Powered by Deep Web Technologies
Note: This page contains sample records for the topic "helium isotope perspective" 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

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

Open Energy Info (EERE)

Helium Isotope Perspective On The Dixie Valley, Nevada, Hydrothermal System Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Helium Isotope...

2

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

Open Energy Info (EERE)

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

3

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

Open Energy Info (EERE)

Mantle Helium And Carbon Isotopes In Separation Creek Geothermal Springs, Three Sisters Area, Central Oregon- Evidence For Renewed Volcanic Activity Or A Long Term Steady State...

4

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

Open Energy Info (EERE)

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

5

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

6

Mantle Helium And Carbon Isotopes In Separation Creek Geothermal Springs,  

Open Energy Info (EERE)

Mantle Helium And Carbon Isotopes In Separation Creek Geothermal Springs, Mantle Helium And Carbon Isotopes In Separation Creek Geothermal Springs, Three Sisters Area, Central Oregon- Evidence For Renewed Volcanic Activity Or A Long Term Steady State System(Question) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Mantle Helium And Carbon Isotopes In Separation Creek Geothermal Springs, Three Sisters Area, Central Oregon- Evidence For Renewed Volcanic Activity Or A Long Term Steady State System(Question) Details Activities (1) Areas (1) Regions (0) Abstract: Here 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 central Oregon. The Separation Creek area which is several miles due west of the volcano is the locus of

7

Isotope Effects and Helium Retention Behavior in Vanadium Tritide  

SciTech Connect

The relaxation times of the H, T, and 3He nuclei have been measured in vanadium hydride and tritide samples. Substantial isotope effects in both the phase transition temperatures and diffusion parameters have been found. When compared to hydrides, the tritide samples have lower transition temperatures and faster mobilities. The differences in the occupancies of the interstitial sites are largely responsible for these isotope effects. Most of the helium atoms generated by tritium decay remain trapped in microscopic bubbles formed with the VTx lattice. Evidence is presented for the gradual growth of the helium bubbles over periods of hundreds of days.

Bowman, Jr., R. C.; Attalla, A., and Craft, B. D.

1985-04-01T23:59:59.000Z

8

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

9

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

Open Energy Info (EERE)

And Local Trends In Helium Isotopes, Basin And Range Province, And Local Trends In Helium Isotopes, Basin And Range Province, Western North America- Evidence For Deep Permeable Pathways Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Regional And Local Trends In Helium Isotopes, Basin And Range Province, Western North America- Evidence For Deep Permeable Pathways Details Activities (1) Areas (1) Regions (0) Abstract: Fluids from the western margin of the Basin and Range have helium isotope ratios as high as ~6-7 Ra, indicating a strong mantle melt influence and consistent with recent and current volcanic activity. Moving away from these areas, helium isotope ratios decrease rapidly to 'background' values of around 0.6 Ra, and then gradually decrease toward the east to low values of ~0.1 Ra at the eastern margin of the Basin and

10

Helium isotopes in geothermal systems- Iceland, The Geysers, Raft River and  

Open Energy Info (EERE)

Helium isotopes in geothermal systems- Iceland, The Geysers, Raft River and Helium isotopes in geothermal systems- Iceland, The Geysers, Raft River and Steamboat Springs Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Helium isotopes in geothermal systems- Iceland, The Geysers, Raft River and Steamboat Springs Details Activities (3) Areas (3) Regions (0) Abstract: Helium isotope ratios have been measured in geothermal fluids from Iceland, The Geysers, Raft River, Steamboat Springs and Hawaii. These ratios have been interpreted in terms of the processes which supply He in distinct isotopic ratios (i.e. magmatic He, ~10 Ra; atmospheric He, R,sub>a; and crustal He, ~0.1 Ra) and in terms of the processes which can alter the isotopic ratio (hydrologic mixing, U-Th series alpha production and weathering release of crustal He, magma aging and

11

Helium Isotopes In Geothermal And Volcanic Gases Of The Western United  

Open Energy Info (EERE)

Helium Isotopes In Geothermal And Volcanic Gases Of The Western United Helium Isotopes In Geothermal And Volcanic Gases Of The Western United States, I, Regional Variability And Magmatic Origin Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Helium Isotopes In Geothermal And Volcanic Gases Of The Western United States, I, Regional Variability And Magmatic Origin Details Activities (1) Areas (1) Regions (0) Abstract: Helium isotope ratios in gases of thirty hot springs and geothermal wells and of five natural gas wells in the western United States show no relationship to regional conductive heat flow, but do show a correlation with magma-based thermal activity and reservoir fluid temperature (or total convective heat discharge). Gases from high-T (> 200°C) reservoirs have 3He/4He > 2 _ the atmospheric value, with high He

12

Flow of mantle fluids through the ductile lower crust: Helium isotope trends  

E-Print Network (OSTI)

super-imposed on regional trends can identify potentialCrust: Helium Isotope Trends I B. Mack Kennedyl andlMatthijsin the west, a regional trend that correlates with the rates

Kennedy, B. Mack; van Soest, Matthijs C.

2008-01-01T23:59:59.000Z

13

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

Open Energy Info (EERE)

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

14

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

DOE Green Energy (OSTI)

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

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

1976-10-20T23:59:59.000Z

15

Isotopic Anomalies in CP Stars: Helium, Mercury, Platinum, and Calcium  

E-Print Network (OSTI)

We review the classical observational results for isotopic abundance variations for several elements in CP stars. We concentrate on the "newest" anomaly, in calcium. The cosmically very rare isotope, Ca-48 can rival and even dominate the more common, alpha nuclide, Ca-40. Relevant examples are found in the hot, non-magnetic HgMn stars, and the field horizontal-branch star, Feige 86. The calcium anomaly is also present in cool, magnetic stars, including the notorious HD 101065, Przybylski's star.

C. R. Cowley; S. Hubrig; F. Castelli

2007-11-15T23:59:59.000Z

16

A Systematic Regional Trend in Helium Isotopes Across the Northern Basin and Range Province, Western North America  

E-Print Network (OSTI)

Temperatures in the Dixie Valley, Nevada, geothermal system.and rocks from the Dixie Valley region, Nevada (1996-1999),isotope perspective on the Dixie Valley, Nevada hydrothermal

Kennedy, B. Mack; van Soest, Matthijs C.

2005-01-01T23:59:59.000Z

17

A systematic regional trend in helium isotopes across the northern basin and range province, Western North America  

E-Print Network (OSTI)

Temperatures in the Dixie Valley, Nevada, geothermal system.and rocks from the Dixie Valley region, Nevada (1996-1999),isotope perspective on the Dixie Valley, Nevada hydrothermal

Kennedy, B. Mack; van Soest, Matthijs C.

2006-01-01T23:59:59.000Z

18

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

DOE Green Energy (OSTI)

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

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

2011-01-28T23:59:59.000Z

19

A systematic regional trend in helium isotopes across the northernbasin and range province, Western North America  

Science Conference Proceedings (OSTI)

An extensive study of helium isotopes in fluids collectedfrom surface springs, fumaroles and wells across the northern Basin andRange Province reveals a systematic trend of decreasing 3He/4He ratiosfrom west to east. The western margin of the Basin and Range ischaracterized by mantle-like ratios (6-8 Ra) associated with active orrecently active crustal magma systems (e.g., Coso, Long Valley,Steamboat, and the Cascade volcanic complex). Moving towards the east,the ratios decline systematically to a background value of ~;0.1 Ra. Theregional trend is consistent with extensive mantle melting concentratedalong the western margin and is coincident with an east-to-west increasein the magnitude of northwest strain. The increase in shear strainenhances crustal permeability resulting in high vertical fluid flow ratesthat preserve the high helium isotope ratios at the surface. Superimposedon the regional trend are "helium spikes," local anomalies in the heliumisotope composition. These "spikes" reflect either local zones of mantlemelting or locally enhanced crustal permeability. In the case of theDixie Valley hydrothermal system, it appears to be a combination ofboth.

Kennedy, B. Mack; van Soest, Matthijs C.

2006-05-01T23:59:59.000Z

20

Method and means of reducing erosion of components of plasma devices exposed to helium and hydrogen isotope radiation  

SciTech Connect

Surfaces of components of plasma devices exposed to radiation by atoms or ions of helium or isotopes of hydrogen can be protected from damage due to blistering by shielding the surfaces with a structure formed by sintering a powder of aluminum or beryllium and its oxide or by coating the surfaces with such a sintered metal powder.

Kaminsky, Manfred S. (Hinsdale, IL); Das, Santosh K. (Naperville, IL); Rossing, Thomas D. (De Kalb, IL)

1977-01-25T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

The effect of hydrogen isotopes and helium on the tensile properties of 21-6-9 stainless steel  

DOE Green Energy (OSTI)

High-energy-rate-forged (HERF) stainless steels are used as the materials of construction for pressure vessels designed for the containment of hydrogen and its isotopes. Hydrogen and helium, the decay product of tritium, are known to embrittle these materials. HERF stainless steels have a relatively good resistance to hydrogen-and-helium-induced embrittlement when compared to annealed stainless steels due to their high number density of dislocations, which act as traps for hydrogen and helium. However, the degree of embrittlement in these materials can vary considerably because of microstructure and yield strength variations introduced during the forging process. In this study the effect of hydrogen and tritium on the tensile properties of 21-6-9 stainless steel was measured as a function of HERF yield strength in the range of 660 to 930 MPa. The effect of microstructure was studied also be conducting tensile tests with HERF and annealed samples.

Morgan, M.J.; Lohmeier, D.

1990-12-31T23:59:59.000Z

22

The effect of hydrogen isotopes and helium on the tensile properties of 21-6-9 stainless steel  

DOE Green Energy (OSTI)

High-energy-rate-forged (HERF) stainless steels are used as the materials of construction for pressure vessels designed for the containment of hydrogen and its isotopes. Hydrogen and helium, the decay product of tritium, are known to embrittle these materials. HERF stainless steels have a relatively good resistance to hydrogen-and-helium-induced embrittlement when compared to annealed stainless steels due to their high number density of dislocations, which act as traps for hydrogen and helium. However, the degree of embrittlement in these materials can vary considerably because of microstructure and yield strength variations introduced during the forging process. In this study the effect of hydrogen and tritium on the tensile properties of 21-6-9 stainless steel was measured as a function of HERF yield strength in the range of 660 to 930 MPa. The effect of microstructure was studied also be conducting tensile tests with HERF and annealed samples.

Morgan, M.J.; Lohmeier, D.

1990-01-01T23:59:59.000Z

23

Regional and Local Trends in helium isotopes, basin and rangeprovince, western North America: Evidence for deep permeablepathways  

SciTech Connect

Fluids from the western margin of the Basin and Range have helium isotope ratios as high as {approx}6-7 Ra, indicating a strong mantle melt influence and consistent with recent and current volcanic activity. Moving away from these areas, helium isotope ratios decrease rapidly to ''background'' values of around 0.6 Ra, and then gradually decrease toward the east to low values of {approx}0.1 Ra at the eastern margin of the Basin and Range. Superimposed on this general regional trend are isolated features with elevated helium isotope ratios (0.8-2.1 Ra) compared to the local background. Spring geochemistry and local geology indicate that these ''He-spikes'' are not related to current or recent magmatic activity, suggesting that the spikes may reflect either localized zones deep mantle melting or deep permeable pathways (faults) with high vertical fluid flowrates. A detailed study of one of the He-spikes (Dixie Valley and the Stillwater Range Front Fault system), indicates that features with high 3He/4He ratios are confined to the range front normal faults characteristic of the extensional regime in the Basin and Range, suggesting that these faults are deep permeable pathways. However, not all range front fault systems transmit fluids with a mantle signature, implying that not all have deep permeable pathways.

Kennedy, B. Mack; van Soest, Matthijs C.

2005-07-15T23:59:59.000Z

24

A Systematic Regional Trend in Helium Isotopes Across the NorthernBasin and Range Province, Western North America  

Science Conference Proceedings (OSTI)

An extensive study of helium isotopes in fluids collectedfrom surface springs, fumaroles and wells across the northern Basin andRange Province reveals a systematic trend of decreasing 3He/4He ratiosfrom west to east. The western margin of the Basin and Range ischaracterized by mantle-like ratios (6-8 Ra) associated with active orrecently active crustal magma systems (e.g. Coso, Long Valley, Steamboat,and the Cascade volcanic complex). Moving towards the east, the ratiosdecline systematically to a background value of ~;0.1 Ra. The regionaltrend is consistent with extensive mantle melting concentrated along thewestern margin and is coincident with an east-to-west increase in themagnitude of northwest strain. The increase in shear strain enhancescrustal permeability resulting in high vertical fluid flow rates thatpreserve the high helium isotope ratios at the surface. Superimposed onthe regional trend are "helium spikes", local anomalies in the heliumisotope composition. These "spikes" reflect either local zones of mantlemelting or locally enhanced crustal permeability. In the case of theDixie Valley hydrothermal system, it appears to be a combination ofboth.

Kennedy, B. Mack; van Soest, Matthijs C.

2005-03-22T23:59:59.000Z

25

Isotopes of helium, hydrogen, and carbon as groundwater tracers in aquifers along the Colorado River  

E-Print Network (OSTI)

isotope studies in the Mojave Desert, California: implications for groundwater chronology and regional seismicity, Chemical Geology.

Haber, Samuel Ainsworth

2009-01-01T23:59:59.000Z

26

Dynamics of the reaction of the N/sup +/ ion with hydrogen isotopes and helium  

DOE Green Energy (OSTI)

Molecular beam techniques were used to study the reactive and non-reactive scattering of the nitrogen positive ion from hydrogen isotopes and helium, at energies above the stability limit for spectator stripping. Reactive scattering was observed from H/sub 2/ and HD targets. Non-reactive scattering was observed from H/sub 2/ and D/sub 2/ targets, and from He at one energy. A correlation diagram for the system is presented and compared with the available a priori calculations. Two surfaces are expected to lead to reaction. One is a /sup 3/A/sub 2/ - /sup 3/PI surface, the other, a /sup 3/B/sub 1/ - /sup 3/..sigma../sup -/ surface. Collinear approaches are expected to be most reactive on the /sup 3/B/sub 1/ - /sup 3/..sigma../sup -/ surface; noncollinear, on the /sup 3/A/sub 1/ - /sup 3/PI surface. Theoretical models are presented in which an incident hard sphere A, representing the projectile ion, strikes one of a pair of hard spheres B-C representing the B hydrogen molecule. After an impulsive A-B collision, an impulsive B-C collision may take place. The relative energy of A to B is then examined, and a reactive event is considered to have occurred if the energy is less than the dissociation energy for the A-B molecule. This model is treated both in the collinear case and in three dimensions. A graphical technique for the collinear case is summarized and applied to reaction on the /sup 3/B/sub 1/ - /sup 3/..sigma../sup -/ surface. An integral equation for the three-dimensional case is developed. A synthesis of two treatments, representing the behavior of the system on both reactive surfaces, and considering the charge-exchange channel, correctly predicts the observed product distribution. Predictions are also presented for the as yet unobserved case of reactive scattering from a D/sub 2/ target.

Ruska, W.E.W.

1976-06-28T23:59:59.000Z

27

Flow of mantle fluids through the ductile lower crust: Helium isotope trends  

E-Print Network (OSTI)

of the latter is the Dixie Valley thermal system (Figure 2),that crossed through Dixie Valley revealed a zone of lowsuggesting that the Dixie Valley helium anomaly rellects a

Kennedy, B. Mack; van Soest, Matthijs C.

2008-01-01T23:59:59.000Z

28

The influence of helium on mechanical properties of model austenitic alloys, determined using sup 59 Ni isotopic tailoring and fast reactor irradiation  

Science Conference Proceedings (OSTI)

The objective of this effort is to study the separate and synergistic effects of helium and other important variables on the evolution of microstructure and macroscopic properties during irradiation of structural metals. The alloys employed in this study were nominally Fe-15Cr-25Ni, Fe-15Cr-25Ni-0.04P and Fe-15Cr-45Ni (wt %) in both the cold worked and annealed conditions. Tensile testing and microscopy continue on specimens removed from the first, second and third discharges of the {sup 59}Ni isotopic doping experiment. The results to date indicate that helium/dpa ratios typical of fusion reactors (4 to 19 appm/dpa) do not lead to significant changes in the yield strength of model Fe-Cr-Ni alloys. Measurements of helium generated in undoped specimens from the second and third discharges show that the helium/dpa ratio increases during irradiation in FFTF due to the production of {sup 59}Ni. In specimens doped with {sup 59}Ni prior to irradiation, the helium/dpa ratio can increase, decrease or remain the same during the second irradiation interval. This behavior occurs because the cross sections for the production and burnout of {sup 59}Ni are very sensitive to core location and the nature of neighboring components. 14 refs., 5 figs., 3 tabs.

Hamilton, M.L.; Garner, F.A. (Pacific Northwest Lab., Richland, WA (USA)); Oliver, B.M. (Rockwell International Corp., Canoga Park, CA (USA))

1990-11-01T23:59:59.000Z

29

Primordial helium recombination III: Thomson scattering, isotope shifts, and cumulative results  

E-Print Network (OSTI)

Upcoming precision measurements of the temperature anisotropy of the cosmic microwave background (CMB) at high multipoles will need to be complemented by a more complete understanding of recombination, which determines the damping of anisotropies on these scales. This is the third in a series of papers describing an accurate theory of HeI and HeII recombination. Here we describe the effect of Thomson scattering, the $^3$He isotope shift, the contribution of rare decays, collisional processes, and peculiar motion. These effects are found to be negligible: Thomson and $^3$He scattering modify the free electron fraction $x_e$ at the level of several $\\times 10^{-4}$. The uncertainty in the $2^3P^o-1^1S$ rate is significant, and for conservative estimates gives uncertainties in $x_e$ of order $10^{-3}$. We describe several convergence tests for the atomic level code and its inputs, derive an overall $C_\\ell$ error budget, and relate shifts in $x_e(z)$ to the changes in $C_\\ell$, which are at the level of 0.5% at ...

Switzer, E R; Switzer, Eric R.; Hirata, Christopher M.

2007-01-01T23:59:59.000Z

30

Primordial helium recombination III: Thomson scattering, isotope shifts, and cumulative results  

E-Print Network (OSTI)

Upcoming precision measurements of the temperature anisotropy of the cosmic microwave background (CMB) at high multipoles will need to be complemented by a more complete understanding of recombination, which determines the damping of anisotropies on these scales. This is the third in a series of papers describing an accurate theory of HeI and HeII recombination. Here we describe the effect of Thomson scattering, the $^3$He isotope shift, the contribution of rare decays, collisional processes, and peculiar motion. These effects are found to be negligible: Thomson and $^3$He scattering modify the free electron fraction $x_e$ at the level of several $\\times 10^{-4}$. The uncertainty in the $2^3P^o-1^1S$ rate is significant, and for conservative estimates gives uncertainties in $x_e$ of order $10^{-3}$. We describe several convergence tests for the atomic level code and its inputs, derive an overall $C_\\ell$ error budget, and relate shifts in $x_e(z)$ to the changes in $C_\\ell$, which are at the level of 0.5% at $\\ell =3000$. Finally, we summarize the main corrections developed thus far. The remaining uncertainty from known effects is $\\sim 0.3%$ in $x_e$.

Eric R. Switzer; Christopher M. Hirata

2007-02-06T23:59:59.000Z

31

The effects of hydrogen isotopes and helium on the tensile properties of 21-6-9 stainless steel  

DOE Green Energy (OSTI)

High-energy-rate-forged (HERF) stainless steels are used as the materials of construction for tritium and deuterium reservoirs. Hydrogen and helium, the decay product of tritium, are known to embrittle stainless steels (1--4). The resistance to hydrogen and helium induced embrittlement is relatively good for HERF stainless steels when compared to annealed stainless steels due to their high number density of dislocations, which act as traps for hydrogen and helium. However, the degree of the embrittlement in these materials can vary considerably because of microstructure and yield strength variations introduced during the forging process. In this study the effect of hydrogen and tritium on the room temperature tensile properties of 21-6-9 stainless steel was measured as a function of HERF yield strength in the range of 500 to 918 MPa. The effect of a microstructures was studied also by conducting tensile tests with both HERF samples and annealed samples.

Morgan, M.J.

1990-12-31T23:59:59.000Z

32

Search for the eta-mesic helium at COSY  

E-Print Network (OSTI)

We review status and perspectives of the search of the eta-mesic helium at the cooler synchrotron COSY.

P. Moskal

2009-09-22T23:59:59.000Z

33

Mantle helium and carbon isotopes in Separation Creek Geothermal Springs, Three Sisters area, Central Oregon: Evidence for renewed volcanic activity or a long term steady state system?  

DOE Green Energy (OSTI)

Cold bubbling springs in the Separation Creek area, the locus of current uplift at South Sister volcano show strong mantle signatures in helium and carbon isotopes and CO{sub 2}/{sup 3}He. This suggests the presence of fresh basaltic magma in the volcanic plumbing system. Currently there is no evidence to link this system directly to the uplift, which started in 1998. To the contrary, all geochemical evidence suggests that there is a long-lived geothermal system in the Separation Creek area, which has not significantly changed since the early 1990s. There was no archived helium and carbon data, so a definite conclusion regarding the strong mantle signature observed in these tracers cannot yet be drawn. There is a distinct discrepancy between the yearly magma supply required to explain the current uplift (0.006 km{sup 3}/yr) and that required to explain the discharge of CO{sub 2} from the system (0.0005 km{sup 3}/yr). This discrepancy may imply that the chemical signal associated with the increase in magma supply has not reached the surface yet. With respect to this the small changes observed at upper Mesa Creek require further attention, due to the recent volcanic vent in that area it may be the location were the chemical signal related to the uplift can most quickly reach the surface. Occurrence of such strong mantle signals in cold/diffuse geothermal systems suggests that these systems should not be ignored during volcano monitoring or geothermal evaluation studies. Although the surface-expression of these springs in terms of heat is minimal, the chemistry carries important information concerning the size and nature of the underlying high-temperature system and any changes taking place in it.

van Soest, M.C.; Kennedy, B.M.; Evans, W.C.; Mariner, R.H.

2002-04-30T23:59:59.000Z

34

ISOTOPES  

E-Print Network (OSTI)

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

35

It's Elemental - Isotopes of the Element Hydrogen  

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

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

36

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

Open Energy Info (EERE)

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

37

It's Elemental - The Element Helium  

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

to the atmosphere through cracks in the crust. Helium is commercially recovered from natural gas deposits, mostly from Texas, Oklahoma and Kansas. Helium gas is used to inflate...

38

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

Open Energy Info (EERE)

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

39

DEUTERIUM, TRITIUM, AND HELIUM DESORPTION FROM AGED TITANIUM TRITIDES. PART I.  

DOE Green Energy (OSTI)

Six new samples of tritium-aged bulk titanium have been examined by thermal desorption and isotope exchange chemistry. The discovery of a lower temperature hydrogen desorption state in these materials, previously reported, has been confirmed in one of the new samples. The helium release of the samples shows the more severe effects obtained from longer aging periods, i.e. higher initial He/M ratios. Several of the more aged samples were spontaneously releasing helium. Part I will discuss the new results on the new lower temperature hydrogen desorption state found in one more extensively studied sample. Part II will discuss the hydrogen/helium release behavior of the remaining samples.

Shanahan, K; Jeffrey Holder, J

2006-07-10T23:59:59.000Z

40

DEUTERIUM, TRITIUM, AND HELIUM DESORPTION FROM AGED TITANIUM TRITIDES. PART II.  

DOE Green Energy (OSTI)

Six new samples of tritium-aged bulk titanium have been examined by thermal desorption and isotope exchange chemistry. The discovery of a lower temperature hydrogen desorption state in these materials, previously reported, has been confirmed in one of the new samples. The helium release of the samples shows the more severe effects obtained from longer aging periods, i.e. higher initial He/M ratios. Several of the more aged samples were spontaneously releasing helium. Part I discussed the new results on the new lower temperature hydrogen desorption state found in one more extensively studied sample. Part II will discuss the hydrogen/helium release behavior of the remaining samples.

Shanahan, K; Jeffrey Holder, J

2006-08-17T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

Helium dilution refrigeration system  

DOE Patents (OSTI)

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains [sup 3]He and [sup 4]He liquids which are precooled by a coupled container containing [sup 3]He liquid, enabling the phase separation of a [sup 3]He rich liquid phase from a dilute [sup 3]He-[sup 4]He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the [sup 3]He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute [sup 3]He-[sup 4]He liquid phase. 2 figs.

Roach, P.R.; Gray, K.E.

1988-09-13T23:59:59.000Z

42

Laboratory and field-based instrumentation developments and noble gas-stable isotope systematics of Rungwe Volcanic Province, Iceland and the Central Indian Ridge  

E-Print Network (OSTI)

2005 Neon. Radiogenic isotope geology. p. 303. ISBN 978-0-Geology journal homepage: www.elsevier.com/locate/chemgeo Helium and carbon isotopeosmium isotope evidence from Canary Island lavas. Geology

Barry, Peter Hagan; Barry, Peter Hagan

2012-01-01T23:59:59.000Z

43

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

Open Energy Info (EERE)

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

44

Thermal integration of processes to recover helium  

SciTech Connect

New applications for helium have resulted in significant growth in helium demand in recent years. The primary source of helium in the USA is natural gas reservoirs. Typically natural gas reservoirs that contain helium also contain nitrogen. The presence of nitrogen requires that the heating value of the gas be upgraded using nitrogen rejection units (NRU). Thermal integration of the NRU process with the helium recovery process is described. Further integration of NRU and helium recovery process to produce cold helium gas suitable for use as a feed to a helium liquefier is also described. A key aspect of the integrated process is the use of refrigeration from the NRU to reduce power requirements, and capital cost for the helium recovery process.

Pahade, R.F.; Maloney, J.J.; Fisher, T.F. (Union Carbide Corp., Linde Div., Tonawanda, NY (US))

1988-01-01T23:59:59.000Z

45

Oxygen Isotopes  

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

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

46

Pulsed helium ionization detection system  

DOE Patents (OSTI)

A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

Ramsey, R.S.; Todd, R.A.

1985-04-09T23:59:59.000Z

47

Isotopic Analysis At Dixie Valley Geothermal Field Area (Kennedy & Van  

Open Energy Info (EERE)

Dixie Valley Geothermal Field Area (Kennedy & Van Dixie Valley Geothermal Field Area (Kennedy & Van Soest, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Dixie Valley Geothermal Field Area (Kennedy & Van Soest, 2005) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful DOE-funding Unknown Notes Dixie Valley study suggests that helium isotopes may provide a new tool for mapping zones of deep permeability and therefore the potential for high fluid temperatures. The permeable zones are identified by local enrichments in 3He relative to a regional helium isotope trend. More work needs to be done, but it appears that helium isotopes may provide the best and perhaps

48

Electric Dipole Polarizabilities of Hydrogen and Helium Isotopes  

E-Print Network (OSTI)

The electric dipole polarizabilities of $^3$H, $^3$He, and $^4$He are calculated directly using the Schr\\"odinger equation with the latest generation of two- and three-nucleon interactions. These polarizabilities are necessary in order to obtain accurate nuclear-polarization corrections for transitions involving S-waves in one- and two-electron atoms. Our results are compared to previous results, and it is shown that direct calculations of the electric polarizability of $^4$He using modern nuclear potentials are smaller than published values calculated using experimental photoabsorption data. The status of this topic is assessed in the context of precise measurements of transitions in one- and two-electron atoms.

I. Stetcu; S. Quaglioni; J. L. Friar; A. C. Hayes; P. Navrátil

2009-04-23T23:59:59.000Z

49

Electric dipole polarizabilities of hydrogen and helium isotopes  

DOE Green Energy (OSTI)

The electric dipole polarizabilities of {sup 3}H, {sup 3}He, and {sup 4}He are calculated directly using the Schroedinger equation with the latest generation of two- and three-nucleon interactions. These quantities are necessary in order to obtain accurate nuclear-polarization corrections for transitions involving S-waves in one-and two-electron atoms. Our results are compared to previous results, and it is shown that direct calculations of the electric polarizability of {sup 4}He using modern nuclear potentials are smaller than published values calculated using experimental photoabsorption data. The status of this topic is assessed in the context of precise measurements of transitions in one- and two-electron atoms.

Stetcu, I [Los Alamos National Laboratory; Friar, J [Los Alamos National Laboratory; Hayes, A C [Los Alamos National Laboratory; Quaglioni, S [LLNL

2009-01-01T23:59:59.000Z

50

Helium Isotopes In Geothermal And Volcanic Gases Of The Western...  

Open Energy Info (EERE)

a particular geothermal reservoir. Author(s): J. A. Welhan, R. J. Poredai, W. Rison, H. Craig Published: Journal of Volcanology and Geothermal Research, 1988 Document Number:...

51

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

Open Energy Info (EERE)

mixing, U-Th series alpha production and weathering release of crustal He, magma aging and tritiugenic addition of 3 He). Using this interpretational scheme, Iceland is...

52

Carbon Isotopes  

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

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

53

Precision spectroscopy of the helium atom.  

SciTech Connect

Persistent efforts in both theory and experiment have yielded increasingly precise understanding of the helium atom. Because of its simplicity, the helium atom has long been a testing ground for relativistic and quantum electrodynamic effects in few-body atomic systems theoretically and experimentally. Comparison between theory and experiment of the helium spectroscopy in 1s2p{sup 3}P{sub J} can potentially extract a very precise value of the fine structure constant a. The helium atom can also be used to explore exotic nuclear structures. In this paper, we provide a brief review of the recent advances in precision calculations and measurements of the helium atom.

Hu, S.-M.; Lu, Z.-T.; Yan, Z.-C.; Physics; Univ. of Science and Technology of China; Univ. of Chicago; Univ. of New Brunswick

2009-06-01T23:59:59.000Z

54

High-temperature helium-loop facility  

Science Conference Proceedings (OSTI)

The high-temperature helium loop is a facility for materials testing in ultrapure helium gas at high temperatures. The closed loop system is capable of recirculating high-purity helium or helium with controlled impurities. The gas loop maximum operating conditions are as follows: 300 psi pressure, 500 lb/h flow rate, and 2100/sup 0/F temperature. The two test sections can accept samples up to 3.5 in. diameter and 5 ft long. The gas loop is fully instrumented to continuously monitor all parameters of loop operation as well as helium impurities. The loop is fully automated to operate continuously and requires only a daily servicing by a qualified operator to replenish recorder charts and helium makeup gas. Because of its versatility and high degree of parameter control, the helium loop is applicable to many types of materials research. This report describes the test apparatus, operating parameters, peripheral systems, and instrumentation system.

Tokarz, R.D.

1981-09-01T23:59:59.000Z

55

In Beam Tests of Implanted Helium Targets  

E-Print Network (OSTI)

Targets consisting of 3,4He implanted into thin aluminum foils (approximately 100, 200 or 600 ug/cm^2) were prepared using intense (a few uA) helium beams at low energy (approximately 20, 40 or 100 keV). Uniformity of the implantation was achieved by a beam raster across a 12 mm diameter tantalum collimator at the rates of 0.1 Hz in the vertical direction and 1 Hz in the horizontal direction. Helium implantation into the very thin (approximately 80-100 ug/cm^2) aluminum foils failed to produce useful targets (with only approximately 10% of the helium retained) due to an under estimation of the range by the code SRIM. The range of low energy helium in aluminum predicted by Northcliffe and Shilling and the NIST online tabulation are observed on the other hand to over estimate the range of low energy helium ions in aluminum. An attempt to increase the amount of helium by implanting a second deeper layer was also carried out, but it did not significantly increase the helium content beyond the blistering limit (approximately 6 x 10^17 helium/cm^2). The implanted targets were bombarded with moderately intense 4He and 16O beams of 50-100 particle nA . Rutherford Back Scattering of 1.0 and 2.5 MeV proton beams and recoil helium from 15.0 MeV oxygen beams were used to study the helium content and profile before, during and after bombardments. We observed the helium content and profile to be very stable even after a prolonged bombardment (up to two days) with moderately intense beams of 16O or 4He. Helium implanted into thin (aluminum) foils is a good choice for thin helium targets needed, for example, for a measurement of the 3he(a,g)7Be reaction and the associated S34 astrophysical cross section factor (S-factor).

