributors and end users to interact in a hands-on laboratory environment to develop solutions for programmatic and technical issues associated with the various codes. The workshop also provided an international forum for discussing development of an internationally accepted standard test method. This paper discusses the organization of the workshop, its goals and objectives and feedback received from the participants. The paper also describes the significance of the working group's contribution to improving codes that are commonly used during inspections to verify that nuclear facilities are compliant with treaty obligations that ensure nuclear fuel cycle facilities are used for peaceful purposes.

McGinnis, Brent R [ORNL; Solodov, Alexander A [ORNL; Shipwash, Jacqueline L [ORNL; Zhernosek, Alena V [ORNL; McKinney, Teressa L [ORNL; Pickett, Chris A [ORNL; Peerani, Paolo [ORNL

2009-01-01T23:59:59.000Z

154

Standard test method for isotopic analysis of hydrolyzed uranium hexafluoride and uranyl nitrate solutions by thermal ionization mass spectrometry  

E-Print Network [OSTI]

1.1 This method applies to the determination of isotopic composition in hydrolyzed nuclear grade uranium hexafluoride. It covers isotopic abundance of 235U between 0.1 and 5.0 % mass fraction, abundance of 234U between 0.0055 and 0.05 % mass fraction, and abundance of 236U between 0.0003 and 0.5 % mass fraction. This test method may be applicable to other isotopic abundance providing that corresponding standards are available. 1.2 This test method can apply to uranyl nitrate solutions. This can be achieved either by transforming the uranyl nitrate solution to a uranyl fluoride solution prior to the deposition on the filaments or directly by depositing the uranyl nitrate solution on the filaments. In the latter case, a calibration with uranyl nitrate standards must be performed. 1.3 This test method can also apply to other nuclear grade matrices (for example, uranium oxides) by providing a chemical transformation to uranyl fluoride or uranyl nitrate solution. 1.4 This standard does not purport to address al...

American Society for Testing and Materials. Philadelphia

2005-01-01T23:59:59.000Z

155

Laser Isotope Separation Employing Condensation Repression  

SciTech Connect (OSTI)

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

156

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

157

Fragment Isotope Distributions and the Isospin Dependent Equation of State  

E-Print Network [OSTI]

Calculations predict a connection between the isotopic composition of particles emitted during an energetic nucleus-nucleus collision and the density dependence of the asymmetry term of the nuclear equation of state (EOS). This connection is investigated for central 112Sn+112Sn and 124Sn+124Sn collisions at E/A=50 MeV in the limit of an equilibrated freezeout condition. Comparisons between measured isotopic yields ratios and theoretical predictions in the equilibrium limit are used to assess the sensitivity to the density dependence of the asymmetry term of the EOS. This analysis suggests that such comparisons may provide an opportunity to constrain the asymmetry term of the EOS.

W. P. Tan; B-A. Li; R. Donangelo; C. K. Gelbke; M-J. van Goetherm; X. D. Liu; W. G. Lynch; S. Souza; M. B. Tsang; G. Verde; A. Wagner; N. S. Xu

2001-04-21T23:59:59.000Z

158

Method for production of an isotopically enriched compound  

DOE Patents [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

159

Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui  

E-Print Network [OSTI]

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

160

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]. 8 figs.

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

1987-04-07T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

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

162

Isotope Research Materials Laboratory | ornl.gov  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/SurfacePump-Testing Sign InIsotope ProgramIsotope

163

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

SciTech Connect (OSTI)

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

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

2013-09-15T23:59:59.000Z

164

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

SciTech Connect (OSTI)

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

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

2013-01-15T23:59:59.000Z

165

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

SciTech Connect (OSTI)

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

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

2013-09-15T23:59:59.000Z

166

Discovery of samarium, europium, gadolinium, and terbium isotopes  

SciTech Connect (OSTI)

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

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

2013-01-15T23:59:59.000Z

167

Discovery of Rubidium, Strontium, Molybdenum, and Rhodium Isotopes  

E-Print Network [OSTI]

Currently, thirty-one rubidium, thirty-five strontium, thirty-five molybdenum and thirty-eight rhodium 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.

Parker, A M

2011-01-01T23:59:59.000Z

168

Discovery of rubidium, strontium, molybdenum, and rhodium isotopes  

SciTech Connect (OSTI)

Currently, 31 rubidium, 35 strontium, 35 molybdenum, and 38 rhodium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

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

2012-07-15T23:59:59.000Z

169

Discovery of Rubidium, Strontium, Molybdenum, and Rhodium Isotopes  

E-Print Network [OSTI]

Currently, thirty-one rubidium, thirty-five strontium, thirty-five molybdenum and thirty-eight rhodium 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.

A. M. Parker; M. Thoennessen

2011-02-11T23:59:59.000Z

170

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

E-Print Network [OSTI]

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

C. Fry; M. Thoennessen

2012-03-06T23:59:59.000Z

171

Discovery of Chromium, Manganese, Nickel, and Copper Isotopes  

E-Print Network [OSTI]

Twenty-seven chromium, twenty-five manganese, thirty-one nickel and twenty-six copper isotopes have so far been observed and the discovery of these isotopes is discussed. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

K. Garofali; R. Robinson; M. Thoennessen

2010-12-07T23:59:59.000Z

172

Discovery of Cesium, Lanthanum, Praseodymium and Promethium Isotopes  

E-Print Network [OSTI]

Currently, forty-one cesium, thirty-five lanthanum, thirty-two praseodymium, and thirty-one promethium, 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.

May, E

2011-01-01T23:59:59.000Z

173

Discovery of Cesium, Lanthanum, Praseodymium and Promethium Isotopes  

E-Print Network [OSTI]

Currently, forty-one cesium, thirty-five lanthanum, thirty-two praseodymium, and thirty-one promethium, 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.

E. May; M. Thoennessen

2011-09-08T23:59:59.000Z

174

Hydrogen isotope fractionation during lipid biosynthesis by Tetrahymena thermophila  

E-Print Network [OSTI]

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

175

Effect of Alumina and Titania on the Oxidation of CO over Au Nanoparticles Evaluted by 13C Isotopic Transient Analysis  

SciTech Connect (OSTI)

Titania- and alumina-supported Au nanoparticles were synthesized by a deposition-precipitation method and subsequent thermal treatment in He. X-ray absorption spectroscopy at the Au-L{sub III} edge revealed that the as-prepared Au/TiO{sub 2} sample contained cationic Au that was reduced to a predominately metallic state after treatment in He at 623 K. Scanning transmission electron microscopy showed the Au to be highly dispersed over both the metal oxides, with an average particle size of 3.3 nm for Au/TiO{sub 2} and 2.5 nm for Au/Al{sub 2}O{sub 3}. The global rate, apparent activation energy, and orders of reaction with respect to CO and O{sub 2} of CO oxidation were different for the two metal oxide-supported samples. Steady-state isotopic transient kinetic analysis was used to explore the intrinsic turnover frequency (TOF{sub intr}) and coverage of active carbon-containing intermediates ({theta}{sub COx}) that led to carbon dioxide during CO oxidation. After correcting for CO{sub 2} readsorption, the TOF{sub intr} was found to be independent of temperature, approximately 3.4 s{sup -1} for Au/TiO{sub 2} (261-303 K) and 2.1 s{sup -1} for Au/Al{sub 2}O{sub 3} (272-343 K). At 293 K, the coverage of active carbon-containing intermediates was greater over Au/TiO{sub 2} than over Au/Al{sub 2}O{sub 3}. The higher coverage of species-forming product on Au/TiO{sub 2} is attributed to the greater availability of active surface oxygen on a titania catalyst compared with an alumina catalyst.

Calla,J.; Bore, M.; Datye, A.; Davis, R.

2006-01-01T23:59:59.000Z

176

GUM Analysis for TIMS Isotopic Ratios in BEP0 Graphite Qualification Samples, Round 2  

SciTech Connect (OSTI)

In May 2007, one set of three samples from NBL were addressed to Steve Petersen for TIMS analysis, and included BEP0 samples numbered 27008, 30986, and 50846. All cores were trimmed by tooling, and lightly cleaned by CO2 pellet blasting. Small discs were cut from the second set of samples for SIMS analysis, with the remainder of each used for TIMS preparation.

Gerlach, David C.; Heasler, Patrick G.; Reid, Bruce D.

2009-01-01T23:59:59.000Z

177

Strontium isotopic variations of Neoproterozoic seawater: Implications for crustal evolution  

SciTech Connect (OSTI)

The authors report high precision Sr isotopic data on carbonates from the Neoproterozoic Shaler Group, Victoria Island, Northwest Territories, Canada. Samples with low {sup 87}Rb/{sup 86}Sr ratios (<0.01) were selected for Sr isotopic analysis. {delta}{sup 18}O, Mn, Ca, Mg, and Sr data were used to recognize altered samples. The altered samples are characterized by high Mn/Sr ({ge}2) and variable {delta}{sup 18}O; most are dolomites. The data indicate that between ca. 790-850 Ma the {sup 87}Sr/{sup 86}Sr ratio of seawater varied between 0.70676 and 0.70561. The samples show smooth and systematic variation, with the lowest {sup 87}Sr/{sup 86}Sr value of 0.70561 at ca. 830 Ma. The low {sup 87}Sr/{sup 86}Sr ratio of carbonates from the lower parts of the section is similar to a value reported for one sample from the Adrar of Mauritania ({approx}900 Ma), West African Craton. Isotopic ratios from the upper part of the Shaler section are identical to values from the lower part of the Neoproterozoic Akademikerbreen Group, Spitsbergen. Although a paucity of absolute age determinations hinders attempts at the precise correlation of Neoproterozoic successions, it is possible to draw a broad outline of the Sr isotopic composition of seawater for this period. Data from this study and the literature are used to construct a curve of the {sup 87}Sr/{sup 86}Sr ratio of Neoproterozoic seawater. The Sr isotope composition of seawater reflects primarily the balance between continental Sr input through river input and mantle input via hydrothermal circulation of seawater through mid-ocean ridges. Coupling of Nd and Sr isotopic systems allows the authors to model changes in seafloor spreading rates (or hydrothermal flux) and continental erosion. The Sr hydrothermal flux and the erosion rate (relative to present-day value) are modeled for the period 500-900 Ma.

Asmerom, Y.; Jacobsen, S.B.; Knoll, A.H.; Butterfield, N.J. (Harvard Univ., Cambridge, MA (United States)); Swett, K. (Univ. of Iowa, Iowa City (United States))

1991-10-01T23:59:59.000Z

178

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

E-Print Network [OSTI]

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

Sturm, Christophe "Kristof"

179

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

SciTech Connect (OSTI)

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

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

1988-01-01T23:59:59.000Z

180

Radiation Sources External Beam and Isotopes  

E-Print Network [OSTI]

Radiation Sources External Beam and Isotopes J. Daniel Bourland, PhD Professor Department of Radiation Oncology Departments of Physics and Biomedical Engineering Wake Forest School of Medicine Winston Radiation · Photons: electromagnetic radiation, no mass, E = h · X rays: origins are from atomic energy

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Review of hydrogen isotope permeability through materials  

SciTech Connect (OSTI)

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

Steward, S.A.

1983-08-15T23:59:59.000Z

182

Trace Element and Isotopic Fluxes/ Subducted Slab  

E-Print Network [OSTI]

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

Bebout, Gray E.

183

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.hydrol-earth-syst-sci-discuss.net/5/547/2008/ © Author(s) 2008. This work is licensed under a Creative Commons License. Hydrology and Earth System Sciences Discussions Papers published in Hydrology and Earth System Sciences Discussions

Boyer, Edmond

184

Radioactive isotopes in Danish drinking water  

E-Print Network [OSTI]

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

185

Carbon IsotopesCarbon Isotopes A Short Course VU March, 2009  

E-Print Network [OSTI]

. Historical CO2 record from the Vostok ice core. In Trends: A Compendium of Data on Global Change. Carbon · Bitumen · Coal Range of Carbon Isotopes PDB Hoefs 1982 #12;2/25/2009 3 Range of Carbon Isotopes PDB Hoefs 1982 12CO2 Photosynthesis 12CO2 Respiration 13CO2 CO2+ RUBP = PGA (=27) RUBISCO #12;2/25/2009 4

Miami, University of

186

Method of enhancing selective isotope desorption from metals  

DOE Patents [OSTI]

A method of enhancing the thermal desorption of a first isotope of a diatomic gas from a metal comprises the steps of (a) establishing a partial pressure of a second isotope of the diatomic gas in vicinity of the metal; heating the metal to a temperature such that the first isotope is desorbed from the metal; and reducing the partial pressure of the desorbed first isotope while maintaining the partial pressure of the second isotope substantially constant. The method is especially useful for enhancing the desorption of tritium from the Zr-Al getter in a plasma confinement device.

Knize, Randall J. (Plainsboro, NJ); Cecchi, Joseph L. (Lawrenceville, NJ)

1984-01-01T23:59:59.000Z

187

Achievements in testing of the MGA and FRAM isotopic software codes under the DOE/NNSA-IRSN cooperation of gamma-ray isotopic measurement systems  

SciTech Connect (OSTI)

DOE/NNSA and IRSN collaborated on a study of gamma-ray instruments and analysis methods used to perform isotopic measurements of special nuclear materials. The two agencies agreed to collaborate on the project in response to inconsistencies that were found in the various versions of software and hardware used to determine the isotopic abundances of uranium and plutonium. IRSN used software developed internally to test the MGA and FRAM isotopic analysis codes for criteria used to stop data acquisition. The stop-criterion test revealed several unusual behaviors in both the MGA and FRAM software codes.

Vo, Duc [Los Alamos National Laboratory; Wang, Tzu - Fang [LLNL; Funk, Pierre [IRSN; Weber, Anne - Laure [IRSN; Pepin, Nicolas [IRSN; Karcher, Anna [IRSN

2009-01-01T23:59:59.000Z

188

SPECIAL FEATURE: ISOSCAPES Strontium isotopes in tap water from the coterminous USA  

E-Print Network [OSTI]

SPECIAL FEATURE: ISOSCAPES Strontium isotopes in tap water from the coterminous USA LESLEY A., B. J. Tipple, G. N. Mackey, S. A. Hynek, D. P. Fernandez, and J. R. Ehleringer. 2012. Strontium-00122.1 Abstract. Strontium isotope analysis has proven useful in geo-location investigations of organic

Tipple, Brett

189

U235: a gamma ray analysis code for uranium isotopic determination  

SciTech Connect (OSTI)

A {sup 235}U analysis code, U235, has been written that can nondestructively determine the percentage of {sup 235}U in a uranium sample from the analysis of the emitted gamma rays. The code is operational and work is now underway to improve the accuracy of the calculation, particularly at the high (>90%) and low (<0.7%) {sup 235}U concentrations. A technique has been found to evaluate low {sup 235}U concentrations that works well on the existing standards. Work is now under way to evaluate this technique for other detectors and other types of samples. Work is also proceeding on: (1) ways to better determine gamma backgrounds, (2) techniques to determine the equivalent thickness of the sample to correct for gamma attenuation, (3) evaluation of the existing data base of branching ratios of {sup 235}U, {sup 238}U and their daughters gamma rays to allow better results and (4) evaluation of the existing data base on the emission ratios for uranium, thorium, and protactinium x-rays.

Clark, D.

1997-12-01T23:59:59.000Z

190

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

191

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

192

Diffusional exchange of isotopes in a metal hydride sphere.  

SciTech Connect (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

193

Isotopic noble gas signatures released from medical isotope production facilities - Simulations and measurements  

SciTech Connect (OSTI)

Journal article on the role that radioxenon isotopes play in confirming whether or not an underground explosion was nuclear in nature. Radioxenon isotopes play a major role in confirming whether or not an underground explosion was nuclear in nature. It is then of key importance to understand the sources of environmental radioxenon to be able to distinguish civil sources from those of a nuclear explosion. Based on several years of measurements, combined with advanced atmospheric transport model results, it was recently shown that the main source of radioxenon observations are strong and regular batch releases from a very limited number of medical isotope production facilities. This paper reviews production processes in different medical isotope facilities during which radioxenon is produced. Radioxenon activity concentrations and isotopic compositions are calculated for six large facilities. The results are compared with calculated signals from nuclear explosions. Further, the outcome is compared and found to be consistent with radioxenon measurements recently performed in and around three of these facilities. Some anomalies in measurements in which {sup 131m}Xe was detected were found and a possible explanation is proposed. It was also calculated that the dose rate of the releases is well below regulatory values. Based on these results, it should be possible to better understand, interpret and verify signals measured in the noble gas measurement systems in the International Monitoring of the Comprehensive Nuclear-Test-Ban Treaty.

Saey, Paul R.; Bowyer, Ted W.; Ringbom, Anders

2010-09-09T23:59:59.000Z

194

High Flux Isotope Reactor power upgrade status  

SciTech Connect (OSTI)

A return to 100-MW operation is being planned for the High Flux Isotope Reactor (HFIR). Recent improvements in fuel element manufacturing procedures and inspection equipment will be exploited to reduce hot spot and hot streak factors sufficiently to permit the power upgrade without an increase in primary coolant pressure. Fresh fuel elements already fabricated for future use are being evaluated individually for power upgrade potential based on their measured coolant channel dimensions.

Rothrock, R.B.; Hale, R.E. [Oak Ridge National Lab., TN (United States); Cheverton, R.D. [Delta-21 Resources Inc., Oak Ridge, TN (United States)

1997-03-01T23:59:59.000Z

195

Concerning the Facility for Rare Isotope Beams  

ScienceCinema (OSTI)

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

Symons, James

2013-05-29T23:59:59.000Z

196

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

197

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

198

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

199

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

200

Magnesium isotopic systematics of chondrules and CAIs from Allende, Murchison, Murray and Bjurbole. F.-, M. Wadhwa1,  

E-Print Network [OSTI]

Magnesium isotopic systematics of chondrules and CAIs from Allende, Murchison, Murray and Bjurbole: Magnesium isotopic analyses were performed at the Isotope Geochemistry Labora- tory of the Field Museum

Grossman, Lawrence

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Climate change deduced from isotopes in tree rings  

SciTech Connect (OSTI)

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

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

1997-11-01T23:59:59.000Z

202

Standard test method for analysis of isotopic composition of uranium in nuclear-grade fuel material by quadrupole inductively coupled plasma-mass spectrometry  

E-Print Network [OSTI]

1.1 This test method is applicable to the determination of the isotopic composition of uranium (U) in nuclear-grade fuel material. The following isotopic weight percentages are determined using a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS): 233U, 234U, 235U, 236U, and 238U. The analysis can be performed on various material matrices after acid dissolution and sample dilution into water or dilute nitric (HNO3) acid. These materials include: fuel product, uranium oxide, uranium oxide alloys, uranyl nitrate (UNH) crystals, and solutions. The sample preparation discussed in this test method focuses on fuel product material but may be used for uranium oxide or a uranium oxide alloy. Other preparation techniques may be used and some references are given. Purification of the uranium by anion-exchange extraction is not required for this test method, as it is required by other test methods such as radiochemistry and thermal ionization mass spectroscopy (TIMS). This test method is also described i...

American Society for Testing and Materials. Philadelphia

2000-01-01T23:59:59.000Z

203

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 OpenEI Reference LibraryAdd to library Journal...

204

Isotope and Temperature Effects in Liquid Water Probed by Soft...  

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

of temperature and isotope substitution (replacing the hydrogen with deuterium to make "heavy" water). Their findings shed new light on the unique microscopic and macroscopic...

205

Chemical And Isotopic Investigation Of Warm Springs Associated...  

Open Energy Info (EERE)

water (high TDS, > 5000 mgl). Deviations from the meteoric water line are the result of rock-water isotopic exchange, mixing or evaporation. Fluid source regions and residence...

206

Lead and strontium isotopic evidence for crustal interaction...  

Open Energy Info (EERE)

and strontium isotopic evidence for crustal interaction and compositional zonation in the source regions of Pleistocene basaltic and rhyolitic magmas of the Coso volcanic field,...

207

Geochemistry and Isotopes of Fluids from Sulphur Springs, Valles...  

Open Energy Info (EERE)

and Isotopes of Fluids from Sulphur Springs, Valles Caldera, New Mexico Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Geochemistry and...

208

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

Open Energy Info (EERE)

Range Province, Western North America- Evidence For Deep Permeable Pathways Abstract Fluids from the western margin of the Basin and Range have helium isotope ratios as high as...

209

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

Open Energy Info (EERE)

A Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal System Abstract Fluids from springs, fumaroles, and wells throughout Dixie Valley, NV were analyzed for noble...

210

Integrated Approach to Use Natural Chemical and Isotopic Tracers...  

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

Integrated Approach to Use Natural Chemical and Isotopic Tracers to Estimate Fracture Spacing and Surface Area in EGS Systems Integrated Approach to Use Natural Chemical and...

211

Integrated Approach to Use Natural Chemical and Isotopic Tracers...  

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

Approach to Use Natural Chemical and Isotopic Tracers to Estimate Fracture Spacing and Surface Area in EGS Systems B. Mack Kennedy (Presenter) and H. H. Liu Lawrence Berkeley...

212

Hydrogeological And Isotopic Survey Of Geothermal Fields In The...  

Open Energy Info (EERE)

Hydrogeological And Isotopic Survey Of Geothermal Fields In The Buyuk Menderes Graben, Turkey Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

213

Workshop on The Nation's Needs for Isotopes: Present and Future...  

Office of Science (SC) Website

Workshop on The Nation's Needs for Isotopes: Present and Future Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities...

214

Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From...  

Open Energy Info (EERE)

boiling or by isotopic exchange at low waterrock ratios in new fractures. The mineralogy and apparent 18O enrichments of hydrothermal fracture-filling minerals are...

215

Delayed neutron studies of separated isotopes of Br, Rb, I, and Cs  

E-Print Network [OSTI]

Discusses delayed neutron studies of separated isotopes of Br, Rb, I, and Cs are currently in progress at the Spectrometer for On-Line Analysis of Radionuclides (SOLAR) facility operated by Battelle, Pacific Northwest Laboratories. (2 refs).

Reeder, R L; Wright, J F

1976-01-01T23:59:59.000Z

216

Stable Isotope Dynamics in Cownose Rays (Rhinoptera bonasus) within the Northwestern Gulf of Mexico  

E-Print Network [OSTI]

investigation, there is limited information available on feeding patterns of cownose rays in the northwestern Gulf of Mexico. Stable isotope analysis has been used to study the foraging ecology of various species, but only recently applied to elasmobranchs...

St. Clair, Katherine I

2014-07-25T23:59:59.000Z

217

Proton Radioactivity Measurements at HRIBF: Ho, Lu, and Tm Isotopes  

SciTech Connect (OSTI)

Two new isotopes, {sup 145}Tm and {sup 140}Ho and three isomers in previously known isotopes, {sup 141m}Ho, {sup 150m}Lu and {sup 151m}Lu have been discovered and studied via their decay by proton emission. These proton emitters were produced at the Holifield Radioactive Ion Beam Facility (HRIBF) by heavy-ion fusion-evaporation reactions, separated in A/Q with a recoil mass spectrometer (RMS), and detected in a double-sided silicon strip detector (DSSD). The decay energy and half-life was measured for each new emitter. An analysis in terms of a spherical shell model is applied to the Tm and Lu nuclei, but Ho is considerably deformed and requires a collective model interpretation.

Akovali, Y.; Batchelder, J.C.; Bingham, C.R.; Davinson, T.; Ginter, T.N.; Gross, C.J.; Grzywacz, R.; Hamilton, J.H.; Janas, Z.; Karny, M.; Kim, S.H.; MacDonald, B.D.; Mas, J.F.; McConnell, J.W.; Piechaczek, A.; Ressler, J.J.; Rykaczewski, K.; Slinger, R.C.; Szerypo, J.; Toth, K.S.; Weintraub, W.; Woods, P.J.; Yu, C.-H.; Zganjar, E.F.

1998-11-13T23:59:59.000Z

218

GEOCHEMISTRY AND ISOTOPE HYDROLOGY OF GROUNDWATERS IN THE STRIPA GRANITE RESULTS AND PRELIMINARY INTERPRETATION  

E-Print Network [OSTI]

S. Italy). In Isotope Hydrology, IAEA Symposium. Sm-129/53,isotopic variations in hydrology. At. Energy Rev. 14: 621-70 GEOCHEMISTRY AND ISOTOPE HYDROLOGY OF GROUNDWATERS IN THE

Fritz, P.

2011-01-01T23:59:59.000Z

219

E-Print Network 3.0 - argon isotopes Sample Search Results  

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

one of the earliest isotope... this is not always the case--see later). The naturally occurring isotopes of argon are measured by mass spectrometry... isotopes but also small...

220

E-Print Network 3.0 - argon isotopic chains Sample Search Results  

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

one of the earliest isotope... this is not always the case--see later). The naturally occurring isotopes of argon are measured by mass spectrometry... isotopes but also small...

