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Note: This page contains sample records for the topic "hfcs perfluorocarbons pfcs" from the National Library of EnergyBeta (NLEBeta).
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1

The greenhouse gases HFCs, PFCs Danish consumption and emissions, 2007  

E-Print Network [OSTI]

The greenhouse gases HFCs, PFCs and SF6 Danish consumption and emissions, 2007 Tomas Sander Poulsen AND EMISSION OF F-GASES 7 1.1.1 Consumption 7 1.1.2 Emission 7 1.1.3 Trends in total GWP contribution from F 21 4 EMISSION OF F-GASES 23 4.1.1 Emissions of HFCs from refrigerants 23 4.1.2 Emissions of HFCs from

2

Method for enhancing microbial utilization rates of gases using perfluorocarbons  

DOE Patents [OSTI]

A method of enhancing the bacterial reduction of industrial gases using perfluorocarbons (PFCs) is disclosed. Because perfluorocarbons (PFCs) allow for a much greater solubility of gases than water does, PFCs have the potential to deliver gases in higher concentrations to microorganisms when used as an additive to microbial growth media thereby increasing the rate of the industrial gas conversion to economically viable chemicals and gases.

Turick, Charles E. (Idaho Falls, ID)

1997-01-01T23:59:59.000Z

3

Method for enhancing microbial utilization rates of gases using perfluorocarbons  

DOE Patents [OSTI]

A method of enhancing the bacterial reduction of industrial gases using perfluorocarbons (PFCs) is disclosed. Because perfluorocarbons (PFCs) allow for a much greater solubility of gases than water does, PFCs have the potential to deliver gases in higher concentrations to microorganisms when used as an additive to microbial growth media thereby increasing the rate of the industrial gas conversion to economically viable chemicals and gases. 3 figs.

Turick, C.E.

1997-06-10T23:59:59.000Z

4

Trends and inferred emissions of atmospheric high molecular weight perfluorocarbons  

E-Print Network [OSTI]

Atmospheric observations and atmospheric observation-based global emission estimates are presented for the five high molecular weight perfluorocarbons (PFCs): decafluorobutane (C 4 F 1 0 ), dodecafluoropentane (C5 F1 2 ), ...

Ivy, Diane Jean

2012-01-01T23:59:59.000Z

5

Perfluorocarbons in the global atmosphere: tetrafluoromethane, hexafluoroethane, and octafluoropropane  

E-Print Network [OSTI]

We present atmospheric baseline growth rates from the 1970s to the present for the long-lived, strongly infrared-absorbing perfluorocarbons (PFCs) tetrafluoromethane (CF4), hexafluoroethane (C2F6), and octafluoropropane ...

Muhle, J.

6

Perfluorocarbon tracer method for air-infiltration measurements  

DOE Patents [OSTI]

A method of measuring air infiltration rates suitable for use in rooms of homes and buildings comprises the steps of emitting perfluorocarbons in the room to be measured, sampling the air containing the emitted perfluorocarbons over a period of time, and analyzing the samples at a laboratory or other facility.

Dietz, R.N.

1982-09-23T23:59:59.000Z

7

QUANTIFICATION OF FUGITIVE REACTIVE ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS.  

SciTech Connect (OSTI)

Recent studies demonstrate the impact of fugitive emissions of reactive alkenes on the atmospheric chemistry of the Houston Texas metropolitan area (1). Petrochemical plants located in and around the Houston area emit atmospheric alkenes, such as ethene, propene and 1,3-butadiene. The magnitude of emissions is a major uncertainty in assessing their effects. Even though the petrochemical industry reports that fugitive emissions of alkenes have been reduced to less than 0.1% of daily production, recent measurement data, obtained during the TexAQS 2000 experiment indicates that emissions are perhaps a factor of ten larger than estimated values. Industry figures for fugitive emissions are based on adding up estimated emission factors for every component in the plant to give a total estimated emission from the entire facility. The dramatic difference between estimated and measured rates indicates either that calculating emission fluxes by summing estimates for individual components is seriously flawed, possibly due to individual components leaking well beyond their estimated tolerances, that not all sources of emissions for a facility are being considered in emissions estimates, or that there are known sources of emissions that are not being reported. This experiment was designed to confirm estimates of reactive alkene emissions derived from analysis of the TexAQS 2000 data by releasing perfluorocarbon tracers (PFTs) at a known flux from a petrochemical plant and sampling both the perfluorocarbon tracer and reactive alkenes downwind using the Piper-Aztec research aircraft operated by Baylor University. PFTs have been extensively used to determine leaks in pipelines, air infiltration in buildings, and to characterize the transport and dispersion of air parcels in the atmosphere. Over 20 years of development by the Tracer Technology Center (TTC) has produced a range of analysis instruments, field samplers and PFT release equipment that have been successfully deployed in a large variety of experiments. PFTs are inert, nontoxic, noncombustible and nonreactive. Up to seven unique PFTs can be simultaneously released, sampled and analyzed and the technology is well suited for determining emission fluxes from large petrochemical facilities. The PFT experiment described here was designed to quantitate alkene emissions from a single petrochemical facility, but such experiments could be applied to other industrial sources or groups of sources in the Houston area.

SENUM,G.I.; DIETZ,R.N.

2004-06-30T23:59:59.000Z

8

A Really Good Hammer: Quantification of Mass Transfer Using Perfluorocarbon Tracers (475th Brookhaven Lecture)  

SciTech Connect (OSTI)

Brookhaven Lab’s perfluorocarbon tracer (PFT) technology can be viewed as a hammer looking for nails. But, according to Tom Watson, leader of the Lab’s Tracer Technology Group in the Environmental Research and Technology Division (ERTD), “It’s a really good hammer!” The colorless, odorless and safe gases have a number of research uses, from modeling how airborne contaminants might move through urban canyons to help first responders plan their response to potential terrorist attacks and accidents to locating leaks in underground gas pipes. Their extremely low background level — detectable at one part per quadrillion — allows their transport to be easily tracked. Lab researchers used PFTs during the 2005 Urban Dispersion Program field studies in New York City, gathering data to help improve models of how a gas or chemical release might move around Manhattan’s tall buildings and canyons. Closer to home, scientists also used PFTs to make ventilation measurements in Bldg. 400 on the Lab site to provide data to test air flow models used in determining the effects of passive and active air exchange on the levels of indoor and outdoor air pollution, and to determine the effects of an accidental or intentional release of hazardous substances in or around buildings.

Watson, Tom [BNL Environmental Sciences, Tracer Technology Group

2012-02-15T23:59:59.000Z

9

Measurement of HVAC system performance and local ventilation using passive perfluorocarbon tracer technology  

SciTech Connect (OSTI)

In April of 1993, two (2) perfluorocarbon tracer (PFT) ventilation/indoor air quality assessment tests were performed in the Gleeson Hall building of the SUNY Farmingdale campus. The building was being modified, in part, as a result of significant occupant complaints of perceived poor air quality. The four story building had a basement first floor with air supplied normally by an HVAC system labelled as AC1. During this study, AC1 was inoperational and the basement interior rooms (walls) were primarily gone; the other three floors were still being used for classes. It is possible that a sense of poor air quality may have been perceived by first-floor occupants because they were working in the basement, but this issue could not be addressed. The second floor had two (2) lecture halls--Rm 202 (handled by AC4) and Rm 204 (handled by AC5); the balance of the second floor interior rooms and corridors was split between two other air handling systems, AC2 for the west side of the building and AC3 for the east side. The remaining 3rd and 4th floors were also split about evenly between AC2 and AC3. The perimeter rooms, equipped with wall units having their own outside air (OA) source plus centralized return air (RA) bypasses, were not included in this testing which was restricted to the basement floor (1st floor) and the four operating air handling systems, AC2 to AC5, during Test 1 and only AC2 to AC5 during Test 2. Two types of tests were performed using the full suite of 5 PFT types available. The first test was designed to measure the infiltration, exfiltration, and air exchange between the 5 AC zones above and the second test used the 5th tracer, which had been in the basement, as a distributed source throughout the four other zones to act as a surrogate pollutant source. This report provides final conclusions of both tests and suggestions regarding its usefulness in similar building ventilation and indoor air quality assessments.

Dietz, R.N.; Goodrich, R.W.

1995-06-01T23:59:59.000Z

10

USING PERFLUOROCARBON TRACERS FOR VERIFICATION OF CAP AND COVER SYSTEMS PERFORMANCE.  

SciTech Connect (OSTI)

The Department of Energy (DOE) Environmental Management (EM) office has committed itself to an accelerated cleanup of its national facilities. The goal is to have much of the DOE legacy waste sites remediated by 2006. This includes closure of several sites (e.g., Rocky Flats and Fernald). With the increased focus on accelerated cleanup, there has been considerable concern about long-term stewardship issues in general, and verification and long-term monitoring (LTM) of caps and covers, in particular. Cap and cover systems (covers) are vital remedial options that will be extensively used in meeting these 2006 cleanup goals. Every buried waste site within the DOE complex will require some form of cover system. These covers are expected to last from 100 to 1000 years or more. The stakeholders can be expected to focus on system durability and sustained performance. DOE EM has set up a national committee of experts to develop a long-term capping (LTC) guidance document. Covers are subject to subsidence, erosion, desiccation, animal intrusion, plant root infiltration, etc., all of which will affect the overall performance of the cover. Very little is available in terms of long-term monitoring other than downstream groundwater or surface water monitoring. By its very nature, this can only indicate that failure of the cover system has already occurred and contaminants have been transported away from the site. This is unacceptable. Methods that indicate early cover failure (prior to contaminant release) or predict approaching cover failure are needed. The LTC committee has identified predictive monitoring technologies as a high priority need for DOE, both for new covers as well as existing covers. The same committee identified a Brookhaven National Laboratory (BNL) technology as one approach that may be capable of meeting the requirements for LTM. The Environmental Research and Technology Division (ERTD) at BNL developed a novel methodology for verifying and monitoring subsurface barriers (1,2). The technology uses perfluorocarbon tracers (PFTs) to determine flaws (e.g., holes or cracks) and high permeability areas in subsurface barriers. Gaseous tracers are injected on one side of the barrier and searched for on the opposite side of the barrier. The sampling grid, concentration, and time of arrival of the tracer(s) on the opposite side are used to determine the size and location of flaws and relative permeability of the barrier. In addition, there are multiple tracers available, which allows different tracers to be injected in different quadrants of the barrier. This yields additional information on transport phenomena of the barrier.

HEISER,J.; SULLIVAN,T.

2001-11-01T23:59:59.000Z

11

The State of the CDM & its Contribution to SD  

E-Print Network [OSTI]

distribution of CDM projects 2012 CER Total in the CDM Pipeline kCERs Population per cap. Latin America 609 23 category Renewables 61% Demand-side EE 5% Supply-side EE 11% Fuel sw itch 3% HFCs, PFCs & N2O reduction 2% Supply-side EE 10% CH4 reduction & Cement & Coal mine/bed 20% Renewables 28% HFCs, PFCs & N2O reduction

12

Global emission estimates and radiative impact of C[subscript 4]F[subscript 10], C[subscript 5]F[subscript 12], C[subscript 6]F[subscript 14], C[subscript 7]F[subscript 16] and C[subscript 8]F[subscript 18  

E-Print Network [OSTI]

Global emission estimates based on new atmospheric observations are presented for the acylic high molecular weight perfluorocarbons (PFCs): decafluorobutane (C[subscript 4]F[subscript 10]), dodecafluoropentane (C[subscript ...

Ivy, Diane J.

13

Primary aluminum production : climate policy, emissions and costs  

E-Print Network [OSTI]

Climate policy regarding perfluorocarbons (PFCs) may have a significant influence on investment decisions in the production of primary aluminum. This work demonstrates an integrated analysis of the effectiveness and likely ...

Harnisch, Jochen.; Sue Wing, Ian.; Jacoby, Henry D.; Prinn, Ronald G.

14

Emissions of greenhouse gases in the United States 1995  

SciTech Connect (OSTI)

This is the fourth Energy Information Administration (EIA) annual report on US emissions of greenhouse gases. This report presents estimates of US anthropogenic (human-caused) emissions of carbon dioxide, methane, nitrous oxide, and several other greenhouse gases for 1988 through 1994. Estimates of 1995 carbon dioxide, nitrous oxide, and halocarbon emissions are also provided, although complete 1995 estimates for methane are not yet available. Emissions of carbon dioxide increased by 1.9% from 1993 to 1994 and by an additional 0.8% from 1994 to 1995. Most carbon dioxide emissions are caused by the burning of fossil fuels for energy consumption, which is strongly related to economic growth, energy prices, and weather. The US economy grew rapidly in 1994 and slowed in 1995. Estimated emissions of methane increased slightly in 1994, as a result of a rise in emissions from energy and agricultural sources. Estimated nitrous oxide emissions increased by 1.8% in 1995, primarily due to increased use of nitrogen fertilizers and higher output of chemicals linked to nitrous oxide emissions. Estimated emissions of hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), which are known to contribute to global warming, increased by nearly 11% in 1995, primarily as a result of increasing substitution for chlorofluorocarbons (CFCs). With the exception of methane, the historical emissions estimates presented in this report are only slightly revised from those in last year`s report.

NONE

1996-10-01T23:59:59.000Z

15

THE BROOKHAVEN NATIONAL LABORATORY PERFLUOROCARBON TRACER TECHNOLOGY: A PROVEN AND COST EFFECTIVE METHOD TO VERIFY INTEGRITY AND MONITOR LONG TERM PERFORMANCE OF WALLS, FLOORS, CAPS, AND COVER SYSTEMS.  

