Sample records for gas tungsten arc

  1. Gas tungsten arc welder with electrode grinder

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA); Brown, William F. (West Richland, WA)

    1984-01-01T23:59:59.000Z

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  2. Heat transfer in gas tungsten arc welding

    SciTech Connect (OSTI)

    Smartt, H.B.; Stewart, J.A.; Einerson, C.J.

    1986-05-01T23:59:59.000Z

    The heat transferred from an electrode negative, argon gas tungsten arc to an anode has been measured for a wide range of conditions suitable for mechanized welding applications. The results are given as (1) the arc efficiency; and (2) the anode heat and current input distribution functional shapes and radii for various anode materials and groove shapes over a wide range of current and voltage, using different electrode geometries, as well as both He and Ar-He shielding gases. The nominal arc is Gaussian with a diameter of about 4 mm and a heat transfer efficiency to the anode of about 75%. Variations from these values are discussed in terms of current knowledge of the electrical and thermal energy transport mechanisms. A new method of measuring the heat transferred from the arc to the anode, using a boiling liquid nitrogen calorimeter, has been developed which gives rapid, accurate values.

  3. A Glove Box Enclosed Gas-Tungsten Arc Welding System

    SciTech Connect (OSTI)

    Reevr, E, M; Robino, C.V.

    1999-07-01T23:59:59.000Z

    This report describes an inert atmosphere enclosed gas-tungsten arc welding system which has been assembled in support of the MC2730, MC2730A and MC 3500 Radioisotope Thermoelectric Generator (RTG) Enhanced Surveillance Program. One goal of this program is to fabricate welds with microstructures and impurity levels which are similar to production heat source welds previously produced at Los Alamos National Laboratory and the Mound Facility. These welds will subsequently be used for high temperature creep testing as part of the overall component lifetime assessment. In order to maximize the utility of the welding system, means for local control of the arc atmosphere have been incorporated and a wide range of welding environments can easily be evaluated. The gas-tungsten arc welding system used in the assembly is computer controlled, includes two-axis and rotary motion, and can be operated in either continuous or pulsed modes. The system can therefore be used for detailed research studies of welding impurity effects, development of prototype weld schedules, or to mimic a significant range of production-like welding conditions. Fixturing for fabrication of high temperature creep test samples have been designed and constructed, and weld schedules for grip-tab and test welds have been developed. The microstructure of these welds have been evaluated and are consistent with those used during RTG production.

  4. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, Lowell D. (Kingston, TN)

    1984-01-01T23:59:59.000Z

    A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  5. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, L.D.

    1982-03-25T23:59:59.000Z

    The present invention is directed to a gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to profice a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surface are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy continguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  6. Gas-tungsten arc welding of aluminum alloys

    SciTech Connect (OSTI)

    Frye, L.D.

    1984-11-20T23:59:59.000Z

    A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one micro-inch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  7. Heat and mass transfer in the gas tungsten and gas metal arc welding processes

    SciTech Connect (OSTI)

    Watkins, A.D; Smartt, H.B.; Einerson, C.J.; Watkins, J.A.

    1990-01-01T23:59:59.000Z

    The heat transferred from an electrode negative, argon gas tungsten arc to an anode was measured for a wide range of conditions suitable for mechanized welding. The results are given as (1) the arc efficiency and (2) the anode heat and current input distributions for various anode materials over a range of current and voltage. The nominal arc is Gaussian, {approximately}4 mm in diameter, with {approximately}75{percent}heat transfer efficiency. Variations from these values are discussed in terms of the electrical and thermal energy transport mechanisms. Heat transferred to the workpiece (cathode) during direct current, electrode positive gas metal arc welding (GMAW) was measured for various parameters applicable to machine welding. The results are presented as a function of electrode speed for changing voltages and contact tip to workpiece distances. The total heat transfer efficiency was nominally 85{percent} for a 0.89 mm diameter steel electrode using an argon-2{percent} oxygen shielding gas; the nominal heat transfer efficiency of the droplet component was 40{percent}. The average droplet temperatures ranged from 2400 to 3100 K, depending on the process parameters. A new method of measuring the heat transferred from the arc to the workpiece, using a boiling liquid nitrogen calorimeter, has been developed that gives rapid, accurate values. 20 refs., 8 figs., 2 tabs.

  8. Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

    DOE Patents [OSTI]

    Heiple, C.R.; Burgardt, P.

    1984-03-13T23:59:59.000Z

    An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

  9. Parametric Studies Of Weld Quality Of Tungsten Inert Gas Arc Welding Of Stainless Steel

    SciTech Connect (OSTI)

    Kumar Pal, Pradip; Nandi, Goutam; Ghosh, Nabendu [Mechanical Engineering Department, Jadavpur University, Kolkata-700032 (India)

    2011-01-17T23:59:59.000Z

    Effect of current and gas flow rate on quality of weld in tungsten inter gas arc welding of austenitic stainless steel has been studied in the present work through experiments and analyses. Butt welded joints have been made by using several levels of current and gas flow rate. The quality of the weld has been evaluated in terms of ultimate and breaking strengths of the welded specimens. The observed data have been interpreted, discussed and analyzed by using Grey--Taguchi methodology. Optimum parametric setting has been predicted and validated as well.

  10. A calorimetric-based comparison of gas tungsten and plasma arc welding processes

    SciTech Connect (OSTI)

    Knorovsky, G.A.; Fuerschbach, P.W.

    1988-01-01T23:59:59.000Z

    Measurements of arc and melting efficiencies have been made for pulsed and continuous mode Gas Tungsten Arc Welding (GTAW) and Plasma Arc Welding (PAW) processes. Welds were made on 2.5 mm total thickness pure Ni and 304 Stainless Steel in a standing edge weld geometry at constant nominal machine output settings which varied average current with travel speed. Under continuous current conditions, the measured heat input remained approximately constant for the conditions examined (250-1250 mm/min), while melting efficiency increased dramatically (0-/approximately/0.4). Arc efficiencies were relatively constant, remaining in the range of /approximately/0.75-0.85 for GTAW and somewhat less for PAW. Values of melting efficiency for Ni were slightly less than those for 304 when compared at similar travel speeds, though both tended toward the same limit (/approximately/0.4). The PAW results were not appreciably higher than the GTAW. In addition to melting efficiency the centerline depth of penetration was also measured. In contrast to the GTAW results, which increased with speed at lower travel speeds and then plateaued at 0.8 mm, the PAW results increased monotonically with speed to a maximum of 1.0 mm. In conclusion, calorimetric measurements of nonconsumable arc welding processes have been found helpful in understanding conditions under which efficient arc welds with minimal heat inputs for a desired weld penetration can be made. 10 figs.

  11. Remote reactor repair: GTA (gas tungsten Arc) weld cracking caused by entrapped helium

    SciTech Connect (OSTI)

    Kanne, W.R. Jr.

    1988-01-01T23:59:59.000Z

    A repair patch was welded to the wall of a nuclear reactor tank using remotely controlled thirty-foot long robot arms. Further repair was halted when gas tungsten arc (GTA) welds joining type 304L stainless steel patches to the 304 stainless steel wall developed toe cracks in the heat-affected zone (HAZ). The role of helium in cracking was investigated using material with entrapped helium from tritium decay. As a result of this investigation, and of an extensive array of diagnostic tests performed on reactor tank wall material, helium embrittlement was shown to be the cause of the toe cracks.

  12. Progress report on a fully automatic Gas Tungsten Arc Welding (GTAW) system development

    SciTech Connect (OSTI)

    Daumeyer, G.J. III

    1994-12-01T23:59:59.000Z

    A plan to develop a fully automatic gas tungsten arc welding (GTAW) system that will utilize a vision-sensing computer (which will provide in-process feedback control) is presently in work. Evaluations of different technological aspects and system design requirements continue. This report summaries major activities in the plan`s successful progress. The technological feasibility of producing the fully automated GTAW system has been proven. The goal of this process development project is to provide a production-ready system within the shortest reasonable time frame.

  13. Causal Factors of Weld Porosity in Gas Tungsten Arc Welding of Powder Metallurgy Produced Titanium Alloys

    SciTech Connect (OSTI)

    Muth, Thomas R [ORNL; Yamamoto, Yukinori [ORNL; Frederick, David Alan [ORNL; Contescu, Cristian I [ORNL; Chen, Wei [ORNL; Lim, Yong Chae [ORNL; Peter, William H [ORNL; Feng, Zhili [ORNL

    2013-01-01T23:59:59.000Z

    ORNL undertook an investigation using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate, to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas forming species. PM-titanium made from revert scrap where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders prior to consolidation. The removal / minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders, are critical to achieve equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.

  14. Theoretical analysis of weld pool behavior in the pulsed current Gas Tungsten Arc Welding (GTAW) process

    SciTech Connect (OSTI)

    Tsai, C.L. (Ohio State Univ., Columbus (United States)); Hou, C.A. (Howard Univ., Washington, DC (United States))

    1988-02-01T23:59:59.000Z

    A general three-dimensional, closed-form welding heat-flow solution, which is capable of analyzing thermal behavior of the weldment in its transient state and/or under time-dependent power change during welding, is presented. The analytical model utilizes the finite heat source theory with a Gaussian distribution and also considers the effects of finite plate thickness. The numerical values of the solution are calculated using the computational schemes on a minicomputer. In this paper the welding parameters of the pulsed current Gas Tungsten Arc Welding (GTAW) were studied using the solution. Two sets of pulsation parameters were analyzed and their sensitivity to the heat input control were evaluated.

  15. Vaccum Gas Tungsten Arc Welding, phase 1. Technical report, October 1993-March 1995

    SciTech Connect (OSTI)

    Weeks, J.L.; Krotz, P.D.; Todd, D.T.; Liaw, Y.K.

    1995-03-01T23:59:59.000Z

    This two year program will investigate Vacuum Gas Tungsten Arc Welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. VGTAW appears to offer a significant improvement in weldability because of the clean environment and lower heat input needed. The overall objective of the program is to develop the VGTAW technology and implement it into a manufacturing environment that will result in lower cost, better quality and higher reliability aerospace components for the space shuttle and other NASA space systems. Phase 1 of this program was aimed at demonstrating the process`s ability to weld normally difficult-to-weld materials. Phase 2 will focus on further evaluation, a hardware demonstration and a plan to implement VGTAW technology into a manufacturing environment. During Phase 1, the following tasks were performed: (1) Task 11000 Facility Modification - an existing vacuum chamber was modified and adapted to a GTAW power supply; (2) Task 12000 Materials Selection - four difficult-to-weld materials typically used in the construction of aerospace hardware were chosen for study; (3) Task 13000 VGTAW Experiments - welding experiments were conducted under vacuum using the hollow tungsten electrode and evaluation. As a result of this effort, two materials, NARloy Z and Incoloy 903, were downselected for further characterization in Phase 2; and (4) Task 13100 Aluminum-Lithium Weld Studies - this task was added to the original work statement to investigate the effects of vacuum welding and weld pool vibration on aluminum-lithium alloys.

  16. Microstructure evolution of Al/Mg butt joints welded by gas tungsten arc with Zn filler metal

    SciTech Connect (OSTI)

    Liu Fei; Zhang Zhaodong; Liu Liming, E-mail: liulm@dlut.edu.cn

    2012-07-15T23:59:59.000Z

    Based on the idea of alloying welding seam, Gas tungsten arc welding method with pure Zn filler metal was chosen to join Mg alloy and Al alloy. The microstructures, phases, element distribution and fracture morphology of welding seams were examined. The results indicate that there was a transitional zone in the width of 80-100 {mu}m between the Mg alloy substrate and fusion zone. The fusion zone was mainly composed of MgZn{sub 2}, Zn-based solid solution and Al-based solid solution. The welding seam presented distinct morphology in different location owning to the quite high cooling rate of the molten pool. The addition of Zn metal could prevent the formation of Mg-Al intermetallics and form the alloyed welding seam during welding. Therefore, the tensile strengths of joints have been significantly improved compared with those of gas tungsten arc welded joints without Zn metal added. Highlights: Black-Right-Pointing-Pointer Mg alloy AZ31B and Al alloy 6061 are welded successfully. Black-Right-Pointing-Pointer Zinc wire is employed as a filler metal to form the alloyed welding seam. Black-Right-Pointing-Pointer An alloyed welding seam is benefit for improving of the joint tensile strength.

  17. Abnormal macropore formation during double-sided gas tungsten arc welding of magnesium AZ91D alloy

    SciTech Connect (OSTI)

    Shen Jun [College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China)], E-mail: shenjun2626@163.com; You Guoqiang; Long Siyuan [College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China); Pan Fusheng [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2008-08-15T23:59:59.000Z

    One of the major concerns during gas tungsten arc (GTA) welding of cast magnesium alloys is the presence of large macroporosity in weldments, normally thought to occur from the presence of gas in the castings. In this study, a double-sided GTA welding process was adopted to join wrought magnesium AZ91D alloy plates. Micropores were formed in the weld zone of the first side that was welded, due to precipitation of H{sub 2} as the mushy zone freezes. When the reverse side was welded, the heat generated caused the mushy zone in the initial weld to reform. The micropores in the initial weld then coalesced and expanded to form macropores by means of gas expansion through small holes that are present at the grain boundaries in the partially melted zone. Macropores in the partially melted zone increase with increased heat input, so that when a filler metal is used the macropores are smaller in number and in size.

  18. Narrow groove gas tungsten arc welding of ASTM A508 Class 4 steel for improved toughness properties

    SciTech Connect (OSTI)

    Penik, M.A. Jr. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1997-04-01T23:59:59.000Z

    Welding of heavy section steel has traditionally used the automatic submerged arc welding (ASAW) process because of the high deposition rates achievable. However, the properties, particularly fracture toughness, of the weld are often inferior when compared to base material. This project evaluated the use of narrow groove gas tungsten arc welding (GTAW) to improve weld material properties. The welding procedures were developed for ASTM A508 Class 4 base material using a 1% Ni filler material complying to AWS Specification A.23-90-EF3-F3-N. A narrow groove joint preparation was used in conjunction with the GTAW process so competitive fabrication rates could be achieved when compared to the ASAW process. Weld procedures were developed to refine weld substructure to achieve better mechanical properties. Two heaters of weld wire were used to examine the effects of minor filler metal chemistry differences on weld mechanical properties. Extensive metallographic evaluations showed excellent weld quality with a refined microstructure. Chemical analysis of the weld metal showed minimal weld dilution by the base metal. Mechanical testing included bend and tensile tests to ensure weld quality and strength. A Charpy impact energy curve versus temperature and fracture toughness curve versus temperature were developed for each weld wire heat. Results of fracture toughness and Charpy impact testing indicated an improved transition temperature closer to that of the base material properties.

  19. Computational modeling of GTA (gas tungsten arc) welding with emphasis on surface tension effects

    SciTech Connect (OSTI)

    Zacharia, T.; David, S.A.

    1990-01-01T23:59:59.000Z

    A computational study of the convective heat transfer in the weld pool during gas tungsten arch (GTA) welding of Type 304 stainless steel is presented. The solution of the transport equations is based on a control volume approach which utilized directly, the integral form of the governing equations. The computational model considers buoyancy and electromagnetic and surface tension forces in the solution of convective heat transfer in the weld pool. In addition, the model treats the weld pool surface as a deformable free surface. The computational model includes weld metal vaporization and temperature dependent thermophysical properties. The results indicate that consideration of weld pool vaporization effects and temperature dependent thermophysical properties significantly influence the weld model predictions. Theoretical predictions of the weld pool surface temperature distributions and the cross-sectional weld pool size and shape wee compared with corresponding experimental measurements. Comparison of the theoretically predicted and the experimentally obtained surface temperature profiles indicated agreement with {plus minus} 8%. The predicted weld cross-section profiles were found to agree very well with actual weld cross-sections for the best theoretical models. 26 refs., 8 figs.

  20. Analysis of effect of temperature gradients on surface-tension phenomena in gas-tungsten-arc welds

    SciTech Connect (OSTI)

    Lee, H.A.; Chien, P.S.J.

    1982-10-01T23:59:59.000Z

    Fluid motion directed by surface tension is considered as a contributor to heat penetration in a weld pool. The potential phenomena at the gas-liquid interface were analyzed, and the dependence of surface motion on temperature in the gas-tungsten-arc (GTA) welding process was examined. An existing heat-transfer model was used and was able to predict weld size to +- 50% of the actual value. A momentum-transfer equation was derived by considering the contribution of Lorentz force. The momentum boundary condition was developed and was able to predict the Marangoni effect. The magnitude of surface-tension-driven force is comparable to the gravitational force on one gram. An empirical approach was proposed to couple heat-transfer and momentum-transfer phenomena. A dimensional analysis identified the pertinent dimensionless groups as Reynolds, Weber, Froude, Peclet, and Power numbers and a dimensionless velocity. A simplified form of the correction was developed by combining dimensionless groups to yield a correlation with the Bond, Prandtl, and modified power numbers. Future experimental work was proposed to test the functionality of the dimensionless groups.

  1. Mechanical properties and microstructures of a magnesium alloy gas tungsten arc welded with a cadmium chloride flux

    SciTech Connect (OSTI)

    Zhang, Z.D. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, L.M. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)], E-mail: liulm@dlut.edu.cn; Shen, Y.; Wang, L. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2008-01-15T23:59:59.000Z

    Gas tungsten arc (GTA) welds were prepared on 5-mm thick plates of wrought magnesium AZ31B alloy, using an activated flux. The microstructural characteristics of the weld joint were investigated using optical and scanning microscopy, and the fusion zone microstructure was compared with that of the base metal. The elemental distribution was also investigated by electron probe microanalysis (EPMA). Mechanical properties were determined by standard tensile tests on small-scale specimens. The as-welded fusion zone prepared using a CdCl{sub 2} flux exhibited a larger grain size than that prepared without flux; the microstructure consisted of matrix {alpha}-Mg, eutectic {alpha}-Mg and {beta}-Al{sub 12}Mg{sub 17}. The HAZ was observed to be slightly wider for the weld prepared with a CdCl{sub 2} flux compared to that prepared without flux; thus the tensile strength was lower for the flux-prepared weld. The fact that neither Cd nor Cl was detected in the weld seam by EPMA indicates that the CdCl{sub 2} flux has a small effect on convection in the weld pool.

  2. Abnormal distribution of microhardness in tungsten inert gas arc butt-welded AZ61 magnesium alloy plates

    SciTech Connect (OSTI)

    Xu Nan [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Shen Jun, E-mail: shenjun2626@163.com [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Xie Weidong; Wang Linzhi; Wang Dan; Min Dong [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2010-07-15T23:59:59.000Z

    In this study, the effects of heat input on the distribution of microhardness of tungsten inert gas (TIG) arc welded hot-extruded AZ61 magnesium alloy joints were investigated. The results show that with an increase of heat input, the distributions of microhardness at the top and bottom of the welded joints are different because they are determined by both the effect of grain coarsening and the effect of dispersion strengthening. With an increase of the heat input, the microhardness of the heat-affected zone (HAZ) at the top and bottom of welded joints and the fusion zone (FZ) at the bottom of welded joints decreased gradually, while the microhardness of the FZ at the top of welded joints decreased initially and then increased sharply. The reason for the abnormal distribution of microhardness of the FZ at the top of the welded joints is that this area is close to the heat source during welding and then large numbers of hard {beta}-Mg{sub 17}(Al,Zn){sub 12} particles are precipitated. Hence, in this case, the effect of dispersion strengthening dominated the microhardness.

  3. GTAW penetration based on electrode tip location versus weld joint center line. [Gas Tungsten Arc Welding (GTAW)

    SciTech Connect (OSTI)

    Daumeyer, G.J. III.

    1992-11-01T23:59:59.000Z

    Gas Tungsten Arc Welding (GTAW) is often the chosen process for final enclosure welds of heat sensitive electrical and electronic product. GTAW is used to produce welds that satisfy design requirements (usually a penetration requirement) and not expose the product to such high heat that would cause unwanted damage. An important variable in the GTAW process is the location of the Electrode tip over the weld joint center line. This study shows the tolerance of positional location over a narrow scope. Using coupons which represent the W88 container weld joint geometry, penetration vs. electrode tip positional location (offset) is investigated. Results indicate a positional location tolerance of [plus minus] 0.008 in. is acceptable. Several different major components (MCS) supporting various weapons programs require low heat input GTA welds. The electrode tip positional location tolerance is determined by each MC's weld joint tolerances and heat sensitivity. For this short study, the weld joint geometry of a container weld was used. These coupons were welded with the specified weld schedule and one additional weld schedule in order to show the relationship based on both travel speed and gap. Multiple coupon welds were made to eliminate error in the results. Within the scope of this research, a positional tolerance of [plus minus] 0.008 in. of the electrode center over the weld joint center is required. For other MCs this tolerance may be tighter or more relaxed depending upon the specific considerations.

  4. Visible Light Emissions during Gas Tungsten Arc Welding and Its Application to Weld

    E-Print Network [OSTI]

    Eagar, Thomas W.

    emission, were also determined. An improved image of the weld pool can be obtained by operating within will require development of new sensor systems. As the "Yelding arc is a harsh environment, noncontacting to control joint tracking and weld E. W. KIM, C. ALLEMAND and T. W. EAGAR are with the Massachusetts

  5. Environmental embrittlement of iron-aluminide alloy FA-129 during gas tungsten arc welding

    SciTech Connect (OSTI)

    Fasching, A.A.; Edwards, G.R. [Colorado School of Mines, Golden, CO (United States); David, S.A. [Oak Ridge National Lab, Oak Ridge, TN (United States)

    1994-12-31T23:59:59.000Z

    Iron aluminides are susceptible to hydrogen cold cracking during gastungsten arc welding (GTAW). Cracking occurs by brittle fracture in the fusion zone, which has been attributed to excessive grain growth during solidification. To further investigate hydrogen cold cracking in iron aluminides and, specifically, to study the effect of base material grain size on fusion zone cracking susceptibility, base materials of varying grain size were GTAW. The specimens for this investigation came from a production-sized vacuum arc remelt (VAR) ingot. The results of this investigation showed that changes in either the base material thermomechanical processing or the common welding parameters could not easily be used to refine the fusion zone grain size. This investigation showed that conventional GTAW produced coarse fusion zone grain structures even in fine-grained base material. The results also revealed that fracture strength decreased only slightly with a decrease in heat input, but exhibited a dramatic decrease as the water vapor content increased. in addition, the unrecrystallized base material showed the greatest susceptibility toward hydrogen cold cracking. Fracture stress versus grain size plots at different levels of water vapor were produced for iron-aluminide alloy FA-129.

  6. On-line weld penetration detection and control in automated gas tungsten arc welding. Ph.D. Thesis

    SciTech Connect (OSTI)

    Banerjee, P.

    1994-01-01T23:59:59.000Z

    The present work was undertaken to study the feasibility of monitoring and controlling weld penetration variations in real-time using an infrared detector. Weld penetration variations induced on mild steel plates were examined with an infrared detector and the acquired data analyzed to detect weld penetration variations using a mathematical analysis. Selected weld penetration indicators were developed and used to demonstrate on-line weld penetration control. A three-dimensional solid-state, transient heat transfer model was also developed to help identify key changes in thermal distributions which could be used as weld penetration indicators. A transient three-dimensional heat transfer model was used to solve the differential energy balance for the GTA welding process. The computed temperatures obtained from the model were used to determine the variation of the isothermal map, surface temperature profile and temperature gradient with weld penetration. Good agreement between experimental and computed indicators was obtained. Gas tungsten arc welds were performed on steel plates with intentionally introduced defects such as sudden thickness changes and minor element content changes. Extensive mathematical analysis helped correlate weld penetration variations to parameters such as the peak infrared intensity, intensity gradient over a fixed distance, intensity gradient at the inflection points in the first differential of the intensity profile (linescan), computed width of the weld pool, intensity gradient at a point in the weld pool, area enclosed by the linescan and area enclosed by the linescan after compensating for background illumination. The shape of the weld pool front was also determined from a differential analysis of the infrared data. Inconsistent behavior of some weld penetration indicators led to their elimination from the selection process for the best error signal.

  7. Effect of heat input on the microstructure and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates

    SciTech Connect (OSTI)

    Min Dong [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Shen Jun, E-mail: shenjun2626@163.com [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Lai Shiqiang; Chen Jie [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2009-12-15T23:59:59.000Z

    In this paper, the effects of heat input on the microstructures and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates were investigated by microstructural observations, microhardness tests and tensile tests. The results show that with an increase of the heat input, the grains both in the fusion zone and the heat-affected zone coarsen and the width of the heat-affected zone increased. Moreover, an increase of the heat input resulted in a decrease of the continuous {beta}-Mg{sub 17}Al{sub 12} phase and an increase of the granular {beta}-Mg{sub 17}Al{sub 12} phase in both the fusion zone and the heat-affected zone. The ultimate tensile strength of the welded joint increased with an increase of the heat input, while, too high a heat input resulted in a decrease of the ultimate tensile strength of the welded joint. In addition, the average microhardness of the heat-affected zone and fusion zone decreased sharply with an increase of the heat input and then decreased slowly at a relatively high heat input.