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Source and thermal maturity of bitumen in Precambrian Nonesuch Formation inferred from isotopic compositions of individual normal alkanes  

SciTech Connect (OSTI)

As part of a continuing study of organic geochemistry of the 1.05 Ga Nonesuch Formation in the North American Mid-Continents rift, isotopic compositions of individual normal alkanes were measured using compound-specific isotopic analysis. This is a relatively new technique that can be used in conjunction with traditional biomarker analysis in interpretation of thermal maturity, oil-source rock correlation, and paleoecologic reconstruction. Carbon-isotopic compositions of individual normal alkanes from C{sub 15} to C{sub 25} in five bitumens and one oil from Nonesuch strata vary from {minus}28.8 to {minus}34.5{per thousand} (versus PDB). Within a given sample, isotopic compositions of n-alkanes span a range of 2 to 4 {per thousand}%. Homologues from C{sub 15} to C{sub 19} are isotopically light (depleted) by approximately 0.5{per thousand} relative to higher homologues from C{sub 20} to C{sub 25}. Two sources of normal alkanes are interpreted from the distribution of isotopic compositions. Based on chain length, the series from C{sub 15} to C{sub 19} may have been derived from algal components. Isotopically heavy, higher homologues are suspected to have been derived from bacterial sources. The pattern of isotopic compositions of bitumens is similar to that of the oil, demonstrating an oil-source rock relationship. Superimposed upon this primary, bimodal distribution of normal alkanes is the influence of thermal maturity on isotopic composition. Normal alkanes in samples of higher thermal maturity are enriched isotopically by 0.25 to 2{per thousand} relative to those of lower thermal maturity. Isotopic enrichment with increasing thermal maturity is interpreted to be the result of either addition of isotopically heavy components derived from kerogen and/or preferential loss through cracking of isotopically light components in bitumen.

Hieshima, G.B. (Indiana Univ., Bloomington (United States))

1991-03-01T23:59:59.000Z

222

Isotope Specific Remediation Media and Systems - 13614  

SciTech Connect (OSTI)

On March 11, 2011, now two years ago, the magnitude 9.0 Great East Japan earthquake, Tohoku, hit off the Fukushima coast of Japan. While, of course, most of the outcome of this unprecedented natural and manmade disaster was a negative, both in Japan and worldwide, there have been some extremely invaluable lessons learned and new emergency recovery technologies and systems developed. As always, the mother of invention is necessity. Among these developments has been the development and full-scale implementation of proven isotope specific media (ISMs) with the intent of surgically removing specific hazardous isotopes for the purpose of minimizing dose to workers and the environment. The first such ISMs to be deployed at the Fukushima site were those removing cesium (Cs-137) and iodine (I-129). Since deployment on June 17, 2011, along with treated cooling water recycle, some 70% of the curies in the building liquid wastes have been removed by the Kurion system alone. The current levels of cesium are now only 2% of the original levels. Such an unprecedented, 'external cooling system' not only allowed the eventual cold shut down of the reactors in mid-December, 2011, but has allowed workers to concentrate on the cleanup of other areas of the site. Water treatment will continue for quite some time due to continued leakage into the buildings and the eventual goal of cleaning up the reactors and fuel pools themselves. With the cesium removal now in routine operation, other isotopes of concern are likely to become priorities. One such isotope is that of strontium, and yttrium (Sr-90 and Y-90), which is still at original levels causing further dose issues as well as impediments to discharge of the treated waste waters. For over a year now, a new synthetic strontium specific media has been under development and testing both in our licensed facility in Oak Ridge, Tennessee, but also in confirmatory tests by the Japan Atomic Energy Agency (JAEA) in Japan for Tokyo Electric Power Company (TEPCO). The tests have proven quite successful, even in high salt conditions, and, with loading and dose calculations being completed, will be proposed to add to the existing cesium system. There is no doubt, as high gamma isotopes are removed, other recalcitrant isotopes such as this will require innovative removal media, systems and techniques. Also coming out of this international effort are other ISM media and systems that can be applied more broadly to both Commercial Nuclear Power Plants (NPPs) as well as in Department of Energy (DOE) applications. This cesium and strontium specific media has further been successfully tested in 2012 at a Magnox station in the UK. The resulting proposed mitigation systems for pond and vault cleanup look quite promising. An extremely unusual ISM for carbon 14 (C-14), nickel (Ni-63) and cesium (Cs-137) has been developed for Diablo Canyon NPP for dose reduction testing in their fuel pool. These media will be deployed in Submersible Media Filter (SMF) and Submersible Columns (SC) systems adapted to standard Tri-Nuclear{sup R} housings common in the U.S. and UK. External Vessel Systems (mini-Fukushima) have also been developed as a second mitigation system for D and D and outages. Finally, technetium (Tc- 99) specific media developed for the Waste Treatment Plant (WTP) recycle or condensate (secondary) waste streams (WM 2011) are being further perfected and tested for At-Tank Tc-99 removal, as well as At Tank Cs media. In addition to the on-going media development, systems for deploying such media have developed over the last year and are in laboratory- and full-scale testing. These systems include the fore mentioned Submersible Media Filters (SMF), Submersible Columns (SC) and external pilot- and full-scale, lead-lag, canister systems. This paper will include the media development and testing, as well as that of the deployment systems themselves. (authors)

Denton, Mark S.; Mertz, Joshua L. [Kurion, Inc. Oak Ridge, Tennessee 37831 (United States)] [Kurion, Inc. Oak Ridge, Tennessee 37831 (United States); Morita, Keisuke [Japan Atomic Energy Agency, Tokai Research and Development Center, Fukushima Project Team, Tokai-mura, Ibaraki-ken, 319-1195 (Japan)] [Japan Atomic Energy Agency, Tokai Research and Development Center, Fukushima Project Team, Tokai-mura, Ibaraki-ken, 319-1195 (Japan)

2013-07-01T23:59:59.000Z

223

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

E-Print Network [OSTI]

for the stable isotopes of carbon-13 and oxygen-18 to determine the ratios of the rare (usually the heavy The reaction of acid with calcite produces solid calcium hydrogen phosphate, liquid water, and two gases, water then are exposed to a dry- ice slush, and the carbon dioxide sublimates while the water stays frozen. After two

224

Ammonium transport and reaction in contaminated groundwater: Application of isotope tracers and isotope fractionation studies  

E-Print Network [OSTI]

Ammonium transport and reaction in contaminated groundwater: Application of isotope tracers the groundwater velocity. Retardation factors and groundwater ages indicate that much of the NH4 + in the plume was recharged early in the history of the wastewater disposal. NO3 Ã? and excess N2 gas, which were related

225

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

226

Comparison of isotopic transmutation modelling codes  

E-Print Network [OSTI]

. STAMATELATOS, "Fission Product Data for Thermal Reactors Part 2: Users Manual for EPRI-CINDER Code and Data, " LA-6746-MS, Los Alamos National Laboratory (Dec. 1976). 5. H. BATEMAN, ~RGE~di gH gf ~t gym~id 6. M. J. BEIL, "ORIGEN ? The ORNL Isotope... Generation and Depletion Code, " ORNL-4628, Oak Ridge National Laboratory (May, 1973). 7. O. W. HERMANN and R. M. WESTFALL, "ORIGEN-S Scale System Module to Calculate Fuel Depletion, Actinide Transmutation, Fission Product. Buildup and Decay...

Beard, Carl Allen

1990-01-01T23:59:59.000Z

227

Nuclear Data Evaluations for Americium Isotopes  

SciTech Connect (OSTI)

Recent upgrades of 241Am, 242mAm, and 240Am nuclear data in the keV - 30-MeV range are described. The new evaluation takes advantage of recent measurements and advances in calculational modeling methods. The model calculations are especially important for the nuclear data of americium isotopes, because few measurements are available. The nuclear-model code GNASH is extensively used for our evaluations. The new evaluations are given for total, fission, capture (n, 2n), and (n, 3n) reaction cross sections, and vp for 241Am and 242mAm. A new evaluation for 240Am is also given by expanding our modeling feasibility.

Kawano, T.; Talou, P.; Chadwick, M.B.; MacFarlane, R.E.; Young, P.G. [T-16 Nuclear Physics, Los Alamos National Laboratory (United States)

2005-05-24T23:59:59.000Z

228

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

229

E-Print Network 3.0 - actinide isotope content Sample Search...  

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

by Linda Campbell) Summary: for describing a process that changes the content of the heavy isotope of some element in the substance being... Common Mistakes in Stable isotope...

230

E-Print Network 3.0 - africa sulfur isotope Sample Search Results  

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

By combining the isotopic com- position of the major... Isotopic Composition in Rainwater Chris ... Source: Niyogi, Dev - Department of Agronomy, Purdue University...

231

Magnesium isotopic fractionation in chondrules from the Murchison and Murray CM2 carbonaceous chondrites  

E-Print Network [OSTI]

Magnesium isotopic fractionation in chondrules from the Murchison and Murray CM2 carbonaceous. Investigation of the magnesium isotopic compositions of chondrules can place stringent constraints on the timing

Grossman, Lawrence

232

Facility for Rare Isotope Beams: The Journey Has Begun on DOE...  

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

Facility for Rare Isotope Beams: The Journey Has Begun on DOE's latest Scientific User Facility Facility for Rare Isotope Beams: The Journey Has Begun on DOE's latest Scientific...

233

Radioisotopic Impurities in Promethium-147 Produced at the ORNL High Flux Isotope Reactor.  

E-Print Network [OSTI]

??There is an intense interest in the availability of radioactive isotopes that could be developed into nuclear batteries. Promethium-147 is one of the isotopes of… (more)

Hinderer, James Howard

2010-01-01T23:59:59.000Z

234

E-Print Network 3.0 - analysing pb isotopes Sample Search Results  

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

Mobile Pb-isotopes in Proterozoic sedimentary basins as guides for exploration of uranium deposits... isotope ratios and associated trace element concentrations (U, Th and...

235

Calibration and application of the `clumped isotope' thermometer to foraminifera for high-resolution climate  

E-Print Network [OSTI]

Calibration and application of the `clumped isotope' thermometer to foraminifera for high proxies. Here, we present a new calibration of the `clumped isotope' thermometer to foraminifera based

Gilli, Adrian

236

RADIOGENIC ISOTOPES: TRACERS OF PAST OCEAN CIRCULATION AND EROSIONAL INPUT  

E-Print Network [OSTI]

in the ocean has varied as a function of changes in paleocircu- lation, source provenances, style and intensity-established paleoceano- graphic tracers such as carbon isotopes. INDEX TERMS: 1040 Geochemistry: Isotopic composition Atlantic Deep Water (NADW) according to latest estimates based on results of the World Ocean Circulation

Jellinek, Mark

237

Isotopic composition of stratospheric water vapor: Measurements and photochemistry  

E-Print Network [OSTI]

of magnitude between the surface and the tropopause, and isotopically heavy water is pref- erentially removedIsotopic composition of stratospheric water vapor: Measurements and photochemistry David G. Johnson composition of stratospheric water vapor that result from methane oxidation and reactions with O( ¢¡ ). We

238

Lithium Isotope History of Cenozoic Seawater: Changes in Silicate Weathering  

E-Print Network [OSTI]

Lithium Isotope History of Cenozoic Seawater: Changes in Silicate Weathering and Reverse Weathering 70 Ma · Overview of the Marine Lithium Cycle · Analytical Challenges · 68 Million Year Seawater Lithium Isotope Record (Forams) · Interpretation Standard: NIST L-SVEC Li (SRM 8545) #12;100 Ma Climate

Paytan, Adina

239

Constraining magnesium cycling in marine sediments using magnesium isotopes  

E-Print Network [OSTI]

Constraining magnesium cycling in marine sediments using magnesium isotopes J.A. Higgins *, D Abstract Magnesium concentrations in deep-sea sediment pore-fluids typically decrease down core due to net and differentiate these processes, we have measured magnesium isotopes in pore-fluids and sediment samples from

Paytan, Adina

240

Measuring the Isotopic Composition of Solar Wind Noble Gases  

E-Print Network [OSTI]

noble gases. #12;Exploring the Solar Wind94 Light solar wind noble gases were directly measured by mass of the light gases are known to vary with energy, so none of these provided solar isotopic and elemental5 Measuring the Isotopic Composition of Solar Wind Noble Gases Alex Meshik, Charles Hohenberg, Olga

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Hydrochemical and isotopic effects associated with petroleum fuel biodegradation pathways  

E-Print Network [OSTI]

hydrocarbons and residual electron acceptors have been used to deduce BTEX and MTBE degradation pathways. Benzene and MTBE persist into the denitrification zone, with carbon isotope enrichment of benzene-enrichment of residual benzene gives an apparent e value of Ã?0.66x. MTBE shows no significant isotopic enrichment (d13 C

Sheffield, University of

242

Special Application Thermoelectric Micro Isotope Power Sources  

SciTech Connect (OSTI)

Promising design concepts for milliwatt (mW) size micro isotope power sources (MIPS) are being sought for use in various space and terrestrial applications, including a multitude of future NASA scientific missions and a range of military applications. To date, the radioisotope power sources (RPS) used on various space and terrestrial programs have provided power levels ranging from one-half to several hundred watts. In recent years, the increased use of smaller spacecraft and planned new scientific space missions by NASA, special terrestrial and military applications suggest the need for lower power, including mW level, radioisotope power sources. These power sources have the potential to enable such applications as long-lived meteorological or seismological stations distributed across planetary surfaces, surface probes, deep space micro-spacecraft and sub-satellites, terrestrial sensors, transmitters, and micro-electromechanical systems. The power requirements are in the range of 1 mW to several hundred mW. The primary technical requirements for space applications are long life, high reliability, high specific power, and high power density, and those for some special military uses are very high power density, specific power, reliability, low radiological induced degradation, and very low radiation leakage. Thermoelectric conversion is of particular interest because of its technological maturity and proven reliability. This paper summarizes the thermoelectric, thermal, and radioisotope heat source designs and presents the corresponding performance for a number of mW size thermoelectric micro isotope power sources.

Heshmatpour, Ben; Lieberman, Al; Khayat, Mo; Leanna, Andrew; Dobry, Ted [Teledyne Energy Systems, Incorporated, 10707 Gilroy Road, Hunt Valley, MD 21031 (United States)

2008-01-21T23:59:59.000Z

243

Global Security, Medical Isotopes, and Nuclear Science  

SciTech Connect (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

244

Fuel-Coolant-Interaction modeling and analysis work for the High Flux Isotope Reactor Safety Analysis Report  

SciTech Connect (OSTI)

A brief historical background and a description of short- and long-term task plan development for effective closure of this important safety issue for the HFIR are given. Short-term aspects deal with Fuel-Coolant-Interaction (FCI) issues experimentation, modeling, and analysis for the flow-blockage-induced steam explosion events in direct support of the SAR. Long-term aspects deal with addressing FCI issues resulting from other accidents in conjunction with issues dealing with aluminum ignition, which can result in an order of magnitude increase in overall energetics. Problem formulation, modeling, and computer code simulation for the various phases of steam explosions are described. The evaluation of core melt initiation propagation, and melt superheat are described. Core melt initiation and propagation have been studied using simple conservative models as well as from modeling and analysis using RELAP5. Core debris coolability, heatup, and melting/freezing aspects have been studied by use of the two-dimensional melting/freezing analysis code 2DKO, which was also benchmarked with MELCOR code predictions. Descriptions are provided for the HM, BH, FCIMOD, and CTH computer codes that have been implemented for studying steam explosion energetics from the standpoint of evaluating bounding loads by thermodynamic models or best-estimate loads from one- and two-dimensional simulations of steam explosion energetics. Vessel failure modeling and analysis was conducted using the principles of probabilistic fracture mechanics in conjunction with ADINA code calculations. Top head bolts failure modeling has also been conducted where the failure criterion was based upon stresses in the bolts exceeding the material yield stress for a given time duration. Missile transport modeling and analysis was conducted by setting up a one-dimensional mathematical model that accounts for viscous dissipation, virtual mass effects, and material inertia.

Taleyarkhan, R.P.; Georgevich, V.; Nestor, C.W.; Chang, S.J.; Freels, J.; Gat, U.; Lepard, B.L.; Gwaltney, R.C.; Luttrell, C.; Kirkpatrick, J.

1993-07-01T23:59:59.000Z

245

Photonuclear Reaction Cross Sections for Gallium Isotopes  

E-Print Network [OSTI]

The photon induced reactions which are named as photonuclear reactions have a great importance in many field of nuclear, radiation physics and related fields. Since we have planned to perform photonuclear reaction on gallium target with bremmstrahlung photons from clinical linear accelerator in the future, the cross-sections of neutron (photo-neutron ({\\gamma},xn)) and proton (photo-proton ({\\gamma},xn)) productions after photon activation have been calculated by using TALYS 1.2 computer code in this study. The target nucleus has been considered gallium which has two stable isotopes, 69Ga and 71Ga. According to the results, we have seen that the calculations are in harmony in the limited literature values. Furthermore, the pre-equilibrium and compound process contributions to the total cross-section have been investigated.

Serkan Akkoyun; Tuncay Bayram

2014-09-08T23:59:59.000Z

246

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

247

Isotopic studies of Yucca Mountain soil fluids and carbonate pedogenesis  

SciTech Connect (OSTI)

Secondary carbonates occurring within the soils, faults, and subsurface fractures of Yucca Mountain contain some of the best available records of paleoclimate and palehydrology for the potential radioactive waste repository site. This article discusses conceptual and analytical advances being made with regard to the interpretation of stable isotope data from pedogenic carbonates, specifically related to the {sup 13}C content of soil CO{sub 2}, CaCO{sub 3}, precipitation mechanisms, and isotopic fractionations between parent fluids and precipitating carbonates. The {sup 13}C content of soil carbon dioxide from Yucca Mountain and vicinity shows most of the usual patterns expected in such contexts: Decreasing {sup 13}C content with depth decreasing {sup 13}C with altitude and reduced {sup 13}C during spring. These patterns exist within the domain of a noisy data set; soil and vegetational heterogeneities, weather, and other factors apparently contribute to isotopic variability in the system. Several soil calcification mechanisms appear to be important, involving characteristic physical and chemical environments and isotopic fractionations. When CO{sub 2} loss from thin soil solutions is an important driving factor, carbonates may contain excess heavy isotopes, compared to equilibrium precipitation with soil fluids. When root calcification serves as a proton generator for plant absorption of soil nutrients, heavy isotope deficiencies are likely. Successive cycles of dissolution and reprecipitation mix and redistribute pedogenic carbonates, and tend to isotopically homogenize and equilibrate pedogenic carbonates with soil fluids.

McConnaughey, T.A.; Whelan, J.F.; Wickland, K.P.; Moscati, R.J.

1994-12-31T23:59:59.000Z

248

Yucca Mountain Area Saturated Zone Dissolved Organic Carbon Isotopic Data  

SciTech Connect (OSTI)

Groundwater samples in the Yucca Mountain area were collected for chemical and isotopic analyses and measurements of water temperature, pH, specific conductivity, and alkalinity were obtained at the well or spring at the time of sampling. For this project, groundwater samples were analyzed for major-ion chemistry, deuterium, oxygen-18, and carbon isotopes of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC). The U.S. Geological Survey (USGS) performed all the fieldwork on this project including measurement of water chemistry field parameters and sample collection. The major ions dissolved in the groundwater, deuterium, oxygen-18, and carbon isotopes of dissolved inorganic carbon (DIC) were analyzed by the USGS. All preparation and processing of samples for DOC carbon isotopic analyses and geochemical modeling were performed by the Desert Research Institute (DRI). Analysis of the DOC carbon dioxide gas produced at DRI to obtain carbon-13 and carbon-14 values was conducted at the University of Arizona Accelerator Facility (a NSHE Yucca Mountain project QA qualified contract facility). The major-ion chemistry, deuterium, oxygen-18, and carbon isotopes of DIC were used in geochemical modeling (NETPATH) to determine groundwater sources, flow paths, mixing, and ages. The carbon isotopes of DOC were used to calculate groundwater ages that are independent of DIC model corrected carbon-14 ages. The DIC model corrected carbon-14 calculated ages were used to evaluate groundwater travel times for mixtures of water including water beneath Yucca Mountain. When possible, groundwater travel times were calculated for groundwater flow from beneath Yucca Mountain to down gradient sample sites. DOC carbon-14 groundwater ages were also calculated for groundwaters in the Yucca Mountain area. When possible, groundwater travel times were estimated for groundwater flow from beneath Yucca Mountain to down gradient groundwater sample sites using the DOC calculated groundwater ages. The DIC calculated groundwater ages were compared with DOC calculated groundwater ages and both of these ages were compared to travel times developed in ground-water flow and transport models. If nuclear waste is stored in Yucca Mountain, the saturated zone is the final barrier against the release of radionuclides to the environment. The most recent rendition of the TSPA takes little credit for the presence of the saturated zone and is a testament to the inadequate understanding of this important barrier. If radionuclides reach the saturated zone beneath Yucca Mountain, then there is a travel time before they would leave the Yucca Mountain area and flow down gradient to the Amargosa Valley area. Knowing how long it takes groundwater in the saturated zone to flow from beneath Yucca Mountain to down gradient areas is critical information for potential radionuclide transport. Radionuclide transport in groundwater may be the quickest pathway for radionuclides in the proposed Yucca Mountain repository to reach land surface by way of groundwater pumped in Amargosa Valley. An alternative approach to ground-water flow and transport models to determine the travel time of radionuclides from beneath Yucca Mountain to down gradient areas in the saturated zone is by carbon-14 dating of both inorganic and organic carbon dissolved in the groundwater. A standard method of determining ground-water ages is to measure the carbon-13 and carbon-14 of DIC in the groundwater and then correct the measured carbon-14 along a flow path for geochemical reactions that involve carbon containing phases. These geochemical reactions are constrained by carbon-13 and isotopic fractionations. Without correcting for geochemical reactions, the ground-water ages calculated from only the differences in carbon-14 measured along a flow path (assuming the decrease in carbon-14 is due strictly to radioactive decay) could be tens of thousands of years too old. The computer program NETPATH, developed by the USGS, is the best geochemical program for correcting carbon-14 activities for geochemical r

Thomas, James; Decker, David; Patterson, Gary; Peterman, Zell; Mihevc, Todd; Larsen, Jessica; Hershey, Ronald

2007-06-25T23:59:59.000Z

249

Nitrogen Isotopic Composition of Coal-Fired Power Plant NOx: Influence of Emission Controls and Implications for Global Emission  

E-Print Network [OSTI]

Nitrogen Isotopic Composition of Coal-Fired Power Plant NOx: Influence of Emission Controls from coal-fired power plants in the U.S. at typical operating conditions with and without the presence this, a novel method for collection and isotopic analysis of coal-fired stack NOx emission samples

Elliott, Emily M.

250

The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems  

E-Print Network [OSTI]

The JET Hydrogen-Oxygen Recombination Sensor – A Safety Device for Hydrogen Isotope Processing Systems

251

Stable isotope studies. Final report, March 1, 1972--February 29, 1992  

SciTech Connect (OSTI)

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.

1992-10-01T23:59:59.000Z

252

Evolution of the geothermal fluids at Los Azufres, Mexico, as traced by noble gas isotopes, 18  

E-Print Network [OSTI]

Evolution of the geothermal fluids at Los Azufres, Mexico, as traced by noble gas isotopes, 18 O, D: Noble gases Strontium isotopes Helium isotopes Geothermal energy Los Azufres Araró Mexico Isotopes of noble gases, CO2, H2O and Sr were measured in 10 geothermal wells and 8 hot springs, fumaroles and mud

Long, Bernard

253

Glaciation, aridification, and carbon sequestration in the Permo-Carboniferous: The isotopic record from low latitudes  

E-Print Network [OSTI]

Glaciation, aridification, and carbon sequestration in the Permo-Carboniferous: The isotopic record and carbon sequestration in the Late Paleozoic, we have compiled new and published oxygen and carbon isotopic Carboniferous Stable isotopes Carbon cycling Brachiopods To evaluate the isotopic record of climate change

Grossman, Ethan L.

254

Isotope mass shift for two-electron atoms Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia  

E-Print Network [OSTI]

, 188300, Russia (Dated: 29 April 2004) Accurate calculations of the isotope shift for atomic transitions

Kozlov, Mikhail G

255

Isotope mass shift for two-electron atoms II Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia  

E-Print Network [OSTI]

, Gatchina, 188300, Russia (Dated: 31 October 2006) Accurate calculations of the isotope shift for atomic

Kozlov, Mikhail G

256

Preservation of seawater Sr and Nd isotopes in fossil sh teeth: bad news and good news  

E-Print Network [OSTI]

system, our Nd concentration data, combined with published isotopic and rare earth element data, suggest on the global seawater Sr isotope curve. For Sites 1090, 757, and 807 Sr isotopic values of the pore fluids Nd isotopic compositions from the time of deposition. Ã? 2004 Elsevier B.V. All rights reserved

Martin, Ellen

257

Isotopic mass-dependence of noble gas diffusion coefficients inwater  

SciTech Connect (OSTI)

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

Bourg, I.C.; Sposito, G.

2007-06-25T23:59:59.000Z

258

Isotope and Nuclear Chemistry Division annual report, FY 1983  

SciTech Connect (OSTI)

This report describes progress in the major research and development programs carried out in FY 1983 by the Isotope and Nuclear Chemistry Division. It covers radiochemical diagnostics of weapons tests; weapons radiochemical diagnostics research and development; other unclassified weapons research; stable and radioactive isotope production, separation, and applications (including biomedical applications); element and isotope transport and fixation; actinide and transition metal chemistry; structural chemistry, spectroscopy, and applications; nuclear structure and reactions; irradiation facilities; advanced analytical techniques; development and applications; atmospheric chemistry and transport; and earth and planetary processes.

Heiken, J.H.; Lindberg, H.A. (eds.)

1984-05-01T23:59:59.000Z

259

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

E-Print Network [OSTI]

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

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

2005-06-22T23:59:59.000Z

260

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

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

late 1950s as a production reactor to meet anticipated demand for transuranic isotopes ("heavy" elements such as plutonium and curium). HFIR today is a DOE Office of Science User...

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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 Geochemistry of Thermal and Nonthermal Waters in the...  

Open Energy Info (EERE)

geothermal fluids display a positive oxygen 18 shift of not less than 2 because of rock-water isotopic exchange at 220-300C. The Valles geothermal system is capped by a...

262

Isotopic Effect on Ion Mobility and Separation of Isotopomers...  