SciTech Connect (OSTI)

Currently, containment system failures are detected by monitoring wells downstream of the waste site. Clearly this approach is inefficient, as the contaminants will have migrated from the disposal area before they are detected. Methods that indicate early cover failure (prior to contaminant release) or predict impending cover failure are needed. The Brookhaven National Laboratory (BNL) Perfluorocarbon Tracer (PFT) technology can measure performance changes and integrity losses as the cover ages. This allows early detection of cover failure or pending failure so that repair or replacement can be made before contaminants leave the disposal cell. The PFT technology has been successfully applied to four subsurface barrier problems, one leak detection problem from underground ducts, and one surface cover problem. Testing has demonstrated that the PFTs are capable of accurately detecting and locating leaks down to fractions of an inch. The PFT technology has several advantages over competing approaches. The ability to simultaneously use multiple PFTs separates it from other gas tracer technologies. Using multiple tracers provides independent confirmation of flaw location, helps to clearly define transport pathways, and can be used for confirmatory testing (e.g., repeat the test using a new tracer). The PFT tests provide a direct measure of flaws in a barrier, whereas other measurements (pressure, moisture content, temperature, subsidence) provide indirect measures that need interpretation. The focus of the six PFT demonstrations has been on engineering aspects of the technology with the intent of finding if a flaw existed in the barrier. Work remains to be done on the scientific basis for this technology. This includes determining PFT diffusion rates through various materials (soils and barrier) as a function of moisture content, determining the effects of barometric pumping on PFT flow for cover systems, and determining wind effects on side slopes of cover systems and their impact on PFT performance. It also includes application of models to assist in the design of the monitoring system and the interpretation of the data. The set of demonstrations was performed on small sites (< 1/4 acre). Future work also needs to consider scaling issues to develop and design optimal techniques for delivery and monitoring of the PFTs.

HEISER, J.; SULLIVAN, T.

2002-03-11T23:59:59.000Z

16

Greenhouse Gas Management Program Overview (Fact Sheet)  

SciTech Connect (OSTI)

Program fact sheet highlighting federal requirements for GHG emissions management, FEMP services to help agencies reduce emissions, and additional resources. The U.S. Department of Energy (DOE) Federal Energy Management Program (FEMP) assists Federal agencies with managing their greenhouse gas (GHG) emissions. GHG management entails measuring emissions and understanding their sources, setting a goal for reducing emissions, developing a plan to meet this goal, and implementing the plan to achieve reductions in emissions. FEMP provides the following services to help Federal agencies meet the requirements of inventorying and reducing their GHG emissions: (1) FEMP offers one-on-one technical assistance to help agencies understand and implement the Federal Greenhouse Gas Accounting and Reporting Guidance and fulfill their inventory reporting requirements. (2) FEMP provides training, tools, and resources on FedCenter to help agencies complete their annual inventories. (3) FEMP serves a leadership role in the interagency Federal Working Group on Greenhouse Gas Accounting and Reporting that develops recommendations to the Council on Environmental Quality (CEQ) for the Federal Greenhouse Gas Accounting and Reporting Guidance. (4) As the focus continues to shift from measuring emissions (completing inventories) to mitigating emissions (achieving reductions), FEMP is developing a strategic planning framework and resources for agencies to prioritize among a variety of options for mitigating their GHG emissions, so that they achieve their reduction goals in the most cost-effective manner. These resources will help agencies analyze their high-quality inventories to make strategic decisions about where to use limited resources to have the greatest impact on reducing emissions. Greenhouse gases trap heat in the lower atmosphere, warming the earth's surface temperature in a natural process known as the 'greenhouse effect.' GHGs include carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF{sub 6}). Human activities have caused a rapid increase in GHG concentrations. This rising level contributes to global climate change, which contributes to environmental and public health problems.

Not Available

2011-11-01T23:59:59.000Z

17

Atmospheric and soil-gas monitoring for surface leakage at the San Juan Basin CO{sub 2} pilot test site at Pump Canyon New Mexico, using perfluorocarbon tracers, CO{sub 2} soil-gas flux and soil-gas hydrocarbons  

SciTech Connect (OSTI)

Near-surface monitoring and subsurface characterization activities were undertaken in collaboration with the Southwest Regional Carbon Sequestration Partnership on their San Juan Basin coal-bed methane pilot test site near Navajo City, New Mexico. Nearly 18,407 short tons (1.670 × 107 kg) of CO{sub 2} were injected into 3 seams of the Fruitland coal between July 2008 and April 2009. Between September 18 and October 30, 2008, two additions of approximately 20 L each of perfluorocarbon (PFC) tracers were mixed with the CO{sub 2} at the injection wellhead. PFC tracers in soil-gas and in the atmosphere were monitored over a period of 2 years using a rectangular array of permanent installations. Additional monitors were placed near existing well bores and at other locations of potential leakage identified during the pre-injection site survey. Monitoring was conducted using sorbent containing tubes to collect any released PFC tracer from soil-gas or the atmosphere. Near-surface monitoring activities also included CO{sub 2} surface flux and carbon isotopes, soil-gas hydrocarbon levels, and electrical conductivity in the soil. The value of the PFC tracers was demonstrated when a significant leakage event was detected near an offset production well. Subsurface characterization activities, including 3D seismic interpretation and attribute analysis, were conducted to evaluate reservoir integrity and the potential that leakage of injected CO{sub 2} might occur. Leakage from the injection reservoir was not detected. PFC tracers made breakthroughs at 2 of 3 offset wells which were not otherwise directly observable in produced gases containing 20–30% CO{sub 2}. These results have aided reservoir geophysical and simulation investigations to track the underground movement of CO{sub 2}. 3D seismic analysis provided a possible interpretation for the order of appearance of tracers at production wells.

Wells, Arthur W.; Diehl, J. Rodney; Strazisar, Brian R.; Wilson, Thomas; H Stanko, Dennis C.

2012-05-01T23:59:59.000Z

18

MAU 1 3/13/00 Disruption Effects on FIRE PFCs  

E-Print Network [OSTI]

Loads · Thermal Quench Phase ­ 33 MJ stored thermal energy ­ Loss time 0.2 ms ­ Heated area - Thermal Quench · Energy deposition on the divertor plates ­ Inner: 8.5 to 21.8 MJ/m2 or 42.5 to 109 GW/m2 Interface Fixed Brackets Engage Pins that Attach to Vessel Vacuum Port Envelope Radial Drive Shaft Locations

19

Splashing and boiling mechanisms of melt layer losses of PFCs during plasma instabilities  

E-Print Network [OSTI]

that includes the heat transfer and vaporization effects is developed using the open-source OpenFoam CFD, heat transfer, and mass ex- change across the interface [10,11]. The critical velocity as a function of wavelength is analyzed for various values of plasma viscosity and heat transfer coefficient. The CFD solver

Harilal, S. S.

20

Trends and Inferred Emissions of Atmospheric High Molecular Weight Perfluorocarbons  

E-Print Network [OSTI]

) and octadecafluorooctane (C8F18). Their atmospheric histories are based on measurements of 36 Northern Hemisphere and 468F18. Based on our observations, the 2011 globally averaged dry air mole fractions of these high12, 0.27 ppt for C6F14, 0.12 ppt for C7F16 and 0.09 ppt for C8F18. Newly measured infrared absorption

Note: This page contains sample records for the topic "hfcs perfluorocarbons pfcs" 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

Controlling the hydrogenic fuel inventory in plasma facing components (PFCs) will be necessary for the successful operation of  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01Controlling Graphene'sBottom-Up.Electrodesnew

22

Controlling the hydrogenic fuel inventory in plasma facing components (PFCs) will be necessary for the successful operation of  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New SubstationCleanCommunity2Workshops01Controlling

23

Laboratory testing and modeling to evaluate perfluorocarbon compounds as tracers in geothermal systems  

SciTech Connect (OSTI)

The thermal stability and adsorption characteristics of three perfluorinated hydrocarbon compounds were evaluated under geothermal conditions to determine the potential to use these compounds as conservative or thermally-degrading tracers in Engineered (or Enhanced) Geothermal Systems (EGS). The three compounds tested were perfluorodimethyl-cyclobutane (PDCB), perfluoromethylcyclohexane (PMCH), and perfluorotrimethylcyclohexane (PTCH), which are collectively referred to as perfluorinated tracers, or PFTs. Two sets of duplicate tests were conducted in batch mode in gold-bag reactors, with one pair of reactors charged with a synthetic geothermal brine containing the PFTs and a second pair was charged with the brine-PFT mixture plus a mineral assemblage chosen to be representative of activated fractures in an EGS reservoir. A fifth reactor was charged with deionized water containing the three PFTs. The experiments were conducted at {approx}100 bar, with temperatures ranging from 230 C to 300 C. Semi-analytical and numerical modeling was also conducted to show how the PFTs could be used in conjunction with other tracers to interrogate surface area to volume ratios and temperature profiles in EGS reservoirs. Both single-well and cross-hole tracer tests are simulated to illustrate how different suites of tracers could be used to accomplish these objectives. The single-well tests are especially attractive for EGS applications because they allow the effectiveness of a stimulation to be evaluated without drilling a second well.

Reimus, Paul W [Los Alamos National Laboratory

2011-01-21T23:59:59.000Z

24

Feasibility of a Perfluorocarbon tracer based network to support Monitoring, Verification, and Accounting of Sequestered CO2  

E-Print Network [OSTI]

, and Accounting of Sequestered CO2 Thomas B. Watson* and Terrence Sullivan Brookhaven National Laboratory, Upton% of total sequestered CO2 over the lifetime of the reservoir. This is 0.001% per year for a 1000 year lifetime of a storage reservoir. Effective detection of CO2 leaks at the surface may require incorporation

Johnson, Peter D.

25

Millenium Science Complex New clean room: 10,000 sq. ft. class 100/1000  

E-Print Network [OSTI]

-ring outgassing · All high temperature O-rings made of fluorocarbon or perfluorocarbon materials have this issue

26

E-Print Network 3.0 - alkenes Sample Search Results  

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

was performed under the auspices of the U.S. Department Summary: ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS Gunnar I. Senum and Russell N... of...

27

BNL-73106-2004-IR Research by BNL investigators was performed under the auspices of the U.S. Department  

E-Print Network [OSTI]

ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS Gunnar I. Senum and Russell N (1). Petrochemical plants located in and around the Houston area emit atmospheric alkenes by releasing perfluorocarbon tracers (PFTs) at a known flux from a petrochemical plant and sampling both

28

E-Print Network 3.0 - armoured actively cooled Sample Search...  

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

on the actively cooled plasma facing components (PFCs) of the International Thermonuclear Experimental Reactor... of the actively cooled component itself. These have...

29

Reliability of Heat Pumps Containing R410-A Refrigerant  

E-Print Network [OSTI]

on alternate refrigerants. One major manufacturer announced a formation of black smudge on internal surfaces of field trial units using HFCs. Several causes were suggested but none were published. Reports of capillary tube plugging were wide spread. Polyol...

McJimsey, B. A.; Cawley, D.

1998-01-01T23:59:59.000Z

30

A Comparison of Fault Detection Methods For a Transcritical Refrigeration System  

E-Print Network [OSTI]

on Climate Change, eleven of the twelve years between 1995 and 2006 ranked with the highest temperatures since direct measurement has been available [3]. The use of hydroflourocarbons (HFCs) as refrigerants contributes to climate change. Global warming...

Janecke, Alex Karl

2012-10-19T23:59:59.000Z

31

Wind Power and the Clean Development Mechanism  

E-Print Network [OSTI]

Biogas Cement HFCs Geothermal EE Households Solar N2O Fugitive Tidal EE Service Transport Energy distrib 200 300 400 500 600 700 Lara Landfill (10 MW) Korat Biogas (3 MW) Rukmani Rice Husk (10 MW) Palestina

32

Infrared absorption spectra, radiative efficiencies, and global warming potentials  

E-Print Network [OSTI]

Infrared absorption spectra, radiative efficiencies, and global warming potentials absorption spectra, radiative efficiencies, and global warming potentials of perfluorocarbons: Comparison. (1995) and combined with atmospheric lifetimes from the literature to determine global warming

Wirosoetisno, Djoko

33

Update in Fluoroelastomers : fromPerfluoroelastomers to Fluorosilicones and Fluorophosphazenes  

E-Print Network [OSTI]

of the fluoroelastomers, ranging from (per)fluorocarbon elastomers to fluorophosphazenes, and fluorosilicones. 2 to be crosslinked and those are do not 2-1 Fluorocarbon elastomers. Usually, fluorocarbon elastomers are synthesised

Boyer, Edmond

34

Evaluation of metrics and baselines for tracking greenhouse gas emissions trends: Recommendations for the California climate action registry  

SciTech Connect (OSTI)

Executive Summary: The California Climate Action Registry, which was initially established in 2000 and began operation in Fall 2002, is a voluntary registry for recording annual greenhouse gas (GHG) emissions. The purpose of the Registry is to assist California businesses and organizations in their efforts to inventory and document emissions in order to establish a baseline and to document early actions to increase energy efficiency and decrease GHG emissions. The State of California has committed to use its ''best efforts'' to ensure that entities that establish GHG emissions baselines and register their emissions will receive ''appropriate consideration under any future international, federal, or state regulatory scheme relating to greenhouse gas emissions.'' Reporting of GHG emissions involves documentation of both ''direct'' emissions from sources that are under the entity's control and indirect emissions controlled by others. Electricity generated by an off-site power source is consider ed to be an indirect GHG emission and is required to be included in the entity's report. Registry participants include businesses, non-profit organizations, municipalities, state agencies, and other entities. Participants are required to register the GHG emissions of all operations in California, and are encouraged to report nationwide. For the first three years of participation, the Registry only requires the reporting of carbon dioxide (CO2) emissions, although participants are encouraged to report the remaining five Kyoto Protocol GHGs (CH4, N2O, HFCs, PFCs, and SF6). After three years, reporting of all six Kyoto GHG emissions is required. The enabling legislation for the Registry (SB 527) requires total GHG emissions to be registered and requires reporting of ''industry-specific metrics'' once such metrics have been adopted by the Registry. The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) was asked to provide technical assistance to the California Energy Commission (Energy Commission) related to the Registry in three areas: (1) assessing the availability and usefulness of industry-specific metrics, (2) evaluating various methods for establishing baselines for calculating GHG emissions reductions related to specific actions taken by Registry participants, and (3) establishing methods for calculating electricity CO2 emission factors. The third area of research was completed in 2002 and is documented in Estimating Carbon Dioxide Emissions Factors for the California Electric Power Sector (Marnay et al., 2002). This report documents our findings related to the first areas of research. For the first area of research, the overall objective was to evaluate the metrics, such as emissions per economic unit or emissions per unit of production that can be used to report GHG emissions trends for potential Registry participants. This research began with an effort to identify methodologies, benchmarking programs, inventories, protocols, and registries that u se industry-specific metrics to track trends in energy use or GHG emissions in order to determine what types of metrics have already been developed. The next step in developing industry-specific metrics was to assess the availability of data needed to determine metric development priorities. Berkeley Lab also determined the relative importance of different potential Registry participant categories in order to asses s the availability of sectoral or industry-specific metrics and then identified industry-specific metrics in use around the world. While a plethora of metrics was identified, no one metric that adequately tracks trends in GHG emissions while maintaining confidentiality of data was identified. As a result of this review, Berkeley Lab recommends the development of a GHG intensity index as a new metric for reporting and tracking GHG emissions trends.Such an index could provide an industry-specific metric for reporting and tracking GHG emissions trends to accurately reflect year to year changes while protecting proprietary data. This GHG intensity index changes