J. E. McDonald; R. H. France III; R. A. Jarvis; M. W. Ahmed; M. A. Blackston; Th. Delbar; M. Gai; T. J. Kading; Y. Parpottas; B. A. Perdue; R. M. Prior; D. A. Rubin; M. C. Spraker; J. D. Yeomans; L. Weissman; H. R. Weller; E. L. Wilds Jr; ;; UHartford; GCSU; LNS/UConn; TUNL/Duke; UCL/LLN; Yale; NGCSU

2006-08-16T23:59:59.000Z

56

Isotopic Analysis At Dixie Valley Geothermal Field Area (Kennedy & Van  

Open Energy Info (EERE)

Isotopic Analysis At Dixie Valley Geothermal Field Area (Kennedy & Van Isotopic Analysis At Dixie Valley Geothermal Field Area (Kennedy & Van Soest, 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Dixie Valley Geothermal Field Area (Kennedy & Van Soest, 2006) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful DOE-funding Unknown Notes Fluids from springs, fumaroles, and wells throughout Dixie Valley, NV were analyzed for noble gas abundances and isotopic compositions. The helium isotopic compositions of fluids produced from the Dixie Valley geothermal field range from 0.70 to 0.76 Ra, are among the highest values in the valley, and indicate that _7.5% of the total helium is derived from the

57

Iodine Stabilized Helium-Neon Laser  

Science Conference Proceedings (OSTI)

... stabilized lasers or spectral lamps that have been recommended for use by international consensus. The iodine stabilized helium-neon laser is just ...

58

Helium turbines for high-temperature reactors  

SciTech Connect

From joint meeting of the VDE and VDI; Dusseldorf, Ger. (17 Oct 1972). The designs of turbines with air and helium as working media are compared, and volume flow, mass flow, sound velocity, stage number, and other characteristics are individually dealt with. Similar comparisons are made regarding connecting lines and heat exchangers. The combination of the helium turbine with hightemperature reactors is described. Problems of the integrated and non- integrated method of single cycle plants and helium turbines, the use of dry cooling towers and the development of helium turbines are discussed. (GE)

Knuefer, H.

1973-12-01T23:59:59.000Z

59

Isotopic Analysis At Central Nevada Seismic Zone Region (Kennedy & Van  

Open Energy Info (EERE)

Isotopic Analysis At Central Nevada Seismic Zone Region (Kennedy & Van Isotopic Analysis At Central Nevada Seismic Zone Region (Kennedy & Van Soest, 2007) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Central Nevada Seismic Zone Region (Kennedy & Van Soest, 2007) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced permeability and that mantle fluids can penetrate the ductile lithosphere, even in regions where there is no substantial magmatism. Superimposed on the regional trend are local,

60

Fermilab Central Helium Liquefier Operations  

SciTech Connect

The Central Helium Liquefier (CHL), in conjunction with 24 satellite refrigerators, supplies refrigeration for the Fermilab superconducting accelerator. Liquid from the CHL is transported in a six kilometer circular transfer line and each satellite withdraws the amount required to boost its refrigeration capacity to the necessary level. Unused liquid is presently returned to compressor suction through a 250 kW calorimeter-heater. A helium gas flow of 1.1 kg/s is supplied to the cold box at 15 bars pressure. The gas flows through a demister and an oil adsorgber before it enters the cold box. In the cold box, manufactured by Koch Process Systems and Sulzer Brothers, Ltd., the gas is first cooled by liquid nitrogen and then the flow is split. Three quarters of the flow is further cooled by a series/parallel combination of three oil bearing turbines and then returned to the low pressure side of the heat exchangers. The return gas is used to cool the remaining high pressure gas which is then expanded to 3.5 bars in a 900 L receiver. From there the fluid is transferred into a distribution box, and then routed to either a collection dewar, directly to the ring, or to a heater. The liquid helium, which is utilized by the satellites to increase their cooling capacity, is warmed to near ambient temperature in the satellite heat exchangers. The satellite compressors return the excess inventory to the CHL via a 20 bar gas header. This gas is injected into the high pressure supply to the cold box. The system is shown.

Hodge, G.A.; Rihel, R.K.; Stone, M.E.; Walker, R.J.; /Fermilab

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

from Isotope Production Facility  

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

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

62

ENVIRONMENTAL PERSPECTIVES  

E-Print Network (OSTI)

.S. Department of Health and Human Services Assessing the Ecotoxicologic Hazards of a Pandemic Influenza MedicalENVIRONMENTAL HEALTH PERSPECTIVES ENVIRONMENTAL HEALTH PERSPECTIVES National Institutes of Health U75012, France 4 Computational Epidemiology Laboratory, Institute for Scientific Interchange, Turin

Cattuto, Ciro

63

Modernizing helium liquefier G-3  

SciTech Connect

The authors describe the process for modernizing the existing liquefier with minimum alteration of its cooling block, that liquefier being helium expansion-type liquefier G-3, made at the Institute of Physical Problems, Academy of Sciences of the USSR, which operates at a stable output of 40 liters/h. A nitrogen tank and a pistontype expander in the preliminary cooling stages and a throttle in the liquefaction stages are used in G-3. Improving the efficiency of such a cooling cycle is limited by the fact that the optimal parameters of throttle stage of liquefaction do not match with the optimal parameters of the expander in the preliminary cooling stages. Thus, for improving cycle efficiency the pressure in the preliminary stages must be increased but reduced in the liquefaction stage. This paper also presents the solution to this problem. It is further demonstrated that the use of vapor-liquid expander in the liquefaction stage of helium cooling cycle helps increase the output of the unit by 40% in a relatively simple way.

Golikov, G.E.; Danilov, I.B.

1985-02-01T23:59:59.000Z

64

Focused helium ion beam milling and deposition  

Science Conference Proceedings (OSTI)

The use of a helium ion microscope with an integrated gas injection system for nanofabrication is explored by demonstrating the milling of fine features into single layered graphene and the controlled deposition of tungsten and platinum wires from gaseous ... Keywords: Beam-induced deposition, Focused ion beam, Gas injection system, Graphene, Helium ion microscope

S. A. Boden; Z. Moktadir; D. M. Bagnall; H. Mizuta; H. N. Rutt

2011-08-01T23:59:59.000Z

65

Helium measurements of pore-fluids obtained from SAFOD drillcore  

SciTech Connect

{sup 4}He accumulated in fluids is a well established geochemical tracer used to study crustal fluid dynamics. Direct fluid samples are not always collectable; therefore, a method to extract rare gases from matrix fluids of whole rocks by diffusion has been adapted. Helium was measured on matrix fluids extracted from sandstones and mudstones recovered during the San Andreas Fault Observatory at Depth (SAFOD) drilling in California, USA. Samples were typically collected as subcores or from drillcore fragments. Helium concentration and isotope ratios were measured 4-6 times on each sample, and indicate a bulk {sup 4}He diffusion coefficient of 3.5 {+-} 1.3 x 10{sup -8} cm{sup 2}s{sup -1} at 21 C, compared to previously published diffusion coefficients of 1.2 x 10{sup -18} cm{sup 2}s{sup -1} (21 C) to 3.0 x 10{sup -15} cm{sup 2}s{sup -1} (150 C) in the sands and clays. Correcting the diffusion coefficient of {sup 4}He{sub water} for matrix porosity ({approx}3%) and tortuosity ({approx}6-13) produces effective diffusion coefficients of 1 x 10{sup -8} cm{sup 2}s{sup -1} (21 C) and 1 x 10{sup -7} (120 C), effectively isolating pore fluid {sup 4}He from the {sup 4}He contained in the rock matrix. Model calculations indicate that <6% of helium initially dissolved in pore fluids was lost during the sampling process. Complete and quantitative extraction of the pore fluids provide minimum in situ porosity values for sandstones 2.8 {+-} 0.4% (SD, n=4) and mudstones 3.1 {+-} 0.8% (SD, n=4).

Ali, S.; Stute, M.; Torgersen, T.; Winckler, G.; Kennedy, B.M.

2010-04-15T23:59:59.000Z

66

ISOTOPE SEPARATORS  

DOE Patents (OSTI)

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

Bacon, C.G.

1958-08-26T23:59:59.000Z

67

Isotopic Analysis-Fluid At Steamboat Springs Geothermal Area (1982) | Open  

Open Energy Info (EERE)

Isotopic Analysis-Fluid At Steamboat Springs Geothermal Area (1982) Isotopic Analysis-Fluid At Steamboat Springs Geothermal Area (1982) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-Fluid At Steamboat Springs Geothermal Area (1982) Exploration Activity Details Location Steamboat Springs Geothermal Area Exploration Technique Isotopic Analysis-Fluid Activity Date 1982 Usefulness not indicated DOE-funding Unknown Notes Helium isotope ratios have been measured in geothermal fluids. These ratios have been interpreted in terms of the processes which supply He in distinct isotopic ratios (i.e. magmatic He, ~10 Ra; atmospheric He, Ra; and crustal He, ~0.1 Ra) and in terms of the processes which can alter the isotopic ratio (hydrologic mixing, U-Th series alpha production and weathering

68

NIDC: Online Catalog of Isotope Products | Product List  

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

List List Please select an available isotope product from the lists below. If you would like an isotope product that is not listed, you can make a request by clicking here. Stable Isotope Products Radio-Isotope Products Antimony Argon (Alt) Barium Bromine Bromine (Alt) Cadmium Calcium Carbon (Alt) Cerium Chlorine Chlorine (Alt) Chromium Copper Dysprosium Erbium Europium Gadolinium Gallium Germanium Hafnium Helium (Alt) Indium Iridium Iron Krypton (Alt) Lanthanum Lead Lithium Lutetium Magnesium Mercury Molybdenum Neodymium Neon (Alt) Nickel Nitrogen (Alt) Osmium Oxygen (Alt) Palladium Platinum Potassium Rhenium Rubidium Ruthenium Samarium Selenium Silicon Silver Strontium Sulfur Sulfur (Alt) Tantalum Tellurium Thallium Tin Titanium Tungsten Vanadium Xenon (Alt) Ytterbium Zinc Zirconium Actinium-225 Aluminum-26 Americium-241

69

Helium measurements of pore-fluids obtained from SAFOD drillcore  

Science Conference Proceedings (OSTI)

{sup 4}He accumulated in fluids is a well established geochemical tracer used to study crustal fluid dynamics. Direct fluid samples are not always collectable; therefore, a method to extract rare gases from matrix fluids of whole rocks by diffusion has been adapted. Helium was measured on matrix fluids extracted from sandstones and mudstones recovered during the San Andreas Fault Observatory at Depth (SAFOD) drilling in California, USA. Samples were typically collected as subcores or from drillcore fragments. Helium concentration and isotope ratios were measured 4-6 times on each sample, and indicate a bulk {sup 4}He diffusion coefficient of 3.5 {+-} 1.3 x 10{sup -8} cm{sup 2}s{sup -1} at 21 C, compared to previously published diffusion coefficients of 1.2 x 10{sup -18} cm{sup 2}s{sup -1} (21 C) to 3.0 x 10{sup -15} cm{sup 2}s{sup -1} (150 C) in the sands and clays. Correcting the diffusion coefficient of {sup 4}He{sub water} for matrix porosity ({approx}3%) and tortuosity ({approx}6-13) produces effective diffusion coefficients of 1 x 10{sup -8} cm{sup 2}s{sup -1} (21 C) and 1 x 10{sup -7} (120 C), effectively isolating pore fluid {sup 4}He from the {sup 4}He contained in the rock matrix. Model calculations indicate that fluids was lost during the sampling process. Complete and quantitative extraction of the pore fluids provide minimum in situ porosity values for sandstones 2.8 {+-} 0.4% (SD, n=4) and mudstones 3.1 {+-} 0.8% (SD, n=4).

Ali, S.; Stute, M.; Torgersen, T.; Winckler, G.; Kennedy, B.M.

2010-04-15T23:59:59.000Z

70

Dynamic Simulation of a Helium Liquefier  

SciTech Connect

Dynamic behavior of a helium liquefier has been studied in detail with a Cryogenic Process REal-time SimulaTor (C-PREST) at the National Institute for Fusion Science (NIFS). The C-PREST is being developed to integrate large-scale helium cryogenic plant design, operation and maintenance for optimum process establishment. As a first step of simulations of cooldown to 4.5 K with the helium liquefier model is conducted, which provides a plant-process validation platform. The helium liquefier consists of seven heat exchangers, a liquid-nitrogen (LN2) precooler, two expansion turbines and a liquid-helium (LHe) reservoir. Process simulations are fulfilled with sequence programs, which were implemented with C-PREST based on an existing liquefier operation. The interactions of a JT valve, a JT-bypass valve and a reservoir-return valve have been dynamically simulated. The paper discusses various aspects of refrigeration process simulation, including its difficulties such as a balance between complexity of the adopted models and CPU time.

Maekawa, R.; Ooba, K.; Mito, T. [National Institute for Fusion Science, Toki, Gifu, 509-5292 (Japan); Nobutoki, M. [Nippon Sanso Co., Kawasaki, Kanagawa, 210-0861 (Japan)

2004-06-23T23:59:59.000Z

71

Helium release from radioisotope heat sources  

DOE Green Energy (OSTI)

Diffusion of helium in /sup 238/PuO/sub 2/ fuel was characterized as a function of the heating rate and the fuel microstructure. The samples were thermally ramped in an induction furnace and the helium release rates measured with an automated mass spectrometer. The diffusion constants and activation energies were obtained from the data using a simple diffusion model. The release rates of helium were correlated with the fuel microstructure by metallographic examination of fuel samples. The release mechanism consists of four regimes, which are dependent upon the temperature. Initially, the release is controlled by movement of point defects combined with trapping along grain boundaries. This regime is followed by a process dominated by formation and growth of helium bubbles along grain boundaries. The third regime involves volume diffusion controlled by movement of oxygen vacancies. Finally, the release at the highest temperatures follows the diffusion rate of intragranular bubbles. The tendency for helium to be trapped within the grain boundaries diminishes with small grain sizes, slow thermal pulses, and older fuel.

Peterson, D.E.; Early, J.W.; Starzynski, J.S.; Land, C.C.

1984-05-01T23:59:59.000Z

72

Glossary Term - Isotope  

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

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

73

Helium-filled aluminum flight tubes  

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

Helium-filled aluminum flight tubes. Helium-filled aluminum flight tubes. Detector housing for the CCD camera lens, mirror, and scintillator. For more information, contact Instrument Scientist: Hassina Bilheux, bilheuxhn@ornl.gov, 865.384.9630 neutrons.ornl.gov/instruments/HFIR/factsheets/Instrument-cg1d.pdf The CG-1D beam is used for neutron imaging measurements using a white beam. Apertures (with different diameters D (pinhole geometry) are used at the entrance of the helium-filled flight path to allow L/D variation from 400 to 800. L is the distance between the aperture and the detector (where the image is produced). Samples sit on a translation/ rotation stage for alignment and tomography purposes. Detectors for CG-1D include

74

SCREW COMPRESSOR CHARACTERISTICS FOR HELIUM REFRIGERATION SYSTEMS  

SciTech Connect

The oil injected screw compressors have practically replaced all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, minimal vibration, reliability and capability of handling helium's high heat of compression.At the present state of compressor system designs for helium systems, typically two-thirds of the lost input power is due to the compression system. Therefore it is important to understand the isothermal and volumetric efficiencies of these machines to help properly design these compression systems to match the refrigeration process. This presentation summarizes separate tests that have been conducted on Sullair compressors at the Superconducting Super-Collider Laboratory (SSCL) in 1993, Howden compressors at Jefferson Lab (JLab) in 2006 and Howden compressors at the Spallation Neutron Source (SNS) in 2006. This work is part of an ongoing study at JLab to understand the theoretical basis for these efficiencies and their loss

Ganni, Venkatarao; Knudsen, Peter; Creel, Jonathan; Arenius, Dana; Casagrande, Fabio; Howell, Matt

2008-03-01T23:59:59.000Z

75

Properties of hydrogen/helium accretion plasmas  

DOE Green Energy (OSTI)

We study the properties of impulsively-heated plasmas initially composed of hydrogen and helium. We follow the time-dependent behavior of the ion and electron temperatures, the pair density, and the densities of hydrogen, helium, and nuclei formed in fusion and breakup reactions. We also consider neutron production and escape, and calculate the 0.431 and 0.478 MeV line luminosities from ..cap alpha..-..cap alpha.. fusion reactions, and the 2.22 MeV line luminosity from neutron capture on protons. 13 refs., 3 figs., 1 tab.

Guessoum, N.; Dermer, C.D.

1988-02-01T23:59:59.000Z

76

Tritium-Helium Effects in Metals  

Science Conference Proceedings (OSTI)

Material Interaction / Proceedings of the Second National Topical Meeting on Tritium Technology in Fission, Fusion and Isotopic Applications (Dayton, Ohio, April 30 to May 2, 1985)

G. R. Caskey; Jr.

77

Isotopic Analysis At Separation Creek Area (Van Soest, Et Al., 2002) | Open  

Open Energy Info (EERE)

Isotopic Analysis At Separation Creek Area (Van Soest, Et Al., 2002) Isotopic Analysis At Separation Creek Area (Van Soest, Et Al., 2002) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Separation Creek Area (Van Soest, Et Al., 2002) Exploration Activity Details Location Separation Creek Area Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful DOE-funding Unknown References M. C. van Soest, B. M. Kennedy, W. C. Evans, R. H. Mariner (2002) Mantle Helium And Carbon Isotopes In Separation Creek Geothermal Springs, Three Sisters Area, Central Oregon- Evidence For Renewed Volcanic Activity Or A Long Term Steady State System(Question) Retrieved from "http://en.openei.org/w/index.php?title=Isotopic_Analysis_At_Separation_Creek_Area_(Van_Soest,_Et_Al.,_2002)&oldid=687475"

78

Isotopic Analysis-Fluid At Raft River Geothermal Area (1982) | Open Energy  

Open Energy Info (EERE)

Analysis-Fluid At Raft River Geothermal Area Analysis-Fluid At Raft River Geothermal Area (1982) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Isotopic Analysis- Fluid Activity Date 1982 Usefulness not useful DOE-funding Unknown Exploration Basis Determine which reservoir model best matches the isotope data. Notes 1) Chemical and light-stable isotope data are presented for water samples from the Raft River geothermal area and nearby. On the basis of chemical character, as defined by a trilinear plot of per cent milliequivalents, and light-stable isotope data, the waters in the geothermal area can be divided into waters that have and have not mixed with cold water. 2) Helium isotope ratios have been measured in geothermal fluids. These ratios have been interpreted in terms of the processes which supply He in distinct isotopic

79

STUDY OF HELIUM RETENTION IN NANO-CAVITY ...  

Science Conference Proceedings (OSTI)

STUDY OF HELIUM RETENTION IN NANO-CAVITY TUNGSTEN AS A FIRST WALL IN A FUSION CHAMBER USING NEUTRON DEPTH ...

80

Stable isotope studies  

SciTech Connect

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

Ishida, T.

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

Method for separating isotopes  

DOE Patents (OSTI)

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

Jepson, B.E.

1975-10-21T23:59:59.000Z

82

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

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

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

83

Isotope separation by photochromatography  

DOE Patents (OSTI)

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

Suslick, Kenneth S. (Stanford, CA)

1977-01-01T23:59:59.000Z

84

Isotopic Analysis At Walker-Lane Transitional Zone Region (Kennedy & Van  

Open Energy Info (EERE)

Kennedy & Van Kennedy & Van Soest, 2007) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Walker-Lane Transitional Zone Region (Kennedy & Van Soest, 2007) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced permeability and that mantle fluids can penetrate the ductile lithosphere, even in regions where there is no substantial magmatism. Superimposed on the regional trend are local, high 3He/4He anomalies indicating hidden magmatic activity and/or deep

85

Time dependence of liquid-helium fluorescence  

SciTech Connect

The time dependence of extreme ultraviolet (EUV) fluorescence following an ionizing radiation event in liquid helium is observed and studied in the temperature range from 250 mK to 1.8 K. The fluorescence exhibits significant structure including a short ({approx}10 ns) strong initial pulse followed by single photons whose emission rate decays exponentially with a 1.6-{mu}s time constant. At an even longer time scale, the emission rate varies as '1/time' (inversely proportional to the time after the initial pulse). The intensity of the '1/time' component from {beta} particles is significantly weaker than those from {alpha} particles or neutron capture on {sup 3}He. It is also found that for {alpha} particles, the intensity of this component depends on the temperature of the superfluid helium. Proposed models describing the observed fluorescence are discussed.

McKinsey, D.N.; Brome, C.R.; Dzhosyuk, S.N.; Mattoni, C.E.H.; Yang, L.; Doyle, J.M. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); Golub, R.; Habicht, K.; Korobkina, E. [Hahn-Meitner Institut, Berlin-Wannsee (Germany); Huffman, P.R.; Thompson, A.K. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Lamoreaux, S.K. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

2003-06-01T23:59:59.000Z

86

Combined cold compressor/ejector helium refrigerator  

DOE Patents (OSTI)

A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

Brown, Donald P. (Southold, NY)

1985-01-01T23:59:59.000Z

87

Studies of Helium Distribution in Metal Tritides  

SciTech Connect

The distribution of helium (3HE) in LiT, TiT2, and UT3, which are regarded as representative metal tritides, was investigated using pulse nuclear magnetic resonance (NMR) techniques. Analyses of the NMR lineshapes and nuclear relaxation times indicate the 3He atoms are trapped in microscopic gas bubbles for each tritide. The effects of concentration and temperature on the 3He distributions were investigated as well.

Bowman, Jr., R. C.; Attalla, A.

1976-03-01T23:59:59.000Z

88

Combined cold compressor/ejector helium refrigerator  

DOE Patents (OSTI)

A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

Brown, D.P.

1984-06-05T23:59:59.000Z

89

Hydrogen Production Using the Modular Helium Reactor  

DOE Green Energy (OSTI)

The high-temperature characteristics of the Modular Helium Reactor (MHR) make it a strong candidate for the production of hydrogen using either thermochemical or high-temperature electrolysis (HTE) processes. Using heat from the MHR to drive a Sulfur-Iodine (S-I) thermochemical hydrogen process has been the subject of a DOE sponsored Nuclear Engineering Research Initiative (NERI) project lead by General Atomics, with participation from the Idaho National Engineering and Environmental Laboratory (INEEL) and Texas A&M University. While the focus of much of the initial work was on the S-I thermochemical production of hydrogen, recent activities have also included development of a preconceptual design for an integral HTE hydrogen production plant driven by the process heat and electricity produced by a 600 MWt MHR. This paper describes RELAP5-3D analyses performed to evaluate alternative primary system cooling configurations for the MHR to minimize peak reactor vessel and core temperatures while achieving core helium outlet temperatures in the range of 900 oC to 1000 oC, needed for the efficient production of hydrogen using either the S-I thermochemical or HTE process. The cooling schemes investigated are intended to ensure peak fuel temperatures do not exceed specified limits under normal or transient upset conditions, and that reactor vessel temperatures do not exceed ASME code limits for steady-state or transient conditions using standard LWR vessel materials. Preconceptual designs for both an S-I thermochemical and HTE hydrogen production plant driven by a 600 MWt MHR at helium outlet temperatures in the range of 900 oC to 1000 oC are described and compared. An initial SAPHIRE model to evaluate the reliability, maintainablility, and availability of the S-I hydrogen production plant is also discussed, and plans for future assessments of conceptual designs for both a S-I thermochemical and HTE hydrogen production plant coupled to a 600 MWt modular helium reactor are described.

E. A. Harvego; S. M. Reza; M. Richards; A. Shenoy

2005-05-01T23:59:59.000Z

90

The Helium spectrum in erupting solar prominences  

E-Print Network (OSTI)

Even quiescent solar prominences may become active and sometimes erupt. These events are occasionally linked to coronal mass ejections. However we know very little about the plasma properties during the activation and eruption processes. We present new computations of the helium line profiles emitted by an eruptive prominence. The prominence is modelled as a plane-parallel slab standing vertically above the solar surface and moving upward as a solid body. The helium spectrum is computed with a non local thermodynamic equilibrium radiative transfer code. The effect of Doppler dimming / brightening is investigated in the resonance lines of He I and He II formed in the EUV, as well as on the He I 10830 A and 5876 A lines. We focus on the line profile properties and the resulting integrated intensities. It is shown that the helium lines are very sensitive to Doppler dimming effects. We also study the effect of frequency redistribution in the formation mechanisms of the resonance lines and find that it is necessary to use partial redistribution in frequency for the resonance lines.

Nicolas Labrosse; Pierre Gouttebroze; Jean-Claude Vial

2006-09-18T23:59:59.000Z

91

Isotopic Analysis-Fluid At Geysers Geothermal Area (1982) | Open Energy  

Open Energy Info (EERE)

82) 82) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-Fluid At Geysers Geothermal Area (1982) Exploration Activity Details Location Geysers Geothermal Area Exploration Technique Isotopic Analysis-Fluid Activity Date 1982 Usefulness not indicated DOE-funding Unknown Notes Helium isotope ratios have been measured in geothermal fluids. These ratios have been interpreted in terms of the processes which supply He in distinct isotopic ratios (i.e. magmatic He, ~10 Ra; atmospheric He, Ra; and crustal He, ~0.1 Ra) and in terms of the processes which can alter the isotopic ratio (hydrologic mixing, U-Th series alpha production and weathering release of crustal He, magma aging and tritiugenic addition of 3He). Raft

92

Isotope Enrichment Calculator  

Science Conference Proceedings (OSTI)

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

2012-10-09T23:59:59.000Z

93

Production of 26Al, 44Ti and 60Fe in Supernovae-sensitivity to the helium burning rates  

E-Print Network (OSTI)

We have studied the sensitivity of supernova production of the gamma emitting nuclei 26Al, 44Ti and 60Fe to variations of the rates of the triple alpha and 12C(alpha, gamma) reactions. Over a range of twice their experimental uncertainties we find variations in the production of 60Fe by more than a factor of five. Smaller variations, about a factor of two to three, were observed for 26Al and 44Ti. The yields of these isotopes change significantly when the abundances of Lodders (2003) are used instead of those of Anders and Grevesse (1989). These sensitivities will limit conclusions based on a comparison of observed gamma ray intensities and stellar models until the helium burning rates are better known. Prospects for improving the helium burning rates are discussed and a new version of the Boyes rate for 12C(alpha, gamma} is presented.

Clarisse Tur; Alexander Heger; Sam M. Austin

2010-12-21T23:59:59.000Z

94

Trace Detection of Metastable Helium Molecules in Superfluid Helium by Laser-Induced Fluorescence  

SciTech Connect

We describe an approach to detecting ionizing radiation that combines the special properties of superfluid helium with the sensitivity of quantum optics techniques. Ionization in liquid helium results in the copious production of metastable He{sub 2} molecules, which can be detected by laser-induced fluorescence. Each molecule can be probed many times using a cycling transition, resulting in the detection of individual molecules with high signal to noise. This technique could be used to detect neutrinos, weakly interacting massive particles, and ultracold neutrons, and to image superfluid flow in liquid {sup 4}He.

McKinsey, D. N.; Lippincott, W.H.; Nikkel, J.A.; Rellergert, W.G. [Department of Physics, Yale University, P.O. Box 208120, New Haven, Connecticut 06520 (United States)

2005-09-09T23:59:59.000Z

95

The Potential of Helium as a Guide to Uranium Ore  

Science Conference Proceedings (OSTI)

Martin Marietta Corp. and Earth Sciences, Inc., studied the effectiveness of helium surveying as a tool for uranium exploration. They generated basic data on the little-known distribution of helium in soils, tested various techniques for conducting surveys in the field, developed guidelines for helium surveys and interpretation, and stimulated interest, if it was warranted, in the further testing and application of promising approaches.

1978-07-01T23:59:59.000Z

96

Isotopically controlled semiconductors  

SciTech Connect

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

Haller, Eugene E.

2001-12-21T23:59:59.000Z

97

ISOTOPE CONVERSION DEVICE  

DOE Patents (OSTI)

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

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

1957-12-01T23:59:59.000Z

98

The Helium-3 Supply Crisis – Alternative Techniques to ...  

Science Conference Proceedings (OSTI)

... Helium-3 is a by-product of tritium decay after 12 years. Due to the nonetheless encouraging reduction in stocks of tritium ...

2010-04-16T23:59:59.000Z

99

NIST Studies How New Helium Ion Microscope Measures Up  

Science Conference Proceedings (OSTI)

... are studying helium ion microscopes to improve ... analogous to the scanning electron microscope, which was ... are far larger than electrons, they can ...

2012-11-02T23:59:59.000Z

100

ARM - Measurement - Isotope ratio  

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

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

Note: This page contains sample records for the topic "helium isotope perspective" 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

Simulation program for central helium liquefier  

SciTech Connect

The computer program described here analyzes the performance of Fermilab Central Helium Liquefier (CHL) and predicts the values of the plant thermodynamic variables at all process points in the plant. To simulate CHL, this program is modified from the prototype program which was developed by Hitachi Ltd. a couple of years ago. This program takes care of only the steady state simulation and takes account of the change of the turbine efficiency, the pressure drops and the UA values of the heat exchangers. How to use the program is shown.

Kawamura, S.

1984-02-20T23:59:59.000Z

102

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

Science Conference Proceedings (OSTI)

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

Jewett, J.R., Fluor Daniel Hanford

1997-02-24T23:59:59.000Z

103

Liquid uranium alloy-helium fission reactor  

DOE Patents (OSTI)

This invention describes a nuclear fission reactor which has a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200 to 1800/sup 0/C range, and even higher to 2500/sup 0/C.

Minkov, V.

1984-06-13T23:59:59.000Z

104

Liquid uranium alloy-helium fission reactor  

SciTech Connect

This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree. C., limited only by the thermal effectiveness of the structural materials, increasing the efficiency of power generation from the normal 30-35% with 300.degree.-500.degree. C. upper limit temperature to 50-65%. Irradiation of the circulating liquid fuel, as contrasted to only localized irradiation of a solid fuel, provides improved fuel utilization.

Minkov, Vladimir (Skokie, IL)

1986-01-01T23:59:59.000Z

105

DIRECT EVALUATION OF THE HELIUM ABUNDANCES IN OMEGA CENTAURI  

SciTech Connect

A direct measure of the helium abundances from the near-infrared transition of He I at 1.08 {mu}m is obtained for two nearly identical red giant stars in the globular cluster Omega Centauri. One star exhibits the He I line; the line is weak or absent in the other star. Detailed non-local thermal equilibrium semi-empirical models including expansion in spherical geometry are developed to match the chromospheric H{alpha}, H{beta}, and Ca II K lines, in order to predict the helium profile and derive a helium abundance. The red giant spectra suggest a helium abundance of Y {<=} 0.22 (LEID 54064) and Y = 0.39-0.44 (LEID 54084) corresponding to a difference in the abundance {Delta}Y {>=} 0.17. Helium is enhanced in the giant star (LEID 54084) that also contains enhanced aluminum and magnesium. This direct evaluation of the helium abundances gives observational support to the theoretical conjecture that multiple populations harbor enhanced helium in addition to light elements that are products of high-temperature hydrogen burning. We demonstrate that the 1.08 {mu}m He I line can yield a helium abundance in cool stars when constraints on the semi-empirical chromospheric model are provided by other spectroscopic features.

Dupree, A. K.; Avrett, E. H., E-mail: dupree@cfa.harvard.edu, E-mail: eavrett@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2013-08-20T23:59:59.000Z

106

Hybrid isotope separation scheme  

DOE Patents (OSTI)

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

Maya, Jakob (Brookline, MA)

1991-01-01T23:59:59.000Z

107

HYDROGEN ISOTOPE TARGETS  

DOE Patents (OSTI)

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

Ashley, R.W.

1958-08-12T23:59:59.000Z

108

Helium measurements of pore-fluids obtained from SAFOD drillcore  

E-Print Network (OSTI)

isotope studies in the Mojave Desert, California: implications for groundwater chronology and regional seismicity." Chemical Geology

Ali, S.