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

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

263

Surface-cycling of rhenium and its isotopes  

E-Print Network [OSTI]

The application of elemental and isotopic metal palaeoredox tracers to the geologic past rests on an understanding of modern metal cycles. This study reevaluates the surface-cycling of Mo and Re in near-surface reservoirs. ...

Miller, Christian Alexander

2009-01-01T23:59:59.000Z

264

CONSERVATION ECOLOGY -ORIGINAL RESEARCH Conservation through connectivity: can isotopic gradients  

E-Print Network [OSTI]

CONSERVATION ECOLOGY - ORIGINAL RESEARCH Conservation through connectivity: can isotopic gradients Abstract Conservation of migratory wildlife requires knowledge of migratory connectivity between breeding conservation efforts for endangered migratory species (Webster et al. 2002; Rubenstein and Hobson 2004; Webster

Richner, Heinz

265

Preliminary study: isotopic safeguards techniques (IST) LMFBR fuel cycles  

SciTech Connect (OSTI)

This memorandum presents the preliminary results of the effort to investigate the applicability of isotope correlation techniques (ICT), formulated for the LWR system, to the LMFBR fuel cycle. The detailed isotopic compositional changes with burnup developed for the CRBR was utilized as the reference case. This differs from the usual LMFBR design studies in that the core uranium is natural uranium rather than depleted. Nevertheless, the general isotopic behavior should not differ significantly and does allow an initial insight into the expected behavior of isotopic correlations for the LMFBR power systems such as: the U.K. PFR and reprocessing plant; the French Phenix and Superphenix; and the US reference conceptual design studies (CDS) of homogeneous and heterogeneous LMFBR systems as they are developed.

Persiani, P.J.; Kroc, T.K.

1980-06-01T23:59:59.000Z

266

FY09 PROGRESS: MULTI-ISOTOPE PROCESS (MIP) MONITOR  

SciTech Connect (OSTI)

Model and experimental estimates of the Multi-Isotope Process Monitor performance for determining burnup after dissolution and acid concentration during solvent extraction steps during reprocessing of spent nuclear fuel are presented.

Schwantes, Jon M.; Orton, Christopher R.; Fraga, Carlos G.; Christensen, Richard; Laspe, Amy R.; Ward, Rebecca M.

2009-10-18T23:59:59.000Z

267

Process for exchanging hydrogen isotopes between gaseous hydrogen and water  

DOE Patents [OSTI]

A process for exchanging isotopes of hydrogen, particularly tritium, between gaseous hydrogen and water is provided whereby gaseous hydrogen depeleted in tritium and liquid or gaseous water containing tritium are reacted in the presence of a metallic catalyst.

Hindin, Saul G. (Mendham, NJ); Roberts, George W. (Westfield, NJ)

1980-08-12T23:59:59.000Z

268

Delayed neutron energy spectrum measurements of actinide waste isotopes  

E-Print Network [OSTI]

was irradiated using the Texas A&M Nuclear Science Center Reactor (NSCR). Three proton recoil detectors, operating individually, in conjunction with MCNP calculated response functions, were used to measure the delayed neutron energy spectra of each isotope...

Comfort, Christopher M.

2012-06-07T23:59:59.000Z

269

COLLOQUIUM: Facility for Rare Isotope Beams - Scientific Opportunities...  

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

2015, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Facility for Rare Isotope Beams - Scientific Opportunities and Technical Challenges Dr. Georg Bollen Michigan State...

270

acid selective isotope: Topics by E-print Network  

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

Bchner; Grard Trnec; Jacques Vigu 2006-11-17 20 LACK OF CORRELATION BETWEEN GOUT AND THE INCORPORATION OF ISOTOPIC FORMATE INTO URIC ACID CiteSeer Summary: Certain...

271

Mantle Helium And Carbon Isotopes In Separation Creek Geothermal...  

Open Energy Info (EERE)

we present the helium and carbon isotope results from the initial study of a fluid chemistry-monitoring program started in the summer of 2001 near the South Sister volcano in...

272

AN INVESTIGATION OF THE ISOTOPES OF AMERICIUM AND CURIUM  

E-Print Network [OSTI]

OF THE ISOTOPES OF AMERICIUM AND CURIUM Gary Hoyt Higgins (of alpha particles of americium produced by bombarding puMU3507 Fig. 2. Decay of americium produced by bombardment of

Higgins, Gary Hoyt.

2011-01-01T23:59:59.000Z

273

Intraseasonal variability in South America recorded in stable water isotopes  

E-Print Network [OSTI]

Intraseasonal variability in South America recorded in stable water isotopes Christophe Sturm,1 cores (South America) has illustrated the key role such archives can play in past climate South America, highlighting the internal atmospheric variability, as opposed to external forcing

Sturm, Christophe "Kristof"

274

The Nonactinide Isotope and Sealed Sources Management Group  

SciTech Connect (OSTI)

The Nonactinide Isotope and Sealed Sources Management Group (NISSMG) is sponsored by the Department of Energy (DOE) Office of Environmental Management and managed by Albuquerque Operations Office (DOE/AL) to serve as a complex-wide resource for the management of DOE-owned Nonactinide Isotope and Sealed Source (NISS) materials. NISS materials are defined as including: any isotope in sealed sources or standards; and isotopes, regardless of form, with atomic number less than 90. The NISSMG assists DOE sites with the storage, reuse, disposition, transportation, and processing of these materials. The NISSMG has focused its efforts to date at DOE closure sites due to the immediacy of their problems. Recently, these efforts were broadened to include closure facilities at non-closure sites. Eventually, the NISSMG plans to make its resources available to all DOE sites. This paper documents the lessons learned in managing NISS materials at DOE sites to date.

Low, J. L.; Polansky, G. F.; Parks, D. L.

2002-02-27T23:59:59.000Z

275

The marine geochemistry of iron and iron isotopes  

E-Print Network [OSTI]

This thesis addressed questions about the Fe cycle by measuring detailed profiles and transects of Fe species in the ocean and also by exploring the use of a new tracer of Fe, Fe isotopic fractionation. In the subtropical ...

Bergquist, Bridget A., 1973-

2004-01-01T23:59:59.000Z

276

abundance isotopic: Topics by E-print Network  

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

24 Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming Environment of N113 Astrophysics (arXiv) Summary: With the goal of deriving the physical and...

277

Technology verification phase. Dynamic isotope power system. Final report  

SciTech Connect (OSTI)

The Phase I requirements of the Kilowatt Isotope Power System (KIPS) program were to make a detailed Flight System Conceptual Design (FSCD) for an isotope fueled organic Rankine cycle power system and to build and test a Ground Demonstration System (GDS) which simulated as closely as possible the operational characteristics of the FSCD. The activities and results of Phase II, the Technology Verification Phase, of the program are reported. The objectives of this phase were to increase system efficiency to 18.1% by component development, to demonstrate system reliability by a 5000 h endurance test and to update the flight system design. During Phase II, system performance was improved from 15.1% to 16.6%, an endurance test of 2000 h was performed while the flight design analysis was limited to a study of the General Purpose Heat Source, a study of the regenerator manufacturing technique and analysis of the hardness of the system to a laser threat. It was concluded from these tests that the GDS is basically prototypic of a flight design; all components necessary for satisfactory operation were demonstrated successfully at the system level; over 11,000 total h of operation without any component failure attested to the inherent reliability of this type of system; and some further development is required, specifically in the area of performance. (LCL)

Halsey, D.G.

1982-03-10T23:59:59.000Z

278

Configuration mixing of angular-momentum projected triaxial relativistic mean-field wave functions. II. Microscopic analysis of low-lying states in magnesium isotopes  

E-Print Network [OSTI]

The recently developed structure model that uses the generator coordinate method to perform configuration mixing of angular-momentum projected wave functions, generated by constrained self-consistent relativistic mean-field calculations for triaxial shapes (3DAMP+GCM), is applied in a systematic study of ground states and low-energy collective states in the even-even magnesium isotopes $^{20-40}$Mg. Results obtained using a relativistic point-coupling nucleon-nucleon effective interaction in the particle-hole channel, and a density-independent $\\delta$-interaction in the pairing channel, are compared to data and with previous axial 1DAMP+GCM calculations, both with a relativistic density functional and the non-relativistic Gogny force. The effects of the inclusion of triaxial degrees of freedom on the low-energy spectra and E2 transitions of magnesium isotopes are examined.

J. M. Yao; H. Mei; H. Chen; J. Meng; P. Ring; D. Vretenar

2010-06-08T23:59:59.000Z

279

Lithium isotopic systematics of A-type granites and their mafic enclaves: Further constraints on the Li isotopic composition of the continental crust  

E-Print Network [OSTI]

Lithium isotopic systematics of A-type granites and their mafic enclaves: Further constraints form 6 February 2009 Accepted 15 February 2009 Editor: D.B. Dingwell Keywords: Lithium isotopes A-type granite Mafic enclave Continental crust Lithium concentrations and isotopic compositions of 39 A

Mcdonough, William F.

280

New Mexico Center for Isotopes in Medicine  

SciTech Connect (OSTI)

The purpose of the New Mexico Center for Isotopes in Medicine (NMCIM) is to support research, education and service missions of the UNM College of Pharmacy Radiopharmaceutical Sciences Program (COP RSP) and the Cancer Research and Treatment Center (CRTC). NMCIM developed and coordinated unique translational research in cancer radioimaging and radiotherapy agents based on novel molecules developed at UNM and elsewhere. NMCIM was the primary interface for novel radioisotopes and radiochemistries developed at the Los Alamos National Laboratory (LANL) for SPECT/PET imaging and therapy. NMCIM coordinated the use of the small animal imaging facility with the CRTC provided support services to assist investigators in their studies. NMCIM developed education and training programs that benefited professional, graduate, and postdoctoral students that utilized its unique facilities and technologies. UNM COP RSP has been active in writing research and training grants, as well as supporting contract research with industrial partners. The ultimate goal of NMCIM is to bring new radiopharmaceutical imaging and therapeutic agents into clinical trials that will benefit the health and well being of cancer and other patients in New Mexico and the U.S.

Burchiel, Scott W.

2012-12-13T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

IUPAC Periodic Table of Isotopes for the Educational Community  

SciTech Connect (OSTI)

John Dalton first proposed the concept of atomic weights of the elements in the first decade of the nineteenth century. These atomic weights of the chemical elements were thought of as constants of nature, similar to the speed of light. Dmitri Mendeleev arranged the atomic weights of the elements in ascending order of value and used the systematic variation of their chemical properties to produce his Periodic Table of the Elements in 1869. Measurement of atomic weight values became an important chemical activity for a century and a half. Theodore Richards received a Noble Prize for his work in this area. In 1913, Fredrick Soddy found a species of radium, which had an atomic weight value of 228, compared to the familiar radium gas value of 226. Soddy coined the term 'isotope' (Greek for 'in the same place') to account for this second atomic weight value in the radium position of the Periodic Table. Both of these isotopes of radium are radioactive. Radioactive isotopes are energetically unstable and will decay (disintegrate) over time. The time it takes for one half of a sample of a given radioactive isotope to decay is the half-life of that isotope. In addition to having different atomic weight values, radium-226 and radium-228 also have different half-life values. Around the same time as Soddy's work, J.J. Thomson (discoverer of the electron) identified two stable (non-radioactive) isotopes of the same element, neon. Over the next 40 years, the majority of the known chemical elements were found to have two or more stable (or long-lived radioactive isotopes that contribute significantly to the determination of the atomic weights of the elements).

Holden N. E.; Holden,N.E.; Coplen,T.B.

2012-07-15T23:59:59.000Z

282

The use of carbon stable isotope ratios in drugs characterization  

SciTech Connect (OSTI)

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

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

2013-11-13T23:59:59.000Z

283

Natural mercury isotope variation in coal deposits and organic soils  

SciTech Connect (OSTI)

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

284

Detecting infiltration and impacts of introduced water using strontium isotopes  

SciTech Connect (OSTI)

Water introduced to surface drainages, such as agricultural and roadway runoff, mine drainage, or coalbed natural gas (CBNG)-produced water, potentially can be of environmental concern. In order to mitigate potential environmental effects, it may be important to be able to trace water discharged to the surface as it infiltrates and interacts with near-surface aquifers. We have chosen to study water withdrawn during CBNG production for isotope tracing in the hyporheic zone because it poses a variety of economic, environmental, and policy issues in the Rocky Mountain states. Ground water quality must be protected as CBNG water is added to semiarid ecosystems. Strontium (Sr) isotopes are effective fingerprints of the aquifer from which water originates. In this study, CBNG water was found to have a higher Sr-87/Sr-86 ratio than the local alluvial aquifer water. This measurable difference allows the strontium isotope ratio and concentration to be used as tracers of CBNG water following its discharge to the surface. The dissolution and mobilization of salts from soil are an important contributor to ground water quality degradation. In the Powder River basin of Wyoming, the soils are calcium carbonate-buffered systems. The chemical similarity of strontium to calcium allows it to substitute into calcium minerals and enabled us to use strontium isotopes to identify calcium salts mobilized from the soil. Strontium isotopes are an effective monitor of the source of ions and the volume and direction of introduced water flow in the hyporheic zone.

Brinck, E.L.; Frost, C.D. [University of Wyoming, Laramie, WY (United States). Dept. of Geology & Geophysics

2007-09-15T23:59:59.000Z

285

System for recovery of daughter isotopes from a source material  

DOE Patents [OSTI]

A method of separating isotopes from a mixture containing at least two isotopes in a solution is disclosed. A first isotope is precipitated and is collected from the solution. A daughter isotope is generated and collected from the first isotope. The invention includes a method of producing an actinium-225/bismuth-213 product from a material containing thorium-229 and thorium-232. A solution is formed containing nitric acid and the material containing thorium-229 and thorium-232, and iodate is added to form a thorium iodate precipitate. A supernatant is separated from the thorium iodate precipitate and a second volume of nitric acid is added to the thorium iodate precipitate. The thorium iodate precipitate is stored and a decay product comprising actinium-225 and bismuth-213 is generated in the second volume of nitric acid, which is then separated from the thorium iodate precipitate, filtered, and treated using at least one chromatographic procedure. A system for producing an actinium-225/bismuth-213 product is also disclosed.

Tranter, Troy J. (Idaho Falls, ID) [Idaho Falls, ID; Todd, Terry A. (Aberdeen, ID) [Aberdeen, ID; Lewis, Leroy C. (Idaho Falls, ID) [Idaho Falls, ID; Henscheid, Joseph P. (Idaho Falls, ID) [Idaho Falls, ID

2009-08-04T23:59:59.000Z

286

The use of otolith strontium isotopes (87Sr/86Sr) to identify nursery habitat for a threatened estuarine fish  

E-Print Network [OSTI]

9672-3 The use of otolith strontium isotopes ( 87 Sr/ 86 Sr)relationship between strontium isotope ratios ( 87 Sr/ 86indicate that otolith strontium isotopes ( 87 Sr/ 86 Sr) are

Hobbs, James A.; Lewis, Levi S.; Ikemiyagi, Naoaki; Sommer, Ted; Baxter, Randall D.

2010-01-01T23:59:59.000Z

287

Identification of chemical sedimentary protoliths using iron isotopes in the N3750 Ma Nuvvuagittuq supracrustal belt, Canada  

E-Print Network [OSTI]

Identification of chemical sedimentary protoliths using iron isotopes in the N3750 Ma Nuvvuagittuq partly homogenized Fe isotopes. Variable Fe isotope compositions of bulk quartz­magnetite rocks

Mojzsis, Stephen J.

288

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

SciTech Connect (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

289

Isotopic Scaling and the Symmetry Energy in Spectator Fragmentation  

E-Print Network [OSTI]

Isotopic effects in the fragmentation of excited target residues following collisions of $^{12}$C on $^{112,124}$Sn at incident energies of 300 and 600 MeV per nucleon were studied with the INDRA 4$\\pi$ detector. The measured yield ratios for light particles and fragments with atomic number $Z \\leq$ 5 obey the exponential law of isotopic scaling. The deduced scaling parameters decrease with increasing centrality to values as low as $\\alpha = 0.25 \\pm 0.02$ for the central event group at 600 MeV per nucleon. Symmetry term coefficients, deduced from these data within the statistical description of isotopic scaling, are near $\\gamma =$ 25 MeV for peripheral and $\\gamma <$ 10 MeV for central collisions.

Auger, G; Begemann-Blaich, M L; Bellaize, N; Bittiger, R; Bocage, F; Borderie, B; Bougault, R; Bouriquet, B; Charvet, J L; Chbihi, A; Dayras, R; Durand, D; Frankland, J D; Galíchet, E; Gourio, D; Guinet, D; Hudan, S; Imme, G; Lautesse, P; Lavaud, F; Legrain, R; López, O; Lynen, U; Müller, W F J; Nalpas, L; Orth, H; Plagnol, E; Raciti, G; Rosato, E; Saija, A; Schwarz, C; Seidel, W; Sfienti, C; Tamain, B; Trautmann, W; Trzcinski, A; Turzó, K; Vient, E; Vigilante, M; Volant, C; Zwieglinski, B; Botvina, A S; The INDRA Collaboration

2004-01-01T23:59:59.000Z

290

Rare Isotopes in Cosmic Explosions and Accelerators on Earth  

ScienceCinema (OSTI)

Rare isotopes are nature?s stepping stones to produce the heavy elements, and they are produced in large quantities in stellar explosions. Despite their fleeting existence, they shape the composition of the universe and the observable features of stellar explosions. The challenge for nuclear science is to produce and study the very same rare isotopes so as to understand the origin of the elements and a range of astronomical observations. I will review the progress that has been made to date in astronomy and nuclear physics, and the prospects of finally addressing many of the outstanding issues with the future Facility for Rare Isotope Beams (FRIB), which DOE will build at Michigan State University.

Hendrik Schatz

2010-01-08T23:59:59.000Z

291

High-Resolution Triple Resonance Autoionization of Uranium Isotopes  

SciTech Connect (OSTI)

The near-threshold autoionization (AI) spectrum of uranium has been investigated by triple-resonance excitation with single-mode continuous lasers. Spectra were recorded over the first {approx}30 cm-1 above the first ionization limit at a resolution of 3x10-4 cm 1 using intermediate states with different J values (6, 7, 8) to assign AI level total angular momentum JAI = 5 to 9. Resonances with widths ranging from 8 MHz to 30 GHz were observed; the strongest ones have JAI = 9 and widths of {approx} 60 MHz. Hyperfine structures for 235U and isotope shifts for 234,235U have been measured in the two intermediate levels and in the final AI level for the most favorable excitation path. These measurements were performed using aqueous samples containing sub-milligram quantities of uranium at natural isotopic abundances, indicating the potential of this approach for trace isotope ratio determinations.

Schumann, Philipp G.; Wendt, K; Bushaw, Bruce A.

2005-11-01T23:59:59.000Z

292

Simple, rapid method for the preparation of isotopically labeled formaldehyde  

DOE Patents [OSTI]

Isotopically labeled formaldehyde (*C.sup..sctn.H.sub.2O) is prepared from labeled methyl iodide (*C.sup..sctn.H.sub.3I) by reaction with an oxygen nucleophile having a pendant leaving group. The mild and efficient reaction conditions result in good yields of *C.sup..sctn.H.sub.2O with little or no *C isotopic dilution. The simple, efficient production of .sup.11CH.sub.2O is described. The use of the .sup.11CH.sub.2O for the formation of positron emission tomography tracer compounds is described. The reaction can be incorporated into automated equipment available to radiochemistry laboratories. The isotopically labeled formaldehyde can be used in a variety of reactions to provide radiotracer compounds for imaging studies as well as for scintillation counting and autoradiography.

Hooker, Jacob Matthew (Port Jefferson, NY); Schonberger, Matthias (Mains, DE); Schieferstein, Hanno (Aabergen, DE); Fowler, Joanna S. (Bellport, NY)

2011-10-04T23:59:59.000Z

293

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

SciTech Connect (OSTI)

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

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

2013-06-24T23:59:59.000Z

294

Dissolved strontium in the subterranean estuary Implications for the marine strontium isotope budget  

E-Print Network [OSTI]

Dissolved strontium in the subterranean estuary ­ Implications for the marine strontium isotope concentrations among sites (0.1­24 lM Sr). Strontium isotope exchange was observed in the STE at five

295

Strontium isotope prole of the early Toarcian (Jurassic) oceanic anoxic event, the duration of ammonite biozones,  

E-Print Network [OSTI]

Strontium isotope pro¢le of the early Toarcian (Jurassic) oceanic anoxic event, the duration% TOC) sediments � 2000 Elsevier Science B.V. All rights reserved. Keywords: strontium; isotope ratios

Fouke, Bruce W.

296

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

E-Print Network [OSTI]

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

Chan, Sharleen

297

E-Print Network 3.0 - aluminium isotopes Sample Search Results  

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

, which was 6.5 in primary aluminium, is now reduced to about 3 to 4. If we now consider Uranium isotopes... in Radium isotopes of the ultra-pure ... Source: Ecole Polytechnique,...

298

Helium and lead isotope geochemistry of oceanic volcanic rocks from the East Pacific and South Atlantic  

E-Print Network [OSTI]

The isotopic evolution of helium and lead in the Earth is coupled by virtue of their common radioactive parents uranium and thorium. The isotopic signatures in oceanic volcanic rocks provide constraints on the temporal ...

Graham, David W. (David William)

1987-01-01T23:59:59.000Z

299

Time dependence of delayed neutron emission for fissionable isotope identification  

SciTech Connect (OSTI)

The time dependence of delayed neutron emission was examined as a method of fissionable isotope identification. A pulsed bremsstrahlung photon beam was used to induce photofission reactions in {sup 238}U, {sup 232}Th, and {sup 239}Pu targets. The resulting delayed neutron emission was recorded between irradiating pulses and is a well-known technique for fissionable material detection. Monitoring the decay of delayed neutron emission between irradiating pulses demonstrates the ability to not only detect the presence of fissionable materials, but also to identify which fissionable isotope is present.

Kinlaw, M.T.; Hunt, A.W. [Idaho Accelerator Center, Idaho State University, Pocatello, Idaho 83209-8263 (United States); Department of Physics, Idaho State University, Pocatello, Idaho 83209-8106 (United States)

2005-06-20T23:59:59.000Z

300

Synthesis and investigation of neutron-rich transuranium isotopes  

SciTech Connect (OSTI)

Spontaneous fission activities produced in the reactions of /sup 13/C, /sup 15/N, /sup 16/O, and /sup 18/O ions with /sup 248/Cm and /sup 249/Bk targets are reported; excitation functions and half-lives of element 104 isotopes are given. Reactions that led to the formation of /sup 259/Fm are discussed in detail. The principal features of the SuperHILAC on-line isotope separator and some of the anticipated applications are described. 14 figures, 2 tables. (RWR)

Nitschke, J.M.

1980-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Infrared Spectroscopy and Stable Isotope Geochemistry of Hydrous Silicate Glasses  

SciTech Connect (OSTI)

The focus of this DOE-funded project has been the study of volatile components in magmas and the atmosphere. Over the twenty-one year period of this project, we have used experimental petrology and stable isotope geochemistry to study the behavior and properties of volatile components dissolved in silicate minerals and melts and glasses. More recently, we have also studied the concentration and isotopic composition of CO2 in the atmosphere, especially in relation to air quality issues in the Los Angeles basin.

Stolper, Edward

2007-03-05T23:59:59.000Z

302

Measurements of stable isotope ratios in milk samples from a farm placed in the mountains of Transylvania  

SciTech Connect (OSTI)

Product origin is of great importance for consumers especially because its association in consumer's perception with food quality, freedom from disease or pollution. Stable isotope ratio analysis is a powerful technique in food authenticity and traceability control which has been introduced within the European wine industry to ensure authenticity of wine provenance and to detect adulteration. Isotopic ratios measurements have also been successfully to other food commodities like: fruit juices, honey and dairy foods. The ?{sup 18}O and ?{sup 2}H content in milk water reflects the isotope composition of the ground water drunk by animals. Seasonal effects are also very important: in summer, milk water contains higher ?{sup 18}O and ?{sup 2}H values due to the fresh plants that are ate by animals. Relative carbon stable isotope abundances in total milk reflect the isotopic composition of the diet fed to the dairy cows. In this study the hydrogen, oxygen and carbon isotopic composition of 15 milk samples coming from a unit placed in the mountains of Transylvania was investigated. The distribution of the obtained isotopic values was than discussed taking into account that all the animals were feed with the same type of forage and consumed water was taken from the same source.

Magdas, D. A., E-mail: gabriela.cristea@itim-cj.ro; Cristea, G., E-mail: gabriela.cristea@itim-cj.ro; Bot, A.; Puscas, R.; Radu, S.; Mirel, V. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania); Cordea, D. V.; Mihaiu, M. [University of Agricultural Science and Veterinary Medicine, 3-5 Calea Manastur, 400372 Cluj-Napoca (Romania)] [University of Agricultural Science and Veterinary Medicine, 3-5 Calea Manastur, 400372 Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

303

E-Print Network 3.0 - anomalous isotope effect Sample Search...  

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

Databases and Resources ; Environmental Sciences and Ecology ; Geosciences 13 Identification of isotopically primitive interplanetary dust particles: A NanoSIMS...