Price, Lynn; Murtishaw, Scott; Worrell, Ernst

2003-06-01T23:59:59.000Z

35

Industry  

SciTech Connect (OSTI)

This chapter addresses past, ongoing, and short (to 2010) and medium-term (to 2030) future actions that can be taken to mitigate GHG emissions from the manufacturing and process industries. Globally, and in most countries, CO{sub 2} accounts for more than 90% of CO{sub 2}-eq GHG emissions from the industrial sector (Price et al., 2006; US EPA, 2006b). These CO{sub 2} emissions arise from three sources: (1) the use of fossil fuels for energy, either directly by industry for heat and power generation or indirectly in the generation of purchased electricity and steam; (2) non-energy uses of fossil fuels in chemical processing and metal smelting; and (3) non-fossil fuel sources, for example cement and lime manufacture. Industrial processes also emit other GHGs, e.g.: (1) Nitrous oxide (N{sub 2}O) is emitted as a byproduct of adipic acid, nitric acid and caprolactam production; (2) HFC-23 is emitted as a byproduct of HCFC-22 production, a refrigerant, and also used in fluoroplastics manufacture; (3) Perfluorocarbons (PFCs) are emitted as byproducts of aluminium smelting and in semiconductor manufacture; (4) Sulphur hexafluoride (SF{sub 6}) is emitted in the manufacture, use and, decommissioning of gas insulated electrical switchgear, during the production of flat screen panels and semiconductors, from magnesium die casting and other industrial applications; (5) Methane (CH{sub 4}) is emitted as a byproduct of some chemical processes; and (6) CH{sub 4} and N{sub 2}O can be emitted by food industry waste streams. Many GHG emission mitigation options have been developed for the industrial sector. They fall into three categories: operating procedures, sector-wide technologies and process-specific technologies. A sampling of these options is discussed in Sections 7.2-7.4. The short- and medium-term potential for and cost of all classes of options are discussed in Section 7.5, barriers to the application of these options are addressed in Section 7.6 and the implication of industrial mitigation for sustainable development is discussed in Section 7.7. Section 7.8 discusses the sector's vulnerability to climate change and options for adaptation. A number of policies have been designed either to encourage voluntary GHG emission reductions from the industrial sector or to mandate such reductions. Section 7.9 describes these policies and the experience gained to date. Co-benefits of reducing GHG emissions from the industrial sector are discussed in Section 7.10. Development of new technology is key to the cost-effective control of industrial GHG emissions. Section 7.11 discusses research, development, deployment and diffusion in the industrial sector and Section 7.12, the long-term (post-2030) technologies for GHG emissions reduction from the industrial sector. Section 7.13 summarizes gaps in knowledge.

Bernstein, Lenny; Roy, Joyashree; Delhotal, K. Casey; Harnisch, Jochen; Matsuhashi, Ryuji; Price, Lynn; Tanaka, Kanako; Worrell, Ernst; Yamba, Francis; Fengqi, Zhou; de la Rue du Can, Stephane; Gielen, Dolf; Joosen, Suzanne; Konar, Manaswita; Matysek, Anna; Miner, Reid; Okazaki, Teruo; Sanders, Johan; Sheinbaum Parado, Claudia

2007-12-01T23:59:59.000Z

36

Comparison of H-Mode Plasmas Diverted to Solid and Liquid Lithium Surfaces  

SciTech Connect (OSTI)

Experiments were conducted with a Liquid Lithium Divertor (LLD) in NSTX. Among the goals was to use lithium recoating to sustain deuterium (D) retention by a static liquid lithium surface, approximating the ability of flowing liquid lithium to maintain chemical reactivity. Lithium evaporators were used to deposit lithium on the LLD surface. Improvements in plasma edge conditions were similar to those with lithiated graphite plasma-facing components (PFCs), including an increase in confinement over discharges without lithiumcoated PFCs and ELM reduction during H-modes. With the outer strike point on the LLD, the D retention in the LLD was about the same as that for solid lithium coatings on graphite, or about two times that achieved without lithium PFC coatings. There were also indications of contamination of the LLD surface, possibly due erosion and redeposition of carbon from PFCs. Flowing lithium may thus be needed for chemically active PFCs during long-pulse operation.

R. Kaita, et. al.

2012-07-20T23:59:59.000Z

37

Philosophical Magazine Letters, Vol. 86, No. 2, February 2006, 123136  

E-Print Network [OSTI]

) fibre-reinforced composites (FRCs), although the interfacial load transfer mechanism in PFCs is similar and sensing, the ability to overcome low fracture strength and conform to curved surfaces, among others [2, 3

Qin, Qinghua

38

E-Print Network 3.0 - actively cooled plasma-facing Sample Search...  

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

m2. Each cassette... - The ITER plasma-facing components (PFCs) directly face the thermonuclear plasma and cover an area of about... of a plasma facing material (armour) mounted...

39

Evaluation of unsaturated fluorocarbons for dielectric Etch applications  

E-Print Network [OSTI]

The semiconductor industry is currently faced with the problem of the use and emissions of strong global warming compounds, known as perfluorocompounds (PFCs) for dielectric etch applications. The release of global warming ...

Chatterjee, Ritwik, 1974-

2003-01-01T23:59:59.000Z

40

INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES The French APACHE project aims at  

E-Print Network [OSTI]

commercially available fuel cell vehicles [1­4]. Several projects of fuel cell aircrafts intend to demonstrate at demonstrating the feasibility of using a Hybrid Fuel Cell System (HFCS) as the power generator for all electric Fuel Cells (PEMFC), their hybridization with Lithium Ion (Li-Ion) batteries and systems' integration

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "hfcs perfluorocarbons pfcs" 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

Atmospheric histories and global emissions of the anthropogenic hydrofluorocarbons HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa  

E-Print Network [OSTI]

We report on ground-based atmospheric measurements and emission estimates of the four anthropogenic hydrofluorocarbons (HFCs) HFC-365mfc (CH[subscript 3]CF[subscript 2]CH[subscript 2]CF[subscript 3], 1,1,1,3,3-pentafluorobutane), ...

Rigby, Matthew

42

Transportation and Greenhouse Gas Emissions: Measurement, Causation and Mitigation  

E-Print Network [OSTI]

.S. CO2 emissions sources. U.S. CO2 transportation emissions sources by mode. #12;Center% of the carbon dioxide we produce. As such it is a leading candidate for greenhouse gas ((GHG) (CO2, NH4, HFCsTransportation and Greenhouse Gas Emissions: Measurement, Causation and Mitigation Oak Ridge

43

Effect of Lithium PFC Coatings on NSTX Density Control  

SciTech Connect (OSTI)

Lithium coatings on the graphite plasma facing components (PFCs) in NSTX are being investigated as a tool for density profile control and reducing the recycling of hydrogen isotopes. Repeated lithium pellet injection into Center Stack Limited and Lower Single Null Ohmic Helium Discharges were used to coat graphite surfaces that had been pre-conditioned with Ohmic Helium Discharges of the same shape to reduce their contribution to hydrogen isotope recycling. The following deuterium NBI reference discharges exhibited a reduction in density by a factor of about 3 for limited and 2 for diverted plasmas respectively, and peaked density profiles. Recently, a lithium evaporator has been used to apply thin coatings on conditioned and unconditioned PFCs. Effects on the plasma density and the impurities were obtained by pre-conditioning the PFCs with ohmic helium discharges, and performing the first deuterium NBI discharge as soon as possible after applying the lithium coating.

Kugel, H W; Bell, M G; Bush, C; Gates, D; Gray, T; Kaita, R; Leblanc, B; Maingi, R; Majeski, R; Mansfield, D; Mueller, D; Raman, R; Roquemore, A L; Sabbagh, S; Skinner, C H; Soukhanovskii, V; Stevenson, T; Zakharov, L

2006-08-21T23:59:59.000Z

44

Fracture Model, Ground Displacements and Tracer Observations: Fruitland Coals, San Juan Basin, New Mexico,  

E-Print Network [OSTI]

that the coal reservoirs consist of six separate coal beds rather than three. Perfluorocarbon tracer monitoring the site consist of two coal beds, each separated by a shale parting. This observation indicates will improve our understanding of Fruitland coal reservoirs; help develop more effective strategies to enhance

Wilson, Thomas H.

45

NOAA ARL Monthly Activity Report January 2005  

E-Print Network [OSTI]

. SURFRAD/ISIS 9. DHS Model Evaluation Planning 10. U.S. Climate Reference 11. Community Multiscale Air. Tracer Analysis Facility (TAF) Adaptation for Perfluorocarbon Tracer Analysis 19. Smart Balloon" Method for DCNet added to READY. A routine that inserts DCNet tower observations into the Eta gridded

46

Environment International, Vol. 8, pp. 419-433, 1982 0160-4120/82/070419-15503.00/0 Printed in the USA. All rights reserved. Copyright 1982 Pergamon Press Ltd.  

E-Print Network [OSTI]

perfluorocarbon tracer (PFT) sources and miniature passive samplers, both about the size of a cigarette, tests of passive adsorption tube samplers performed reproducibly and identically (to within + 2%-3%) in laboratory-story house. Multiple location sampling, as well as sampling in rooms with and without a miniature source

47

Vessel thermal map real-time system for the JET tokamak R. Felton,2  

E-Print Network [OSTI]

temperature than the formerly installed carbon fiber composite tiles, imposes strict thermal restrictions of the tritium retention levels when compared with the previous carbon fiber composite (CFC)-based wall [1]. JET of international thermonuclear experimental reactor-relevant materials for the plasma facing components (PFCs

48

WEST PROJECT AND OPPORTUNITIES FOR US-  

E-Print Network [OSTI]

/extracted energy in a tokamak (1GJ) Several generations of carbon PFCs designed, manufactured and operated Tore loops 15 MW of HF plasma heating Fuelling systems Diagnostics WEST project ~ few days of ITER operation BECOMES WEST Limiter configuration Carbon Two symmetric divertor coils and supporting structures Plasma

49

Summary of FNST Survey : Thoughts of the Community on progress, concerns, and next steps in FNST  

E-Print Network [OSTI]

Identification of potentially attractive plasma operational modes (hybrid, super-X divertors, lithium wall pacing, RMP, lithium walls) Concerns: Impact of ELMs on PFCs and the difficulty to incorporate not be fabricable by current methods Effects such as corrosion with PbLi may severely limit operating temperature

Abdou, Mohamed

50

Power Handling in ITER: Divertor and Blanket Design and R&D M. Merola 1), D. Loesser 2), R. Raffray 1) on behalf of the ITER Organization, ITER  

E-Print Network [OSTI]

the thermonuclear plasma and cover an area of about 850 m2 . The main function of the divertor is minimizing the thermonuclear plasma. One of the most technically challenging components of the ITER machine are plasma-facing components (PFCs), which directly face the thermonuclear plasma and cover an area of about 850 m2

Raffray, A. René

51

Tritium behavior in eroded dust and debris of plasma-facing A. Hassanein a,*, B. Wiechers b  

E-Print Network [OSTI]

Tritium behavior in eroded dust and debris of plasma-facing materials A. Hassanein a,*, B. Wiechers, Russian Federation Abstract Tritium behavior in plasma-facing components (PFCs) of future tokamak reactors important parameter that in¯uences tritium buildup and release in candidate materials is the eect

Harilal, S. S.

52

Primary Aluminum Production: Climate Policy, Emissions and Costs Jochen Harnisch, Ian Sue Wing, Henry D. Jacoby and Ronald G. Prinn*  

E-Print Network [OSTI]

Primary Aluminum Production: Climate Policy, Emissions and Costs Jochen Harnisch, Ian Sue Wing a significant influence on investment decisions in the production of primary aluminum. This work demonstrates for the baseline years 1990 and 1995. We then present projections for regional emissions of PFCs from the aluminum

53

CECMONITORING|AGUIDETOCECsINTHEBAY Quick Summary  

E-Print Network [OSTI]

). At the same time, it was also found to be a pervasive con- taminant in human blood in the US (Hansen et al. 2001). As a result, the major US manufacturer of PFCs voluntarily withdrew PFOS and other structurally are not fully understood. ·Research in the Great Lakes and elsewhere suggests that wastewater e uent and urban

54

Disruption, VDE and Runaway Electron Conversion  

E-Print Network [OSTI]

redistribute in-divertor energy Magnetic energy 35 (?) MJ For 6.5 MA, total out to VV Current quench duration 6 burn also have enough thermal and magnetic energy to put in-vessel (PFC) and torus vessel systems -- Global vertical and lateral force on VV, etc. · Thermal loading on PFCs, etc. -- Divertor targets

55

Edgy Science III: From NSF Physics Frontier  

E-Print Network [OSTI]

Edgy Science III: From NSF Physics Frontier Centers NSTA 2010 Philadelphia, PA From brains to the Big Bang, take a crash course in forefront science with the NSF Physics Frontier Centers, including - National Science Foundation (NSF) Physics Frontier Centers (PFCs) · Each Center - Science News - Resources

Collar, Juan I.