2010-01-01T23:59:59.000Z

109

Manufacturing Perspective  

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

EOT_RT_Sub_Template.ppt | 1/6/2009 | 1 EOT_RT_Sub_Template.ppt | 1/6/2009 | 1 BOEING is a trademark of Boeing Management Company. Copyright © 2009 Boeing. All rights reserved. Compressed Hydrogen Storage Workshop Manufacturing Perspective Karl M. Nelson (karl.m.nelson@boeing.com) Boeing Research & Technology Engineering, Operations & Technology | Boeing Research & Technology Materials & Fabrication Technology EOT_RT_Sub_Template.ppt | 1/12/2009 | Structural Tech 2 Copyright © 2009 Boeing. All rights reserved. DOE Hydrogen Program Development of Advanced Manufacturing Technologies for Low Cost Hydrogen Storage Vessels Mark Leavitt, Alex Ly Quantum Fuel Systems Technologies Worldwide Inc. Karl Nelson, Brice Johnson The Boeing Company Ken Johnson, Kyle Alvine, Stan Pitman, Michael Dahl, Daryl Brown

110

Industry Perspective  

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

idatech.com idatech.com info@idatech.com 63065 NE 18 th Street Bend, OR 97701 541.383.3390 Industry Perspective Biogas and Fuel Cell Workshop National Renewable Energy Laboratory June 11 - 13, 2012 Mike Hicks Chairman of the Board of Directors, FCHEA Treasurer of the Board of Directors, FCS&E Engineering Manager, Technology Development & Integration, IdaTech Outline 1. Critical Factors * Fuel Purity * Fuel Cost 2. Natural Gas - The Wild Card & Competition 3. IdaTech's Experience Implementing Biofuel Critical Factor - Fuel Purity All fuel cell system OEMs have fuel purity specifications * Independent of * Raw materials or feed stocks * Manufacturing process * Depends on * Fuel processor technology * Fuel cell technology - low temp PEM versus SOFC

111

Discovery of the Mercury Isotopes  

E-Print Network (OSTI)

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

D. Meierfrankenfeld; M. Thoennessen

2009-12-01T23:59:59.000Z

112

Superconducting cable cooling system by helium gas and a mixture of gas and liquid helium  

DOE Patents (OSTI)

Thermally contacting, oppositely streaming cryogenic fluid streams in the same enclosure in a closed cycle that changes from a cool high pressure helium gas to a cooler reduced pressure helium fluid comprised of a mixture of gas and boiling liquid so as to be near the same temperature but at different pressures respectively in go and return legs that are in thermal contact with each other and in thermal contact with a longitudinally extending superconducting transmission line enclosed in the same cable enclosure that insulates the line from the ambient at a temperature T.sub.1. By first circulating the fluid in a go leg from a refrigerator at one end of the line as a high pressure helium gas near the normal boiling temperature of helium; then circulating the gas through an expander at the other end of the line where the gas becomes a mixture of reduced pressure gas and boiling liquid at its boiling temperature; then by circulating the mixture in a return leg that is separated from but in thermal contact with the gas in the go leg and in the same enclosure therewith; and finally returning the resulting low pressure gas to the refrigerator for compression into a high pressure gas at T.sub.2 is a closed cycle, where T.sub.1 >T.sub.2, the temperature distribution is such that the line temperature is nearly constant along its length from the refrigerator to the expander due to the boiling of the liquid in the mixture. A heat exchanger between the go and return lines removes the gas from the liquid in the return leg while cooling the go leg.

Dean, John W. (Los Alamos, NM)

1977-01-01T23:59:59.000Z

113

Testing CPT Invariance with Antiprotonic Helium Atoms  

Science Conference Proceedings (OSTI)

The structure of matter is related to symmetries at every level of study. CPT symmetry is one of the most important laws of field theory: it states the invariance of physical properties when one simultaneously changes the signs of the charge and of the spatial and time coordinates of free elementary particles. Although in general opinion CPT symmetry is not violated in Nature, there are theoretical attempts to develop CPT-violating models. The Antiproton Decelerator at CERN has been built to test CPT invariance. The ASACUSA experiment compares the properties of particles and antiparticles by studying the antiprotonic helium atom via laser spectroscopy and measuring the mass, charge and magnetic moment of the antiproton as compared to those of the proton.

Horvath, Dezso [KFKI Research Institute for Particle and Nuclear Physics, H-1525 Budapest, Hungary and Institute of Nuclear Research (ATOMKI), Debrecen (Hungary)

2008-08-08T23:59:59.000Z

114

ACOUSTIC SIGNATURES OF THE HELIUM CORE FLASH  

SciTech Connect

All evolved stars with masses M {approx}< 2 M{sub Sun} undergo an initiating off-center helium core flash in their M{sub c} Almost-Equal-To 0.48 M{sub Sun} He core as they ascend the red giant branch (RGB). This off-center flash is the first of a few successive helium shell subflashes that remove the core electron degeneracy over 2 Myr, converting the object into a He-burning star. Though characterized by Thomas over 40 years ago, this core flash phase has yet to be observationally probed. Using the Modules for Experiments in Stellar Astrophysics (MESA) code, we show that red giant asteroseismology enabled by space-based photometry (i.e., Kepler and CoRoT) can probe these stars during the flash. The rapid ({approx}< 10{sup 5} yr) contraction of the red giant envelope after the initiating flash dramatically improves the coupling of the p-modes to the core g-modes, making the detection of l = 1 mixed modes possible for these 2 Myr. This duration implies that 1 in 35 stars near the red clump in the H-R diagram will be in their core flash phase. During this time, the star has a g-mode period spacing of {Delta}P{sub g} Almost-Equal-To 70-100 s, lower than the {Delta}P{sub g} Almost-Equal-To 250 s of He-burning stars in the red clump, but higher than the RGB stars at the same luminosity. This places them in an underpopulated part of the large frequency spacing ({Delta}{nu}) versus {Delta}P{sub g} diagram that should ease their identification among the thousands of observed red giants.

Bildsten, Lars; Paxton, Bill; Moore, Kevin; Macias, Phillip J. [Kavli Institute for Theoretical Physics and Department of Physics Kohn Hall, University of California, Santa Barbara, CA 93106 (United States)

2012-01-15T23:59:59.000Z

115

Fuel Cycle and Isotopes Division  

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

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

116

Isotopic Analysis | Open Energy Information  

Open Energy Info (EERE)

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

117

Isotope Enrichment | ornl.gov  

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

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

118

Laser isotope separation  

DOE Patents (OSTI)

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

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

1975-11-26T23:59:59.000Z

119

Isotope GeochemistryIsotope Geochemistry Isotopes do not fractionate during partial  

E-Print Network (OSTI)

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

Siebel, Wolfgang

120

Evolution of the Standard Helium Liquefier and Refrigerator Range designed by Air Liquide DTA, France  

E-Print Network (OSTI)

Evolution of the Standard Helium Liquefier and Refrigerator Range designed by Air Liquide DTA, France

Crispel, S; Caillaud, A; Delcayre, F; Grabie, V

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

Transient Behaviour and Helium Discharge in Cryogenic Distribution Line (QRL) Headers Following Breakdown of Insulation Vacuum  

E-Print Network (OSTI)

Transient Behaviour and Helium Discharge in Cryogenic Distribution Line (QRL) Headers Following Breakdown of Insulation Vacuum

Chorowski, M

1997-01-01T23:59:59.000Z

122

Isotopically controlled semiconductors  

SciTech Connect

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

Haller, Eugene E.

2006-06-19T23:59:59.000Z

123

Isotopes of helium, hydrogen, and carbon as groundwater tracers in aquifers along the Colorado River  

E-Print Network (OSTI)

Survey Data Series. Google.com Maps, 2009 Ground Water Atlasand Yuma highlighted. (Google.com) NEEDLES Eagle Peak 2 kmto furthest from river. (Google.com) BLYTHE 5km Figure 6:

Haber, Samuel Ainsworth

2009-01-01T23:59:59.000Z

124

Spallation-Fission Competition in Heaviest Elements; Helium Ion Induced Reactions in Plutonium Isotopes  

E-Print Network (OSTI)

Nuclear Energy Series, Plutonium Project Record, Vol. 1 4Nuclear Energy S e r i e s , Plutonium P r o j e c t RecordNuclear Energy S e r i e s , Plutonium P r o j e c t Record,

Glass, Richard A.; Carr, Robert J.; Cobble, James W.; Seaborg, Glenn T.

1956-01-01T23:59:59.000Z

125

Isotopes of helium, hydrogen, and carbon as groundwater tracers in aquifers along the Colorado River  

E-Print Network (OSTI)

2.1. Battle for Colorado River Water. Importance ofthat will be replaced by Colorado River water in Arizona,in Aquifers along the Colorado River A Thesis submitted in

Haber, Samuel Ainsworth

2009-01-01T23:59:59.000Z

126

SRS upgrades helium recovery system | National Nuclear Security  

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

upgrades helium recovery system | National Nuclear Security upgrades helium recovery system | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > NNSA Blog > SRS upgrades helium recovery system SRS upgrades helium recovery system Posted By Office of Public Affairs Savannah River Site (SRS) Tritium Programs recently completed a project to design, build and relocate a new system for separating and capturing

127

Shock Experiments on Pre-Compressed Fluid Helium  

Science Conference Proceedings (OSTI)

We summarize current methods and results for coupling laser-induced shocks into pre-compressed Helium contained in a diamond anvil cell (DAC). We are able to load helium, hydrogen, deuterium, and helium-hydrogen mixtures into a DAC and propagate a laser-generated shock into the pre-compressed sample. This technique has allowed us to measure the Hugoniot for helium at initial densities ranging from 1 to 3.5 times liquid density. We have developed and used a methodology whereby all of our measurements are referenced to crystalline quartz, which allows us to update our results as the properties of quartz are refined in the future. We also report the identification and elimination of severe electro-magnetic pulses (EMP) associated with plasma stagnation associated with ablation in a DAC.

Eggert, J. H.; Celliers, P. M.; Hicks, D. G.; Rygg, J. R.; Collins, G. W. [Lawrence Livermore National Laboratory, Livermore CA (United States); Brygoo, S.; Loubeyre, P. [Commissariat a l'Energie Atomique, Bruyeres-le-Chatel (France); McWilliams, R. S.; Spaulding, D.; Jeanloz, R. [University of California, Berkeley, CA (United States); Boehly, T. R. [University of Rochester, Rochester, NY (United States)

2009-09-10T23:59:59.000Z

128

The Liquefaction of Hydrogen and Helium Using Small Coolers  

E-Print Network (OSTI)

because the J-T valve and heat exchanger clogged because ofseparate J-T valve and J-T heat exchanger had to be used. Itadded J-T circuit and heat exchanger, to liquefy helium have

Green, Michael A.

2006-01-01T23:59:59.000Z

129

Helium Pumping Wall for a Liquid Lithium Tokamak Richard Majeski...  

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

is that a permeable wall is used to separate out helium produced as ash by a burning fusion reactor. This would replace the divertor structure and associated pumps in a...

130

Operations aspects of the Fermilab Central Helium Liquefier Facility  

SciTech Connect

The Fermilab Central Helium Liquefier (CHL) facility consists of helium and nitrogen reliquefier plants operated 24 hours-a-day to supply LHe at 4.6{degrees}K and LN{sub 2} for the Fermilab Tevatron superconducting proton-antiproton collider ring and to recover warm return gases. Operating aspects of CHL, including different equipment and systems reliability, availability, maintenance experience, safety concerns, and economics aspects are discussed.

Geynisman, M.G.; Makara, J.N.

1995-03-01T23:59:59.000Z

131

Operations aspects of the Fermilab Central Helium Liquefier facility  

SciTech Connect

The Fermilab Central Helium Liquefier (CHL) facility consists of helium and nitrogen reliquefier plants operated 24 hours-a-day to supply LHe at 4.6 K and LN{sub 2} for the Fermilab Tevatron superconducting proton-antiproton collider ring and to recover warm return gases. Operating aspects of CHL, including different equipment and systems reliability, availability, maintenance experience, safety concerns, and economics aspects are discussed.

Geynisman, M.G.; Makara, J.N.

1996-09-01T23:59:59.000Z

132

Recovery of purified helium or hydrogen from gas mixtures  

DOE Patents (OSTI)

A process is described for the removal of helium or hydrogen from gaseous mixtures also containing contaminants. The gaseous mixture is contacted with a liquid fluorocarbon in an absorption zone maintained at superatomspheric pressure to preferentially absorb the contaminants in the fluorocarbon. Unabsorbed gas enriched in hydrogen or helium is withdrawn from the absorption zone as product. Liquid fluorocarbon enriched in contaminants is withdrawn separately from the absorption zone. (10 claims)

Merriman, J.R.; Pashley, J.H.; Stephenson, M.J.; Dunthorn, D.I.

1974-01-15T23:59:59.000Z

133

Global Energy Perspectives  

U.S. Energy Information Administration (EIA)

Global Energy Perspectives: Supply Security, Economic Development and Sustainability The Annual Energy Policy Conference of the National Capital Area ...

134

Strategic Isotope Production | ornl.gov  

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

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

135

Isotopes as Environmental Tracers in Archived Biological ...  

Science Conference Proceedings (OSTI)

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

2012-10-02T23:59:59.000Z

136

Isotopic Analysis At Nw Basin & Range Region (Kennedy & Van Soest, 2007) |  

Open Energy Info (EERE)

Nw Basin & Range Region (Kennedy & Van Soest, 2007) Nw Basin & Range Region (Kennedy & Van Soest, 2007) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Nw Basin & Range Region (Kennedy & Van Soest, 2007) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced permeability and that mantle fluids can penetrate the ductile lithosphere, even in regions where there is no substantial magmatism. Superimposed on the regional trend are local, high 3He/4He anomalies indicating hidden magmatic activity and/or deep

137

Isotopic Analysis At Northern Basin & Range Region (Kennedy & Van Soest,  

Open Energy Info (EERE)

Northern Basin & Range Region (Kennedy & Van Soest, Northern Basin & Range Region (Kennedy & Van Soest, 2007) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis- Fluid At Northern Basin & Range Region (Kennedy & Van Soest, 2007) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced permeability and that mantle fluids can penetrate the ductile lithosphere, even in regions where there is no substantial magmatism. Superimposed on the regional trend are local, high 3He/4He anomalies indicating hidden magmatic activity and/or deep

138

Isotopic Analysis At Cascades Region (Kennedy & Van Soest, 2007) | Open  

Open Energy Info (EERE)

Analysis At Cascades Region (Kennedy & Van Soest, 2007) Analysis At Cascades Region (Kennedy & Van Soest, 2007) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis-Fluid At Cascades Region (Kennedy & Van Soest, 2007) Exploration Activity Details Location Cascades Geothermal Region Exploration Technique Isotopic Analysis- Fluid Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes The correspondence of helium isotope ratios and active transtensional deformation indicates a deformation-enhanced permeability and that mantle fluids can penetrate the ductile lithosphere, even in regions where there is no substantial magmatism. Superimposed on the regional trend are local, high 3He/4He anomalies indicating hidden magmatic activity and/or deep

139

Separation of sulfur isotopes  

DOE Patents (OSTI)

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

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

1976-06-22T23:59:59.000Z

140

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

Science Conference Proceedings (OSTI)

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

B. Federer; N. Brichet; J. Jouzel

1982-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

David Lee, Douglas Osheroff, Superfluidity, and Helium 3  

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

David Lee, Douglas Osheroff, Superfluidity, and Helium 3 David Lee, Douglas Osheroff, Superfluidity, and Helium 3 Resources with Additional Information David M. Lee and Douglas D. Osheroff received the 1996 Nobel Prize in Physics for 'their discovery of superfluidity in helium-3'. "In 1976, Lee shared with Richardson and Osheroff their earliest recognition for studies of superfluidity, the Simon Memorial Prize of the British Physical Society. The Buckley Prize of the American Physical Society followed for the trio in 1981. ... Douglas D. Osheroff Douglas D. Osheroff Courtesy AIP Emilio Segrè Visual Archives, AIP Meggers Gallery of Nobel Laureates David Lee David M. Lee Photo by Janerik Henriksson, Courtesy AIP Emilio Segrè Visual Archievs, W.F. Meggers Gallery of Nobel Laureate From 1966-67, Lee was a visiting scientist at Brookhaven National Laboratory ... ."1 His research at Cornell University includes " Low Temperature Physics: Normal and superfluid 3He, studies of the orientation of solid helium by optical birefringence, solid 3He and 4He, lambda phase diagram of 3He - 4He mixtures, quasiparticle tunneling in superconductors, magnetic resonance and ultrasound techniques, cooling by adiabatic demagnetization and the Pomeranchuk technique, spin waves in spin polarized hydrogen gas, high concentrations of hydrogen and nitrogen atons via matrix isolation by impurity-helium solids, magnetism, electron spin resonance."2

142

ISOTOPE SEPARATION AND ISOTOPE EXCHANGE. A Bibliography with Abstracts  

SciTech Connect

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

Begun, G.M.

1959-10-28T23:59:59.000Z

143

DEEP WATER ISOTOPIC CURRENT ANALYZER  

DOE Patents (OSTI)

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

Johnston, W.H.

1964-04-21T23:59:59.000Z

144

Method for separating boron isotopes  

SciTech Connect

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

Rockwood, Stephen D. (Los Alamos, NM)

1978-01-01T23:59:59.000Z

145

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

Open Energy Info (EERE)

geothermal energy development. Author(s): B. M. Kennedy, M. C. van Soest Published: Science, 2007 Document Number: Unavailable DOI: Unavailable Isotopic Analysis At Cascades...

146

A liquid helium cryogenic system design for the GEM magnet  

SciTech Connect

The Superconducting Super Collider (SSC) Gammas, Electrons, Muons (GEM) magnet is a large superconducting solenoid with a total mass of 1.05 {times} 10{sup 6} kg and a stored energy of 2.5 G. A cryogenic system to cool and to maintain the GEM magnet to liquid helium temperature is described. The system is designed to operate effectively under a variety of operating conditions, including cooldown/warm-up, steady state operations, and quench. Primary cooling during steady-state operation is based on natural circulation thermosiphon flow through cooling tubes in the solenoid support bobbin. Additional cooling loops are included for lead and joint cooling and conductor stabilization. A helium refrigerator/liquefier rated at 2 kill and 20 g/s will be specified to meet the refrigeration requirements. Cooldown of the magnet from 300 K to liquid nitrogen temperatures is accomplished using a counterflow helium-to-liquid-nitrogen heat exchanger independent of the helium refrigerator. The system incorporates provisions for maintenance access during accelerator beam operation.

Deis, G.; Warren, R.P. [Lawrence Livermore National Lab., CA (United States); Richied, D.E.; Martovetsky, N.N.; Krupczak, J.J.; Sidi-Yekhlef, A.; Pace, J.R.; Collins, C.A. [Superconducting Super Collider Lab., Dallas, TX (United States)

1993-06-01T23:59:59.000Z

147

The Liquefaction of Hydrogen and Helium Using Small Coolers  

DOE Green Energy (OSTI)

This report discusses the history of the liquefaction of hydrogen and helium using small coolers. This history dates form the 1960's when two stage GM coolers capable of reaching 7 K were used to liquefy helium and hydrogen by suing an added compressor and J-T circuit. Liquefaction using the added circuit failed to become mainstream because the J-T valve and heat exchanger clogged because of impurities in the gas being liquefied. Liquefaction using a GM cooler without an added J-T circuit proved to be difficult because the first stage was not used to pre-cool the gas coming to the second stage of the cooler. Once the gas being liquefied was pre-cooled using the cooler first stage, improvements in the liquefaction rates were noted. The advent of low temperature pulse tube cooler (down to 2.5 K) permitted one to achieve dramatic improvement is the liquefactions rates for helium. Similar but less dramatic improvements are expected for hydrogen as well. Using the PT-415 cooler, one can expect liquefaction rates of 15 to 20 liters per day for helium or hydrogen provided the heat leak into the cooler and the storage vessel is low. A hydrogen liquefier for MICE is presented at the end of this report.

Green, Michael A.

2006-02-12T23:59:59.000Z

148

Etching of Graphene Devices with a Helium Ion Beam  

E-Print Network (OSTI)

IM microscope image in Figure 2a, was He ion etched by sequen- tial imaging in high resolution. The grapheneEtching of Graphene Devices with a Helium Ion Beam Max C. Lemme, David C. Bell,,§ James R. Williams as for pos- sible nanoelectronics applications.1 3 Many experiments in the field are targeted at graphene

Lukin, Mikhail

149

Charge Distribution about an Ionizing Electron Track in Liquid Helium  

E-Print Network (OSTI)

The dependence on an applied electric field of the ionization current produced by an energetic electron stopped in liquid helium can be used to determine the spatial distribution of secondary electrons with respect to their geminate partners. An analytic expression relating the current and distribution is derived. The distribution is found to be non-Gaussian with a long tail at larger distances.

G. M. Seidel; T. M. Ito; A. Ghosh; B. Sethumadhavan

2013-10-04T23:59:59.000Z

150

TRANSMISSION ELECTRON MICROSCOPY STUDY OF HELIUM BEARING FUSION WELDS  

DOE Green Energy (OSTI)

A transmission electron microscopy (TEM) study was conducted to characterize the helium bubble distributions in tritium-charged-and-aged 304L and 21Cr-6Ni-9Mn stainless steel fusion welds containing approximately 150 appm helium-3. TEM foils were prepared from C-shaped fracture toughness test specimens containing {delta} ferrite levels ranging from 4 to 33 volume percent. The weld microstructures in the low ferrite welds consisted mostly of austenite and discontinuous, skeletal {delta} ferrite. In welds with higher levels of {delta} ferrite, the ferrite was more continuous and, in some areas of the 33 volume percent sample, was the matrix/majority phase. The helium bubble microstructures observed were similar in all samples. Bubbles were found in the austenite but not in the {delta} ferrite. In the austenite, bubbles had nucleated homogeneously in the grain interiors and heterogeneously on dislocations. Bubbles were not found on any austenite/austenite grain boundaries or at the austenite/{delta} ferrite interphase interfaces. Bubbles were not observed in the {delta} ferrite because of the combined effects of the low solubility and rapid diffusion of tritium through the {delta} ferrite which limited the amount of helium present to form visible bubbles.

Tosten, M; Michael Morgan, M

2008-12-12T23:59:59.000Z

151

PULSATIONS IN HYDROGEN BURNING LOW-MASS HELIUM WHITE DWARFS  

SciTech Connect

Helium core white dwarfs (WDs) with mass M {approx}< 0.20 M {sub sun} undergo several Gyr of stable hydrogen burning as they evolve. We show that in a certain range of WD and hydrogen envelope masses, these WDs may exhibit g-mode pulsations similar to their passively cooling, more massive carbon/oxygen core counterparts, the ZZ Cetis. Our models with stably burning hydrogen envelopes on helium cores yield g-mode periods and period spacings longer than the canonical ZZ Cetis by nearly a factor of 2. We show that core composition and structure can be probed using seismology since the g-mode eigenfunctions predominantly reside in the helium core. Though we have not carried out a fully nonadiabatic stability analysis, the scaling of the thermal time in the convective zone with surface gravity highlights several low-mass helium WDs that should be observed in search of pulsations: NLTT 11748, SDSS J0822+2753, and the companion to PSR J1012+5307. Seismological studies of these He core WDs may prove especially fruitful, as their luminosity is related (via stable hydrogen burning) to the hydrogen envelope mass, which eliminates one model parameter.

Steinfadt, Justin D. R. [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106 (United States); Bildsten, Lars [Kavli Institute for Theoretical Physics and Department of Physics, Kohn Hall, University of California, Santa Barbara, CA 93106 (United States); Arras, Phil, E-mail: jdrs@physics.ucsb.ed, E-mail: bildsten@kitp.ucsb.ed, E-mail: arras@virginia.ed [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States)

2010-07-20T23:59:59.000Z

152

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

153

Preliminary safety evaluation of the Gas Turbine-Modular Helium Reactor (GT-MHR)  

SciTech Connect

A qualitative comparison between the safety characteristics of the Gas Turbine-Modular Helium Reactor (GT-MHR) and those of the steam cycle shows that the two designs achieve equivalent levels of overall safety performance. This comparison is obtained by applying the scaling laws to detailed steam-cycle computations as well as the conclusions obtained from preliminary GT-MHR model simulations. The gas turbine design is predicted to be superior for some event categories, while the steam cycle design is better for others. From a safety perspective, the GT-MHR has a modest advantage for pressurized conduction cooldown events. Recent computational simulations of 102 column, 550 MW(t) GT-MHR during a depressurized conduction cooldown show that peak fuel temperatures are within the limits. The GT-MHR has a significantly lower risk due to water ingress events under operating conditions. Two additional scenarios, namely loss of load event and turbine deblading event that are specific to the GT-MHR design are discussed. Preliminary evaluation of the GT-MHR`s safety characteristics indicate that the GT-MHR can be expected to satisfy or exceed its safety requirements.

Dunn, T.D.; Lommers, L.J.; Tangirala, V.E.

1994-04-01T23:59:59.000Z

154

Theoretical Perspective of Charm Physics  

E-Print Network (OSTI)

A perspective on charm physics, emphasizing recent developments, future prospects, and the interplay with lattice QCD.

Kronfeld, Andreas S

2013-01-01T23:59:59.000Z

155

Cold Vacuum Drying (CVD) Facility General Service Helium System Design Description  

DOE Green Energy (OSTI)

The purpose of this System Design Description (SDD) is to describe the characteristics of the Cold Vacuum Drying (CVD) Facility general service helium system. The general service helium system is a general service facility process support system, but does include safety-class structures, systems and components (SSCs) providing protection to the offsite public. The general service helium system also performs safety-significant functions that provide protection to onsite workers. The general helium system essential function is to provide helium (He) to support process functions during all phases of facility operations. General service helium is used to purge the cask and the MCO in order to maintain their internal atmospheres below hydrogen flammability concentrations. The general service helium system also supplies helium to purge the process water conditioning (PWC) lines and components and the vacuum purge system (VPS) vacuum pump. The general service helium system, if available following an Safety Class Instrument and Control System (SCIC) Isolation and Purge (IS0 and PURGE) Trip, can provide an alternate general service helium system source to supply the Safety-Class Helium (SCHe) System.

SHAPLEY, B.J.

2000-04-20T23:59:59.000Z

156

Isotopically labeled compositions and method  

DOE Patents (OSTI)

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

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

2011-07-12T23:59:59.000Z

157

Pulsed extraction of ionization from helium buffer gas  

E-Print Network (OSTI)

The migration of intense ionization created in helium buffer gas under the influence of applied electric fields is considered. First the chemical evolution of the ionization created by fast heavy-ion beams is described. Straight forward estimates of the lifetimes for charge exchange indicate a clear suppression of charge exchange during ion migration in low pressure helium. Then self-consistent calculations of the migration of the ions in the electric field of a gas-filled cell at the National Superconducting Cyclotron Laboratory (NSCL) using a Particle-In-Cell computer code are presented. The results of the calculations are compared to measurements of the extracted ion current caused by beam pulses injected into the NSCL gas cell.

D. J. Morrissey; G. Bollen; M. Facina; S. Schwarz

2008-08-13T23:59:59.000Z

158

Satellite spectra for helium-like titanium. Part II  

Science Conference Proceedings (OSTI)

K/sup ..cap alpha../ x-ray spectra of helium-like titanium, Ti XXI, from Tokamak Fusion Test Reactor (TFTR) plasmas have been observed with a high resolution crystal spectrometer and have been used as a diagnostic of central plasma parameters. The data allow detailed comparison with recent theoretical predictions for the Ti XXI helium-like lines and the associated satellite spectrum in the wavelength range from 2.6000 to 2.6400 A. Improved values for the excitation rate coefficients of the Ti XXI resonance line, the intercombination lines and the forbidden line, and new theoretical results on the wavelengths and transition probabilities for beryllium-like satellites due to transitions of the type 1s/sup 2/ 2lnl' - 1s2p2l'' nl'' with n = 2-4 have been calculated.

Bitter, M.; Hill, K.W.; Zarnstorff, M.; von Goeler, S.; Hulse, R.; Johnson, L.C.; Sauthoff, N.R.; Sesnic, S.; Young, K.M.; Tavernier, M.

1985-08-01T23:59:59.000Z

159

Metastable Helium Molecules as Tracers in Superfluid {sup 4}He  

SciTech Connect

Metastable helium molecules generated in a discharge near a sharp tungsten tip immersed in superfluid {sup 4}He are imaged using a laser-induced-fluorescence technique. By pulsing the tip, a small cloud of He{sub 2}* molecules is produced. We can determine the normal-fluid velocity in a heat-induced counterflow by tracing the position of a single molecule cloud. As we run the tip in continuous field-emission mode, a normal-fluid jet from the tip is generated and molecules are entrained in the jet. A focused 910 nm pump laser pulse is used to drive a small group of molecules to the first excited vibrational level of the triplet ground state. Subsequent imaging of the tagged molecules with an expanded 925 nm probe laser pulse allows us to measure the flow velocity of the jet. The techniques we developed provide new tools in quantitatively studying the normal fluid flow in superfluid helium.

Guo, W.; Wright, J. D.; Cahn, S. B.; Nikkel, J. A.; McKinsey, D. N. [Physics Department, Yale University, New Haven, Connecticut 06515 (United States)

2009-06-12T23:59:59.000Z

160

Helium-ion-induced release of hydrogen from graphite  

DOE Green Energy (OSTI)

The ion-induced release of hydrogen from AXF-5Q graphite was studied for 350-eV helium ions. The hydrogen was implanted into the graphite with a low energy (approx.200 eV) and to a high fluence. This achieved a thin (approx.10-nm), saturated near-surface region. The release of hydrogen was measured as a function of helium fluence. A model that includes ion-induced detrapping, retrapping, and surface recombination was used to analyze the experimental data. A value of (1.65 +- 0.2) x 10/sup -16/ cm/sup 2/ was obtained from the detrapping cross section, and a value of (0.5 to 4) x 10/sup -14/ cm/sup 4//atoms was obtained for the recombination coefficient. 11 refs., 4 figs.

Langley, R.A.

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

Shock Wave Structure for Argon, Helium, and Nitrogen  

E-Print Network (OSTI)

We compare the thickness of shock wave fronts at different Mach numbers, modeled via Navier-Stokes (NS) and Quasi-gasdynamic (QGD) equations, with experimental results from the literature. Monoatomic argon and helium, and diatomic nitrogen, are considered. In this modeling a finite-difference scheme with second-order spatial accuracy is employed. For argon the density thickness calculated via QGD and NS models are in good agreement with each other, and with the experimental results. For helium QGD and NS results agree well with those from the bimodal model. For nitrogen, the QGD results are closer to the experimental data than NS results. The QGD-based algorithm converges to the steady state solution faster than the NS-based one.

T. G. Elizarova; I. A. Shirokov; S. Montero

2004-07-28T23:59:59.000Z

162

A High Reliability Gas-driven Helium Cryogenic Centrifugal Compressor  

E-Print Network (OSTI)

A helium cryogenic compressor was developed and tested in real conditions in 1996. The achieved objective was to compress 0.018 kg/s Helium at 4 K @ 1000 Pa (10 mbar) up to 3000 Pa (30 mbar). This project was an opportunity to develop and test an interesting new concept in view of future needs. The main features of this new specific technology are described. Particular attention is paid to the gas bearing supported rotor and to the pneumatic driver. Trade off between existing technologies and the present work are presented with special stress on the bearing system and the driver. The advantages are discussed, essentially focused on life time and high reliability without maintenance as well as non pollution characteristic. Practical operational modes are also described together with the experimental performances of the compressor. The article concludes with a brief outlook of future work.