304

Experimental studies of the transfer phenomena of tritium in an isotope exchange column for recovery tritium  

E-Print Network [OSTI]

&D for Cryogenics and Isotopic Separations, Rm.Valcea, Romania, e-mail:anisia@ns-icsi.icsi.ro The processes

305

Method for enriching a middle isotope using vibration-vibration pumping  

DOE Patents [OSTI]

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

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

1989-01-01T23:59:59.000Z

306

Dual isotope notch observer for isotope identification, assay and imaging with mono-energetic gamma-ray sources  

DOE Patents [OSTI]

A dual isotope notch observer for isotope identification, assay and imaging with mono-energetic gamma-ray sources includes a detector arrangement consists of three detectors downstream from the object under observation. The latter detector, which operates as a beam monitor, is an integrating detector that monitors the total beam power arriving at its surface. The first detector and the middle detector each include an integrating detector surrounding a foil. The foils of these two detectors are made of the same atomic material, but each foil is a different isotope, e.g., the first foil may comprise U235 and second foil may comprise U238. The integrating detectors surrounding these pieces of foil measure the total power scattered from the foil and can be similar in composition to the final beam monitor. Non-resonant photons will, after calibration, scatter equally from both foils.

Barty, Christopher P.J.

2013-02-05T23:59:59.000Z

307

Caution on the Use of Liquid Nitrogen Traps in Stable Hydrogen Isotope-Ratio Mass Spectrometry  

E-Print Network [OSTI]

-mail: tbcoplen@usgs.gov. (1) Kirshenbaum, I. In Physical Properties and Analysis of Heavy Water; Urey, H. C with the process of adding liquid nitrogen (LN2) to top off the dewar of a stainless-steel water trap on a gaseous hydrogen-water platinum equilibration system. Al- though the cause of this isotopic fractionation

308

Constraints on Hadean zircon protoliths from oxygen isotopes, Ti-thermometry, and rare earth elements  

E-Print Network [OSTI]

, and analysis of zircon/melt partitioning of rare earth elements (REEs) provide mutually consistent lines, 3 tables. Keywords: Hadean; crust; ion microprobe; oxygen; zircon thermometry; rare earth elements oxygen isotopes, Ti-thermometry, and rare earth elements, Geochem. Geophys. Geosyst., 8, Q06014, doi:10

309

NEUTRON-POOR NICKEL ISOTOPE ANOMALIES IN METEORITES  

SciTech Connect (OSTI)

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

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

2012-10-10T23:59:59.000Z

310

Nuclear criticality safety bounding analysis for the in-tank-precipitation (ITP) process, impacted by fissile isotopic weight fractions  

SciTech Connect (OSTI)

The In-Tank Precipitation process (ITP) receives High Level Waste (HLW) supernatant liquid containing radionuclides in waste processing tank 48H. Sodium tetraphenylborate, NaTPB, and monosodium titanate (MST), NaTi{sub 2}O{sub 5}H, are added for removal of radioactive Cs and Sr, respectively. In addition to removal of radio-strontium, MST will also remove plutonium and uranium. The majority of the feed solutions to ITP will come from the dissolution of supernate that had been concentrated by evaporation to a crystallized salt form, commonly referred to as saltcake. The concern for criticality safety arises from the adsorption of U and Pt onto MST. If sufficient mass and optimum conditions are achieved then criticality is credible. The concentration of u and Pt from solution into the smaller volume of precipitate represents a concern for criticality. This report supplements WSRC-TR-93-171, Nuclear Criticality Safety Bounding Analysis For The In-Tank-Precipitation (ITP) Process. Criticality safety in ITP can be analyzed by two bounding conditions: (1) the minimum safe ratio of MST to fissionable material and (2) the maximum fissionable material adsorption capacity of the MST. Calculations have provided the first bounding condition and experimental analysis has established the second. This report combines these conditions with canyon facility data to evaluate the potential for criticality in the ITP process due to the adsorption of the fissionable material from solution. In addition, this report analyzes the potential impact of increased U loading onto MST. Results of this analysis demonstrate a greater safety margin for ITP operations than the previous analysis. This report further demonstrates that the potential for criticality in the ITP process due to adsorption of fissionable material by MST is not credible.

Bess, C.E.

1994-04-22T23:59:59.000Z

311

Discovery of isotopes of the transuranium elements with 93?Z?98  

SciTech Connect (OSTI)

One hundred and five isotopes of the transuranium elements neptunium, plutonium, americium, curium, berkelium, and californium have been observed so far; the discovery of these isotopes is described. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

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

2013-01-15T23:59:59.000Z

312

Lithium isotopic systematics of granites and pegmatites from the Black Hills, South Dakota  

E-Print Network [OSTI]

Lithium isotopic systematics of granites and pegmatites from the Black Hills, South Dakota Fang compositions may reflect Li isotopic fractionation resulting from extensive crystal-melt fractionation. Lithium fractionation in the near­surface environment of > 60 (Tomascak, 2004). Lithium isotopic fractionation has been

Rudnick, Roberta L.

313

Extreme lithium isotopic fractionation during continental weathering revealed in saprolites from South Carolina  

E-Print Network [OSTI]

Extreme lithium isotopic fractionation during continental weathering revealed in saprolites from in revised form 6 July 2004 Abstract The lithium concentration and isotopic composition of two saprolites the behavior of lithium isotopes during continental weathering. Both saprolites show a general trend

Rudnick, Roberta L.

314

Dynamic isotope effect on the product energy partitioning in CH2OH ~CHO H2  

E-Print Network [OSTI]

Dynamic isotope effect on the product energy partitioning in CH2OH ~CHO H2 Young Min Rheea March 1998; accepted 1 July 1998 The deuterium isotope effect on the product energy partitioning. Close inspection of the potential energy surface revealed that the isotope effect on KER and the product

Kim, Myung Soo

315

PHYSIOLOGICAL ECOLOGY -ORIGINAL PAPER Carbon and hydrogen isotope fractionation under continuous  

E-Print Network [OSTI]

intensity continuous light, e.g., in the High Arctic summer, on plant carbon and hydrogen isotope Introduction Carbon and hydrogen isotope fractionations under low intensity 24-h continuous light were unknownPHYSIOLOGICAL ECOLOGY - ORIGINAL PAPER Carbon and hydrogen isotope fractionation under continuous

316

Abstract.-Stable nitrogen (/ll5Nl and carbon (/ll3CI isotope measure-  

E-Print Network [OSTI]

540 Abstract.-Stable nitrogen (/ll5Nl and carbon (/ll3CI isotope measure- ments were used and the Gulfof Mexico Loop Current. Use of stable isotopes to assess groups of king mackerel, Scomberomorus caval), the carbon isotopic composition of a food source is not substantially altered during assimilation. De

317

Physical controls on the isotopic composition of soil-respired CO2  

E-Print Network [OSTI]

Physical controls on the isotopic composition of soil-respired CO2 Nick Nickerson1 and Dave Risk1] Measurement of the isotopic composition of soil and soil-respired CO2 (d13 CO2) has become an invaluable tool in understanding the effects of diffusive transport on soil CO2 isotopic composition, it is crucial

318

MAGNESIUM ISOTOPIC COMPOSITION OF CAIs AND CHONDRULES FROM CR CHONDRITES. B. , M. Gounelle1  

E-Print Network [OSTI]

MAGNESIUM ISOTOPIC COMPOSITION OF CAIs AND CHONDRULES FROM CR CHONDRITES. B. Mimoun1 , M. Gounelle1. Introduction: The magnesium isotopic composi- tion of primitive extraterrestrial materials is worth measuring.g. 10]. Figure 1: The magnesium isotopic composition of CAIs in CR chondrites. Error bars are 1

Technische Universiteit Delft

319

Control mechanisms for the oceanic distribution of silicon isotopes Andre G. Wischmeyer,1  

E-Print Network [OSTI]

the silicic acid concentration and its silicon isotope composition is not a simple Rayleigh distillation curve to the Rayleigh distillation curve. Model results can be used to predict opal silicon isotope compositions of their pitfalls [Wefer et al., 1999]. [4] Recent work taking advantage of the fractionation of silicon isotopes

Paris-Sud XI, Université de

320

Oxygen isotopic disequilibrium in plagioclasecorundumhercynite xenoliths from the Voisey's Bay Intrusion, Labrador, Canada  

E-Print Network [OSTI]

Oxygen isotopic disequilibrium in plagioclase­corundum­hercynite xenoliths from the Voisey's Bay to skeletal. Ion microprobe analyses indicate that oxygen isotopic equilibrium was neither established during corundum is characterized by 18 O values between 2.5 and 7.6. Oxygen isotopic equilibration with mantle

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

A Pb isotope record of mid-Atlantic US atmospheric Pb emissions in Chesapeake Bay sediments  

E-Print Network [OSTI]

(1998) estimates that prior to the industrial revolution, anthro- pogenic lead was emitted solely Pb isotope record in CB to other Pb isotope records of US industrial atmospheric emissions. Over, industrial atmospheric Pb isotope signal that is representative of the mid-Atlantic region of the US

322

Novel stable-isotope proxies in stalagmites to reconstruct the past Supervisors: Prof. Gideon Henderson  

E-Print Network [OSTI]

about past conditions. Li-isotopes, for instance, respond to changes in weathering intensity (Pistiner carbon cycle feedbacks in the climate system. Ca isotopes, meanwhile, are controlled by the saturation proxies at present). This project will develop the use of Li, Ca and other metal isotopes

Henderson, Gideon

323

Nitrogen isotope dynamics of the Cariaco Basin, Venezuela Robert C. Thunell,1  

E-Print Network [OSTI]

Nitrogen isotope dynamics of the Cariaco Basin, Venezuela Robert C. Thunell,1 Daniel M. Sigman,2 of Venezuela. Water column denitrification occurring in the basin has only a very small isotopic imprint-Karger, Y. Astor, and R. Varela (2004), Nitrogen isotope dynamics of the Cariaco Basin, Venezuela, Global

Sigman, Daniel M.

324

SAS2H Generated Isotopic Concentrations For B&W 15X15 PWR Assembly (SCPB:N/A)  

SciTech Connect (OSTI)

This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide pressurized water reactor (PWR) isotopic composition data as a function of time for use in criticality analyses. The objectives of this evaluation are to generate burnup and decay dependant isotopic inventories and to provide these inventories in a form which can easily be utilized in subsequent criticality calculations.

J.W. Davis

1996-08-29T23:59:59.000Z

325

Isotopic Tracers for Biogeochemical Processes and Contaminant Transport: Hanford, Washington  

SciTech Connect (OSTI)

Our goal is to use isotopic measurements to understand how contaminants are introduced to and stored in the vadose zone, and what processes control migration from the vadose zone to groundwater and then to surface water. We have been using the Hanford Site in south-central Washington as our field laboratory, and our investigations are often stimulated by observations made as part of the groundwater monitoring program and vadose zone characterization activities. Understanding the transport of contaminants at Hanford is difficult due to the presence of multiple potential sources within small areas, the long history of activities, the range of disposal methods, and the continuing evolution of the hydrological system. Observations often do not conform to simple models, and cannot be adequately understood with standard characterization approaches, even though the characterization activities are quite extensive. One of our objectives is to test the value of adding isotopic techniques to the characterization program, which has the immediate potential benefit of addressing specific remediation issues, but more importantly, it allows us to study fundamental processes at the scale and in the medium where they need to be understood. Here we focus on two recent studies at the waste management area (WMA) T-TX-TY, which relate to the sources and transport histories of vadose zone and groundwater contamination and contaminant fluid-sediment interaction. The WMA-T and WMA-TX-TY tank farms are located within the 200 West Area in the central portion of the Hanford Site (Fig. 2). They present a complicated picture of mixed groundwater plumes of nitrate, {sup 99}Tc, Cr{sup 6+}, carbon tetrachloride, etc. and multiple potential vadose zone sources such as tank leaks and disposal cribs (Fig. 3). To access potential vadose zone sources, we analyzed samples from cores C3832 near tank TX-104 and from C4104 near tank T-106. Tank T-106 was involved in a major event in 1973 in which 435,000 L of high activity waste leaked to the vadose zone over a seven-week period. Other nearby tanks (T-103 and T-101) are also suspected of having leaked or overfilled. Pore water from these cores was analyzed for U and Sr isotopic compositions. Increasing {sup 99}Tc concentration in monitoring well 299-W11-39 (to 27,000 pCi/L in 2005) near the northeast corner of the WMA-T area prompted the emplacement of a series of new wells, 299-W11-25B, W11-45 (down gradient), and W11-47 (Fig. 3), during which depth discrete samples were collected below the groundwater surface. The depth profile from W11-25B revealed high {sup 99}Tc concentrations peaking at 182,000 pCi/L at {approx}10 m below the water table (Dresel et al. 2006). We obtained aliquots for isotopic analysis of groundwater samples produced by purge-and-pump sampling during the drilling of W11-25B, -45 and -47. In addition we have analyzed groundwater samples from monitoring wells in the vicinity of WMA T-TX-TY.

Donald J. DePaolo; John N. Christensen; Mark E. Conrad; and P. Evan Dresel

2007-04-19T23:59:59.000Z

326

The Multi-Isotope Process (MIP) Monitor Project: FY13 Final Report  

SciTech Connect (OSTI)

The Multi-Isotope Process (MIP) Monitor provides an efficient approach to monitoring the process conditions in reprocessing facilities in support of the goal of “… (minimization of) the risks of nuclear proliferation and terrorism.” The MIP Monitor measures the distribution of the radioactive isotopes in product and waste streams of a nuclear reprocessing facility. These isotopes are monitored online by gamma spectrometry and compared, in near-real-time, to spectral patterns representing “normal” process conditions using multivariate analysis and pattern recognition algorithms. The combination of multivariate analysis and gamma spectroscopy allows us to detect small changes in the gamma spectrum, which may indicate changes in process conditions. By targeting multiple gamma-emitting indicator isotopes, the MIP Monitor approach is compatible with the use of small, portable, relatively high-resolution gamma detectors that may be easily deployed throughout an existing facility. The automated multivariate analysis can provide a level of data obscurity, giving a built-in information barrier to protect sensitive or proprietary operational data. Proof-of-concept simulations and experiments have been performed in previous years to demonstrate the validity of this tool in a laboratory setting for systems representing aqueous reprocessing facilities. However, pyroprocessing is emerging as an alternative to aqueous reprocessing techniques.

Meier, David E.; Coble, Jamie B.; Jordan, David V.; Mcdonald, Luther W.; Forrester, Joel B.; Schwantes, Jon M.; Unlu, Kenan; Landsberger, Sheldon; Bender, Sarah; Dayman, Kenneth J.; Reilly, Dallas D.

2013-09-01T23:59:59.000Z

327

Determination of americium and curium by isotope dilution  

SciTech Connect (OSTI)

The authors propose a method for the determination of americium and curium in solutions of spent fuels from water cooled and moderated reactors that is based on isotope dilution with Am 241 and Cm 244 combined with extraction chromatography of americium and curium and alpha spectroscopy of the labels.

Yablochkin, A.V.; Krapivin, M.I.; Fedotov, S.N.; Yudina, V.G.; Yakobson, A.A.

1987-11-01T23:59:59.000Z

328

Accelerator based Production of Auger-Electron-emitting Isotopes for  

E-Print Network [OSTI]

- electron-emitting isotopes for targeted radionuclide therapy of cancer. Based on 1st principles dosimetry-photon emission computed tomography (SPECT) to be suitable for SPECT-based dosimetry of a future Sb the nuclear reactions 119Sn(p,n)119Sb and 117Sn(p,n)117Sb including measurements of the excitation function

329

Rare Isotope Beams for the 21st Century  

ScienceCinema (OSTI)

In a scientific keynote address on Friday, June 12 at Michigan State University (MSU) in East Lansing, James Symons, Director of Berkeley Labs Nuclear Science Division (NSD), discussed the exciting research prospects of the new Facility for Rare Isotope Beams (FRIB) to be built at MSUs National Superconducting Cyclotron Laboratory.

James Symons

2010-01-08T23:59:59.000Z

330

Non-eyring temperature dependence of dynamic isotope effects  

E-Print Network [OSTI]

Our group has recently described a new form of kinetic isotope effect that arises from dynamic selectivity in the bifurcation of a reaction pathway on the slope of an energy surface. Since the selection between products does not occur at a potential...

Ruiz, N. Rebecca

2009-05-15T23:59:59.000Z

331

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

Broader source: Energy.gov [DOE]

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.

332

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

Broader source: Energy.gov [DOE]

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.

333

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

Broader source: Energy.gov [DOE]

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.

334

Revised isotopic (40 Ar) age for the lamproite volcano of  

E-Print Network [OSTI]

Revised isotopic (40 Ar/39 Ar) age for the lamproite volcano of Cabezos Negros, Fortuna Basin (lamproites) of the Fortuna Basin in southeast Spain. This age is significantly older than earlier reported K. Because the volcanic rocks are intercalated in the stratigraphic sequence of the Fortuna Basin directly

Utrecht, Universiteit

335

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

Broader source: Energy.gov [DOE]

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.

336

Neutron Stimulated Emission Computed Tomography of Stable Isotopes  

E-Print Network [OSTI]

Neutron Stimulated Emission Computed Tomography of Stable Isotopes Carey E. Floyd Jr.*ab , Calvin North Carolina Keywords: imaging, neutrons, tomography, spectroscopy ABSTRACT Here we report on the development of a new molecular imaging technique using inelastic scattering of fast neutrons. Earlier studies

337

Apparatus and method for monitoring of gas having stable isotopes  

DOE Patents [OSTI]

Gas having stable isotopes is monitored continuously by using a system that sends a modulated laser beam to the gas and collects and transmits the light not absorbed by the gas to a detector. Gas from geological storage, or from the atmosphere can be monitored continuously without collecting samples and transporting them to a lab.

Clegg, Samuel M; Fessenden-Rahn, Julianna E

2013-03-05T23:59:59.000Z

338

Method of enhancing selective isotope desorption from metals  

DOE Patents [OSTI]

This invention relates generally to the field of gas desorption from metals; and, more particularly, to a method of enhancing the selective desorption of a particular isotope of a gas from metals. Enhanced selective desorption is especially useful in the operation of fusion devices.

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

1983-07-26T23:59:59.000Z

339

Mother-embryo isotope (15 C) fractionation and mercury (Hg)  

E-Print Network [OSTI]

used to investigate the trophic ecology, foraging habitats and heavy metal contamination). Consequently, Hg concentrations are important to monitor because of the toxicity of this metal. In order of this element in muscle and liver. Key words: sharks; stable isotopes; trace metal; maternal influence. hal

Paris-Sud XI, Université de

340

Ultralow Thermal Conductivity of Isotope-Doped Silicon Nanowires  

E-Print Network [OSTI]

conductivity of SiNWs is about 2 orders of magnitude smaller than that of bulk crystals.18,19 The low thermal conductivity (0.05 W/m K) found in layered materials.22 So it is indispensable to reduce the thermal conUltralow Thermal Conductivity of Isotope-Doped Silicon Nanowires Nuo Yang, Gang Zhang,*, and Baowen

Li, Baowen

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Carbon and Hydrogen Isotopic Effects in Microbial Methane  

E-Print Network [OSTI]

6 Carbon and Hydrogen Isotopic Effects in Microbial Methane from Terrestrial Environments Jeffrey Chanton, Lia Chaser, Paul Glasser,Don Siegel Methane is the ultimate end-product of anaerobic respiration. Methane production via CO2 reduction does not consume CO2. Also, acetate can be written as 2CH20, so Eq. 6

Saleska, Scott

342

Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes  

SciTech Connect (OSTI)

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

Draayer, Jerry P [Louisiana State University

2014-09-28T23:59:59.000Z

343

IN-SITU STUDY OF OXYGEN ISOTOPES IN GRAPHITE FROM L3 CHONDRITES: INDICATIONS FOR OXYGEN ISOTOPIC HETEROGENEITY. S. Mostefaoui1, FJ. Stadermann2, and A. El Goresy1. !Max-  

E-Print Network [OSTI]

IN-SITU STUDY OF OXYGEN ISOTOPES IN GRAPHITE FROM L3 CHONDRITES: INDICATIONS FOR OXYGEN ISOTOPIC in-situ measurements of oxygen isotopes in graphite from the Khohar and Mez6-Madaras (L3) chondrites. Oxygen isotopic measurements were conducted with the Washington University ion microprobe (a modified

344

Features of adsorbed radioactive chemical elements and their isotopes distribution in iodine air filters AU-1500 at nuclear power plants  

E-Print Network [OSTI]

The main aim of research is to investigate the physical features of spatial distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU1500 in the forced exhaust ventilation systems at the nuclear power plant. The gamma activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU1500 iodine air filter, which was exposed to the bremsstrahlung gamma quantum irradiation, produced by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granule...

Neklyudov, I M; Dikiy, N P; Ledenyov, O P; Lyashko, Yu V

2013-01-01T23:59:59.000Z

345

Transient competitive complexation in biological kinetic isotope fractionation explains non-steady isotopic effects: Theory and application to denitrification in soils  

SciTech Connect (OSTI)

The theoretical formulation of biological kinetic reactions in isotopic applications often assume first-order or Michaelis-Menten-Monod kinetics under the quasi-steady-state assumption to simplify the system kinetics. However, isotopic e ects have the same order of magnitude as the potential error introduced by these simpli cations. Both formulations lead to a constant fractionation factor which may yield incorrect estimations of the isotopic effect and a misleading interpretation of the isotopic signature of a reaction. We have analyzed the isotopic signature of denitri cation in biogeochemical soil systems by Menyailo and Hungate [2006], where high {sup 15}N{sub 2}O enrichment during N{sub 2}O production and inverse isotope fractionation during N{sub 2}O consumption could not be explained with first-order kinetics and the Rayleigh equation, or with the quasi-steady-state Michaelis-Menten-Monod kinetics. When the quasi-steady-state assumption was relaxed, transient Michaelis-Menten-Monod kinetics accurately reproduced the observations and aided in interpretation of experimental isotopic signatures. These results may imply a substantial revision in using the Rayleigh equation for interpretation of isotopic signatures and in modeling biological kinetic isotope fractionation with first-order kinetics or quasi-steady-state Michaelis-Menten-Monod kinetics.

Maggi, F.M.; Riley, W.J.

2009-06-01T23:59:59.000Z

346

Journal of the Geological Society, London, Vol. 155, 1998, pp. 773785. Printed in Great Britain Mineralogy, sulphur isotope geochemistry and the development of sulphide structures  

E-Print Network [OSTI]

Mineralogy, sulphur isotope geochemistry and the development of sulphide structures at the Broken Spur mineralogy and sulphur isotope analysis. Young mound sulphides from Broken Spur have a pyrrhotite- dominated mineralogy unusual for bare ridge vent systems. However, pyrrhotite is metastable and is ultimately converted

347

Features of adsorbed radioactive chemical elements and their isotopes distribution in iodine air filters AU-1500 at nuclear power plants  

E-Print Network [OSTI]

The main aim of research is to investigate the physical features of spatial distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU1500 in the forced exhaust ventilation systems at the nuclear power plant. The gamma activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU1500 iodine air filter, which was exposed to the bremsstrahlung gamma quantum irradiation, produced by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granules of the type of SKT3, in the AU1500 iodine air filter are also researched. The possible influences by the standing acoustic wave of air pressure in the iodine air filter on the spatial distribution of the chemical elements and their isotopes in the iodine air filter are discussed. The comprehensive analysis of obtained research results on the distribution of the adsorbed chemical elements and their isotopes in the absorber of iodine air filter is performed.

I. M. Neklyudov; A. N. Dovbnya; N. P. Dikiy; O. P. Ledenyov; Yu. V. Lyashko

2013-06-21T23:59:59.000Z

348

Laser Based Techniques for Ultra Trace Isotope Production, Spectroscopy and Detection  

SciTech Connect (OSTI)

A variety of research activities in the field of fundamental and applied nuclear physics has evolved in the last years using resonantly tuned radiation from powerful lasers. The technique of resonance ionization spectroscopy has delivered outstanding results and found broad acceptance in the last years as a particularly efficient and highly selective method for rare and exotic radioisotope studies. It is used for production, spectroscopy and detection of these species and provides complete isobaric, high isotopic and even some isomeric selection, which altogether is needed for on-line investigation of short lived species far off stability as well as for ultra trace determination. Good overall efficiency pushes the experimental limits of detection in elemental trace analysis down to below 106 atoms per sample, and additionally isotopic selectivity as high as 3 ? 1012 has been demonstrated. The widespread potential of resonance ionization techniques is discussed, focusing on the experimental arrangements for applications in selective on-line isotope production, spectroscopy of rare radioisotopes and ultra trace determination of radiotoxic isotopes like 238Pu to 244Pu, 135,137Cs, 89,90Sr or 41Ca in environmental, technical and biomedical samples.

Wendt, K.; Blaum, K; Geppert, C; Muller, P; Nortershauser, W.; Schmitt, Annette; Schumann, P; Trautmann, Norbert; Bushaw, Bruce A.

2006-06-26T23:59:59.000Z

349

High Flux Isotope Reactor system RELAP5 input model  

SciTech Connect (OSTI)

A thermal-hydraulic computational model of the High Flux Isotope Reactor (HFIR) has been developed using the RELAP5 program. The purpose of the model is to provide a state-of-the art thermal-hydraulic simulation tool for analyzing selected hypothetical accident scenarios for a revised HFIR Safety Analysis Report (SAR). The model includes (1) a detailed representation of the reactor core and other vessel components, (2) three heat exchanger/pump cells, (3) pressurizing pumps and letdown valves, and (4) secondary coolant system (with less detail than the primary system). Data from HFIR operation, component tests, tests in facility mockups and the HFIR, HFIR specific experiments, and other pertinent experiments performed independent of HFIR were used to construct the model and validate it to the extent permitted by the data. The detailed version of the model has been used to simulate loss-of-coolant accidents (LOCAs), while the abbreviated version has been developed for the operational transients that allow use of a less detailed nodalization. Analysis of station blackout with core long-term decay heat removal via natural convection has been performed using the core and vessel portions of the detailed model.

Morris, D.G.; Wendel, M.W.