56

Measurements of chemical erosion of ATJ graphite by low energy D  

E-Print Network [OSTI]

in plasma facing components (PFCs). Because of their high thermal conductivities, excellent shock resistance. PACS: 34.50.Dy; 52.20.Hv; 52.40.Hf; 79.20.Ã?m; 79.20.Rf Keywords: Carbon-based materials; Chemical problems in the development of commercially viable fusion technology is identification of materials for use

57

A COMPARISON OF LIQUID AND SOLID SURFACE OPTIONS FOR  

E-Print Network [OSTI]

Fast Breeder Fission Reactor Fusion First Wall Fusion Disruption Fusion ELM Rocket Nozzle #12;MAU 4 3 · Disruption mitigation using massive gas puff is demonstrated on some machines · Reduced current decay rate PFM and heat sink ­ Coolant compatibility ­ Most likely He gas cooled ­ Liquid metal PFCs are high

58

GENERAL DYNAMICS Space Systems Division  

E-Print Network [OSTI]

"fusion nuclear engineering problems will be pushed past the retirement and even lifetimes of the individualsnow and other "in-vessel"components such as PFCs. Successin obtainingreactor- grade plasmas and their control can build a much smallerdriven tokamak for the essential and parallel development and testing

59

Laboratories to Explore, Explain VLBACHANDRA  

E-Print Network [OSTI]

Technical Issues Divertor and PFCs Disruptions Vac Vessel Nuclear Heating Remote Handling Incorporate with some new methods of remote participation to improve future workshops. Remote particpants, please send as next step. · NRC Interim Report identified "integrated physics of a self-heated plasma" as one

60

Microscopic Motion of Liquid Metal Plasma Facing Components In A Diverted Plasma  

SciTech Connect (OSTI)

Liquid metal plasma facing components (PFCs) have been identified as an alternative material for fusion plasma experiments. The use of a liquid conductor where significant magnetic fields are present is considered risky, with the possibility of macroscopic fluid motion and possible ejection into the plasma core. Analysis is carried out on thermoelectric magnetohydrodynamic (TEMHD) forces caused by temperature gradients in the liquid-container system itself in addition to scrape-off-layer currents interacting with the PFC from a diverted plasma. Capillary effects at the liquid-container interface will be examined which govern droplet ejection criteria. Stability of the interface is determined using linear stability methods. In addition to application to liquidmetal PFCs, thin film liquidmetal effects have application to current and future devices where off-normal events may liquefy portions of the first wall and other plasma facing components.

Jaworski, M A; Morley, N B; Abrams, T; Kaita, R; Kallman, J; Kugel, H; Majeski, R

2010-09-22T23:59:59.000Z

Note: This page contains sample records for the topic "hfcs perfluorocarbons pfcs" 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

Liquid Metal Walls, Lithium, And Low Recycling Boundary Conditions In Tokamaks  

SciTech Connect (OSTI)

At present, the only solid material believed to be a viable option for plasma-facing components (PFCs) in a fusion reactor is tungsten. Operated at the lower temperatures typical of present-day fusion experiments, tungsten is known to suffer from surface degradation during long-term exposure to helium-containing plasmas, leading to reduced thermal conduction to the bulk, and enhanced erosion. Existing alloys are also quite brittle at temperatures under 700oC. However, at a sufficiently high operating temperature (700 - 1000 oC), tungsten is selfannealing and it is expected that surface damage will be reduced to the point where tungsten PFCs will have an acceptable lifetime in a reactor environment. The existence of only one potentially viable option for solid PFCs, though, constitutes one of the most significant restrictions on design space for DEMO and follow-on fusion reactors. In contrast, there are several candidates for liquid metal-based PFCs, including gallium, tin, lithium, and tin-lithium eutectics. We will discuss options for liquid metal walls in tokamaks, looking at both high and low recycling materials. We will then focus in particular on one of the candidate liquids, lithium. Lithium is known to have a high chemical affinity for hydrogen, and has been shown in test stands1 and fusion experiments2,3 to produce a low recycling surface, especially when liquid. Because it is also low-Z and is usable in a tokamak over a reasonable temperature range (200 - 400 oC), it has been now been used as a PFC in several confinement experiments (TFTR, T11- M, CDX-U, NSTX, FTU, and TJ-II), with favorable results. The consequences of substituting low recycling walls for the traditional high recycling variety on tokamak equilibria are very extensive. We will discuss some of the expected modifications, briefly reviewing experimental results, and comparing the results to expectations.

R. Majeski

2010-01-15T23:59:59.000Z

62

Liquid Metal Walls, Lithium, And Low Recycling Boundary Conditions In Tokamaks  

SciTech Connect (OSTI)

At present, the only solid material believed to be a viable option for plasma-facing components (PFCs) in a fusion reactor is tungsten. Operated at the lower temperatures typical of present-day fusion experiments, tungsten is known to suffer from surface degradation during long-term exposure to helium-containing plasmas, leading to reduced thermal conduction to the bulk, and enhanced erosion. Existing alloys are also quite brittle at temperatures under 700 deg. C. However, at a sufficiently high operating temperature (700 - 1000 deg. C), tungsten is self-annealing and it is expected that surface damage will be reduced to the point where tungsten PFCs will have an acceptable lifetime in a reactor environment.The existence of only one potentially viable option for solid PFCs, though, constitutes one of the most significant restrictions on design space for DEMO and follow-on fusion reactors. In contrast, there are several candidates for liquid metal-based PFCs, including gallium, tin, lithium, and tin-lithium eutectics. We will discuss options for liquid metal walls in tokamaks, looking at both high and low recycling materials. We will then focus in particular on one of the candidate liquids, lithium.Lithium is known to have a high chemical affinity for hydrogen, and has been shown in test stands and fusion experiments to produce a low recycling surface, especially when liquid. Because it is also low-Z and is usable in a tokamak over a reasonable temperature range (200 - 400 deg. C), it has been now been used as a PFC in several confinement experiments (TFTR, T11-M, CDX-U, NSTX, FTU, and TJ-II), with favorable results. The consequences of substituting low recycling walls for the traditional high recycling variety on tokamak equilibria are very extensive. We will discuss some of the expected modifications, briefly reviewing experimental results, and comparing the results to expectations.

Majeski, R. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States)

2010-05-20T23:59:59.000Z

63

Plasma-materials interaction results at Sandia National Laboratories.  

SciTech Connect (OSTI)

Overview of Plasma Materials Interaction (PMI) activities are: (1) Hydrogen diffusion and trapping in metals - (a) Growth of hydrogen precipitates in tungsten PFCs, (b) Temperature dependence of deuterium retention at displacement damage, (c) D retention in W at elevated temperatures; (2) Permeation - (a) Gas driven permeation results for W/Mo/SiC, (b) Plasma-driven permeation test stand for TPE; and (3) Surface studies - (a) H-sensor development, (b) Adsorption of oxygen and hydrogen on beryllium surfaces.

Causey, Rion A.; Wampler, William R. (Sandia National Laboratories, Albuquerque, NM); Buchenauer, Dean A.; Karnesky, Richard A.; Whaley, Josh A.; Cowgill, Donald F.; Kolasinski, Robert D.

2010-08-01T23:59:59.000Z

64

VOL. 65, NO. 3 (SEPTEMBER 2012) P. 245256 Perfluorinated Chemicals in Meromictic Lakes on the Northern Coast  

E-Print Network [OSTI]

revealed the presence of several PFCs in catchment snowpack, inflowing streams, lake water, and the aquatic the lake via streams and flows directly under the lake ice to the ocean. The onset of summer open water lacs méromictiques situés sur la côte nord de l'île d'Ellesmere au Nunavut, et d'évaluer les résultats

Vincent, Warwick F.

65

Overview of the US-Japan collaborative investigation on hydrogen isotope retention in neutron-irradiated and ion-damaged tungsten  

SciTech Connect (OSTI)

Plasma-facing components (PFCs) will be exposed to 14 MeV neutrons from deuterium-tritium (D-T) fusion reactions, and tungsten, a candidate PFC for the divertor in ITER, is expected to receive a neutron dose of 0.7 displacement per atom (dpa) by the end of operation in ITER. The effect of neutron-irradiation damage has been mainly simulated using high-energy ion bombardment. While this prior database of results is quite valuable for understanding the behavior of hydrogen isotopes in PFCs, it does not encompass the full range of effects that must be considered in a practical fusion environment due to short penetration depth, damage gradient, high damage rate, and high PKA energy spectrum of the ion bombardment. In addition, neutrons change the elemental composition via transmutations, and create a high radiation environment inside PFCs, which influence the behavior of hydrogen isotope in PFCs, suggesting the utilization of fission reactors is necessary for neutron irradiation. Therefore, the effort to correlate among high-energy ions, fission neutrons, and fusion neutrons is crucial for accurately estimating tritium retention under a neutron-irradiation environment. Under the framework of the US-Japan TITAN program, tungsten samples (99.99 at. % purity from A.L.M.T. Co.) were irradiated by neutron in the High Flux Isotope Reactor (HFIR), ORNL, at 50 and 300C to 0.025, 0.3, and 1.2 dpa, and the investigation of deuterium retention in neutron-irradiation was performed in the INL Tritium Plasma Experiment (TPE), the unique high-flux linear plasma facility that can handle tritium, beryllium and activated materials. This paper reports the recent results from the comparison of ion-damaged tungsten via various ion species (2.8 MeV Fe2+, 20 MeV W2+, and 700 keV H-) with that from neutron-irradiated tungsten to identify the similarities and differences among them.

Masashi Shimada; Y. Hatano; Y. Oya; T. Oda; M. Hara; G. Cao; M. Kobayashi; M. Sokolov; H. Watanabe; B. Tyburska; Y. Ueda; P. Calderoni

2011-09-01T23:59:59.000Z

66

2D surface temperature measurement of plasma facing components with modulated active pyrometry  

SciTech Connect (OSTI)

In nuclear fusion devices, such as Tore Supra, the plasma facing components (PFC) are in carbon. Such components are exposed to very high heat flux and the surface temperature measurement is mandatory for the safety of the device and also for efficient plasma scenario development. Besides this measurement is essential to evaluate these heat fluxes for a better knowledge of the physics of plasma-wall interaction, it is also required to monitor the fatigue of PFCs. Infrared system (IR) is used to manage to measure surface temperature in real time. For carbon PFCs, the emissivity is high and known (? ? 0.8), therefore the contribution of the reflected flux from environment and collected by the IR cameras can be neglected. However, the future tokamaks such as WEST and ITER will be equipped with PFCs in metal (W and Be/W, respectively) with low and variable emissivities (? ? 0.1–0.4). Consequently, the reflected flux will contribute significantly in the collected flux by IR camera. The modulated active pyrometry, using a bicolor camera, proposed in this paper allows a 2D surface temperature measurement independently of the reflected fluxes and the emissivity. Experimental results with Tungsten sample are reported and compared with simultaneous measurement performed with classical pyrometry (monochromatic and bichromatic) with and without reflective flux demonstrating the efficiency of this method for surface temperature measurement independently of the reflected flux and the emissivity.

Amiel, S.; Loarer, T.; Pocheau, C.; Roche, H.; Gauthier, E.; Aumeunier, M.-H.; Courtois, X.; Jouve, M.; Balorin, C.; Moncada, V. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Le Niliot, C.; Rigollet, F. [Aix-Marseille Univ, IUSTI, UMR CNRS 7343, F-13453 Marseille (France)

2014-10-15T23:59:59.000Z

67

Chemical and thermal stability of refrigerant-lubricant mixtures with metals  

SciTech Connect (OSTI)

This report presents the results of a sealed tube stability study on twenty-one refrigerant-lubricant mixtures selected from the following groupings: HFCs R-32, R-125, R-134, R-134a, R-143a, and R-152a with one or more lubricants selected from among three pentaerythritol esters and three polyalkylene glycols. All lubricants were carefully predried to 25 ppm or less moisture content. HCFCs R-22, R-123, R-124, and R-142b, as well as CFC R-11, with one or more lubricants selected from among two mineral oils and one alkylbenzene fluid. Bach test mixture was aged at three temperature levels.

Huttenlocher, D.F.

1992-10-09T23:59:59.000Z

68

Chemical and thermal stability of refrigerant-lubricant mixtures with metals. Final report  

SciTech Connect (OSTI)

This report presents the results of a sealed tube stability study on twenty-one refrigerant-lubricant mixtures selected from the following groupings: HFCs R-32, R-125, R-134, R-134a, R-143a, and R-152a with one or more lubricants selected from among three pentaerythritol esters and three polyalkylene glycols. All lubricants were carefully predried to 25 ppm or less moisture content. HCFCs R-22, R-123, R-124, and R-142b, as well as CFC R-11, with one or more lubricants selected from among two mineral oils and one alkylbenzene fluid. Bach test mixture was aged at three temperature levels.

Huttenlocher, D.F.

1992-10-09T23:59:59.000Z

69

FINAL REPORT: EDDY-COVARIANCE FLUX TOWER AND TRACER TECHNOLOGY SUPPORT FOR THE UNIVERSITY OF GEORGIA PROPOSAL: FROM TOWER TO PIXEL: INTEGRATION OF PATCH-SIZE NEE USING EXPERIMENTAL MODELING FOOTPRINT ANALYSIS.  

SciTech Connect (OSTI)

Brookhaven National Laboratory has been funded since October of 2000 to provide assistance to the University of Georgia in conducting footprint analyses of individual towers based on meteorology and trace gas measurements. Brookhaven researchers conducted air flow measurements using perfluorocarbon tracers and meteorological instrumentation for three experimental campaigns at an AmeriFlux research site maintained by Dr. Monique Leclerc near Gainesville, FL. In addition, BNL provided assistance with remote data collection and distribution from remote field sites operated by Dr. John Hom of the US Forest Service in the Pine Barrens of New Jersey and at FACE research sites in North Carolina and Wisconsin.

LEWIN,K.F.; NAGY, J.; WATSON, T.B.

2007-09-01T23:59:59.000Z

70

Method for inducing hypothermia  

DOE Patents [OSTI]

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B. (Chicago, IL); Hoek, Terry Vanden (Chicago, IL); Kasza, Kenneth E. (Palos Park, IL)

2008-09-09T23:59:59.000Z

71

Method for inducing hypothermia  

DOE Patents [OSTI]

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B. (Chicago, IL); Hoek, Terry Vanden (Chicago, IL); Kasza, Kenneth E. (Palos Park, IL)

2003-04-15T23:59:59.000Z

72

Method for inducing hypothermia  

DOE Patents [OSTI]

Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

2005-11-08T23:59:59.000Z

73

First operation with the JET International Thermonuclear Experimental Reactor-like wall  

SciTech Connect (OSTI)

To consolidate International Thermonuclear Experimental Reactor (ITER) design choices and prepare for its operation, Joint European Torus (JET) has implemented ITER's plasma facing materials, namely, Be for the main wall and W in the divertor. In addition, protection systems, diagnostics, and the vertical stability control were upgraded and the heating capability of the neutral beams was increased to over 30 MW. First results confirm the expected benefits and the limitations of all metal plasma facing components (PFCs) but also yield understanding of operational issues directly relating to ITER. H-retention is lower by at least a factor of 10 in all operational scenarios compared to that with C PFCs. The lower C content (? factor 10) has led to much lower radiation during the plasma burn-through phase eliminating breakdown failures. Similarly, the intrinsic radiation observed during disruptions is very low, leading to high power loads and to a slow current quench. Massive gas injection using a D{sub 2}/Ar mixture restores levels of radiation and vessel forces similar to those of mitigated disruptions with the C wall. Dedicated L-H transition experiments indicate a 30% power threshold reduction, a distinct minimum density, and a pronounced shape dependence. The L-mode density limit was found to be up to 30% higher than for C allowing stable detached divertor operation over a larger density range. Stable H-modes as well as the hybrid scenario could be re-established only when using gas puff levels of a few 10{sup 21} es{sup ?1}. On average, the confinement is lower with the new PFCs, but nevertheless, H factors up to 1 (H-Mode) and 1.3 (at ?{sub N}?3, hybrids) have been achieved with W concentrations well below the maximum acceptable level.