Bonneton, M; Gistau-Baguer, Guy M; Turcat, F; Viennot, P

1998-01-01T23:59:59.000Z

163

Stimulated Brillouin Scattering from Helium-Hydrogen Plasmas  

DOE Green Energy (OSTI)

An extensive study of the stimulated Brillouin scattering (SBS) in helium-hydrogen plasmas has been performed using a gas jet at the Janus Laser Facility. We observe three regions of reflectivity by varying the probe intensity from 10{sup 14} to 10{sup 16}: saturated region, linear region, and near SBS threshold region. In the linear regime, adding small amounts of H to a He plasma reduces the SBS reflectivity by a factor of 4.

Froula, D H; Divol, L; Price, D; Gregori, G; Williams, E A; Glenzer, S H

2003-08-22T23:59:59.000Z

164

Open Questions in Stellar Helium Burning Addressed With Real Photons  

E-Print Network (OSTI)

The outcome of helium burning is the formation of the two elements, carbon and oxygen. The ratio of carbon to oxygen at the end of helium burning is crucial for understanding the final fate of a progenitor star and the nucleosynthesis of heavy elements in Type II supernova, with oxygen rich star predicted to collapse to a black hole, and a carbon rich star to a neutron star. Type Ia supernovae (SNeIa) are used as standard candles for measuring cosmological distances with the use of an empirical light curve-luminosity stretching factor. It is essential to understand helium burning that yields the carbon/oxygen white dwarf and thus the initial stage of SNeIa. Since the triple alpha-particle capture reaction, $^{8}Be(\\alpha,\\gamma)^{12}C$, the first burning stage in helium burning, is well understood, one must extract the cross section of the $^{12}C(\\alpha,\\gamma)^{16}O$ reaction at the Gamow window (300 keV) with high accuracy of approximately 10% or better. This goal has not been achieved despite repeated strong statements that appeared in the literature. In particular constraint from the beta-delayed alpha-particle emission of $^{16}N$ were shown to not sufficiently restrict the p-wave cross section factor; e.g. a low value of $S_{E1}(300)$ can not be ruled out. Measurements at low energies, are thus mandatory for determining the elusive cross section factor for the $^{12}C(\\alpha,\\gamma)^{16}O$ reaction. We are constructing a Time Projection Chamber (TPC) for use with high intensity photon beams extracted from the HI$\\gamma$S/TUNL facility at Duke University to study the $^{16}O(\\gamma,\\alpha)^{12}C$ reaction, and thus the direct reaction at energies as low as 0.7 MeV. This work is in progress.

Moshe Gai

2003-03-20T23:59:59.000Z

165

Semiclassical description of antiproton capture on atomic helium  

SciTech Connect

A semiclassical, many-body atomic model incorporating a momentum-dependent Heisenberg core to stabilize atomic electrons is used to study antiproton capture on helium. Details of the antiproton collisions leading to eventual capture are presented, including the energy and angular-momentum states of incident antiprotons which result in capture via single- or double-electron ionization, i.e., into He[sup 2+][ital [bar p

Beck, W.A. (Department of Physics, University of Washington, Seattle, Washington 98195 (United States) Quantum Medical Systems, Issaquah, Washington 98027 (United States)); Wilets, L. (Department of Physics, University of Washington, Seattle, Washington 98195 (United States)); Alberg, M.A. (Department of Physics, University of Washington, Seattle, Washington 98195 (United States) Department of Physics, Seattle University, Seattle, Washington 98122 (United States))

1993-10-01T23:59:59.000Z

166

ISOTOPE FRACTIONATION PROCESS  

DOE Patents (OSTI)

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

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

1958-05-20T23:59:59.000Z

167

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

168

Mathematical modeling of a Fermilab helium liquefier coldbox  

SciTech Connect

Fermilab Central Helium Liquefier (CHL) facility is operated 24 hours-a-day to supply 4.6{degrees}K for the Fermilab Tevatron superconducting proton-antiproton collider Ring and to recover warm return gases. The centerpieces of the CHL are two independent cold boxes rated at 4000 and 5400 liters/hour with LN{sub 2} precool. These coldboxes are Claude cycle and have identical heat exchangers trains, but different turbo-expanders. The Tevatron cryogenics demand for higher helium supply from CHL was the driving force to investigate an installation of an expansion engine in place of the Joule-Thompson valve. A mathematical model was developed to describe the thermo- and gas-dynamic processes for the equipment included in the helium coldbox. The model is based on a finite element approach, opposite to a global variables approach, thus providing for higher accuracy and conversion stability. Though the coefficients used in thermo- and gas-dynamic equations are unique for a given coldbox, the general approach, the equations, the methods of computations, and most of the subroutines written in FORTRAN can be readily applied to different coldboxes. The simulation results are compared against actual operating data to demonstrate applicability of the model.

Geynisman, M.G.; Walker, R.J.

1995-12-01T23:59:59.000Z

169

UCN production by multiphonon processes in superfluid Helium under pressure  

E-Print Network (OSTI)

Cold neutrons are converted to ultra-cold neutrons (UCN) by the excitation of a single phonon or multiphonons in superfluid helium. The dynamic scattering function S(q, omega) of the superfluid helium strongly depends on pressure, leading to a pressure- dependent differential UCN production rate. A phenomenological expression for the multiphonon part of the scattering function s(lambda) describing UCN production has been derived from inelastic neutron scattering data. When combined with the production rate from single phonon processes this allows us to calculate the UCN production for any incident neutron flux. For calculations of the UCN production from single phonon processes we propose to use the values for S*(SVP) = 0.118(8) and S*(20 bar) = 0.066(6). As an example we will calculate the expected UCN production rate at the cold neutron beam for fundamental physics PF1b at the Institut Laue Langevin. We conclude that UCN production in superfluid helium under pressure is not attractive.

P. Schmidt-Wellenburg; K. H. Andersen; O. Zimmer

2008-11-26T23:59:59.000Z

170

On the Evolution of Helium in Blue Compact Galaxies  

E-Print Network (OSTI)

We discuss the chemical evolution of dwarf irregular and blue compact galaxies in light of recent data, new stellar yields and chemical evolution models. We examine the abundance data for evidence of HII region self-enrichment effects, which would lead to correlations in the scatter of helium, nitrogen, and oxygen abundances around their mean trends. The observed helium abundance trends show no such correlations, though the nitrogen--oxygen trend does show strong evidence for real scatter beyond observational error. We construct simple models for the chemical evolution of these galaxies, using the most recent yields of \\he4, C, N and O in intermediate- and high-mass stars. The effects of galactic outflows, which can arise both from bulk heating and evaporation of the ISM, and from the partial escape of enriched supernova ejecta are included. In agreement with other studies, we find that supernova-enriched outflows can roughly reproduce the observed He, C, N, and O trends; however, in models that fit N versus O, the slopes $\\Delta Y/\\Delta$O and $\\Delta Y/\\Delta$N consistently fall more than $2\\sigma$ below the fit to observations. We discuss the role of the models and their uncertainties in the extrapolation of primordial helium from the data. We also explore the model dependence arising nucleosynthesis uncertainties associated with nitrogen yields in intermediate mass stars, the fate of $8-11 \\msol$ stars, and massive star winds.

Brian D. Fields; Keith A. Olive

1998-03-25T23:59:59.000Z

171

Helium-Based Soundwave Chiller: Trillium: A Helium-Based Sonic Chiller- Tons of Freezing with 0 GWP Refrigerants  

SciTech Connect

BEETIT Project: Penn State is designing a freezer that substitutes the use of sound waves and environmentally benign refrigerant for synthetic refrigerants found in conventional freezers. Called a thermoacoustic chiller, the technology is based on the fact that the pressure oscillations in a sound wave result in temperature changes. Areas of higher pressure raise temperatures and areas of low pressure decrease temperatures. By carefully arranging a series of heat exchangers in a sound field, the chiller is able to isolate the hot and cold regions of the sound waves. Penn State’s chiller uses helium gas to replace synthetic refrigerants. Because helium does not burn, explode or combine with other chemicals, it is an environmentally-friendly alternative to other polluting refrigerants. Penn State is working to apply this technology on a large scale.

None

2010-09-01T23:59:59.000Z

172

Method of separating boron isotopes  

SciTech Connect

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

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

1984-01-01T23:59:59.000Z

173

Isotopic Analysis- Fluid | Open Energy Information  

Open Energy Info (EERE)

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

174

It's Elemental - Isotopes of the Element Neptunium  

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

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

175

It's Elemental - Isotopes of the Element Sulfur  

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

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

176

It's Elemental - Isotopes of the Element Argon  

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

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

177

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

178

It's Elemental - Isotopes of the Element Ruthenium  

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

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

179

It's Elemental - Isotopes of the Element Molybdenum  

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

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

180

It's Elemental - Isotopes of the Element Thorium  

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

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

Note: This page contains sample records for the topic "helium isotope perspective" 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

It's Elemental - Isotopes of the Element Protactinium  

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

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

182

High-Precision Isotopic Reference Materials  

Science Conference Proceedings (OSTI)

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

2012-10-22T23:59:59.000Z

183

Production of carbon monoxide-free hydrogen and helium from a high-purity source  

DOE Patents (OSTI)

The invention provides vacuum swing adsorption processes that produce an essentially carbon monoxide-free hydrogen or helium gas stream from, respectively, a high-purity (e.g., pipeline grade) hydrogen or helium gas stream using one or two adsorber beds. By using physical adsorbents with high heats of nitrogen adsorption, intermediate heats of carbon monoxide adsorption, and low heats of hydrogen and helium adsorption, and by using vacuum purging and high feed stream pressures (e.g., pressures of as high as around 1,000 bar), pipeline grade hydrogen or helium can purified to produce essentially carbon monoxide -free hydrogen and helium, or carbon monoxide, nitrogen, and methane-free hydrogen and helium.

Golden, Timothy Christopher (Allentown, PA); Farris, Thomas Stephen (Bethlehem, PA)

2008-11-18T23:59:59.000Z

184

Helium Recovery in the LHC Cryogenic System following Magnet Resistive Transitions  

E-Print Network (OSTI)

A resistive transition (quench) of the Large Hadron Collider magnets provokes the expulsion of helium from the magnet cryostats to the helium recovery system. A high-volume, vacuum-insulated recovery line connected to several uninsulated medium-pressure gas storage tanks, forms the main constituents of the system. Besides a dedicated hardware configuration, helium recovery also implies specific procedures that should follow a quench, in order to conserve the discharged helium and possibly make use of its refrigeration capability. The amount of energy transferred after a quench from the magnets to the helium leaving the cold mass has been estimated on the basis of experimental data. Based on these data, the helium thermodynamic state in the recovery system is calculated using a lumped parameter approach. The LHC magnet quenches are classified ina parametric way from their cryogenic consequences and procedures that should follow the quench are proposed.

Chorowski, M; Serio, L; Tavian, L; Wagner, U; Van Weelderen, R

1998-01-01T23:59:59.000Z

185

Meteorological Data Fields “In Perspective  

Science Conference Proceedings (OSTI)

Perspective display techniques can be applied to meteorological data sets to aid in their interpretation. Examples of a perspective display procedure applied to satellite and aircraft visible and infrared image pairs and to stereo cloud-top ...

A. F. Hasler; H. Pierce; K. R. Morris; J. Dodge

1985-07-01T23:59:59.000Z

186

Cold Vacuum Drying (CVD) Facility General Service Helium System Design Description  

DOE Green Energy (OSTI)

This document describes the Cold Vacuum Drying Facility general service helium system (GSHe). The GSHe is a general service facility process support system, but does include safety-class systems, structures and components providing protection to the offsite public. The GSHe also performs safety-significant functions that provide protection to onsite workers. The GSHe essential function is to provide helium to support process functions during all phases of facility operations. GSHe helium is used to purge the cask and the MCO in order to maintain their internal atmospheres below hydrogen flammability concentrations. The GSHe also supplies helium to purge the PWC lines and components and the VPS vacuum pump.

FARWICK, C.C.

1999-07-06T23:59:59.000Z

187

Interim Report on the Optimization and Feasibility Studies for the Neutron Detection without Helium-3 Project  

SciTech Connect

This report provides the status and results of the first year's effort in modeling and simulation to investigate alternatives to helium-3 for neutron detection in safeguards applications.

Ely, James H.

2012-03-19T23:59:59.000Z

188

EPRI NMAC Maintainability Review of the International Gas-Turbine Modular Helium Reactor Power Conversion Unit  

Science Conference Proceedings (OSTI)

This report provides information of interest to the designers of modular helium-reactor-driven gas turbines and persons considering the purchase of this type of plant.

2001-02-01T23:59:59.000Z

189

Ultra high vacuum pumping system and high sensitivity helium leak detector  

DOE Patents (OSTI)

An improved helium leak detection method and apparatus are disclosed which increase the leak detection sensitivity to 10{sup {minus}13} atm cc/s. The leak detection sensitivity is improved over conventional leak detectors by completely eliminating the use of o-rings, equipping the system with oil-free pumping systems, and by introducing measured flows of nitrogen at the entrances of both the turbo pump and backing pump to keep the system free of helium background. The addition of dry nitrogen flows to the system reduces back streaming of atmospheric helium through the pumping system as a result of the limited compression ratios of the pumps for helium. 2 figs.

Myneni, G.R.

1997-12-30T23:59:59.000Z

190

Ultra high vacuum pumping system and high sensitivity helium leak detector  

DOE Patents (OSTI)

An improved helium leak detection method and apparatus are disclosed which increase the leak detection sensitivity to 10.sup.-13 atm cc s.sup.-1. The leak detection sensitivity is improved over conventional leak detectors by completely eliminating the use of o-rings, equipping the system with oil-free pumping systems, and by introducing measured flows of nitrogen at the entrances of both the turbo pump and backing pump to keep the system free of helium background. The addition of dry nitrogen flows to the system reduces backstreaming of atmospheric helium through the pumping system as a result of the limited compression ratios of the pumps for helium.

Myneni, Ganapati Rao (Yorktown, VA)

1997-01-01T23:59:59.000Z

191

THE CONSTRUCTION AND TESTING OF A DOUBLE ACTING BELLOWS LIQUID HELIUM PUMP  

E-Print Network (OSTI)

Helium Pump (Without Heat Exchanger S Control Dewar) (LIQUIDcavities from the exit heat exchanger. Both of these valvescopper tube split flow heat exchanger which shares a common

Burns, W.A.

2010-01-01T23:59:59.000Z

192

Compelling Research Opportunities using Isotopes  

SciTech Connect

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

None

2009-04-23T23:59:59.000Z

193

A pencil beam algorithm for helium ion beam therapy  

Science Conference Proceedings (OSTI)

Purpose: To develop a flexible pencil beam algorithm for helium ion beam therapy. Dose distributions were calculated using the newly developed pencil beam algorithm and validated using Monte Carlo (MC) methods. Methods: The algorithm was based on the established theory of fluence weighted elemental pencil beam (PB) kernels. Using a new real-time splitting approach, a minimization routine selects the optimal shape for each sub-beam. Dose depositions along the beam path were determined using a look-up table (LUT). Data for LUT generation were derived from MC simulations in water using GATE 6.1. For materials other than water, dose depositions were calculated by the algorithm using water-equivalent depth scaling. Lateral beam spreading caused by multiple scattering has been accounted for by implementing a non-local scattering formula developed by Gottschalk. A new nuclear correction was modelled using a Voigt function and implemented by a LUT approach. Validation simulations have been performed using a phantom filled with homogeneous materials or heterogeneous slabs of up to 3 cm. The beams were incident perpendicular to the phantoms surface with initial particle energies ranging from 50 to 250 MeV/A with a total number of 10{sup 7} ions per beam. For comparison a special evaluation software was developed calculating the gamma indices for dose distributions. Results: In homogeneous phantoms, maximum range deviations between PB and MC of less than 1.1% and differences in the width of the distal energy falloff of the Bragg-Peak from 80% to 20% of less than 0.1 mm were found. Heterogeneous phantoms using layered slabs satisfied a {gamma}-index criterion of 2%/2mm of the local value except for some single voxels. For more complex phantoms using laterally arranged bone-air slabs, the {gamma}-index criterion was exceeded in some areas giving a maximum {gamma}-index of 1.75 and 4.9% of the voxels showed {gamma}-index values larger than one. The calculation precision of the presented algorithm was considered to be sufficient for clinical practice. Although only data for helium beams was presented, the performance of the pencil beam algorithm for proton beams was comparable. Conclusions: The pencil beam algorithm developed for helium ions presents a suitable tool for dose calculations. Its calculation speed was evaluated to be similar to other published pencil beam algorithms. The flexible design allows easy customization of measured depth-dose distributions and use of varying beam profiles, thus making it a promising candidate for integration into future treatment planning systems. Current work in progress deals with RBE effects of helium ions to complete the model.

Fuchs, Hermann; Stroebele, Julia; Schreiner, Thomas; Hirtl, Albert; Georg, Dietmar [Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria); PEG MedAustron, 2700 Wiener Neustadt (Austria); Department of Nuclear Medicine, Medical University of Vienna, 1090 Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria)

2012-11-15T23:59:59.000Z

194

Isotopic Analysis- Rock | Open Energy Information  

Open Energy Info (EERE)

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

195

Gas Diffusion in Metals: Fundamental Study of Helium-Point Defect Interactions in Iron and Kinetics of Hydrogen Desorption from Zirconium Hydride  

E-Print Network (OSTI)

Gas Diffusion in Metals: Fundamental Study of Helium-PointGas Diffusion in Metals: Fundamental Study of Helium-Point138 8.1.1 Fundamental study of helium-point defect

Hu, Xunxiang

2013-01-01T23:59:59.000Z

196

Studies in Photosynthesis with Isotopes  

E-Print Network (OSTI)

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

Calvin, M.; Bassham, J.A.

1952-01-01T23:59:59.000Z

197

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

198

SUSTAINABILITY New Perspectives  

E-Print Network (OSTI)

societies, but also contribute to creating a truly sustainable future. The specific areas of analysis include population dynamics, sustenance, energy, and pollution. The perspectives and roles and long-term sustainability need to be reconciled through market and regulatory mechanisms that reduce

Edwards, Paul N.

199

Isotope separation apparatus and method  

DOE Patents (OSTI)

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

Feldman, Barry J. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

200

Helium-Cooled Refractory Alloys First Wall and Blanket Evaluation  

Science Conference Proceedings (OSTI)

Under the APEX program the He-cooled system design task is to evaluate and recommend high power density refractory alloy first wall and blanket designs and to recommend and initiate tests to address critical issues. We completed the preliminary design of a helium-cooled, W-5Re alloy, lithium breeder design and the results are reported in this paper. Many areas of the design were assessed, including material selection, helium impurity control, and mechanical, nuclear and thermal hydraulics design, and waste disposal, tritium and safety design. System study results show that at a closed cycle gas turbine (CCGT) gross thermal efficiency of 57.5%, a superconducting coil tokamak reactor, with an aspect ratio of 4, and an output power of 2 GWe, can be projected to have a cost of electricity at 54.6 mill/kWh. Critical issues were identified and we plan to continue the design on some of the critical issues during the next phase of the APEX design study.

Wong, C.P.C.; Nygren, R.E.; Baxi, C.B.; Fogarty, P.; Ghoniem, N.; Khater, H.; McCarthy, K.; Merrill, B.; Nelson, B.; Reis, E.E.; Sharafat, S.; Schleicher, R.; Sze, D.K.; Ulrickson, M.; Willms, S.; Youssef, M.; Zinkel, S.

1999-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

THERMAL PERFORMANCE OF A DUAL-CHANNEL, HELIUM-COOLED, TUNGSTEN HEAT EXCHANGER  

E-Print Network (OSTI)

THERMAL PERFORMANCE OF A DUAL-CHANNEL, HELIUM-COOLED, TUNGSTEN HEAT EXCHANGER Dennis L. Youchison-cooled, refractory heat exchangers are now under consideration for first wall and divertor applications-channel, helium-cooled heat exchanger made almost entirely of tungsten was designed and fabricated by Thermacore

California at Los Angeles, University of

202

The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle  

E-Print Network (OSTI)

The Solar Wind Helium Abundance: Variation with Wind Speed and the Solar Cycle Matthias R. Aellig Alamos National Lab., Los Alamos, NM 87545 Abstract We investigate the helium abundance in the solar wind of 1994 and early 2000 are analyzed. In agreement with similar work for previous solar cycles, we find

Richardson, John

203

Gas Diffusion in Metals: Fundamental Study of Helium-Point Defect Interactions in Iron and Kinetics of Hydrogen Desorption from Zirconium Hydride  

E-Print Network (OSTI)

Ullmaier. Helium and hydrogen effects on the embrittlementT. Troev. The effect of hydrogen and helium on microvoidp. 1-51. M. Steinbruck. Hydrogen absorption by zirconium

Hu, Xunxiang

2013-01-01T23:59:59.000Z

204

Isotope production facility produces cancer-fighting actinium  

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

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

205

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

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

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

206

Unique method for liquid nitrogen precooling of a plate fin heat exchanger in a helium refrigeration cycle  

E-Print Network (OSTI)

Unique method for liquid nitrogen precooling of a plate fin heat exchanger in a helium refrigeration cycle

Weber, T B; Howell, G; Racine, M; Weisend, J G

2004-01-01T23:59:59.000Z

207

Definition: Isotopic Analysis- Fluid | Open Energy Information  

Open Energy Info (EERE)

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

208

Definition: Isotopic Analysis | Open Energy Information  

Open Energy Info (EERE)

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

209

Regional and Local Trends in helium isotopes, basin and range province, western North America: Evidence for deep permeable pathways  

E-Print Network (OSTI)

Temperatures in the Dixie Valley, Nevada, geothermal system.Regional geophysics of the Dixie Valley area: example of aand rocks from the Dixie Valley region, Nevada (1996-1999),

Kennedy, B. Mack; van Soest, Matthijs C.

2005-01-01T23:59:59.000Z

210

Gas Turbine Manufacturers Perspective  

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

Viability and Experience of IGCC From a Viability and Experience of IGCC From a Gas Turbine Manufacturers Perspective ASME - IGCC ASME - IGCC Turbo Turbo Expo Expo June 2001 June 2001 GE Power Systems g Klaus Brun, Ph.D. - Manager Process Power Plant Product & Market Development Robert M. Jones - Project Development Manager Process Power Plants Power Systems Power Systems General Electric Company General Electric Company ABSTRACT GE Power Systems g Economic Viability and Experience of IGCC From a Gas Turbine Manufacturers Perspective High natural gas fuel gas prices combined with new technology developments have made IGCC a competitive option when compared to conventional combined cycle or coal steam turbine cycles. Although the initial investment costs for an IGCC plant are still comparatively high, the low

211

Isotope separation apparatus and method  

DOE Patents (OSTI)

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

Cotter, Theodore P. (Los Alamos, NM)

1982-12-28T23:59:59.000Z

212

Pion Electroproduction form Helium 3, Deuterium, and Hydrogen  

DOE Green Energy (OSTI)

A series of measurements for pion electroproduction from helium-3, deuterium, and hydrogen were completed at the Thomas Jefferson National Accelerator Facility by the NucPi Collaboration. E91003 began taking data in February 1998 and was completed in April 1998. The longitudinal and transverse parts of the differential cross section were extracted, by means of a Rosenbluth type separation, in the direction parallel to the virtual photon, at Q 2 = 0.4 GeV 2 , for W = 1.15 and W = 1.6 GeV. The mass dependence of the longitudinal cross section should provide insight into the surprising apparent absence of any significant cross section enhancement due to excess pions in the nuclear medium.

S. Avery

2002-05-01T23:59:59.000Z

213

Ionization of hydrogen and ionized helium by slow antiprotons  

E-Print Network (OSTI)

We study the ionization process involving antiproton and hydrogen in the energy range between 0.1 keV to 500 keV, using single center close coupling approximation. We construct the scattering wave function using B-spline bases. The results obtained for ionization of atomic hydrogen are compared with other existing theoretical calculations as well as with the available experimental data. The present results are found to be encouraging. We also employed this method to study the ionization of ionized helium in the energy range between 1 and 500 keV. On comparision, the present results are found to interpret well the cross section values calculated using other theories.

Sahoo, S; Walters, H R J

2004-01-01T23:59:59.000Z

214

Nuclear fusion in muonic deuterium-helium complex  

E-Print Network (OSTI)

Experimental study of the nuclear fusion reaction in charge-asymmetrical d-mu-3He complex is presented. The 14.6 MeV protons were detected by three pairs of Si(dE-E) telescopes placed around the cryogenic target filled with the deuterium + helium-3 gas at 34 K. The 6.85 keV gamma rays emitted during the de-excitation of d-mu-3He complex were detected by a germanium detector. The measurements were performed at two target densities, 0.0585 and 0.169 (relative to liquid hydrogen density) with an atomic concentration of 3He c=0.0469. The values of the effective rate of nuclear fusion in d-mu-3He was obtained for the first time, and the J=0 nuclear fusion rate in d-mu-3He was derived.

V. M. Bystritsky; M. Filipowicz; V. V. Gerasimov; P. E. Knowles; F. Mulhauser; N. P. Popov; V. A. Stolupin; V. P. Volnykh; J. Wozniak

2005-06-22T23:59:59.000Z

215

Superconducting cable cooling system by helium gas at two pressures  

DOE Patents (OSTI)

Thermally contacting, oppositely streaming, cryogenic fluid streams in the same enclosure in a closed cycle that changes the fluid from a cool high pressure helium gas to a cooler reduced pressure helium gas in an expander so as to be at different temperature ranges and pressures respectively in go and return legs that are in thermal contact with each other and in thermal contact with a longitudinally extending superconducting transmission line enclosed in the same cable enclosure that insulates the line from the ambient at a temperature T.sub.1. By first circulating the fluid from a refrigerator at one end of the line as a cool gas at a temperature range T.sub.2 to T.sub.3 in the go leg, then circulating the gas through an expander at the other end of the line where the gas becomes a cooler gas at a reduced pressure and at a reduced temperature T.sub.4 and finally by circulating the cooler gas back again to the refrigerator in a return leg at a temperature range T.sub.4 to T.sub.5, while in thermal contact with the gas in the go leg, and in the same enclosure therewith for compression into a higher pressure gas at T.sub.2 in a closed cycle, where T.sub.2 >T.sub.3 and T.sub.5 >T.sub.4, the fluid leaves the enclosure in the go leg as a gas at its coldest point in the go leg, and the temperature distribution is such that the line temperature decreases along its length from the refrigerator due to the cooling from the gas in the return leg.

Dean, John W. (Los Alamos, NM)

1977-01-01T23:59:59.000Z

216

Renewable Hydrogen: The Environmental Perspective  

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

The Environmental Perspective Tyson Eckerle Energy Independence Now Delivering Renewable Hydrogen Workshop November 16 th , 2009. Energy Independence Now Why are we here?...

217

AVLIS enrichment of medical isotopes  

SciTech Connect

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

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

1996-12-31T23:59:59.000Z

218

It's Elemental - Isotopes of the Element Mendelevium  

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

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

219

It's Elemental - Isotopes of the Element Uranium  

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

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

220

It's Elemental - Isotopes of the Element Lithium  

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

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

Note: This page contains sample records for the topic "helium isotope perspective" 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

Isotope GeoloGy1 Unlike physics or chemistry, teaching isotope  

E-Print Network (OSTI)

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

Lee, Cin-Ty Aeolus

222

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

E-Print Network (OSTI)

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

Zeebe, Richard E.

223

Forced flow supercritical helium in a closed heat transfer loop subjected to pulsed heat loads  

Science Conference Proceedings (OSTI)

The superconducting magnets of the tokamak JT-60SA are cooled by means of forced flows of supercritical helium at 4.4 K and 0.5 MPa. The closed loops transfer heat from the magnets to the refrigerator through heat exchangers immersed into a saturated liquid helium bath. An experimental loop was designed to represent a 1/20 scaled down mock-up of JT-60SA central solenoid cooling circuits. This design for keeping the same transit times in the helium circuits

2012-01-01T23:59:59.000Z

224

Apparatus to measure liquid helium boil-off from low-loss superconducting current leads  

DOE Green Energy (OSTI)

A low-loss liquid helium dewar was constructed to measure the liquid helium boil-off rate from high-temperature superconducting current leads. The dewar has a measured background heat leakage rate of 12 mW. Equations calculating the heat leakage rate from the measured vapor mass flow rate in liquid helium boil-off experiments are derived. Parameters that affect the experiments, such as density ratio, absolute pressure, and rate of pressure variation, are discussed. This study is important as superconducting current leads may be used in superconducting magnetic energy storage systems.

Cha, Y.S.; Niemann, R.C.; Hull, J.R. [Argonne National Lab., IL (United States). Energy Technology Div.

1995-06-01T23:59:59.000Z

225

Effects of helium content of microstructural development in Type 316 stainless steel under neutron irradiation  

Science Conference Proceedings (OSTI)

This work investigated the sensitivity of microstructural evolution, particularly precipitate development, to increased helium content during thermal aging and during neutron irradiation. Helium (110 at. ppM) was cold preinjected into solution annealed (SA) DO-heat type 316 stainess steel (316) via cyclotron irradiation. These specimens were then exposed side by side with uninjected samples. Continuous helium generation was increased considerably relative to EBR-II irradiation by irradiation in HFIR. Data were obtained from quantitative analytical electron microscopy (AEM) in thin foils and on extraction replicas. 480 refs., 86 figs., 19 tabs.

Maziasz, P.J.

1985-11-01T23:59:59.000Z

226

Isotope Development & Production | Nuclear Science | ORNL  

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

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

227

Isotopic Abundance in Atom Trap Trace Analysis  

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

228

Indoor Thermal Comfort, an Evolutionary Biology Perspective  

E-Print Network (OSTI)

Comfort, an Evolutionary Biology Perspective John L. StoopsComfort, Evolutionary Biology, Thermo Regulation, ThermalFrom an evolutionary biology perspective, the physiological

Stoops, John L.

2006-01-01T23:59:59.000Z

229

Tracking Clean Energy Progress Energy Technology Perspectives...  

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

Technology Perspectives 2012 excerpt as IEA input to the Clean Energy Ministerial Tracking Clean Energy Progress Energy Technology Perspectives 2012 Pathways to a Clean Energy...

230

2011 Solar Decathlon - The Volunteer's Perspective | Department...  

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

2011 Solar Decathlon - The Volunteer's Perspective 2011 Solar Decathlon - The Volunteer's Perspective September 29, 2011 - 10:11am Addthis Volunteer Alison Mize demonstrates how to...

231

Smart Grid Stakeholder Roundtable Group Perspectives - September...  

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

Stakeholder Roundtable Group Perspectives - September 2009 Smart Grid Stakeholder Roundtable Group Perspectives - September 2009 This document is designed to capture key questions...

232

"Environmental Isotope Geochemistry": Past, Present Mark Baskaran  

E-Print Network (OSTI)

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

Baskaran, Mark

233

Radioactive isotopes on the Moon  

SciTech Connect

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

Davis, R. Jr.

1975-01-01T23:59:59.000Z

234

Perspectives on reactor safety  

SciTech Connect

The US Nuclear Regulatory Commission (NRC) maintains a technical training center at Chattanooga, Tennessee to provide appropriate training to both new and experienced NRC employees. This document describes a one-week course in reactor, safety concepts. The course consists of five modules: (1) historical perspective; (2) accident sequences; (3) accident progression in the reactor vessel; (4) containment characteristics and design bases; and (5) source terms and offsite consequences. The course text is accompanied by slides and videos during the actual presentation of the course.

Haskin, F.E. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Camp, A.L. [Sandia National Labs., Albuquerque, NM (United States)

1994-03-01T23:59:59.000Z

235

Cogeneration - A Utility Perspective  

E-Print Network (OSTI)

Cogeneration has become an extremely popular subject when discussing conservation and energy saving techniques. One of the key factors which effect conservation is the utility viewpoint on PURPA and cogeneration rule making. These topics are discussed from a utility perspective as how they influence utility participation in future projects. The avoided cost methodology is examined, and these payments for sale of energy to the utility are compared with utility industrial rates. In addition to utilities and industry, third party owner/operation is also a viable option to cogeneration. These options are also discussed as to their impact on the utility and the potential of these ownership arrangements.

Williams, M.