  8. Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D

    E-Print Network [OSTI]

    Zhou, Wei

    Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D W. Zhou*, T. Z. Long and C. K of the plates were produced using tungsten inert gas (TIG) welding method. The TIG arc was also used to deposit welding beads on some of the thin plates. No cracking was found in the butt joints. However, hot cracking

  9. Effect of hydrogen in an argon GTAW shielding gas: Arc characteristics and bead morphology

    SciTech Connect (OSTI)

    Onsoeien, M.; Olson, D.L.; Liu, S. (Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research); Peters, R. (Delft Technological Univ. (Netherlands))

    1995-01-01T23:59:59.000Z

    The influence of hydrogen additions to an argon shielding gas on the heat input and weld bead morphology was investigated using the gas tungsten arc welding process. Variations in weld bead size and shape with hydrogen additions were related to changes in the ability of the arc to generate heat and not to generate perturbations in the weld pool caused by Marangoni fluid flow.

  10. Welding arc initiator

    DOE Patents [OSTI]

    Correy, T.B.

    1989-05-09T23:59:59.000Z

    An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome. 3 figs.

  11. Welding arc initiator

    DOE Patents [OSTI]

    Correy, Thomas B. (Richland, WA)

    1989-01-01T23:59:59.000Z

    An improved inert gas shielded tungsten arc welder is disclosed of the type wherein a tungsten electrode is shielded within a flowing inert gas, and, an arc, following ignition, burns between the energized tungsten electrode and a workpiece. The improvement comprises in combination with the tungsten electrode, a starting laser focused upon the tungsten electrode which to ignite the electrode heats a spot on the energized electrode sufficient for formation of a thermionic arc. Interference problems associated with high frequency starters are thus overcome.

  12. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 50, NO. 3, JUNE 2001 697 Robust Sensing of Arc Length

    E-Print Network [OSTI]

    Zhang, YuMing

    the distribution of the arc energy and thus the heat input and width of the weld. This work aims at improving research and equipment development. The gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW tungsten arc welding (GTAW) with argon shield. To this end, effects of welding parame- ters on spectral

  13. THE REMOVAL OF CARBON/BEUTERIUM FROM STAINLESS STEEL AND TUNGSTEN BY TRANSFERRED-ARC CLEANING

    SciTech Connect (OSTI)

    K. J. HOLLIS; R. G. CASTRO; ET AL

    2001-04-01T23:59:59.000Z

    Tungsten and stainless steel samples have been contaminated with deuterium and carbon to simulate deposited layers in magnetic-confinement fusion devices. Deuterium and carbon were co-deposited onto the sample surfaces using a deuterium plasma seeded with varying amounts of deuterated methane. Deuterium was also implanted into the samples in an accelerator to simulate hydrogen isotope ion implantation conditions in magnetic confinement fusion devices. Cathodic arc, or transferred-arc (TA) cleaning was employed to remove the deposits from the samples. The samples were characterized by ion beam analysis both before and after cleaning to determine deuterium and carbon concentrations present. The deuterium content was greatly reduced by the cleaning thus demonstrating the possibility of using the TA cleaning technique for removing deuterium and/or tritium from components exposed to D-T fuels. Removal of surface layers and significant reduction of subsurface carbon concentrations was also observed.

  14. Method for controlling gas metal arc welding

    DOE Patents [OSTI]

    Smartt, Herschel B. (Idaho Falls, ID); Einerson, Carolyn J. (Idaho Falls, ID); Watkins, Arthur D. (Idaho Falls, ID)

    1989-01-01T23:59:59.000Z

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections.

  15. Method for controlling gas metal arc welding

    DOE Patents [OSTI]

    Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

    1987-08-10T23:59:59.000Z

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

  16. Gas phase reaction products during tungsten atomic layer deposition using WF6 and Si2H6

    E-Print Network [OSTI]

    George, Steven M.

    Gas phase reaction products during tungsten atomic layer deposition using WF6 and Si2H6 R. K; published 23 July 2004 The gas phase reaction products during tungsten W atomic layer deposition ALD using WF6 and Si2H6 were studied using quadrupole mass spectrometry. The gas phase reactions products were

  17. Modelling of the bead formation during multi pass hybrid laser/gas metal arc welding

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - 1 - Modelling of the bead formation during multi pass hybrid laser/gas metal arc welding Olivier dimensional finite element model has been developed to simulate weld bead formation in multi pass hybrid laser/gas metal arc welding. The model considers both a gas metal arc welding (GMAW) electrode and a laser beam

  18. Heat and Metal Transfer in Gas Metal Arc Welding Using Argon and Helium

    E-Print Network [OSTI]

    Eagar, Thomas W.

    Heat and Metal Transfer in Gas Metal Arc Welding Using Argon and Helium P.G. JONSSON, T.W. EAGAR transfer in gas metal arc welding (GMAW) of mild steel using argon and helium shielding gases. Major dif properties. Various findings from the study include that an arc cannot be stru~k in a pure helium atmosphere

  19. Investigation of arc length versus flange thickness while using an arc voltage controller

    SciTech Connect (OSTI)

    Daumeyer, G.J.

    1994-11-01T23:59:59.000Z

    An arc voltage controller (AVC) for gas tungsten arc welding will change arc length when flange thickness changes while all other variables, including AVC setting, are held constant. A procedure for calibrating an LVDT (linear variable displacement transducer) used for electrode assembly motion monitoring was proven for laboratory setups and special investigations. A partial characterization on the deadband and sensitivity control settings of the Cyclomatic AVC was completed.

  20. DIGITAL SIGNAL PROCESSING AS A DIAGNOSTIC TOOL FOR GAS

    E-Print Network [OSTI]

    Eagar, Thomas W.

    DIGITAL SIGNAL PROCESSING AS A DIAGNOSTIC TOOL FOR GAS TUNGSTEN ARC WELDING Carl D. Sorensen by the intense heat and light of the ·elding arc. To avoid these problems it is desirable to use the welding arc. The arc is treated as an electrical "black box" with the weld current as an input and the weld voltage

  1. Mechanisms of gas precipitation in plasma-exposed tungsten

    SciTech Connect (OSTI)

    R. D. Kolasinski; D. F. Cowgill; D. C. Donovan; M. Shimada

    2012-05-01T23:59:59.000Z

    Precipitation in subsurface bubbles is a key process that governs how hydrogen isotopes migrate through and become trapped within plasma-exposed tungsten. We describe a continuum-scale model of hydrogen diffusion in plasma-exposed materials that includes the effects of precipitation. The model can account for bubble expansion via dislocation loop punching, using an accurate equation of state to determine the internal pressure. This information is used to predict amount of hydrogen trapped by bubbles, as well as the conditions where the bubbles become saturated. In an effort to validate the underlying assumptions, we compare our results with published positron annihilation and thermal desorption spectroscopy data, as well as our own measurements using the tritium plasma experiment (TPE).

  2. Direct Modeling of Material Deposit and Identification of Energy Transfer in Gas Metal Arc Welding

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Direct Modeling of Material Deposit and Identification of Energy Transfer in Gas Metal Arc Welding sources for finite element simulation of gas metal arc welding (GMAW). Design for the modeling of metal deposition results in a direct calculation of the formation of the weld bead, without any

  3. ~DELING OF METAL TRANSFKR IN GAS METAL ARC WELDING Yong -Seog Kim and T. W. Eagar

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) ) ~DELING OF METAL TRANSFKR IN GAS METAL ARC WELDING Yong -Seog Kim and T. W. Eagar theory and the pinch i ns t a bility theor y as a function of welding cur rent . Experimental of the gas metal arc process in the late 1940s, it has become one of the most important welding processes

  4. Three-dimensional modeling of the plasma arc in arc welding

    SciTech Connect (OSTI)

    Xu, G.; Tsai, H. L. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, 1870 Miner Circle, Rolla, Missouri 65409 (United States); Hu, J. [Department of Mechanical Engineering, University of Bridgeport, Bridgeport, Connecticut 06604 (United States)

    2008-11-15T23:59:59.000Z

    Most previous three-dimensional modeling on gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool dynamics and assumes the two-dimensional axisymmetric Gaussian distributions for plasma arc pressure and heat flux. In this article, a three-dimensional plasma arc model is developed, and the distributions of velocity, pressure, temperature, current density, and magnetic field of the plasma arc are calculated by solving the conservation equations of mass, momentum, and energy, as well as part of the Maxwell's equations. This three-dimensional model can be used to study the nonaxisymmetric plasma arc caused by external perturbations such as an external magnetic field. It also provides more accurate boundary conditions when modeling the weld pool dynamics. The present work lays a foundation for true three-dimensional comprehensive modeling of GTAW and GMAW including the plasma arc, weld pool, and/or electrode.

  5. METAL TRANSFER CONTROL IN GAS METAL ARC WELDING L.A. Jones, T.W. Eagar, J.H. Lang

    E-Print Network [OSTI]

    Eagar, Thomas W.

    METAL TRANSFER CONTROL IN GAS METAL ARC WELDING L.A. Jones, T.W. Eagar, J.H. Lang Massachusetts Institute of Technology Cambridge, MA 02139 USA Abstract Power input to the arc in gas metal arc welding to decouple these processes. Methods to achieve this decoupling are discussed. Pulsed-power welding is widely

  6. Exhaust-gas measurements from NASAs HYMETS arc jet.

    SciTech Connect (OSTI)

    Miller, Paul Albert

    2010-11-01T23:59:59.000Z

    Arc-jet wind tunnels produce conditions simulating high-altitude hypersonic flight such as occurs upon entry of space craft into planetary atmospheres. They have traditionally been used to study flight in Earth's atmosphere, which consists mostly of nitrogen and oxygen. NASA is presently using arc jets to study entry into Mars' atmosphere, which consists of carbon dioxide and nitrogen. In both cases, a wide variety of chemical reactions take place among the gas constituents and with test articles placed in the flow. In support of those studies, we made measurements using a residual gas analyzer (RGA) that sampled the exhaust stream of a NASA arc jet. The experiments were conducted at the HYMETS arc jet (Hypersonic Materials Environmental Test System) located at the NASA Langley Research Center, Hampton, VA. This report describes our RGA measurements, which are intended to be used for model validation in combination with similar measurements on other systems.

  7. Thermal-treatment effect on the photoluminescence and gas-sensing properties of tungsten oxide nanowires

    SciTech Connect (OSTI)

    Sun, Shibin [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China); Chang, Xueting [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100, Shandong (China)] [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100, Shandong (China); Li, Zhenjiang, E-mail: zjli126@126.com [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)

    2010-09-15T23:59:59.000Z

    Single-crystalline non-stoichiometric tungsten oxide nanowires were initially prepared using a simple solvothermal method. High resolution transmission electron microscopy (HRTEM) investigations indicate that the tungsten oxide nanowires exhibit various crystal defects, including stacking faults, dislocations, and vacancies. A possible defect-induced mechanism was proposed to account for the temperature-dependent morphological evolution of the tungsten oxide nanowires under thermal processing. Due to the high specific surface areas and non-stoichiometric crystal structure, the original tungsten oxide nanowires were highly sensitive to ppm level ethanol at room temperature. Thermal treatment under dry air condition was found to deteriorate the selectivity of room-temperature tungsten oxide sensors, and 400 {sup o}C may be considered as the top temperature limit in sensor applications for the solvothermally-prepared nanowires. The photoluminescence (PL) characteristics of tungsten oxide nanowires were also strongly influenced by thermal treatment.

  8. Characterization of Gas Metal Arc Welding welds obtained with new high Cr-Mo ferritic stainless steel filler wires

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Characterization of Gas Metal Arc Welding welds obtained with new high Cr-Mo ferritic stainless Several compositions of metal cored filler wire were manufactured to define the best welding conditions for homogeneous welding, by Gas Metal Arc Welding (GMAW) process, of a modified AISI 444 ferritic stainless steel

  9. Computational Modeling of Microstructural-Evolution in AISI 1005 Steel During Gas Metal Arc Butt Welding

    E-Print Network [OSTI]

    Grujicic, Mica

    Welding M. Grujicic, S. Ramaswami, J.S. Snipes, R. Yavari, A. Arakere, C.-F. Yen, and B.A. Cheeseman-mechanical finite-element procedure is developed to model conventional gas metal arc welding (GMAW) butt of the workpiece and the weld temperature- dependent and by allowing the potential work of plastic deformation

  10. Numerical Analysis of Metal Transfer in Gas Metal Arc Welding under Modified Pulsed Current Conditions

    E-Print Network [OSTI]

    Zhang, YuMing

    causes a thermal load too high to apply to thin sectioned or heat-sensitive materials. In an effort was assumed as the boundary condition for the calculation of the electromagnetic force. The calculations were agreement between calculation and experimental results. I. INTRODUCTION IN gas metal arc welding (GMAW

  11. Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor-Grade

    E-Print Network [OSTI]

    Grujicic, Mica

    Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor metal arc welding (GMAW) butt-joining process has been modeled using a two-way fully coupled, transient in the form of heat, and the mechanical material model of the workpiece and the weld is made temperature

  12. The dynamics of droplet formation and detachment in gas metal arc welding

    SciTech Connect (OSTI)

    Johnson, J.A.; Smartt, H.B.; Clark, D.E.; Carlson, N.M.; Watkins, A.D.; Lethcoe, B.J.

    1990-01-01T23:59:59.000Z

    Experimental measurements of gas metal arc welding are required for the development and confirmation of models of the process. This paper reports on two experiments that provide information for models of the arc physics and of the weld pool dynamics. The heat transfer efficiency of the spray transfer mode in gas metal arc welding was measured using a calorimetry technique. The efficiency varied from 75 to 85%. A special fixture was used to measure the droplet contribution, which is determined to be between 35 and 45% of the total input energy. A series of experiments was performed at a variety of conditions ranging from globular to spray to streaming transfer. The transfer was observed by taking high-speed movies at 500 to 5000 frames per second of the backlighted droplets. An automatic image analysis system was used to obtain information about the droplets including time between detachments, droplet size, and droplet acceleration. At the boundary between the globular and spray modes, the droplet size varies between small droplets that melt off faster than average, resulting in a smaller electrode extension, and large droplets that melt off slower than average, resulting in an increase in the electrode extension. 5 refs., 4 figs., 2 tabs.

  13. Mechanical Characteristics of Submerged Arc Weldment in API Gas Pipeline Steel of Grade X65

    SciTech Connect (OSTI)

    Hashemi, S. H. [Department of Mechanical Engineering, University of Birjand, POBOX 97175-376, Birjand (Iran, Islamic Republic of); Mohammadyani, D. [Materials and Energy Research Center (MERC) POBOX 14155-4777, Tehran (Iran, Islamic Republic of)

    2011-01-17T23:59:59.000Z

    The mechanical properties of submerged arc weldment (SAW) in gas transportation pipeline steel of grade API X65 (65 ksi yield strength) were investigated. This steel is produced by thermo mechanical control rolled (TMC), and is largely used in Iran gas piping systems and networks. The results from laboratory study on three different regions; i.e. base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) were used to compare weldment mechanical characteristics with those specified by API 5L (revision 2004) standard code. Different laboratory experiments were conducted on test specimens taken from 48 inch outside diameter and 14.3 mm wall thickness gas pipeline. The test results showed a gradient of microstructure and Vickers hardness data from the centerline of FZ towards the unaffected MB. Similarly, lower Charpy absorbed energy (compared to BM) was observed in the FZ impact specimens. Despite this, the API specifications were fulfilled in three tested zones, ensuring pipeline structural integrity under working conditions.

  14. Crystalline mesoporous tungsten oxide nanoplate monoliths synthesized by directed soft template method for highly sensitive NO{sub 2} gas sensor applications

    SciTech Connect (OSTI)

    Hoa, Nguyen Duc, E-mail: ndhoa@itims.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) (Viet Nam); Duy, Nguyen Van [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) (Viet Nam)] [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) (Viet Nam); Hieu, Nguyen Van, E-mail: hieu@itims.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) (Viet Nam)

    2013-02-15T23:59:59.000Z

    Graphical abstract: Display Omitted Highlights: ? Mesoporous WO{sub 3} nanoplate monoliths were obtained by direct templating synthesis. ? Enable effective accession of the analytic molecules for the sensor applications. ? The WO{sub 3} sensor exhibited a high performance to NO{sub 2} gas at low temperature. -- Abstract: Controllable synthesis of nanostructured metal oxide semiconductors with nanocrystalline size, porous structure, and large specific surface area is one of the key issues for effective gas sensor applications. In this study, crystalline mesoporous tungsten oxide nanoplate-like monoliths with high specific surface areas were obtained through instant direct-templating synthesis for highly sensitive nitrogen dioxide (NO{sub 2}) sensor applications. The copolymer soft template was converted into a solid carbon framework by heat treatment in an inert gas prior to calcinations in air to sustain the mesoporous structure of tungsten oxide. The multidirectional mesoporous structures of tungsten oxide with small crystalline size, large specific surface area, and superior physical characteristics enabled the rapid and effective accession of analytic gas molecules. As a result, the sensor response was enhanced and the response and recovery times were reduced, in which the mesoporous tungsten oxide based gas sensor exhibited a superior response of 21,155% to 5 ppm NO{sub 2}. In addition, the developed sensor exhibited selective detection of low NO{sub 2} concentration in ammonia and ethanol at a low temperature of approximately 150 °C.

  15. High-power laser and arc welding of thorium-doped iridium alloys

    SciTech Connect (OSTI)

    David, S.A.; Liu, C.T.

    1980-05-01T23:59:59.000Z

    The arc and laser weldabilities of two Ir-0.3% W alloys containing 60 and 200 wt ppM Th have been investigated. The Ir-.03% W alloy containing 200 wt ppM Th is severely prone to hot cracking during gas tungsten-arc welding. Weld metal cracking results from the combined effects of heat-affected zone liquation cracking and solidification cracking. Scanning electron microscopic analysis of the fractured surface revealed patches of low-melting eutectic. The cracking is influenced to a great extent by the fusion zone microstructure and thorium content. The alloy has been welded with a continuous-wave high-power CO/sub 2/ laser system with beam power ranging from 5 to 10 kW and welding speeds of 8 to 25 mm/s. Successful laser welds without hot cracking have been obtained in this particular alloy. This is attributable to the highly concentrated heat source available in the laser beam and the refinement in fusion zone microstructure obtained during laser welding. Efforts to refine the fusion zone structure during gas tungsten-arc welding of Ir-0.3 % W alloy containing 60 wt ppM Th were partially successful. Here transverse arc oscillation during gas tungsten-arc welding refines the fusion zone structure to a certain extent. However, microstructural analysis of this alloy's laser welds indicates further refinement in the fusion zone microstructure than in that from the gas tungsten-arc process using arc oscillations. The fusion zone structure of the laser weld is a strong function of welding speed.

  16. Exhaust gas fuel reforming of Diesel fuel by non-thermal arc discharge for NOx trap regeneration

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Exhaust gas fuel reforming of Diesel fuel by non- thermal arc discharge for NOx trap regeneration to the reforming of Diesel fuel with Diesel engine exhaust gas using a non-thermal plasma torch for NOx trap Diesel fuel reforming with hal-00617141,version1-17May2013 Author manuscript, published in "Energy

  17. Contrib. Plasma Phys. 51, No. 2-3, 293 296 (2011) / DOI 10.1002/ctpp.201000061 LTE Experimental Validation in a Gas Metal Arc Welding Plasma

    E-Print Network [OSTI]

    2011-01-01T23:59:59.000Z

    Validation in a Gas Metal Arc Welding Plasma Column F. Valensi1,2 , S. Pellerin1 , A. Boutaghane3 , K, France 7 CTAS-Air Liquide Welding, Saint Ouen l'Aum^one, 95315 Cergy-Pontoise cedex, France Received 12 Spectroscopy, Boltzmann Plot, Sola method, LTE. During gas metal arc welding (GMAW), the plasma obtained has

  18. A two-dimensional thermomechanical simulation of a gas metal arc welding process

    SciTech Connect (OSTI)

    Ortega, A.R.

    1990-08-01T23:59:59.000Z

    A low heat input gas metal arc (GMA) weld overlay process is being investigated as a possible means to repair Savannah River nuclear reactor tanks in the event cracks are detected in the reactor walls. Two-dimensional thermomechanical simulations of a GMA welding process were performed using the finite element code ABAQUS to assist in the design of the upcoming weld experiments on helium-charged specimens. The thermal model correlated well with existing test data, i.e., fusion zone depth and thermocouple data. In addition, numerical results revealed that after cool-down the final deformation of the workpiece was qualitatively similar to the shape observed experimentally. Based on these analyses, conservative recommendations were made for the workpiece dimensions, weld pass spacing, and thermomechanical boundary conditions to ensure the experiments would be as representative as possible of welding on the reactor walls. 12 refs., 13 figs.

  19. Multiphysics Modeling and Simulations of Mil A46100 Armor-Grade Martensitic Steel Gas Metal Arc Welding

    E-Print Network [OSTI]

    Grujicic, Mica

    Welding Process M. Grujicic, S. Ramaswami, J.S. Snipes, C.-F. Yen, B.A. Cheeseman, and J.S. Montgomery developed for the conventional Gas Metal Arc Welding (GMAW) joining process and used to analyze butt-welding modules, each covering a specific aspect of the GMAW process, i.e., (a) dynamics of welding-gun behavior

  20. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED MELDING PROCESSES IN RELATION TO THE ARC CURRENT DENSITY A Thesis by ROBIN KENT DEVORE Submitted to the Graduate College of Texas A&M University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT...

  1. Plasma diagnostics in gas metal arc welding by optical emission spectroscopy This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Plasma diagnostics in gas metal arc welding by optical emission spectroscopy This article has been welding by optical emission spectroscopy F Valensi1,2 , S Pellerin1 , A Boutaghane3 , K Dzierzega4 de Bourges), BP 4043, 18028 Bourges cedex, France 7 CTAS-Air Liquide Welding, Saint Ouen l

  2. Laser Assisted Plasma Arc Welding

    SciTech Connect (OSTI)

    FUERSCHBACH,PHILLIP W.

    1999-10-05T23:59:59.000Z

    Experiments have been performed using a coaxial end-effecter to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (< 1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  3. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density 

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT... DENSITY A Thesis by ROBIN KENT DEVORE Approved as to style and content by: C alarm n of o itte Hea o partment e er Member December 1973 ABSTRACT The Effective Spectral Irradiance of Ultraviolet Radiations from Inert-Gas-Shielded Welding...

  4. Using ArcGIS to extrapolate greenhouse gas emissions on the Pengxi River, a tributary of the Three Gorges Reservoir in China

    E-Print Network [OSTI]

    Yasarer, Lindsey

    2014-11-19T23:59:59.000Z

    Using ArcGIS to extrapolate greenhouse gas emissions on the Pengxi River, a tributary of the Three Gorges Reservoir in China Lindsey MW Yasarer, PhD Candidate, University of Kansas Dr. Zhe Li, Associate Professor, Chongqing University Dr...D Student, Chongqing University • Zhengyu Zhang and Xiao Yao, Masters Students, Chongqing University • CSTEC: China Science and Technology Exchange Center • NSF EAPSI Program The research was funded by the National Natural Science Foundation of China...

  5. G.M. Wright, VLT Highlight, March 28, 2012 Growth of tungsten nano-tendrils in

    E-Print Network [OSTI]

    1 G.M. Wright, VLT Highlight, March 28, 2012 Growth of tungsten nano-tendrils in the Alcator C morphology of a tungsten divertor modify into fuzz under Helium bombardment in ITER and reactors?! · Linear fragile nano-tendrils! · Increased unipolar arcing! · Likely higher net erosion and W dust production

  6. Laser assisted arc welding for aluminum alloys

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    2000-01-01T23:59:59.000Z

    Experiments have been performed using a coaxial end-effector to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (<1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  7. Novel Reactor Design and Metrology Study for Tungsten ALD process

    E-Print Network [OSTI]

    Rubloff, Gary W.

    species Viscous flow condition Short gas residence time Fast gas switching Reactant + carrier gas Multiple Operation Modes Exposure Purge Small reactor volume Throttle Valve 5 torr 10-5 Torr carrier gas 5 torr 10Novel Reactor Design and Metrology Study for Tungsten ALD process Laurent Henn-Lecordier, Wei Lei

  8. Purification of tantalum by plasma arc melting

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Korzekwa, Deniece R. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    Purification of tantalum by plasma arc melting. The level of oxygen and carbon impurities in tantalum was reduced by plasma arc melting the tantalum using a flowing plasma gas generated from a gas mixture of helium and hydrogen. The flowing plasma gases of the present invention were found to be superior to other known flowing plasma gases used for this purpose.