Neu, R. [EFDA-CSU, Boltzmannstr. 2, 85748 Garching (Germany) [EFDA-CSU, Boltzmannstr. 2, 85748 Garching (Germany); Max-Planck-Institut für Plasmaphysik, Euratom Association, Boltzmannstr. 2, 85748 Garching (Germany); Arnoux, G.; Beurskens, M.; Challis, C.; Giroud, C.; Lomas, P.; Maddison, G.; Matthews, G.; Mayoral, M.-L.; Meigs, A.; Rimini, F. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)] [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Bobkov, V.; Dux, R.; Hobirk, J.; Lang, P.; Maggi, C.; Pütterich, T.; Sertoli, M.; Sieglin, B. [Max-Planck-Institut für Plasmaphysik, Euratom Association, Boltzmannstr. 2, 85748 Garching (Germany)] [Max-Planck-Institut für Plasmaphysik, Euratom Association, Boltzmannstr. 2, 85748 Garching (Germany); Brezinsek, S. [IEK-4, Association EURATOM/Forschungszentrum Jülich GmbH, Jülich 52425 (Germany)] [IEK-4, Association EURATOM/Forschungszentrum Jülich GmbH, Jülich 52425 (Germany); and others

2013-05-15T23:59:59.000Z

74

Synopsis of residential refrigerator/freezer alternative refrigerants evaluation  

SciTech Connect (OSTI)

The experimental testing on residential refrigerator/freezers (R/Fs) is summarized in this paper. R/F testing focused on two areas: alternative refrigerants and equipment configurations. The refrigerants evaluated consisted of single components, azeotropes, and zeotropes derived from hydrofluorocarbons (HFCs) and hydrocarbons (HCs). These refrigerants were evaluated in conventional and unconventional R/F designs. Major and minor design modifications were studied. Minor modifications consisted of various capillary tube lengths, door insulations, and compressors, while major modifications included two-evaporator and two-cycle R/F systems. Results obtained from testing the two-cycle system will be discussed in a later paper. This paper presents the experimental results of alternative technologies evaluated as replacements for ozone depleting chemicals.

Baskin, E. [Environmental Protection Agency, Research Triangle Park, NC (United States)

1998-12-31T23:59:59.000Z

75

Diagnostic options for radiative divertor feedback control on NSTX-U  

SciTech Connect (OSTI)

A radiative divertor technique is used in present tokamak experiments and planned for ITER to mitigate high heat loads on divertor plasma-facing components (PFCs) to prevent excessive material erosion and thermal damage. In NSTX, a large spherical tokamak with lithium-coated graphite PFCs and high divertor heat flux (q{sub peak} Less-Than-Or-Slanted-Equal-To 15 MW/m{sup 2}), radiative divertor experiments have demonstrated a significant reduction of divertor peak heat flux simultaneously with good core H-mode confinement using pre-programmed D{sub 2} or CD{sub 4} gas injections. In this work diagnostic options for a new real-time feedback control system for active radiative divertor detachment control in NSTX-U, where steady-state peak divertor heat fluxes are projected to reach 20-30 MW/m{sup 2}, are discussed. Based on the NSTX divertor detachment measurements and analysis, the control diagnostic signals available for NSTX-U include divertor radiated power, neutral pressure, spectroscopic deuterium recombination signatures, infrared thermography of PFC surfaces, and thermoelectric scrape-off layer current. In addition, spectroscopic 'security' monitoring of possible confinement or pedestal degradation is recommended. These signals would be implemented in a digital plasma control system to manage the divertor detachment process via an actuator (impurity gas seeding rate).

Soukhanovskii, V. A.; McLean, A. G. [Lawrence Livermore National Laboratory, Livermore, California, 94550 (United States); Gerhardt, S. P.; Kaita, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Raman, R. [University of Washington, Seattle, Washington 98195 (United States)

2012-10-15T23:59:59.000Z

76

Tritium plasma experiment: Parameters and potentials for fusion plasma-wall interaction studies  

SciTech Connect (OSTI)

The tritium plasma experiment (TPE) is a unique facility devoted to experiments on the behavior of deuterium/tritium in toxic (e.g., beryllium) and radioactive materials for fusion plasma-wall interaction studies. A Langmuir probe was added to the system to characterize the plasma conditions in TPE. With this new diagnostic, we found the achievable electron temperature ranged from 5.0 to 10.0 eV, the electron density varied from 5.0 x 10{sup 16} to 2.5 x 10{sup 18} m{sup -3}, and the ion flux density varied between 5.0 x 10{sup 20} to 2.5 x 10{sup 22} m{sup -2} s{sup -1} along the centerline of the plasma. A comparison of these plasma parameters with the conditions expected for the plasma facing components (PFCs) in ITER shows that TPE is capable of achieving most ({approx}800 m{sup 2} of 850 m{sup 2} total PFCs area) of the expected ion flux density and electron density conditions.

Shimada, Masashi; Sharpe, J. Phillip [Fusion Safety Program, Idaho National Laboratory, Idaho Falls, Idaho 83415 (United States); Kolasinski, Robert D.; Causey, Rion A. [Hydrogen and Metallurgical Science Department, Sandia National Laboratories, Livermore, California 94551 (United States)

2011-08-15T23:59:59.000Z

77

Demonstration of High Efficiency Elastocaloric Cooling with Large Delta- T Using NiTi Wires  

SciTech Connect (OSTI)

Vapor compression (VC) is by far the most dominant technology for meeting all cooling and refrigeration needs around the world. It is a mature technology with the efficiency of modern compressors approaching the theoretical limit, but its envi-ronmental footprint remains a global problem. VC refrigerants such as hydrochlo-roflurocarbons (HCFCs) and hydrofluorocarbons (HFCs) are a significant source of green house gas (GHG) emissions, and their global warming potential (GWP) is as high as 1000 times that of CO2. It is expected that building space cooling and re-frigeration alone will amount to {approx} 5% of primary energy consumption and {approx}5% of all CO2 emission in U.S. in 2030 . As such, there is an urgent need to develop an al-ternative high-efficiency cooling technology that is affordable and environmentally friendly. Among the proposed candidates, magnetocaloric cooling (MC) is currently received a lot of attention because of its high efficiency. However, MC is inherently expensive because of the requirement of large magnetic field and rare earth materi-als. Here, we demonstrate an entirely new type of solid-state cooling mechanism based on the latent heat of reversible martensitic transformation. We call it elasto-caloric cooling (EC) after the superelastic transformation of austenite it utilizes. The solid-state refrigerant of EC is cost-effective, and it completely eliminates the use of any refrigerants including HCFCs/HFCs. We show that the COP (coefficient of per-formance) of a jugular EC with optimized materials can be as high as > 10 with measured {Delta}T of 17 C.

Cui, Jun; Wu, Yiming; Muehlbauer, Jan; Hwang, Yunho; Radermacher, Reinhard; Fackler, Sean; Wuttig, Manfred; Takeuchi, Ichiro

2012-08-01T23:59:59.000Z

78

Energy and global warming impacts of HFC refrigerants and emerging technologies: TEWI-III  

SciTech Connect (OSTI)

The use of hydrofluorocarbons (BFCs) which were developed as alternative refrigerants and insulating foam blowing agents to replace chlorofluorocarbons (CFCs) is now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants and blowing agents on global warming. A Total Equivalent Warming Impact (TEWI) assessment analyzes the environmental affects of these halogenated working fluids in energy consuming applications by combining a direct effect resulting from the inadvertent release of HFCs to the atmosphere with an indirect effect resulting from the combustion of fossil fuels needed to provide the energy to operate equipment using these compounds as working fluids. TEWI is a more balanced measure of environmental impact because it is not based solely on the global warming potential (GWP) of the working fluid. It also shows the environmental benefit of efficient technologies that result in less CO{sub 2} generation and eventual emission to the earth`s atmosphere. The goal of TEWI is to assess total global warming impact of all the gases released to the atmosphere, including CO{sub 2} emissions from energy conversion. Alternative chemicals and technologies have been proposed as substitutes for HFCs in the vapor-compression cycle for refrigeration and air conditioning and for polymer foams in appliance and building insulations which claim substantial environmental benefits. Among these alternatives are: (1) Hydrocarbon (HC) refrigerants and blowing agents which have zero ozone depleting potential and a negligible global warming potential, (2) CO{sub 2} as a refrigerant and blowing agent, (3) Ammonia (NH{sub 3}) vapor compression systems, (4) Absorption chiller and heat pumping cycles using ammonia/water or lithium bromide/water, and (5) Evacuated panel insulations. This paper summarizes major results and conclusions of the detailed final report on the TEWI-111 study.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1997-06-01T23:59:59.000Z

79

Measurement of large strains in ropes using plastic optical fibers  

DOE Patents [OSTI]

A method for the direct measurement of large strains in ropes in situ using a plastic optical fiber, for example, perfluorocarbon or polymethyl methacrylate and Optical Time-Domain Reflectometer or other light time-of-flight measurement instrumentation. Protective sheaths and guides are incorporated to protect the plastic optical fiber. In one embodiment, a small rope is braided around the plastic optical fiber to impose lateral compressive forces to restrain the plastic optical fiber from slipping and thus experience the same strain as the rope. Methods are described for making reflective interfaces along the length of the plastic optical fiber and to provide the capability to measure strain within discrete segments of the rope. Interpretation of the data allows one to calculate the accumulated strain at any point in time and to determine if the rope has experienced local damage.

Williams, Jerry Gene; Smith, David Barton; Muhs, Jeffrey David

2006-02-14T23:59:59.000Z

80

Electrolytic production of neodymium without perfluorinated carbon compounds on the offgases  

DOE Patents [OSTI]

A method is described for producing neodymium in an electrolytic cell without formation of perfluorinated carbon gases (PFCs), the method comprising the steps of providing an electrolyte in the electrolytic cell and providing an anode in an anode region of the electrolyte and providing a cathode in a cathode region of the electrolytic cell. Dissolving an oxygen-containing neodymium compound in the electrolyte in the anode region and maintaining a more intense electrolyte circulation in the anode region than in the cathode region. Passing an electrolytic current between said anode and said cathode and depositing neodymium metal at the cathode, preventing the formation of perfluorinated carbon gases by limiting anode over voltage. 4 figs.

Keller, R.; Larimer, K.T.

1998-09-22T23:59:59.000Z

Note: This page contains sample records for the topic "hfcs perfluorocarbons pfcs" 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

New field programmable gate array-based image-oriented acquisition and real-time processing applied to plasma facing component thermal monitoring  

SciTech Connect (OSTI)

During operation of present fusion devices, the plasma facing components (PFCs) are exposed to high heat fluxes. Understanding and preventing overheating of these components during long pulse discharges is a crucial safety issue for future devices like ITER. Infrared digital cameras interfaced with complex optical systems have become a routine diagnostic to measure surface temperatures in many magnetic fusion devices. Due to the complexity of the observed scenes and the large amount of data produced, the use of high computational performance hardware for real-time image processing is then mandatory to avoid PFC damages. At Tore Supra, we have recently made a major upgrade of our real-time infrared image acquisition and processing board by the use of a new field programmable gate array (FPGA) optimized for image processing. This paper describes the new possibilities offered by this board in terms of image calibration and image interpretation (abnormal thermal events detection) compared to the previous system.

Martin, V. [Pulsar Team-Project, INRIA Sophia Antipolis, Sophia Antipolis F-06902 (France); Dunand, G.; Moncada, V. [Sophia Conseil Company, Sophia Antipolis F-06560 (France); Jouve, M.; Travere, J.-M. [CEA, IRFM, Saint-Paul-Lez-Durance F-13108 (France)

2010-10-15T23:59:59.000Z

82

Lithium Wall Conditioning And Surface Dust Detection On NSTX  

SciTech Connect (OSTI)

Lithium evaporation onto NSTX plasma facing components (PFC) has resulted in improved energy confinement, and reductions in the number and amplitude of edge-localized modes (ELMs) up to the point of complete ELM suppression. The associated PFC surface chemistry has been investigated with a novel plasma material interface probe connected to an in-vacuo surface analysis station. Analysis has demonstrated that binding of D atoms to the polycrystalline graphite material of the PFCs is fundamentally changed by lithium - in particular deuterium atoms become weakly bonded near lithium atoms themselves bound to either oxygen or the carbon from the underlying material. Surface dust inside NSTX has been detected in real-time using a highly sensitive electrostatic dust detector. In a separate experiment, electrostatic removal of dust via three concentric spiral-shaped electrodes covered by a dielectric and driven by a high voltage 3-phase waveform was evaluated for potential application to fusion reactors

Skinner, C H; Bell, M G; Friesen, F.Q.L.; Heim, B; Jaworski, M A; Kugel, H; Maingi, R; Rais, B

2011-05-23T23:59:59.000Z

83

Theory and models of material erosion and lifetime during plasma instabilities in a tokamak environment.  

SciTech Connect (OSTI)

Surface and structural damage to plasma-facing components (PFCs) due to the frequent loss of plasma confinement remains a serious problem for the tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination. Surface damage consists of vaporization, spallation, and liquid splatter of metallic materials. Structural damage includes large temperature increases in structural materials and at the interfaces between surface coatings and structural members. To evaluate the lifetimes of plasma-facing materials and nearby components and to predict the various forms of damage that they experience, comprehensive models (contained in the HEIGHTS computer simulation package) are developed, integrated self-consistently, and enhanced. Splashing mechanisms such as bubble boiling and various liquid magnetohydrodynamic instabilities and brittle destruction mechanisms of nonmelting materials are being examined. The design requirements and implications of plasma-facing and nearby components are discussed, along with recommendations to mitigate and reduce the effects of plasma instabilities on reactor components.