1983-01-01T23:59:59.000Z

236

Helium/Hydrogen Effects on the Properties of Materials for the APT Target/Blanket Region  

DOE Green Energy (OSTI)

This paper provides a technical basis to rationalize potential synergistic effects among displacement damage and the hydrogen and helium embrittlement processes and suggests that such synergistic effects may be of significant importance to component performance in intense spallation neutron sources.

Louthan, M.R.

1999-11-17T23:59:59.000Z

237

Nanostructuring of molybdenum and tungsten surfaces by low-energy helium ions  

Science Conference Proceedings (OSTI)

The formation of metallic nanostructures by exposure of molybdenum and tungsten surfaces to high fluxes of low energy helium ions is studied as a function of the ion energy, plasma exposure time, and surface temperature. Helium plasma exposure leads to the formation of nanoscopic filaments on the surface of both metals. The size of the helium-induced nanostructure increases with increasing surface temperature while the thickness of the modified layer increases with time. In addition, the growth rate of the nanostructured layer also depends on the surface temperature. The size of the nanostructure appears linked with the size of the near-surface voids induced by the low energy ions. The results presented here thus demonstrate that surface processing by low-energy helium ions provides an efficient route for the formation of porous metallic nanostructures.

De Temmerman, Gregory; Bystrov, Kirill; Zielinski, Jakub J.; Balden, Martin; Matern, Gabriele; Arnas, Cecile; Marot, Laurent [FOM Institute DIFFER, Ducth Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Max Planck Institute for Plasma Physics, EURATOM Association, 85748 Garching (Germany); Laboratoire PIIM, CNRS/Aix-Marseille Universit, 13397 Marseille (France); Department of Physics, University of Basel, Basel, CH-4056 (Switzerland)

2012-07-15T23:59:59.000Z

238

Carburization of austenitic alloys by gaseous impurities in helium  

SciTech Connect

The carburization behavior of Alloy 800H, Inconel Alloy 617 and Hastelloy Alloy X in helium containing various amounts of H/sub 2/, CO, CH/sub 4/, H/sub 2/O and CO/sub 2/ was studied. Corrosion tests were conducted in a temperature range from 649 to 1000/sup 0/C (1200 to 1832/sup 0/F) for exposure time up to 10,000 h. Four different helium environments, identified as A, B, C, and D, were investigated. Concentrations of gaseous impurities were 1500 ..mu..atm H/sub 2/, 450 ..mu..atm CO, 50 ..mu..atm CH/sub 4/ and 50 ..mu..atm H/sub 2/O for Environment A; 200 ..mu..atm H/sub 2/, 100 ..mu..atm CO, 20 ..mu..atm CH/sub 4/, 50 ..mu..atm H/sub 2/O and 5 ..mu..atm CO/sub 2/ for Environment B; 500 ..mu..atm H/sub 2/, 50 ..mu..atm CO, 50 ..mu..atm CH/sub 4/ and < 0.5 ..mu..atm H/sub 2/O for Environment C; and 500 ..mu..atm H/sub 2/, 50 ..mu..atm CO, 50 ..mu..atm CH/sub 4/ and 1.5 ..mu..atm H/sub 2/O for Environment D. Environments A and B were characteristic of high-oxygen potential, while C and D were characteristic of low-oxygen potential. The results showed that the carburization kinetics in low-oxygen potential environments (C and D) were significantly higher, approximately an order of magnitude higher at high temperatures, than those in high-oxygen potential environments (A and B) for all three alloys. Thermodynamic analyses indicated no significant differences in the thermodynamic carburization potential between low- and high-oxygen potential environments. It is thus believed that the enhanced carburization kinetics observed in the low-oxygen potential environments were related to kinetic effects. A qualitatively mechanistic model was proposed to explain the enhanced kinetics. The present results further suggest that controlling the oxygen potential of the service environment can be an effective means of reducing carburization of alloys.

Lai, G.Y.; Johnson, W.R.

1980-03-01T23:59:59.000Z

239

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

E-Print Network (OSTI)

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

Fradera, Jorge

2013-01-01T23:59:59.000Z

240

Background - Historical Perspective  

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

Historical Perspective Historical Perspective The Highway Trust Fund (HTF) was established in 1956 (Public Law 84-627) to ensure a dependable source of Federal funding to support highway programs. Prior to 1956, motor fuel and vehicle taxes went to the General Fund; although highway funding was provided from the General Fund, there was no relationship between fuel tax receipts and highway funding. Since 1956, legislation has periodically extended taxation of motor fuels and the HTF. The Transportation Equity Act for the 21st Century (TEA-21) extended the HTF through September 30, 2005. The HTF currently contains two accounts: the Highway Account and the Mass Transit Account; this document only concerns funds in the Highway Account. The income and outlays for transportation have increased steadily over time. The closing balance of funds in the Highway Account of the HTF remained at around $10 billion from 1983 through 1995. In 2000, the closing balance in the Highway Account was over $22.5 billion. It is necessary to maintain a balance of funds in the HTF to be able to meet unpaid commitments. This balance is not surplus funds because the HTF functions as a reimbursable program and must maintain funds for reimbursing obligations. The closing balance (income - outlays = closing balance) is shown in the following chart for 1957 through 2000 (the latest available data).

Note: This page contains sample records for the topic "helium isotope perspective" 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

Definition: Isotopic Analysis- Rock | Open Energy Information  

Open Energy Info (EERE)

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

242

THE GREEN BANK TELESCOPE H II REGION DISCOVERY SURVEY. IV. HELIUM AND CARBON RECOMBINATION LINES  

SciTech Connect

The Green Bank Telescope H II Region Discovery Survey (GBT HRDS) found hundreds of previously unknown Galactic regions of massive star formation by detecting hydrogen radio recombination line (RRL) emission from candidate H II region targets. Since the HRDS nebulae lie at large distances from the Sun, they are located in previously unprobed zones of the Galactic disk. Here, we derive the properties of helium and carbon RRL emission from HRDS nebulae. Our target sample is the subset of the HRDS that has visible helium or carbon RRLs. This criterion gives a total of 84 velocity components (14% of the HRDS) with helium emission and 52 (9%) with carbon emission. For our highest quality sources, the average {sup 4}He{sup +}/H{sup +} abundance ratio by number, (y {sup +}), is 0.068 {+-} 0.023(1{sigma}). This is the same ratio as that measured for the sample of previously known Galactic H II regions. Nebulae without detected helium emission give robust y {sup +} upper limits. There are 5 RRL emission components with y {sup +} less than 0.04 and another 12 with upper limits below this value. These H II regions must have either a very low {sup 4}He abundance or contain a significant amount of neutral helium. The HRDS has 20 nebulae with carbon RRL emission but no helium emission at its sensitivity level. There is no correlation between the carbon RRL parameters and the 8 {mu}m mid-infrared morphology of these nebulae.

Wenger, Trey V.; Bania, T. M. [Astronomy Department, 725 Commonwealth Avenue, Boston University, Boston, MA 02215 (United States)] [Astronomy Department, 725 Commonwealth Avenue, Boston University, Boston, MA 02215 (United States); Balser, Dana S. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA, 22903-2475 (United States)] [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA, 22903-2475 (United States); Anderson, L. D. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States)] [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States)

2013-02-10T23:59:59.000Z

243

Theory and modelling of helium enrichment in plasma experiments with pump limiters  

DOE Green Energy (OSTI)

Helium enrichment in the exhaust gas stream flowing from a hydrogen-helium plasma is studied using an analytical theory and Monte Carlo simulations. To provide a sensitive experimental test in a tokamak, an unusual configuration, inverted from traditional designs, is proposed for a pump limiter. The principle can be tested in other plasma devices as well. The theory suggests that for typical plasma edge conditions in a confinement device, namely, n = 10/sup 13/cm/sup -3/ and T/sub i/ = T/sub e/ approx. = 5-30eV, helium enrichment in the neutral gas exhaust stream can be very high, in the range 5 to 7, relative to the helium-hydrogen ratio in the plasma. Such high enrichment factors are achieved by exploiting the difference between the ionization rates of hydrogen and helium and the negligible helium charge exchange rate at these plasma conditions. A limiter arrangement is proposed in which the natural curvature of the toroidal magnetic field is used to isolate, using the plasma itself, the point of plasma neutralization from the location of the gas exhaust. The plasma region then acts to preferentially screen the recycling hydrogen by the processes of ionization and of charge-exchange-induced losses at open boundaries. The theory and analysis suggests that an experiment can provide a sensitive test of modules used to describe the plasma edge and of atomic and surface physics data used in these models.

Prinja, A.K.; Conn, R.W.

1984-01-01T23:59:59.000Z

244

Conditions For Successful Helium Detonations In Astrophysical Environments  

E-Print Network (OSTI)

Several models for type Ia-like supernovae events rely on the production of a self-sustained detonation powered by nuclear reactions.In the absence of hydrogen, the fuel that powers these detonations typically consists of either pure helium (He) or a mixture of carbon and oxygen (C/O). Studies that systematically determine the conditions required to initiate detonations in C/O material exist, but until now no analogous investigation of degenerate He matter has been conducted. We perform one-dimensional reactive hydrodynamical simulations at a variety of initial density and temperature combinations and find critical length scales for the initiation of He detonations that range between 1 -- $10^{10}$ cm. These sizes are consistently smaller than the corresponding Chapman-Jouguet (CJ) length scales by a factor of ~100, providing opportunities for thermonuclear explosions in a wider range of low mass white dwarfs (WDs) than previously thought possible. We find that virialized WDs with as little mass as 0.24 $M_\\o...

Holcomb, Cole; De Colle, Fabio; Ramirez-Ruiz, Enrico

2013-01-01T23:59:59.000Z

245

Once-ionized helium in superstrong magnetic fields  

E-Print Network (OSTI)

It is generally believed that magnetic fields of some neutron stars, the so-called magnetars, are enormously strong, up to 10^{14} - 10^{15} G. Recent investigations have shown that the atmospheres of magnetars are possibly composed of helium. We calculate the structure and bound-bound radiative transitions of the He^+ ion in superstrong fields, including the effects caused by the coupling of the ion's internal degrees of freedom to its center-of-mass motion. We show that He^+ in superstrong magnetic fields can produce spectral lines with energies of up to about 3 keV, and it may be responsible for absorption features detected recently in the soft X-ray spectra of several radio-quiet isolated neutron stars. Quantization of the ion's motion across a magnetic field results in a fine structure of spectral lines, with a typical spacing of tens electron-volts in magnetar-scale fields. It also gives rise to ion cyclotron transitions, whose energies and oscillator strengths depend on the state of the bound ion.

George G. Pavlov; Victor G. Bezchastnov

2005-05-23T23:59:59.000Z

246

USE OF THE MODULAR HELIUM REACTOR FOR HYDROGEN PRODUCTION  

DOE Green Energy (OSTI)

OAK-B135 A significant ''Hydrogen Economy'' is predicted that will reduce our dependence on petroleum imports and reduce pollution and greenhouse gas emissions. Hydrogen is an environmentally attractive fuel that has the potential to displace fossil fuels, but contemporary hydrogen production is primarily based on fossil fuels. The author has recently completed a three-year project for the US Department of Energy (DOE) whose objective was to ''define an economically feasible concept for production of hydrogen, using an advanced high-temperature nuclear reactor as the energy source''. Thermochemical water-slitting, a chemical process that accomplishes the decomposition of water into hydrogen and oxygen, met this objective. The goal of the first phase of this study was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen, and to select one for further detailed consideration. They selected the Sulfur-Iodine cycle. In the second phase, they reviewed all the basic reactor types for suitability to provide the high temperature heat needed by the selected thermochemical water splitting cycle and chose the helium gas-cooled reactor. In the third phase they designed the chemical flowsheet for the thermochemical process and estimated the efficiency and cost of the process and the projected cost of producing hydrogen. These results are summarized in this report.

SCHULTZ,KR

2003-09-01T23:59:59.000Z

247

Helium Behavior in Oxide Nuclear Fuels: First Principles Modeling  

Science Conference Proceedings (OSTI)

UO2 and (U, Pu)O2 solid solutions (the so-called MOX) nowadays are used as commercial nuclear fuels in many countries. One of the safety issues during the storage of these fuels is related to their self-irradiation that produces and accumulates point defects and helium therein. We present density functional theory (DFT) calculations for UO2, PuO2 and MOX containing He atoms in octahedral interstitial positions. In particular, we calculated basic MOX properties and He incorporation energies as functions of Pu concentration within the spin-polarized, generalized gradient approximation (GGA) DFT calculations. We also included the on-site electron correlation corrections using the Hubbard model (in the framework of the so-called DFT + U approach). We found that PuO2 remains semiconducting with He in the octahedral position while UO2 requires a specific lattice distortion. Both materials reveal a positive energy for He incorporation, which, therefore, is an exothermic process. The He incorporation energy increases with the Pu concentration in the MOX fuel.

Gryaznov, D.; Rashkeev, Sergey N.; Kotomin, E. A.; Heifets, Eugene; Zhukovskii, Yuri F.

2010-10-01T23:59:59.000Z

248

Demonstration of Tritium Extraction from Tritiated Methane in Helium by Utilizing Plasma Decomposition  

Science Conference Proceedings (OSTI)

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

Kazunari Katayama; Satoshi Fukada; Masabumi Nishikawa

249

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

SciTech Connect

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

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

2002-06-11T23:59:59.000Z

250

Measurement of Trace Uranium Isotopes  

Science Conference Proceedings (OSTI)

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

Matthew G. Watrous; James E. Delmore

2011-05-01T23:59:59.000Z

251

Analysis of hydrogen isotope mixtures  

DOE Patents (OSTI)

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

Villa-Aleman, E.

1992-12-31T23:59:59.000Z

252

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

253

Hartree-Fock calculations for the photoionisation of helium and helium-like ions in neutron star magnetic fields  

E-Print Network (OSTI)

We derive the photoionisation cross section in dipole approximation for many-electron atoms and ions for neutron star magnetic field strengths in the range of 10^7 to 10^9 T. Both bound and continuum states are treated in adiabatic approximation in a self-consistent way. Bound states are calculated by solving the Hartree-Fock-Roothaan equations using finite-element and B-spline techniques while the continuum orbital is calculated by direct integration of the Hartree-Fock equations in the mean-field potential of the remaining bound orbitals. We take into account mass and photon density in the neutron star's atmosphere as well as thermal occupation of the levels. The data are of importance for the quantitative interpretation of observed x-ray spectra that originate from the thermal emission of isolated neutron stars. They can serve as input for modeling neutron star atmospheres as regards chemical composition, magnetic field strength, temperature, and redshift. Our main focus in this paper lies on helium, heliu...

Kersting, Thorsten; Diemand, Peter; Wunner, Günter

2013-01-01T23:59:59.000Z

254

journal Environmental Health Perspectives  

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

Pollutant exposures from unvented gas cooking burners A simulation Pollutant exposures from unvented gas cooking burners A simulation based assessment for Southern California journal Environmental Health Perspectives year month abstract p Background Residential natural gas cooking burners NGCBs can emit substantial quantities of pollutants and they are typically used without venting p p Objective Quantify pollutant concentrations and occupant exposures resulting from NGCB use in California homes p p Methods A mass balance model was applied to estimate time dependent pollutant concentrations throughout homes and the exposure concentrations experienced by individual occupants The model was applied to estimate nitrogen dioxide NO2 carbon monoxide CO and formaldehyde HCHO concentrations for one week each in summer and winter for a representative sample

255

Perspectives on Energy Efficiency  

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

2 2 nd U.S.-China Energy Efficiency Forum Dr. Arun Majumdar Director Advanced Research Projects Agency- Energy U.S. Department of Energy May 6, 2011 Berkeley, California Perspectives on Energy Efficiency 2 | U.S. Department of Energy energy.gov Policy Framework R&D - Advance innovative technologies for appliances, equipment, and products - Integrated buildings approaches Market Priming - Pull new products, practices and services into market faster at scale - Technical support to ENERGY STAR / new higher tier Codes & Standards - Leverage market priming and advanced technologies - Broaden coverage and update frequently to capture savings opportunities Increasing Energy Efficiency (Metrics) Number of Unit Sales At least $23B net benefits Over 3.5 quads saved annually Over 2

256

End User Perspective - Industrial  

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

Solid State Research Center Solid State Research Center DOE Fuel Cell Portable Power Workshop End User Perspective - Industrial Consumer Electronics Power (< 20-50W) Department of Energy Fuel Cell Portable Power Workshop Jerry Hallmark Manager Energy Technologies Lab Motorola Labs Solid State Research Center DOE Fuel Cell Portable Power Workshop Outline * Energy & Power of Portable Devices * Fuel Cell Applications & Cost * Key Requirements & Challenges * Fuels for Portable Fuel Cells * Fuel Transportation Regulations and Standards * Methanol Fuel Cells - Direct Methanol Fuel Cells - Reformed Methanol Fuel Cells * Technical Challenges 2 Solid State Research Center DOE Fuel Cell Portable Power Workshop Portable Electronics Yearly Energy Usage  :KU 1990 1980  :KU

257

Maximum Reasonable Radioxenon Releases from Medical Isotope Production Facilities and Their Effect on Monitoring Nuclear Explosions  

SciTech Connect

Fission gases such as 133Xe are used extensively for monitoring the world for signs of nuclear testing in systems such as the International Monitoring System (IMS). These gases are also produced by nuclear reactors and by fission production of 99Mo for medical use. Recently, medical isotope production facilities have been identified as the major contributor to the background of radioactive xenon isotopes (radioxenon) in the atmosphere (Saey, et al., 2009). These releases pose a potential future problem for monitoring nuclear explosions if not addressed. As a starting point, a maximum acceptable daily xenon emission rate was calculated, that is both scientifically defendable as not adversely affecting the IMS, but also consistent with what is possible to achieve in an operational environment. This study concludes that an emission of 5×109 Bq/day from a medical isotope production facility would be both an acceptable upper limit from the perspective of minimal impact to monitoring stations, but also appears to be an achievable limit for large isotope producers.

Bowyer, Ted W.; Kephart, Rosara F.; Eslinger, Paul W.; Friese, Judah I.; Miley, Harry S.; Saey, Paul R.

2013-01-01T23:59:59.000Z

258

GM's Perspective on Advanced Biofuels | Department of Energy  

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

GM's Perspective on Advanced Biofuels GM's Perspective on Advanced Biofuels Bioufuels GM GM's Perspective on Advanced Biofuels More Documents & Publications Algae Biofuels...

259

D0 Silicon Upgrade: Commissioning Test Results for D-Zero's Helium Refrigerator  

Science Conference Proceedings (OSTI)

The test objectives are: (1) Make liquid helium and measure refrigerator capacity; (2) Measure liquid helium dewar heat leak, transfer line heat leak, and liquid nitrogen consumption rates; (3) Operate all cryogenic transfer lines; (4) Get some running time on all components; (5) Debug mechanical components, instrumentation, DMACs user interface, tune loops, and otherwise shake out any problems; (6) Get some operating time in to get familiar with system behavior; (7) Revise and/or improve operating procedures to actual practice; and (8) Identify areas for future improvement. D-Zero's stand alone helium refrigerator (STAR) liquified helium at a rate of 114 L/hr. This is consistent with other STAR installations. Refrigeration capacity was not measured due to lack of a calibrated heat load. Measured heat leaks were within design values. The helium dewar loss was measured at 2 to 4 watts or 9% per day, the solenoid and VLPC helium transfer lines had a heat leak of about 20 watts each. The liquid nitrogen consumption rates of the mobile purifier, STAR, and LN2 subcooler were measured at 20 gph, 20 to 64 gph, and 3 gph respectively. All cryogenic transfer lines including the solenoid and visible light photon counter (VLPC) transfer lines were cooled to their cryogenic operating temperatures. This included independent cooling of nitrogen shields and liquid helium components. No major problems were observed. The system ran quite well. Many problems were identified and corrected as they came up. Areas for improvement were noted and will be implemented in the future. The instrumentation and control system operated commendably during the test. The commissioning test run was a worthwhile and successful venture.

Rucinski, Russ; /Fermilab

1997-06-30T23:59:59.000Z

260

ALTERNATIVES TO HELIUM-3 FOR NEUTRON MULTIPLICITY DETECTORS  

Science Conference Proceedings (OSTI)

Collaboration between the Pacific Northwest National Laboratory (PNNL) and the Los Alamos National Laboratory (LANL) is underway to evaluate neutron detection technologies that might replace the high-pressure helium (3He) tubes currently used in neutron multiplicity counter for safeguards applications. The current stockpile of 3He is diminishing and alternatives are needed for a variety of neutron detection applications including multiplicity counters. The first phase of this investigation uses a series of Monte Carlo calculations to simulate the performance of an existing neutron multiplicity counter configuration by replacing the 3He tubes in a model for that counter with candidate alternative technologies. These alternative technologies are initially placed in approximately the same configuration as the 3He tubes to establish a reference level of performance against the 3He-based system. After these reference-level results are established, the configurations of the alternative models will be further modified for performance optimization. The 3He model for these simulations is the one used by LANL to develop and benchmark the Epithermal Neutron Multiplicity Counter (ENMC) detector, as documented by H.O. Menlove, et al. in the 2004 LANL report LA-14088. The alternative technologies being evaluated are the boron-tri-fluoride-filled proportional tubes, boron-lined tubes, and lithium coated materials previously tested as possible replacements in portal monitor screening applications, as documented by R.T. Kouzes, et al. in the 2010 PNNL report PNNL-72544 and NIM A 623 (2010) 1035–1045. The models and methods used for these comparative calculations will be described and preliminary results shown

Ely, James H.; Siciliano, Edward R.; Swinhoe, Martyn T.

2012-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

Helium-cooled molten-salt fusion breeder  

Science Conference Proceedings (OSTI)

We present a new conceptual design for a fusion reactor blanket that is intended to produce fissile material for fission power plants. Fast fission is suppressed by using beryllium instead of uranium to multiply neutrons. Thermal fission is suppressed by minimizing the fissile inventory. The molten-salt breeding medium (LiF + BeF/sub 2/ + ThF/sub 4/) is circulated through the blanket and to the on-line processing system where /sup 233/U and tritium are continuously removed. Helium cools the blanket and the austenitic steel tubes that contain the molten salt. Austenitic steel was chosen because of its ease of fabrication, adequate radiation-damage lifetime, and low corrosion by molten salt. We estimate that a breeder having 3000 MW of fusion power will produce 6500 kg of /sup 233/U per year. This amount is enough to provide makeup for 20 GWe of light-water reactors per year or twice that many high-temperature gas-cooled reactors or Canadian heavy-water reactors. Safety is enhanced because the afterheat is low and blanket materials do not react with air or water. The fusion breeder based on a pre-MARS tandem mirror is estimated to cost $4.9B or 2.35 times a light-water reactor of the same power. The estimated cost of the /sup 233/U produced is $40/g for fusion plants costing 2.35 times that of a light-water reactor if utility owned or $16/g if government owned.

Moir, R.W.; Lee, J.D.; Fulton, F.J.; Huegel, F.; Neef, W.S. Jr.; Sherwood, A.E.; Berwald, D.H.; Whitley, R.H.; Wong, C.P.C.; Devan, J.H.

1984-12-01T23:59:59.000Z

262

Hydrogen and helium traces in type Ib-c supernovae  

E-Print Network (OSTI)

The spectroscopic properties of a selected optical photospheric spectra of core collapse supernovae (CCSNe) are investigated.Special attention is devoted to traces of hydrogen at early phases. The generated spectra are found to match the observed ones reasonably well, including a list of only 23 candidate ions. Guided by SN Ib 1990I, the observed trough near 6300\\AA is attributed to H$\\alpha$ in almost all Type Ib events, although in some objects it becomes too weak to be discernible, especially at later phases. Alternative line identifications are discussed. Differences in the way hydrogen manifests its presence within CCSNe are highlighted. In Type Ib SNe, the H$\\alpha$ contrast velocity (i.e. line velocity minus the photospheric velocity) seems to increase with time at early epochs, reaching values as high as 8000 km s$^{-1}$ around 15-20 days after maximum and then remains almost constant. The derived photospheric velocities, indicate a lower velocity for Type II SNe 1987A and 1999em as compared to SN Ic 1994I and SN IIb 1993J, while Type Ib events display a somewhat larger variation. The scatter, around day 20, is measured to be $\\sim$5000 km s$^{-1}$. Following two simple approaches, rough estimates of ejecta and hydrogen masses are given. A mass of hydrogen of approximately 0.02 $M_\\odot$ is obtained for SN 1990I, while SNe 1983N and 2000H ejected $\\sim$0.008 $M_\\odot$ and $\\sim$0.08 $M_\\odot$ of hydrogen, respectively. SN 1993J has a higher hydrogen mass, $\\sim 0.7$ $M_\\odot$ with a large uncertainty. A low mass and thin hydrogen layer with very high ejection velocities above the helium shell, is thus the most likely scenario for Type Ib SNe. Some interesting and curious issues relating to oxygen lines suggest future investigations.

A. Elmhamdi; I. J. Danziger; D. Branch; B. Leibundgut; E. Baron; R. P. Kirshner

2005-12-22T23:59:59.000Z

263

Nuclear Energy Protocol for Research Isotopes Owen Lowe  

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

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

264

A perspective of generative reuse  

Science Conference Proceedings (OSTI)

This paper presents a perspective of generative reuse technologies as they have evolved over the last 15 years or so and a discussion of how generative reuse addresses some key reuse problems. Over that time period, a number of different ...

Ted J. Biggerstaff

1998-01-01T23:59:59.000Z

265

Financial crisis : through various perspectives  

E-Print Network (OSTI)

The 2007 financial crisis can be viewed from various perspectives. First, it can be explained in a wider macroeconomic context, for example by looking at the housing bubble. Monetary policy can be explained according to ...

Kim, Joon Hee

2010-01-01T23:59:59.000Z

266

Strategic Isotope Production | ornl.gov  

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

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

267

Electromagnetic Isotope Separation Lab (EMIS) | ORNL  

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

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

268

Stable Isotope Enrichment Capabilities at ORNL  

SciTech Connect

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

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

2013-01-01T23:59:59.000Z

269

METHOD AND APPARATUS FOR COLLECTING ISOTOPES  

DOE Patents (OSTI)

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

Leyshon, W.E.

1957-08-01T23:59:59.000Z

270

Assessment of Embrittlement of VHTR Structural Alloys in Impure Helium Environments  

SciTech Connect

The helium coolant in high-temperature reactors inevitably contains low levels of impurities during steady-state operation, primarily consisting of small amounts of H{sub 2}, H{sub 2}O, CH{sub 4}, CO, CO{sub 2}, and N{sub 2} from a variety of sources in the reactor circuit. These impurities are problematic because they can cause significant long-term corrosion in the structural alloys used in the heat exchangers at elevated temperatures. Currently, the primary candidate materials for intermediate heat exchangers are Alloy 617, Haynes 230, Alloy 800H, and Hastelloy X. This project will evaluate the role of impurities in helium coolant on the stress-assisted grain boundary oxidation and creep crack growth in candidate alloys at elevated temperatures. The project team will: • Evaluate stress-assisted grain boundary oxidation and creep crack initiation and crack growth in the temperature range of 500-850°C in a prototypical helium environment. • Evaluate the effects of oxygen partial pressure on stress-assisted grain boundary oxidation and creep crack growth in impure helium at 500°C, 700°C, and 850°C respectively. • Characterize the microstructure of candidate alloys after long-term exposure to an impure helium environment in order to understand the correlation between stress-assisted grain boundary oxidation, creep crack growth, material composition, and impurities in the helium coolant. • Evaluate grain boundary engineering as a method to mitigate stress-assisted grain boundary oxidation and creep crack growth of candidate alloys in impure helium. The maximum primary helium coolant temperature in the high-temperature reactor is expected to be 850-1,000°C.Corrosion may involve oxidation, carburization, or decarburization mechanisms depending on the temperature, oxygen partial pressure, carbon activity, and alloy composition. These corrosion reactions can substantially affect long-term mechanical properties such as crack- growth rate and fracture toughness, creep rupture, and fatigue. Although there are some studies on the effects of impurities in helium coolant on creep rupture and fatigue strength, very little is known about their effects on creep crack initiation and crack growth rate at elevated temperatures.

Crone, Wendy; Cao, Guoping; Sridhara, Kumar

2013-05-31T23:59:59.000Z

271

Isotopic Analysis (Not Available) | Open Energy Information  

Open Energy Info (EERE)

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

272

It's Elemental - Isotopes of the Element Nobelium  

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

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

273

It's Elemental - Isotopes of the Element Fermium  

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

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

274

WEB RESOURCE: Exploring the Table of Isotopes  

Science Conference Proceedings (OSTI)

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

275

Available Technologies: Real Time High Throughput Isotopic ...  

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

276

Zeolite Cryopumps for Hydrogen Isotopes Transportation  

Science Conference Proceedings (OSTI)

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

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

277

It's Elemental - Isotopes of the Element Rhodium  

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

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

278

It's Elemental - Isotopes of the Element Promethium  

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

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

279

It's Elemental - Isotopes of the Element Niobium  

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

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

280

It's Elemental - Isotopes of the Element Indium  

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

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

Note: This page contains sample records for the topic "helium isotope perspective" 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

It's Elemental - Isotopes of the Element Cerium  

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

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

282

NIDC: Online Catalog of Isotope Products Home  

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

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

283

HFIR | High Flux Isotope Reactor | ORNL  

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

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

284

Isotopic Exchange in Air Detritiation Dryers  

Science Conference Proceedings (OSTI)

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

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

285

Estimation of tritium and helium inventory in the tritium handling system in Korea  

Science Conference Proceedings (OSTI)

In Korea, the Wolsong Tritium Removal Facility (WTRF) is under construction to reduce the amount of tritium present in the moderator and coolant of the CANDU type Wolsong nuclear power plants. Recently, a study on the tritium handling system for recovery of the tritium collected from the WTRF was started. Some tritium would enter the steel of the container walls and subsequently decay to helium. This helium can deteriorate the mechanical properties of the material of the tritium handling system. To evaluate the tritium and helium inventory in the stainless steel wall of this system, the time-dependent diffusion equation was developed, solved and the results are presented in this paper. These results were compared to previous work that evaluated the tritium inventory in the stainless steel wall of 50-L tritium containers. Tritium and helium concentration profiles and the corresponding inventories were evaluated with respect to the various parameters such as exposure time, temperature, and partial pressure. After 24 years, the helium inventory in the wall of the tritium handling system exceeds the tritium inventory. (authors)

Yook, D.; Lee, S.; Lee, K. [Dept. of Nuclear Eng., KAIST, 373-1, Kusong-dong, Yusong-gu, Daejon 305-701 (Korea, Republic of); Song, K. M.; Shon, S. H. [KEPRI, 103-16 Munji-Dong, Yuseong-Gu, Daejeon, 305-380 (Korea, Republic of)

2008-07-15T23:59:59.000Z

286

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

E-Print Network (OSTI)

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

287

Perspectives of Nuclear Physics  

E-Print Network (OSTI)

The organizers of this meeting have asked me to present perspectives of nuclear physics. This means to identify the areas where nuclear physics will be expanding in the next future. In six chapters a short overview of these areas will be given, where I expect that nuclear physics willdevelop quite fast: A. Quantum Chromodynamics and effective field theories in the confinement region; B. Nuclear structure at the limits; C. High energy heavy ion collisions; D. Nuclear astrophysics; E. Neutrino physics; F. Test of physics beyond the standard model by rare processes. After a survey over these six points I will pick out a few topics where I will go more in details. There is no time to give for all six points detailed examples. I shall discuss the following examples of the six topics mentionned above: 1. The perturbative chiral quark model and the nucleon $\\Sigma$-term, 2. VAMPIR (Variation After Mean field Projection In Realistic model spaces and with realistic forces) as an example of the nuclear structure renais...