  9. Narrow groove welding gas diffuser assembly and welding torch

    DOE Patents [OSTI]

    Rooney, Stephen J. (East Berne, NY)

    2001-01-01T23:59:59.000Z

    A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes a manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

  10. Modeling Arcs

    SciTech Connect (OSTI)

    Insepov, Z.; Norem, J. [Argonne National Lab, Argonne, IL 60439 (United States); Vetizer, S.; Mahalingam, S. [Tech-X Corp., Boulder, CO (United States)

    2011-12-23T23:59:59.000Z

    Although vacuum arcs were first identified over 110 years ago, they are not yet well understood. We have since developed a model of breakdown and gradient limits that tries to explain, in a self-consistent way: arc triggering, plasma initiation, plasma evolution, surface damage and gradient limits. We use simple PIC codes for modeling plasmas, molecular dynamics for modeling surface breakdown, and surface damage, and mesoscale surface thermodynamics and finite element electrostatic codes for to evaluate surface properties. Since any given experiment seems to have more variables than data points, we have tried to consider a wide variety of arcing (rf structures, e beam welding, laser ablation, etc.) to help constrain the problem, and concentrate on common mechanisms. While the mechanisms can be comparatively simple, modeling can be challenging.

  11. Tungsten Cathode Catalyst for PEMFC

    SciTech Connect (OSTI)

    Joel B. Christian; Sean P. E. Smith

    2006-09-22T23:59:59.000Z

    Final report for project to evaluate tungsten-based catalyst as a cathode catalyst for PEM cell applications.

  12. Influence of nitrogen in the shielding gas on corrosion resistance of duplex stainless steel welds

    SciTech Connect (OSTI)

    Bhatt, R.B.; Kamat, H.S.; Ghosal, S.K.; De, P.K.

    1999-10-01T23:59:59.000Z

    The influence of nitrogen in shielding gas on the corrosion resistance of welds of a duplex stainless steel (grade U-50), obtained by gas tungsten arc (GTA) with filler wire, autogenous GTA (bead-on-plate), electron beam welding (EBW), and microplasma techniques, has been evaluated in chloride solutions at 30 C. Pitting attack has been observed in GTA, electron beam welding, and microplasma welds when welding has been carried out using pure argon as the shielding gas. Gas tungsten arc welding with 5 to 10% nitrogen and 90 to 95% argon, as the shielding gas, has been found to result in an improved pitting corrosion resistance of the weldments of this steel. However, the resistance of pitting of autogenous welds (bead-on-plate) obtained in pure argon as the shielding gas has been observed to remain unaffected. Microscopic examination, electron probe microanalysis (EPMA), and x-ray diffraction studies have revealed that the presence of nitrogen in the shielding gas in the GTA welds not only modifies the microstructure and the austenite to ferrite ratio but also results in a nearly uniform distribution of the various alloying elements, for example, chromium, nickel, and molybdenum among the constituent phases, which are responsible for improved resistance to pitting corrosion.

  13. Aluminum-tungsten fiber composites with cylindrical geometry and controlled architecture of tungsten reinforcement

    E-Print Network [OSTI]

    Lucchese, Carl Joesph

    2010-01-01T23:59:59.000Z

    Measurements in Alumina and Tungsten Fibre-Reinforcedto-Ductile Transition in Tungsten Single Crystals. ” ScienceToughness of Polycrystalline Tungsten Under Mode I and Mixed

  14. Systematic studies of the nucleation and growth of ultrananocrystalline diamond films on silicon substrates coated with a tungsten layer

    SciTech Connect (OSTI)

    Chu, Yueh-Chieh; Jiang, Gerald [Institute of Microelectronics, No.1, University Road, Tainan 701, Taiwan (China); Tu, Chia-Hao [Institute of Nanotechnology and Microsystems Engineering, No.1, University Road, Tainan 701, Taiwan (China); Department of Materials Science and Engineering, National Cheng Kung University, No.1, University Road, Tainan 701, Taiwan (China); Chang Chi [Institute of Nanotechnology and Microsystems Engineering, No.1, University Road, Tainan 701, Taiwan (China); Liu, Chuan-pu; Ting, Jyh-Ming [Department of Materials Science and Engineering, National Cheng Kung University, No.1, University Road, Tainan 701, Taiwan (China); Lee, Hsin-Li [Industrial Technology Research Institute - South, Tainan 701, Taiwan (China); Tzeng, Yonhua [Institute of Microelectronics, No.1, University Road, Tainan 701, Taiwan (China); Advanced Optoelectronics Technology Center, No.1, University Road, Tainan 701, Taiwan (China); Auciello, Orlando [Argonne National Laboratory, Materials Science Division, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States)

    2012-06-15T23:59:59.000Z

    We report on effects of a tungsten layer deposited on silicon surface on the effectiveness for diamond nanoparticles to be seeded for the deposition of ultrananocrystalline diamond (UNCD). Rough tungsten surface and electrostatic forces between nanodiamond seeds and the tungsten surface layer help to improve the adhesion of nanodiamond seeds on the tungsten surface. The seeding density on tungsten coated silicon thus increases. Tungsten carbide is formed by reactions of the tungsten layer with carbon containing plasma species. It provides favorable (001) crystal planes for the nucleation of (111) crystal planes by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) in argon diluted methane plasma and further improves the density of diamond seeds/nuclei. UNCD films grown at different gas pressures on tungsten coated silicon which is pre-seeded by nanodiamond along with heteroepitaxially nucleated diamond nuclei were characterized by Raman scattering, field emission-scanning electron microscopy, and high resolution-transmission electron microscopy.

  15. High pressure neon arc lamp

    DOE Patents [OSTI]

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15T23:59:59.000Z

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  16. Metals purification by improved vacuum arc remelting

    DOE Patents [OSTI]

    Zanner, Frank J. (Sandia Park, NM); Williamson, Rodney L. (Albuquerque, NM); Smith, Mark F. (Albuquerque, NM)

    1994-12-13T23:59:59.000Z

    The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

  17. Tungsten spectroscopy relevant to the diagnostics development of ITER divertor plasmas

    SciTech Connect (OSTI)

    Clementson, J; Beiersdorfer, P; Magee, E W; McLean, H S; Wood, R D

    2009-12-01T23:59:59.000Z

    The ITER tokamak will have tungsten divertor tiles and, consequently, the divertor plasmas are expected to contain tungsten ions. The spectral emission from these ions can serve to diagnose the divertor for plasma parameters such as tungsten concentrations, densities, ion and electron temperatures, and flow velocities. The ITER divertor plasmas will likely have densities around 10{sup 14-15} cm{sup -3} and temperatures below 150 eV. These conditions are similar to the plasmas at the Sustained Spheromak Physics Experiment (SSPX) in Livermore. To simulate ITER divertor plasmas, a tungsten impurity was introduced into the SSPX spheromak by prefilling it with tungsten hexacarbonyl prior to the usual hydrogen gas injection and initiation of the plasma discharge. The possibility of using the emission from low charge state tungsten ions to diagnose tokamak divertor plasmas has been investigated using a high-resolution extreme ultraviolet spectrometer.

  18. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1987-11-17T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.

  19. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA)

    1987-01-01T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  20. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1985-08-05T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  1. Plasma transferred arc repair welding of the nickel-base superalloy IN-738LC

    SciTech Connect (OSTI)

    Su, C.Y.; Chou, C.P. [National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Dept. of Mechanical Engineering; Wu, B.C.; Lih, W.C. [Industrial Technology Research Inst., Hsinchu (Taiwan, Province of China). Materials Research Labs.

    1997-10-01T23:59:59.000Z

    Plasma transferred arc welding (PTA) has been considered a promising process to restore worn areas of land-based gas turbine blades and vanes. The objective of this investigation was to study the effect of PTA welding on the repairing of IN-738LC superalloy components. Tensile tests were conducted on specimens welded with various combinations of parameters. Room temperature, 760 C, and 980 C were selected as tensile test temperatures. High-temperature phase transformed, during solidification, were identified by differential thermal analysis (DTA). The weld-pool shapes and microstructures of welded specimens prepared by various welding parameters were evaluated by optical metallography (OM), a scanning electron microscope (SEM) equipped with energy dispersive x-ray spectrometer (EDS), and microhardness testing. Results of this study showed that PTA welded specimens exhibited 96% nominal tensile strength of IN-738LC base materials. Specimen failure was observed predominantly in the base materials instead of in the heat-affected zone (HAZ) for gas tungsten arc weld (GTAW) repair weldments. IN-738LC is considered susceptible to weld cracking during fusion welding; however, using a low-input repair welding process (PTA), cracking susceptibility could be minimized by the optimized welding parameters.

  2. Helium bubble bursting in tungsten

    SciTech Connect (OSTI)

    Sefta, Faiza [University of California, Berkeley, California 94720 (United States); Juslin, Niklas [University of Tennessee, Knoxville, Tennessee 37996 (United States); Wirth, Brian D., E-mail: bdwirth@utk.edu [University of Tennessee, Oak Ridge National Laboratory, Knoxville, Tennessee 37996 (United States)

    2013-12-28T23:59:59.000Z

    Molecular dynamics simulations have been used to systematically study the pressure evolution and bursting behavior of sub-surface helium bubbles and the resulting tungsten surface morphology. This study specifically investigates how bubble shape and size, temperature, tungsten surface orientation, and ligament thickness above the bubble influence bubble stability and surface evolution. The tungsten surface is roughened by a combination of adatom “islands,” craters, and pinholes. The present study provides insight into the mechanisms and conditions leading to various tungsten topology changes, which we believe are the initial stages of surface evolution leading to the formation of nanoscale fuzz.

  3. Preparation, Characterization, and Catalytic Properties of Tungsten...

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

    Preparation, Characterization, and Catalytic Properties of Tungsten Trioxide Cyclic Trimers on FeO(111)Pt(111). Preparation, Characterization, and Catalytic Properties of Tungsten...

  4. Comproportionation of Cationic and Anionic Tungsten Complexes...

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

    Comproportionation of Cationic and Anionic Tungsten Complexes Having an N-Heterocyclic Carbene Ligand to Give the Isolable 17 Comproportionation of Cationic and Anionic Tungsten...

  5. The noble gas and carbon systematics of divergent, convergent and strike-slip plate boundaries : examples from the Reykjanes Ridge, Central American Arc and North Anatolian Fault Zone

    E-Print Network [OSTI]

    Leeuw, Goverdina Anna Maria de

    2007-01-01T23:59:59.000Z

    arc. Contrib. Mineral. Petrol. , 105, 369–380. Carr, M. J. ,to degassing. J. Petrol. , 36, 1633–1646. Dixon, J. E. ,and solubility models. J. Petrol. , 36, 1607–1631. Doremus,

  6. THE PHYSICS OF ARC WELDING PROCESSES Department of Materials Science and Engineering,

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) THE PHYSICS OF ARC WELDING PROCESSES T.W.EAGAR Department of Materials Science and Engineering, Massachusetts Institute of Technology Abstract Welding is an extremely complex proce ss; however, due to its Wor ds: Arc Welding, Arc Physics, Shielding Gases, Gas Metal Arc Welding. 1. Introduction Langmuir

  7. Preparation of tungsten oxide

    DOE Patents [OSTI]

    Bulian, Christopher J. (Yankton, SD); Dye, Robert C. (Los Alamos, NM); Son, Steven F. (Los Alamos, NM); Jorgensen, Betty S. (Jemez Springs, NM); Perry, W. Lee (Jemez Springs, NM)

    2009-09-22T23:59:59.000Z

    Tungsten trioxide hydrate (WO.sub.3.H.sub.2O) was prepared from a precursor solution of ammonium paratungstate in concentrated aqueous hydrochloric acid. The precursor solution was rapidly added to water, resulting in the crash precipitation of a yellow white powder identified as WO.sub.3.H.sub.2O nanosized platelets by x-ray diffraction and scanning electron microscopy. Annealing of the powder at 200.degree. C. provided cubic phase WO.sub.3 nanopowder, and at 400.degree. C. provided WO.sub.3 nanopowder as a mixture of monoclinic and orthorhombic phases.

  8. Molybdenum-copper and tungsten-copper alloys and method of making

    DOE Patents [OSTI]

    Schmidt, Frederick A. (Ames, IA); Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA)

    1989-05-23T23:59:59.000Z

    Molybdenum-copper and tungsten-copper alloys are prepared by a consumable electrode method in which the electrode consists of a copper matrix with embedded strips of refractory molybdenum or tungsten. The electrode is progressively melted at its lower end with a superatmospheric inert gas pressure maintained around the liquifying electrode. The inert gas pressure is sufficiently above the vapor pressure of copper at the liquidus temperature of the alloy being formed to suppress boiling of liquid copper.

  9. Molybdenum-copper and tungsten-copper alloys and method of making

    DOE Patents [OSTI]

    Schmidt, F.A.; Verhoeven, J.D.; Gibson, E.D.

    1989-05-23T23:59:59.000Z

    Molybdenum-copper and tungsten-copper alloys are prepared by a consumable electrode method in which the electrode consists of a copper matrix with embedded strips of refractory molybdenum or tungsten. The electrode is progressively melted at its lower end with a superatmospheric inert gas pressure maintained around the liquefying electrode. The inert gas pressure is sufficiently above the vapor pressure of copper at the liquidus temperature of the alloy being formed to suppress boiling of liquid copper. 6 figs.

  10. High strength uranium-tungsten alloys

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Sheinberg, Haskell (Los Alamos, NM); Hogan, Billy M. (Los Alamos, NM); Lewis, Homer D. (Bayfield, CO); Dickinson, James M. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    Alloys of uranium and tungsten and a method for making the alloys. The amount of tungsten present in the alloys is from about 4 wt % to about 35 wt %. Tungsten particles are dispersed throughout the uranium and a small amount of tungsten is dissolved in the uranium.

  11. High strength uranium-tungsten alloy process

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Sheinberg, Haskell (Los Alamos, NM); Hogan, Billy M. (Los Alamos, NM); Lewis, Homer D. (Bayfield, CO); Dickinson, James M. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    Alloys of uranium and tungsten and a method for making the alloys. The amount of tungsten present in the alloys is from about 4 wt % to about 35 wt %. Tungsten particles are dispersed throughout the uranium and a small amount of tungsten is dissolved in the uranium.

  12. anisotropic gas diffusion: Topics by E-print Network

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

    2014 Keywords: Low-temperature combustion syn- thesis Tungsten carbide Electrocatalyst Gas diffusion electrode a b s t r a c t Tungsten carbide powder, which is used as the...

  13. Experimental and theoretical study of exhaust gas fuel reforming of Diesel fuel by a non-thermal arc discharge for syngas production

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -thermal arc discharge for syngas production A. Lebouvier1,2 , F. Fresnet2 , F. Fabry1 , V. Boch2 , V. Rohani1% and a conversion rate of 95% have been reached which correspond to a syngas dry molar fraction of 25%. For the most and promote H2O and CO2 production. Keywords: Plasma reformer, syngas, diesel fuel reforming, NOx trap. 1

  14. Discovery of the Tungsten Isotopes

    E-Print Network [OSTI]

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

    2009-03-25T23:59:59.000Z

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

  15. Discovery of the tungsten isotopes

    SciTech Connect (OSTI)

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

    2010-05-15T23:59:59.000Z

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

  16. Discovery of the Tungsten Isotopes

    E-Print Network [OSTI]

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

    2009-01-01T23:59:59.000Z

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

  17. Molecular dynamics simulation of erosion and surface evolution of tungsten due to bombardment with deuterium and carbon in

    E-Print Network [OSTI]

    Harilal, S. S.

    Simultaneous carbon and deuterium bombardment Hydrogen bubble formation Tungsten sputtering yield a b s t r a c. Carbon pre-irradiated tungsten tends to trap more hydrogen and facilitates gas bubble formation with deuterium and carbon in Tokamak fusion environments Xue Yang , Ahmed Hassanein Center for Material under

  18. Rotating arc spark plug

    DOE Patents [OSTI]

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27T23:59:59.000Z

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  19. DC arc weld starter

    DOE Patents [OSTI]

    Campiotti, Richard H. (Tracy, CA); Hopwood, James E. (Oakley, CA)

    1990-01-01T23:59:59.000Z

    A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.

  20. Process Of Bonding Copper And Tungsten

    DOE Patents [OSTI]

    Slattery, Kevin T. (St. Charles, MO); Driemeyer, Daniel E. (Manchester, MO); Davis, John W. (Ballwin, MO)

    2000-07-18T23:59:59.000Z

    Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by sintering a stack of individual copper and tungsten powder blend layers having progressively higher copper content/tungsten content, by volume, ratio values in successive powder blend layers in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

  1. Tungsten diffusion in silicon

    SciTech Connect (OSTI)

    De Luca, A.; Texier, M.; Burle, N.; Oison, V.; Pichaud, B. [Aix-Marseille Université, IM2NP UMR 7334, Faculté des Sciences et Techniques, Campus de Saint-Jérôme, Avenue Escadrille Normandie Niemen - Case 142, F-13397 Marseille Cedex (France); Portavoce, A., E-mail: alain.portavoce@im2np.fr [CNRS, IM2NP UMR 7334, Faculté des Sciences et Techniques, Campus de Saint-Jérôme, Avenue Escadrille Normandie Niemen - Case 142, F-13397 Marseille Cedex (France); Grosjean, C. [STMicroelectronics, Rousset (France)

    2014-01-07T23:59:59.000Z

    Two doses (10{sup 13} and 10{sup 15}?cm{sup ?2}) of tungsten (W) atoms were implanted in different Si(001) wafers in order to study W diffusion in Si. The samples were annealed or oxidized at temperatures between 776 and 960?°C. The diffusion profiles were measured by secondary ion mass spectrometry, and defect formation was studied by transmission electron microscopy and atom probe tomography. W is shown to reduce Si recrystallization after implantation and to exhibit, in the temperature range investigated, a solubility limit close to 0.15%–0.2%, which is higher than the solubility limit of usual metallic impurities in Si. W diffusion exhibits unusual linear diffusion profiles with a maximum concentration always located at the Si surface, slower kinetics than other metals in Si, and promotes vacancy accumulation close to the Si surface, with the formation of hollow cavities in the case of the higher W dose. In addition, Si self-interstitial injection during oxidation is shown to promote W-Si clustering. Taking into account these observations, a diffusion model based on the simultaneous diffusion of interstitial W atoms and W-Si atomic pairs is proposed since usual models used to model diffusion of metallic impurities and dopants in Si cannot reproduce experimental observations.

  2. Spectroscopic characterization and imaging of laser- and unipolar arc-induced plasmas

    SciTech Connect (OSTI)

    Aussems, Damien U. B., E-mail: d.aussems@differ.nl [FOM Institute DIFFER—Dutch Institute for Fundamental Energy Research, Nieuwegein, NL-3430 BE (Netherlands); Nishijima, Daisuke; Brandt, Christian; Doerner, Russell P. [Center for Energy Research, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093-0417 (United States); Cardozo, Niek J. Lopes [Science and Technology of Nuclear Fusion, Eindhoven University of Technology, Eindhoven 5612 AZ (Netherlands)

    2014-08-14T23:59:59.000Z

    Tungsten plasmas induced by unipolar arcs were investigated using optical emission spectroscopy and imaging, and compared with laser-induced tungsten plasmas. The unipolar arcs were initiated in the linear-plasma simulator PISCES-A at UCSD under fusion relevant conditions. The electron temperature and density of the unipolar arc plasmas were in the range 0.5–0.7?eV and 0.7–2.0?×?10{sup 20?}m{sup ?3}, respectively, and increased with increasing negative bias voltage, but did not correlate with the surface temperature. In comparison, the electron temperature and density of the laser-induced plasmas were in the range 0.6–1.4?eV and 7?×?10{sup 19}–1?×?10{sup 22?}m{sup ?3}, respectively.

  3. Arc initiation in cathodic arc plasma sources

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA)

    2002-01-01T23:59:59.000Z

    A "triggerless" arc initiation method and apparatus is based on simply switching the arc supply voltage to the electrodes (anode and cathode). Neither a mechanical trigger electrode nor a high voltage flashover from a trigger electrode is required. A conducting path between the anode and cathode is provided, which allows a hot spot to form at a location where the path connects to the cathode. While the conductive path is eroded by the cathode spot action, plasma deposition ensures the ongoing repair of the conducting path. Arc initiation is achieved by simply applying the relatively low voltage of the arc power supply, e.g. 500 V-1 kV, with the insulator between the anode and cathode coated with a conducting layer and the current at the layer-cathode interface concentrated at one or a few contact points. The local power density at these contact points is sufficient for plasma production and thus arc initiation. A conductive surface layer, such as graphite or the material being deposited, is formed on the surface of the insulator which separates the cathode from the anode. The mechanism of plasma production (and arc initiation) is based on explosive destruction of the layer-cathode interface caused by joule heating. The current flow between the thin insulator coating and cathode occurs at only a few contact points so the current density is high.

  4. Method of synthesizing tungsten nanoparticles

    SciTech Connect (OSTI)

    Thoma, Steven G; Anderson, Travis M

    2013-02-12T23:59:59.000Z

    A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

  5. Arc Position Sensing Technology

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

    arc remelting (VAR) furnaces for industries that use specialty metals such as nickel, titanium, and zirconium. The technology could be used to help produce materials with stronger...

  6. Process Of Bonding Copper And Tungsten

    DOE Patents [OSTI]

    Slattery, Kevin T. (St. Charles, MO); Driemeyer, Daniel E. (Manchester, MO)

    1999-11-23T23:59:59.000Z

    Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by thermal plasma spraying mixtures of copper powder and tungsten powder in a varied blending ratio such that the blending ratio of the copper powder and the tungsten powder that is fed to a plasma torch is intermittently adjusted to provide progressively higher copper content/tungsten content, by volume, ratio values in the interlayer in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

  7. Accepted Manuscript Making Tungsten Work

    E-Print Network [OSTI]

    Raffray, A. René

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Center at MIT International Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of choice in several design

  8. Diffusion of tungsten clusters on tungsten (110) surface

    SciTech Connect (OSTI)

    Chen, Dong; Hu, Wangyu; Yang, Jianyu; Deng, Huiqiu; Sun, Lixian; Gao, Fei

    2009-04-01T23:59:59.000Z

    Using molecular dynamics simulation and modified analytic embedded-atom method, we have investigated the self-diffusion of clusters on a tungsten (110) surface. As compared to the linear-chain configuration, the close-packed islands for tungsten clusters containing more than nine adatoms have been predicted to be more stable with the relatively lower binding energies. The migration energies show an interesting and oscillating behavior with increasing cluster size. The tetramer, hexamer and octamer have obviously higher migration energies than the others. The different atomic configurations and diffusion mechanisms have been determined during the diffusion processes. It is clear that the dimer-shearing mechanism occurs inside the hexamer, while it occurs at the periphery of heptamer. The successive hopping mechanism of individual atom is of critical importance in the migration of the clusters containing five or fewer adatoms. In addition, the diffusion of a cluster with nine adatoms is achieved through the changes of the cluster shape.

  9. Low-temperature chemical vapor deposition of tungsten from tungsten hexacarbonyl

    SciTech Connect (OSTI)

    Vogt, G.J.

    1982-04-01T23:59:59.000Z

    Chemical vapor deposition (CVD) of tungsten from W(CO)/sub 6/ has been investigated below 670 K as an alternate process to WF/sub 6/ CVD for coating glass microspheres. The major advantages of W(CO)/sub 6/ CVD are the elimination of the HF damage to the glass microspheres and potentially a lower deposition temperature for coating DT-filled microspheres. W(CO)/sub 6/ CVD can be utilized, in principle, to coat the microspheres with 1 to 5 ..mu..m of tungsten or to flash coat the microspheres for further coating by WF/sub 6/ CVD. Test coatings were deposited in a fluidized-bed reactor with a hydrogen carrier gas. The coatings were found to contain nearly equal portions of carbon and oxygen, ranging from 16 to 25 at.% for each element. The high carbon and oxygen concentrations are believed to result principally from the physical entrapment of chemisorbed CO molecules at the surface of the growing deposit. The general quality and adhesion of the W(CO)/sub 6/-derived coatings are unsatisfactory at this time for ICF applications.