Hassanein, A.; Konkashbaev, I.

1999-11-08T23:59:59.000Z

84

Plasma/liquid metal interactions during tokamak operation.  

SciTech Connect (OSTI)

One of the critical technological challenges of future tokamak fusion devices is the ability for plasma-facing components to handle both normal and abnormal plasma/surface interaction events that compromise their lifetime and operation of the machine. Under normal operation plasma/surface interactions that are important include: sputtering, particle implantation and recycling, He pumping and ELM (edge localized modes)-induced erosion. In abnormal or off-normal operation: disruptions and vertical displacement events (VDEs) are important. To extend PFC lifetime under these conditions, liquid-metals have been considered as candidate PFCs (Plasma-Facing Components), including: liquid lithium, tin-lithium, gallium and tin. Liquid lithium has been measured to have nonlinear increase of physical sputtering with rise in temperature. Such increase can be a result of exposure to ELM-level particle fluxes. The significant increase in particle flux to the divertor and nearby PFCs can enhance sputtering erosion by an order of magnitude or more. In addition from the standpoint of hydrogen recycling and helium pumping liquid lithium appears to be a good candidate plasma-facing material (PFM). Advanced designs of first wall and divertor systems propose the application of liquid-metals as an alternate PFC to contend with high-heat flux constraints of large-scale tokamak devices. Additional issues include PFC operation under disruptions and long temporal instabilities such as VDEs. A comprehensive two-fluid model is developed to integrate core and SOL (scrape-off layer) parameters during ELMs with PFC surface evolution using the HEIGHTS package. Special emphasis is made on the application of lithium as a candidate plasma-facing liquid-metal.

Hassanein, A.; Allain, J. P.; Insepov, Z.; Konkashbaev, I.; Energy Technology

2005-04-01T23:59:59.000Z

85

Plasma/Liquid-Metal Interactions During Tokamak Operation  

SciTech Connect (OSTI)

One of the critical technological challenges of future tokamak fusion devices is the ability for plasma-facing components to handle both normal and abnormal plasma/surface interaction events that compromise their lifetime and operation of the machine. Under normal operation plasma/surface interactions that are important include: sputtering, particle implantation and recycling, He pumping and ELM (edge localized modes)-induced erosion. In abnormal or off-normal operation: disruptions and vertical displacement events (VDEs) are important. To extend PFC lifetime under these conditions, liquid-metals have been considered as candidate PFCs (Plasma-Facing Components), including: liquid lithium, tin-lithium, gallium and tin.Liquid lithium has been measured to have nonlinear increase of physical sputtering with rise in temperature. Such increase can be a result of exposure to ELM-level particle fluxes. The significant increase in particle flux to the divertor and nearby PFCs can enhance sputtering erosion by an order of magnitude or more. In addition from the standpoint of hydrogen recycling and helium pumping liquid lithium appears to be a good candidate plasma-facing material (PFM). Advanced designs of first wall and divertor systems propose the application of liquid-metals as an alternate PFC to contend with high-heat flux constraints of large-scale tokamak devices. Additional issues include PFC operation under disruptions and long temporal instabilities such as VDEs. A comprehensive two-fluid model is developed to integrate core and SOL (scrape-off layer) parameters during ELMs with PFC surface evolution using the HEIGHTS package. Special emphasis is made on the application of lithium as a candidate plasma-facing liquid-metal.

Hassanein, A.; Allain, J.P.; Insepov, Z.; Konkashbaev, I. [Argonne National Laboratory (United States)

2005-04-15T23:59:59.000Z

86

Final report on activities and findings under DOE grant “Interactive Photochemistry in Earth System Models to Assess Uncertainty in Ozone and Greenhouse Gases”  

SciTech Connect (OSTI)

Atmospheric chemistry controls the abundances and hence climate forcing of important greenhouse gases including N2O, CH4, HFCs, CFCs, and O3. Attributing climate change to human activities requires, at a minimum, accurate models of the chemistry and circulation of the atmosphere that relate emissions to abundances. This DOE-funded research provided realistic, yet computationally optimized and affordable, photochemical modules to the Community Earth System Model (CESM) that augment the CESM capability to explore the uncertainty in future stratospheric-tropospheric ozone, stratospheric circulation, and thus the lifetimes of chemically controlled greenhouse gases from climate simulations. To this end, we have successfully implemented Fast-J (radiation algorithm determining key chemical photolysis rates) and Linoz v3.0 (linearized photochemistry for interactive O3, N2O, NOy and CH4) packages in LLNL-CESM and for the first time demonstrated how change in O2 photolysis rate within its uncertainty range can significantly impact on the stratospheric climate and ozone abundances. From the UCI side, this proposal also helped LLNL develop a CAM-Superfast Chemistry model that was implemented for the IPCC AR5 and contributed chemical-climate simulations to CMIP5.

Prather, Michael J. [UCI

2014-11-07T23:59:59.000Z

87

Global warming implications of non-fluorocarbon technologies as CFC replacements  

SciTech Connect (OSTI)

Many technologies could be developed for use in place of conventional compression systems for refrigeration and air conditioning. Comparisons of the global warming impacts using TEWI (Total Equivalent Warming Impact) can be used to identify alternatives that have the potential for lower environmental impacts than electric-driven vapor compression systems using HCFCs and HFCs. Some options, such as secondary heat transfer loops in commercial refrigeration systems to reduce refrigerant charge and emission rates, could be useful in reducing the losses of refrigerants to the atmosphere. Use of ammonia instead of a fluorocarbon in a system with a secondary loop offers only a small potential for decreasing TEWI, and this may not warrant the increased complexity and risks of using ammonia in a retail sales environment. A few technologies, such as adsorption heat pumps, have efficiency levels that show reduced TEWI levels compared to conventional and state of the art compression systems, and further development could lead to an even more favorable comparison. Health and safety risks of the alternative technologies and the materials they employ must also be considered.

Fischer, S.K.; Tomlinson, J.J.

1993-12-31T23:59:59.000Z

88

Global warming and end-use efficiency implications of replacing CFCs  

SciTech Connect (OSTI)

The direct contribution of CFCs to calculated global warming has been recognized for some time. As a result of the international agreement to phase out CFCs due to stratospheric ozone and the ensuing search for suitable alternatives, there has recently been increased attention on the DIRECT global warming potential (GWP) of the fluorocarbon alternatives as greenhouse gases. However, to date there has been little focus on the INDIRECT global warming effect arising from end-use efficiency changes and associated CO{sub 2} emissions. A study being conducted at Oak Ridge National Laboratory (ORNL) addresses this combined or total global warming impact of viable options to replace CFCs in their major energy-related applications. This paper reviews selected results for air-conditioning, refrigeration, and heat pump applications. The analysis indicates that the CFC user industries have made substantial progress in approaching near-equal energy efficiency with the HCFC/HFC alternative refrigerants. The findings also bring into question the relative importance of the DIRECT (chemical-related) effect in many applications. Replacing CFCs is an important step in reducing the total global warming impact, and at present the HCFC and HFCS appear to offer the best efficiency and lowest total impact of options available in the relatively short time period required for the transition away from CFCs.

Fairchild, P.D.; Fischer, S.K.

1991-12-31T23:59:59.000Z

89

Energy and global warming impacts of next generation refrigeration and air conditioning technologies  

SciTech Connect (OSTI)

Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1996-10-01T23:59:59.000Z

90

Lithium As Plasma Facing Component for Magnetic Fusion Research  

SciTech Connect (OSTI)

The use of lithium in magnetic fusion confinement experiments started in the 1990's in order to improve tokamak plasma performance as a low-recycling plasma-facing component (PFC). Lithium is the lightest alkali metal and it is highly chemically reactive with relevant ion species in fusion plasmas including hydrogen, deuterium, tritium, carbon, and oxygen. Because of the reactive properties, lithium can provide strong pumping for those ions. It was indeed a spectacular success in TFTR where a very small amount (~ 0.02 gram) of lithium coating of the PFCs resulted in the fusion power output to improve by nearly a factor of two. The plasma confinement also improved by a factor of two. This success was attributed to the reduced recycling of cold gas surrounding the fusion plasma due to highly reactive lithium on the wall. The plasma confinement and performance improvements have since been confirmed in a large number of fusion devices with various magnetic configurations including CDX-U/LTX (US), CPD (Japan), HT-7 (China), EAST (China), FTU (Italy), NSTX (US), T-10, T-11M (Russia), TJ-II (Spain), and RFX (Italy). Additionally, lithium was shown to broaden the plasma pressure profile in NSTX, which is advantageous in achieving high performance H-mode operation for tokamak reactors. It is also noted that even with significant applications (up to 1,000 grams in NSTX) of lithium on PFCs, very little contamination (< 0.1%) of lithium fraction in main fusion plasma core was observed even during high confinement modes. The lithium therefore appears to be a highly desirable material to be used as a plasma PFC material from the magnetic fusion plasma performance and operational point of view. An exciting development in recent years is the growing realization of lithium as a potential solution to solve the exceptionally challenging need to handle the fusion reactor divertor heat flux, which could reach 60 MW/m2 . By placing the liquid lithium (LL) surface in the path of the main divertor heat flux (divertor strike point), the lithium is evaporated from the surface. The evaporated lithium is quickly ionized by the plasma and the ionized lithium ions can provide a strongly radiative layer of plasma ("radiative mantle"), thus could significantly reduce the heat flux to the divertor strike point surfaces, thus protecting the divertor surface. The protective effects of LL have been observed in many experiments and test stands. As a possible reactor divertor candidate, a closed LL divertor system is described. Finally, it is noted that the lithium applications as a PFC can be quite flexible and broad. The lithium application should be quite compatible with various divertor configurations, and it can be also applied to protecting the presently envisioned tungsten based solid PFC surfaces such as the ones for ITER. Lithium based PFCs therefore have the exciting prospect of providing a cost effective flexible means to improve the fusion reactor performance, while providing a practical solution to the highly challenging divertor heat handling issue confronting the steadystate magnetic fusion reactors.

Masayuki Ono

2012-09-10T23:59:59.000Z

91

FLORIDA TOWER FOOTPRINT EXPERIMENTS  

SciTech Connect (OSTI)

The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

2007-01-01T23:59:59.000Z

92

Uncertainties in Air Exchange using Continuous-Injection, Long-Term Sampling Tracer-Gas Methods  

SciTech Connect (OSTI)

The PerFluorocarbon Tracer (PFT) method is a low-cost approach commonly used for measuring air exchange in buildings using tracer gases. It is a specific application of the more general Continuous-Injection, Long-Term Sampling (CILTS) method. The technique is widely used but there has been little work on understanding the uncertainties (both precision and bias) associated with its use, particularly given that it is typically deployed by untrained or lightly trained people to minimize experimental costs. In this article we will conduct a first-principles error analysis to estimate the uncertainties and then compare that analysis to CILTS measurements that were over-sampled, through the use of multiple tracers and emitter and sampler distribution patterns, in three houses. We find that the CILTS method can have an overall uncertainty of 10-15percent in ideal circumstances, but that even in highly controlled field experiments done by trained experimenters expected uncertainties are about 20percent. In addition, there are many field conditions (such as open windows) where CILTS is not likely to provide any quantitative data. Even avoiding the worst situations of assumption violations CILTS should be considered as having a something like a ?factor of two? uncertainty for the broad field trials that it is typically used in. We provide guidance on how to deploy CILTS and design the experiment to minimize uncertainties.

Sherman, Max H.; Walker, Iain S.; Lunden, Melissa M.

2013-12-01T23:59:59.000Z

93

TheU-Tube: A Novel System for Acquiring Borehole Fluid Samplesfrom a Deep Geologic CO2 Sequestration Experiment  

SciTech Connect (OSTI)

A novel system has been deployed to obtain geochemical samples of water and gas, at in situ pressure, during a geologic CO2 sequestration experiment conducted in the Frio brine aquifer in Liberty County, Texas. Project goals required high-frequency recovery of representative and uncontaminated aliquots of a rapidly changing two-phase (supercritical CO2-brine) fluid from 1.5 km depth. The datasets collected, using both the liquid and gas portions of the downhole samples, provide insights into the coupled hydro-geochemical issues affecting CO2 sequestration in brine-filled formations. While the basic premise underlying the U-Tube sampler is not new, the system is unique because careful consideration was given to the processing of the recovered two-phase fluids. In particular, strain gauges mounted beneath the high-pressure surface sample cylinders measured the ratio of recovered brine to supercritical CO2. A quadrupole mass spectrometer provided real-time gas analysis for perfluorocarbon and noble gas tracers that were injected along with the CO2. The U-Tube successfully acquired frequent samples, facilitating accurate delineation of the arrival of the CO2 plume, and on-site analysis revealed rapid changes in geochemical conditions.

Freifeld, Barry M.; Trautz, Robert C.; Kharaka, Yousif K.; Phelps, Tommy J.; Myer, Larry R.; Hovorka, Susan D.; Collins, Daniel J.

2005-03-17T23:59:59.000Z

94

Taggants, method for forming a taggant, and a method for detecting an object  

DOE Patents [OSTI]

A taggant comprising at least one perfluorocarbon compound surrounded by a polyphosphazene compound. The polyphosphazene compound has the chemical structure: ##STR00001## wherein G.sub.1 and G.sub.2 are pendant groups having different polarities, m is an integer greater than or equal to 100, and each of A and B is independently selected from hydrogen, an alkyl, an alkene, an alkoxide, a polyether, a polythioether, a siloxane, and --X(CH.sub.2).sub.nY.sup.1(CH.sub.2)p.sub.1Y.sup.2(CH.sub.2)p.sub.2 . . . Y.sup.i(CH.sub.2)p.sub.iCH.sub.3, where n ranges from 1 to 6, X and Y are independently selected from oxygen, sulfur, selenium, tellurium, and polonium, and p.sub.1 through p.sub.i range from 1 to 6. Cyclic polyphosphazene compounds lacking the A and B groups are also disclosed, as are methods of forming the taggant and of detecting an object.