Faessler, A

2002-01-01T23:59:59.000Z

288

PERSPECTIVES OF NUCLEAR PHYSICS  

E-Print Network (OSTI)

The organizers of this meeting have asked me to present perspectives of nuclear physics. This means to identify the areas where nuclear physics will be expanding in the next future. In six chapters a short overview of these areas will be given, where I expect that nuclear physics will develop quite fast: (1) Quantum Chromodynamics and effective field theories in the confinement region. (2) Nuclear structure at the limits. (3) High energy heavy ion collisions. (4) Nuclear astrophysics. (5) Neutrino physics. (6) Test of physics beyond the standard model by rare processes. After a survey over these six points I will pick out a few topics where I will go more in details. There is no time to give for all six points detailed examples. I shall discuss the following examples of the six topics mentionned above: (1) The perturbative chiral quark model and the nucleon ?-term. (2) VAMPIR (Variation After Mean field Projection In Realistic model spaces and with realistic forces) as an example of the nuclear structure renaissance. (3) Measurement of important astrophysical nuclear reactions in the Gamow peak. (4) The solar neutrino problem. As examples for testing new physics beyond the standard model by rare processes I had prepared to speak about the measurement of the electric neutron dipole moment and of the neutrinoless double beta decay. But the time is limited and so I have to skip these points, although they are extremely interesting.

Amand Faessler

2002-01-01T23:59:59.000Z

289

Mercury Isotope Fractionation by Environmental Transport and Transformation Processes  

E-Print Network (OSTI)

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

Koster van Groos, Paul Gijsbert

2011-01-01T23:59:59.000Z

290

HELIUM SHELL DETONATIONS ON LOW-MASS WHITE DWARFS AS A POSSIBLE EXPLANATION FOR SN 2005E  

SciTech Connect

Recently, several Type Ib supernovae (SNe; with the prototypical SN 2005E) have been shown to have atypical properties. These SNe are faint (absolute peak magnitude of {approx} - 15) and fast SNe that show unique composition. They are inferred to have low ejecta mass (a few tenths of a solar mass) and to be highly enriched in calcium, but poor in silicon elements and nickel. These SNe were therefore suggested to belong to a new class of calcium-rich faint SNe explosions. Their properties were proposed to be the result of helium detonations that may occur on helium accreting white dwarfs. In this paper, we theoretically study the scenario of helium detonations and focus on the results of detonations in accreted helium layers on low-mass carbon-oxygen (CO) cores. We present new results from one-dimensional simulations of such explosions, including their light curves and spectra. We find that when the density of the helium layer is low enough the helium detonation produces large amounts of intermediate elements, such as calcium and titanium, together with a large amount of unburnt helium. Alternatively, enough carbon enrichment of the accreted helium as a result of convective undershoot at the early stages of the runaway can avoid the production of iron group elements as the alpha particles are consumed avoiding iron production. Our results suggest that the properties of calcium-rich faint SNe could indeed be consistent with the helium-detonation scenario on small CO cores. Above a certain density (larger CO cores) the detonation leaves mainly {sup 56}Ni and unburnt helium, and the predicted spectrum will unlikely fit the unique features of this class of SNe. Finally, none of our studied models reproduces the bright, fast-evolving light curves of another type of peculiar SNe suggested to originate in helium detonations (SNe 1885A, 1939B, and 2002bj).

Waldman, Roni; Livne, Eli; Glasner, Ami [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Sauer, Daniel [Stockholm University, Department for Astronomy, AlbaNova University Center, 106 91 Stockholm (Sweden); Perets, Hagai [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Mazzali, Paolo [Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany); Truran, James W. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)

2011-09-01T23:59:59.000Z

291

Neutron-induced dpa, transmutations, gas production, and helium embrittlement of fusion materials  

E-Print Network (OSTI)

In a fusion reactor materials will be subjected to significant fluxes of high-energy neutrons. As well as causing radiation damage, the neutrons also initiate nuclear reactions leading to changes in the chemical composition of materials (transmutation). Many of these reactions produce gases, particularly helium, which cause additional swelling and embrittlement of materials. This paper investigates, using a combination of neutron-transport and inventory calculations, the variation in displacements per atom (dpa) and helium production levels as a function of position within the high flux regions of a recent conceptual model for the "next-step" fusion device DEMO. Subsequently, the gas production rates are used to provide revised estimates, based on new density-functional-theory results, for the critical component lifetimes associated with the helium-induced grain-boundary embrittlement of materials. The revised estimates give more optimistic projections for the lifetimes of materials in a fusion power plant co...

Gilbert, M R; Nguyen-Manh, D; Zheng, S; Packer, L W; Sublet, J -Ch

2013-01-01T23:59:59.000Z

292

Cooling Strings of Superconducting Devices below 2 K the Helium II Bayonet Heat Exchanger  

E-Print Network (OSTI)

High-energy particle accelerators and colliders contain long strings of superconducting devices - acceleration RF cavities and magnets - operating at high field, which may require cooling in helium II below 2 K. In order to maintain adequate operating conditions, the applied or generated heat loads must be extracted and transported with minimum temperature difference. Conventional cooling schemes based on conductive or convective heat transport in pressurized helium II very soon reach their intrinsic limits of thermal impedance over extended lengths. We present the concept of helium II bayonet heat exchanger, which has been developed at CERN for the magnet cooling scheme of the Large Hadron Collider (LHC), and describe its specific advantages as a slim, quasi-isothermal heat sink. Experimental results obtained on several test set-ups, and a prototype magnet string have permitted to validate its performance and sizing rules, for transporting linear heat loads in the W.m-1 range over distances of several tens o...

Lebrun, P; Tavian, L; Van Weelderen, R

1998-01-01T23:59:59.000Z

293

Helium and Hydrogen Release Measurements on Various Alloys Irradiated in SINQ  

SciTech Connect

Three irradiations have been performed in the Swiss Spallation Neutron Source (SINQ) to establish a materials database for mixed proton and neutron fluxes for future spallation neutron and other accelerator sources. Materials included in the second irradiation, STIP-II, included mainly austenitic and martensitic steels. Samples of 316LN, F82H, Al, and Zircaloy-2 from STIP ?II have been analyzed for their total helium and hydrogen contents and their release characteristics. In terms of total gas content, the helium and hydrogen results are similar to those observed earlier from STIP-I. Specifically, the helium contents tended to be somewhat higher (up to 50%) than calculated for both low and high dose samples. 3He/4He ratios were generally in agreement with expectations except for the Ziracaloy-2 which showed very low values, likely from increased 3He generation from decay of irradiation-generated tritium. Hydrogen contents on the other hand tended inversely with dose, suggesting increased hydrogen loss at the higher dose (and higher temperature) locations from diffusion. Hydrogen levels in the Zircaloy were considerably higher than expected ({approx}10,000 to 25,000 appm), suggesting additional pickup of hydrogen from the irradiation environment. Hydrogen levels in the aluminum were similar to predicted. Helium and hydrogen release measurements from the temperature ramp experiments showed considerable levels of deuterium and tritium species which generally mirrored those of hydrogen. Hydrogen release occurred from about 300 for the aluminum to about 800 C for the Zircaloy-2. For the Zircaloy-2 and the steels, helium release began to occur at about 1100 C, which is consistent with previous measurements on irradiated steels. For the aluminum, helium release began at just under 600 C.

Oliver, Brian M.; Dai, Yong; Causey, Rion A.

2006-09-15T23:59:59.000Z

294

ISOTOPES  

E-Print Network (OSTI)

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

295

ISOTOPES  

E-Print Network (OSTI)

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

296

ISOTOPES  

E-Print Network (OSTI)

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

297

ISOTOPES  

E-Print Network (OSTI)

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

298

ISOTOPES  

E-Print Network (OSTI)

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

299

ISOTOPES  

E-Print Network (OSTI)

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

300

ISOTOPES  

E-Print Network (OSTI)

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

Lederer, C. Michael

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

Dynamical aspects of isotopic scaling  

E-Print Network (OSTI)

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

M. Veselsky

2006-07-17T23:59:59.000Z

302

Advanced Mass Spectrometers for Hydrogen Isotope Analyses  

DOE Green Energy (OSTI)

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

Chastagner, P.

2001-08-01T23:59:59.000Z

303

The Quest for the Heaviest Uranium Isotope  

E-Print Network (OSTI)

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

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

2011-07-06T23:59:59.000Z

304

5, 547577, 2008 Isotope hydrology of  

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

305

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

306

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

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

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

307

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

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

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

308

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

Open Energy Info (EERE)

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

309

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

Open Energy Info (EERE)

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

310

CALIFORNIUM ISOTOPES FROM BOMBARDMENT OF URANIUM WITH CARBON IONS  

E-Print Network (OSTI)

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

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

2008-01-01T23:59:59.000Z

311

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

Open Energy Info (EERE)

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

312

Solutions for Liquid Nitrogen Pre-Cooling in Helium Refrigeration Cycles  

E-Print Network (OSTI)

Pre-cooling of helium by means of liquid nitrogen is the oldest and one of the most common process features used in helium liquefiers and refrigerators. Its two principle tasks are to allow or increase the rate of pure liquefaction, and to permit the initial cool-down of large masses to about 80 K. Several arrangements for the pre-cooling process are possible depending on the desired application. Each arrangement has its proper advantages and drawbacks. The aim of this paper is to review the possible process solutions for liquid nitrogen pre-cooling and their particularities.

Wagner, U

2000-01-01T23:59:59.000Z

313

Detection and Imaging of He{sub 2} Molecules in Superfluid Helium  

SciTech Connect

We present data that show a cycling transition can be used to detect and image metastable He{sub 2} triplet molecules in superfluid helium. We demonstrate that limitations on the cycling efficiency due to the vibrational structure of the molecule can be mitigated by the use of repumping lasers. Images of the molecules obtained using the method are also shown. This technique gives rise to a new kind of ionizing radiation detector. The use of He{sub 2} triplet molecules as tracer particles in the superfluid promises to be a powerful tool for visualization of both quantum and classical turbulence in liquid helium.

Rellergert, W. G.; Cahn, S. B.; Garvan, A.; Hanson, J. C.; Lippincott, W. H.; Nikkel, J. A.; McKinsey, D. N. [Department of Physics, Yale University, New Haven, Connecticut 06520 (United States)

2008-01-18T23:59:59.000Z

314

Particle Detection in Superfluid Helium: R&D for Low Energy Solar Neutrinos  

DOE Green Energy (OSTI)

This report presents a summary of the results from R&D conducted as a feasibility study in the Department of Physics of Brown University for detection of low energy solar neutrinos utilizing a superfluid helium target. The report outlines the results in several areas: 1) development of experimental facilities, 2) energy deposition by electrons and alphas in superfluid helium, 3) development of wafer and metallic magnetic calorimeters, 4) background studies, 5) coded apertures and conceptual design, 6) Detection of single electrons and 7) a simulation of expected performance of a full scale device. Recommendations for possible future work are also presented. A bibliography of published papers and unpublished doctoral theses is included.

Lanou, Robert E., Jr.

2006-03-31T23:59:59.000Z

315

Nanometer-scale tunnel formation in metallic glass by helium ion irradiation  

SciTech Connect

We have shown that upon high fluence helium ion irradiation, metallic glass Cu{sub 50}Zr{sub 45}Ti{sub 5} becomes highly porous at the depth of the helium projected range. The resulting porous region is characterized by the formation of a tunnel like structure and self-linkage of nanometer size gas bubbles. Furthermore, the irradiation leads to the formation of nanometer size Cu{sub x}Zr{sub y} crystals that are randomly distributed. The results of this study indicate that the He-filled bubbles have attractive interactions and experience considerable mobility. Movement of the bubbles is believed to be assisted by ballistic collisions.

Shao Lin [Department of Nuclear Engineering, Texas A and M University, College Station, Texas 77843 (United States); Materials Science and Engineering Program, Texas A and M University, College Station, Texas 77843 (United States); Gorman, Brian P. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401 (United States); Aitkaliyeva, Assel [Materials Science and Engineering Program, Texas A and M University, College Station, Texas 77843 (United States); David Theodore, N. [CHD-Fab, Freescale Semiconductor, Inc., Chandler, Arizona 85224 (United States); Xie Guoqiang [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2012-07-23T23:59:59.000Z

316

High-temperature gas-cooled reactor helium compatibility studies: results of 10,000-hour exposure of selected alloys in simulated reactor helium  

SciTech Connect

Work on the HTGR Helium Compatibility Task accomplished during the period March 31, 1977 through September 30, 1979, is documented in this report. Emphasis is on the results and analyses of creep data to 10,000 h and the detailed metallurgical evaluations performed on candidate alloy specimens tested for up to 10,000 h. Long-term creep and unstressed aging data in controlled-impurity helium and in air at 800, 900, and 1000/sup 0/C are reported for alloys included in the program in FY-76, including the wrought solid-solution-strengthened alloys, Hastelloy X, Hastelloy S, RA 333, and HD 556, and the centrifugally cast austenitic alloys, HK 40, Supertherm, Manaurite 36X, Manaurite 36XS, and Manaurite 900.

Lechtenberg, T.A.; Stevenson, R.D.; Johnson, W.R.

1980-05-01T23:59:59.000Z

317

SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH A SOLAR CYCLE  

E-Print Network (OSTI)

SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH A SOLAR CYCLE Justin C. Kasper,1 Michael L. Stevens, and Alan J. Lazarus Kavli Institute for Astrophysics of the variation of the relative abundance of helium to hydrogen in the solar wind as a function of solar wind

Richardson, John

318

Experimental measurement methods and data on irradiation of functional design materials by helium ions in linear accelerator  

E-Print Network (OSTI)

The experimental research on the irradiation of the functional design materials by the Helium ions in the linear accelerator is conducted. The experimental measurements techniques and data on the irradiation of the functional design materials by the Helium ions with the energy up to 4 MeV, including the detailed scheme of experimental measurements setup, are presented. The new design of accelerating structure of the IH-type such as POS-4, using the method of alternate-phase focusing with the step-by-step change of the synchronous phase along the focusing periods in a linear accelerator, is developed with the aim to irradiate the functional design materials by the Helium ions. The new design of the injector of the charged Helium ions with the energy of 120 KeV at the output of an accelerating tube and the accelerating structure of the type of POS-4 for the one time charged Helium ions acceleration in the linear accelerator are researched and developed. The special chamber for the irradiation of functional design materials by the Helium ions is also created. In the process of experiment, the temperature of a sample, the magnitude of current of Helium ions beam and the irradiation dose of sample are measured precisely. The experimental measurement setup and techniques are fully tested and optimized in the course of the research on the electro-physical properties of irradiated samples and the thermal-desorption of Helium ions in a wide range of temperatures

R. A. Anokhin; V. N. Voyevodin; S. N. Dubnyuk; A. M. Egorov; B. V. Zaitsev; A. F. Kobets; O. P. Ledenyov; K. V. Pavliy; V. V. Ruzhitsky; G. D. Tolstolutskaya

2013-09-03T23:59:59.000Z

319

It's Elemental - Isotopes of the Element Radon  

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

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

320

It's Elemental - Isotopes of the Element Francium  

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

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

Note: This page contains sample records for the topic "helium isotope perspective" 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

Selected Isotopes for Optimized Fuel Assembly Tags  

SciTech Connect

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

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

2008-10-01T23:59:59.000Z

322

Perspectives GmbH | Open Energy Information  

Open Energy Info (EERE)

Perspectives GmbH Jump to: navigation, search Name Perspectives GmbH Place Hamburg, Germany Zip 22045 Product Germany-based consultancy focusing on CDMJI projects as well as GHG...

323

Biochar and Carbon Sequestration: A Regional Perspective  

E-Print Network (OSTI)

Biochar and Carbon Sequestration: A Regional Perspective A report prepared for East of England #12;Low Carbon Innovation Centre Report for EEDA Biochar and Carbon Sequestration: A Regional Perspective 20/04/2009 ii Biochar and Carbon Sequestration: A Regional Perspective A report prepared for East

Everest, Graham R

324

Atomic vapor laser isotope separation  

SciTech Connect

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

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

1985-11-08T23:59:59.000Z

325

Apparatus for storing hydrogen isotopes  

DOE Green Energy (OSTI)

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

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

1985-01-01T23:59:59.000Z

326

Isotope separation by photoselective dissociative electron capture  

DOE Patents (OSTI)

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

Stevens, C.G.

1978-08-29T23:59:59.000Z

327

Isotope separation by photoselective dissociative electron capture  

DOE Patents (OSTI)

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

Stevens, Charles G. (Pleasanton, CA)

1978-01-01T23:59:59.000Z

328

First-principles calculations of the stability and incorporation of helium, xenon and krypton in uranium  

SciTech Connect

While metallic fuels have a long history of reactor use, their fundamental physical and thermodynamic properties are not well understood. Many metallic nuclear fuels are body-centered cubic alloys of uranium that swell under fission conditions, creating fission product gases such as helium, xenon and krypton. In this paper, helium, xenon, and krypton point defects are investigated in the a and ? phases of metallic uranium using first principles calculations. A density functional theory (DFT) framework is utilized with projector augmented-wave (PAW) pseudopotentials. Formation and incorporation energies of He, Xe, and Kr are calculated at various defect positions for the prediction of fission gas behavior in uranium. In most cases, defect energies follow a size effect, with helium incorporation and formation energies being the smallest. The most likely position for the larger Xe and Kr atoms in uranium is the substitutional site. Helium atoms are likely to be found in a wide variety of defect positions due to the comparable formation energies of all defect configurations analyzed. This is the first detailed study of the stability and incorporation of fission gases in uranium.

B. Beeler; B. Good; S. Rashkeev; M. Baskes; M. Okuniewski

2012-06-01T23:59:59.000Z

329

A Concept for A Dark Matter Detector Using Liquid Helium-4  

E-Print Network (OSTI)

Direct searches for light dark matter particles (mass $<10$ GeV) are especially challenging because of the low energies transferred in elastic scattering to typical heavy nuclear targets. We investigate the possibility of using liquid Helium-4 as a target material, taking advantage of the favorable kinematic matching of the Helium nucleus to light dark matter particles. Monte Carlo simulations are performed to calculate the charge, scintillation, and triplet helium molecule signals produced by recoil He ions, for a variety of energies and electric fields. We show that excellent background rejection can be achieved based on the ratios between different signal channels. We also present some concepts for a liquid-helium-based dark matter detector. Key to the proposed approach is the use of a large electric field to extract electrons from the event site, and the amplification of this charge signal, through proportional scintillation, liquid electroluminescence, or roton emission. The sensitivity of the proposed detector to light dark matter particles is estimated for various electric fields and light collection efficiencies.

Wei Guo; Daniel N. McKinsey

2013-02-03T23:59:59.000Z

330

Helium Adsorption in Silica Aerogel near the Liquid-Vapor Critical Point  

E-Print Network (OSTI)

We have investigated the adsorption and desorption of helium near its liquid-vapor critical point in silica aerogels with porosities between 95 % and 98%. We used a capacitive measurement technique which allowed us to probe the helium density inside the aerogel directly, even though the samples were surrounded by bulk helium. The aerogel’s very low thermal conductivity resulted in long equilibration times so we monitored the pressure and the helium density, both inside the aerogel and in the surrounding bulk, and waited at each point until all had stabilized. Our measurements were made at temperatures far from the critical point, where a well defined liquid-vapor interface exists, and at temperatures up to the bulk critical point. Hysteresis between adsorption and desorption isotherms persisted to temperatures close to the liquid-vapor critical point and there was no sign of an equilibrium liquid-vapor transition once the hysteresis disappeared. Many features of our isotherms can be described in terms of capillary condensation, although this picture becomes less applicable as the liquid-vapor critical point is approached and it is unclear how it can be applied to aerogels, whose tenuous structure includes a wide range of length scales. I.

Tobias Herman; James Day; John Beamish

2008-01-01T23:59:59.000Z

331

A temperature-controlled device for volumetric measurements of Helium adsorption in porous  

E-Print Network (OSTI)

a set-up for studying adsorption of helium in silica aerogels, where the adsorbed amount is easily- dation experiments and a first application to aerogels. This device is well adapted to study hysteresis, such as grafoil, carbon nanotubes, or silica glasses. The case of silica aerogels has attracted attention

Paris-Sud XI, Université de

332

Helium adsorption in silica aerogel near the liquid-vapor critical point  

E-Print Network (OSTI)

We have investigated the adsorption and desorption of helium near its liquid-vapor critical point in silica aerogels with porosities between 95% and 98%. We used a capacitive measurement technique which allowed us to probe the helium density inside the aerogel directly, even though the samples were surrounded by bulk helium. The aerogel's very low thermal conductivity resulted in long equilibration times so we monitored the pressure and the helium density, both inside the aerogel and in the surrounding bulk, and waited at each point until all had stabilized. Our measurements were made at temperatures far from the critical point, where a well defined liquid-vapor interface exists, and at temperatures up to the bulk critical point. Hysteresis between adsorption and desorption isotherms persisted to temperatures close to the liquid-vapor critical point and there was no sign of an equilibrium liquid-vapor transition once the hysteresis disappeared. Many features of our isotherms can be described in terms of capillary condensation, although this picture becomes less applicable as the liquid-vapor critical point is approached and it is unclear how it can be applied to aerogels, whose tenuous structure includes a wide range of length scales.

Tobias Herman; James Day; John Beamish

2005-05-18T23:59:59.000Z

333

Direct evidence of mismatching effect on H emission in laser-induced atmospheric helium gas plasma  

Science Conference Proceedings (OSTI)

A time-resolved orthogonal double pulse laser-induced breakdown spectroscopy (LIBS) with helium surrounding gas is developed for the explicit demonstration of time mismatch between the passage of fast moving impurity hydrogen atoms and the formation of thermal shock wave plasma generated by the relatively slow moving major host atoms of much greater masses ablated from the same sample. Although this so-called 'mismatching effect' has been consistently shown to be responsible for the gas pressure induced intensity diminution of hydrogen emission in a number of LIBS measurements using different ambient gases, its explicit demonstration has yet to be reported. The previously reported helium assisted excitation process has made possible the use of surrounding helium gas in our experimental set-up for showing that the ablated hydrogen atoms indeed move faster than the simultaneously ablated much heavier major host atoms as signaled by the earlier H emission in the helium plasma generated by a separate laser prior to the laser ablation. This conclusion is further substantiated by the observed dominant distribution of H atoms in the forward cone-shaped target plasma.

Zener Sukra Lie; Koo Hendrik Kurniawan [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); May On Tjia [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Physics of Magnetism and Photonics Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha, Bandung 40132 (Indonesia); Rinda, Hedwig [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Suliyanti, Maria Margaretha [Research Center for Physics, Indonesia Institute of Sciences, Kawasan PUSPIPTEK, Serpong, Tangerang Selatan 15314, Banten (Indonesia); Syahrun Nur Abdulmadjid; Nasrullah Idris [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Alion Mangasi Marpaung [Department of Physics, Faculty of Mathematics and Natural Sciences, Jakarta State University, Rawamangun, Jakarta 12440 (Indonesia); Marincan Pardede [Department of Electrical Engineering, University of Pelita Harapan, 1100 M.H. Thamrin Boulevard, Lippo Village, Tangerang 15811 (Indonesia); Jobiliong, Eric [Department of Industrial Engineering, University of Pelita Harapan, 1100 M.H. Thamrin Boulevard, Lippo Village, Tangerang 15811 (Indonesia); Muliadi Ramli [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Heri Suyanto [Department of Physics, Faculty of Mathematics and Natural Sciences, Udayana University, Kampus Bukit Jimbaran, Denpasar 80361, Bali (Indonesia); Fukumoto, Kenichi; Kagawa, Kiichiro [Research Institute of Nuclear Engineering, University of Fukui, Fukui 910-8507 (Japan)

2013-02-07T23:59:59.000Z

334

Electron-impact excitation-autoionization of helium in the S-wave limit  

Science Conference Proceedings (OSTI)

Excitation of the autoionizing states of helium by electron impact is shown in calculations in the s-wave limit to leave a clear signature in the singly differential cross section for the (e,2e) process. It is suggested that such behavior should be seen generally in (e,2e) experiments on atoms that measure the single differential cross section.

Horner, Daniel A.; McCurdy, C. William; Rescigno, Thomas N.

2004-10-01T23:59:59.000Z

335

RECONCILING THE GALACTIC BULGE TURNOFF AGE DISCREPANCY WITH ENHANCED HELIUM ENRICHMENT  

SciTech Connect

We show that the factor {approx}2 discrepancy between spectroscopic and photometric age determinations of the Galactic bulge main-sequence turnoff can be naturally explained by positing an elevated helium enrichment for the bulge relative to that assumed by standard isochrones. Helium enhancement relative to standard isochrones is confirmed at the 2.3{sigma} level. We obtain an upper bound on the helium enrichment for the metal-rich ([Fe/H] Almost-Equal-To +0.30) stars of {Delta}Y Almost-Equal-To +0.11 relative to canonical expectations, given the requirement that the spectroscopic and photometric ages be consistent and the limiting condition of instantaneous star formation. We discuss phenomenological evidence that the bulge may have had a chemical evolution that is distinct from the solar neighborhood in this manner, and we make several testable predictions. Should this emerging picture of the bulge as helium-enhanced hold, it will require the development of new isochrones, new model atmospheres, and modified analysis and cosmological interpretation of the integrated light of other bulges and elliptical galaxies.

Nataf, David M.; Gould, Andrew P. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

2012-06-01T23:59:59.000Z

336

Helium, Iron and Electron Particle Transport and Energy Transport Studies on the TFTR Tokamak  

DOE R&D Accomplishments (OSTI)

Results from helium, iron, and electron transport on TFTR in L-mode and Supershot deuterium plasmas with the same toroidal field, plasma current, and neutral beam heating power are presented. They are compared to results from thermal transport analysis based on power balance. Particle diffusivities and thermal conductivities are radially hollow and larger than neoclassical values, except possibly near the magnetic axis. The ion channel dominates over the electron channel in both particle and thermal diffusion. A peaked helium profile, supported by inward convection that is stronger than predicted by neoclassical theory, is measured in the Supershot The helium profile shape is consistent with predictions from quasilinear electrostatic drift-wave theory. While the perturbative particle diffusion coefficients of all three species are similar in the Supershot, differences are found in the L-Mode. Quasilinear theory calculations of the ratios of impurity diffusivities are in good accord with measurements. Theory estimates indicate that the ion heat flux should be larger than the electron heat flux, consistent with power balance analysis. However, theoretical values of the ratio of the ion to electron heat flux can be more than a factor of three larger than experimental values. A correlation between helium diffusion and ion thermal transport is observed and has favorable implications for sustained ignition of a tokamak fusion reactor.

Synakowski, E. J.; Efthimion, P. C.; Rewoldt, G.; Stratton, B. C.; Tang, W. M.; Grek, B.; Hill, K. W.; Hulse, R. A.; Johnson, D .W.; Mansfield, D. K.; McCune, D.; Mikkelsen, D. R.; Park, H. K.; Ramsey, A. T.; Redi, M. H.; Scott, S. D.; Taylor, G.; Timberlake, J.; Zarnstorff, M. C. (Princeton Univ., NJ (United States). Plasma Physics Lab.); Kissick, M. W. (Wisconsin Univ., Madison, WI (United States))

1993-03-00T23:59:59.000Z

337

Neutron-induced dpa, transmutations, gas production, and helium embrittlement of fusion materials  

E-Print Network (OSTI)

In a fusion reactor materials will be subjected to significant fluxes of high-energy neutrons. As well as causing radiation damage, the neutrons also initiate nuclear reactions leading to changes in the chemical composition of materials (transmutation). Many of these reactions produce gases, particularly helium, which cause additional swelling and embrittlement of materials. This paper investigates, using a combination of neutron-transport and inventory calculations, the variation in displacements per atom (dpa) and helium production levels as a function of position within the high flux regions of a recent conceptual model for the "next-step" fusion device DEMO. Subsequently, the gas production rates are used to provide revised estimates, based on new density-functional-theory results, for the critical component lifetimes associated with the helium-induced grain-boundary embrittlement of materials. The revised estimates give more optimistic projections for the lifetimes of materials in a fusion power plant compared to a previous study, while at the same time indicating that helium embrittlement remains one of the most significant factors controlling the structural integrity of fusion power plant components.

M. R. Gilbert; S. L. Dudarev; D. Nguyen-Manh; S. Zheng; L. W. Packer; J. -Ch. Sublet

2013-11-20T23:59:59.000Z

338

Renewable energy perspectives in the  

E-Print Network (OSTI)

Renewable energy perspectives in the mediterranean countries - the Mediterranean Solar Plan Dr 600 800 1000 1200 1400 1990 2009 CS2030 PS2030 Mtoe Renewables & Waste Hydro Nuclear Gas Oil Coal #12 - hydro Renewables Hydro Nuclear Gas Oil Coal 2009 2030 PS2030 CS #12;RENEWABLE ELECTRICITY GENERATION 0

Canet, LĂ©onie

339

Three perspectives in formal engineering  

Science Conference Proceedings (OSTI)

We present three perspectives of the use of formalism in the construction of High-Integrity Embedded Real-time Systems. In the first, we describe the long-term research aims. The scope is the entire system, the goal is to demonstrate intentional ...

John McDermid; Andy Galloway

2006-11-01T23:59:59.000Z

340

Perspectives Computational Biology in Brazil  

E-Print Network (OSTI)

Perspectives Computational Biology in Brazil Goran Neshich Introduction At the request of the PLoS Computational Biology Editor-in- Chief, I agreed to write about computational biology in Brazil (see author of the field itself is short); b) the current state of the field in Brazil; c) the influence of computational

Neshich, Goran

Note: This page contains sample records for the topic "helium isotope perspective" 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

Tritium Isotope Separation Using Adsorption-Distillation Column  

Science Conference Proceedings (OSTI)

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

Satoshi Fukada

342

Survey of helium in soils and soil gases and mercury in soils at Roosevelt Hot Springs Known Geothermal Resource Area, Utah  

SciTech Connect

The concentrations of helium and mercury in soils and of helium in soil gases were surveyed in part of the Roosevelt Hot Springs Known Geothermal Resource Area to see what relationship helium and mercury concentrations might have to geothermal features of the area. High concentrations of helium occurred over the producing geothermal field, in an area of high temperature gradients. Low concentrations of helium in soils occurred over an area of visible hydrotheormal activity. High concentrations of mercury coincided with areas of high thermal gradients and low resistivity.

Hinkle, M.E.

1980-01-01T23:59:59.000Z

343

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

E-Print Network (OSTI)

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

Rudnick, Roberta L.

344

It's Elemental - Isotopes of the Element Boron  

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

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

345

It's Elemental - Isotopes of the Element Tungsten  

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

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

346

It's Elemental - Isotopes of the Element Carbon  

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

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

347

It's Elemental - Isotopes of the Element Rhenium  

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

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

348

Isotopically engineered semiconductors: from the bulk tonanostructures  

SciTech Connect

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

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

2006-04-07T23:59:59.000Z

349

It's Elemental - Isotopes of the Element Magnesium  

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

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

350

It's Elemental - Isotopes of the Element Chlorine  

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

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

351

It's Elemental - Isotopes of the Element Potassium  

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

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

352

It's Elemental - Isotopes of the Element Phosphorus  

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

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

353

It's Elemental - Isotopes of the Element Oxygen  

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

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

354

It's Elemental - Isotopes of the Element Gallium  

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

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

355

It's Elemental - Isotopes of the Element Sodium  

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

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

356

It's Elemental - Isotopes of the Element Neon  

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

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

357

It's Elemental - Isotopes of the Element Copper  

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

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

358

Stable isotope investigations of chlorinated aliphatic hydrocarbons.  