  10. Characterization of tungsten films and their hydrogen permeability

    SciTech Connect (OSTI)

    Nemani?, Vincenc, E-mail: vincenc.nemanic@ijs.si; Kova?, Janez [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Lungu, Cristian; Porosnicu, Corneliu [National Institute for Laser, Plasma and Radiation Physics, NILPRP, Magurele, Bucharest 077125 (Romania); Zajec, Bojan [Slovenian National Building and Civil Engineering Institute, Dimi?eva 12, 1000 Ljubljana (Slovenia)

    2014-11-01T23:59:59.000Z

    Prediction of tritium migration and its retention within fusion reactors is uncertain due to a significant role of the structural disorder that is formed on the surface layer after plasma exposure. Tungsten films deposited by any of the suitable methods are always disordered and contain a high density of hydrogen traps. Experiments on such films with hydrogen isotopes present a suitable complementary method, which improves the picture of the hydrogen interaction with fusion relevant materials. The authors report on the morphology, composition, and structure of tungsten films deposited by the thermionic vacuum arc method on highly permeable Eurofer substrates. Subsequently, hydrogen permeation studies through these films were carried out in a wide pressure range from 20 to 1000 mbars at 400?°C. The final value of the permeation coefficient for four samples after 24?h at 400?°C was between P?=?3.2?×?10{sup ?14}?mol?H{sub 2}/(m?s?Pa{sup 0.5}) and P?=?1.1?×?10{sup ?15}?mol H{sub 2}/(m s Pa{sup 0.5}). From the time evolution of the permeation flux, it was shown that diffusivity was responsible for the difference in the steady fluxes, as solubility was roughly the same. This is confirmed by XRD data taken on these samples.

  11. A Well-Defined, Silica-Supported Tungsten Imido Alkylidene Olefin Metathesis Catalyst

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    deactivation. Keywords. Tungsten Imido Alkylidene complex.monosiloxy alkylidene tungsten surface complex syn-2, [(_

  12. Corrosion and arc erosion in MHD channels

    SciTech Connect (OSTI)

    Rosa, R.J. (Montana State Univ., Bozeman, MT (United States). Dept. of Mechanical Engineering); Pollina, R.J. (Montana State Univ., Bozeman, MT (United States). Dept. of Mechanical Engineering EG and G Energy Measurements, Inc., Las Vegas, NV (United States))

    1992-08-01T23:59:59.000Z

    The problems connected with gas side corrosion for the design of the lA4 (POC) channel hardware are explored and results of gas side wear rate tests in the Textron Mark VII facility are presented. It is shown that the proposed designs meet a 2000 hour lifetime criterion based upon these materials tests. Improvement in cathode lifetime is demonstrated with lower voltage intercathode gaps. The corrosion of these materials is discussed and it is shown how lifetimes are dependent upon gap voltage and average metal temperature. The importance of uniformity of slagging to the durability of the anode wall is demonstrated. The wear mechanism of the anodes in the MHD channel is analyzed. In addition to gas-side corrosion, the results of specific water corrosion tests of sidewall materials are discussed. All of the tests reported here were carried out to confirm the gas-side performance and the manufacturability of anode and sidewall designs and to address questions posed about the durability of tungsten-copper on the waterside. the results of water corrosion tests of the tungsten copper alloy sidewall material are presented to show that with proper control of waterside pH and, if necessary, dissolved oxygen, one can obtain reliable performance with no degradation of heat transfer with this material. The final choice of materials was determined primarily by the outcome of these tests and also by the question of the manufacturability of the prospective designs.

  13. Gamma Spectrum from Neutron Capture on Tungsten Isotopes

    E-Print Network [OSTI]

    Hurst, Aaron

    2011-01-01T23:59:59.000Z

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

  14. Factors controlling tungsten concentrations in ground water, Carson Desert, Nevada

    E-Print Network [OSTI]

    Factors controlling tungsten concentrations in ground water, Carson Desert, Nevada Ralph L. Seiler sources. Tungsten concentrations in 100 ground water samples from all aquifers used as drinking water indicates that W exhibits Tungsten con- centrations are strongly and positively correlated

  15. Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111)....

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

    Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111). Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111). Abstract: Ordered tungsten oxide ultra-thin films were...

  16. Effects of Tungsten Oxide Addition on the Electrochemical Performance...

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

    Tungsten Oxide Addition on the Electrochemical Performance of Nanoscale Tantalum Oxide-Based Electrocatalysts for Effects of Tungsten Oxide Addition on the Electrochemical...

  17. May 19-21, 2010 Marrakech, Morocco.

    E-Print Network [OSTI]

    Boyer, Edmond

    Gas' process (TIG), also called Gas Tungsten Arc Welding (GTAW) is a welding process using a tungsten : Morocco (2010)" #12;2 2 Hot tearing phenomenon in welding 2.1 TIG arc welding process The 'Tungsten Inert , a crack created during arc welding on a 6056 aluminum alloy is clearly visible. The purpose

  18. DPA and Gas Production from Protons on W and Be

    E-Print Network [OSTI]

    McDonald, Kirk

    Production in Tungsten · Ran the Mu2e target in MARS15 using the following parameters: ­ 8 GeV protonsDPA and Gas Production from Protons on W and Be Brian Hartsell FNAL March 20, 2013 #12;DPA and Gas on Tungsten target ­ Gaussian distribution with 1mm X and Y sigma ­ 6mm diameter, 160mm length target ­ 3 bins

  19. College of Design ARC Architecture

    E-Print Network [OSTI]

    MacAdam, Keith

    College of Design ARC Architecture KEY: # = new course * = course changed = course dropped,landscape,andarchitecturalspaceswithattentiontotheirapplicationtothearchitecturalexperience.Studio:4hoursperweek. Prereq: Admission to the School of Architecture. ARC 102 DRAWING II: OBSERVATIONAL OF ARCHITECTURE. (3

  20. High strength and density tungsten-uranium alloys

    DOE Patents [OSTI]

    Sheinberg, Haskell (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    Alloys of tungsten and uranium and a method for making the alloys. The amount of tungsten present in the alloys is from about 55 vol % to about 85 vol %. A porous preform is made by sintering consolidated tungsten powder. The preform is impregnated with molten uranium such that (1) uranium fills the pores of the preform to form uranium in a tungsten matrix or (2) uranium dissolves portions of the preform to form a continuous uranium phase containing tungsten particles.

  1. Physical properties of erbium implanted tungsten oxide films deposited by reactive dual magnetron sputtering

    E-Print Network [OSTI]

    Mohamed, Sodky H.; Anders, Andre

    2006-01-01T23:59:59.000Z

    of erbium implanted tungsten oxide films deposited byDual magnetron sputtering; tungsten oxide films; Er ionoptical waveguides [3,5]. Tungsten oxide (WO 3 ) thin films

  2. FINAL FOCUS ION BEAM INTENSITY FROM TUNGSTEN FOIL CALORIMETER AND SCINTILLATOR IN NDCX-I

    E-Print Network [OSTI]

    Lidia, S.M.

    2010-01-01T23:59:59.000Z

    FOCUS ION BEAM INTENSITY FROM TUNGSTEN FOIL CALORIMETER ANDtemperature rise in the tungsten foil. A cross-calibrationis obtained with a 3µm thick tungsten foil calorimeter and

  3. Electrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows

    E-Print Network [OSTI]

    Anders, Andre

    2008-01-01T23:59:59.000Z

    gas-reservoir MnNiMg electrochromic mirror devices have beencontrast to conventional electrochromic approaches, hydrogenThe application of electrochromic devices based on tungsten

  4. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, D.E.; Lee, S.G.

    1996-08-06T23:59:59.000Z

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics. 4 figs.

  5. High-bandwidth continuous-flow arc furnace

    DOE Patents [OSTI]

    Hardt, David E. (Concord, MA); Lee, Steven G. (Ann Arbor, MI)

    1996-01-01T23:59:59.000Z

    A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics.

  6. Automotive Research Center (ARC) "The Automotive Research Center (ARC) develops simulation and modeling tools for discovering

    E-Print Network [OSTI]

    Kamat, Vineet R.

    Automotive Research Center (ARC) "The Automotive Research Center (ARC) develops simulation with industry to leverage and transfer the efforts and results http://arc.engin.umich.edu/ #12;

  7. Influence of process parameters on properties of reactively sputtered tungsten nitride thin films

    SciTech Connect (OSTI)

    Addonizio, Maria L.; Castaldo, Anna; Antonaia, Alessandro; Gambale, Emilia; Iemmo, Laura [ENEA, Portici Research Centre, Piazzale E. Fermi 1, I-80055, Portici (Italy)

    2012-05-15T23:59:59.000Z

    Tungsten nitride (WN{sub x}) thin films were produced by reactive dc magnetron sputtering of tungsten in an Ar-N{sub 2} gas mixture. The influence of the deposition power on the properties of tungsten nitride has been analyzed and compared with that induced by nitrogen content variation in the sputtering gas. A combined analysis of structural, electrical and optical properties on thin WN{sub x} films obtained at different deposition conditions has been performed. It was found that at an N{sub 2} content of 14% a single phase structure of W{sub 2}N films was formed with the highest crystalline content. This sputtering gas composition was subsequently used for fabricating films at different deposition powers. Optical analysis showed that increasing the deposition power created tungsten nitride films with a more metallic character, which is confirmed with resistivity measurements. At low sputtering powers the resulting films were crystalline whereas, with an increase of power, an amorphous phase was also present. The incorporation of an excess of nitrogen atoms resulted in an expansion of the W{sub 2}N lattice and this effect was more pronounced at low deposition powers. Infrared analysis revealed that in WN{sub x} films deposited at low power, chemisorbed N{sub 2} molecules did not behave as ligands whereas at high deposition power they clearly appeared as ligands around metallic tungsten. In this study, the influence of the most meaningful deposition parameters on the phase transformation reaction path was established and deposition conditions suitable for producing thermally stable and highly crystalline W{sub 2}N films were found.

  8. Comparison of Bond Scission Sequence of Methanol on Tungsten Monocarbide and Pt-Modified Tungsten Monocarbide

    SciTech Connect (OSTI)

    Liu, P.; Stottlemyer, A.L.; Chen, J.G.

    2010-09-14T23:59:59.000Z

    The ability to control the bond scission sequence of O-H, C-H, and C-O bonds is of critical importance in the effective utilization of oxygenate molecules, such as in reforming reactions and in alcohol fuel cells. In the current study, we use methanol as a probe molecule to demonstrate the possibility to control the decomposition pathways by supporting monolayer coverage of Pt on a tungsten monocarbide (WC) surface. Density functional theory (DFT) results reveal that on the WC and Pt/WC surfaces CH{sub 3}OH decomposes via O-H bond scission to form the methoxy (*CH{sub 3} O) intermediate. The subsequent decomposition of methoxy on the WC surface occurs through the C-O bond scission to form *CH{sub 3}, which reacts with surface *H to produce CH{sub 4}. In contrast, the decomposition of methoxy on the Pt/WC surface favors the C-H bond scission to produce *CH{sub 2} O, which prevents the formation of the *CH{sub 3} species and leads to the formation of a *CO intermediate through subsequent deprotonation steps. The DFT predictions are validated using temperature programmed desorption to quantify the gas-phase product yields and high resolution electron energy loss spectroscopy to determine the surface intermediates from methanol decomposition on Pt, WC, and Pt/WC surfaces.

  9. TUNGSTEN--2001 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , electrical, heating, and welding applications. Tungsten is also used to make heavy-metal alloys for armaments- temperature lubricants. U.S. apparent consumption of all tungsten materials in 2001 remained approximately

  10. TUNGSTEN--2002 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , electrical, heating, and welding applications. Tungsten is also used to make heavy-metal alloys for armaments, high-temperature lubricants, and semiconductors. U.S. apparent consumption of all tungsten materials

  11. Growth of tungsten oxide on carbon nanowalls templates

    SciTech Connect (OSTI)

    Wang, Hua, E-mail: wanghua@dlou.edu.cn [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023 (China); Su, Yan [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Chen, Shuo, E-mail: shuochen@dlut.edu.cn [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Quan, Xie [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China)

    2013-03-15T23:59:59.000Z

    Highlights: ? Tungsten oxide deposited on carbon nanowalls by hot filament chemical vapor deposition technique. ? This composite has two-dimensional uniform morphology with a crystalline structure of monoclinic tungsten trioxide. ? Surface photoelectric voltage measurements show that this product has photoresponse properties. - Abstract: In the present work we present a simple approach for coupling tungsten oxide with carbon nanowalls. The two-dimensional carbon nanowalls with open boundaries were grown using plasma enhanced hot filament chemical vapor deposition, and the subsequent tungsten oxide growth was performed in the same equipment by direct heating of a tungsten filament. The tungsten oxide coating is found to have uniform morphology with a crystalline structure of monoclinic tungsten trioxide. Surface photoelectric voltage measurements show that this product has photoresponse properties. The method of synthesis described here provides an operable route to the production of two-dimensional tungsten oxide nanocomposites.

  12. Arc Position Sensing

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational Management » History »Dept ofY-12Arah SchuurArc

  13. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1998, little if any tungsten concentrate was produced from U.S. mines.

    E-Print Network [OSTI]

    184 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1998, little if any tungsten concentrate was produced from U.S. mines. Approximately 10 companies in the United States processed tungsten concentrates, ammonium paratungstate, tungsten oxide, and

  14. Element 74, the Wolfram Versus Tungsten Controversy

    SciTech Connect (OSTI)

    Holden,N.E.

    2008-08-11T23:59:59.000Z

    Two and a quarter centuries ago, a heavy mineral ore was found which was thought to contain a new chemical element called heavy stone (or tungsten in Swedish). A few years later, the metal was separated from its oxide and the new element (Z=74) was called wolfram. Over the years since that time, both the names wolfram and tungsten were attached to this element in various countries. Sixty years ago, IUPAC chose wolfram as the official name for the element. A few years later, under pressure from the press in the USA, the alternative name tungsten was also allowed by IUPAC. Now the original, official name 'wolfram' has been deleted by IUPAC as one of the two alternate names for the element. The history of this controversy is described here.

  15. Theoretic Insight into CO2 Reduction at Active Sites of Molybdenum and Tungsten Enzymes: a {\\pi} Interaction between CO2 and Tungsten Bis-Dithiolene Complexes

    E-Print Network [OSTI]

    Yan, Yong

    2014-01-01T23:59:59.000Z

    Active sites of molybdenum and tungsten enzymes, particularly mononuclear tungsten formate dehydrogenase (FDH) have been theoretically investigated towards their interaction with CO2. Obvious {\\pi} interaction has been found between the 2e reduced metallodithiole moiety and the molecular CO2. This weak {\\pi} bonding is predicated both at gas phase, noted as -6.0 kcal/mol and aqueous solvation level, -3.6 kcal/mol. Such interaction is not only limited to CO2, but also to the CO2 reduced product, i.e. formate, in the form of anion- {\\pi} interaction, noted as -6.8 kcal/mol and -4.1 kcal/mol respectively in gas and aqueous solvation model. The Bailar twisted angles from 60o to 0o, governing structure preference of tungsten dithiolene from octahedron to triangle prism in their restricted structures, has been explored to evaluate such {\\pi} in-terrelations with CO2 and formate. An octahedral structure with 3 kcal/mol energy lower is preferred over the triangle prismatic when such interactions are concerned.

  16. TUNGSTEN--2000 81.1 By Kim B. Shedd

    E-Print Network [OSTI]

    TUNGSTEN--2000 81.1 TUNGSTEN By Kim B. Shedd Domestic survey data and tables were prepared by Jason T. Collins, statistical assistant, and the world production table was prepared by Glenn J. Wallace, international data coordinator. Tungsten is a whitish-gray metal with many unique properties and a wide variety

  17. Cathodic Vacuum Arc Plasma of Thallium

    E-Print Network [OSTI]

    Yushkov, Georgy Yu.; Anders, Andre

    2006-01-01T23:59:59.000Z

    P. J. Martin, Handbook of Vacuum Arc Science and Technology.charge state distributions of vacuum arc plasmas: The originand the broadening of vacuum-arc ion charge state

  18. Anode-cathode voltage drop of a rotating arc in an auto-expansion circuit-breaker filled with SF6-N2 mixtures

    SciTech Connect (OSTI)

    Beauvois, V.; Legros, W.; Scarpa, P. [Inst. Montefiore, Liege (Belgium)] [and others

    1995-12-31T23:59:59.000Z

    In auto-expansion circuit-breakers, the power dissipated by the arc itself heats the surrounding gas, inducing a pressure build up in the {open_quotes}upstream volume{close_quotes} and giving rise to a gas flow which blows the extinguishing arc. Moreover, in the studied apparatus, a magnetic field, due to the current flowing in a coil, provides arc radial stability and leads to arc rotation which efficiently reduces electrode erosion. In such a circuit-breaker, it is obvious that arc-gas and arc-electrode interactions are essential and govern. the energy balance in the plasma region. This paper deals more specifically with the phenomena occurring at the arc-electrode interfaces. It relates results of experiments carried out to determine the anode-cathode voltage drop when the apparatus is filled with different SF6-N2 mixtures.

  19. EFFECT OF MINOR ADDITIONS OF HYDROGEN TO ARGON SHIELDING GAS WHEN WELDING AUSTENITIC STAINLESS STEEL WITH THE GTAW PROCESS

    SciTech Connect (OSTI)

    CANNELL, G.R.

    2004-12-15T23:59:59.000Z

    This paper provides the technical basis to conclude that the use of hydrogen containing shielding gases during welding of austenitic stainless steels will not lead to hydrogen induced cracking (HIC) of the weld or weld heat affected zone. Argon-hydrogen gas mixtures, with hydrogen additions up to 35% [1], have been successfully used as the shielding gas in gas tungsten arc welding (GTAW) of austenitic stainless steels. The addition of hydrogen improves weld pool wettability, bead shape control, surface cleanliness and heat input. The GTAW process is used extensively for welding various grades of stainless steel and is preferred when a very high weld quality is desired, such as that required for closure welding of nuclear materials packages. The use of argon-hydrogen gas mixtures for high-quality welding is occasionally questioned, primarily because of concern over the potential for HIC. This paper was written specifically to provide a technical basis for using an argon-hydrogen shielding gas in conjunction with the development, at the Savannah River Technology Center (SRTC), of an ''optimized'' closure welding process for the DOE standardized spent nuclear fuel canister [2]. However, the basis developed here can be applied to other applications in which the use of an argon-hydrogen shielding gas for GTAW welding of austenitic stainless steels is desired.

  20. Arc fault detection system

    DOE Patents [OSTI]

    Jha, Kamal N. (Bethel Park, PA)

    1999-01-01T23:59:59.000Z

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

  1. Arc fault detection system

    DOE Patents [OSTI]

    Jha, K.N.

    1999-05-18T23:59:59.000Z

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

  2. Tungsten Divertor Erosion in all Metal Devices: Lessons from the ITER-Like Wall of JET and the All Tungsten ASDEX Upgrade

    E-Print Network [OSTI]

    Tungsten Divertor Erosion in all Metal Devices: Lessons from the ITER-Like Wall of JET and the All Tungsten ASDEX Upgrade

  3. Corrosion and arc erosion in MHD channels. Final report

    SciTech Connect (OSTI)

    Rosa, R.J. [Montana State Univ., Bozeman, MT (United States). Dept. of Mechanical Engineering; Pollina, R.J. [Montana State Univ., Bozeman, MT (United States). Dept. of Mechanical Engineering]|[EG and G Energy Measurements, Inc., Las Vegas, NV (United States)

    1992-08-01T23:59:59.000Z

    The problems connected with gas side corrosion for the design of the lA4 (POC) channel hardware are explored and results of gas side wear rate tests in the Textron Mark VII facility are presented. It is shown that the proposed designs meet a 2000 hour lifetime criterion based upon these materials tests. Improvement in cathode lifetime is demonstrated with lower voltage intercathode gaps. The corrosion of these materials is discussed and it is shown how lifetimes are dependent upon gap voltage and average metal temperature. The importance of uniformity of slagging to the durability of the anode wall is demonstrated. The wear mechanism of the anodes in the MHD channel is analyzed. In addition to gas-side corrosion, the results of specific water corrosion tests of sidewall materials are discussed. All of the tests reported here were carried out to confirm the gas-side performance and the manufacturability of anode and sidewall designs and to address questions posed about the durability of tungsten-copper on the waterside. the results of water corrosion tests of the tungsten copper alloy sidewall material are presented to show that with proper control of waterside pH and, if necessary, dissolved oxygen, one can obtain reliable performance with no degradation of heat transfer with this material. The final choice of materials was determined primarily by the outcome of these tests and also by the question of the manufacturability of the prospective designs.

  4. 202-s | JUNE 1999 RESEARCH/DEVELOPMENT/RESEARCH/DEVELOPMENT/RESEARCH/DEVELOPMENT/RESEARCH/DEVELOPMENT

    E-Print Network [OSTI]

    Zhang, YuMing

    . In this study, the conventional gas tungsten arc welding process is modified by disconnecting the workpiece from the arcs and improves the weld penetration, thus re- sulting in a reduction in the heat input. This process on productivity, cost and weld quality. In this study, the dual-torch gas tungsten arc welding (GTAW) process

  5. Oxygen and Nitrogen Contamination During Arc Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ) ) : ,- Oxygen and Nitrogen Contamination During Arc Welding T. W. Eagar Department of }faterials, shielded metal arc, self-shielded metal arc, and submerged arc welding are reviewed. Calcu- lations upon heating is also discussed. Introduction Oxygen and nitrogen ~ontamination of weld metal

  6. Tungsten injector for scrape-off layer impurity transport experiments in the Tore Supra tokamak

    SciTech Connect (OSTI)

    Ko?an, M.; Lunt, T. [Max-Planck-Institut für Plasmaphysik, EURATOM Association Boltzmannstr. 2, D-85748 Garching (Germany)] [Max-Planck-Institut für Plasmaphysik, EURATOM Association Boltzmannstr. 2, D-85748 Garching (Germany); Gunn, J. P.; Meyer, O.; Pascal, J.-Y. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)] [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

    2013-07-15T23:59:59.000Z

    This paper describes the design and operation of a new tungsten (W) injection system for impurity transport experiments in the Tore Supra tokamak. The system is mounted on a reciprocating manipulator and injects a controlled amount of gaseous tungsten hexacarbonyl, W(CO){sub 6} at arbitrary depth in the scrape-off layer, using an inertially activated valve. Injected W(CO){sub 6} is dissociated in the plasma, forming a radially localized plume of W atoms. The injector does not require an external gas feed and can perform a large number of injections from an on-board reservoir of W(CO){sub 6}. Some examples of W injections in Tore Supra are included, demonstrating successful operation and discussing some technical issues of the injector prototype.

  7. Percussive arc welding apparatus

    DOE Patents [OSTI]

    Hollar, Jr., Donald L. (Overland Park, KS)

    2002-01-01T23:59:59.000Z

    A percussive arc welding apparatus includes a generally cylindrical actuator body having front and rear end portions and defining an internal recess. The front end of the body includes an opening. A solenoid assembly is provided in the rear end portion in the internal recess of the body, and an actuator shaft assembly is provided in the front end portion in the internal recess of the actuator body. The actuator shaft assembly includes a generally cylindrical actuator block having first and second end portions, and an actuator shaft having a front end extending through the opening in the actuator body, and the rear end connected to the first end portion of the actuator block. The second end portion of the actuator block is in operational engagement with the solenoid shaft by a non-rigid connection to reduce the adverse rebound effects of the actuator shaft. A generally transversely extending pin is rigidly secured to the rear end of the shaft. One end of the pin is received in a slot in the nose housing sleeve to prevent rotation of the actuator shaft during operation of the apparatus.

  8. Formation of metal oxides by cathodic arc deposition

    SciTech Connect (OSTI)

    Anders, S.; Anders, A.; Rubin, M.; Wang, Z.; Raoux, S.; Kong, F.; Brown, I.G.

    1995-03-01T23:59:59.000Z

    Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, an established, industrially applied technique for formation of nitrides (e.g. TiN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with desired cathode material is operated in an oxygen atmosphere, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on ALS components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}/Y{sub 2}O{sub 3}/AI{sub 2}O{sub 3}/Si as possible basic structures for passive optoelectronic integrated circuits, and Al{sub 2-x}Er{sub x}O{sub 3} thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 {mu}m. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells.