1993-01-01T23:59:59.000Z

350

Management of Heavy Isotope in the DOE Complex  

SciTech Connect (OSTI)

Currently each Department Of Energy (DOE) Program office manages its own nuclear materials through activities such as production, processing, storage, transportation, and disposition. However, recognizing the need to strengthen its strategic approach to the integrated life-cycle management of nuclear materials, DOE established the Nuclear Materials Management Stewardship Initiative (NMMSI) in January 2000. The NMMSI's first visible product was the Integrated Nuclear Material Management Plan in which it was generally recommended that DOE take a cross-cutting look at managing its nuclear materials, and specifically recommended that four Nuclear Material Management Groups (NMMGs) be formed. These groups were established to facilitate management of nuclear materials for which DOE has or may have responsibility, including many presently not in DOE's direct control. One of these NMMGs, the Heavy Isotope Management Group (HIMG) was established at Oak Ridge National Laboratory in Dec ember 2000, to facilitate management of (a) actinide and their decay products (except sealed sources) and (b) isotopically enriched stable and radioactive isotopes except uranium and lithium, but excluding thorium, uranium, spent fuel, and weapons or reactor grade plutonium which are addressed by other NMMGs. Despite its short duration and relatively limited funding, the HIMG has facilitated the disposition of heavy isotopes from Lawrence Berkeley National Laboratory (LBNL), Rocky Flats Environmental Technology Site (RFETS), Pacific Northwest National Laboratory (PNNL), Oak Ridge National Laboratory (ORNL), Lawrence Livermore National Laboratory (LLNL), and Idaho National Engineering and Environmental Laboratory (INEEL). The primary disposition options have been to facilitate reuse of valuable heavy isotopes by matching custodians of unwanted materials with other users that seek such materials for new applications. This approach has the dual advantages of avoiding custodian disposal costs plus cost to the user of obtaining newly produced material. The HIMG has also prepared issue papers on neptunium and americium/curium that identify the resources, potential uses, and disposal pathways for the materials across the DOE Complex. In the future the HIMG expects to comprehensively identify the status of the U.S. heavy isotope inventory, prepare additional issue papers and plans charting the future of this inventory, and to facilitate execution of the plan.

Canon, R.; Croff, A.; Boyd, L.

2002-02-27T23:59:59.000Z

351

Isotope production and distribution Programs Fiscal Year (FY) 1995 Financial Statement Audit (ER-FC-96-01)  

SciTech Connect (OSTI)

The charter of the Department of Energy (DOE) Isotope Production and Distribution Program (Isotope Program) covers the production and sale of radioactive and stable isotopes, associated byproducts, surplus materials such as lithium and deuterium, and related isotope services. Services provided include, but are not limited to, irradiation services, target preparation and processing, source encapsulation and other special preparations, analyses, chemical separations, and leasing of stable isotopes for research purposes. Isotope Program products and services are sold worldwide for use in a wide variety of research, development, biomedical, and industrial applications. The Isotope Program reports to the Director of the Office of Nuclear Energy, Science and Technology. The Isotope Program operates under a revolving fund, as established by the Fiscal Year 1990 Energy and Water Appropriations Act (Public Law 101-101). The Fiscal Year 1995 Appropriations Act (Public Law 103-316) modified predecessor acts to allow prices charged for Isotope Program products and services to be based on production costs, market value, the needs of the research community, and other factors. Prices set for small-volume, high-cost isotopes that are needed for research may not achieve full-cost recovery. Isotope Program costs are financed by revenues from the sale of isotopes and associated services and through payments from the isotope support decision unit, which was established in the DOE fiscal year 1995 Energy, Supply, Research, and Development appropriation. The isotope decision unit finances the production and processing of unprofitable isotopes that are vital to the national interest.

NONE

1996-02-12T23:59:59.000Z

352

Sustainability of gamma-ray isotopics evaluation codes  

SciTech Connect (OSTI)

In November 2005, the international workshop 'Gamma Evaluation Codes for Plutonium and Uranium Isotope Abundance Measurements by High-Resolution Gamma Spectrometry: Current Status and Future Challenges' was held in Karlsruhe, Germany. Some of the main issues discussed during the November 2005 meeting were related to concerns voiced by international inspectorate authorities such as the International Atomic Energy Agency (IAEA), the European Atomic Energy Community (EURATOM), and the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) about the standardization and sustainability of gamma-ray isotopic analysis codes that are commonly used during safeguards inspections. A follow-up international workshop was conducted in Oak Ridge, TN in 2008. This workshop was in response to needs expressed by the international safeguards community during the Karlsruhe meeting and recommendations made under Action Sheet 14; a cooperative effort between the U. S. Department of Energy and ABACC. The purpose of the Oak Ridge workshop was to bring code developers and end users together to better understand the capabilities and limitations of the codes; to discuss mechanisms to ensure these codes are sustained and quality tested; and to ensure updates or revisions are performed in a controlled manner. During an Action Sheet 14 meeting held in Rio de Janeiro, Brazil in which the IAEA and EURATOM participated as observers, and in subsequent meetings of the European Safeguards Research and Development Association (ESARDA), all parties agreed that the regional working group initially established under the DOE/ABACC cooperation should be expanded to an international working group. The purpose of the international working group is to provide a forum to exchange information, discuss technical developments, and validate and test the various codes. However, progress to formally establish the working has been slowed by a lack of dedicated funding and competing priorities within the various international organizations. Recently, the ESARDA Nondestructive Assay Working Group established a dedicated website for the International Working Group on Gamma Spectrometry Techniques (1 WG-GST). In this paper, we will explore specific steps that should be taken to strengthen this working group's ability to affect development of a common testing platform and address concerns regarding applicability, sustainability and version control for these important codes.

Vo, Duc [Los Alamos National Laboratory; Koskelo, Markku [AQUILA TECHNOLOGIES; Mcginnis, Brent [ORNL; Wang, Tzu - Feng [LLNL; Peerani, Paolo [IPSC, ISPRA, ITALY; Renha, Geraldo [ABACC, BRAZIL; Dias, Fabio C [NECB, BRAZIL

2010-01-01T23:59:59.000Z

353

Effective interactions and shell model studies of heavy tin isotopes  

E-Print Network [OSTI]

We present results from large-scale shell-model calculations of even and odd tin isotopes from 134Sn to 142}Sn with a shell-model space defined by the 1f7/2,2p3/2,0h9/2,2p1/2,1f5/2,0i13/2 single-particle orbits. An effective two-body interaction based on modern nucleon-nucleon interactions is employed. The shell-model results are in turn analyzed for their pairing content using a generalized seniority approach. Our results indicate that a pairing-model picture captures a great deal of the structure and the correlations of the lowest lying states for even and odd isotopes.

M. P. Kartamyshev; T. Engeland; M. Hjorth-Jensen; E. Osnes

2006-10-05T23:59:59.000Z

354

Development of Halide and Oxy-Halides for Isotopic Separations  

SciTech Connect (OSTI)

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

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

2014-10-01T23:59:59.000Z

355

Descriptions of carbon isotopes within the energy density functional theory  

SciTech Connect (OSTI)

Within the energy density functional (EDF) theory, the structure properties of Carbon isotopes are systematically studied. The shell model calculations are done for both even-A and odd-A nuclei, to study the structure of rich-neutron Carbon isotopes. The EDF theory indicates the single-neutron halo structures in {sup 15}C, {sup 17}C and {sup 19}C, and the two-neutron halo structures in {sup 16}C and {sup 22}C nuclei. It is also found that close to the neutron drip-line, there exist amazing increase in the neutron radii and decrease on the binding energies BE, which are tightly related with the blocking effect and correspondingly the blocking effect plays a significant role in the shell model configurations.

Ismail, Atef [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak, Malaysia and Department of Physics, Al-Azhar University, 71524 Assiut (Egypt); Cheong, Lee Yen; Yahya, Noorhana [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Tammam, M. [Department of Physics, Al-Azhar University, 71524 Assiut (Egypt)

2014-10-24T23:59:59.000Z

356

Metallic beam development for the Facility for Rare Isotope Beam  

SciTech Connect (OSTI)

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

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

2014-02-15T23:59:59.000Z

357

Neutrino scattering off the stable even-even Mo isotopes  

SciTech Connect (OSTI)

Inelastic neutrino-nucleus reaction cross sections are studied focusing on the neutral current processes. Particularly, we investigate the angular and initial neutrino-energy dependence of the differential and integrated cross sections for low and intermediate energies of the incoming neutrino. The nuclear wave functions for the initial and final nuclear states are constructed in the context of the quasi-particle random phase approximation (QRPA) tested on the reproducibility of the low-lying energy spectrum. The results presented here refer to the isotopes Mo{sup 92}, Mo{sup 94}, Mo{sup 96}, Mo{sup 98} and Mo{sup 100}. These isotopes could play a significant role in supernova neutrino detection in addition to their use in double-beta and neutrinoless double-beta decay experiments (e.g. MOON, NEMO III)

Balasi, K. G.; Kosmas, T. S.; Divari, P. C. [Theoretical Physics Section, University of Ioannina, GR 45110 Ioannina (Greece)

2009-11-09T23:59:59.000Z

358

Production and test of isotopically modified Ge detectors for GERDA  

SciTech Connect (OSTI)

The viability of producing BEGe-type detectors from isotopically modified germanium for the GERDA experiment is demonstrated by a complete test of the supply chain. GERDA is built to search for neutrinoless double beta (0v{beta}{beta}) decay of Ge using high-purity germanium detectors made of material enriched in {sup 76}Ge. To reach a sensitivity for 0v{beta}{beta} decay of <1.4 x 10{sup 26} years, new active background suppression techniques are necessary. BEGe detectors enable a capability to efficiently identify and reject background events, while keeping large acceptance of 0v{beta}{beta} decay signal, by using novel pulse shape discrimination (PSD) techniques. The PSD as well as spectroscopic performance of prototype BEGe detectors from isotopically modified Ge was verified by comprehensive testing. (authors)

Budjas, D. [Physik-Dept. E15, Technishe Universitaet Muenchen, James-Franck-Strasse 1, Garching bei Muenchen, D-85748 (Germany)

2011-07-01T23:59:59.000Z

359

Isotope separation with the RICH detector of the AMS Experiment  

E-Print Network [OSTI]

The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station (ISS) in 2008, is a cosmic ray detector with several subsystems, one of which is a proximity focusing Ring Imaging Cherenkov (RICH) detector. This detector will be equipped with a dual radiator (aerogel+NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers and light guides, enabling precise measurements of particle electric charge and velocity. Combining velocity measurements with data on particle rigidity from the AMS Tracker it is possible to obtain a measurement for particle mass, allowing the separation of isotopes. A Monte Carlo simulation of the RICH detector, based on realistic properties measured at ion beam tests, was performed to evaluate isotope separation capabilities. Results for three elements -- H (Z=1), He (Z=2) and Be (Z=4) -- are presented.

Arruda, Luísa; Borges, João; Carmo, Fernando; Gonçalves, Patrícia; Pereira, Rui; Pimenta, Mário

2007-01-01T23:59:59.000Z

360

Oak Ridge Isotope Products and Services - Current and Expected Supply and Demand  

SciTech Connect (OSTI)

Oak Ridge National Laboratory (ORNL) has been a major center of isotope production research, development, and distribution for over 50 years. Currently, the major isotope production activities include (1) the production of transuranium element radioisotopes, including 252 Cf; (2) the production of medical and industrial radioisotopes; (3) maintenance and expansion of the capabilities for production of enriched stable isotopes; and, (4) preparation of a wide range of custom-order chemical and physical forms of isotope products, particularly in accelerator physics research. The recent supply of and demand for isotope products and services in these areas, research and development (R&D), and the capabilities for future supply are described in more detail below. The keys to continuing the supply of these important products and services are the maintenance, improvement, and potential expansion of specialized facilities, including (1) the High Flux Isotope Reactor (HFIR), (2) the Radiochemical Engineering Development Center (REDC) and Radiochemical Development Laboratory (RDL) hot cell facilities, (3) the electromagnetic calutron mass separators and the plasma separation process equipment for isotope enrichment, and (4) the Isotope Research Materials Laboratory (IRML) equipment for preparation of specialized chemical and physical forms of isotope products. The status and plans for these ORNL isotope production facilities are also described below.

Aaron, W.S.; Alexander, C.W.; Cline, R.L.; Collins, E.D.; Klein, J.A.; Knauer, J.B., Jr.; Mirzadeh, S.

1999-08-29T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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.


361

Literature survey of isotopic abundance data for 1987-1989  

SciTech Connect (OSTI)

I have compiled all of the data on isotopic abundance measurements and their variation in nature for the time period since the last General Assembly. Most of the data deals with the variations in the abundances as given by per mil deviations from some standard. As such, they are not of major interest to the Atomic Weights Commission. However, there were some measurements which are of general interest in this list.

Holden, N.E. (Brookhaven National Lab., Upton, NY (USA))

1989-08-09T23:59:59.000Z

362

NOVEL CONCEPTS FOR ISOTOPIC SEPARATION OF 3HE/4HE  

SciTech Connect (OSTI)

The research outlined below established theoretical proof-of-concept using ab initio calculations that {sup 3}He can be separated from {sup 4}He by taking advantage of weak van der Waals interactions with other higher molecular weight rare gases such as xenon. To the best of our knowledge, this is the only suggested method that exploits the physical differences of the isotopes using a chemical interaction.

Roy, L.; Nigg, H.; Watson, H.

2012-09-04T23:59:59.000Z

363

Stable isotopes in late Pennsylvanian brachiopods: stratigraphic and paleoenvironmental implications  

E-Print Network [OSTI]

HORIZON DEEP ~ ?h SHALLOW M~~M MATERIALS AND METHODS Sampling Methods and Criteria Before collecting any samples from the shales, weathered surface material was removed from the sampling intervals. In the Necessity cycle, shale samples were taken... Upper Pennsylvanian sections (Necessity cycle, NC; upper Winchell cycle, UWC; and the Finis Shale, FS) in north-central Texas in order to relate isotopic shifts to paleoenvironment and sea level change. Most samples are from shales that are similar...

Zhang, Chuanlun

1989-01-01T23:59:59.000Z

364

Chromium isotopes as indicators of hexavalent chromium reduction  

SciTech Connect (OSTI)

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

Johnson, Thomas M.

2012-03-20T23:59:59.000Z

365

MAGNESIUM ISOTOPE RATIOS IN {omega} CENTAURI RED GIANTS  

SciTech Connect (OSTI)

We have used the high-resolution observations obtained at the Anglo-Australian Telescope with Ultra-High Resolution Facility (R {approx} 100,000) and at Gemini-S with b-HROS (R {approx} 150,000) to determine magnesium isotope ratios for seven {omega} Cen red giants that cover a range in iron abundance from [Fe/H] = -1.78 to -0.78 dex, and for two red giants in M4 (NGC 6121). The {omega} Cen stars sample both the ''primordial'' (i.e., O-rich, Na- and Al-poor) and the ''extreme'' (O-depleted, Na- and Al-rich) populations in the cluster. The primordial population stars in both {omega} Cen and M4 show ({sup 25}Mg, {sup 26}Mg)/{sup 24}Mg isotopic ratios that are consistent with those found for the primordial population in other globular clusters with similar [Fe/H] values. The isotopic ratios for the {omega} Cen extreme stars are also consistent with those for extreme population stars in other clusters. The results for the extreme population stars studied indicate that the {sup 26}Mg/{sup 24}Mg ratio is highest at intermediate metallicities ([Fe/H] < -1.4 dex), and for the highest [Al/Fe] values. Further, the relative abundance of {sup 26}Mg in the extreme population stars is notably higher than that of {sup 25}Mg, in contrast to model predictions. The {sup 25}Mg/{sup 24}Mg isotopic ratio in fact does not show any obvious dependence on either [Fe/H] or [Al/Fe] nor, intriguingly, any obvious difference between the primordial and extreme population stars.

Da Costa, G. S.; Norris, John E.; Yong, David [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 0200 (Australia)

2013-05-20T23:59:59.000Z

366

Neutrinoless $??$ decay nuclear matrix elements in an isotopic chain  

E-Print Network [OSTI]

We analyze nuclear matrix elements (NME) of neutrinoless double beta decay calculated for the Cadmium isotopes. Energy density functional methods including beyond mean field effects such as symmetry restoration and shape mixing are used. Strong shell effects are found associated to the underlying nuclear structure of the initial and final nuclei. Furthermore, we show that NME for two-neutrino double beta decay evaluated in the closure approximation, $M^{2\

Tomás R. Rodríguez; Gabriel Martínez-Pinedo

2012-10-11T23:59:59.000Z

367

Recent Results for the Ferritics Isotopic Tailoring (FIST) Experiment  

SciTech Connect (OSTI)

An alloy of F82H prepared using the isotope 54 Fe in order to encourage H and He production in a fission reactor has been irradiated in the HFIR JP20 experiment at three temperatures to 7 dpa as TEM disks. Irradiated disks were shear punch tested, examined by TEM, analyzed for He and H content, and compared with previous results in order to quantify irradiation hardening due to transmutation-induced H and He. Hardening due to irradiation is found following irradiation at 300 and 400 C, that is intermediate between that at lower and higher dose, but hardening is negligible following irradiation at 500 C. Microstructural examinations show typical behavior of irradiation as a function of irradiation temperature, with moderate swelling after 400 C irradiation but few bubbles after irradiation at 300 C. Correlations of change in hardening with He and H content show little indication of transmutation-induced hardening, but measured H levels do not agree with predictions and therefore H production and analysis requires further study.

Gelles, David S.; Hamilton, M L.; Oliver, Brian M.; Greenwood, Lawrence R.; Ohnuki, Somei; Shiba, K; Kohno, Yutaka; Kohyama, Akira; Robertson, J P.

2002-12-01T23:59:59.000Z

368

Calculation of Heating Values for the High Flux Isotope Reactor  

SciTech Connect (OSTI)

Calculating the amount of energy released by a fission reaction (fission Q value) and the heating rate distribution in a nuclear reactor is an important part of the safety analysis. However, these calculations can become very complex. One of the codes that can be used for this type of analyses is the Monte Carlo transport code MCNP5. Currently it is impossible to calculate the Q value and heating rate disposition for delayed beta and delayed gamma particles directly from MCNP5. The purpose of this paper is to outline a rigorous method for indirectly calculating the Q values and heating rates in the High Flux Isotope Reactor (HFIR), based on previous similar studies carried out for very high-temperature reactor configurations. This method has been applied in this study to calculate heating rates for the beginning of cycle (BOC) and end-of-cycle (EOC) states of HFIR. In addition, the BOC results obtained for HFIR are compared with corresponding results for the Advanced Test Reactor. The fission Q value for HFIR was calculated as 200.2 MeV for the BOC and 201.3 MeV for the EOC. It was also determined that 95.1% and 95.4% of the heat was deposited within the HFIR fuel plates for the BOC and EOC models, respectively. This methodology can also be used for heating rate calculations for HFIR experiments.

Peterson, Joshua L [ORNL] [ORNL; Ilas, Germina [ORNL] [ORNL

2012-01-01T23:59:59.000Z

369

Experimental Validation of the Multi-Isotope Process Monitor Concept  

SciTech Connect (OSTI)

Researchers from Pacific Northwest National Laboratory, in conjunction with personnel from The Ohio State University, are working to develop a system for monitoring spent nuclear fuel reprocessing facilities on-line, non-destructively, and in near-real-time. This method, known as the Multi-Isotope Process (MIP) Monitor, is based upon the measurement of distribution patterns of a suite of indicator (radioactive) isotopes present within particular process streams. Distribution patterns, monitored on-line by gamma spectrometry, are then compared in near-real-time to patterns representing "normal" process conditions using multivariate pattern recognition software. By targeting gamma-emitting indicator isotopes, the MIP Monitor approach is compatible with the use of small, portable, high-resolution gamma detectors that may be easily deployed throughout the facility. In addition, utilization of a suite of radio-elements, including ones with multiple oxidation states, increases the likelihood that attempts to divert material via process manipulation would be detected. Proof-of-principle modeling exercises simulating changes in acid strength have been completed and the results are promising. Laboratory validation is currently under way and significant results are available. The latest experimental results, along with an overview of the method will be presented.

Orton, Christopher R.; Schwantes, Jon M.; Fraga, Carlos G.; Douglas, Matthew; Christensen, Richard

2010-05-13T23:59:59.000Z

370

Magnesium Isotope Ratios in omega Centauri Red Giants  

E-Print Network [OSTI]

We have used high resolution observations obtained at the AAT with UHRF (R ~ 100,000) and at Gemini-S with b-HROS (R ~ 150,000) to determine magnesium isotope ratios for seven omega Centauri red giants that cover a range in iron abundance from [Fe/H] = --1.78 to --0.78 dex, and for two red giants in M4 (NGC 6121). The omega Centauri stars sample both the "primordial" (i.e., O-rich, Na and Al-poor) and the "extreme" (O-depleted, Na and Al-rich) populations in the cluster. The primordial population stars in both omega Centauri and M4 show (25Mg, 26Mg)/24 Mg isotopic ratios that are consistent with those found for the primordial population in other globular clusters with similar [Fe/H] values. The isotopic ratios for the omega Centauri extreme stars are also consistent with those for extreme population stars in other clusters. The results for the extreme population stars studied indicate that the 26Mg/24Mg ratio is highest at intermediate metallicities ([Fe/H] < --1.4 dex), and for the highest [Al/Fe] values....

Da Costa, G S; Yong, David

2013-01-01T23:59:59.000Z

371

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

SciTech Connect (OSTI)

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

372

A ROBUST ABSOLUTE DETECTION EFFICIENCY CALIBRATION METHOD UTILIZING BETA/GAMMA COINCIDENCE SIGNATURES AND ISOTOPICALLY PURIFIED NEUTRON ACTIVATED RADIOXENON ISOTOPES  

SciTech Connect (OSTI)

Efforts to calibrate the absolute efficiency of gas cell radiations detectors have utilized a number of methodologies which allow adequate calibration but are time consuming and prone to a host of difficult-to-determine uncertainties. A method that extrapolates the total source strength from the measured beta and gamma gated beta coincidence signal was developed in the 1960’s and 1970’s. It has become clear that it is possible to achieve more consistent results across a range of isotopes and a range of activities using this method. Even more compelling is the ease with which this process can be used on routine samples to determine the total activity present in the detector. Additionally, recent advances in the generation of isotopically pure radioxenon samples of Xe-131m, Xe-133, and Xe-135 have allowed these measurement techniques to achieve much better results than would have been possible before when using mixed isotopic radioxenon source. This paper will discuss the beta/gamma absolute detection efficiency technique that utilizes several of the beta-gamma decay signatures to more precisely determine the beta and gamma efficiencies. It will than compare these results with other methods using pure sources of Xe-133, Xe-131m, and Xe-135 and a Xe-133/Xe-133m mix.

McIntyre, Justin I.; Cooper, Matthew W.; Ely, James H.; Haas, Derek A.; Schrom, Brian T.

2012-09-21T23:59:59.000Z

373

Measuring of fissile isotopes partial antineutrino spectra in direct experiment at nuclear reactor  

E-Print Network [OSTI]

The direct measuring method is considered to get nuclear reactor antineutrino spectrum. We suppose to isolate partial spectra of the fissile isotopes by using the method of antineutrino spectrum extraction from the inverse beta decay positron spectrum applied at Rovno experiment. This admits to increase the accuracy of partial antineutrino spectra forming the total nuclear reactor spectrum. It is important for the analysis of the reactor core fuel composition and could be applied for non-proliferation purposes.

V. V. Sinev

2009-02-22T23:59:59.000Z

374

The Multi-Isotope Process (MIP) Monitor Project: FY12 Progress and Accomplishments  

SciTech Connect (OSTI)

The Multi-Isotope Process (MIP) Monitor, being developed at Pacific Northwest National Laboratory (PNNL), provides an efficient approach to monitoring the process conditions in reprocessing facilities in support of the goal of "...(minimization of) the risks of nuclear proliferation and terrorism." The MIP Monitor measures distributions of a suite of indicator (radioactive) isotopes present within product and waste streams of a nuclear reprocessing facility. These indicator isotopes are monitored on-line by gamma spectrometry and compared, in near-real-time, to spectral patterns representing "normal" process conditions using multivariate pattern recognition software. The monitor utilizes this multivariate analysis and gamma spectroscopy of reprocessing streams to detect small changes in the gamma spectrum, which may indicate changes in process conditions. Multivariate analysis methods common in chemometrics, such as principal component analysis (PCA) and partial least squares regression (PLS), act as pattern recognition techniques, which can detect small deviations from the expected, nominal condition. By targeting multiple gamma-emitting indicator isotopes, the MIP Monitor approach is compatible with the use of small, portable, relatively high-resolution gamma detectors that may be easily deployed throughout an existing facility. The automated multivariate analysis can provide a level of data obscurity, giving a built-in information barrier to protect sensitive or proprietary operational data. Proof-of-concept simulations and experiments have been performed in previous years to demonstrate the validity of this tool in a laboratory setting. Development of the MIP Monitor approach continues to evaluate the efficacy of the monitor for automated, real-time or near-real-time application. This report details follow-on research and development efforts sponsored by the U.S. Department of Energy Fuel Cycle Research and Development related to the MIP Monitor for fiscal year 2012 (FY12).