Harrup, Mason K. (Idaho Falls, ID); Stewart, Frederick F. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID)

2012-02-28T23:59:59.000Z

95

Characterization and performance of a field aligned ion cyclotron range of frequency antenna in Alcator C-Mod  

SciTech Connect (OSTI)

Ion cyclotron range of frequency (ICRF) heating is expected to provide auxiliary heating for ITER and future fusion reactors where high Z metallic plasma facing components (PFCs) are being considered. Impurity contamination linked to ICRF antenna operation remains a major challenge particularly for devices with high Z metallic PFCs. Here, we report on an experimental investigation to test whether a field aligned (FA) antenna can reduce impurity contamination and impurity sources. We compare the modification of the scrape of layer (SOL) plasma potential of the FA antenna to a conventional, toroidally aligned (TA) antenna, in order to explore the underlying physics governing impurity contamination linked to ICRF heating. The FA antenna is a 4-strap ICRF antenna where the current straps and antenna enclosure sides are perpendicular to the total magnetic field while the Faraday screen rods are parallel to the total magnetic field. In principle, alignment with respect to the total magnetic field minimizes integrated E|| (electric field along a magnetic field line) via symmetry. A finite element method RF antenna model coupled to a cold plasma model verifies that the integrated E|| should be reduced for all antenna phases. Monopole phasing in particular is expected to have the lowest integrated E||. Consistent with expectations, we observed that the impurity contamination and impurity source at the FA antenna are reduced compared to the TA antenna. In both L and H-mode discharges, the radiated power is 20%–30% lower for a FA-antenna heated discharge than a discharge heated with the TA-antennas. However, inconsistent with expectations, we observe RF induced plasma potentials (via gas-puff imaging and emissive probes to be nearly identical for FA and TA antennas when operated in dipole phasing). Moreover, the highest levels of RF-induced plasma potentials are observed using monopole phasing with the FA antenna. Thus, while impurity contamination and sources are indeed reduced with the FA antenna configuration, the mechanism determining the SOL plasma potential in the presence of ICRF and its impact on impurity contamination and sources remains to be understood.

Wukitch, S. J.; Garrett, M. L.; Ochoukov, R.; Terry, J. L.; Hubbard, A.; Labombard, B.; Lau, C.; Lin, Y.; Lipschultz, B.; Miller, D.; Reinke, M. L.; Whyte, D. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)] [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Collaboration: Alcator C-Mod Team

2013-05-15T23:59:59.000Z

96

Defect annealing and thermal desorption of deuterium in low dose HFIR neutron-irradiated tungsten  

SciTech Connect (OSTI)

Accurately estimating tritium retention in plasma facing components (PFCs) and minimizing its uncertainty are key safety issues for licensing future fusion power reactors. D-T fusion reactions produce 14.1 MeV neutrons that activate PFCs and create radiation defects throughout the bulk of the material of these components. Recent studies show that tritium migrates and is trapped in bulk (>> 10 µm) tungsten beyond the detection range of nuclear reaction analysis technique [1-2], and thermal desorption spectroscopy (TDS) technique becomes the only established diagnostic that can reveal hydrogen isotope behavior in in bulk (>> 10 µm) tungsten. Radiation damage and its recovery mechanisms in neutron-irradiated tungsten are still poorly understood, and neutron-irradiation data of tungsten is very limited. In this paper, systematic investigations with repeated plasma exposures and thermal desorption are performed to study defect annealing and thermal desorption of deuterium in low dose neutron-irradiated tungsten. Three tungsten samples (99.99 at. % purity from A.L.M.T. Co., Japan) irradiated at High Flux Isotope Reactor at Oak Ridge National Laboratory were exposed to high flux (ion flux of (0.5-1.0)x1022 m-2s-1 and ion fluence of 1x1026 m-2) deuterium plasma at three different temperatures (100, 200, and 500 °C) in Tritium Plasma Experiment at Idaho National Laboratory. Subsequently, thermal desorption spectroscopy (TDS) was performed with a ramp rate of 10 °C/min up to 900 °C, and the samples were annealed at 900 °C for 0.5 hour. These procedures were repeated three (for 100 and 200 °C samples) and four (for 500 °C sample) times to uncover damage recovery mechanisms and its effects on deuterium behavior. The results show that deuterium retention decreases approximately 90, 75, and 66 % for 100, 200, and 500 °C, respectively after each annealing. When subjected to the same TDS recipe, the desorption temperature shifts from 800 °C to 600 °C after 1st annealing for the sample exposed to TPE at 500 °C. Tritium Migration Analysis Program (TMAP) analysis reveals that the detrapping energy decreases from 1.8 eV to 1.4 eV, indicating the changes in trapping mechanisms. This paper also summarizes deuterium behavior studies in HFIR neutron-irradiated tungsten under US-Japan TITAN program.

Masashi Shimada; M. Hara; T. Otsuka; Y. Oya; Y. Hatano

2014-05-01T23:59:59.000Z

97

The Impact Of Lithium Wall Coatings On NSTX Discharges And The Engineering Of The Lithium Tokamak eXperiment (LTX)  

SciTech Connect (OSTI)

Recent experiments on the National Spherical Torus eXperiment (NSTX) have shown the benefits of solid lithium coatings on carbon PFC's to diverted plasma performance, in both Land H- mode confinement regimes. Better particle control, with decreased inductive flux consumption, and increased electron temperature, ion temperature, energy confinement time, and DD neutron rate were observed. Successive increases in lithium coverage resulted in the complete suppression of ELM activity in H-mode discharges. A liquid lithium divertor (LLD), which will employ the porous molybdenum surface developed for the LTX shell, is being installed on NSTX for the 2010 run period, and will provide comparisons between liquid walls in the Lithium Tokamak eXperiment (LTX) and liquid divertor targets in NSTX. LTX, which recently began operations at the Princeton Plasma Physics Laboratory, is the world's first confinement experiment with full liquid metal plasma-facing components (PFCs). All materials and construction techniques in LTX are compatible with liquid lithium. LTX employs an inner, heated, stainless steel-faced liner or shell, which will be lithium-coated. In order to ensure that lithium adheres to the shell, it is designed to operate at up to 500 - 600 oC to promote wetting of the stainless by the lithium, providing the first hot wall in a tokamak to operate at reactor-relevant temperatures. The engineering of LTX will be discussed.

R. Majeski, H. Kugel and R. Kaita

2010-03-18T23:59:59.000Z

98

Strike Point Control for the National Spherical Torus Experiment (NSTX)  

SciTech Connect (OSTI)

This paper presents the first control algorithm for the inner and outer strike point position for a Spherical Torus (ST) fusion experiment and the performance analysis of the controller. A liquid lithium divertor (LLD) will be installed on NSTX which is believed to provide better pumping than lithium coatings on carbon PFCs. The shape of the plasma dictates the pumping rate of the lithium by channeling the plasma to LLD, where strike point location is the most important shape parameter. Simulations show that the density reduction depends on the proximity of strike point to LLD. Experiments were performed to study the dynamics of the strike point, design a new controller to change the location of the strike point to desired location and stabilize it. The most effective PF coils in changing inner and outer strike points were identified using equilibrium code. The PF coil inputs were changed in a step fashion between various set points and the step response of the strike point position was obtained. From the analysis of the step responses, PID controllers for the strike points were obtained and the controller was tuned experimentally for better performance. The strike controller was extended to include the outer-strike point on the inner plate to accommodate the desired low outer-strike points for the experiment with the aim of achieving "snowflake" divertor configuration in NSTX.

Kolemen, E.; Gates, D. A.; Rowley, C. W.; Kasdin, N. J.; Kallman, J.; Gerhardt, S.; Soukhanovskii, V.; Mueller, D.

2010-07-09T23:59:59.000Z

99

Response of NSTX Liquid Lithium divertor to High Heat Loads  

SciTech Connect (OSTI)

Samples of the NSTX Liquid Lithium Divertor (LLD) with and without an evaporative Li coating were directly exposed to a neutral beam ex-situ at a power of ~1.5 MW/m2 for 1-3 seconds. Measurements of front face and bulk sample temperature were obtained. Predictions of temperature evolution were derived from a 1D heat flux model. No macroscopic damage occurred when the "bare" sample was exposed to the beam but microscopic changes to the surface were observed. The Li-coated sample developed a lithium hydroxide (LiOH) coating, which did not change even when the front face temperature exceeded the pure Li melting point. These results are consistent with the lack of damage to the LLD surface and imply that heating alone may not expose pure liquid Li if the melting point of surface impurities is not exceeded. This suggests that flow and heat are needed for future PFCs requiring a liquid Li surface. __________________________________________________

Abrams, Tyler; Kallman, J; Kaitaa, R; Foley, E L; Grayd, T K; Kugel, H; Levinton, F; McLean, A G

2012-07-18T23:59:59.000Z

100

Influence of plasma surface interactions on tokamak startup  

SciTech Connect (OSTI)

The startup phase of a tokamak is a complex phenomenon involving burnthrough of the low-Z impurities and rampup of I{sub p}, the plasma current. The design considerations of a tokamak are closely connected with the startup modeling. Plasma evolution is analysed using a zero-dimensional model. The particle and energy balance is considered of two subclasses of plasmas which are penetrable by neutral gas, together with another component, neutrals trapped in the wall. The first subclass includes plasmas being penetrated by slow neutrals of (?few eV) temperature. The second includes plasmas being penetrated only by fast neutrals having a temperature comparable to that of the ions. The impact of impurities on energy balance is considered through their generation by ion induced desorption of adsorbed oxygen on the first wall and physical and chemical sputtering of carbon. The paper demonstrates self-consistently that the evolution of initial phase of the discharge is intimately linked to the condition of the plasma facing components (PFCs) and the resultant plasma surface interactions.

Goswami, Rajiv [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)] [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2013-08-15T23:59:59.000Z

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101

TEWI Analysis: Its Utility, Its Shortcomings, and Its Results  

SciTech Connect (OSTI)

The past decade has been a challenging time for the refrigeration and air conditioning industry worldwide. Provisions of the Montreal Protocol and its amendments require the phaseout of chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) compounds that have been used extensively as insulating foam blowing agents and refrigerants in refrigeration systems, heat pumps, and air conditioners. In response, hydrofluorocarbon (HFC) compounds were proposed, developed, and are starting to be used as the primary alternatives to CFCs and HCFCs. However, in 1997 under the Kyoto Protocol, industrialized nations have agreed to roll back emissions of HCFCs, carbon dioxide (CO*), and four other greenhouse gases which threaten to cause excessive global warming. The US. Department of Energy and the Alternative Fluorocarbon Environmental Acceptability Study (AFEAS) jointly sponsored research projects to identify the major applications of CFCs, HCFCs, and HFCs and to examine the impacts of these compounds and the energy use of applications employing these compounds on global warming. The five major uses of fluorocarbons based on sales were automobile air conditioning, supermarket refrigeration, unitary heat pumps and air conditioning, chillers for cooling large office buildings, and household refrigeration. Almost all of the refrigerants used in these applications are global warming gases, and if the refrigerant leaks out of the system during operation, is lost during maintenance or is not recovered when the system is scraped, it contributes to global warming. But, it is also true that the energy consumed by refrigeration and air conditioning systems, in the form of electricity or the direct combustion of fossil fuel, results in the release of CO*, the primary cause of atmospheric global warming.

Baxter, V.D.; Fischer, S.K.; Sand, J.R.

1999-09-13T23:59:59.000Z

102

Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies  

SciTech Connect (OSTI)

International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.

Fischer, S.; Sand, J.; Baxter, V.

1997-12-01T23:59:59.000Z

103

The Climate Change Action Plan: Technical supplement  

SciTech Connect (OSTI)

This Technical Annex documents the assumptions and parameters used in developing the supporting analysis for the Climate Change Action Plan (the Plan) issued by President Clinton on October 19, 1993. The Annex is intended to meet the needs of independent energy and environmental analysts who wish to better understand the Plan, its analytical underpinnings, and the events that need to transpire for the emissions reductions called for in the Plan to be realized. The Plan documented in this Annex reflects the outcome of a wide-ranging effort by Government agencies and interested members of the public to develop and implement actions that can reduce net greenhouse gas emissions in the year 2000 to their aggregate 1990 level. Based on agency and public input, the Climate Change Mitigation Group, chaired by the White House Office on Environmental Policy, developed the Plan`s content. Many of the actions called for in the Plan are now underway, while others are in advanced planning pending congressional action on the fiscal year 1995 budget. The analysis supporting the Plan represents the results of an interagency effort. The US Department of Energy (DOE) was responsible for the integrated analysis of energy-related options, based on the analysis of individual energy-related options by DOE, the US Environmental Protection Agency (EPA), and the US Department of Transportation (DOT). EPA led in providing analysis for actions related to methane, hydrofluorocarbons, and perfluorocarbons. The US Department of Agriculture (USDA) led the analysis of carbon sequestration actions and cooperated with EPA in the analysis of actions to reduce nitrous oxide emissions.

Not Available

1994-03-01T23:59:59.000Z

104

Innovative techniques for the description of reservoir heterogeneity using tracers. Second technical annual progress report, October 1991--September 1992  

SciTech Connect (OSTI)

This second annual report on innovative uses of tracers for reservoir characterization contains four sections each describing a novel use of oilfield tracers. The first section describes and illustrates the use of a new single-well tracer test to estimate wettability. This test consists of the injection of brine containing tracers followed by oil containing tracers, a shut-in period to allow some of the tracers to react, and then production of the tracers. The inclusion of the oil injection slug with tracers is unique to this test, and this is what makes the test work. We adapted our chemical simulator, UTCHEM, to enable us to study this tracer method and made an extensive simulation study to evaluate the effects of wettability based upon characteristic curves for relative permeability and capillary pressure for differing wetting states typical of oil reservoirs. The second section of this report describes a new method for analyzing interwell tracer data based upon a type-curve approach. Theoretical frequency response functions were used to build type curves of ``transfer function`` and ``phase spectrum`` that have dimensionless heterogeneity index as a parameter to characterize a stochastic permeability field. We illustrate this method by analyzing field tracer data. The third section of this report describes a new theory for interpreting interwell tracer data in terms of channeling and dispersive behavior for reservoirs. Once again, a stochastic approach to reservoir description is taken. The fourth section of this report describes our simulation of perfluorocarbon gas tracers. This new tracer technology developed at Brookhaven National Laboratory is being tested at the Elk Hills Naval Petroleum Reserve No. 1 in California. We report preliminary simulations made of these tracers in one of the oil reservoirs under evaluation with these tracers in this field. Our compostional simulator (UTCOMP) was used for this simulation study.