  9. Controlled nanostructuration of polycrystalline tungsten thin films

    SciTech Connect (OSTI)

    Girault, B. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), LUNAM Universite, Universite de Nantes, Centrale Nantes, CRTT, 37 Bd de l'Universite, BP 406, 44602 Saint-Nazaire Cedex (France); Eyidi, D.; Goudeau, P.; Guerin, P.; Bourhis, E. Le; Renault, P.-O. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Sauvage, T. [CEMHTI/CNRS (UPR 3079 CNRS), Universite d'Orleans, 3A rue de la Ferollerie, 45071 Orleans Cedex 2 (France)

    2013-05-07T23:59:59.000Z

    Nanostructured tungsten thin films have been obtained by ion beam sputtering technique stopping periodically the growing. The total thickness was maintained constant while nanostructure control was obtained using different stopping periods in order to induce film stratification. The effect of tungsten sublayers' thicknesses on film composition, residual stresses, and crystalline texture evolution has been established. Our study reveals that tungsten crystallizes in both stable {alpha}- and metastable {beta}-phases and that volume proportions evolve with deposited sublayers' thicknesses. {alpha}-W phase shows original fiber texture development with two major preferential crystallographic orientations, namely, {alpha}-W<110> and unexpectedly {alpha}-W<111> texture components. The partial pressure of oxygen and presence of carbon have been identified as critical parameters for the growth of metastable {beta}-W phase. Moreover, the texture development of {alpha}-W phase with two texture components is shown to be the result of a competition between crystallographic planes energy minimization and crystallographic orientation channeling effect maximization. Controlled grain size can be achieved for the {alpha}-W phase structure over 3 nm stratification step. Below, the {beta}-W phase structure becomes predominant.

  10. Tungsten-dependent formaldehyde ferredoxin oxidoreductase: Reaction mechanism from quantum chemical calculations

    E-Print Network [OSTI]

    Liao, Rongzhen

    Tungsten-dependent formaldehyde ferredoxin oxidoreductase: Reaction mechanism from quantum chemical theory Enzyme catalysis Formaldehyde ferredoxin oxidoreductase from Pyrococcus furiosus is a tungsten the formaldehyde substrate binds directly to the tungsten ion. WVI =O then performs a nucleophilic attack

  11. Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2,6-Dimesitylphenylimido

    E-Print Network [OSTI]

    Müller, Peter

    Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2 ABSTRACT: Molybdenum and tungsten bispyrrolide alkyli- dene complexes that contain a 2 those that contain 2,5-dimethylpyrro- lide are pyridine free. Molybdenum and tungsten MAP 2

  12. Investigation of coronal plasma dynamics in tungsten and carbon X-pinches

    E-Print Network [OSTI]

    Madden, Robert Edward

    2008-01-01T23:59:59.000Z

    Coronal Plasma Dynamics in Tungsten and Carbon X-pinches ACoronal Plasma Dynamics in Tungsten and Carbon X-pinches byformation in 2- and 4-wire tungsten x-pinches using an 80

  13. CRITICAL FIELD FOR SUPERCONDUCTIVITY AND LOW-TEMPERATURE NORMAL-STATE HEAT CAPACITY OF TUNGSTEN

    E-Print Network [OSTI]

    Triplett, B.B.

    2008-01-01T23:59:59.000Z

    NORMAL-STATE HEAT CAPACITY OF TUNGSTEN B. B. Triplett, N. E.State Heat Capacity of Tungsten* B. n. Triplett,t N. E.I. ;\\feasurement Properties of tungsten sa~ples. ~feasured

  14. THE As-QUENCHED MICROSTRUCTURE AND TEMPERING BEHAVIOR OF RAPIDLY SOLIDIFIED TUNGSTEN STEELS

    E-Print Network [OSTI]

    Rayment, J.J.

    2014-01-01T23:59:59.000Z

    of six ternary iron-tungsten-carbon alloys and commercialFeWCS-6 (20 and 23wt% tungsten) only the cellular micro-microstructure of the higher tungsten alloys. Selected area

  15. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1997, little if any tungsten concentrate was produced from U.S. mines.

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production in a significant decrease in mine production. The amount of tungsten concentrates remaining in stockpiles in China for the tungsten industry. Once the stockpiles are depleted, world mine production will have to increase to meet

  16. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: Limited shipments of tungsten concentrates were made from a California mine in

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and primary products, wrought and unwrought tungsten, and waste and scrap: China, 43%; Germany, 11%; Canada,630 1,450 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  17. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A tungsten mine in California produced concentrates in 2012. Approximately eight

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 45,200 3,630 1,610 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  18. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: One mine in California produced tungsten concentrates in 2010. Approximately

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production. Import Sources (2006­09): Tungsten contained in ores and concentrates, intermediate and primary products, Trends, and Issues: World tungsten supply is dominated by Chinese production and exports. China

  19. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A mine in California produced tungsten concentrates in 2009. Approximately eight

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production. Import Sources (2005-08): Tungsten contained in ores and concentrates, intermediate and primary products, and Issues: World tungsten supply was dominated by Chinese production and exports. China's Government limited

  20. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A mine in California restarted operations and made its first shipment of tungsten

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and primary products, wrought and unwrought tungsten, and waste and scrap: China, 43%; Canada, 16%; Germany, 9 by Chinese production and exports. China's Government restricted the amounts of tungsten that could

  1. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in 1994 of ores and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste

  2. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in 1994. In 2000, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 39%; Russia, 21

  3. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A tungsten mine in California produced concentrates in 2013. Approximately eight

    E-Print Network [OSTI]

    174 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 45,100 2,300 2,240 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  4. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: One mine in California produced tungsten concentrates in 2011. Approximately

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production (2007­10): Tungsten contained in ores and concentrates, intermediate and primary products, wrought: World tungsten supply is dominated by Chinese production and exports. China's Government regulates its

  5. Tungsten Cluster Migration on Nanoparticles: Minimum Energy Pathway...

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

    Pathway and Migration Mechanism. Tungsten Cluster Migration on Nanoparticles: Minimum Energy Pathway and Migration Mechanism. Abstract: Transition state searches have been...

  6. alkaline tungsten matrix: Topics by E-print Network

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

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of...

  7. anthocyanins facilitate tungsten: Topics by E-print Network

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

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of...

  8. Synthesis of Molybdenum and Tungsten Alkylidene Complexes That Contain Sterically Demanding Arenethiolate Ligands

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis of Molybdenum and Tungsten Alkylidene Complexes That Contain Sterically Demanding,4 we decided to explore some arylthiolate analogues of terphenoxide molybde- num imido and tungsten

  9. Tungsten silicide and tungsten polycide anisotropic dry etch process for highly controlled dimensions and profiles

    E-Print Network [OSTI]

    Bashir, Rashid

    dimensions and profiles R. Bashir,a),b) A. E. Kabir,b) F. Hebert,c) and C. Brackenb) National Semiconductors. In many applications a spacer needs to be formed on the polycide sidewall Fig. 1 . Undesirable undercutting can re- sult in nonideal spacer formation for further device fabrica- tion. Tungsten silicide

  10. Waste Heat Recovery – Submerged Arc Furnaces (SAF)

    E-Print Network [OSTI]

    O'Brien, T.

    2008-01-01T23:59:59.000Z

    Waste Heat Recovery- Submerged Arc Furnaces (SAF) Thomas O?Brien Recycled Energy Development, LLC tobrien@recycled-energy.com Submerged Arc Furnaces are used to produce high temperature alloys. These furnaces typically run at 3000oF using...

  11. TungsTen--2004 79. Referencesthatincludeasectionmark()arefoundintheInternet

    E-Print Network [OSTI]

    TungsTen--2004 79. Referencesthatincludeasectionmark(§)arefoundintheInternet ReferencesCitedsection. TungsTen ByKimB.shedd Domestic survey data and tables were prepared by Amy C. Tolcin, statistical assistant, and the world production table was prepared by Glenn J. Wallace, international data coordinator

  12. Kinetics of the decomposition of tungsten hexacarbonyl

    SciTech Connect (OSTI)

    Podoprigora, V.I.; Baev, A.K.

    1987-07-20T23:59:59.000Z

    A differential-flow apparatus is devised for the study of the kinetics of the thermal decomposition of volatile metal carbonyls under quasi-stationary conditions. The applicability of the general kinetic approach to the investigation of the thermodecomposition of carbonyl compounds and of the analysis of the experimental data on the basis of specific thermodecomposition rates was proved. Well-founded kinetic characteristics were obtained for the first time for the thermodecomposition of tungsten carbonyl in the kinetic region and under quasi-stationary pyrolysis conditions.

  13. Low temperature photoresponse of monolayer tungsten disulphide

    SciTech Connect (OSTI)

    Cao, Bingchen; Shen, Xiaonan; Shang, Jingzhi; Cong, Chunxiao; Yang, Weihuang; Eginligil, Mustafa, E-mail: yuting@ntu.edu.sg, E-mail: meginligil@ntu.edu.sg [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371 (Singapore); Yu, Ting, E-mail: yuting@ntu.edu.sg, E-mail: meginligil@ntu.edu.sg [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371 (Singapore); Department of Physics, Faculty of Science, National University of Singapore, Singapore, 117542 (Singapore); Graphene Research Centre, National University of Singapore, Singapore, 117546 (Singapore)

    2014-11-01T23:59:59.000Z

    High photoresponse can be achieved in monolayers of transition metal dichalcogenides. However, the response times are inconveniently limited by defects. Here, we report low temperature photoresponse of monolayer tungsten disulphide prepared by exfoliation and chemical vapour deposition (CVD) method. The exfoliated device exhibits n-type behaviour; while the CVD device exhibits intrinsic behaviour. In off state, the CVD device has four times larger ratio of photoresponse for laser on/off and photoresponse decay–rise times are 0.1 s (limited by our setup), while the exfoliated device has few seconds. These findings are discussed in terms of charge trapping and localization.

  14. Tungsten Mountain Geothermal Area | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin Baxin HydropowerTrinity Thermal Systems JumpTrueTullahomaTungsten

  15. Laboratory experiments on arc deflection and instability

    SciTech Connect (OSTI)

    Zweben, S.; Karasik, M.

    2000-03-21T23:59:59.000Z

    This article describes experiments on arc deflection instability carried out during the past few years at the Princeton University Plasma Physics Laboratory (PPPL). The approach has been that of plasma physicists interested in arcs, but they believe these results may be useful to engineers who are responsible for controlling arc behavior in large electric steel furnaces.

  16. Corrosion and wear resistance of tungsten carbide-cobalt and tungsten carbide-cobalt-chromium thermal spray coatings

    SciTech Connect (OSTI)

    Quets, J.; Alford, J.R.

    1999-07-01T23:59:59.000Z

    Tungsten carbide thermal spray coatings provide wear surfaces to new and overhauled components for various industries. Their wear resistance is obtained by incorporating small tungsten carbide particles into a metal matrix. This presentation will show what parameters influence their corrosion resistance in the ASTM B-117 Salt Spray Corrosion Test,

  17. Metal vapor arc ion plating

    DOE Patents [OSTI]

    Bertram, L.A.; Fisher, R.W.; Mattox, D.M.; Zanner, F.J.

    1986-09-09T23:59:59.000Z

    A method and apparatus for ion plating are described. The apparatus uses more negative than a first electrode voltage in a vacuum arc remelt system to attract low energy ions from the anode electrode to the article to be plated. 2 figs.

  18. Adsorption of carbonyl sulfide on nickel and tungsten films

    SciTech Connect (OSTI)

    Saleh, J.M.; Nasser, F.A.K.

    1985-07-18T23:59:59.000Z

    The interaction of carbonyl sulfide with evaporated nickel and tungsten films has been investigated in the temperature range 195-450 K using gas pressures ranging from 1 to 13 N m/sup -2/. Rapid but mainly associative chemisorption of COS occurred on both metals at 195 K. Further adsorption of COS on W at temperatures 293-450 K was extremely slow and accompanied by more CO desorption than COS adsorbed. Sulfidation of Ni film by COS occurred at temperatures greater than or equal to 293 K with the liberation of carbon monoxide. The rate of adsorption increased with temperature but was independent of COS pressure. The activation energy (E/sub x/) increased with extent (X) of sulfidation to a limiting value of 97 kJ mol/sup -1/. A linear relationship was obtained from the plot of E/sub x/ against 1/X, suggesting the applicability of Cabrera-Mott theory to the sulfidation of Ni film by COS. 20 references, 2 figures, 1 table.

  19. Tungsten Transport in JET H-mode Plasmas in Hybrid Scenario, Experimental Observations and Modelling

    E-Print Network [OSTI]

    Tungsten Transport in JET H-mode Plasmas in Hybrid Scenario, Experimental Observations and Modelling

  20. Author's personal copy Tungsten geochemistry and implications for understanding the Earth's interior

    E-Print Network [OSTI]

    Mcdonough, William F.

    Author's personal copy Tungsten geochemistry and implications for understanding the Earth Keywords: tungsten uranium basalt core mantle concentration ratio The concentration of tungsten (W of tungsten (W) was sequestered into the core (Jagoutz et al., 1979; Sun, 1982; Newsom and Palme, 1984

  1. Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

    E-Print Network [OSTI]

    Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

  2. TUNGSTEN--2003 79.1 References that include a section mark () are found in the Internet

    E-Print Network [OSTI]

    Stockpile (NDS) and increases in stocks held by U.S. industry. No U.S. tungsten mine production was reported reported in 2001. Salient U.S. tungsten statistics and world tungsten concentrate production for 2003TUNGSTEN--2003 79.1 1 References that include a section mark (§) are found in the Internet

  3. Reduced ternary molybdenum and tungsten sulfides and hydroprocessing catalysis therewith

    DOE Patents [OSTI]

    Hilsenbeck, S.J.; McCarley, R.E.; Schrader, G.L.; Xie, X.B.

    1999-02-16T23:59:59.000Z

    New amorphous molybdenum/tungsten sulfides with the general formula M{sup n+}{sub 2x/n}(L{sub 6}S{sub 8})S{sub x}, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M{sub 6}S{sub 8}){sup 0} cluster units are present. Vacuum thermolysis of the amorphous Na{sub 2x}(Mo{sub 6}S{sub 8})S{sub x}{hor_ellipsis}yMeOH first produces poorly crystalline NaMo{sub 6}S{sub 8} by disproportionation at 800 C and well-crystallized NaMo{sub 6}S{sub 8} at {>=} 900 C. Ion-exchange of the sodium material in methanol with soluble M{sup 2+} and M{sup 3+} salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M{sup n+}{sub 2x/n}(Mo{sub 6}S{sub 8})S{sub x}{hor_ellipsis}yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M{sup n+}{sub 2x/n}Mo{sub 6}S{sub 8+x}(MeOH){sub y}[MMOS] (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as ``Chevrel phase-like`` in that both contain Mo{sub 6}S{sub 8} cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst is shown to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS{sub 2} catalysts. 9 figs.

  4. Reduced ternary molybdenum and tungsten sulfides and hydroprocessing catalysis therewith

    DOE Patents [OSTI]

    Hilsenbeck, Shane J. (Ames, IA); McCarley, Robert E. (Ames, IA); Schrader, Glenn L. (Ames, IA); Xie, Xiaobing (College Station, TX)

    1999-02-16T23:59:59.000Z

    New amorphous molybdenum/tungsten sulfides with the general formula M.sup.n+.sub.2x/n (L.sub.6 S.sub.8)S.sub.x, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M.sub.6 S.sub.8).sup.0 cluster units are present. Vacuum thermolysis of the amorphous Na.sub.2x (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH first produces poorly crystalline NaMo.sub.6 S.sub.8 by disproportionation at 800.degree. C. and well-crystallized NaMo.sub.6 S.sub.8 at .gtoreq. 900.degree. C. Ion-exchange of the sodium material in methanol with soluble M.sup.2+ and M.sup.3+ salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M.sup.n+.sub.2x/n (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M.sup.n+.sub.2x/n Mo.sub.6 S.sub.8+x (MeOH).sub.y ›MMOS! (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as "Chevrel phase-like" in that both contain Mo.sub.6 S.sub.8 cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst showed to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS.sub.2 catalysts.

  5. Lightning Induced Arcing an LDRD Report

    SciTech Connect (OSTI)

    JORGENSON,ROY E.; WARNE,LARRY K.; KUNHARDT,ERICH E.

    2000-12-01T23:59:59.000Z

    The purpose of this research was to develop a science-based understanding of the early-time behavior of electric surface arcing in air at atmospheric pressure. As a first step towards accomplishing this, we used a kinetic approach to model an electron swarm as it evolved in a neutral gas under the influence of an applied electric field. A computer code was written in which pseudo-particles, each representing some number of electrons, were accelerated by an electric field. The electric field due to the charged particles was calculated efficiently using a tree algorithm. Collision of the electrons with the background gas led to the creation of new particles through the processes of ionization and photoionization. These processes were accounted for using measured cross-section data and Monte Carlo methods. A dielectric half-space was modeled by imaging the charges in its surface. Secondary electron emission from the surface, resulting in surface charging, was also calculated. Simulation results show the characteristics of a streamer in three dimensions. A numerical instability was encountered before the streamer matured to form branching.

  6. Preparation and electrocatalytic activity of tungsten carbide and titania nanocomposite

    SciTech Connect (OSTI)

    Hu, Sujuan; Shi, Binbin; Yao, Guoxing [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Li, Guohua, E-mail: nanozjut@zjut.edu.cn [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Ma, Chunan [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)

    2011-10-15T23:59:59.000Z

    Graphical abstract: The electrocatalytic activity of tungsten carbide and titania nanocomposite is related to the structure, crystal phase and chemical components of the nanocomposite, and is also affected by the property of electrolyte. A synergistic effect exists between tungsten carbide and titania of the composite. Highlights: {yields} Electrocatalytic activity of tungsten carbide and titania nanocomposite with core-shell structure. {yields} Activity is related to the structure, crystal phase and chemical component of the nanocomposite. {yields} The property of electrolyte affects the electrocatalytic activity. {yields} A synergistic effect exists between tungsten carbide and titania of the composite. -- Abstract: Tungsten carbide and titania nanocomposite was prepared by combining a reduced-carbonized approach with a mechanochemical approach. The samples were characterized by X-ray diffraction, transmission electron microscope under scanning mode and X-ray energy dispersion spectrum. The results show that the crystal phases of the samples are composed of anatase, rutile, nonstoichiometry titanium oxide, monotungsten carbide, bitungsten carbide and nonstoichiometry tungsten carbide, and they can be controlled by adjusting the parameters of the reduced-carbonized approach; tungsten carbide particles decorate on the surface of titania support, the diameter of tungsten carbide particle is smaller than 20 nm and that of titania is around 100 nm; the chemical components of the samples are Ti, O, W and C. The electrocatalytic activity of the samples was measured by a cyclic voltammetry with three electrodes. The results indicate that the electrocatalytic activities of the samples are related to their crystal phases and the property of electrolyte in aqueous solution. A synergistic effect between titania and tungsten carbide is reported for the first time.

  7. Filters for cathodic arc plasmas

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA); Bilek, Marcela M. M. (Engadine, AU); Brown, Ian G. (Berkeley, CA)

    2002-01-01T23:59:59.000Z

    Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  8. Tungsten-doped thin film materials

    DOE Patents [OSTI]

    Xiang, Xiao-Dong; Chang, Hauyee; Gao, Chen; Takeuchi, Ichiro; Schultz, Peter G.

    2003-12-09T23:59:59.000Z

    A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3, where X is between about 0.5 and about 1.0. Also provided is a method for making a dielectric thin film of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3 and doped with W, where X is between about 0.5 and about 1.0, a substrate is provided, TiO.sub.2, the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO.sub.2, the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

  9. Stability measurements of PPL atmospheric pressure arc

    SciTech Connect (OSTI)

    Roquemore, L.; Zweben, S.J. [Princeton Plasma Physics Lab., NJ (United States); Wurden, G.A. [Los Alamos National Lab., NM (United States)

    1997-12-31T23:59:59.000Z

    Experiments on the stability of atmospheric pressure arcs have been started at PPL to understand and improve the performance of arc furnaces used for processing applications in metallurgy and hazardous waste treatment. Previous studies have suggested that the violent instabilities in such arcs may be due to kink modes. A 30 kW, 500 Amp CW DC experimental arc furnace was constructed with a graphite cathode and a molten steel anode. The arc plasma is diagnosed with 4000 frames/sec digital camera, Hall probes, and voltage and current monitors. Under certain conditions, the arc exhibits an intermittent helical instability, with the helix rotating at {approx}600 Hz. The nature of the instability is investigated. A possible instability mechanism is the self-magnetic field of the arc, with saturation occurring due to inhomogeneous heating in a helical arc. The effect of external DC and AC magnetic fields on the instability is investigated. Additionally, arc deflection due to external transverse magnetic field is investigated. The deflection angle is found to be proportional to the applied field, and is in good agreement with a simple model of the {rvec J} x {rvec b} force on the arc jet.

  10. TUNGSTEN--1999 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , and/or contacts are used in lighting, electronic, electrical, heating, and welding applications and coatings. Chemical uses of tungsten include catalysts, inorganic pigments, and high-temperature lubricants

  11. TUNGSTEN--1998 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , and/or contacts are used in lighting, electronic, electrical, heating, and welding applications and coatings. Chemical uses of tungsten include catalysts, inorganic pigments, and high-temperature lubricants

  12. Atomistic computer simulation analysis of nanocrystalline nickel-tungsten alloys

    E-Print Network [OSTI]

    Engwall, Alison Michelle

    2009-01-01T23:59:59.000Z

    Nanocrystalline nickel-tungsten alloys are harder, stronger, more resistant to degradation, and safer to electrodeposit than chromium. Atomistic computer simulations have previously met with success in replicating the ...

  13. Microstructured tungsten thermophotovoltaic selective emitters c by Natalija (Zorana) Jovanovi?.

    E-Print Network [OSTI]

    Jovanovic, Natalija Zorana

    2008-01-01T23:59:59.000Z

    This research investigates the fabrication, modeling, characterization, and application of tungsten two-dimensional (2D) photonic crystal (PhC) structures as selective emitters and means of achieving higher efficiencies ...

  14. Alkyne metathesis by molybdenum and tungsten alkylidyne complexes

    E-Print Network [OSTI]

    Schrock, Richard Royce

    Alkyne metathesis by molybdenum and tungsten alkylidyne complexes is now ~45 years old. Progress in the practical aspects of alkyne metathesis reactions with well-defined complexes, as well as applications, in the last ...

  15. Tungsten carbide-cobalt by Three Dimensional Printing

    E-Print Network [OSTI]

    Kelley, Andrew, III

    1998-01-01T23:59:59.000Z

    Three Dimensional Printing is an additive manufacturing process for rapid prototyping ceramic and metallic parts [Sachs, et al, 1990]. Green (not sintered) tungsten carbide-cobalt parts must have a density greater than 50% ...

  16. Plasma arc torch with coaxial wire feed

    DOE Patents [OSTI]

    Hooper, Frederick M (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A plasma arc welding apparatus having a coaxial wire feed. The apparatus includes a plasma arc welding torch, a wire guide disposed coaxially inside of the plasma arc welding torch, and a hollow non-consumable electrode. The coaxial wire guide feeds non-electrified filler wire through the tip of the hollow non-consumable electrode during plasma arc welding. Non-electrified filler wires as small as 0.010 inches can be used. This invention allows precision control of the positioning and feeding of the filler wire during plasma arc welding. Since the non-electrified filler wire is fed coaxially through the center of the plasma arc torch's electrode and nozzle, the wire is automatically aimed at the optimum point in the weld zone. Therefore, there is no need for additional equipment to position and feed the filler wire from the side before or during welding.

  17. ARC-ED Curriculum: The Application of Video Game Formats to Educational Software

    E-Print Network [OSTI]

    Chaffin, Jerry D.; Maxwell, Bill; Thompson, Barbara

    1982-01-01T23:59:59.000Z

    educational practices are examined in relation to the motivational features of arcade games. Also, guidelines for educational curriculum based on arcade game formats are proposed and the term Arc-Ed Curriculum is offered to describe such software. The content...

  18. Surface Coating of Tungsten Carbide by Electric Exploding of Contact

    SciTech Connect (OSTI)

    Grigoryev, Evgeny G. [General Physics Department, Moscow Engineering Physics Institute, Kashirskoe sh. 31, Moscow, 115409 (Russian Federation)

    2011-01-17T23:59:59.000Z

    Electric exploding of a tungsten carbide--cobalt material near-by high-speed steel surface forms on it a hardening coating. The essential structure properties of the formed coatings are determined by parameters of contact exploding electrode at the pulse current amplitude from above 106 A/cm2 and duration less than 10-4 s. The metallographic investigations of coating structures were done by microscope 'Neophot-24'. They have shown that the contact electric exploding caused the transfer of tungsten carbide and cobalt on the surface of high-speed steel. The breakdown of tungsten carbide--cobalt material took place during electrical exploding. The hardening layers of tungsten carbide and pure nanocrystalline tungsten have been formed upon the surface of high-speed steel as a result of electric exploding. Crystalline grains of tungsten have an almost spherical form and their characteristic size less than 400 nanometers. Micro hardness of the coating layers and high-speed steel structures was measured.