Coble, Jamie B.; Orton, Christopher R.; Jordan, David V.; Schwantes, Jon M.; Bender, Sarah; Dayman, Kenneth J.; Unlu, Kenan; Landsberger, Sheldon

2012-09-27T23:59:59.000Z

375

Helium isotope study of geothermal features in Chile with field and laboratory data  

SciTech Connect (OSTI)

Helium isotope and stable isotope data from the El Tatio, Tinginguirica, Chillan, and Tolhuaca geothermal systems, Chile. Data from this submission are discussed in: Dobson, P.F., Kennedy, B.M., Reich, M., Sanchez, P., and Morata, D. (2013) Effects of volcanism, crustal thickness, and large scale faulting on the He isotope signatures of geothermal systems in Chile. Proceedings, 38th Workshop on Geothermal Reservoir Engineering, Stanford University, Feb. 11-13, 2013

Dobson, Patrick

2013-02-11T23:59:59.000Z

376

E-Print Network 3.0 - americium isotopes Sample Search Results  

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

Summary: fuel. Burning the worst of the radioactive isotopes (plutonium, americium, curium, etc.) to produce... radioactive decay Coupled productiondestruction of 1600...

377

E-Print Network 3.0 - actinide isotopes Sample Search Results  

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

successfully reproduce both the stable solar system isotopic distribution and the stable heavy element... and those predicted by our model. For stars with anomalously high ThEu...

378

E-Print Network 3.0 - accurate sr isotope Sample Search Results  

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

Tbingen Collection: Geosciences 2 Mearon et al. (G18718), p. Cretaceous strontium isotope stratigraphy using Summary: @pangea.stanford.edu. ABSTRACT The strontium...

379

E-Print Network 3.0 - astatine isotopes Sample Search Results  

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

that includes a methane group (CH3) bonded to a halogen element (astatine, bromine... heavy water -- Water in which the molecules contain oxygen and deuterium, an isotope of...

380

DOE and NNSA labs work with CTBTO to reduce medical isotope emissions...  

National Nuclear Security Administration (NNSA)

and NNSA labs work with CTBTO to reduce medical isotope emissions, enhance the effectiveness of nuclear explosion monitoring | National Nuclear Security Administration Facebook...

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

E-Print Network 3.0 - alternative isotope enrichment Sample Search...  

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

of New Mexico Collection: Biology and Medicine ; Environmental Sciences and Ecology 35 Identification of isotopically primitive interplanetary dust particles: A NanoSIMS...

382

E-Print Network 3.0 - anomalous isotopic composition Sample Search...  

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

(Kingston) Collection: Environmental Sciences and Ecology ; Biology and Medicine 32 Identification of isotopically primitive interplanetary dust particles: A NanoSIMS...

383

Domestic production of medical isotope Mo-99 moves a step closer  

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

Mo-99 Domestic production of medical isotope Mo-99 moves a step closer Irradiated uranium fuel has been recycled and reused for molybdenum-99 (Mo-99) production, with...

384

E-Print Network 3.0 - aves carbon isotopes Sample Search Results  

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

J-L. 2006. A new scenario Summary: , Bowling DR, Ehleringer JR. 2003. Seasonal cycle of carbon dioxide and its isotopic composition in an urban... history. ??? Meetings...

385

The Multi-Isotope Process (MIP) Monitor Project: FY13 Final Report...  

Office of Scientific and Technical Information (OSTI)

streams of a nuclear reprocessing facility. These isotopes are monitored online by gamma spectrometry and compared, in near-real-time, to spectral patterns representing "normal"...

386

Stable isotopes of authigenic minerals in variably-saturated fractured tuff  

SciTech Connect (OSTI)

Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ({sup 18}O/{sup 16}O) and carbon ({sup 13}C/{sup 12}C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to result from near-surface isotopic enrichment due to evaporation rather than the effects of rock-water interaction. Oxygen isotope ratios of rock matrix opal samples exhibited an isotopic gradient believed to result from, leaching and reprecipitation of silica at depth. Methods and results can be used to further define primary flowpaths and the movement of water in variably-saturated fractured rock. 71 refs., 23 figs., 3 tabs.

Weber, D.S.; Evans, D.D.

1988-11-01T23:59:59.000Z

387

Stable-Isotope Studies Of Rocks And Secondary Minerals In A Vapor...  

Open Energy Info (EERE)

and calcite whose 18O values record the temperatures and isotopic compositions of fluids prevailing during at least two different episodes of rock-fluid interaction. The first...

388

E-Print Network 3.0 - atom nuclei isotopes Sample Search Results  

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

decay... the name Borromean nuclei. The heaviest neutron rich carbon ... Source: TRIUMF Isotope Separation and ACceleration (ISAC) facility, beta-NMR Group Collection: Physics 27...

389

An experimental study of magnesium-isotope fractionation in chlorophyll-a photosynthesis  

E-Print Network [OSTI]

phosphorylation is a magnesium nuclear spin controlledMagnetic isotope effect of magnesium in phosphoglycerateexchange activities in magnesium chelatase subunits of

Black, J R; Yin, Q Z; Casey, W H

2006-01-01T23:59:59.000Z

390

E-Print Network 3.0 - atomic sorting isotope Sample Search Results  

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

elements of molten basalt by chemical and thermal diffusion... Samples produced in piston cylinder experiments were used to document the thermal isotopic ... Source: Dauphas,...

391

E-Print Network 3.0 - allende meteorite isotopically Sample Search...  

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

of Geophysical Sciences, University of Chicago Collection: Geosciences 31 RARE EARTH ELEMENTS AND OXYGEN ISOTOPES IN ALLENDE CHONDRULES AS EVIDENCE FOR CAI MIXING IN...

392

E-Print Network 3.0 - alkaline earth isotopes Sample Search Results  

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

that laser light could Summary: to alkaline elements, even isotopes of alkaline earth elements do not possess nuclear spin, and therefore do... temper- ature limits achievable by...

393

High Flux Isotope Reactor (HFIR) | U.S. DOE Office of Science...  

Office of Science (SC) Website

(SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities High Flux Isotope Reactor (HFIR) Lujan Neutron Scattering...

394

Carbon isotope ratios of organic compound fractions in oceanic suspended particles  

E-Print Network [OSTI]

Radiocarbon evidence of fossil-carbon cycling in sediments1968), Metabolic fractionation of carbon isotopes in marineof particulate organic carbon using bomb 14 C, Nature,

Hwang, Jeomshik; Druffel, Ellen R. M

2006-01-01T23:59:59.000Z

395

E-Print Network 3.0 - aquifer stable isotopes Sample Search Results  

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

results for: aquifer stable isotopes Page: << < 1 2 3 4 5 > >> 1 Treated domestic wastewater traditionally has been discharged offshore in coastal areas via ocean outfalls. In...

396

E-Print Network 3.0 - achieve isotopic dilution Sample Search...  

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

Matter and Statistical Physics Group Collection: Materials Science 8 EAS 6216 Isotope Geochemistry Fall 2004 MWF 2:05-2:55, EST L1116 Summary: )geochemical tracer 927...

397

Isotope engineering of silicon and diamond for quantum computing and sensing applications  

E-Print Network [OSTI]

Some of the stable isotopes of silicon and carbon have zero nuclear spin, whereas many of the other elements that constitute semiconductors consist entirely of stable isotopes that have nuclear spins. Silicon and diamond crystals composed of nuclear-spin-free stable isotopes (Si-28, Si-30, or C-12) are considered to be ideal host matrixes to place spin quantum bits (qubits) for quntum computing and sensing applications because their coherent properties are not disrupted thanks to the absence of host nuclear spins. The present article describes the state-of-the-art and future perspective of silicon and diamond isotope engineering for development of quantum information processing devices.

Kohei M. Itoh; Hideyuki Watanabe

2014-10-15T23:59:59.000Z

398

A Sr-Isotopic Comparison Between Thermal Waters, Rocks, And Hydrotherm...  

Open Energy Info (EERE)

Sr-Isotopic Comparison Between Thermal Waters, Rocks, And Hydrothermal Calcites, Long Valley Caldera, California Jump to: navigation, search OpenEI Reference LibraryAdd to library...

399

Analyzing Nuclear Fuel Cycles from Isotopic Ratios of Waste Products Applicable to Measurement by Accelerator Mass Spectrometry  

SciTech Connect (OSTI)

An extensive study was conducted to determine isotopic ratios of nuclides in spent fuel that may be utilized to reveal historical characteristics of a nuclear reactor cycle. This forensic information is important to determine the origin of unknown nuclear waste. The distribution of isotopes in waste products provides information about a nuclear fuel cycle, even when the isotopes of uranium and plutonium are removed through chemical processing. Several different reactor cycles of the PWR, BWR, CANDU, and LMFBR were simulated for this work with the ORIGEN-ARP and ORIGEN 2.2 codes. The spent fuel nuclide concentrations of these reactors were analyzed to find the most informative isotopic ratios indicative of irradiation cycle length and reactor design. Special focus was given to long-lived and stable fission products that would be present many years after their creation. For such nuclides, mass spectrometry analysis methods often have better detection limits than classic gamma-ray spectroscopy. The isotopic ratios {sup 151}Sm/{sup 146}Sm, {sup 149}Sm/{sup 146}Sm, and {sup 244}Cm/{sup 246}Cm were found to be good indicators of fuel cycle length and are well suited for analysis by accelerator mass spectroscopy.

Biegalski, S R; Whitney, S M; Buchholz, B

2005-08-24T23:59:59.000Z

400

Nuclear reactor fissile isotopes antineutrino spectra  

E-Print Network [OSTI]

Positron spectrum from inverse beta decay reaction on proton was measured in 1988-1990 as a result of neutrino exploration experiment. The measured spectrum has the largest statistics and lowest energy threshold between other neutrino experiments made that time at nuclear reactors. On base of the positron spectrum the standard antineutrino spectrum for typical reactor fuel composition was restored. In presented analysis the partial spectra forming this standard spectrum were extracted using specific method. They could be used for neutrino experiments data analysis made at any fuel composition of reactor core.

V. Sinev

2012-07-30T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Ultimate Isotope Precision for Carbonates Thermo Scientific  

E-Print Network [OSTI]

vacuum pressure into a cryogenic trapping system. Water and non- condensable gases evolved during phosphorolysis are removed from the CO2 gas phase under high vacuum in the first trap. Prior to transfer into a defined volume. In the microvolume, the dry CO2 is prepared for analysis in a dual microvolume inlet

Lachniet, Matthew S.

402

Differential utilization of allochthonous and autochthonous carbon by aquatic insects of two shrub-steppe desert spring-streams: A stable carbon isotope analysis and critique of the method  

SciTech Connect (OSTI)

The purpose of this study is to assess whether the carbon supporting stream food webs comes principally from terrestrial sources or is produced within the stream. Lacking data to resolve the allochthonous/autochthonous issue with any finality, stream ecologists have alternately postulated that stream carbon was principally autochthonous or principally allochthonous. Others argued that autochthonous and allochthonous carbon resources cannot be separated and that the allochthonous/autochthonous dependence issue is unresolvable. Many investigators have seized upon stable carbon isotopes technology as the tool to resolve the controversy. Unfortunately most investigators have conceded that the results are rarely quantitative and that the qualitative relationships are ambiguous. This study points out the fallacies of trying to conjure single isotopic values for either allochthonous or autochthonous carbon. It suggests that stable carbon isotope technology is not reliable in establishing specific consumer/food source relations and that it is not suitable for assessing allochthonous/autochthonous carbon dependence in freshwater streams.

Mize, A.L. [Old Dominion Univ., Norfolk, VA (United States)

1993-06-01T23:59:59.000Z

403

Determination of Light Water Reactor Fuel Burnup with the Isotope Ratio Method  

SciTech Connect (OSTI)

For the current project to demonstrate that isotope ratio measurements can be extended to zirconium alloys used in LWR fuel assemblies we report new analyses on irradiated samples obtained from a reactor. Zirconium alloys are used for structural elements of fuel assemblies and for the fuel element cladding. This report covers new measurements done on irradiated and unirradiated zirconium alloys, Unirradiated zircaloy samples serve as reference samples and indicate starting values or natural values for the Ti isotope ratio measured. New measurements of irradiated samples include results for 3 samples provided by AREVA. New results indicate: 1. Titanium isotope ratios were measured again in unirradiated samples to obtain reference or starting values at the same time irradiated samples were analyzed. In particular, 49Ti/48Ti ratios were indistinguishably close to values determined several months earlier and to expected natural values. 2. 49Ti/48Ti ratios were measured in 3 irradiated samples thus far, and demonstrate marked departures from natural or initial ratios, well beyond analytical uncertainty, and the ratios vary with reported fluence values. The irradiated samples appear to have significant surface contamination or radiation damage which required more time for SIMS analyses. 3. Other activated impurity elements still limit the sample size for SIMS analysis of irradiated samples. The sub-samples chosen for SIMS analysis, although smaller than optimal, were still analyzed successfully without violating the conditions of the applicable Radiological Work Permit

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

2007-11-01T23:59:59.000Z

404

Final Progress Report: Isotope Identification Algorithm for Rapid and Accurate Determination of Radioisotopes Feasibility Study  

SciTech Connect (OSTI)

This is the final report of the project titled, 'Isotope Identification Algorithm for Rapid and Accurate Determination of Radioisotopes,' PMIS project number LA10-HUMANID-PD03. The goal of the work was to demonstrate principles of emulating a human analysis approach towards the data collected using radiation isotope identification devices (RIIDs). It summarizes work performed over the FY10 time period. The goal of the work was to demonstrate principles of emulating a human analysis approach towards the data collected using radiation isotope identification devices (RIIDs). Human analysts begin analyzing a spectrum based on features in the spectrum - lines and shapes that are present in a given spectrum. The proposed work was to carry out a feasibility study that will pick out all gamma ray peaks and other features such as Compton edges, bremsstrahlung, presence/absence of shielding and presence of neutrons and escape peaks. Ultimately success of this feasibility study will allow us to collectively explain identified features and form a realistic scenario that produced a given spectrum in the future. We wanted to develop and demonstrate machine learning algorithms that will qualitatively enhance the automated identification capabilities of portable radiological sensors that are currently being used in the field.

Rawool-Sullivan, Mohini [Los Alamos National Laboratory; Bounds, John Alan [Los Alamos National Laboratory; Brumby, Steven P. [Los Alamos National Laboratory; Prasad, Lakshman [Los Alamos National Laboratory; Sullivan, John P. [Los Alamos National Laboratory

2012-04-30T23:59:59.000Z

405

High flux isotope reactor cold source preconceptual design study report  

SciTech Connect (OSTI)

In February 1995, the deputy director of Oak Ridge National Laboratory (ORNL) formed a group to examine the need for upgrades to the High Flux Isotope Reactor (HFIR) system in light of the cancellation of the Advanced Neutron Source Project. One of the major findings of this study was that there was an immediate need for the installation of a cold neutron source facility in the HFIR complex. The anticipated cold source will consist of a cryogenic LH{sub 2} moderator plug, a cryogenic pump system, a refrigerator that uses helium gas as a refrigerant, a heat exchanger to interface the refrigerant with the hydrogen loop, liquid hydrogen transfer lines, a gas handling system that includes vacuum lines, and an instrumentation and control system to provide constant system status monitoring and to maintain system stability. The scope of this project includes the development, design, safety analysis, procurement/fabrication, testing, and installation of all of the components necessary to produce a working cold source within an existing HFIR beam tube. This project will also include those activities necessary to transport the cold neutron beam to the front face of the present HFIR beam room. The cold source project has been divided into four phases: (1) preconceptual, (2) conceptual design and research and development (R and D), (3) detailed design and procurement, and (4) installation and operation. This report marks the conclusion of the preconceptual phase and establishes the concept feasibility. The information presented includes the project scope, the preliminary design requirements, the preliminary cost and schedule, the preliminary performance data, and an outline of the various plans for completing the project.

Selby, D.L.; Bucholz, J.A.; Burnette, S.E. [and others

1995-12-01T23:59:59.000Z

406

Scoping Inventory Calculations for the Rare Isotope Accelerator  

SciTech Connect (OSTI)

This document is a report on our activities in FY03 exploring nuclear safety and hazard analysis issues relevant to the Rare Isotope Accelerator (RIA). It is not clear whether DOE will classify the RIA as an accelerator facility subject to the accelerator-specific safety requirements of DOE Order 420.2A or as a nonreactor nuclear facility subject to the requirements of 10 CFR 830. The final outcome of this issue will have significant impact on the construction and operation of the facility and the quality assurance requirements for items or services that may affect nuclear safety. The resolution of this issue will be an important earlier decision for the RIA project team and will require early consultation with the appropriate DOE authorities. For nuclear facilities, facility hazard classification depends on the inventory of releasable radionuclides; therefore, some simplistic, scoping inventory calculations for some assumed targets and beams are done to estimate the hazard category of RIA if it is declared a nuclear facility. These calculations show that for the scenarios analyzed, RIA would produce sufficient quantities of radionuclides to be classified as a Category 3 nuclear facility. Over the lifetime of RIA operations, it may be possible to build up Category 2 quantities of {sup 227}Ac and {sup 228}Th. A storage building, separate from the driver, target, and experimental buildings, used to store and isolate accumulated targets and other hardware, can mitigate the potential impact on RIA. The more onerous requirements of Category 2 facilities would only be imposed on the storage facility and not on the rest of the RIA facilities. Some of the differences in a category 2 and category 3 facility are discussed in Appendix 1.

Ahle, L E; Boles, J L

2003-07-25T23:59:59.000Z

407

EVIDENCE FOR MAGNESIUM ISOTOPE HETEROGENEITY IN THE SOLAR PROTOPLANETARY DISK  

SciTech Connect (OSTI)

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

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

2011-07-10T23:59:59.000Z

408

Stable water isotope simulation by current land-surface schemes:Results of IPILPS phase 1  

SciTech Connect (OSTI)

Phase 1 of isotopes in the Project for Intercomparison of Land-surface Parameterization Schemes (iPILPS) compares the simulation of two stable water isotopologues ({sup 1}H{sub 2} {sup 18}O and {sup 1}H{sup 2}H{sup 16}O) at the land-atmosphere interface. The simulations are off-line, with forcing from an isotopically enabled regional model for three locations selected to offer contrasting climates and ecotypes: an evergreen tropical forest, a sclerophyll eucalypt forest and a mixed deciduous wood. Here we report on the experimental framework, the quality control undertaken on the simulation results and the method of intercomparisons employed. The small number of available isotopically-enabled land-surface schemes (ILSSs) limits the drawing of strong conclusions but, despite this, there is shown to be benefit in undertaking this type of isotopic intercomparison. Although validation of isotopic simulations at the land surface must await more, and much more complete, observational campaigns, we find that the empirically-based Craig-Gordon parameterization (of isotopic fractionation during evaporation) gives adequately realistic isotopic simulations when incorporated in a wide range of land-surface codes. By introducing two new tools for understanding isotopic variability from the land surface, the Isotope Transfer Function and the iPILPS plot, we show that different hydrological parameterizations cause very different isotopic responses. We show that ILSS-simulated isotopic equilibrium is independent of the total water and energy budget (with respect to both equilibration time and state), but interestingly the partitioning of available energy and water is a function of the models' complexity.

Henderson-Sellers, A.; Fischer, M.; Aleinov, I.; McGuffie, K.; Riley, W.J.; Schmidt, G.A.; Sturm, K.; Yoshimura, K.; Irannejad, P.

2005-10-31T23:59:59.000Z

409

Consistency test of neutrinoless double beta decay with one isotope  

E-Print Network [OSTI]

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

Michael Duerr; Manfred Lindner; Kai Zuber

2011-11-17T23:59:59.000Z

410

Isotopic equilibration of carbon monoxide catalyzed by supported ruthenium  

SciTech Connect (OSTI)

Isotopic equilibration of carbon monoxide catalyzed by supported ruthenium was studied with oxygen-18 and carbon-13 labeled carbon monoxide in the presence and absence of hydrogen. The results showed that carbon monoxide was present on commercial alumina-supported ruthenium in a reactive undissociated form at 373/sup 0/K; that it adsorbed as a single carbonyl and in a geminal dicarbonyl form; and that hydrogen inhibited the exchange reaction by competitive adsorption and by stabilizing the carbonyl bond. The results elucidate the carbon monoxide methanation and Fischer-Tropsch reactions on this catalyst.

Bossi, A. (Cent. Ric. Novara); Zanderighi, L.; Carnisio, G.; Garbassi, F.; Giunchi, G.; Petrini, G.

1980-09-01T23:59:59.000Z

411

Direct measurements of neutron capture on radioactive isotopes  

E-Print Network [OSTI]

We simulated the response of a 4p calorimetric g-detector array to decays of radioactive isotopes on the s-process path. The GEANT 3.21 simulation package was used. The main table contains estimates on the maximum sample size and required neutron flux based on the latest available neutron capture cross section at 30 keV. The results are intended to be used to estimate the feasibility of neutron capture measurements with 4p arrays using the time of flight technique.

A. Couture; R. Reifarth

2009-09-30T23:59:59.000Z

412

Consistency test of neutrinoless double beta decay with one isotope  

SciTech Connect (OSTI)

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

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

2011-11-01T23:59:59.000Z

413

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

E-Print Network [OSTI]

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

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

2008-02-02T23:59:59.000Z

414

Determination of the theoretical feasibility for the transmutation of europium isotopes from high flux isotope reactor control cylinders  

SciTech Connect (OSTI)

The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) is a 100 MWth light-water research reactor designed and built in the 1960s primarily for the production of transuranic isotopes. The HFIR is equipped with two concentric cylindrical blade assemblies, known as control cylinders, that are used to control reactor power. These control cylinders, which become highly radioactive from neutron exposure, are periodically replaced as part of the normal operation of the reactor. The highly radioactive region of the control cylinders is composed of europium oxide in an aluminum matrix. The spent HFIR control cylinders have historically been emplaced in the ORNL Waste Area Grouping (WAG) 6. The control cylinders pose a potential radiological hazard due to the long lived radiotoxic europium isotopes {sup 152}Eu, {sup 154}Eu, and {sup 155}Eu. In a 1991 health evaluation of WAG 6 (ERD 1991) it was shown that these cylinders were a major component of the total radioactivity in WAG 6 and posed a potential exposure hazard to the public in some of the postulated assessment scenarios. These health evaluations, though preliminary and conservative in nature, illustrate the incentive to investigate methods for permanent destruction of the europium radionuclides. When the cost of removing the control cylinders from WAG 6, performing chemical separations and irradiating the material in HFIR are factored in, the option of leaving the control cylinders in place for decay must be considered. Other options, such as construction of an engineered barrier around the disposal silos to reduce the chance of migration, should also be analyzed.

Elam, K.R.; Reich, W.J.

1995-09-01T23:59:59.000Z

415

Lithium isotopes in global mid-ocean ridge basalts Paul B. Tomascak a,*, Charles H. Langmuir b  

E-Print Network [OSTI]

Lithium isotopes in global mid-ocean ridge basalts Paul B. Tomascak a,*, Charles H. Langmuir b January 2008 Abstract The lithium isotope compositions of 30 well-characterized samples of glassy lavas

Langmuir, Charles H.

416

Evolution of Anthropogenic Pb and Pb isotopes in the deep North Atlantic Ocean and the Indian Ocean  

E-Print Network [OSTI]

Pb and Pb isotopes in the ocean have varied on decadal to centennial time scales due to anthropogenic Pb inputs. Thus, tracing the temporal variation of Pb and Pb isotopes in the ocean provides information on the major ...

Lee, Jong-Mi, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

417

Test results of a new detector system for gamma ray isotopic measurements  

SciTech Connect (OSTI)

A new type of gamma-ray detector system for isotopic measurements has been developed. This new system, a ``Duo detector`` array, consists of two intrinsic germanium detectors, a planar followed by a coaxial mounted on the same axis within a single cryostat assembly. This configuration allows the isotopic analysis system to take advantage of spectral data results that are collected simultaneously from different gamma-ray energy regimes. Princeton Gamma Tech (PGT) produced several prototypes of this Duo detector array which were then tested by Rocky Flats personnel until the design was optimized. An application for this detector design is in automated, roboticized NDA systems such as those being developed at the Los Alamos TA-55 Plutonium Facility. The Duo detector design reduces the space necessary for the isotopic instrument by a factor of two (only one liquid nitrogen dewar is needed), and also reduces the complexity of the mechanical systems and controlling software. Data will be presented on measurements of nuclear material with a Duo detector for a wide variety of matrices. Results indicate that the maximum count rate can be increased up to 100,000 counts per second yet maintaining excellent resolution and energy rate product.

Malcom, J.E.; Bonner, C.A.; Hurd, J.R. [Los Alamos National Lab., NM (United States); Fleissner, [EG and G Rocky Flats, Inc., Golden, CO (United States)

1993-08-01T23:59:59.000Z

418

Measurement of lithium isotope ratios by quadrupole-ICP-MS: application to seawater and natural carbonates  

E-Print Network [OSTI]

Measurement of lithium isotope ratios by quadrupole-ICP-MS: application to seawater and natural method for lithium isotope ratio (7 Li/6 Li) determinations with low total lithium consumption ( lithium from all matrix elements using small volume resin (2 ml/3.4 meq AG 50W-X8) and low volume elution

Weston, Ken

419

Lead isotopes in sediments of the Loire River (France): natural versus anthropogenic origin  

E-Print Network [OSTI]

Lead isotopes in sediments of the Loire River (France): natural versus anthropogenic origin Philippe Négrel Emmanuelle Petelet-Giraud BRGM, Orléans, France Sediments along the Loire River (central France) were investigated by means of lead isotopes determined on the labile sediment fraction, or acid

Paris-Sud XI, Université de

420

Hf isotope compositions of northern Luzon arc lavas suggest involvement of pelagic sediments in their source  

E-Print Network [OSTI]

1 Hf isotope compositions of northern Luzon arc lavas suggest involvement of pelagic sediments passing through the data intersect fields for depleted mantle and pelagic sediments suggesting. The relationship between Nd and Hf isotopic compositions in the Luzon volcanics show that the type of sediment

Boyer, Edmond

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Lithium isotopic composition and concentration of the deep continental crust Fang-Zhen Teng a,  

E-Print Network [OSTI]

Lithium isotopic composition and concentration of the deep continental crust Fang-Zhen Teng a April 2008 Accepted 5 June 2008 Editor: B. Bourdon Keywords: Lithium Isotope fractionation Deep. Lithium concentrations of granulite xenoliths also vary widely (0.5 to 21 ppm) and are, on average, lower

Mcdonough, William F.