Science Conference Proceedings (OSTI)

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

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

1999-06-01T23:59:59.000Z

359

Atomic vapor laser isotope separation process  

DOE Patents (OSTI)

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

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

1990-08-21T23:59:59.000Z

360

It's Elemental - Isotopes of the Element Dysprosium  

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

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

Note: This page contains sample records for the topic "helium isotope perspective" 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

It's Elemental - Isotopes of the Element Antimony  

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

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

362

Improved process for preparing strontium-82 isotope  

DOE Patents (OSTI)

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

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

1991-12-31T23:59:59.000Z

363

Selective Isotope Determination of Uranium using HR-RIMS  

Science Conference Proceedings (OSTI)

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

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

2009-03-17T23:59:59.000Z

364

Isotopic evidence for the infiltration of mantle and metamorphic CO2-H2O fluids from below in faulted rocks from the San Andreas Fault System  

SciTech Connect

To characterize the origin of the fluids involved in the San Andreas Fault (SAF) system, we carried out an isotope study of exhumed faulted rocks from deformation zones, vein fillings and their hosts and the fluid inclusions associated with these materials. Samples were collected from segments along the SAF system selected to provide a depth profile from upper to lower crust. In all, 75 samples from various structures and lithologies from 13 localities were analyzed for noble gas, carbon, and oxygen isotope compositions. Fluid inclusions exhibit helium isotope ratios ({sup 3}He/{sup 4}He) of 0.1-2.5 times the ratio in air, indicating that past fluids percolating through the SAF system contained mantle helium contributions of at least 35%, similar to what has been measured in present-day ground waters associated with the fault (Kennedy et al., 1997). Calcite is the predominant vein mineral and is a common accessory mineral in deformation zones. A systematic variation of C- and O-isotope compositions of carbonates from veins, deformation zones and their hosts suggests percolation by external fluids of similar compositions and origin with the amount of fluid infiltration increasing from host rocks to vein to deformation zones. The isotopic trend observed for carbonates in veins and deformation zones follows that shown by carbonates in host limestones, marbles, and other host rocks, increasing with increasing contribution of deep metamorphic crustal volatiles. At each crustal level, the composition of the infiltrating fluids is thus buffered by deeper metamorphic sources. A negative correlation between calcite {delta}{sup 13}C and fluid inclusion {sup 3}He/{sup 4}He is consistent with a mantle origin for a fraction of the infiltrating CO{sub 2}. Noble gas and stable isotope systematics show consistent evidence for the involvement of mantle-derived fluids combined with infiltration of deep metamorphic H{sub 2}O and CO{sub 2} in faulting, supporting the involvement of deep fluids percolating through and perhaps weakening the fault zone. There is no clear evidence for a significant contribution from meteoric water, except for overprinting related to late weathering.

Pili, E.; Kennedy, B.M.; Conrad, M.E.; Gratier, J.-P.

2010-12-15T23:59:59.000Z

365

Iron isotopic fractionation during continental weathering  

SciTech Connect

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

Fantle, Matthew S.; DePaolo, Donald J.

2003-10-01T23:59:59.000Z

366

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

Science Conference Proceedings (OSTI)

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

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

2002-06-11T23:59:59.000Z

367

Final Report, NEAC Subcommittee for Isotope Research & Production Planning  

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

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

368

Plant Design and Cost Estimation of a Natural Circulation Lead-Bismuth Reactor with Helium Power Conversion Cycle  

E-Print Network (OSTI)

The analysis of an indirect helium power conversion system with lead-bismuth natural circulation primary system has been performed. The work of this report is focused on 1) identifying the allowable design region for the ...

Kim, D.

369

Time damping of non-adiabatic magnetohydrodynamic waves in a partially ionized prominence plasma: Effect of helium  

E-Print Network (OSTI)

Prominences are partially ionized, magnetized plasmas embedded in the solar corona. Damped oscillations and propagating waves are commonly observed. These oscillations have been interpreted in terms of magnetohydrodynamic (MHD) waves. Ion-neutral collisions and non-adiabatic effects (radiation losses and thermal conduction) have been proposed as damping mechanisms. We study the effect of the presence of helium on the time damping of non-adiabatic MHD waves in a plasma composed by electrons, protons, neutral hydrogen, neutral helium (He I), and singly ionized helium (He II) in the single-fluid approximation. The dispersion relation of linear non-adiabatic MHD waves in a homogeneous, unbounded, and partially ionized prominence medium is derived. The period and the damping time of Alfven, slow, fast, and thermal waves are computed. A parametric study of the ratio of the damping time to the period with respect to the helium abundance is performed. The efficiency of ion-neutral collisions as well as thermal conduc...

Soler, R; Ballester, J L

2009-01-01T23:59:59.000Z

370

Condensation of helium in aerogels as an experimental realization of the out-of-equilibrium Random Field Ising Model  

E-Print Network (OSTI)

Condensation of helium in aerogels as an experimental realization of the out-of-equilibrium Random that the condensation of 4He in base-catalysed silica aerogels of large porosity presents a similar out

Recanati, Catherine

371

Condensation of helium in aerogels as an experimental realization of the out-of-equilibrium Random Field Ising Model  

E-Print Network (OSTI)

Condensation of helium in aerogels as an experimental realization of the out-of-equilibrium Random-catalysed silica aerogels of large porosity presents a similar out-of-equilibrium behavior when the temperature

372

A Liquid-Helium-Cooled Absolute Reference Cold Load forLong-Wavelength Radiometric Calibration  

SciTech Connect

We describe a large (78-cm) diameter liquid-helium-cooled black-body absolute reference cold load for the calibration of microwave radiometers. The load provides an absolute calibration near the liquid helium (LHe) boiling point, accurate to better than 30 mK for wavelengths from 2.5 to 25 cm (12-1.2 GHz). The emission (from non-LHe temperature parts of the cold load) and reflection are small and well determined. Total corrections to the LHe boiling point temperature are {le} 50 mK over the operating range. This cold load has been used at several wavelengths at the South Pole and at the White Mountain Research Station. In operation, the average LHe loss rate was {le} 4.4 l/hr. Design considerations, radiometric and thermal performance and operational aspects are discussed. A comparison with other LHe-cooled reference loads including the predecessor of this cold load is given.

Bensadoun, M.; Witebsky, C.; Smoot, George F.; De Amici,Giovanni; Kogut, A.; Levin, S.

1990-05-01T23:59:59.000Z

373

Laser spectroscopy of the antiprotonic helium atom – its energy levels and state lifetimes  

E-Print Network (OSTI)

The antiprotonic atom is a three-body exotic system consisting of an antiproton, an electron and a helium nucleus. Its surprising longevity was found and has been studied for more than 10 years. In this work, transition energies and lifetimes of this exotic atom were systematically studied by using the antiproton beam of AD(Antiproton Decelerator) facility at CERN, with an RFQ antiproton decelerator, a narrow-bandwidth laser, Cerenkov counters with fast-response photomultiplier tubes, and cryogenic helium target systems. Thirteen transition energies were determined with precisions of better than 200 ppb by a laser spectroscopy method, together with the elimination of the shift effect caused by collisions with surrounding atoms. Fifteen lifetimes (decay rates) of short-lived states were determined from the time distributions of the antiproton-annihilation signals and the resonance widths of the atomic spectral lines. The relation between the magnitude of the decay rates and the transition multipolarity was inv...

Hidetoshi, Yamaguchi

2003-01-01T23:59:59.000Z

374

Final Technical Report for the Neutron Detection without Helium-3 Project  

SciTech Connect

This report details the results of the research and development work accomplished for the ‘Neutron Detection without Helium-3’ project conducted during the 2011-2013 fiscal years. The primary focus of the project was to investigate commercially available technologies that might be used in safeguards applications in the relatively near term. Other technologies that are being developed may be more applicable in the future, but were outside the scope of this study.

Ely, James H.; Bliss, Mary; Kouzes, Richard T.; Lintereur, Azaree T.; Robinson, Sean M.; Siciliano, Edward R.; Swinhoe, Martyn T.; Woodring, Mitchell L.

2013-11-01T23:59:59.000Z

375

Measurement of the magnetic fine structure of the 10G and 10H states of helium  

Science Conference Proceedings (OSTI)

The magnetic fine-structure intervals separating the four members of the 10G and 10H manifolds of helium have been measured with a precision of 0.1% using a fast-beam microwave-optical resonance technique. The results are found to be in good agreement with theory, illustrating that the two-electron wave function is very nearly hydrogenic. The measurements are also used to determine the small exchange energies of the 10G and 10H states.

Hessels, E.A.; Sturrus, W.G.; Lundeen, S.R.; Cok, D.R.

1987-06-01T23:59:59.000Z

376

A Simulation Study for the Virtual Commissioning of the CERN Central Helium Liquefier  

E-Print Network (OSTI)

This paper describes the implication of dynamic simulation in cryogenics processes. The simulation aims to prepare plant commissioning and operation, and to validate the efficiency of the new process control logic. PLC programs have been tested on a process simulator integrating physical models of valves, heat exchangers, turbines, phase separator, and helium data. The model has shown the capacity to reproduce cold-box dynamic behaviour, from 300 K to 4.5 K.

Rogez, E; Moraux, A; Pezzetti, M; Gayet, P; Coppier, H

2008-01-01T23:59:59.000Z

377

Modeling and Simulation Optimization and Feasibility Studies for the Neutron Detection without Helium-3 Project  

Science Conference Proceedings (OSTI)

This report details the results of the modeling and simulation work accomplished for the ‘Neutron Detection without Helium-3’ project during the 2011 and 2012 fiscal years. The primary focus of the project is to investigate commercially available technologies that might be used in safeguards applications in the relatively near term. Other technologies that are being developed may be more applicable in the future, but are outside the scope of this study.

Ely, James H.; Siciliano, Edward R.; Swinhoe, Martyn T.; Lintereur, Azaree T.

2013-01-01T23:59:59.000Z

378

SUPERBURST MODELS FOR NEUTRON STARS WITH HYDROGEN- AND HELIUM-RICH ATMOSPHERES  

SciTech Connect

Superbursts are rare day-long type I X-ray bursts due to carbon flashes on accreting neutron stars in low-mass X-ray binaries. They heat the neutron star envelope such that the burning of accreted hydrogen and helium becomes stable, and the common shorter X-ray bursts are quenched. Short bursts reappear only after the envelope cools down. We study multi-zone one-dimensional models of the neutron star envelope, in which we follow carbon burning during the superburst, and we include hydrogen and helium burning in the atmosphere above. We investigate the cases of both a solar-composition and a helium-rich atmosphere. This allows us to study for the first time a wide variety of thermonuclear burning behavior as well as the transitions between the different regimes in a self-consistent manner. For solar composition, burst quenching ends much sooner than previously expected. This is because of the complex interplay between the 3{alpha}, hot CNO, and CNO breakout reactions. Stable burning of hydrogen and helium transitions via marginally stable burning (mHz quasi-periodic oscillations) to less energetic bursts with short recurrence times. We find a short-lived bursting mode where weaker and stronger bursts alternate. Eventually the bursting behavior changes back to that of the pre-superburst bursts. Because of the scarcity of observations, this transition has not been directly detected after a superburst. Using the MINBAR burst catalog we identify the shortest upper limit on the quenching time for 4U 1636-536, and derive further constraints on the timescale on which bursts return.

Keek, L. [National Superconducting Cyclotron Laboratory, Department of Physics and Astronomy, and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Heger, A. [School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States); In 't Zand, J. J. M., E-mail: keek@nscl.msu.edu [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)

2012-06-20T23:59:59.000Z

379

Oil market in international and Norwegian perspectives.  

E-Print Network (OSTI)

??Crude oil is the most important energy source in global perspective. About 35 percent of the world’s primary energy consumption is supplied by oil, followed… (more)

Singsaas, Julia Nazyrova

2009-01-01T23:59:59.000Z

380

ANNUAL REPORT 2012 PERSPECTIVES - Sandia National Laboratories  

ANNUAL REPORT 2012 PERSPECTIVES. 2,036 Businesses Assisted ... SAND 2013-4729P Los Alamos National Laboratory Becky Coel-Roback Project Manager PO Box ...

Note: This page contains sample records for the topic "helium isotope perspective" 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

A Colorado Perspective: The New Energy Economy  

E-Print Network (OSTI)

transmission, have languished. Colorado looks forward withA Colorado Perspective: The New Energy Economy Jim Martin*REPORTING .. VIII. COLORADO'S STATE

Martin, Jim; Brannon, Ginny

2009-01-01T23:59:59.000Z

382

Factors influencing helium measurements for detection of control rod failures in BWR  

SciTech Connect

Much effort has been made to minimize the number and consequences of fuel failures at nuclear power plants. The consequences of control rod failures have also gained an increased attention. In this paper we introduce a system for on-line surveillance of control rod integrity which has several advantages comparing to the surveillance methods available today in boiling water reactors (BWRs). This system measures the helium released from failed control rods containing boron carbide (B4C). However, there are a number of factors that might influence measurements, which have to be taken into consideration when evaluating the measured data. These factors can be separated into two groups: 1) local adjustments, made on the sampling line connecting the detector to the off-gas system, and 2) plant operational parameters. The adjustments of the sample line conditions include variation of gas flow rate and gas pressure in the line. Plant operational factors that may influence helium measurements can vary from plant to plant. The factors studied at Leibstadt nuclear power plant (KKL) were helium impurities in injected hydrogen gas, variation of the total off-gas flow and regular water refill. In this paper we discuss these factors and their significance and present experimental results of measurements at KKL. (authors)

Larsson, I.; Sihver, L. [Div. of Nuclear Engineering, Dept. of Applied Physics, Chalmers Univ. of Technology, SE-412 96 Gothenburg (Sweden); Loner, H.; Ledergerber, G. [Kernkraftwerk Leibstadt, CH-5325 Leibstadt (Switzerland); Schnurr, B. [E.ON Kernkraft GmbH, D-84049 Essenbach (Germany)

2012-07-01T23:59:59.000Z

383

FLOATING PRESSURE CONVERSION AND EQUIPMENT UPGRADES OF TWO 3.5KW, 20K, HELIUM REFRIGERATORS  

SciTech Connect

Two helium refrigerators, each rated for 3.5 KW at 20 K, are used at NASA's Johnson Space Center (JSC) in Building No. 32 to provide cryogenic-pumping within two large thermal-vacuum chambers. These refrigerators were originally commissioned in 1996. New changes to the controls of these refrigerators were recently completed. This paper describes some of the control issues that necessitated the controls change-over. It will describe the modifications and the new process control which allows the refrigerators to take advantage of the Ganni Cycle “floating pressure” control technology. The controls philosophy change-over to the floating pressure control technology was the first application on a helium gas refrigeration system. Previous implementations of the floating pressure technology have been on 4 K liquefaction and refrigeration systems, which have stored liquid helium volumes that have level indications used for varying the pressure levels (charge) in the system for capacity modulation. The upgrades have greatly improved the performance, stability, and efficiency of these two refrigerators. The upgrades have also given the operators more information and details about the operational status of the main components (compressors, expanders etc.) of the refrigerators at all operating conditions (i.e. at various loads in the vacuum chambers). The performance data of the two systems, pre and post upgrading are presented.

J. Homan, V. Ganni, A. Sidi-Yekhlef, J. Creel, R. Norton, R. Linza, G. Vargas, J. Lauterbach, J. Urbin, D. Howe

2010-04-01T23:59:59.000Z

384

Determination of tritium permeation rate through T-22 in GCFR helium environment  

SciTech Connect

Measurements were made on tritium permeation rates through T-22 tubular samples in the temperature range of 300/sup 0/ to 550/sup 0/C. The tritium source consists of tritium in helium containing hydrogen at 6 vol % and sufficient water vapor to maintain a hydrogen-to-water-pressure ratio of 10, the total pressure being 1.01 x 10/sup 5/ Pa (1 atm). Two tritium sources at specific activities of 2.6 x 10/sup -3/ and 3.1 x 10/sup -2/ ..mu..Ci/std cc, respectively, were used for determining how the permeation rate varies with tritium concentration. The T-22 tubular samples have a wall thickness of 0.437 x 10/sup -2/ m (0.172 in.), and two samples are used for checking the reproducibility of the results. During the measurements, the tritium diffusing through the wall of the sample is swept out with a helium-steam mixture by bubbling helium at atmospheric pressure through a water reservoir maintained at 90/sup 0/C.

Yang, L.; Baugh, W.A.

1980-01-01T23:59:59.000Z

385

Laser Isotope Separation Employing Condensation Repression  

SciTech Connect

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

Eerkens, Jeff W.; Miller, William H.

2004-09-15T23:59:59.000Z

386

LATERALLY PROPAGATING DETONATIONS IN THIN HELIUM LAYERS ON ACCRETING WHITE DWARFS  

SciTech Connect

Theoretical work has shown that intermediate mass (0.01 M{sub Sun} < M{sub He} < 0.1 M{sub Sun }) helium shells will unstably ignite on the accreting white dwarf (WD) in an AM CVn binary. For more massive (M > 0.8 M{sub Sun }) WDs, these helium shells can be dense enough (>5 Multiplication-Sign 10{sup 5} g cm{sup -3}) that the convectively burning region runs away on a timescale comparable to the sound travel time across the shell, raising the possibility for an explosive outcome rather than an Eddington limited helium novae. The nature of the explosion (i.e., deflagration or detonation) remains ambiguous, is certainly density dependent, and likely breaks spherical symmetry. In the case of detonation, this causes a laterally propagating front whose properties in these geometrically thin and low-density shells we begin to study here. Our calculations show that the radial expansion time of <0.1 s leads to incomplete helium burning, in agreement with recent work by Sim and collaborators, but that the nuclear energy released is still adequate to realize a self-sustaining laterally propagating detonation. These detonations are slower than the Chapman-Jouguet speed of 1.5 Multiplication-Sign 10{sup 9} cm s{sup -1}, but still fast enough at 0.9 Multiplication-Sign 10{sup 9} cm s{sup -1} to go around the star prior to the transit through the star of the inwardly propagating weak shock. Our simulations resolve the subsonic region behind the reaction front in the detonation wave. The two-dimensional nucleosynthesis is shown to be consistent with a truncated one-dimensional Zeldovich-von Neumann-Doering calculation at the slower detonation speed. The ashes from the lateral detonation are typically He rich, and consist of predominantly {sup 44}Ti, {sup 48}Cr, along with a small amount of {sup 52}Fe, with very little {sup 56}Ni and with significant {sup 40}Ca in carbon-enriched layers. If this helium detonation results in a Type Ia supernova, its spectral signatures would appear for the first few days after explosion.

Townsley, Dean M. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487-0324 (United States); Moore, Kevin; Bildsten, Lars, E-mail: Dean.M.Townsley@ua.edu [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States)

2012-08-10T23:59:59.000Z

387

A Design-Builder's Perspective: Anaerobic Digestion, Forest County...  

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

A Design-Builder's Perspective: Anaerobic Digestion, Forest County Potawatomi Community - A Case Study A Design-Builder's Perspective: Anaerobic Digestion, Forest County Potawatomi...

388

Director's Perspective by George Miller | Department of Energy  

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

Perspective by George Miller Director's Perspective by George Miller Miller-LLNL-SEAB.10.11.pdf More Documents & Publications Computational Advances in Applied Energy...

389

DOE-Idaho's Packaging and Transportation Perspective | Department...  

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

and Transportation Perspective Presented by Richard Provencher, Manager for the DOE Idaho Operations Office. DOE-Idaho's Packaging and Transportation Perspective More Documents...

390

Flex power perspectives of indirect power system control through...  

Open Energy Info (EERE)

power perspectives of indirect power system control through dynamic power price (Smart Grid Project) Jump to: navigation, search Project Name Flex power perspectives of indirect...

391

The rare isotope accelerator (RIA) facility project  

DOE Green Energy (OSTI)

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

Christoph Leemann

2000-08-01T23:59:59.000Z

392

REPORT OF SURVEY OF OAK RIDGE ISOTOPE  

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

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

393

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

394

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

395

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

396

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

397

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

E-Print Network (OSTI)

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

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

2010-01-01T23:59:59.000Z

398

Laser isotope separation by multiple photon absorption  

DOE Patents (OSTI)

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

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

1977-01-01T23:59:59.000Z

399

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

400

Method for production of an isotopically enriched compound  

Science Conference Proceedings (OSTI)

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

Watrous, Matthew G.

2012-12-11T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

A user's Perspective on Software  

SciTech Connect

The user is often the most overlooked component of control system design. At Jefferson Lab the control system is almost entirely digital in nature, with little feedback except that which is deliberately designed into the control system. In the complex control room environment a good design can enhance the user's abilities to preform good science. A bad design can leave the user frustrated and contribute significantly to down time, when science is not being done. Key points of use and design from the user's perspective are discussed, along with some techniques which have been adopted at Jefferson Lab to improve the user experience and produce better, more usable software.

Isadoro T. Carlino

2006-10-24T23:59:59.000Z

402

A Utility-Affiliated Cogeneration Developer Perspective  

E-Print Network (OSTI)

This paper will address cogeneration from a utility-affiliated cogeneration developer perspective on cogeneration as it relates to the development and consumption of power available from a cogeneration project. It will also go beyond this perspective to assess likely structure of the industry in 1985 and beyond.

Ferrar, T. A.

1985-05-01T23:59:59.000Z

403

Cryogenic Adsorption of Hydrogen Isotopes over Nano-Structured Materials  

Science Conference Proceedings (OSTI)

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

X. Xiao; L. K. Heung

404

Isotope effect in BEDT-TTF based organic superconductors  

SciTech Connect

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

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

1996-10-01T23:59:59.000Z

405

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

Science Conference Proceedings (OSTI)

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

2013-03-13T23:59:59.000Z

406

Facility for Endurance Testing of Hydrophobic Isotope Exchange Catalysts  

Science Conference Proceedings (OSTI)

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

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

407

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

SciTech Connect

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

1969-02-01T23:59:59.000Z

408

Isotopic Interdiffusion Analysis and its Application in Multicomponent ...  

Science Conference Proceedings (OSTI)

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

409

Discovery of Scandium, Titanium, Mercury, and Einsteinium Isotopes  

E-Print Network (OSTI)

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

D. Meierfrankenfeld; A. Bury; M. Thoennessen

2010-03-26T23:59:59.000Z

410

Isotopic Generation and Confirmation of the PWR Application Model   

SciTech Connect

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

L.B. Wimmer

2003-11-10T23:59:59.000Z

411

Final Report on Isotope Ratio Techniques for Light Water Reactors  

SciTech Connect

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

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

2009-07-01T23:59:59.000Z

412

E.L. Grossman Chapter 10 Oxygen Isotope Stratigraphy  

E-Print Network (OSTI)

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

Grossman, Ethan L.

413

Laser Isotope Enrichment for Medical and Industrial Applications  

SciTech Connect

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

Leonard Bond

2006-07-01T23:59:59.000Z

414

A heat exchanger between forced flow helium gas at 14 to 18 K and liquid hydrogen at 20 K circulated by natural convection  

E-Print Network (OSTI)

LBNL-53719 A HEAT EXCHANGER BETWEEN FORCED FLOW HELIUM GAShydrogen absorber and the heat exchanger between the liquidpasses through the heat exchanger in the absorber shell. The

Green, M.A.; Ishimoto, S.; Lau, W.; Yang, S.

2003-01-01T23:59:59.000Z

415

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

Science Conference Proceedings (OSTI)

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

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

2008-07-01T23:59:59.000Z

416

It's Elemental - Isotopes of the Element Nitrogen  

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

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

417

RADIATION PROTECTION AND DECONTAMINATION IN ISOTOPE LABORATORIES  

SciTech Connect

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

Schanze, U.O.

1963-12-01T23:59:59.000Z

418

A passively-safe fusion reactor blanket with helium coolant and steel structure  

Science Conference Proceedings (OSTI)

Helium is attractive for use as a fusion blanket coolant for a number of reasons. It is neutronically and chemically inert, nonmagnetic, and will not change phase during any off-normal or accident condition. A significant disadvantage of helium, however, is its low density and volumetric heat capacity. This disadvantage manifests itself most clearly during undercooling accident conditions such as a loss of coolant accident (LOCA) or a loss of flow accident (LOFA). This thesis describes a new helium-cooled tritium breeding blanket concept which performs significantly better during such accidents than current designs. The proposed blanket uses reduced-activation ferritic steel as a structural material and is designed for neutron wall loads exceeding 4 MW/m{sup 2}. The proposed geometry is based on the nested-shell concept developed by Wong, but some novel features are used to reduce the severity of the first wall temperature excursion. These features include the following: (1) A ``beryllium-joint`` concept is introduced, which allows solid beryllium slabs to be used as a thermal conduction path from the first wall to the cooler portions of the blanket. The joint concept allows for significant swelling of the beryllium (10 percent or more) without developing large stresses in the blanket structure. (2) Natural circulation of the coolant in the water-cooled shield is used to maintain shield temperatures below 100 degrees C, thus maintaining a heat sink close to the blanket during the accident. This ensures the long-term passive safety of the blanket.

Crosswait, K.M.

1994-04-01T23:59:59.000Z

419

Microstructural damage produced by helium in aged /sup 238/PuO/sub 2/ fuels  

DOE Green Energy (OSTI)

Microstructural damage is produced in aged /sup 238/PuO/sub 2/ fuels used to power radioisotopic heat sources by the generation and release of the helium arising from alpha decay of the fuel. We obtained information about the nature and extent of this damage from metallographic examination of fuel pellets ranging in density from 87 to 94% with a grain size range of 6 to 30 ..mu..m that either were stored at ambient temperature for 18 months and then heated at 900, 1150, or 1360/sup 0/C or were stored at 900, 1150, or 1350/sup 0/C for 27 months. Microstructural damage was not observed in the fuel pellets stored at ambient temperature and then heated at 900/sup 0/C, but grain boundary bubble damage was observed in the pellets stored at ambient temperature and then heated at either 1150 or 1350/sup 0/C. More extensive damage occurred in those pellets heated at 1350/sup 0/C. Four of the higher density pellets (92 and 94% dense) stored at 900/sup 0/C shattered during storage and the rest appeared to be highly strained. The pellets stored at 1150/sup 0/C were damaged only slightly but were somewhat strained and appeared to have released their helium inventory only partially. All pellets stored at 1350/sup 0/C showed swelling and extensive void agglomeration. These data suggest that the best fuel operating temperature, as far as helium damage is concerned, would be approx. 1200/sup 0/C because below this temperature the fuel becomes highly strained and above this temperature the fuel swells ad becomes somewhat friable. Both these situations could adversely affect the impact behavior of the fuel from the standpoint of strength and fines generation.

Land, C.C.

1980-01-01T23:59:59.000Z

420

Theoretical study of sodium and potassium resonance lines pressure broadened by helium atoms  

SciTech Connect

We perform fully quantum mechanical calculations in the binary approximation of the emission and absorption profiles of the sodium 3s-3p and potassium 4s-4p resonance lines under the influence of a helium perturbing gas. We use carefully constructed potential energy surfaces and transition dipole moments to compute the emission and absorption coefficients at temperatures from 158 to 3000 K. Contributions from quasibound states are included. The resulting red and blue wing profiles agree well with previous theoretical calculations and with experimental measurements.

Zhu, Cheng; Babb, James F.; Dalgarno, Alex [ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)

2006-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

Theoretical study of pressure broadening of lithium resonance lines by helium atoms  

SciTech Connect

Quantum mechanical calculations are performed of the emission and absorption profiles of the lithium 2s-2p resonance line under the influence of a helium perturbing gas. We use carefully constructed potential energy surfaces and transition dipole moments to compute the emission and absorption coefficients at temperatures from 200 to 3000 K at wavelengths between 500 nm and 1000 nm. Contributions from quasibound states are included. The resulting red and blue wing profiles are compared with previous theoretical calculations and with an experiment, carried out at a temperature of 670 K.

Zhu Cheng; Babb, James F.; Dalgarno, Alex [ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)

2005-05-15T23:59:59.000Z

422

Operating experience with gas-bearing circulators in a high-pressure helium loop  

Science Conference Proceedings (OSTI)

A high-pressure engineering test loop has been designed and constructed at the Oak Ridge National Laboratory for circulating helium through a test chamber at temperatures to 1000/sup 0/C. The purpose of this loop is to determine the thermal and structural performance of proposed components for the primary loops of gas-cooled nuclear reactors. Five MW of power is available to provide the required gas temperature at the test chamber, and an air-cooled heat exchanger, rated at 4.4 MW, serves as a heat sink. This report contains results of tests performed on gas-bearing circulators.

Sanders, J.P.; Gat, Uri; Young, H.C.

1987-01-01T23:59:59.000Z

423

Low-energy scattering of antihydrogen by helium and molecular hydrogen  

SciTech Connect

In this paper, we describe in detail calculations that we have carried out of cross sections for rearrangement processes in very low-energy helium+antihydrogen (H-bar) scattering that result in He{sup +}p-bar+Ps or Hep-bar+e{sup +} or {alpha}p-bar+Ps{sup -}. The interaction between the leptons is taken into account very accurately. Results are presented for all three processes. A description is also given of a preliminary calculation of elastic and antiproton annihilation cross sections for very low-energy H{sub 2}+H-bar scattering.

Armour, E. A. G.; Todd, A. C.; Liu, Y.; Gregory, M. R. [School of Mathematical Sciences, Nottingham University, Nottingham NG7 2RD (United Kingdom); Jonsell, S. [Department of Physics, University of Wales Swansea, Swansea SA2 8PP (United Kingdom); Plummer, M. [CLRC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom)

2008-08-08T23:59:59.000Z

424

Ultracold neutron accumulation in a superfluid-helium converter with magnetic multipole reflector  

E-Print Network (OSTI)

We analyze accumulation of ultracold neutrons (UCN) in a superfluid-helium converter vessel surrounded by a magnetic multipole reflector. Employing formulas valid for trapped UCN in mechanical equilibrium we solved the rate equation and obtained results for the saturation density of low field seeking UCN for any field strength of the multipolar field. The addition of magnetic storage can increase the density and energy of the UCN produced and serves to mitigate the effects of wall losses on the source performance. This work was performed in preparation of the UCN source project SuperSUN at the ILL.

O. Zimmer; R. Golub

2013-03-08T23:59:59.000Z

425

Deep Burn Develpment of Transuranic Fuel for High-Temperature Helium-Cooled Reactors - July 2010  

SciTech Connect

The DB Program Quarterly Progress Report for April - June 2010, ORNL/TM/2010/140, was distributed to program participants on August 4. This report discusses the following: (1) TRU (transuranic elements) HTR (high temperature helium-cooled reactor) Fuel Modeling - (a) Thermochemical Modeling, (b) 5.3 Radiation Damage and Properties; (2) TRU HTR Fuel Qualification - (a) TRU Kernel Development, (b) Coating Development, (c) ZrC Properties and Handbook; and (3) HTR Fuel Recycle - (a) Recycle Processes, (b) Graphite Recycle, (c) Pyrochemical Reprocessing - METROX (metal recovery from oxide fuel) Process Development.

Snead, Lance Lewis [ORNL; Besmann, Theodore M [ORNL; Collins, Emory D [ORNL; Bell, Gary L [ORNL

2010-08-01T23:59:59.000Z

426

Decoding sequential vs non-sequential two-photon double ionizationof helium using nuclear recoil  

SciTech Connect

Above 54.4 eV, two-photon double ionization of helium isdominated by a sequential absorption process, producing characteristicbehavior in the single and triple differential cross sections. We showthat the signature of this process is visible in the nuclear recoil crosssection, integrated over all energy sharings of the ejected electrons,even below the threshold for the sequential process. Since nuclear recoilmomentum imaging does not require coincident photoelectron measurement,the predicted images present a viable target for future experiments withnew short-pulse VUV and soft X-ray sources.

Horner, Daniel A.; Rescigno, Thomas N.; McCurdy, C. William

2008-01-07T23:59:59.000Z

427

Triple Differential Cross sections and Nuclear Recoil in Two-Photon Double Ionization of Helium  

SciTech Connect

Triple differential cross sections (TDCS) for two-photon double ionization of helium are calculated using the method of exterior complex scaling both above and below the threshold for sequential ionization (54.4 eV). It is found that sequential ionization produces characteristic behavior in the TDCS that identifies that process when it is in competition with nonsequential ionization. Moreover we see the signature in the TDCS and nuclear recoil cross sections of"virtual sequential ionization" below the threshold for the sequential process.

Horner, Daniel A.; McCurdy, C. William; Rescigno, Thomas N

2008-04-29T23:59:59.000Z

428

Main features of direct cycle helium gas turbines integrated with a high temperature reactor  

SciTech Connect

From international nuclear industries fair; Basel, Switzerland (16 Oct 1972). The main features and advantages of direct cycle helium gas turbines integrated with a high temperature reactor are presented. The proposed design concept is based on a logical extension of existirg knowledge and experience on currently built gas cooled reactors and industrial gas turbines. The direct cycle gas turbine offers many advantages in the form of high reliability, safety and simplicity; it emerges as a potential competitor to the main power generation prime mover, the steam turbine. (auth)

Burylo, P.