  19. Linkage of the ArcHydro Data Model with SWAT

    E-Print Network [OSTI]

    Linkage of the ArcHydro Data Model with SWAT Francisco Olivera, Ph.D., P.E. Milver Valenzuela Texas on a hub basis. Independent of the already connected models HUB #12;Arc Hydro Arc Hydro can be used as the hub for connecting hydrologic models. #12;Arc Hydro #12;What it is and what it is not ... Arc Hydro

  20. Groundwater Modeling in ArcView: by integrating ArcView, MODFLOW and

    E-Print Network [OSTI]

    Sengupta, Raja

    Groundwater Modeling in ArcView: by integrating ArcView, MODFLOW and MODPATH Abstract Modeling. This paper addresses groundwater modeling which is one of the many entities in environmental modeling in ArcView 3.2a. The objective was to create an integrated system where a user could do groundwater

  1. Miniaturized cathodic arc plasma source

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA)

    2003-04-15T23:59:59.000Z

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  2. T-1018 UCLA Spacordion Tungsten Powder Calorimeter

    SciTech Connect (OSTI)

    Trentalange, Stephen; Tsai, Oleg; Igo, George; Huang, Huan; Pan, Yu Xi; Dunkelberger, Jay; Xu, Wen Qin; /UCLA; Soha, Aria; /Fermilab; Heppelmann, Steven; /Penn State U.; Gagliardi, Carl; /Texas A-M

    2011-11-16T23:59:59.000Z

    The present experiments at the BNL-RHIC facility are evolving towards physics goals which require the detection of medium energy electromagnetic particles (photons, electrons, neutral pions, eta mesons, etc.), especially at forward angles. New detectors will place increasing demands on energy resolution, hadron rejection and two-photon resolution and will require large area, high performance electromagnetic calorimeters in a variety of geometries. In the immediate future, either RHIC or JLAB will propose a facility upgrade (Electron-Ion Collider, or EIC) with physics goals such as electron-heavy ion collisions (or p-A collisions) with a wide range of calorimeter requirements. An R and D program based at Brookhaven National Laboratory has awarded the group funding of approximately $110,000 to develop new types of calorimeters for EIC experiments. The UCLA group is developing a method to manufacture very flexible and cost-effective, yet high quality calorimeters based on scintillating fibers and tungsten powder. The design and features of the calorimeter can be briefly stated as follows: an arbitrarily large number of small diameter fibers (< 0.5 mm) are assembled as a matrix and held rigidly in place by a set of precision screens inside an empty container. The container is then back-filled with tungsten powder, compacted on a vibrating table and infused with epoxy under vacuum. The container is then removed. The resulting sub-modules are extremely uniform and achieve roughly the density of pure Lead. The sub-modules are stacked together to achieve a final detector of the desired shape. There is no dead space between sub-modules and the fibers can be in an accordion geometry bent to prevent 'channeling' of the particles due to accidental alignment of their track with the module axis. This technology has the advantage of being modular and inexpensive to the point where the construction work may be divided among groups the size of typical university physics departments. This test run if a proof-of-principle and allows the experiment to improve the design and performance of the final detectors. The experimenters have constructed prototypes of three different designs in order to investigate the characteristics of practical devices such as uniformity, linearity, longitudinal and transverse shower shapes. The first design is an array of 4 x 4 modules intended as a prototype for a practical device to be installed within two years in the STAR experimental hall. The modules are a combination of a spaghetti calorimeter and an accordion (hence 'spacordion'). Each sub-module is 1.44 cm x 1.44 cm x 15 cm and constructed individually. The second design is a prototype of 4 sub-modules constructed in one step, using a different construction technique. The third design is a set of single sub-modules each intended to test variations of the tungsten powder/embedded fiber concept by enhancing the light output/density using liquid scintillator or heavy liquids.

  3. Plasma arc melting of zirconium

    SciTech Connect (OSTI)

    Tubesing, P.K.; Korzekwa, D.R.; Dunn, P.S.

    1997-12-31T23:59:59.000Z

    Zirconium, like some other refractory metals, has an undesirable sensitivity to interstitials such as oxygen. Traditionally, zirconium is processed by electron beam melting to maintain minimum interstitial contamination. Electron beam melted zirconium, however, does not respond positively to mechanical processing due to its large grain size. The authors undertook a study to determine if plasma arc melting (PAM) technology could be utilized to maintain low interstitial concentrations and improve the response of zirconium to subsequent mechanical processing. The PAM process enabled them to control and maintain low interstitial levels of oxygen and carbon, produce a more favorable grain structure, and with supplementary off-gassing, improve the response to mechanical forming.

  4. Plasma arc melting of titanium-tantalum alloys

    SciTech Connect (OSTI)

    Dunn, P.; Patterson, R.A. [Los Alamos National Lab., NM (United States); Haun, R. [Retech, Inc., Ukiah, CA (United States)

    1994-08-01T23:59:59.000Z

    Los Alamos has several applications for high temperature, oxidation and liquid-metal corrosion resistant materials. Further, materials property constraints are dictated by a requirement to maintain low density; e.g., less than the density of stainless steel. Liquid metal compatibility and density requirements have driven the research toward the Ti-Ta system with an upper bound of 60 wt% Ta-40 wt% Ti. Initial melting of these materials was performed in a small button arc melter with several hundred grams of material; however, ingot quantities were soon needed. But, refractory metal alloys whose constituents possess very dissimilar densities, melting temperatures and vapor pressures pose significant difficulty and require specialized melting practices. The Ti-Ta alloys fall into this category with the density of tantalum 16.5 g/cc and that of titanium 4.5 g/cc. Melting is further complicated by the high melting point of Ta(3020 C) and the relatively low boiling point of Ti(3287 C). Previous electron beam melting experience with these materials resulted, in extensive vaporization of the titanium and poor chemical homogeneity. Vacuum arc remelting(VAR) was considered as a melting candidate and discarded due to density and vapor pressure issues associated with electron beam. Plasma arc melting offered the ability to supply a cover gas to deal with vapor pressure issues as well as solidification control to help with macrosegregation in the melt and has successfully produced high quality ingots of the Ti-Ta alloys.

  5. Comparative Analysis of Carbon Plasma in Arc and RF Reactors

    SciTech Connect (OSTI)

    Todorovic-Markovic, B.; Markovic, Z. ['Vinca' Institute of Nuclear Sciences, P.O.B. 522, 11001 Belgrade (Serbia and Montenegro); Mohai, I.; Szepvolgyi, J. [Research Laboratory of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences H-1525 Budapest, POB 17 (Hungary)

    2004-12-01T23:59:59.000Z

    Results on studies of molecular spectra emitted in the initial stages of fullerene formation during the processing of graphite powder in induction RF reactor and evaporation of graphite electrodes in arc reactor are presented in this paper. It was found that C2 radicals were dominant molecular species in both plasmas. C2 radicals have an important role in the process of fullerene synthesis. The rotational-vibrational temperatures of C2 and CN species were calculated by fitting the experimental spectra to the simulated ones. The results of optical emission study of C2 radicals generated in carbon arc plasma have shown that rotational temperature of C2 species depends on carbon concentration and current intensity significantly. The optical emission study of induction RF plasma and SEM analysis of graphite powder before and after plasma treatment have shown that evaporation of the processed graphite powder depends on feed rate and composition of gas phase significantly. Based on the obtained results, it was concluded that in the plasma region CN radicals could be formed by the reaction of C2 species with atomic nitrogen at smaller loads. At larger feed rate of graphite powder, CN species were produced by surface reaction of the hot carbon particles with nitrogen atoms. The presence of nitrogen in induction RF plasma reduces the fullerene yield significantly. The fullerene yield obtained in two different reactors was: 13% in arc reactor and 4.1% in induction RF reactor. However, the fullerene production rate was higher in induction RF reactor-6.4 g/h versus 1.7 g/h in arc reactor.

  6. Nitrogen Control in Electric Arc Furnace Steelmaking by Direct...

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

    Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines...

  7. antilles island arc: Topics by E-print Network

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

    The morphology of the underthrust oceanic crust controls the mag matic activity of the island arc, and particularly the development, in space and time, of "arc compartments." Denis...

  8. Type B Accident Investigation of the Arc Flash at Brookhaven...

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

    Arc Flash at Brookhaven National Laboratory, April 14, 2006 Type B Accident Investigation of the Arc Flash at Brookhaven National Laboratory, April 14, 2006 February 10, 2006 An...

  9. PHYSICAL REVIEW B 84, 092102 (2011) Melting temperature of tungsten from two ab initio approaches

    E-Print Network [OSTI]

    Alfè, Dario

    2011-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 84, 092102 (2011) Melting temperature of tungsten from two ab initio approaches L the melting temperature of tungsten by two ab initio approaches. The first approach can be divided into two

  10. Structure-property Relationships in Pure and Doped Epitaxial Tungsten Trioxide Thin Films

    E-Print Network [OSTI]

    Structure-property Relationships in Pure and Doped Epitaxial Tungsten Trioxide Thin Films Principal-property relationships of well- defined epitaxial tungsten trioxide (WO3) films with and without dopants, and thereby

  11. Olefin Metathesis Reactions Initiated by d2 Molybdenum or Tungsten Complexes

    E-Print Network [OSTI]

    Müller, Peter

    Olefin Metathesis Reactions Initiated by d2 Molybdenum or Tungsten Complexes Richard R. Schrock species, behave as olefin metathesis catalysts. Recently we reported tungsten complexes that contain a Wd

  12. Room-Temperature Z-Selective Homocoupling of alpha-Olefins by Tungsten Catalysts

    E-Print Network [OSTI]

    Marinescu, Smaranda C.

    3,5-Dimethylphenylimido complexes of tungsten can be prepared using procedures analogous to those employed for other tungsten catalysts, as can bispyrrolide species and MonoAryloxide-Pyrrolide (MAP) species. Homocouplings ...

  13. Theoretical analysis of ARC constriction

    SciTech Connect (OSTI)

    Stoenescu, M.L.; Brooks, A.W.; Smith, T.M.

    1980-12-01T23:59:59.000Z

    The physics of the thermionic converter is governed by strong electrode-plasma interactions (emissions surface scattering, charge exchange) and weak interactions (diffusion, radiation) at the maximum interelectrode plasma radius. The physical processes are thus mostly convective in thin sheaths in front of the electrodes and mostly diffusive and radiative in the plasma bulk. The physical boundaries are open boundaries to particle transfer (electrons emitted or absorbed by the electrodes, all particles diffusing through some maximum plasma radius) and to convective, conductive and radiative heat transfer. In a first approximation the thermionic converter may be described by a one-dimensional classical transport theory. The two-dimensional effects may be significant as a result of the sheath sensitivity to radial plasma variations and of the strong sheath-plasma coupling. The current-voltage characteristic of the converter is thus the result of an integrated current density over the collector area for which the boundary conditions at each r determine the regime (ignited/unignited) of the local current density. A current redistribution strongly weighted at small radii (arc constriction) limits the converter performance and opens questions on constriction reduction possibilities. The questions addressed are the followng: (1) what are the main contributors to the loss of current at high voltage in the thermionic converter; and (2) is arc constriction observable theoretically and what are the conditions of its occurrence. The resulting theoretical problem is formulated and results are given. The converter electrical current is estimated directly from the electron and ion particle fluxes based on the spatial distribution of the electron/ion density n, temperatures T/sub e/, T/sub i/, electrical voltage V and on the knowledge of the transport coefficients. (WHK)

  14. A history of tungsten- and molybdenum-base alloys

    SciTech Connect (OSTI)

    Heestand, R.L.

    1993-01-01T23:59:59.000Z

    The development of tungsten and molybdenum alloys was initiated in the early 1900s in search of a better electric lamp filament with tantalum, tungsten, rhenium, and osmium being the prime candidates. The efforts required for accomplishment of the task led to refining oxides to high purity, reduction of the oxides to metal powders, forming green product forms by extrusion or pressing, and finally sintering by electric furnace and self-heating by direct current almost to the melting point. The technology required for producing lamp filaments led to the development of the powder metallurgy field and early research on high-melting-temperature metals. During the period 1909 through 1959, most of the tungsten-molybdenum, high-melting-temperature element alloys were developed and produced in almost any product form required.

  15. A history of tungsten- and molybdenum-base alloys

    SciTech Connect (OSTI)

    Heestand, R.L.

    1993-05-01T23:59:59.000Z

    The development of tungsten and molybdenum alloys was initiated in the early 1900s in search of a better electric lamp filament with tantalum, tungsten, rhenium, and osmium being the prime candidates. The efforts required for accomplishment of the task led to refining oxides to high purity, reduction of the oxides to metal powders, forming green product forms by extrusion or pressing, and finally sintering by electric furnace and self-heating by direct current almost to the melting point. The technology required for producing lamp filaments led to the development of the powder metallurgy field and early research on high-melting-temperature metals. During the period 1909 through 1959, most of the tungsten-molybdenum, high-melting-temperature element alloys were developed and produced in almost any product form required.

  16. Mechanism of vacancy formation induced by hydrogen in tungsten

    SciTech Connect (OSTI)

    Liu, Yi-Nan [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China) [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China); Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland); Ahlgren, T.; Bukonte, L.; Nordlund, K. [Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland)] [Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland); Shu, Xiaolin; Yu, Yi; Lu, Guang-Hong, E-mail: LGH@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China)] [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China); Li, Xiao-Chun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)] [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)

    2013-12-15T23:59:59.000Z

    We report a hydrogen induced vacancy formation mechanism in tungsten based on classical molecular dynamics simulations. We demonstrate the vacancy formation in tungsten due to the presence of hydrogen associated directly with a stable hexagonal self-interstitial cluster as well as a linear crowdion. The stability of different self-interstitial structures has been further studied and it is particularly shown that hydrogen plays a crucial role in determining the configuration of SIAs, in which the hexagonal cluster structure is preferred. Energetic analysis has been carried out to prove that the formation of SIA clusters facilitates the formation of vacancies. Such a mechanism contributes to the understanding of the early stage of the hydrogen blistering in tungsten under a fusion reactor environment.

  17. Ductile tungsten-nickel alloy and method for making same

    DOE Patents [OSTI]

    Snyder, Jr., William B. (Knoxville, TN)

    1976-01-01T23:59:59.000Z

    The present invention is directed to a ductile, high-density tungsten-nickel alloy which possesses a tensile strength in the range of 100,000 to 140,000 psi and a tensile elongation of 3.1 to 16.5 percent in 1 inch at 25.degree.C. This alloy is prepared by the steps of liquid phase sintering a mixture of tungsten-0.5 to 10.0 weight percent nickel, heat treating the alloy at a temperature above the ordering temperature of approximately 970.degree.C. to stabilize the matrix phase, and thereafter rapidly quenching the alloy in a suitable liquid to maintain the matrix phase in a metastable, face-centered cubic, solid- solution of tungsten in nickel.

  18. Tungsten as first wall material in the main chamber of ASDEX Upgrade

    E-Print Network [OSTI]

    Tungsten as first wall material in the main chamber of ASDEX Upgrade V. Rohde, R. Neu, A. Geier, R material is tungsten, which has a high melting point, low erosion rate in cold scrape off layer plasma, where the present ITER-FEAT design uses tungsten. No negative influence on the plasma performance, even

  19. DOI: 10.1002/adsc.201100200 Preparation of Tungsten-Based Olefin Metathesis Catalysts

    E-Print Network [OSTI]

    Müller, Peter

    DOI: 10.1002/adsc.201100200 Preparation of Tungsten-Based Olefin Metathesis Catalysts Supported://dx.doi.org/10.1002/adcs.201100200. Abstract: A new tungsten alkylidene complex, WACHTUNGTRENNUNG catalysts; tungsten Introduction In the last dozen years various "well-defined" Mo/W[1] or Ru[2] olefin

  20. ORIGINAL PAPER Why is the molybdenum-substituted tungsten-dependent

    E-Print Network [OSTI]

    Liao, Rongzhen

    ORIGINAL PAPER Why is the molybdenum-substituted tungsten-dependent formaldehyde ferredoxin oxidoreductase is a tungsten-dependent enzyme that catalyzes the oxidative degradation of formaldehyde to formic acid. The moly- bdenum ion can be incorporated into the active site to displace the tungsten ion

  1. Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Chloride As the Acid

    E-Print Network [OSTI]

    Müller, Peter

    Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Supporting Information ABSTRACT: Routes to new tungsten alkylidene complexes that contain tert and tungsten, especially aryls that are mono- or disubstituted in the ortho position(s).2 However, it has

  2. Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement Regime

    E-Print Network [OSTI]

    Osterloh, Frank

    Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement, catalysis, WO3, tungsten oxide, nanosheet, nanocrystal, quantum confinement, solar energy conversion INTRODUCTION Tungsten trioxide crystallizes in the ReO3 structure type and is an n-type semiconductor with a 2

  3. Synthesis and Reactions of Tungsten Alkylidene Complexes That Contain the 2,6-Dichlorophenylimido Ligand

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis and Reactions of Tungsten Alkylidene Complexes That Contain the 2,6-Dichlorophenylimido Institute of Technology, Cambridge, Massachusetts 02139 ReceiVed October 30, 2006 Tungsten alkylidene alkylidene bisalkoxide complexes of molybdenum or tungsten of the type M(NR)(CHR)(OR)2 are now established

  4. Imido Alkylidene Bispyrrolyl Complexes of Tungsten Thorsten Kreickmann, Stefan Arndt, Richard R. Schrock,* and Peter Muller

    E-Print Network [OSTI]

    Müller, Peter

    Imido Alkylidene Bispyrrolyl Complexes of Tungsten Thorsten Kreickmann, Stefan Arndt, Richard R, Massachusetts 02139 ReceiVed July 16, 2007 We have prepared tungsten bispyrrolyl (Pyr) or bis-2 this type of chemistry to tungsten. In this paper we report W(NR)(CHCMe2R)(pyrrolyl)2 complexes where R is 2

  5. Nanostructured tungsten carbide catalysts for polymer electrolyte fuel cells X. G. Yanga

    E-Print Network [OSTI]

    Nanostructured tungsten carbide catalysts for polymer electrolyte fuel cells X. G. Yanga and C. Y/air polymer electrolyte fuel cell using nanoscale tungsten carbide as the anode catalyst and carbon supported, thereby creating a fundamental technology to reduce the cost of future fuel cell engines. The tungsten

  6. Radial x-ray diffraction of tungsten tetraboride to 86 GPa under nonhydrostatic compression

    E-Print Network [OSTI]

    Lin, Jung-Fu "Afu"

    Radial x-ray diffraction of tungsten tetraboride to 86 GPa under nonhydrostatic compression Lun December 2012; published online 16 January 2013) Investigations of the equation of state of tungsten moduli and hardness exceed- ing or closing that of diamond. Tungsten tetraboride (WB4) is a candidate

  7. Z-Selective Olefin Metathesis Reactions Promoted by Tungsten Oxo Alkylidene Complexes

    E-Print Network [OSTI]

    Müller, Peter

    Z-Selective Olefin Metathesis Reactions Promoted by Tungsten Oxo Alkylidene Complexes Dmitry V). Early in the development of olefin metathesis catalysts that contain tungsten, it was shown that metathetically more active and reproducible systems were produced when tungsten oxo complexes were deliberately

  8. Compressibility and strength of nanocrystalline tungsten boride under compression to 60GPa

    E-Print Network [OSTI]

    Duffy, Thomas S.

    Compressibility and strength of nanocrystalline tungsten boride under compression to 60GPa Haini://jap.aip.org/about/rights_and_permissions #12;Compressibility and strength of nanocrystalline tungsten boride under compression to 60 GPa Haini of nanocrystalline tungsten boride (WB) were investigated using radial x-ray diffraction (RXRD) in a diamond

  9. Synthesis of Tungsten Imido Alkylidene Complexes that Contain an Electron-Withdrawing Imido Ligand

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis of Tungsten Imido Alkylidene Complexes that Contain an Electron-Withdrawing Imido Ligand 02467, United States *S Supporting Information ABSTRACT: Tungsten NArR alkylidene complexes have been is the nature of Z. Perhaps the most dramatic variations are those in which M is tungsten and Z is an oxo ligand

  10. Mechanism of tungsten-dependent acetylene hydratase from quantum chemical calculations

    E-Print Network [OSTI]

    Liao, Rongzhen

    Mechanism of tungsten-dependent acetylene hydratase from quantum chemical calculations Rong hydratase is a tungsten-dependent enzyme that cata- lyzes the nonredox hydration of acetylene metalloenzyme cluster approach Tungsten is the heaviest metal in biology and plays prominent roles in carbon

  11. Real-time growth rate metrology for a tungsten chemical vapor deposition process by acoustic sensing

    E-Print Network [OSTI]

    Rubloff, Gary W.

    to a production-scale tungsten chemical vapor deposition cluster tool for in situ process sensing. Process gasesReal-time growth rate metrology for a tungsten chemical vapor deposition process by acoustic to achieve run-to-run process control of the deposited tungsten film thickness. © 2001 American Vacuum

  12. The Corrosion of Tungsten During Irradiation in an 800 MeV Proton Beam

    E-Print Network [OSTI]

    such technology is Accelerator Production of Tritium (APT). In APT a tungsten target is bombarded by a high energyThe Corrosion of Tungsten During Irradiation in an 800 MeV Proton Beam R. Scott Lillard, Darryl P of solid neutron spallation targets such as tungsten (W), and target cladding or structural materials

  13. Material Mixing of Tungsten with Carbon and Helium

    SciTech Connect (OSTI)

    Ueda, Y.; Lee, H. T. [Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan)

    2010-05-20T23:59:59.000Z

    In ITER, graphite and tungsten are used for divertor materials and are mixed through erosion, transport, and redeposition. Helium, a fusion reactant, is an intrinsic element in fusion plasmas that impinges on the metallic wall materials to form He bubbles. W-C mixed layers and He bubble layers greatly affect tritium retention. In this paper, impacts of W-C material mixing on erosion and hydrogen isotope retention are reviewed. Then, recent results on carbon deposition on tungsten in TEXTOR tokamak and helium effects on blistering and retention are discussed.

  14. Production And Characterization Of Tungsten-Based Positron Moderators

    SciTech Connect (OSTI)

    Lucio, O. G. de; Morales, J. G.; Cruz-Manjarrez, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364 01000, Mexico DF (Mexico)

    2011-06-01T23:59:59.000Z

    Experiments of interest in Atomic Physics require production of well-defined low-energy positron beams through a moderation process of high-energy positrons, which can be produced by either the use of a radioactive source or by accelerator based pair production process. Tungsten is one of the most commonly used moderator materials because of its reasonable efficiency, high work function and relatively low cost. In this work we present different methods to produce tungsten-based candidate moderators in a variety of shapes. We also present results from characterizing these candidate moderators by ion beam analysis and microscopy techniques.

  15. Effects of sequential tungsten and helium ion implantation on nano-indentation hardness of tungsten

    SciTech Connect (OSTI)

    Armstrong, D. E. J.; Edmondson, P. D.; Roberts, S. G. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)] [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

    2013-06-24T23:59:59.000Z

    To simulate neutron and helium damage in a fusion reactor first wall sequential self-ion implantation up to 13 dpa followed by helium-ion implantation up to 3000 appm was performed to produce damaged layers of {approx}2 {mu}m depth in pure tungsten. The hardness of these layers was measured using nanoindentation and was studied using transmission electron microscopy. Substantial hardness increases were seen in helium implanted regions, with smaller hardness increases in regions which had already been self-ion implanted, thus, containing pre-existing dislocation loops. This suggests that, for the same helium content, helium trapped in distributed vacancies gives stronger hardening than helium trapped in vacancies condensed into dislocation loops.

  16. Study on a negative hydrogen ion source with hot cathode arc discharge

    SciTech Connect (OSTI)

    Lin, S. H., E-mail: linshh@impcas.ac.cn; Fang, X. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China) [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Zhang, H. J.; Qian, C.; Ma, B. H.; Wang, H.; Li, X. X.; Zhang, X. Z.; Sun, L. T.; Zhang, Z. M.; Yuan, P.; Zhao, H. W. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China)] [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-02-15T23:59:59.000Z

    A negative hydrogen (H{sup ?}) ion source with hot cathode arc discharge was designed and fabricated as a primary injector for a 10 MeV PET cyclotron at IMP. 1 mA dc H{sup ?} beam with ? {sub N,} {sub RMS} = 0.08 ??mm?mrad was extracted at 25 kV. Halbach hexapole was adopted to confine the plasma. The state of arc discharge, the parameters including filament current, arc current, gas pressure, plasma electrode bias, and the ratio of I{sub e{sup ?}}/I{sub H{sup ?}} were experimentally studied. The discussion on the result, and opinions to improve the source were given.