Pope, G.A.; Sepehrnoori, K.

1992-12-31T23:59:59.000Z

105

Side-by-side evaluation of a stressed-skin insulated-core panel house and a conventional stud-frame house. Final report  

SciTech Connect (OSTI)

Side-by-side energy testing and monitoring was conducted on two houses in Louisville, KY between January--March 1993. Both houses were identical except that one house was constructed with conventional US 2 by 4 studs and a truss roof while the other house was constructed with stress-skin insulated core panels for the walls and second floor ceiling. Air-tightness testing included fan pressurization by blower door, hour long tracer tests using sulphur hexafluoride, and two-week long time-averaged tests using perfluorocarbon tracers. An average of all the air-tightness test results showed the SSIC panel house to have 22 percent less air infiltration than the frame house. Air-tightness testing resulted in a recommendation that both houses have a fresh air ventilation system installed to provide 0.35 air changes per hour continuously. Thermal insulation quality testing was by infrared imaging. Pressure differential testing resulted in recommendations to use sealed combustion appliances, and to allow for more return air flow from closed rooms. This can be accomplished by separate return ducts or transfer ducts which simply connect closed rooms to the main body with a short duct. The SSIC house UA was lower in both cases. By measurement, co-heating tests showed the SSIC panel house total UA to be 12 percent lower than the frame house. Short-term energy monitoring was also conducted for the two houses. A 17 day period of electric heating and a 14 day period of gas furnace heating was evaluated. Monitoring results showed energy savings for the panel house to be 12 percent during electric heating and 15 percent during gas heating. A comparison of the two monitoring periods showed that the lumped efficiency of the gas furnace and air distribution system for both houses was close to 80 percent. Simple regression models using Typical Meteorological Year weather data gave a preliminary prediction of seasonal energy savings between 14 and 20 percent.

Rudd, A.; Chandra, S.

1994-01-14T23:59:59.000Z

106

Desalination utilizing clathrate hydrates (LDRD final report).  

SciTech Connect (OSTI)

Advances are reported in several aspects of clathrate hydrate desalination fundamentals necessary to develop an economical means to produce municipal quantities of potable water from seawater or brackish feedstock. These aspects include the following, (1) advances in defining the most promising systems design based on new types of hydrate guest molecules, (2) selection of optimal multi-phase reactors and separation arrangements, and, (3) applicability of an inert heat exchange fluid to moderate hydrate growth, control the morphology of the solid hydrate material formed, and facilitate separation of hydrate solids from concentrated brine. The rate of R141b hydrate formation was determined and found to depend only on the degree of supercooling. The rate of R141b hydrate formation in the presence of a heat exchange fluid depended on the degree of supercooling according to the same rate equation as pure R141b with secondary dependence on salinity. Experiments demonstrated that a perfluorocarbon heat exchange fluid assisted separation of R141b hydrates from brine. Preliminary experiments using the guest species, difluoromethane, showed that hydrate formation rates were substantial at temperatures up to at least 12 C and demonstrated partial separation of water from brine. We present a detailed molecular picture of the structure and dynamics of R141b guest molecules within water cages, obtained from ab initio calculations, molecular dynamics simulations, and Raman spectroscopy. Density functional theory calculations were used to provide an energetic and molecular orbital description of R141b stability in both large and small cages in a structure II hydrate. Additionally, the hydrate of an isomer, 1,2-dichloro-1-fluoroethane, does not form at ambient conditions because of extensive overlap of electron density between guest and host. Classical molecular dynamics simulations and laboratory trials support the results for the isomer hydrate. Molecular dynamics simulations show that R141b hydrate is stable at temperatures up to 265K, while the isomer hydrate is only stable up to 150K. Despite hydrogen bonding between guest and host, R141b molecules rotated freely within the water cage. The Raman spectrum of R141b in both the pure and hydrate phases was also compared with vibrational analysis from both computational methods. In particular, the frequency of the C-Cl stretch mode (585 cm{sup -1}) undergoes a shift to higher frequency in the hydrate phase. Raman spectra also indicate that this peak undergoes splitting and intensity variation as the temperature is decreased from 4 C to -4 C.

Simmons, Blake Alexander; Bradshaw, Robert W.; Dedrick, Daniel E.; Cygan, Randall Timothy (Sandia National Laboratories, Albuquerque, NM); Greathouse, Jeffery A. (Sandia National Laboratories, Albuquerque, NM); Majzoub, Eric H. (University of Missouri, Columbia, MO)

2008-01-01T23:59:59.000Z

107

Modeling of CBM production, CO{sub 2} injection, and tracer movement at a field CO{sub 2} sequestration site  

SciTech Connect (OSTI)

Sequestration of carbon dioxide in unmineable coal seams is a potential technology mainly because of the potential for simultaneous enhanced coalbed methane production (ECBM). Several pilot tests have been performed around the globe leading to mixed results. Numerous modeling efforts have been carried out successfully to model methane production and carbon dioxide (CO{sub 2}) injection. Sensitivity analyses and history matching along with several optimization tools were used to estimate reservoir properties and to investigate reservoir performance. Geological and geophysical techniques have also been used to characterize field sequestration sites and to inspect reservoir heterogeneity. The fate and movement of injected CO{sub 2} can be determined by using several monitoring techniques. Monitoring of perfluorocarbon (PFC) tracers is one of these monitoring technologies. As a part of this monitoring technique, a small fraction of a traceable fluid is added to the injection wellhead along with the CO{sub 2} stream at different times to monitor the timing and location of the breakthrough in nearby monitoring wells or offset production wells. A reservoir modeling study was performed to simulate a pilot sequestration site located in the San Juan coal basin of northern New Mexico. Several unknown reservoir properties at the field site were estimated by modeling the coal seam as a dual porosity formation and by history matching the methane production and CO{sub 2} injection. In addition to reservoir modeling of methane production and CO{sub 2} injection, tracer injection was modeled. Tracers serve as a surrogate for determining potential leakage of CO{sub 2}. The tracer was modeled as a non-reactive gas and was injected into the reservoir as a mixture along with CO{sub 2}. Geologic and geometric details of the field site, numerical modeling details of methane production, CO{sub 2} injection, and tracer injection are presented in this paper. Moreover, the numerical predictions of the tracer arrival times were compared with the measured field data. Results show that tracer modeling is useful in investigating movement of injected CO{sub 2} into the coal seam at the field site. Also, such new modeling techniques can be utilized to determine potential leakage pathways, and to investigate reservoir anisotropy and heterogeneity.

Siriwardane, Hema J.; Bowes, Benjamin D.; Bromhal, Grant S.; Gondle, Raj K.; Wells, Arthur W.; Strazisar, Brian R.

2012-07-01T23:59:59.000Z

108

Reduction of Carbon Footprint and Energy Efficiency Improvement in Aluminum Production by Use of Novel Wireless Instrumentation Integrated with Mathematical Modeling  

SciTech Connect (OSTI)

The work addressed the greenhouse gas emission and electrical energy consumption of the aluminum industry. The objective was to provide a means for reducing both through the application of wireless instrumentation, coupled to mathematical modeling. Worldwide the aluminum industry consumes more electrical energy than all activities in many major countries (e.g. the UK) and emits more greenhouse gasses (e.g. than France). Most of these excesses are in the 'primary production' of aluminum; that is the conversion of aluminum oxide to metal in large electrolytic cells operating at hundreds of thousands of amps. An industry-specific GHG emission has been the focus of the work. The electrolytic cells periodically, but at irregular intervals, experience an upset condition known as an 'anode effect'. During such anode effects the cells emit fluorinated hydrocarbons (PFCs, which have a high global warming potential) at a rate far greater than in normal operation. Therefore curbing anode effects will reduce GHG emissions. Prior work had indicated that the distribution of electrical current within the cell experiences significant shifts in the minutes before an anode effect. The thrust of the present work was to develop technology that could detect and report this early warning of an anode effect so that the control computer could minimize GHG emissions. A system was developed to achieve this goal and, in collaboration with Alcoa, was tested on two cells at an Alcoa plant in Malaga, Washington. The project has also pointed to the possibility of additional improvements that could result from the work. Notable among these is an improvement in efficiency that could result in an increase in cell output at little extra operating cost. Prospects for commercialization have emerged in the form of purchase orders for further installations. The work has demonstrated that a system for monitoring the current of individual anodes in an aluminum cell is practical. Furthermore the system has been installed twice on a smelter in the US without exposing workers to hazards usually associated with running signal wires in aluminum plants. The results display the early warning of an anode effect that potentially can be used to minimize such anode effects with their excessive GHG emissions. They also point to a possible, but substantial, economic benefit that could result in improved current efficiency by anode adjustment based on individual anode current measurements.

James W. Evans

2012-04-11T23:59:59.000Z

109

Recent Progress in the NSTX/NSTX-U Lithium Program and Prospects for Reactor-Relevant Liquid-Lithium Based Divertor Development  

SciTech Connect (OSTI)

Developing a reactor compatible divertor has been identified as a particularly challenging technology problem for magnetic confinement fusion. While tungsten has been identified as the most attractive solid divertor material, the NSTX/NSTX-U lithium (Li) program is investigating the viability of liquid lithium (LL) as a potential reactor compatible divertor plasma facing component (PFC) . In the near term, operation in NSTX-U is projected to provide reactor-like divertor heat loads < 40 MW/m^2 for 5 s. During the most recent NSTX campaign, ~ 0.85 kg of Li was evaporated onto the NSTX PFCs where a ~50% reduction in heat load on the Liquid Lithium Divertor (LLD) was observed, attributable to enhanced divertor bolometric radiation. This reduced divertor heat flux through radiation observed in the NSTX LLD experiment is consistent with the results from other lithium experiments and calculations. These results motivate an LL-based closed radiative divertor concept proposed here for NSTX-U and fusion reactors. With an LL coating, the Li is evaporated from the divertor strike point surface due to the intense heat. The evaporated Li is readily ionized by the plasma due to its low ionization energies, and the ionized Li ions can radiate strongly, resulting in a significant reduction in the divertor heat flux. Due to the rapid plasma transport in divertor plasma, the radiation values can be significantly enhanced up to ~ 11 MJ/cc of LL. This radiative process has the desired function of spreading the focused divertor heat load to the entire divertor chamber facilitating the divertor heat removal. The LL divertor surface can also provide a "sacrificial" surface to protect the substrate solid material from transient high heat flux such as the ones caused by the ELMs. The closed radiative LLD concept has the advantages of providing some degree of partition in terms of plasma disruption forces on the LL, Li particle divertor retention, and strong divertor pumping action from the Li-coated divertor chamber wall. By operating at a lower temperature than the first wall, the LLD can serve to purify the entire reactor chamber, as impurities generally migrate toward lower temperature Li-condensed surfaces. To maintain the LL purity, a closed LL loop system with a modest capacity (e.g., ~ 1 Liter/sec for ~ 1% level "impurities") is envisioned for a steady-state 1 GW-electric class fusion power plant.

M. Ono, et al.

2012-10-27T23:59:59.000Z

110

PROOF OF CONCEPT TEST OF A UNIQUE GASEOUS PERFLUROCARBON TRACER SYSTEM FOR VERIFICATION AND LONG TERM MONITORING OF CAPS AND COVER SYSTEMS CONDUCTED AT THE SAVANNAH RIVER SITE BENTONITE MAT TEST FACILITY.  

SciTech Connect (OSTI)

Engineered covers have been placed on top of buried/subsurface wastes to minimize water infiltration and therefore, release of hazardous contaminants. In order for the cover to protect the environment it must remain free of holes and breaches throughout its service life. Covers are subject to subsidence, erosion, animal intrusion, plant root infiltration, etc., all of which will affect the overall performance of the cover. The U.S. Department of Energy Environmental Management (DOE-EM) Program 2006 Accelerated Cleanup Plan is pushing for rapid closure of many of the DOE facilities. This will require a great number of new cover systems. Some of these new covers are expected to maintain their performance for periods of up to 1000 years. Long-term stewardship will require monitoring/verification of cover performance over the course of the designed lifetime. In addition, many existing covers are approaching the end of their design life and will need validation of current performance (if continued use is desired) or replacement (if degraded). The need for a reliable method of verification and long-term monitoring is readily apparent. Currently, failure is detected through monitoring wells downstream of the waste site. This is too late as the contaminants have already left the disposal area. The proposed approach is the use of gaseous Perfluorocarbon tracers (PFT) to verify and monitor cover performance. It is believed that PFTs will provide a technology that can verify a cover meets all performance objectives upon installation, be capable of predicting changes in cover performance and failure (defined as contaminants leaving the site) before it happens, and be cost-effective in supporting stewardship needs. The PFTs are injected beneath the cover and air samples taken above (either air samples or soil gas samples) at the top of the cover. The location, concentrations, and time of arrival of the tracer(s) provide a direct measure of cover performance. PFT technology can be used as a non-invasive method (if injection ports are emplaced prior to cover emplacement) on new covers or a minimally invasive method on existing covers. PFT verification will be useful at all buried waste sites using a cover system (e.g., treated or untreated chemical waste landfills) including DOE, commercial, and private sector sites. This paper discusses the initial field trial of the PFT cover monitoring system performed at the Savannah River Site (SRS) in FY01. The experiments provided a successful proof-of-principle test of the PFT technology in monitoring caps and covers. An injection and sampling array was installed in the Bentomat test cap at the SRS Caps Test Facility. This system contained 6 feet of sandy soil beneath a 1/2 inch geosynthetic clay liner covered by an HDPE liner which was covered by 2 feet of clayey top soil. PFTs were injected into the sandy soil though a pre-existing system of access pipes below the cap and soil gas samples were taken on top of the cap. Mid-way into the injection period a series of 1 1/2 inch holes were punched into the cap (through the geomembrane) to provide a positive breach in the cap. Data will be presented that shows the initial cap was fairly tight and leak free and that the artificially induced leaks were detectable within two hours of occurrence.

HEISER,J.; SULLIVAN,T.; SERRATO,M.

2002-02-24T23:59:59.000Z