1972-01-01T23:59:59.000Z

429

Cryogenic design of the liquid helium experiment ``critical dynamics in microgravity``  

Science Conference Proceedings (OSTI)

Although many well controlled experiments have been conducted to measure the static properties of systems near criticality, few experiments have explored the transport properties in systems driven far away from equilibrium as a phase transition occurs. The cryogenic design of an experiment to study the dynamic aspect of critical phenomena is reported here. Measurements of the thermal gradient across the superfluid (He II) -- normal fluid (He I) interface in helium under microgravity conditions will be performed as a heat flux holds the system away from equilibrium. New technologies are under development for this experiment, which is in the definition phase for a space shuttle flight.

Moeur, W.A. [New Mexico Univ., Albuquerque, NM (United States); Adriaans, M.J.; Boyd, S.T. [Sandia National Labs., Albuquerque, NM (United States); Strayer, D.M. [Jet Propulsion Lab., Pasadena, CA (United States); Duncan, R.V. [New Mexico Univ., Albuquerque, NM (United States)]|[Sandia National Labs., Albuquerque, NM (United States)

1995-10-01T23:59:59.000Z

430

A helium-cooled blanket design of the low aspect ratio reactor  

Science Conference Proceedings (OSTI)

An aggressive low aspect ratio scoping fusion reactor design indicated that a 2 GW(e) reactor can have a major radius as small as 2.9 m resulting in a device with competitive cost of electricity at 49 mill/kWh. One of the technology requirements of this design is a high performance high power density first wall and blanket system. A 15 MPa helium-cooled, V-alloy and stagnant LiPb breeder first wall and blanket design was utilized. Due to the low solubility of tritium in LiPb, there is the concern of tritium migration and the formation of V-hydride. To address these issues, a lithium breeder system with high solubility of tritium has been evaluated. Due to the reduction of blanket energy multiplication to 1.2, to maintain a plant Q of > 4, the major radius of the reactor has to be increased to 3.05 m. The inlet helium coolant temperature is raised to 436 C in order to meet the minimum V-alloy temperature limit everywhere in the first wall and blanket system. To enhance the first wall heat transfer, a swirl tape coolant channel design is used. The corresponding increase in friction factor is also taken into consideration. To reduce the coolant system pressure drop, the helium pressure is increased from 15 to 18 MPa. Thermal structural analysis is performed for a simple tube design. With an inside tube diameter of 1 cm and a wall thickness of 1.5 mm, the lithium breeder can remove an average heat flux and neutron wall loading of 2 and 8 MW/m(2), respectively. This reference design can meet all the temperature and material structural design limits, as well as the coolant velocity limits. Maintaining an outlet coolant temperature of 650 C, one can expect a gross closed cycle gas turbine thermal efficiency of 45%. This study further supports the use of helium coolant for high power density reactor design. When used with the low aspect ratio reactor concept a competitive fusion reactor can be projected at 51.9 mill/kWh.

Wong, C.P.; Baxi, C.B.; Reis, E.E. [General Atomics, San Diego, CA (United States); Cerbone, R.; Cheng, E.T. [TSI Research, Solana Beach, CA (United States)

1998-03-01T23:59:59.000Z

431

Primordial Helium Abundance from CMB: a constraint from recent observations and a forecast  

E-Print Network (OSTI)

We study a constraint on the primordial helium abundance $Y_p$ from current and future observations of CMB. Using the currently available data from WMAP, ACBAR, CBI and BOOMERANG, we obtained the constraint as $Y_p = 0.25 \\pm 0.10$ at 1$\\sigma$ level. We also provide a forecast for Planck using the Markov Chain Monte Carlo approach. In addition to forecasting the constraint on $Y_p$, we investigate how assumptions for $Y_p$ affect the constraints on the other cosmological parameters.

Ichikawa, Kazuhide; Takahashi, Tomo

2007-01-01T23:59:59.000Z

432

Primordial Helium Abundance from CMB: a constraint from recent observations and a forecast  

E-Print Network (OSTI)

We studied a constraint on the primordial helium abundance Y_p from current and future observations of CMB. Using the currently available data from WMAP, ACBAR, CBI and BOOMERANG, we obtained the constraint as Y_p = 0.25^{+0.10}_{-0.07} at 68% C.L. We also provide a forecast for the Planck experiment using the Markov chain Monte Carlo approach. In addition to forecasting the constraint on Y_p, we investigate how assumptions for Y_p affect constraints on the other cosmological parameters.

Kazuhide Ichikawa; Toyokazu Sekiguchi; Tomo Takahashi

2007-12-28T23:59:59.000Z

433

High-energy electron-helium scattering in a Nd:YAG laser field  

SciTech Connect

We report measurements of the scattering of electrons by helium atoms in the presence of 1.17 eV photons from a Nd:YAG laser. The incident energy of the electrons was in the range 50-350 eV, and the polarization of the laser was arranged to be parallel to electrons scattered through 135 deg. Energy-shifted peaks corresponding both to one- and two-photon emission were observed. Calculations using the Kroll-Watson approximation are perfectly consistent with the data.

Harak, B. A. de [Physics Department, Illinois Wesleyan University, P.O. Box 2900, Bloomington, Illinois 61702-2900 (United States); Ladino, L.; MacAdam, K. B.; Martin, N. L. S. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 (United States)

2011-02-15T23:59:59.000Z

434

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

435

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

436

Perspective for Female Medical Physicists  

Science Conference Proceedings (OSTI)

Due to cultural and religious reasons, Pakistani women can be reluctant to seek medical attention for disorders affecting their genitals or breasts. As a result, in the case of cervical and breast cancers, oncological treatment is often not received until the diseases are in the late stages. Once a cancer is classified and the tumor marked, the role of the medical physicist begins. Medical physicists' responsibilities include treatment planning, supervising treatment through radiation, dosimetry, contouring, training, equipment selection, education, research, and supervising radiotherapy facilities. In brachytherapy, isotopes are placed at the tumor site in the form of wires or seeds. There are very few female medical physicists in Pakistan. This leads to further hesitation on the part of many women to seek treatment. To help female patients obtain needed medical care, female physics students should be encouraged to pursue the emerging field of medical physics. This would provide a new professional opportunity for female physics students and give comfort to female patients.

Naqvi, Syed Mansoor [Department of Radiology, Aga Khan University Hospital, Karachi (Pakistan); Hasnain, Aziz Fatima [Center for Physics Education, Karachi (Pakistan)

2009-04-19T23:59:59.000Z

437

Board Staff Perspectives Quality Council  

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

Nuclear Facilities Safety Nuclear Facilities Safety Board Th B d & T h i l S ff Q li A The Board & Technical Staff Quality Assurance Perspectives for 2011 2010 Dr. W. San Horton, PMP, CSQE Member of the Technical Staff Defense Nuclear Facilities Safety Board DISCLAIMER The ie s and opinions presented are solel the a thor's No information contained in the presentation nor an associated The views and opinions presented are solely the author's. No information contained in the presentation nor any associated discussion should be construed as official or unofficial views or positions of the Defense Nuclear Facilities Safety Board Defense Nuclear Facilities Safety Board T i Topics B i I f ti B d * Basic Information on Board * Who, what, mission, size, location * Organization of the Board and the Board's staff

438

Word Pro - Perspectives.lwp  

Gasoline and Diesel Fuel Update (EIA)

2 2 xvii Energy Perspectives 18.97 in 1970 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 0 30 60 90 120 Quadrillion Btu Figure 1. Energy Overview The United States was self-sufficient in energy until the late 1950s when energy consumption began to outpace domestic production. The Nation imported more energy to fill the gap. In 2002, net imported energy accounted for 26 percent of all energy consumed. Figure 1. Energy Overview Overview Exports Production Imports Consumption 1950 1960 1970 1980 1990 2000 0 5 10 15 20 25 per Chained (1996) Dollar Thousand Btu Figure 3. Energy Use per Dollar of Gross Domestic Product Over the second half of the 20th century, the rate at which energy was consumed per dollar of the economy's output of goods and services fell dramatically. By the end of the century, the rate was half of the mid-century

439

Word Pro - Perspectives.lwp  

Gasoline and Diesel Fuel Update (EIA)

7 7 xix Energy Perspectives 18.97 in 1970 1950 1960 1970 1980 1990 2000 0 20 40 60 80 100 120 Quadrillion Btu The United States was self-sufficient in energy until the late 1950s when energy consumption began to outpace domestic production. At that point, the Nation began to import more energy to fill the gap. In 2007, net imported energy accounted for 29 percent of all energy consumed. Figure 1. Primary Energy Overview Overview Exports Production Imports Consumption 1950 1960 1970 1980 1990 2000 0 5 10 15 20 25 Thousand Btu per Chained (2000) Dolla Figure 3. Energy Use per Dollar of Gross Domestic Product After 1970, the amount of energy consumed to produce a dollar's worth of the Nation's output of goods and services trended down. The decline resulted from efficiency improvements and structural changes in the econ-

440

Word Pro - Perspectives.lwp  

Gasoline and Diesel Fuel Update (EIA)

Annual Energy Review 2009 Annual Energy Review 2009 xix 1950 1960 1970 1980 1990 2000 0 20 40 60 80 100 120 Quadrillion Btu The United States was self-sufficient in energy until the late 1950s when energy consumption began to outpace domestic production. At that point, the Nation began to import more energy to meet its needs. In 2009, net imported energy accounted for 24 percent of all energy consumed. Figure 1. Primary Energy Overview Energy Perspectives Overview Exports Production Imports Consumption 1950 1960 1970 1980 1990 2000 0 5 10 15 20 25 Thousand Btu per Chained (2005) Dolla Figure 3. Energy Use per Dollar of Gross Domestic Product After 1970, the amount of energy consumed to produce a dollar's worth of the Nation's output of goods and services trended down. The decline resulted from efficiency improvements and structural changes in the econ-

Note: This page contains sample records for the topic "helium isotope perspective" 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

Word Pro - Perspectives.lwp  

Gasoline and Diesel Fuel Update (EIA)

6 6 xix Energy Perspectives 18.97 in 1970 1950 1960 1970 1980 1990 2000 0 20 40 60 80 100 120 Quadrillion Btu The United States was self-sufficient in energy until the late 1950s when energy consumption began to outpace domestic production. At that point, the Nation began to import more energy to fill the gap. In 2006, net imported energy accounted for 30 percent of all energy consumed. Figure 1. Energy Overview Overview Exports Production Imports Consumption 1950 1960 1970 1980 1990 2000 0 5 10 15 20 25 Thousand Btu per Chained (2000) Dolla Figure 3. Energy Use per Dollar of Gross Domestic Product After 1970, the amount of energy consumed to produce a dollar's worth of the Nation's output of goods and services trended down. The decline resulted from efficiency improvements and structural changes in the econ-

442

Liquid helium and liquid neon-sensitive, low background scintillation media for the detection of low energy neutrinos  

SciTech Connect

The use of liquid helium and neon as scintillators for neutrino detection is investigated. Several unique properties of these cryogens make them promising candidates for real-time solar neutrino spectroscopy: large ultraviolet scintillation yields from ionizing radiation, transparency to their own scintillation light, and low levels of radioactive impurities. When neutrinos scatter from electrons in liquid helium or neon, ultraviolet light is emitted. The ultraviolet scintillation light can be efficiently converted to the visible with wavelength shifting films. In this way the neutrino-electron scattering events can be detected by photomultiplier tubes at room temperature. The authors conclude that the solar neutrino flux from the p + p {yields} e{sup +} + d + {nu}{sub e} reaction could be characterized and monitored versus time using a 10 ton mass of liquid helium or neon as a scintillation target.

McKinsey, D.N.; Doyle, J.M.

2000-02-01T23:59:59.000Z

443

Ultrafast probing of ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets  

SciTech Connect

The ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets are studied with time-resolved extreme ultraviolet ion imaging spectroscopy. At excitation energies of 23.6 {+-} 0.2 eV, Rydberg atoms in n= 3 and n= 4 states are ejected on different time scales and with significantly different kinetic energy distributions. Specifically, n= 3 Rydberg atoms are ejected with kinetic energies as high as 0.85 eV, but their appearance is delayed by approximately 200 fs. In contrast, n= 4 Rydberg atoms appear within the time resolution of the experiment with considerably lower kinetic energies. Major features in the Rydberg atom kinetic energy distributions for both principal quantum numbers can be described within a simple elastic scattering model of localized perturbed atomic Rydberg atoms that are expelled from the droplet due to their repulsive interaction with the surrounding helium bath. Time-dependent kinetic energy distributions of He{sub 2}{sup +} and He{sub 3}{sup +} ions are presented that support the formation of molecular ions in an indirect droplet ionization process and the ejection of neutral Rydberg dimers on a similar time scale as the n= 3 Rydberg atoms.

Buenermann, Oliver; Kornilov, Oleg; Neumark, Daniel M. [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry, University of California, Berkeley, California 94720 (United States); Haxton, Daniel J.; Gessner, Oliver [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Leone, Stephen R. [Ultrafast X-ray Science Laboratory, Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Chemistry, University of California, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States)

2012-12-07T23:59:59.000Z

444

Helium and hydrogen measurements on pure materials irradiated in SINQ Target 4  

Science Conference Proceedings (OSTI)

Several irradiations have been performed in the Swiss Spallation Neutron Source (SINQ) to establish a materials database for mixed proton and neutron fluxes for future spallation neutron and other accelerator sources. Pure metal dosimetry materials from the second irradiation (STIP-II) have been analyzed for their total helium and hydrogen contents and their release characteristics with temperature (TDS). Total helium results are similar to those observed earlier from the first irradiation experiment (STIP-I), with concentrations ranging from ~500 to ~1,000 appm. Hydrogen contents varied over a larger range from ~100 to ~60,000 (for Ti, Nb, and Ta). 3He/4He ratios were generally consistent with expectations, except for Ti, Nb, and Ta which showed lower values due to 3He from decay of irradiation-generated tritium. Some differences were observed in the hydrogen TDS data for the control and irradiated materials, including some evidence for additional lower-temperature release and for multiple release peaks. Additionally, differences were noted in the releases for irradiated material that been cleaned versus material that had no cleaning.

Oliver, Brian M.; Dai, Yong

2009-04-30T23:59:59.000Z

445

Quantum entanglement for two electrons in the excited states of helium-like systems  

E-Print Network (OSTI)

The quantum entanglement for the two electrons in the excited states of the helium-like atom/ions is investigated using the two-electron wave functions constructed by the B-spline basis. As a measure of the spatial (electron-electron orbital) entanglement, the von Neumann entropy and linear entropy of the reduced density matrix are calculated for the 1s2s 1,3S excited states for systems with some selected Z values from Z=2 to Z=100. Results for the helium atom are compared with other available calculations. We have also investigated the entropies for these excited states when the nucleus charge is reduced from Z=2 to Z=1. At such a critical charge, all the singly-excited states of this system become unbound, and the linear entropies and the von Neumann entropies for the excited states are approaching 1/2 and 1, respectively, the limits for the entropies when one electron is bound to the nucleus, and the other being free.

Yen-Chang Lin; Yew Kam Ho

2013-07-21T23:59:59.000Z

446

Quantum entanglement for two electrons in the excited states of helium-like systems  

E-Print Network (OSTI)

The quantum entanglement for the two electrons in the excited states of the helium-like atom/ions is investigated using the two-electron wave functions constructed by the B-spline basis. As a measure of the spatial (electron-electron orbital) entanglement, the von Neumann entropy and linear entropy of the reduced density matrix are calculated for the 1s2s 1,3S excited states for systems with some selected Z values from Z=2 to Z=100. Results for the helium atom are compared with other available calculations. We have also investigated the entropies for these excited states when the nucleus charge is reduced from Z=2 to Z=1. At such a critical charge, all the singly-excited states of this system become unbound, and the linear entropies and the von Neumann entropies for the excited states are approaching 1/2 and 1, respectively, the limits for the entropies when one electron is bound to the nucleus, and the other being free.

Lin, Yen-Chang

2013-01-01T23:59:59.000Z

447

OPTIMAL DESIGN AND OPERATION OF HELIUM REFRIGERATION SYSTEMS USING THE GANNI CYCLE  

SciTech Connect

The constant pressure ratio process, as implemented in the floating pressure - Ganni cycle, is a new variation to prior cryogenic refrigeration and liquefaction cycle designs that allows for optimal operation and design of helium refrigeration systems. This cycle is based upon the traditional equipment used for helium refrigeration system designs, i.e., constant volume displacement compression and critical flow expansion devices. It takes advantage of the fact that for a given load, the expander sets the compressor discharge pressure and the compressor sets its own suction pressure. This cycle not only provides an essentially constant system Carnot efficiency over a wide load range, but invalidates the traditional philosophy that the (‘TS’) design condition is the optimal operating condition for a given load using the as-built hardware. As such, the Floating Pressure- Ganni Cycle is a solution to reduce the energy consumption while increasing the reliability, flexibility and stability of these systems over a wide operating range and different operating modes and is applicable to most of the existing plants. This paper explains the basic theory behind this cycle operation and contrasts it to the traditional operational philosophies presently used.

Venkatarao Ganni, Peter Knudsen

2010-04-01T23:59:59.000Z

448

Relations between light emission and electron density and temperature fluctuations in a helium plasma  

Science Conference Proceedings (OSTI)

The relations between three atomic lines, He I 667.8 nm (3{sup 1}D{yields} 2{sup 1}P), 706.5 nm (3{sup 3}S{yields} 2{sup 3}P), and 728.1 nm (3{sup 1}S{yields} 2{sup 1}P), and the underlying fluctuations in a helium plasma are investigated for the quantitative interpretation of optical observations in plasma fluctuation measurements. Frequency dependent fluctuation amplitude ratios and phase delays between the line emission fluctuation and the electron density and temperature fluctuations are calculated based on a quasi-static collisional-radiative model and a linear approximation technique. For frequencies up to the upper limit of practical interest (<1 MHz), the fluctuation amplitude ratios and phase delays are similar to those directly evaluated by the quasi-static model. It is found that the difference between the results from the linear approximation technique and from the quasi-static model is due to the absence of metastable fluctuations. Contributions of the 2{sup 1}S and 2{sup 3}S metastable fluctuations to the three helium line emission fluctuations are analyzed. The linearity between fluctuations in the line emission and in the electron density and temperature is valid for fluctuation levels higher than 10%.

Ma Shuiliang; Howard, John; Thapar, Nandika [Plasma Research Laboratory, Australian National University, Canberra ACT 0200 (Australia)

2011-08-15T23:59:59.000Z

449

Stability of the bituminous coal microstructure upon exposure to high pressures of helium  

Science Conference Proceedings (OSTI)

Small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) measurements of the structure of two Australian bituminous coals (particle size of 1-0.5 mm) before, during, and after exposure to 155 bar of helium were made to identify any effects of pressure alone on the pore size distribution of coal and any irreversible effects upon exposure to high pressures of helium in the pore size range from 3 nm to 10 {mu}m. No irreversible effects upon exposure were identified for any pore size. No effects of pressure on pore size distribution were observed, except for a small effect at a pore size of about 2 {mu}m for one coal. This study provides a convenient baseline for SANS and USANS investigations on sorption of gases at elevated pressures on coals, by distinguishing between the effect of pressure alone on coal pore size distribution and against the effect of the gas to be investigated. 35 refs., 5 figs., 1 tab.

Richard Sakurovs; Andrzej P. Radliski; Yuri B. Melnichenko; Tomas Blach; Gang Cheng; Hartmut Lemmel; Helmut Rauch [CSIRO Energy Technology, Newcastle, NSW (Australia)

2009-09-15T23:59:59.000Z

450

There is no explosion risk associated with superfluid Helium in the LHC cooling system  

E-Print Network (OSTI)

We evaluate speculation about the possibility of a dangerous release of energy within the liquid Helium of the Large Hadron Collider (LHC) cryogenic system due to the occurrence of a "Bose-Nova". Bose-Novae are radial bursts of rapidly moving atoms which can occur when a Bose-Einstein Condensate (BEC) undergoes a collapse due the interatomic potential being deliberately made attractive using a magnetic field close to the Feshbach resonance. Liquid 4He has a monatomic structure with s-wave electrons, zero nuclear spin, no hyperfine splitting, and as a consequence no Feshbach resonance which would allow one to change its normally repulsive interactions to be attractive. Because of this, a Bose-Nova style collapse of 4He is impossible. Additional speculations concerning cold fusion during these events are easily dismissed using the usual arguments about the Coulomb barrier at low temperatures, and are not needed to explain the Bose-Einstein condensate Bose-Nova phenomenon. We conclude that that there is no physics whatsoever which suggests that Helium could undergo any kind of unforeseen catastrophic explosion.

Malcolm Fairbairn; Bob McElrath

2008-09-23T23:59:59.000Z

451

The Heat Loss Analysis and Commissioning of a Commercial Helium Dewar (SULI paper)  

SciTech Connect

A low temperature cryostat suitable for many different experiments will be commissioned at the cryogenic test facility at SLAC. The scope of the project is to make commission a commercial Helium dewar. The building of the top flange will be followed from its design phase through to its finished assembly. In addition, diagnostic tools such as thermometry, level detector, pressure gauge, transfer lines for He and N2, vent lines with relief valves for He and N2 will be incorporated. Instrumentation to read and plot this data will also be included. Once the cryostat is assembled, we will cool down the cryostat to measure its performance. A typical consumption rate of Helium will be measured and from this, the overall heat leak to the dewar will be calculated. A processing instrumentation diagram (PID) of the dewar system was created with SolidEdge and was later approved and published as an official SLAC document. The plots comparing the liquid level changes of the 36 inch probe with the time and the heat loss as a function of time proved to be a valid indication that the data was interpreted and recorded correctly and that the dewar was put together successfully.

Bellamy, Marcus; /New Mexico U. /SLAC

2006-01-04T23:59:59.000Z

452

The Local Helium Compound Transfer Lines for the Large Hadron Collider Cryogenic System  

E-Print Network (OSTI)

The cryogenic system for the Large Hadron Collider (LHC) under construction at CERN will include twelve new local helium transfer lines distributed among five LHC points in underground caverns. These lines, being manufactured and installed by industry, will connect the cold boxes of the 4.5-K refrigerators and the 1.8-K refrigeration units to the cryogenic interconnection boxes. The lines have a maximum of 30-m length and may possess either small or large re-distribution units to allow connection to the interface ports. Due to space restrictions the lines may have complex routings and require several elbowed sections. The lines consist of a vacuum jacket, a thermal shield and either three or four helium process pipes. Specific internal and external supporting and compensation systems were designed for each line to allow for thermal contraction of the process pipes (or vacuum jacket, in case of a break in the insulation vacuum) and to minimise the forces applied to the interface equipment. Whenever possible, f...

Parente, C; Munday, A; Wiggins, P

2006-01-01T23:59:59.000Z

453

^9-W-9o-^ PERMEATION OF HELIUM THROUGH SCHOTT 8246 GLASS  

E-Print Network (OSTI)

Permeation of He from the atmosphere through the glass or quartz envelopes of photomultipliers is a threat to their longevity. Helium occurs naturally at the level of 5 ppm in the atmosphere, and can be much higher in laboratories that handle liquid He, or where natural gas is used as a fuel. Helium causes afterpulsing in photomultipliers. (at least) two papers that discuss it1’2. There are Because the permeation characteristics of Schott 8246 were not known, Los Alamos contracted with Jeff Kohli at the New York State College of Ceramics to measure it. The method used is mentioned in his letter, and described in more detail in Ref. 3. It is fairly straightforward, and the same method we are using at Los Alamos to study permeabilities of other materials. Kohli’s data shows that 8246 is actually quite good from the standpoint of resisting permeation by He. As it appears to be better than any other glass commonly used for photomultipliers (see attached Figure), we have not attempted to make a detailed interpretation in terms of afterpulsing. If other glasses are acceptable, Schott 8246 should be more so. The physical reason for this good performance is understood in terms of the presence of relatively heavy cations in the 8246 glass matrix (proprietary ingredient). These tend to block otherwise open channels. We conclude that Schott 8246 should be entirely satisfactory from the He permeation standpoint and that no special precautions (other than protection from high He concentrations) will be required.

R. G. H. Robertson; Jeff Kohli

1990-01-01T23:59:59.000Z

454

Experimental confirmation of photon-induced spin-flip transitions in helium via triplet metastable yield spectra  

SciTech Connect

Doubly excited states below the N=2 ionization threshold are populated by exciting helium atoms in a supersonic beam with monochromatized synchrotron radiation. The fluorescence decay of these states triggers a radiative cascade back to the ground state with large probability to populate long lived singlet and triplet helium metastable states. The yield of metastables is measured using a multichannel plate detector after the beam has passed a singlet-quenching discharge lamp. The variation of the yield observed with the lamp switched on or off is related to the triplet-singlet mixing of the doubly excited states.

Rubensson, Jan-Erik [Department of Physics and Astronomy, Box 530, S-75121 Uppsala (Sweden); Moise, Angelica; Richter, Robert [Sincrotrone Trieste, in Area Science Park, I-34149 Basovizza, Trieste (Italy); Mihelic, Andrej; Bucar, Klemen; Zitnik, Matjaz [Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia)

2010-06-15T23:59:59.000Z

455

Commissioning and Operational Experience with 1 kW Class Helium Refrigerator/Liquefier for SST?1  

Science Conference Proceedings (OSTI)

The helium refrigerator/liquefier (R/L) for the Steady State Super conducting Tokamak (SST?1) has been developed with very stringent specifications for the different operational modes. The total refrigeration capacity is 650 W at 4.5 K and liquefaction capacity of 200 l/h. A cold circulation pump is used for the forced flow cooling of 300 g/s supercritical helium (SHe) for the magnet system (SCMS). The R/L has been designed also to absorb a 200 W transient heat load of the SCMS. The plant consists of a compressor station

C. P. Dhard; B. Sarkar; Ruchi Misra; A. K. Sahu; V. L. Tanna; J. Tank; P. Panchal; J. C. Patel; G. D. Phadke; Y. C. Saxena

2004-01-01T23:59:59.000Z

456

Continued studies of co-pumping of deuterium and helium on a single, 4K activated charcoal panel  

SciTech Connect

The short program undertaken in 1989 to evaluate the feasibility of co-pumping deuterium and tritium (DT) and helium on a charcoal sorbent showed that the charcoal will indeed simultaneously pump the gases. Of interest also was the fact that the total accumulation of helium (capacity) was virtually identical in constant throughput runs in which the D{sub 2}/He ratio was changed between runs. The test program described in this paper undertaken to evaluate further the co-pumping capabilities of the charcoal sorbent.

Walthers, C.R.; Jenkins, E.M. (Los Alamos National Lab., NM (USA)); Batzer, T.H. (Lawrence Livermore National Lab., CA (USA)); Sedgley, D.W. (Grumman Aerospace Corp., Bethpage, NY (USA)); Konishi, S.; Ohira, S.; Naruse, Y. (Japan Atomic Energy Research Inst., Tokyo (Japan))

1990-09-01T23:59:59.000Z

457

A technology perspective on worldwide privacy regulations  

Science Conference Proceedings (OSTI)

In this paper we provide an overview of the worldwide privacy regulatory landscape from a technology perspective. We focus on data-centric definitions of personal information and then examine how these differ across different regulatory frameworks, such ...

D. A. Chapin; A. C. Nelson; B. S. Gerber

2009-03-01T23:59:59.000Z

458

The 1986 Southeast Drought in Historical Perspective  

Science Conference Proceedings (OSTI)

The dry and hat weather in the southeast United States during the first seven months of 1986 caused record drought. The agricultural and hydrological perspectives of this drought are examined via a climatological time series. Late nineteenth and ...

Thomas R. Karl; Pamela J. Young

1987-07-01T23:59:59.000Z

459

Solar energy perspectives for public power  

DOE Green Energy (OSTI)

Perspectives on the utilization of solar energy for electricity production and thermal energy utilization by the public are briefly discussed. Wind energy conversion, biomass conversion, solar thermal, OTEC, photovoltaics, and solar heating and cooling are discussed. (WHK)

Woodley, N. H.

1979-06-01T23:59:59.000Z

460

A Nonlinear Dynamical Perspective on Climate Prediction  

Science Conference Proceedings (OSTI)

A nonlinear dynamical perspective on climate prediction is outlined, based on a treatment of climate as the attractor of a nonlinear dynamical system D with distinct quasi-stationary regimes. The main application is toward anthropogenic climate ...

T. N. Palmer

1999-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "helium isotope perspective" 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

A Surface Energy Perspective on Climate Change  

Science Conference Proceedings (OSTI)

A surface forcing response framework is developed that enables an understanding of time-dependent climate change from a surface energy perspective. The framework allows the separation of fast responses that are unassociated with global-mean ...

Timothy Andrews; Piers M. Forster; Jonathan M. Gregory

2009-05-01T23:59:59.000Z

462

LLNL-PRES-463228 FUSION PERSPECTIVES*  

E-Print Network (OSTI)

LLNL-PRES-463228 FUSION PERSPECTIVES* LLNL Fusion Energy Sciences Program D.D. Ryutov Fusion, Novosibirsk, July 1988: working together with the LLNL team #12;Axisymmetric mirrors can serve as a basis

463

Obtaining polarized liquid helium 3 from optically oriented gas G. Tastevin, P.J. Nacher, L. Wiesenfeld*, M. Leduc and F. Lalo  

E-Print Network (OSTI)

1 Obtaining polarized liquid helium 3 from optically oriented gas G. Tastevin, P.J. Nacher, L liquid helium three can be obtained by liquefaction of a gas polarized by laser optical pumping. We show of the system, for example liquid gas transition di- agrams [4,5]. Studying this class of effects re- quires

Paris-Sud XI, Université de

464

Spent Nuclear Fuel (SNF) Project Cask and MCO Helium Purge System Design Review Completion Report Project A.5 and A.6  

SciTech Connect

This report documents the results of the design verification performed on the Cask and Multiple Canister Over-pack (MCO) Helium Purge System. The helium purge system is part of the Spent Nuclear Fuel (SNF) Project Cask Loadout System (CLS) at 100K area. The design verification employed the ''Independent Review Method'' in accordance with Administrative Procedure (AP) EN-6-027-01.

ARD, K.E.

2000-04-19T23:59:59.000Z

465

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

466

Diffusional exchange of isotopes in a metal hydride sphere.  

DOE Green Energy (OSTI)

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

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

2011-04-01T23:59:59.000Z

467

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

468

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

469

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

470

First AID (Atom counting for Isotopic Determination).  

SciTech Connect

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

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

2002-01-01T23:59:59.000Z

471

Integrated Geochronologic, Geochemical, and Sedimentological Investigation of Proterozoic-Early Paleozoic Strata: From Northern India to Global Perspectives  

E-Print Network (OSTI)

isotope   systematics  of  the  Vindhyan  Supergroup,  India.  Geology  isotope  trends  from  Aravalli  strata.   Regional  geology  and  

McKenzie, Neil Ryan

2012-01-01T23:59:59.000Z

472

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

E-Print Network (OSTI)

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

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

2005-01-01T23:59:59.000Z

473

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

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

Research » Isotope Research » Isotope Development & Production for Research and Applications (IDPRA) Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Research Isotope Development & Production for Research and Applications (IDPRA) Print Text Size: A A A RSS Feeds FeedbackShare Page The Isotope subprogram supports the production, and the development of production techniques of radioactive and stable isotopes that are in short supply for research and applications. Isotopes are high-priority

474

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

Open Energy Info (EERE)

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

475

Plutonium isotopic analysis of highly enriched mixed oxides  

SciTech Connect

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

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

1986-08-01T23:59:59.000Z

476

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

Open Energy Info (EERE)

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

477

Isotopic Analysis- Fluid At Indian Valley Hot Springs Geothermal Area  

Open Energy Info (EERE)

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

478

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

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

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

479

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

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

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

480

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

Open Energy Info (EERE)

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