  17. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2006,

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2006, approximately. Import Sources (2002-05): Tungsten contained in ores and concentrates, intermediate and primary products

  18. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2003,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2003, approximately and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 49

  19. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2005,

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2005, approximately. Import Sources (2001-04): Tungsten contained in ores and concentrates, intermediate and primary products

  20. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded U.S. production of tungsten concentrates was in 1994. In 2001,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded U.S. production of tungsten concentrates was in 1994. In 2001, approximately, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 41%; Russia, 21

  1. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2002,

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2002, approximately, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 48%; Russia, 16

  2. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2004,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2004, approximately (2000-03): Tungsten content of ores and concentrates, intermediate and primary products, wrought

  3. On the mechanism of operation of a cathode spot cell in a vacuum arc

    SciTech Connect (OSTI)

    Mesyats, G. A.; Petrov, A. A. [P. N. Lebedev Physical Institute, RAS, 53 Leninsky Ave., Moscow 119991 (Russian Federation); Bochkarev, M. B. [Institute of Electrophysics, UB, RAS, 106 Amundsen St., Ekaterinburg 620016 (Russian Federation); Barengolts, S. A., E-mail: sb@nsc.gpi.ru [A. M. Prokhorov General Physics Institute, RAS, 38 Vavilov St., Moscow 119991 (Russian Federation)

    2014-05-05T23:59:59.000Z

    The erosive structures formed on a tungsten cathode as a result of the motion of the cathode spot of a vacuum arc over the cathode surface have been examined. It has been found that the average mass of a cathode microprotrusion having the shape of a solidified jet is approximately equal to the mass of ions removed from the cathode within the lifetime of a cathode spot cell carrying a current of several amperes. The time of formation of a new liquid-metal jet under the action of the reactive force of the plasma ejected by the cathode spot is about 10?ns, which is comparable to the lifetime of a cell. The growth rate of a liquid-metal jet is ?10{sup 4}?cm/s. The geometric shape and size of a solidified jet are such that a new explosive emission center (spot cell) can be initiated within several nanoseconds during the interaction of the jet with the dense cathode plasma. This is the underlying mechanism of the self-sustained operation of a vacuum arc.

  4. Arc distribution during the vacuum arc remelting of Ti-6Al-4V

    SciTech Connect (OSTI)

    Woodside, Charles Rigel [U.S. DOE; King, Paul E. [U.S. DOE; Nordlund, Chris [ATI Albany Operations

    2013-01-01T23:59:59.000Z

    Currently, the temporal distribution of electric arcs across the ingot during vacuum arc remelting (VAR) is not a known or monitored process parameter. Previous studies indicate that the distribution of arcs can be neither diffuse nor axisymmetric about the center of the furnace. Correct accounting for the heat flux, electric current flux, and mass flux into the ingot is critical to achieving realistic solidification models of the VAR process. The National Energy Technology Laboratory has developed an arc position measurement system capable of locating arcs and determining the arc distribution within an industrial VAR furnace. The system is based on noninvasive magnetic field measurements and a VAR specific form of the Biot–Savart law. The system was installed on a coaxial industrial VAR furnace at ATI Albany Operations in Albany, OR. This article reports on the different arc distributions observed during production of Ti-6Al-4V. It is shown that several characteristic arc distribution modes can develop. This behavior is not apparent in the existing signals used to control the furnace, indicating the measurement system is providing new information. It is also shown that the different arc distribution modes observed may impact local solidification times, particularly at the side wall.

  5. Detection of arcs in automotive electrical systems

    E-Print Network [OSTI]

    Mishrikey, Matthew David

    2005-01-01T23:59:59.000Z

    At the present time, there is no established method for the detection of DC electric arcing. This is a concern for forthcoming advanced automotive electrical systems which consist of higher DC electric power bus voltages, ...

  6. ZrN coatings deposited by high power impulse magnetron sputtering and cathodic arc techniques

    SciTech Connect (OSTI)

    Purandare, Yashodhan, E-mail: Y.Purandare@shu.ac.uk; Ehiasarian, Arutiun; Hovsepian, Papken [Nanotechnology Centre for PVD Research, Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom); Santana, Antonio [Ionbond AG Olten, Industriestrasse 211, CH-4600 Olten (Switzerland)

    2014-05-15T23:59:59.000Z

    Zirconium nitride (ZrN) coatings were deposited on 1??m finish high speed steel and 316L stainless steel test coupons. Cathodic Arc (CA) and High Power Impulse Magnetron Sputtering (HIPIMS) + Unbalanced Magnetron Sputtering (UBM) techniques were utilized to deposit coatings. CA plasmas are known to be rich in metal and gas ions of the depositing species as well as macroparticles (droplets) emitted from the arc sports. Combining HIPIMS technique with UBM in the same deposition process facilitated increased ion bombardment on the depositing species during coating growth maintaining high deposition rate. Prior to coating deposition, substrates were pretreated with Zr{sup +} rich plasma, for both arc deposited and HIPIMS deposited coatings, which led to a very high scratch adhesion value (L{sub C2}) of 100 N. Characterization results revealed the overall thickness of the coatings in the range of 2.5??m with hardness in the range of 30–40?GPa depending on the deposition technique. Cross-sectional transmission electron microscopy and tribological experiments such as dry sliding wear tests and corrosion studies have been utilized to study the effects of ion bombardment on the structure and properties of these coatings. In all the cases, HIPIMS assisted UBM deposited coating fared equal or better than the arc deposited coatings, the reasons being discussed in this paper. Thus H+U coatings provide a good alternative to arc deposited where smooth, dense coatings are required and macrodroplets cannot be tolerated.

  7. The arc cloud complex: a case study

    E-Print Network [OSTI]

    Miller, Robert Loren

    1984-01-01T23:59:59.000Z

    THE ARC CLOUD COMPLEX: A CASE STUDY A Thesis by ROBERT LOREN MILLER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1984 Major Subject...: Meteorology THE ARC CLOUD COMPLEX; A CASE STUDY A Thesis by ROBERT LOREN MILLER Approved as to style and content by: Kenneth C. Brundidge (Chairman of Committee) Walter K. Henry (Member) Marshall ~ Mcparland (Member) James R. Scog s (Head...

  8. Tungsten and tungsten alloy powder metallurgy: Powder production and applications excluding lamps. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    Not Available

    1994-04-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning the preparation of metallic and ceramic powders of tungsten and tungsten alloys, including applications of these materials. The hydrogen reduction of tungsten compounds together with alloying element compounds produce forms with characteristics of high density, hardness, wear resistance, high melting points, and abrasiveness. Topics include production of cathodes, heaters, filament wires, electrical contacts, acoustic absorbers, high-density sheets and coatings, hard penetrators, and tungsten carbide and metallized ceramics. (Contains a minimum of 109 citations and includes a subject term index and title list.)

  9. Retention of Hydrogen Isotopes in Neutron Irradiated Tungsten

    SciTech Connect (OSTI)

    Yuji Hatano; Masashi Shimada; Yasuhisa Oya; Guoping Cao; Makoto Kobayashi; Masanori Hara; Brad J. Merrill; Kenji Okuno; Mikhail A. Sokolov; Yutai Katoh

    2013-03-01T23:59:59.000Z

    To investigate the effects of neutron irradiation on hydrogen isotope retention in tungsten, disk-type specimens of pure tungsten were irradiated in the High Flux Isotope Reactor in Oak Ridge National Laboratory followed by exposure to high flux deuterium (D) plasma in Idaho National Laboratory. The results obtained for low dose n-irradiated specimens (0.025 dpa for tungsten) are reviewed in this paper. Irradiation at coolant temperature of the reactor (around 50 degrees C) resulted in the formation of strong trapping sites for D atoms. The concentrations of D in n-irradiated specimens were ranging from 0.1 to 0.4 mol% after exposure to D plasma at 200 and 500 degrees C and significantly higher than those in non-irradiated specimens because of D-trapping by radiation defects. Deep penetration of D up to a depth of 50-100 µm was observed at 500 degrees C. Release of D in subsequent thermal desorption measurements continued up to 900 degrees C. These results were compared with the behaviour of D in ion-irradiated tungsten, and distinctive features of n-irradiation were discussed.

  10. Tungsten-yttria carbide coating for conveying copper

    DOE Patents [OSTI]

    Rothman, Albert J. (Livermore, CA)

    1993-01-01T23:59:59.000Z

    A method is provided for providing a carbided-tungsten-yttria coating on the interior surface of a copper vapor laser. The surface serves as a wick for the condensation of liquid copper to return the condensate to the interior of the laser for revolatilization.

  11. Author's personal copy Tungsten in Hawaiian picrites: A compositional model

    E-Print Network [OSTI]

    Mcdonough, William F.

    form 15 April 2009; available online 3 May 2009 Abstract Concentrations of tungsten (W) and uranium (U is three-times as enriched as the Depleted MORB Mantle (DMM; 3.0 ± 2.3 ng/g). The relatively high of the recycling of W-rich oceanic crust and sediment into a depleted mantle source, such as the depleted MORB

  12. Development of Bulk Nanocrystalline Cemented Tungsten Carbide for Industrial Applicaitons

    SciTech Connect (OSTI)

    Z. Zak Fang, H. Y. Sohn

    2009-03-10T23:59:59.000Z

    This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.

  13. Ion source with improved primary arc collimation

    DOE Patents [OSTI]

    Dagenhart, William K. (Oak Ridge, TN)

    1985-01-01T23:59:59.000Z

    An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power, thereby preventing the exposure of the anode to the full arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

  14. ABSTRACT. Keyhole plasma arc welding is a unique arc welding process for deep

    E-Print Network [OSTI]

    Zhang, YuMing

    ABSTRACT. Keyhole plasma arc welding is a unique arc welding process for deep penetration. To ensure the quality of the welds, the presence of the keyhole is crit- ical. Understanding of the keyhole will certainly benefit the improvement of the process and weld quality. Currently, the size of the keyhole

  15. Neutral beam dump with cathodic arc titanium gettering

    SciTech Connect (OSTI)

    Smirnov, A.; Korepanov, S. A.; Putvinski, S. [Tri Alpha Energy Inc., Rancho Santa Margarita, California 92688 (United States); Krivenko, A. S.; Murakhtin, S. V.; Savkin, V. Ya. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation)

    2011-03-15T23:59:59.000Z

    An incomplete neutral beam capture can degrade the plasma performance in neutral beam driven plasma machines. The beam dumps mitigating the shine-through beam recycling must entrap and retain large particle loads while maintaining the beam-exposed surfaces clean of the residual impurities. The cathodic arc gettering, which provides high evaporation rate coupled with a fast time response, is a powerful and versatile technique for depositing clean getter films in vacuum. A compact neutral beam dump utilizing the titanium arc gettering was developed for a field-reversed configuration plasma sustained by 1 MW, 20-40 keV neutral hydrogen beams. The titanium evaporator features a new improved design. The beam dump is capable of handling large pulsed gas loads, has a high sorption capacity, and is robust and reliable. With the beam particle flux density of 5 x 10{sup 17} H/(cm{sup 2}s) sustained for 3-10 ms, the beam recycling coefficient, defined as twice the ratio of the hydrogen molecular flux leaving the beam dump to the incident flux of high-energy neutral atoms, is {approx}0.7. The use of the beam dump allows us to significantly reduce the recycling of the shine-through neutral beam as well as to improve the vacuum conditions in the machine.

  16. Pitfalls of tungsten multileaf collimator in proton beam therapy

    SciTech Connect (OSTI)

    Moskvin, Vadim; Cheng, Chee-Wai; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States) and Indiana University Health Proton Therapy Center (Formerly Midwest Proton Radiotherapy Institute), Bloomington, Indiana 47408 (United States)

    2011-12-15T23:59:59.000Z

    Purpose: Particle beam therapy is associated with significant startup and operational cost. Multileaf collimator (MLC) provides an attractive option to improve the efficiency and reduce the treatment cost. A direct transfer of the MLC technology from external beam radiation therapy is intuitively straightforward to proton therapy. However, activation, neutron production, and the associated secondary cancer risk in proton beam should be an important consideration which is evaluated. Methods: Monte Carlo simulation with FLUKA particle transport code was applied in this study for a number of treatment models. The authors have performed a detailed study of the neutron generation, ambient dose equivalent [H*(10)], and activation of a typical tungsten MLC and compared with those obtained from a brass aperture used in a typical proton therapy system. Brass aperture and tungsten MLC were modeled by absorber blocks in this study, representing worst-case scenario of a fully closed collimator. Results: With a tungsten MLC, the secondary neutron dose to the patient is at least 1.5 times higher than that from a brass aperture. The H*(10) from a tungsten MLC at 10 cm downstream is about 22.3 mSv/Gy delivered to water phantom by noncollimated 200 MeV beam of 20 cm diameter compared to 14 mSv/Gy for the brass aperture. For a 30-fraction treatment course, the activity per unit volume in brass aperture reaches 5.3 x 10{sup 4} Bq cm{sup -3} at the end of the last treatment. The activity in brass decreases by a factor of 380 after 24 h, additional 6.2 times after 40 days of cooling, and is reduced to background level after 1 yr. Initial activity in tungsten after 30 days of treating 30 patients per day is about 3.4 times higher than in brass that decreases only by a factor of 2 after 40 days and accumulates to 1.2 x 10{sup 6} Bq cm{sup -3} after a full year of operation. The daily utilization of the MLC leads to buildup of activity with time. The overall activity continues to increase due to {sup 179}Ta with a half-life of 1.82 yr and thus require prolonged storage for activity cooling. The H*(10) near the patient side of the tungsten block is about 100 {mu}Sv/h and is 27 times higher at the upstream side of the block. This would lead to an accumulated dose for therapists in a year that may exceed occupational maximum permissible dose (50 mSv/yr). The value of H*(10) at the upstream surface of the tungsten block is about 220 times higher than that of the brass. Conclusions: MLC is an efficient way for beam shaping and overall cost reduction device in proton therapy. However, based on this study, tungsten seems to be not an optimal material for MLC in proton beam therapy. Usage of tungsten MLC in clinic may create unnecessary risks associated with the secondary neutrons and induced radioactivity for patients and staff depending on the patient load. A careful selection of material for manufacturing of an optimal MLC for proton therapy is thus desired.

  17. Ion source with improved primary arc collimation

    DOE Patents [OSTI]

    Dagenhart, W.K.

    1983-12-16T23:59:59.000Z

    An improved negative ion source is provided in which a self-biasing, molybdenum collimator is used to define the primary electron stream arc discharge from a filament operated at a negative potential. The collimator is located between the anode and the filament. It is electrically connected to the anode by means of an appropriate size resistor such that the collimator is biased at essentially the filament voltage during operation. Initially, the full arc voltage appears across the filament to collimator until the arc discharge strikes. Then the collimator biases itself to essentially filament potential due to current flow through the resistor thus defining the primary electron stream without intercepting any appreciable arc power. The collimator aperture is slightly smaller than the anode aperture to shield the anode from the arc power which, in the past, has caused overheating and erosion of the anode collimator during extended time pulsed-beam operation of the source. With the self-biasing collimator of this invention, the ion source may be operated from short pulse periods to steady-state without destroying the anode.

  18. Theoretical study of Diesel fuel reforming by a non-thermal arc discharge A. Lebouvier1,2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Theoretical study of Diesel fuel reforming by a non-thermal arc discharge A. Lebouvier1,2 , G anti-pollution norm namely for Diesel powered vehicles. NOx (NO, NO2,...) are very irritant pollutants- nologies purge is the use of non-thermal plasma. Plasma reforming of diesel fuel and exhaust gas mix- ture

  19. Direct Observations of the (Alpha to Gamma) Transformation at Different Input Powers in the Heat Affected Zone of 1045 C-Mn Steel Arc Welds Observed by Spatially Resolved X-Ray Diffraction

    SciTech Connect (OSTI)

    Palmer, T A; Elmer, J W

    2005-03-16T23:59:59.000Z

    Spatially Resolved X-Ray Diffraction (SRXRD) experiments have been performed during Gas Tungsten Arc (GTA) welding of AISI 1045 C-Mn steel at input powers ranging from 1000 W to 3750 W. In situ diffraction patterns taken at discreet locations across the width of the heat affected zone (HAZ) near the peak of the heating cycle in each weld show regions containing austenite ({gamma}), ferrite and austenite ({alpha}+{gamma}), and ferrite ({alpha}). Changes in input power have a demonstrated effect on the resulting sizes of these regions. The largest effect is on the {gamma} phase region, which nearly triples in width with increasing input power, while the width of the surrounding two phase {alpha}+{gamma} region remains relatively constant. An analysis of the diffraction patterns obtained across this range of locations allows the formation of austenite from the base metal microstructure to be monitored. After the completion of the {alpha} {yields} {gamma} transformation, a splitting of the austenite peaks is observed at temperatures between approximately 860 C and 1290 C. This splitting in the austenite peaks results from the dissolution of cementite laths originally present in the base metal pearlite, which remain after the completion of the {alpha} {yields} {gamma} transformation, and represents the formation of a second more highly alloyed austenite constituent. With increasing temperatures, carbon, originally present in the cementite laths, diffuses from the second newly formed austenite constituent to the original austenite constituent. Eventually, a homogeneous austenitic microstructure is produced at temperatures of approximately 1300 C and above, depending on the weld input power.

  20. In vivo interactions between tungsten microneedles and peripheral nerves

    E-Print Network [OSTI]

    Pier Nicola Sergi; Winnie Jensen; Silvestro Micera; Ken Yoshida

    2013-08-02T23:59:59.000Z

    Tungsten microneedles are currently used to insert neural electrodes into living peripheral nerves. However, the biomechanics underlying these procedures is not yet well characterized. For this reason, the aim of this work was to model the interactions between these microneedles and living peripheral nerves. A simple mathematical framework was especially provided to model both compression of the external layer of the nerve (epineurium) and the interactions resulting from penetration of the main shaft of the microneedle inside the living nerves. The instantaneous Young's modulus, compression force, the work needed to pierce the tissue, puncturing pressure, and the dynamic friction coefficient between the tungsten microneedles and living nerves were quantified starting from acute experiments, aiming to reproduce the physical environment of real implantations. Indeed, a better knowledge of the interactions between microneedles and peripheral nerves may be useful to improve the effectiveness of these insertion techniques, and could represent a key factor for designing robot-assisted procedures tailored for peripheral nerve insertion.

  1. Development of positron annihilation spectroscopy for characterizing neutron irradiated tungsten

    SciTech Connect (OSTI)

    C.N. Taylor; M. Shimada; D.W. Akers; M.W. Drigert; B.J. Merrill; Y. Hatano

    2013-05-01T23:59:59.000Z

    Tungsten samples (6 mm diameter, 0.2 mm thick) were irradiated to 0.025 and 0.3 dpa with neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Samples were then exposed to deuterium plasma in the tritium plasma experiment (TPE) at 100, 200 and 500ºC to a total fluence of 1 x 1026 m-2. Nuclear reaction analysis (NRA) and Doppler broadening positron annihilation spectroscopy (DB-PAS) were performed at various stages to characterize damage and retention. We present the first known results of neutron damaged tungsten characterized by DB-PAS in order to study defect concentration. Two positron sources, 22Na and 68Ge, probe ~58 µm and through the entire 200 µm thick samples, respectively. DB-PAS results reveal clear differences between the various irradiated samples. These results, and the calibration of DB-PAS to NRA data are presented.

  2. Studies on nickel-tungsten oxide thin films

    SciTech Connect (OSTI)

    Usha, K. S. [Department of Physics, Alagappa University, Karaikudi - 630 004 (India); Sivakumar, R., E-mail: krsivakumar1979@yahoo.com [Directorate of Distance Education, Alagappa University, Karaikudi - 630 004 (India); Sanjeeviraja, C. [Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi - 630 004 (India)

    2014-10-15T23:59:59.000Z

    Nickel-Tungsten oxide (95:5) thin films were prepared by rf sputtering at 200W rf power with various substrate temperatures. X-ray diffraction study reveals the amorphous nature of films. The substrate temperature induced decrease in energy band gap with a maximum transmittance of 71%1 was observed. The Micro-Raman study shows broad peaks at 560 cm{sup ?1} and 1100 cm{sup ?1} correspond to Ni-O vibration and the peak at 860 cm{sup ?1} can be assigned to the vibration of W-O-W bond. Photoluminescence spectra show two peaks centered on 420 nm and 485 nm corresponding to the band edge emission and vacancies created due to the addition of tungsten, respectively.

  3. Ion source based on the cathodic arc

    DOE Patents [OSTI]

    Sanders, D.M.; Falabella, S.

    1994-02-01T23:59:59.000Z

    A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.

  4. Photoionization of the valence shells of the neutral tungsten atom

    E-Print Network [OSTI]

    Ballance, Connor P

    2015-01-01T23:59:59.000Z

    Results from large-scale theoretical cross section calculations for the total photoionization of the 4f, 5s, 5p and 6s orbitals of the neutral tungsten atom using the Dirac Coulomb R-matrix approximation (DARC: Dirac-Atomic R-matrix codes) are presented. Comparisons are made with previous theoretical methods and prior experimental measurements. In previous experiments a time-resolved dual laser approach was employed for the photo-absorption of metal vapours and photo-absorption measurements on tungsten in a solid, using synchrotron radiation. The lowest ground state level of neutral tungsten is $\\rm 5p^6 5d^4 6s^2 \\; {^5}D_{\\it J}$, with $\\it J$=0, and requires only a single dipole matrix for photoionization. To make a meaningful comparison with existing experimental measurements, we statistically average the large-scale theoretical PI cross sections from the levels associated with the ground state $\\rm 5p^6 5d^4 6s^2 \\; {^5}D_{\\it J}[{\\it J}=0,1,2,3,4]$ levels and the $\\rm 5d^56s \\; ^7S_3$ excited metastable...

  5. Synthesis, Crystal Structure, and Elastic Properties of Novel Tungsten Nitrides

    SciTech Connect (OSTI)

    Wang, Shanmin; Yu, Xiaohui; Lin, Zhijun; Zhang, Ruifeng; He, Duanwei; Qin, Jiaqian; Zhu, Jinlong; Han, Jiantao; Wang, Lin; Mao, Ho-kwang; Zhang, Jianzhong; Zhao, Yusheng (UNLV); (Ehime U); (CIW); (Sichuan U.); (LANL)

    2012-12-13T23:59:59.000Z

    Among transition metal nitrides, tungsten nitrides possess unique and/or superior chemical, mechanical, and thermal properties. Preparation of these nitrides, however, is challenging because the incorporation of nitrogen into tungsten lattice is thermodynamically unfavorable at atmospheric pressure. To date, most materials in the W-N system are in the form of thin films produced by nonequilibrium processes and are often poorly crystallized, which severely limits their use in diverse technological applications. Here we report synthesis of tungsten nitrides through new approaches involving solid-state ion exchange and nitrogen degassing under pressure. We unveil a number of novel nitrides including hexagonal and rhombohedral W{sub 2}N{sub 3}. The final products are phase-pure and well-crystallized in bulk forms. For hexagonal W{sub 2}N{sub 3}, hexagonal WN, and cubic W3N4, they exhibit elastic properties rivaling or even exceeding cubic-BN. All four nitrides are prepared at a moderate pressure of 5 GPa, the lowest among high-pressure synthesis of transition metal nitrides, making it practically feasible for massive and industrial-scale production.

  6. Arc Geometry and Algebra: Foliations, Moduli ... - Purdue University

    E-Print Network [OSTI]

    2012-07-04T23:59:59.000Z

    the simplicial complex which has one simplex for each arc family ? with the i–the face ..... 1.6.2 Loop graph of an arc family: A geometric construction of the dual.

  7. NEW NUMERICAL TECHNOLOGIES FOR THE SIMULATION OF ARC WELDING PROCESSES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    NEW NUMERICAL TECHNOLOGIES FOR THE SIMULATION OF ARC WELDING PROCESSES Michel Bellet 1 , Makhlouf Antipolis, France; soudage@transvalor.com Keywords: welding, finite elements, material deposit, adaptive for arc welding simulation and analysis. The new numerical technologies essentially consist first

  8. arc ion sources: Topics by E-print Network

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

    and performance of vacuum arc ion sources. Brown, I 2013-01-01 2 Development of High Efficiency Versatile Arc Discharge Ion Source (VADIS) at CERN Isolde CERN Preprints Summary: We...

  9. arc ion source: Topics by E-print Network

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

    and performance of vacuum arc ion sources. Brown, I 2013-01-01 2 Development of High Efficiency Versatile Arc Discharge Ion Source (VADIS) at CERN Isolde CERN Preprints Summary: We...