422

Lithium isotopes in island arc geothermal systems: Guadeloupe, Martinique (French West Indies) and experimental approach  

E-Print Network [OSTI]

Lithium isotopes in island arc geothermal systems: Guadeloupe, Martinique (French West Indies and the Diamant areas). The lithium isotopic signatures of the geothermal fluids collected from deep reservoirs during formation of Li- bearing secondary minerals by the uptake of lithium into the alteration minerals

Boyer, Edmond

423

Limited lithium isotopic fractionation during progressive metamorphic dehydration in metapelites: A case study  

E-Print Network [OSTI]

Limited lithium isotopic fractionation during progressive metamorphic dehydration in metapelites-zone metamorphism far removed from the pluton to partially melted rocks adjacent to the pluton. Lithium on the aureole scale. Published by Elsevier B.V. Keywords: Lithium; Isotope fractionation; Metamorphic

Mcdonough, William F.

424

Strontium isotopes and nutrient sourcing in a semi-arid woodland Amanda C. Reynolds a  

E-Print Network [OSTI]

Strontium isotopes and nutrient sourcing in a semi-arid woodland Amanda C. Reynolds a , Jay Quade b in revised form 7 June 2012 Accepted 21 June 2012 Available online xxxx Keywords: Strontium isotopes Nutrient Malpais National Monument (EMNM), New Mexico provide an ideal set- ting to examine strontium, and hence

425

Carbon isotope ratio of Cenozoic CO2: A comparative evaluation of available geochemical proxies  

E-Print Network [OSTI]

Click Here for Full Article Carbon isotope ratio of Cenozoic CO2: A comparative evaluation 2009; revised 16 February 2010; accepted 1 March 2010; published 17 July 2010. [1] The carbon isotope that these factors act to offset one another. Our reconstruction suggests that Cenozoic d13 CCO2 averaged -6.1 ± 0

Tipple, Brett

426

Environmental assessment for the relocation and storage of isotopic heat sources, Hanford Site, Richland, Washington  

SciTech Connect (OSTI)

As part of a bilateral agreement between the Federal Minister for Research and Technology of the Federal Republic of Germany (FRG) and the DOE, Pacific Northwest National Laboratory (PNNL) developed processes for the treatment and immobilization of high-level radioactive waste. One element of this bilateral agreement was the production of sealed isotopic heat sources. During the mid-1980s, 30 sealed isotopic heat sources were manufactured. The sources contain a total of approximately 8.3 million curies consisting predominantly of cesium-137 and strontium-90 with trace amounts of transuranic contamination. Currently, the sources are stored in A-Cell of the 324 Building. Intense radiation fields from the sources are causing the cell windows and equipment to deteriorate. Originally, it was not intended to store the isotopic heat sources for this length of time in A-cell. The 34 isotopic heat sources are classified as remote handled transuranic wastes. Thirty-one of the isotopic heat sources are sealed, and seals on the three remaining isotopic heat sources have not been verified. However, a decision has been made to place the remaining three isotopic heat sources in the CASTOR cask(s). The Washington State Department of Health (WDOH) has concurred that isotopic heat sources with verified seals or those placed into CASTOR cask(s) can be considered sealed (no potential to emit radioactive air emissions) and are exempt from WAC Chapter 246-247, Radiation Protection-Air Emissions.

NONE

1997-06-01T23:59:59.000Z

427

Late Quaternary variability of sedimentary nitrogen isotopes in the eastern South Pacific Ocean  

E-Print Network [OSTI]

Late Quaternary variability of sedimentary nitrogen isotopes in the eastern South Pacific Ocean), Late Quaternary variability of sedimentary nitrogen isotopes in the eastern South Pacific Ocean) in the water columns of the Arabian Sea (AS) and the eastern North and South Pacific oceans (ENP; ESP) holds

Demouchy, Sylvie

428

Hydrogen isotope fractionation in freshwater and marine algae: II. Temperature and nitrogen limited growth rate effects  

E-Print Network [OSTI]

Hydrogen isotope fractionation in freshwater and marine algae: II. Temperature and nitrogen limited isotope fractionation in freshwater algae: I. Variations among lipids and spe- cies. Organic Geochemistry. Two species of freshwater green algae, Eudorina unicocca and Volvox aureus, were grown in batch

Sachs, Julian P.

429

Isotope systematics of ore-bearing granites and host rocks of the Orlovka-Spokoinoe mining  

E-Print Network [OSTI]

Isotope systematics of ore-bearing granites and host rocks of the Orlovka-Spokoinoe mining district and Spokoinoe granite massifs and their host rocks in the Orlovka- Spokoinoe mining district, Eastern Transbaikalia, Russia. Pb isotope analyses indicate one common Pb source for all three granite massifs

Siebel, Wolfgang

430

Behaviour of lithium and its isotopes during weathering in1 the Mackenzie Basin, Canada2  

E-Print Network [OSTI]

1 Behaviour of lithium and its isotopes during weathering in1 the Mackenzie Basin, Canada2 3 Romain and lithium concentrations found in the dissolved load of the Mackenzie rivers suggests31 that precipitation fluxes in the Mackenzie River Basin.40 41 Keywords: lithium isotopes, river waters, silicate weathering

431

EIS-0136: Special Isotope Separation Project Idaho National Engineering Laboratory, Idaho Falls, Idaho  

Broader source: Energy.gov [DOE]

The U.S. Department of Energy developed this EIS to provide environmental input to the decision to construct the Special Isotope Separation Project which would allow for the processing of existing fuel-grade plutonium into weapons-grade plutonium using the Atomic Laser Isotope Separation process.

432

Ca and 87/86 Sr isotopes as tracers of silicate weathering in small  

E-Print Network [OSTI]

44/40 Ca and 87/86 Sr isotopes as tracers of silicate weathering in small catchments of the Massif, Laboratory Division, Orléans, France 2 U.S. Geological Survey, Water Resources Division, Menlo Park, CA 94025).Measurements of 44/40 Ca isotope ratios (44/40 Ca measured by the double spike method on TIMS and normalized

Paris-Sud XI, Université de

433

Ca isotopes in carbonate sediment and pore fluid from ODP Site 807A: The Ca2+  

E-Print Network [OSTI]

Ca isotopes in carbonate sediment and pore fluid from ODP Site 807A: The Ca2+ (aq, Berkeley, CA 94720-4767, USA b Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 2007 Abstract The calcium isotopic compositions (d44 Ca) of 30 high-purity nannofossil ooze and chalk

Fantle, Matthew

434

Constraint of the CO2 rise by new atmospheric carbon isotopic measurements during the last deglaciation  

E-Print Network [OSTI]

Click Here for Full Article Constraint of the CO2 rise by new atmospheric carbon isotopic increase of atmospheric carbon dioxide (CO2) during the last glacialinterglacial climatic transition remain debated. We analyzed the parallel evolution of CO2 and its stable carbon isotopic ratio (d13 CO2

Chappellaz, Jérôme

435

Ice-free conditions in Sweden during Marine Oxygen Isotope Stage 3? BARBARA WOHLFARTH  

E-Print Network [OSTI]

Ice-free conditions in Sweden during Marine Oxygen Isotope Stage 3? BARBARA WOHLFARTH BOREAS Wohlfarth, B. 2010 (April): Ice-free conditions in Sweden during Marine Oxygen Isotope Stage 3? Boreas, Vol dates for Sweden older than the Last Glacial Maximum ice advance were eval- uated. Acceptable 14 C dates

Wohlfarth, Barbara

436

Fuel Source Isotopic Tailoring Impact on ITER Design, Operation and Safety  

E-Print Network [OSTI]

1 Fuel Source Isotopic Tailoring and Its Impact on ITER Design, Operation and Safety M. J. Gouge, W. The isotopic tailoring concept consists of utilizing a tritium-rich pellet source for core fueling and a deuterium- rich gas source for edge fueling. Because of the improved particle confinement associated

437

Carbon isotope evidence for recent climate-related enhancement of CO2 assimilation and peat accumulation  

E-Print Network [OSTI]

Carbon isotope evidence for recent climate-related enhancement of CO2 assimilation and peat change. In this study, peat cores up to 2 m in depth from four moss banks on Signy Island were used included radiocarbon dating (to determine peat accumulation rates) and stable carbon isotope composition

438

Thorium isotopes in the western Mediterranean Sea: an insight into the marine particle dynamics  

E-Print Network [OSTI]

Thorium isotopes in the western Mediterranean Sea: an insight into the marine particle dynamics M rights reserved. Keywords: thorium; isotopes; sea water; particles; sedimentation; Mediterranean Sea 1 physical, chemical and biological processes and sometimes non-steady-state condi- tions [1^4]. Thorium

Coppola, Laurent

439

Alpha-emitting isotopes and chromium in a coastal California aquifer Jill N. Densmore a,  

E-Print Network [OSTI]

.epa.gov/drink/contaminants/#List, accessed December 3, 2013). Understanding the chemistry and distribution of isotopes within the uranium) of 15 pCi/L, when adjusted for uranium activity; there is concern that new wells in the area may exceed-dependent water-quality data collected from the wells in 2011 (with analyses for isotopes within the uranium

440

Environmental isotope investigation of groundwater flow in the Honey Lake Basin, California and Nevada  

SciTech Connect (OSTI)

The hydrology of Honey Lake Basin was studied using environmental isotope measurements of approximately 130 water samples collected during 1995 and 1996. The principal analytical methods included hydrogen, oxygen and carbon stable isotope ratio measurements, radiocarbon and tritium dating, and measurements of dissolved noble gas abundances.

Rose, T.P.; Davisson, M.L.; Hudson, G.B.; Varian, A.R.

1997-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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

Oxygen Isotope Effects as Probes of Electron Transfer Mechanisms and Structures of  

E-Print Network [OSTI]

Oxygen Isotope Effects as Probes of Electron Transfer Mechanisms and Structures of Activated O2, Maryland 21218 RECEIVED ON JULY 26, 2008 C O N S P E C T U S Competitively determined oxygen (18 O) isotope effects can be power- ful probes of chemical and biological transformations involving molec- ular oxygen

Roth, Justine P.

442

15N2 formation and fast oxygen isotope exchange during pulsed...  

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

N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOxCeO2. 15N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOx...

443

Project EARTH-11-DP1: Exploring early solar system processes using Cr isotopes  

E-Print Network [OSTI]

Project EARTH-11-DP1: Exploring early solar system processes using Cr isotopes Supervisors: Dr D Porcelli & Dr K Amor Various isotope methods have been recently developed to explore the conditions in the early solar system and the processes that have led to the formation of the terrestrial planets. Stable

Henderson, Gideon

444

ENRICHED STABLE ISOTOPE TARGET PREPARATION AT THE OAK RIDGE NATIONAL LABORATORY  

SciTech Connect (OSTI)

Since the 1960s the Department of Energy (DOE) Isotope Program, through the Isotope Development Group at the Oak Ridge National Laboratory, has been developing and supplying, among other things, enriched stable isotope targets for nuclear research around the world. This group also maintains and distributes the DOE inventory of enriched stable isotopes. Chemical and pyrochemical techniques are used to prepare enriched stable isotopes from this inventory in the desired chemical form. Metallurgical, ceramic, or vacuum processing methods are then used to prepare the isotopes in a wide range of physical forms from thin films, foils, and coatings to large fabricated shapes to meet the needs of experimenters. Significant characterization capabilities are also available to assist in the preparation and evaluation of these custom materials. This work is part of the DOE Isotope Program, which recently transferred to the Office of Nuclear Physics, DOE Office of Science, resulting in a stronger emphasis on enabling R&D. This presentation will focus on the custom preparation of enriched stable isotope targets and other research materials.

Aaron, W Scott [ORNL] [ORNL; Zevenbergen, Lee [ORNL] [ORNL

2013-01-01T23:59:59.000Z

445

Mollusc shell periostracum as an alternative to tissue in isotopic studies  

E-Print Network [OSTI]

such as mollusc shells, however, are often abundant because of their ease of storage. We used stable isotope ratios of carbon and nitrogen to determine if there was a relationship between the isotopic composition of the periostracum of the shell and soft body...

Delong, Michael D.; Thorp, James H.

2009-06-01T23:59:59.000Z

446

Experimental determination of equilibrium nickel isotope fractionation between metal and silicate from 500 C  

E-Print Network [OSTI]

Experimental determination of equilibrium nickel isotope fractionation between metal and silicate.04& between equilibrated bulk silicate Earth and chondrites, indicating that Ni isotopes are not likely- lation process involving a well-mixed silicate reservoir. Ã? 2012 Elsevier Ltd. All rights reserved. 1

Manning, Craig

447

Lead isotopes behavior in the fumarolic environment of the Piton de la Fournaise volcano (Reunion Island)  

E-Print Network [OSTI]

significantly outside the field of lavas. The iso- topic shift is ascribed to leaching ubiquitous unradiogenic phases (e.g., sulfides) by acidic gas condensates. The similarity in Pb isotope signature between lavas isotopes resulting from volatilization and condensation processes is smaller than the precision of Pb iso

448

Vegetation succession and carbon sequestration in a coastal wetland in northwest Florida: Evidence from carbon isotopes  

E-Print Network [OSTI]

Vegetation succession and carbon sequestration in a coastal wetland in northwest Florida: Evidence from carbon isotopes Yonghoon Choi and Yang Wang Department of Geological Sciences, Florida State. Measurements of stable carbon isotopic ratios as well as carbon (C), nitrogen (N), and phosphorus (P) contents

Wang, Yang

449

A HEAVY ISOTOPE IN A SOLID DRIFTS DOWN A THERMAL ENERGY GRADIENT  

E-Print Network [OSTI]

183 A HEAVY ISOTOPE IN A SOLID DRIFTS DOWN A THERMAL ENERGY GRADIENT R. V. HESKETH CEGB Berkeley, and indeed, related to the second law ; to the familar statement that thermal energy diffuses from hot to cold we merely add the corollary even when the carriers of thermal energy are isotopic defects

Paris-Sud XI, Université de

450

Natural thorium isotopes in marine sediment core off Labuan port  

SciTech Connect (OSTI)

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

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

2014-02-12T23:59:59.000Z

451

Retention of Hydrogen Isotopes in Neutron Irradiated Tungsten  

SciTech Connect (OSTI)

To investigate the effects of neutron irradiation on hydrogen isotope retention in tungsten, disk-type specimens of pure tungsten were irradiated in the High Flux Isotope Reactor in Oak Ridge National Laboratory followed by exposure to high flux deuterium (D) plasma in Idaho National Laboratory. The results obtained for low dose n-irradiated specimens (0.025 dpa for tungsten) are reviewed in this paper. Irradiation at coolant temperature of the reactor (around 50 degrees C) resulted in the formation of strong trapping sites for D atoms. The concentrations of D in n-irradiated specimens were ranging from 0.1 to 0.4 mol% after exposure to D plasma at 200 and 500 degrees C and significantly higher than those in non-irradiated specimens because of D-trapping by radiation defects. Deep penetration of D up to a depth of 50-100 µm was observed at 500 degrees C. Release of D in subsequent thermal desorption measurements continued up to 900 degrees C. These results were compared with the behaviour of D in ion-irradiated tungsten, and distinctive features of n-irradiation were discussed.

Yuji Hatano; Masashi Shimada; Yasuhisa Oya; Guoping Cao; Makoto Kobayashi; Masanori Hara; Brad J. Merrill; Kenji Okuno; Mikhail A. Sokolov; Yutai Katoh

2013-03-01T23:59:59.000Z

452

Couplings between dipole and quadrupole vibrations in tin isotopes  

E-Print Network [OSTI]

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

Cédric Simenel; Philippe Chomaz

2009-12-11T23:59:59.000Z

453

Beta-delayed Neutron Spectroscopy of $^{130-132}$Cd Isotopes with the ISOLDE Decay Station and the VANDLE array  

E-Print Network [OSTI]

Beta-delayed Neutron Spectroscopy of $^{130-132}$Cd Isotopes with the ISOLDE Decay Station and the VANDLE array

Madurga Flores, Miguel; Kolos, K; Bardayan, D; Borge, M J G; Brewer, N T; Cocolios, T E; Cizewski, J A; Dillman, I; Fijalkowska, A; Fraile, L M; Gross, C J; Goetz, K C; Ilyushkin, S V; Mazzocchi, C; Manning, B; Miernik, K; Miller, D; Paulauskas, S V; Peters, W A; Ratkiewicz, A; Rykaczewski, K P; Taylor, S; Tengblad, O; Sotty, C; De Witte, H; Xiao, Y; CERN. Geneva. ISOLDE and neutron Time-of-Flight Experiments Committee; INTC

2014-01-01T23:59:59.000Z

454

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

SciTech Connect (OSTI)

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

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

1987-01-01T23:59:59.000Z

455

Mass-dependent and -independent fractionation of isotopes in Ni and Pb chelate complex formation reactions  

SciTech Connect (OSTI)

Mass independent fractionation (MIF) has been a very interesting topic in the field of inorganic isotope chemistry, in particular, geo- and cosmo- chemistry. In the present work, we studied the isotope fractionation of Ni(II) and Pb(II) ions in complex formation with chelating reagent EDTA. To obtain clear results on the mass dependence of the isotope fractionation, we have conducted long-distance ion exchange chromatography of Ni(II) and Pb(II), using chelate complex reagent EDTA. The results apparently show that the isotope fractionation in Ni complex formation system is governed by the mass dependent rule. On the other hand the isotope fractionation in the Pb complex system is governed by the mass independent rule or the nuclear volume effect.

Nomura, Masao; Kudo, Takashi; Adachi, Atsuhiko; Aida, Masao; Fujii, Yasuhiko [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, O-okayama Meguroku, Tokyo, 152-8550 (Japan)] [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, O-okayama Meguroku, Tokyo, 152-8550 (Japan)

2013-11-13T23:59:59.000Z

456

Significance of Isotopically Labile Organic Hydrogen in Thermal Maturation of Organic Matter  

SciTech Connect (OSTI)

Isotopically labile organic hydrogen in fossil fuels occupies chemical positions that participate in isotopic exchange and in chemical reactions during thermal maturation from kerogen to bitumen, oil and gas. Carbon-bound organic hydrogen is isotopically far less exchangeable than hydrogen bound to nitrogen, oxygen, or sulfur. We explore why organic hydrogen isotope ratios express a relationship with organic nitrogen isotope ratios in kerogen at low to moderate maturity. We develop and apply new techniques to utilize organic D/H ratios in organic matter fractions and on a molecular level as tools for exploration for fossil fuels and for paleoenvironmental research. The scope of our samples includes naturally and artificially matured substrates, such as coal, shale, oil and gas.

Arndt Schimmelmann; Maria Mastalerz

2010-03-30T23:59:59.000Z

457

Simulation of the Stable Water Isotopes in Precipitation over South America: Comparing Regional to Global Circulation Models  

E-Print Network [OSTI]

an isotopic signature similar to Rayleigh distillation, in accordance with experimental studies. Finally, in order to relate the simulation analysis to the fractionation mechanisms. This confirms that the amount effect, via Rayleigh distillation processes, is dominant during the wet season. During the dry season

Sturm, Christophe "Kristof"

458

Strontium isotope evidence of Neanderthal mobility at the site of Lakonis, Greece using laser-ablation PIMMS  

E-Print Network [OSTI]

Strontium isotope evidence of Neanderthal mobility at the site of Lakonis, Greece using laser the measurement of strontium isotope ratios in tooth enamel using laser- ablation, which allows us to use much in a coastal limestone cave, yet the strontium isotope values indicate the enamel was formed while

Smith, Tanya M.

459

Strontium and carbon isotope stratigraphy of the Late Jurassic shallow marine limestone in western Palaeo-Pacific, northwest Borneo  

E-Print Network [OSTI]

Strontium and carbon isotope stratigraphy of the Late Jurassic shallow marine limestone in western-Pacific a b s t r a c t Strontium and carbon isotope stratigraphy was applied to a 202 m-thick shallow marine, which was deposited in the western Palaeo-Pacific. Strontium isotopic ratios of rudist specimens suggest

Gilli, Adrian

460

Effect of atmospheric water vapor on modification of stable isotopes in near-surface snow on ice sheets  

E-Print Network [OSTI]

temperature and the abundance of heavy isotopes of water found in water vapor and precipitation as functionsEffect of atmospheric water vapor on modification of stable isotopes in near-surface snow on ice fractionation model is developed to investigate postdepositional modification of stable isotopes of water

Walden, Von P.

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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.


461

An extended organic carbon-isotope record across the TriassicJurassic boundary in the Queen Charlotte Islands,  

E-Print Network [OSTI]

a negative offset in baseline carbon isotope values from approximately -29 in the Late Norian to -31An extended organic carbon-isotope record across the Triassic­Jurassic boundary in the Queen carbon-isotope data are presented for the Triassic­Jurassic boundary section at Kennecott Point, Queen

Williford, Kenneth H.

462

Physics of Aquatic Systems II, 3. Stable Isotopes -Theory Universitt HeidelbergInstitut fr Umweltphysik Physics of Aquatic Systems II  

E-Print Network [OSTI]

­ Notation and definitions ­ Origin and description of fractionation ­ Fractionating processes ­ Rayleigh distillation Literature: Mook Vol. I, ch. 3 and 4 Physics of Aquatic Systems II, 3. Stable Isotopes - Theory "concentration" or mixing ratio: Fractional abundance of given isotope relative to all isotopes of the element

Aeschbach-Hertig, Werner

463

OXYGEN ISOTOPE MEASUREMENTS OF A RARE MURCHISON TYPE A CAI AND ITS RIM. J. E. P. , J. I. Simon2  

E-Print Network [OSTI]

OXYGEN ISOTOPE MEASUREMENTS OF A RARE MURCHISON TYPE A CAI AND ITS RIM. J. E. P. Matzel1 , J. I-rich inclusions (CAIs) from CV chondrites commonly show oxygen isotope hetero- geneity among different mineral large and systematic variations in oxygen isotope composition within the margin and Wark-Lovering rim

Grossman, Lawrence

464

Isotope shift in the electron affinity of lithium  

SciTech Connect (OSTI)

Very accurate electron affinity (EA) calculations of {sup 6}Li and {sup 7}Li (and {sup {infinity}L}i) have been performed using explicitly correlated Gaussian functions and a variational approach that explicitly includes the nuclear motion in the calculations (i.e., the approach that does not assume the Born-Oppenheimer approximation). The leading relativistic and quantum electrodynamics corrections to the electron affinities were also calculated. The results are the most accurate theoretical values obtained for the studied systems to date. Our best estimates of the {sup 7}Li and {sup 6}Li EAs are 4984.9842(30) and 4984.9015(30) cm{sup -1}, respectively, and of the {sup 7}Li/{sup 6}Li EA isotope shift is 0.0827 cm{sup -1}.

Bubin, Sergiy [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States); Komasa, Jacek [Quantum Chemistry Group, Faculty of Chemistry, A. Mickiewicz University, ulica Grunwaldzka 6, 60-780 Poznan (Poland); Stanke, Monika [Institute of Physics, Nicholas Copernicus University, ulica Grudziadzka 5, PL 87-100 Torun (Poland); Adamowicz, Ludwik [Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721 (United States); Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)

2009-12-21T23:59:59.000Z

465

Green's functions and hydrodynamics for isotopic binary diffusion  

E-Print Network [OSTI]

We study classical binary fluid mixtures in which densities vary on very short time (ps) and length (nm) scales, such that hydrodynamics does not apply. In a pure fluid with a localized heat pulse the breakdown of hydrodynamics was overcome using Green's functions which connect the initial densities to those at later times. Numerically it appeared that for long times the results from the Green's functions would approach hydrodynamics. In this paper we extend the Green's functions theory to binary mixtures. For the case of isothermal isobaric mutual diffusion in isotopic binary mixtures and ideal binary mixtures, which is easier to handle than heat conduction yet still non-trivial, we show analytically that in the Green's function approach one recovers hydrodynamic behaviour at long time scales provided the system reaches local equilibrium at long times. This is a first step toward giving the Green's function theory a firmer basis because it can for this case be considered as an extension of hydrodynamics.

R. van Zon; E. G. D. Cohen

2005-08-10T23:59:59.000Z

466

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

SciTech Connect (OSTI)

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

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

2012-01-01T23:59:59.000Z

467

A monopole-optimized effective interaction for tin isotopes  

E-Print Network [OSTI]

We present a systematic configuration-interaction shell model calculation on the structure of light tin isotopes with a new global optimized effective interaction. The starting point of the calculation is the realistic CD-Bonn nucleon-nucleon potential. The unknown single-particle energies of the $1d_{3/2}$, $2s_{1/2}$ and $0h_{11/2}$ orbitals and the T=1 monopole interactions are determined by fitting to the binding energies of 157 low-lying yrast states in $^{102-132}$Sn. We apply the Hamiltonian to analyze the origin of the spin inversion between $^{101}$Sn and $^{103}$Sn that was observed recently and to explore the possible contribution from interaction terms beyond the normal pairing.

Chong Qi; Z. X. Xu

2012-10-09T23:59:59.000Z

468

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

469

Selective Rotational Excitation of Molecular Isotopes and Nuclear Spin Isomers  

E-Print Network [OSTI]

Following excitation by a strong ultra-short laser pulse, molecules develop coordinated rotational motion, exhibiting transient alignment along the direction of the laser electric field, followed by periodic full and fractional revivals that depend on the molecular rotational constants. In mixtures, the different species undergo similar rotational dynamics, all starting together but evolving differently with each demonstrating its own periodic revival cycles. For a bimolecular mixture of linear molecules, at predetermined times, one species may attain a maximally aligned state while the other is anti-aligned (i.e. molecular axes are confined in a plane perpendicular to the laser electric field direction). By a properly timed second laser pulse, the rotational excitation of the undesired species may be almost completely removed leaving only the desired species to rotate and periodically realign, thus facilitating further selective manipulations by polarized light. In this paper, such double excitation schemes are demonstrated for mixtures of molecular isotopes (isotopologues) and for nuclear spin isomers.

Sharly Fleischer; Ilya. Sh. Averbukh; Yehiam Prior

2007-02-15T23:59:59.000Z

470

Low temperature carrier transport properties in isotopically controlled germanium  

SciTech Connect (OSTI)

Investigations of electronic and optical properties of semiconductors often require specimens with extremely homogeneous dopant distributions and precisely controlled net-carrier concentrations and compensation ratios. The previous difficulties in fabricating such samples are overcome as reported in this thesis by growing high-purity Ge single crystals of controlled {sup 75}Ge and {sup 70}Ge isotopic compositions, and doping these crystals by the neutron transmutation doping (NTD) technique. The resulting net-impurity concentrations and the compensation ratios are precisely determined by the thermal neutron fluence and the [{sup 74}Ge]/[{sup 70}Ge] ratios of the starting Ge materials, respectively. This method also guarantees unprecedented doping uniformity. Using such samples the authors have conducted four types of electron (hole) transport studies probing the nature of (1) free carrier scattering by neutral impurities, (2) free carrier scattering by ionized impurities, (3) low temperature hopping conduction, and (4) free carrier transport in samples close to the metal-insulator transition.

Itoh, K.

1994-12-01T23:59:59.000Z

471

Methods for separating medical isotopes using ionic liquids  

SciTech Connect (OSTI)

A method for extracting a radioisotope from an aqueous solution, the method comprising: a) intimately mixing a non-chelating ionic liquid with the aqueous solution to transfer at least a portion of said radioisotope to said non-chelating ionic liquid; and b) separating the non-chelating ionic liquid from the aqueous solution. In preferred embodiments, the method achieves an extraction efficiency of at least 80%, or a separation factor of at least 1.times.10.sup.4 when more than one radioisotope is included in the aqueous solution. In particular embodiments, the method is applied to the separation of medical isotopes pairs, such as Th from Ac (Th-229/Ac-225, Ac-227/Th-227), or Ra from Ac (Ac-225 and Ra-225, Ac-227 and Ra-223), or Ra from Th (Th-227 and Ra-223, Th-229 and Ra-225).

Luo, Huimin; Boll, Rose Ann; Bell, Jason Richard; Dai, Sheng

2014-10-21T23:59:59.000Z

472

Isotopic generator for bismuth-212 and lead-212 from radium  

DOE Patents [OSTI]

A method and apparatus for providing radionuclides of bismuth-212 and lead-212. Thorium-228 and carrier solution starting material is input to a radiologically contained portion of an isotopic generator system, and radium-224 is separated from thorium-228 which is retained by a strongly basic anion exchange column. The separated radium-224 is transferred to an accessible, strongly acidic cationic exchange column. The cationic column retains the radium-224, and natural radioactive decay generates bismuth-212 and lead-212. The cationic exchange column can also be separated from the contained portion of the system and utilized without the extraordinary safety measures necessary in the contained portion. Furthermore, the cationic exchange column provides over a relatively long time period the short lived lead-212 and bismuth-212 radionuclides which are useful for a variety of medical therapies.

Atcher, Robert W. (Kensington, MD); Friedman, Arnold M. (Park Forest, IL); Hines, John (Glen Ellyn, IL)

1987-01-01T23:59:59.000Z

473

Separated isotopes: vital tools for science and medicine  

SciTech Connect (OSTI)

Deliberations and conclusions of a Workshop on Stable Isotopes and Derived Radioisotopes organized by the Subcommittee on Nuclear and Radiochemistry of the National Research Council's Committee on Chemical Sciences at the request of the Department of Energy (DOE) are summarized. The workshop was jointly supported by the National Institutes of Health and DOE's Office of Basic Energy Sciences. An overview with three recommendations resulting from the Workshop is followed by reports of the four Workshop panels. Background papers were prepared by individuals on the Steering Committee and made available to all participants prior to the Workshop. They are reproduced as Appendixes 3 to 8. Short reports on alternate separation techniques were presented at the Workshop and are reproduced in Appendixes 9 to 11.

Not Available

1982-01-01T23:59:59.000Z

474

Isotopic tracers of gold deposition in Paleozoic limestones, Southern Nevada  

SciTech Connect (OSTI)

Strontium isotopic analyses of barren and mineralized Paleozoic carbonate rocks show that hydrothermal fluids added radiogenic strontium ({sup 87}Sr) to the mineralized zones. At Bare Mountain, samples collected from mineralized areas have {delta}{sup 87}Sr{sub t} values ranging from +3.0 to +23.0, whereas unmineralized carbonate rocks have {delta}{sup 87}Sr, values of {minus}0.6 to +2.9. In other ranges, {delta}{sup 87}Sr, values of the unmineralized carbonate rocks are even lower and virtually indistinguishable from primary marine values. This correlation of elevated {delta}{sup 87}Sr{sub t} values with mineralized zones provides a useful technique for assessing the mineral potential of the Paleozoic basement beneath Yucca Mountain, and may find broader use in mineral exploration in the Basin and Range province as a whole.

Peterman, Z.E.; Widmann, B.L.; Marshall, B.D.; Aleinikoff, J.N.; Futa, K.; Mahan, S.A.

1994-12-31T23:59:59.000Z

475

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

476

Gamma Spectrum from Neutron Capture on Tungsten Isotopes  

SciTech Connect (OSTI)

An evaluation of thermal neutron capture on the stable tungsten isotopes is presented, with preliminary results for the compound systems 183;184;185;187W. The evaluation procedure compares the g-ray cross-section data collected at the Budapest reactor, with Monte Carlo simulations of g-ray emission following the thermal neutron-capture process. The statistical-decay code DICEBOX was used for the Monte Carlo simulations. The evaluation yields new gamma rays in 185W and the confirmation of spins in 187W, raising the number of levels below which the level schemes are considered complete, thus increasing the number of levels that can be used in neutron data libraries.

Hurst, Aaron; Summers, Neil; Sleaford, Brad; Firestone, Richard B; Belgya, T.; Revay, Z.S.

2010-04-29T23:59:59.000Z

477

Modeling of temporal behavior of isotopic exchange between gaseous hydrogen and palladium hydride power  

SciTech Connect (OSTI)

A parametric rate-equation model is described which depicts the time dependent behavior of the isotopic exchange process occurring between the solid and gas phases in gaseous hydrogen (deuterium) flows through packed-powder palladium deuteride (hydride) beds. The exchange mechanism is assumed to be rate-limited by processes taking place on the surface of the powder. The fundamental kinetic parameter of the model is the isotopic exchange probability, p, which is the probability that an isotopic exchange event occurs during a collision of a gas phase atom with the surface. Isotope effects between the gas and solid phases are explicitly included in terms of the isotope separation factor, ..cap alpha... Results of the model are compared with recent experimental measurements of isotope exchange in the ..beta..-phase hydrogen/palladium system and, using a literature value of ..cap alpha.. = 2.4, a good description of the experimental data is obtained for p approx. 10/sup -7/. In view of the importance of the isotope effects in the hydrogen/palladium system and the range of ..cap alpha.. values reported for the ..beta..-phase in the literature, the sensitivity of the model results to a variation in the value of ..cap alpha.. is examined.

Melius, C F; Foltz, G W

1987-01-01T23:59:59.000Z

478

National uses and needs for separated stable isotopes in physics, chemistry, and geoscience research  

SciTech Connect (OSTI)

Present uses of separated stable isotopes in the fields of physics, chemistry, and the geosciences have been surveyed to identify current supply problems and to determine future needs. Demand for separated isotopes remains strong, with 220 different nuclides having been used in the past three years. The largest needs, in terms of both quantity and variety of isotopes, are found in nuclear physics research. Current problems include a lack of availability of many nuclides, unsatisfactory enrichment of rare species, and prohibitively high costs for certain important isotopes. It is expected that demands for separated isotopes will remain roughly at present levels, although there will be a shift toward more requests for highly enriched rare isotopes. Significantly greater use will be made of neutron-rich nuclides below A = 100 for producing exotic ion beams at various accelerators. Use of transition metal nuclei for nuclear magnetic resonance spectroscopy will expand. In addition, calibration standards will be required for the newer techniques of radiological dating, such as the Sm/Nd and Lu/Hf methods, but in relatively small quantities. Most members of the research community would be willing to pay considerably more than they do now to maintain adequate supplies of stable isotopes.

Zisman, M.S.

1982-01-01T23:59:59.000Z

479

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

SciTech Connect (OSTI)

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

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

2011-01-15T23:59:59.000Z

480

Innovative lasers for uranium isotope separation. [Progress report  

SciTech Connect (OSTI)

Copper vapor lasers have important applications to uranium atomic vapor laser isotope separation (AVLIS). The authors have spent the first two years of their project investigating two innovative methods of exciting/pumping copper vapor lasers which have the potential to improve the efficiency and scaling of large laser systems used in uranium isotope separation. Experimental research has focused on the laser discharge kinetics of (1) microwave, and (2) electron beam excitation/pumping of large-volume copper vapor lasers. During the first year, the experiments have been designed and constructed and initial data has been taken. During the second year these experiments have been diagnosed. Highlights of some of the second year results as well as plans for the future include the following: Microwave resonant cavity produced copper vapor plasmas at 2.45 GHz, have been investigated. A CW (0--500 W) signal heats and vaporizes the copper chloride to provide the atomic copper vapor. A pulsed (5 kW, 0.5--5kHz) signal is added to the incoming CW signal via a hybrid mixer to excite the copper states to the laser levels. An enhancement of the visible radiation has been observed during the pulsed pardon of the signal. Electrical probe measurements have been implemented on the system to verify the results of the electromagnetic model formulated last year. Laser gain measurements have been initiated with the use of a commercial copper vapor laser. Measurements of the spatial profile of the emission are also currently being made. The authors plan to increase the amount of pulsed microwave power to the system by implementing a high power magnetron. A laser cavity will be designed and added to this system.

Brake, M.L.; Gilgenbach, R.M.

1991-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "isotopic analysis isotopic" 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.


481

Consistent Data Assimilation of Isotopes: 242Pu and 105Pd  

SciTech Connect (OSTI)

In this annual report we illustrate the methodology of the consistent data assimilation that allows to use the information coming from integral experiments for improving the basic nuclear parameters used in cross section evaluation. A series of integral experiments are analyzed using the EMPIRE evaluated files for 242Pu and 105Pd. In particular irradiation experiments (PROFIL-1 and -2, TRAPU-1, -2 and -3) provide information about capture cross sections, and a critical configuration, COSMO, where fission spectral indexes were measured, provides information about fission cross section. The observed discrepancies between calculated and experimental results are used in conjunction with the computed sensitivity coefficients and covariance matrix for nuclear parameters in a consistent data assimilation. The results obtained by the consistent data assimilation indicate that not so large modifications on some key identified nuclear parameters allow to obtain reasonable C/E. However, for some parameters such variations are outside the range of 1 s of their initial standard deviation. This can indicate a possible conflict between differential measurements (used to calculate the initial standard deviations) and the integral measurements used in the statistical data adjustment. Moreover, an inconsistency between the C/E of two sets of irradiation experiments (PROFIL and TRAPU) is observed for 242Pu. This is the end of this project funded by the Nuclear Physics Program of the DOE Office of Science. We can indicate that a proof of principle has been demonstrated for a few isotopes for this innovative methodology. However, we are still far from having explored all the possibilities and made this methodology to be considered proved and robust. In particular many issues are worth further investigation: • Non-linear effects • Flexibility of nuclear parameters in describing cross sections • Multi-isotope consistent assimilation • Consistency between differential and integral experiments

G. Palmiotti; H. Hiruta; M. Salvatores

2012-09-01T23:59:59.000Z

482

Low-energy electric dipole response of Sn isotopes  

E-Print Network [OSTI]

We study the low-energy dipole (LED) strength distribution along the Sn isotopic chain in both the isoscalar (IS) and the isovector (IV, or E1) electric channels, to provide testable predictions and guidance for new experiments with stable targets and radioactive beams. We use the self-consistent Quasi-particle Random-Phase Approximation (QRPA) with finite-range interactions and mainly the Gogny D1S force. We analyze also the performance of a realistic two-body interaction supplemented by a phenomenological three-body contact term. We find that from N=50 and up to the N=82 shell closure (132Sn) the lowest-energy part of the IS-LED spectrum is dominated by a collective transition whose properties vary smoothly with neutron number and which cannot be interpreted as a neutron-skin oscillation. For the neutron-rich species this state contributes to the E1 strength below particle threshold, but much more E1 strength is carried by other, weak but numerous transitions around or above threshold. We find that strong structural changes in the spectrum take effect beyond N=82, namely increased LED strength and lower excitation energies. Our results with the Gogny interaction are compatible with existing data. On this basis we predict that a) the summed IS strength below particle threshold shall be of the same order of magnitude for N=50-82, b) the summed E1 strength up to approximately 12 MeV shall be similar for N=50-82 MeV, while c) the summed E1 strength below threshold shall be of the same order of magnitude for N ~ 64 - 82 and much weaker for the lighter, more-symmetric isotopes. We point out a general agreement of our results with other non-relativistic studies, the absence of a collective IS mode in some of those studies, and a possibly radical disagreement with relativistic models.

P. Papakonstantinou; H. Hergert; V. Yu. Ponomarev; R. Roth

2014-03-10T23:59:59.000Z

483

Successful application of lead isotopes in source apportionment, legal proceedings, remediation and monitoring  

SciTech Connect (OSTI)

In late 2006, the seaside community in Esperance Western Australia was alerted to thousands of native bird species dying. The source of the lead (Pb) was determined by Pb isotopes to derive from the handling of Pb carbonate concentrate through the Port, which began in July 2005. Concern was expressed for the impact of this on the community. Our objectives were to employ Pb isotope ratios to evaluate the source of Pb in environmental samples for use in legal proceedings, and for use in remediation and monitoring. Isotope measurements were undertaken of bird livers, plants, drinking water, soil, harbour sediments, air, bulk ceiling dust, gutter sludge, surface swabs and blood. The unique lead isotopic signature of the contaminating Pb carbonate enabled diagnostic apportionment of lead in samples. Apart from some soil and water samples, the proportion of contaminating Pb was >95% in the environmental samples. Lead isotopes were critical in resolving legal proceedings, are being used in the remediation of premises, were used in monitoring of workers involved in the decontamination of the storage facility, and monitoring transport of the concentrate through another port facility. Air samples show the continued presence of contaminant Pb, more than one year after shipping of concentrate ceased, probably arising from dust resuspension. Brief details of the comprehensive testing and cleanup of the Esperance community are provided along with the role of the Community. Lead isotopic analyses can provide significant benefits to regulatory agencies, interested parties, and the community where the signature is able to be characterised with a high degree of certainty. - Highlights: Black-Right-Pointing-Triangle Lead carbonate concentrate. Black-Right-Pointing-Triangle Successful use of Pb isotopes in identifying sources of Pb arising from transport and shipping. Black-Right-Pointing-Triangle Use of Pb isotopes in legal proceedings and their use in cleanup of residences. Black-Right-Pointing-Triangle Use of Pb isotopes in cleanup of a residual 9000 tonnes of Pb carbonate and in ongoing monitoring.

Gulson, Brian, E-mail: brian.gulson@mq.edu.au [Graduate School of the Environment, Faculty of Science, Macquarie University, Sydney, NSW 2109 (Australia) [Graduate School of the Environment, Faculty of Science, Macquarie University, Sydney, NSW 2109 (Australia); CSIRO Earth Science and Resource Engineering North Ryde, NSW 1670 (Australia); Korsch, Michael [CSIRO Earth Science and Resource Engineering North Ryde, NSW 1670 (Australia)] [CSIRO Earth Science and Resource Engineering North Ryde, NSW 1670 (Australia); Winchester, Wayne; Devenish, Matthew; Hobbs, Thad [Esperance Cleanup and Recovery Project, Western Australia (WA) Department of Transport, Esperance 6450 (Australia)] [Esperance Cleanup and Recovery Project, Western Australia (WA) Department of Transport, Esperance 6450 (Australia); Main, Cleve; Smith, Gerard [Animal Health Laboratory, Department of Agriculture and Food, Perth 6151, WA (Australia)] [Animal Health Laboratory, Department of Agriculture and Food, Perth 6151, WA (Australia); Rosman, Kevin; Howearth, Lynette; Burn-Nunes, Laurie [Curtin University, Department of Imaging and Applied Physics, Bentley 6102, WA (Australia)] [Curtin University, Department of Imaging and Applied Physics, Bentley 6102, WA (Australia); Seow, Jimmy; Oxford, Cameron [Department of Environment and Conservation, Booragoon 6154, WA (Australia)] [Department of Environment and Conservation, Booragoon 6154, WA (Australia); Yun, Gracie; Gillam, Lindsay [Department of Health, East Perth 6004, WA (Australia)] [Department of Health, East Perth 6004, WA (Australia); Crisp, Michelle [LED (Locals for Esperance Development), Esperance 6450, WA (Australia)] [LED (Locals for Esperance Development), Esperance 6450, WA (Australia)

2012-01-15T23:59:59.000Z

484

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

E-Print Network [OSTI]

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

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

2009-01-16T23:59:59.000Z

485

Constraining the symmetry energy from the neutron skin thickness of Tin isotopes  

E-Print Network [OSTI]

We show in the Skyrme-Hartree-Fock approach that unambiguous correlations exist between observables of finite nuclei and nuclear matter properties. Using this correlation analysis to existing data on the neutron skin thickness of Sn isotopes, we find important constraints on the value E_{sym}(rho_0) and density slope L of the nuclear symmetry energy at saturation density. Combining these constraints with those from recent analyses of isospin diffusion and double neutron/proton ratio in heavy ion collisions leads to a value of L=58\\pm 18 MeV approximately independent of E_{sym}(\\rho_0).

Lie-Wen Chen; Che Ming Ko; Jun Xu; Bao-An Li

2011-03-24T23:59:59.000Z

486

High-spin structures of $^{77,79,81,83}$As isotopes  

E-Print Network [OSTI]

In the present work we report comprehensive set of shell model calculations for arsenic isotopes. We performed shell model calculations with two recent effective interactions JUN45 and jj44b. The overall results for the energy levels and magnetic moments are in rather good agreement with the available experimental data. We have also reported competition of proton- and neutron-pair breakings analysis to identify which nucleon pairs are broken to obtain the total angular momentum of the calculated states. Further theoretical development is needed by enlarging model space by including $\\pi 0f_{7/2}$ and $\

Kumar, Vikas; Morales, Irving O

2015-01-01T23:59:59.000Z

487

The use of isotopically tailored boron for advanced neutron shielding and moderating applications  

E-Print Network [OSTI]

cm. The incident neutron flux was measured first without any shielding slab between the source and the detector. The first slab of shielding material was then placed nearest to the source and the transmitted intensity was measured by the detector... effects of nuclear radiation. This analysis examined the use of isotopically tailored boron for the purpose of moderating, reflecting and shielding neutrons. The source of neutrons in this study varied in energy from 0. 2 keV to 14 MeV. The material...

Deere, Laura Marie

2012-06-07T23:59:59.000Z

488

Literature review of United States utilities computer codes for calculating actinide isotope content in irradiated fuel  

SciTech Connect (OSTI)

This paper reviews the accuracy and precision of methods used by United States electric utilities to determine the actinide isotopic and element content of irradiated fuel. After an extensive literature search, three key code suites were selected for review. Two suites of computer codes, CASMO and ARMP, are used for reactor physics calculations; the ORIGEN code is used for spent fuel calculations. They are also the most widely used codes in the nuclear industry throughout the world. Although none of these codes calculate actinide isotopics as their primary variables intended for safeguards applications, accurate calculation of actinide isotopic content is necessary to fulfill their function.

Horak, W.C.; Lu, Ming-Shih

1991-12-01T23:59:59.000Z

489

Full $fp$-shell study of even-even $^{48-56}$Ti isotopes  

E-Print Network [OSTI]

The level schemes and transition rates {\\em B}({\\em E}2;$\\uparrow$) of eve-even $^{48-56}$Ti isotopes were studied by performing large-scale shell model calculations with FPD6 and GXPF1 effective interactions. Excellent agreement were obtained by comparing the first 2$^{+}$ level for all isotopes with the recently available experimental data, but studying the transition strengths {\\em B}({\\em E}2; 0$^+_{g.s.} \\to2^+_1$) for all Ti isotopes using constant proton-neutron effective charges prove the limitations of the present large-scale calculations to reproduce the experiment in detail.

F. A. Majeed; A. A. Auda

2006-02-02T23:59:59.000Z

490

Oxygen isotope anomalies of the Sun and the original environment of the Solar system  

E-Print Network [OSTI]

We present results from a model of oxygen isotopic anomaly production through selective photodissociation of CO within the collapsing proto-Solar cloud. Our model produces a proto-Sun with a wide range of Delta_17O values depending on the intensity of the ultraviolet radiation field. Dramatically different results from two recent Solar wind oxygen isotope measurements indicate that a variety of compositions remain possible for the solar oxygen isotope composition. However, constrained by other measurements from comets and meteorites, our models imply the birth of the Sun in a stellar cluster with an enhanced radiation field and are therefore consistent with a supernova source for 60Fe in meteorites.

Jeong-Eun Lee; Edwin A. Bergin; James R. Lyons

2008-03-05T23:59:59.000Z

491

Isotope and Nuclear Chemistry Division annual report FY 1986, October 1985-September 1986  

SciTech Connect (OSTI)

This report describes progress in the major research and development programs carried out in FY 1986 by the Isotope and Nuclear Chemistry Division. The report includes articles on radiochemical diagnostics and weapons tests; weapons radiochemical diagnostics research and development; other unclassified weapons research; stable and radioactive isotope production and separation; chemical biology and nuclear medicine; element and isotope transport and fixation; actinide and transition metal chemistry; structural chemistry, spectroscopy, and applications; nuclear structure and reactions; irradiation facilities; advanced concepts and technology; and atmospheric chemistry.

Heiken, J.H. (ed.)

1987-06-01T23:59:59.000Z

492

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/SurfacePump-Testing Sign InIsotopeIsotope andIsotope

493

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/SurfacePump-Testing Sign InIsotopeIsotopeIsotope and

494

Isotope and Temperature Effects in Liquid Water Probed by Soft X Rays  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFunInfrared LandResponsesIon/SurfacePump-Testing Sign InIsotopeIsotopeIsotope

495

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

SciTech Connect (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

496

Pb Isotopes as an Indicator of the Asian Contribution to Particulate Air Pollution in Urban California  

SciTech Connect (OSTI)

During the last two decades, expanding industrial activity in east Asia has led to increased production of airborne pollutants that can be transported to North America. Previous efforts to detect this trans-Pacific pollution have relied upon remote sensing and remote sample locations. We tested whether Pb isotope ratios in airborne particles can be used to directly evaluate the Asian contribution to airborne particles of anthropogenic origin in western North America, using a time series of samples from a pair of sites upwind and downwind of the San Francisco Bay Area. Our results for airborne Pb at these sites indicate a median value of 29 Asian origin, based on mixing relations between distinct regional sample groups. This trans-Pacific Pb is present in small quantities but serves as a tracer for airborne particles within the growing Asian industrial plume. We then applied this analysis to archived samples from urban sites in central California. Taken together, our results suggest that the analysis of Pb isotopes can reveal the distribution of airborne particles affected by Asian industrial pollution at urban sites in northern California. Under suitable circumstances, this analysis can improve understanding of the global transport of pollution, independent of transport models.

Ewing, Stephanie A.; Christensen, John N.; Brown, Shaun T.; Vancuren, Richard A.; Cliff, Steven S.; DePaolo, Donald J.

2010-10-25T23:59:59.000Z

497

A stable isotope stratigraphy for the Axel Heiberg Fossil Forest and its application to Eocene climate  

E-Print Network [OSTI]

The Eocene era was a warm, climatically dynamic transitional period between the Paleocene greenhouse world and the Oligocene icehouse world. This study details carbon and hydrogen isotopic and biomarker analyses of samples ...

Byrne, Monica C. (Monica Catherine)

2005-01-01T23:59:59.000Z

498

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

E-Print Network [OSTI]

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

McLean, Noah Morgan

499

Clumped Isotope Thermometry in Deeply Buried Sedimentary Carbonates: The Effects of Bond Reordering Kinetics and Recrystallization  

E-Print Network [OSTI]

completely equilibrated at maximum burial temperatures, and reflect blocking temperatures achieved during cooling. Relative to the brachiopod calcite, the 40-50 °C cooler clumped isotope temperatures measured in Bird Spring Formation crinoids and host rock...

Shenton, Brock Jay

2014-08-06T23:59:59.000Z

500

LITHIUM ISOTOPIC COMPOSITION OF CHONDRITIC METEORITES. W. F. McDonough1 , P. B. Tomascak1  

E-Print Network [OSTI]

LITHIUM ISOTOPIC COMPOSITION OF CHONDRITIC METEORITES. W. F. McDonough1 , F- Z. Teng1 , P. B processes involving aqueous fluids, given the potential solubility of lithium [1]. In this respect, Li

Mcdonough, William F.