  10. Correlations between SAR arc intensity and solar and geomagnetic activity

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ±1960, Rees and Akasofu (1963) and Roach and Roach (1963) found that there are correlations of the SAR arc

  11. The Inception of the ArcGIS Marine Data Model

    E-Print Network [OSTI]

    Wright, Dawn Jeannine

    . Shapefiles and coverages can now be easily loaded as feature classes in the ArcGISTM geodatabase for more

  12. An SF6 autoexpansion breaker; The correlation between magnetic arc control and critical current

    SciTech Connect (OSTI)

    Bernard, G.; Girard, A.; Malkin, P. (Etablissements Merlin et Gerin, 38 - Grenoble (France)); Scarpa, P. (Univ. of Liege (BE))

    1990-01-01T23:59:59.000Z

    It is possible to design SF6 autoexpansion breakers which are free from critical currents. In these devices which combine arc rotation in a magnetic field and thermal expansion of gas, critical currents can effectively occur if these effects are incorrectly created and combined. An analytic and experimental method optimizing the current at which rotation should start is presented. The study of the gas flow then ensures coupling with expansion. These investigations lead to representation of a thermal time constant directly related to interrupting capacity.

  13. Way to reduce arc voltage losses in hybrid thermionic converters

    SciTech Connect (OSTI)

    Tskhakaya, V.K.; Yarygin, V.I.

    1982-03-01T23:59:59.000Z

    Experimental results are reported concerning the output and emission characteristics of the arc and hybrid regimes in a plane-parallel thermionic converter with Pt--Zr--O electrode pair. It is shown that arc voltage losses can be reduced to values below those obtainable in ordinary arc thermionic converters.

  14. Evaluation of the clinical usefulness of modulated Arc treatment

    E-Print Network [OSTI]

    Lee, Young Kyu; Kim, Yeon Sil; Choi, Byung Ock; Nam, Sang Hee; Park, Hyeong Wook; Kim, Shin Wook; Shin, Hun Joo; Lee, Jae Choon; Kim, Ji Na; Park, Sung Kwang; Kim, Jin Young; Kang, Young-Nam

    2015-01-01T23:59:59.000Z

    The purpose of this study is to evaluate the clinical usefulness of modulated arc (mARC) treatment techniques. The mARC treatment plans of the non-small cell lung cancer (NSCLC) patients were performed in order to verify the clinical usefulness of mARC. A pre study was conducted to find the most competent plan condition of mARC treatment and the usefulness of mARC treatment plan was evaluated by comparing it with the other Arc treatment plans such as Tomotherapy and RapidArc. In the case of mARC, the optimal condition for the mARC plan was determined by comparing the dosimetric performance of the mARC plans with the use of various parameters. The various parameters includes the photon energies (6 MV, 10 MV), optimization point angle (6{\\deg}-10{\\deg} intervals), and total segment number (36-59 segment). The best dosimetric performance of mARC was observed at 10 MV photon energy and the point angle 6 degree, and 59 segments. The each treatment plans of three different techniques were compared with the followin...

  15. Costing of Joining Methods -Arc Welding Costs

    E-Print Network [OSTI]

    Colton, Jonathan S.

    Costing of Joining Methods - Arc Welding Costs ver. 1 ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 1 #12;OverviewOverview · Cost components · Estimation of costsEstimation of costs · Examples ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 2 #12;Cost

  16. Energy Savings in Electric Arc Furnace Melting

    E-Print Network [OSTI]

    Lubbeck, W.

    1982-01-01T23:59:59.000Z

    Arc furnace melting which at one time was almost exclusively used to produce alloy steel and steel castings is now widely accepted in the industry as an efficient process to produce all types of steel and iron. Presently, about 28% of steel...

  17. Pairing, pseudogap and Fermi arcs in cuprates

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

    Kaminski, Adam; Gu, Genda; Kondo, Takeshi; Takeuchi, Tsunehiro

    2014-10-31T23:59:59.000Z

    We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below Tpair ~ 150K and significantly above Tc, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below Tpair, and its interplay with strong scatteringmore »creates “artificial” Fermi arcs for Tc pair. However, above Tpair, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. We demonstrate that these findings resolve a number of seemingly contradictory scenarios.« less

  18. Driven Motion and Instability of an Atmospheric Pressure Arc

    SciTech Connect (OSTI)

    Max Karasik

    1999-12-01T23:59:59.000Z

    Atmospheric pressure arcs are used extensively in applications such as welding and metallurgy. However, comparatively little is known of the physics of such arcs in external magnetic fields and the mechanisms of the instabilities present. In order to address questions of equilibrium and stability of such arcs, an experimental arc furnace is constructed and operated in air with graphite cathode and steel anode at currents 100-250 A. The arc is diagnosed with a gated intensified camera and a collimated photodiode array, as well as fast voltage and current probes.

  19. Nmr Study of Thiocarbonyl Derivatives of Fe and Mn were made with solutions of the tungsten and molybdenum species

    E-Print Network [OSTI]

    Bodner, George M.

    Nmr Study of Thiocarbonyl Derivatives of Fe and Mn were made with solutions of the tungsten.g.. the tungsten ion readily oxidizes in aqueous acid [A. Samotus and B. Kosowicz-Czajkowska, Rocz. Chem., 45, 1623

  20. Comparison of QM-Only and QM/MM Models for the Mechanism of Tungsten-Dependent Acetylene Hydratase

    E-Print Network [OSTI]

    Liao, Rongzhen

    Comparison of QM-Only and QM/MM Models for the Mechanism of Tungsten-Dependent Acetylene Hydratase study on the formation of vinyl alcohol in the catalytic cycle of tungsten-dependent acetylene hydratase

  1. Preparation of hexagonal WO{sub 3} from hexagonal ammonium tungsten bronze for sensing NH{sub 3}

    SciTech Connect (OSTI)

    Szilagyi, Imre Miklos [Materials Structure and Modeling Research Group of the Hungarian Academy of Sciences, Budapest University of Technology and Economics, H-1111 Budapest, Szt. Gellert ter 4 (Hungary)], E-mail: imre.szilagyi@mail.bme.hu; Wang Lisheng; Gouma, Pelagia-Irene [Department of Materials Science and Engineering, 314 Old Engineering Building, SUNY, Stony Brook, NY 11794-2275 (United States); Balazsi, Csaba [Ceramics and Nanocomposites Laboratory, Research Institute for Technical Physics and Materials Science, H-1121 Budapest, Konkoly-Thege ut 29-33 (Hungary); Madarasz, Janos; Pokol, Gyoergy [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1111 Budapest, Szt. Gellert ter 4 (Hungary)

    2009-03-05T23:59:59.000Z

    Hexagonal tungsten oxide (h-WO{sub 3}) was prepared by annealing hexagonal ammonium tungsten bronze, (NH{sub 4}){sub 0.07}(NH{sub 3}){sub 0.04}(H{sub 2}O){sub 0.09}WO{sub 2.95}. The structure, composition and morphology of h-WO{sub 3} were studied by XRD, XPS, Raman, {sup 1}H MAS (magic angle spinning) NMR, scanning electron microscopy (SEM), and BET-N{sub 2} specific surface area measurement, while its thermal stability was investigated by in situ XRD. The h-WO{sub 3} sample was built up by 50-100 nm particles, had an average specific surface area of 8.3 m{sup 2}/g and was thermally stable up to 450 deg. C. Gas sensing tests showed that h-WO{sub 3} was sensitive to various levels (10-50 ppm) of NH{sub 3}, with the shortest response and recovery times (1.3 and 3.8 min, respectively) to 50 ppm NH{sub 3}. To this NH{sub 3} concentration, the sensor had significantly higher sensitivity than h-WO{sub 3} samples prepared by wet chemical methods.

  2. Modelling of Melt Damage of Tungsten Armour under Multiple Transients Expected in ITER and Validations Against JET-ILW Experiments

    E-Print Network [OSTI]

    Modelling of Melt Damage of Tungsten Armour under Multiple Transients Expected in ITER and Validations Against JET-ILW Experiments

  3. Bulk Tungsten in the JET Divertor: Potential Influence of the Exhaustion of Ductility and Grain Growth on the Lifetime

    E-Print Network [OSTI]

    Bulk Tungsten in the JET Divertor: Potential Influence of the Exhaustion of Ductility and Grain Growth on the Lifetime

  4. The Structure of the Tungsten Coatings Deposited by Combined Magnetron Sputtering and Ion Implantation for Nuclear Fusion Applications

    E-Print Network [OSTI]

    The Structure of the Tungsten Coatings Deposited by Combined Magnetron Sputtering and Ion Implantation for Nuclear Fusion Applications

  5. 3-D Finite Element Electromagnetic and Stress Analyses of the JET LB-SRP Divertor Element (Tungsten Lamella Design)

    E-Print Network [OSTI]

    3-D Finite Element Electromagnetic and Stress Analyses of the JET LB-SRP Divertor Element (Tungsten Lamella Design)

  6. Theoretical Description of Heavy Impurity Transport and its Application to the Modelling of Tungsten in JET and ASDEX Upgrade

    E-Print Network [OSTI]

    Theoretical Description of Heavy Impurity Transport and its Application to the Modelling of Tungsten in JET and ASDEX Upgrade

  7. Shower characteristics of particles with momenta from up to 100 GeV in the CALICE Scintillator-Tungsten HCAL

    E-Print Network [OSTI]

    Klempt W

    2015-01-01T23:59:59.000Z

    Shower characteristics of particles with momenta from up to 100 GeV in the CALICE Scintillator-Tungsten HCAL

  8. Clamping of Solid Tungsten Components for the Bulk W Divertor Row in JET – Precautionary Design for a Brittle Material

    E-Print Network [OSTI]

    Clamping of Solid Tungsten Components for the Bulk W Divertor Row in JET – Precautionary Design for a Brittle Material

  9. Soft X-Ray Tomographic Reconstruction of JET ILW Plasmas with Tungsten Impurity and Different Spectral Response of Detectors

    E-Print Network [OSTI]

    Soft X-Ray Tomographic Reconstruction of JET ILW Plasmas with Tungsten Impurity and Different Spectral Response of Detectors

  10. Power Handling of the Bulk Tungsten Divertor Row at JET: First Measurements and Comparison to the GTM Thermal Model

    E-Print Network [OSTI]

    Power Handling of the Bulk Tungsten Divertor Row at JET: First Measurements and Comparison to the GTM Thermal Model

  11. Positron-production Experiment In Tungsten Crystal Using 4 And 8-gev Channeling Electrons At The Kekb Injector Linac

    E-Print Network [OSTI]

    Suwada, T; Chehab, R; Enomoto, A; Furukawa, K; Kakihara, K; Kamitani, T; Ogawa, Y; Ohsawa, S; Okuno, H; Oogoe, T; Fujita, T; Umemori, K; Yoshida, K; Ababiy, V; Potylitsin, A P; Vnukov, I E; Hamatsu, R; Sasahara, K

    2002-01-01T23:59:59.000Z

    Positron-production Experiment In Tungsten Crystal Using 4 And 8-gev Channeling Electrons At The Kekb Injector Linac

  12. Positron-production Experiment By 8-gev Channeling Electrons In Crystal Tungsten At The Kekb Injector Linac

    E-Print Network [OSTI]

    Suwada, T

    2001-01-01T23:59:59.000Z

    Positron-production Experiment By 8-gev Channeling Electrons In Crystal Tungsten At The Kekb Injector Linac

  13. Hydrogen interaction with point defects in tungsten K. Heinola, T. Ahlgren, K. Nordlund, and J. Keinonen

    E-Print Network [OSTI]

    Nordlund, Kai

    Hydrogen interaction with point defects in tungsten K. Heinola, T. Ahlgren, K. Nordlund, and J-principles calculations were used in determining the binding and trapping properties of hydrogen to point defects in tungsten. Hydrogen zero-point vibrations were taken into account. It was concluded that the monovacancy can

  14. Review on the EFDA programme on tungsten materials technology and science M. Rieth a,

    E-Print Network [OSTI]

    Nordlund, Kai

    Review on the EFDA programme on tungsten materials technology and science M. Rieth a, , J design studies for helium cooled divertors utilize tungsten materials and alloys, mainly due structural as well as armor materials in combination with the necessary production and fab- rication

  15. Dynamics of femtosecond laser produced tungsten nanoparticle plumes S. S. Harilal,1

    E-Print Network [OSTI]

    Harilal, S. S.

    Dynamics of femtosecond laser produced tungsten nanoparticle plumes S. S. Harilal,1 N. Farid,1,2 A tungsten nanoparticle plumes in vacuum. Fast gated images showed distinct two components expansion features.1063/1.4833564] I. INTRODUCTION Nanoparticle production and application research is an area of significant

  16. Effect of ion mass and charge state on transport of vacuum ARC plasmas through a biased magnetic filter

    SciTech Connect (OSTI)

    Byon, Eungsun; Kim, Jong-Kuk; Kwon, Sik-Chol; Anders, Andre

    2003-12-01T23:59:59.000Z

    The effect of ion mass and charge state on plasma transport through a 90{sup o}-curved magnetic filter is experimentally investigated using a pulsed cathodic arc source. Graphite, copper, and tungsten were selected as test materials. The filter was a bent copper coil biased via the voltage drop across a low-ohm, ''self-bias'' resistor. Ion transport is accomplished via a guiding electric field, whose potential forms a ''trough'' shaped by the magnetic guiding field of the filter coil. Evaluation was done by measuring the filtered ion current and determination of the particle system coefficient, which can be defined as the ratio of filter ion current, divided by the mean ion charge state, to the arc current. It was found that the ion current and particle system coefficient decreased as the mass-to-charge ratio of ions increased. This result can be qualitatively interpreted by a very simply model of ion transport that is based on compensation of the centrifugal force by the electric force associated with the guiding potential trough.

  17. INSTITUTE OF PHYSICS PUBLISHING MEASUREMENT SCIENCE AND TECHNOLOGY Meas. Sci. Technol. 15 (2004) 991999 PII: S0957-0233(04)74770-0

    E-Print Network [OSTI]

    Zhang, YuMing

    2004-01-01T23:59:59.000Z

    for accurate control of heat input. As a close relative and modification of GTAW, plasma arc welding (PAW) has, penetration 1. Introduction Gas tungsten arc welding (GTAW) is the primary process for precision joining of metals due to its capability for accurate control of heat input. Although plasma arc welding (PAW

  18. X-ray diffraction study of the static strength of tungsten to 69 GPa Duanwei He* and Thomas S. Duffy

    E-Print Network [OSTI]

    Duffy, Thomas S.

    X-ray diffraction study of the static strength of tungsten to 69 GPa Duanwei He* and Thomas S of tungsten was determined under static high pressures to 69 GPa using x-ray diffraction techniques strength of tungsten increases with compression, reaching a value of 5.3 GPa at the highest pressure

  19. TUNGSTEN AND HAFNIUM DISTRIBUTION IN CALCIUM-ALUMINUM INCLUSIONS (CAIs) FROM ALLENDE AND EFREMOVKA. M. Humayun1

    E-Print Network [OSTI]

    Grossman, Lawrence

    TUNGSTEN AND HAFNIUM DISTRIBUTION IN CALCIUM-ALUMINUM INCLUSIONS (CAIs) FROM ALLENDE AND EFREMOVKA with, or even earlier than, metal from CAIs and chondrules [3]. Tungsten isotope compositions represent veins [5]. Tungsten mobility is cause for concern, but is not sufficient evidence against the Kleine et

  20. Z .Surface and Coatings Technology 130 2000 164 172 Production of high-density Ni-bonded tungsten carbide

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    Z .Surface and Coatings Technology 130 2000 164 172 Production of high-density Ni-bonded tungsten spraying; Nickel; Tungsten carbide 1. Introduction 1.1. General Since the mid-1990s, the market share of cemented Z .carbides has surpassed that of high-speed steels HSS , Z .with tungsten carbide WC having 50

  1. By Earle B. Amey Tungsten's unique high-temperature properties are beneficial The Office of the United States Trade Representative

    E-Print Network [OSTI]

    of tungsten ore concentrates and products with that of 1994. Demand generally increased in the cemented from products under these tariffs. during 1995. During 1995, prices for tungsten concentrates, which had built from 1985). Major Domestic production data for tungsten were developed by the liquidation of both

  2. By Earle B. Amey Tungsten's unique high-temperature in Metal Bulletin (London). ferrotungsten, carbide powder blends, and

    E-Print Network [OSTI]

    of a stronger tungsten market, at certain forms of waste and scrap. production of numerous end-use items of the U.S. economy influenced the overall increase in demand for tungsten products during 1994. The antidumping tariffs on imports of tungsten ore concentrates and products from China, initially imposed

  3. ENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR LINAC

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    by these stimulating results, we proceeded to systematic studies on the positron-production efficiencies with tungstenENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR, Russia R. Chehab, IPNL, IN2P3-CNRS, Universite Claude Bernald 1, France Abstract A new tungsten single

  4. Dynamics of femtosecond laser produced tungsten nanoparticle plumes

    SciTech Connect (OSTI)

    Harilal, S. S.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)] [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Farid, N. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States) [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); School of Physics and Optical Engineering, Dalian University of Technology, Dalian 116024 (China); Kozhevin, V. M. [Ioffe Physics Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)] [Ioffe Physics Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)

    2013-11-28T23:59:59.000Z

    We investigated the expansion features of femtosecond laser generated tungsten nanoparticle plumes in vacuum. Fast gated images showed distinct two components expansion features, viz., plasma and nanoparticle plumes, separated by time of appearance. The persistence of plasma and nanoparticle plumes are ?500 ns and ?100 ?s, respectively, and propagating with velocities differed by 25 times. The estimated temperature of the nanoparticles showed a decreasing trend with increasing time and space. Compared to low-Z materials (e.g., Si), ultrafast laser ablation of high-Z materials like W provides significantly higher nanoparticle yield. A comparison between the nanoparticle plumes generated by W and Si is also discussed along with other metals.

  5. Electrodeposited tungsten-nickel-boron: A replacement for hexavalent chromium

    SciTech Connect (OSTI)

    Steffani, C.; Meltzer, M.

    1995-04-01T23:59:59.000Z

    Chromium, deposited from acidic solutions of its hexavalent ion, has been the rule for wear resistant, corrosion resistant coatings for many years. Although chromium coatings are durable, the plating process generates air emissions, effluent rinse waters, and process solutions that are toxic, suspected carcinogens, and a risk to human health and the environment. Tungsten-nickel-boron (W-Ni-B) alloy deposition is a potential substitute for hexavalent chrome. It has excellent wear, corrosion, and mechanical properties and also may be less of an environmental risk. This study examines the electroplating process and deposit properties of W-Ni-B and compares them with those of hexavalent chrome.

  6. Detection of the Natural Alpha Decay of Tungsten

    E-Print Network [OSTI]

    C. Cozzini; G. Angloher; C. Bucci; F. von Feilitzsch; D. Hauff; S. Henry; Th. Jagemann; J. Jochum; H. Kraus; B. Majorovits; V. Mikhailik; J. Ninkovic; F. Petricca; W. Potzel; F. Proebst; Y. Ramachers; W. Rau; M. Razeti; W. Seidel; M. Stark; L. Stodolsky; A. J. B. Tolhurst; W. Westphal; H. Wulandari

    2004-10-26T23:59:59.000Z

    The natural alpha decay of 180W has been unambiguously detected for the first time. The alpha peak is found in a (gamma,beta and neutron)-free background spectrum. This has been achieved by the simultaneous measurement of phonon and light signals with the CRESST cryogenic detectors. A half-life of T1/2 = (1.8 +- 0.2) x 10^18 y and an energy release of Q = (2516.4 +- 1.1 (stat.) +- 1.2 (sys.)) keV have been measured. New limits are also set on the half-lives of the other naturally occurring tungsten isotopes.

  7. Electronic and structural properties of ultrathin tungsten nanowires and nanotubes by density functional theory calculation

    SciTech Connect (OSTI)

    Sun, Shih-Jye [Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan (China); Lin, Ken-Huang; Li, Jia-Yun [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Ju, Shin-Pon, E-mail: jushin-pon@mail.nsysu.edu.tw [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2014-10-07T23:59:59.000Z

    The simulated annealing basin-hopping method incorporating the penalty function was used to predict the lowest-energy structures for ultrathin tungsten nanowires and nanotubes of different sizes. These predicted structures indicate that tungsten one-dimensional structures at this small scale do not possess B.C.C. configuration as in bulk tungsten material. In order to analyze the relationship between multi-shell geometries and electronic transfer, the electronic and structural properties of tungsten wires and tubes including partial density of state and band structures which were determined and analyzed by quantum chemistry calculations. In addition, in order to understand the application feasibility of these nanowires and tubes on nano-devices such as field emitters or chemical catalysts, the electronic stability of these ultrathin tungsten nanowires was also investigated by density functional theory calculations.

  8. Electrical Safety and Arc Flash Protections

    SciTech Connect (OSTI)

    R. Camp

    2008-03-04T23:59:59.000Z

    Over the past four years, the Electrical Safety Program at PPPL has evolved in addressing changing regulatory requirements and lessons learned from accident events, particularly in regards to arc flash hazards and implementing NFPA 70E requirements. This presentation will discuss PPPL's approaches to the areas of electrical hazards evaluation, both shock and arc flash; engineered solutions for hazards mitigation such as remote racking of medium voltage breakers, operational changes for hazards avoidance, targeted personnel training and hazard appropriate personal protective equipment. Practical solutions for nominal voltage identification and zero voltage checks for lockout/tagout will also be covered. Finally, we will review the value of a comprehensive electrical drawing program, employee attitudes expressed as a personal safety work ethic, integrated safety management, and sustained management support for continuous safety improvement.

  9. Recent advances in vacuum arc ion sources

    SciTech Connect (OSTI)

    Brown, I.G.; Anders, A.; Anders, S.; Dickinson, M.R.; MacGill, R.A.; Oks, E.M.

    1995-07-01T23:59:59.000Z

    Intense beams of metal ions can be formed from a vacuum arc ion source. Broadbeam extraction is convenient, and the time-averaged ion beam current delivered downstream can readily be in the tens of milliamperes range. The vacuum arc ion source has for these reasons found good application for metallurgical surface modification--it provides relatively simple and inexpensive access to high dose metal ion implantation. Several important source developments have been demonstrated recently, including very broad beam operation, macroparticle removal, charge state enhancement, and formation of gaseous beams. The authors have made a very broad beam source embodiment with beam formation electrodes 50 cm in diameter, producing a beam of width {approximately}35 cm for a nominal beam area of {approximately}1,000 cm{sup 2}, and a pulsed Ti beam current of about 7 A was formed at a mean ion energy of {approximately}100 keV. Separately, they`ve developed high efficiency macroparticle-removing magnetic filters and incorporated such a filter into a vacuum arc ion source so as to form macroparticle-free ion beams. Jointly with researchers at the High Current Electronics Institute at Tomsk, Russia, and the Gesellschaft fuer Schwerionenforschung at Darmstadt, Germany, they`ve developed a compact technique for increasing the charge states of ions produced in the vacuum arc plasma and thus providing a simple means of increasing the ion energy at fixed extractor voltage. Finally, operation with mixed metal and gaseous ion species has been demonstrated. Here, they briefly review the operation of vacuum marc ion sources and the typical beam and implantation parameters that can be obtained, and describe these source advances and their bearing on metal ion implantation applications.

  10. Atomic data of tungsten for current and future uses in fusion and plasma science

    SciTech Connect (OSTI)

    Clementson, J.; Beiersdorfer, P. [Physics Division, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551 (United States); Lennartsson, T. [Lund Observatory, Lund University, P.O. Box 43, SE-221 00 Lund (Sweden)

    2013-04-19T23:59:59.000Z

    Atomic physics has played an important role throughout the history of experimental plasma physics. For example, accurate knowledge of atomic properties has been crucial for understanding the plasma energy balance and for diagnostic development. With the shift in magnetic fusion research toward high-temperature burning plasmas like those expected to be produced in the ITER tokamak, the atomic physics of tungsten has become important. Tungsten will be a constituent of ITER plasmas because of its use as a plasma-facing material able to withstand high heat loads with lower tritium retention than other possible materials. Already, ITER diagnostics are being developed based on using tungsten radiation. In particular, the ITER Core Imaging X-ray Spectrometer (CIXS), which is designed to measure the core ion temperature and bulk plasma motion, is being based on the x-ray emission of neonlike tungsten ions (W{sup 64+}). In addition, tungsten emission will at ITER be measured by extreme ultraviolet (EUV) and optical spectrometers to determine its concentration in the plasma and to assess power loss and tungsten sputtering rates. On present-day tokamaks tungsten measurements are therefore being performed in preparation of ITER. Tungsten has very complex spectra and most are still unknown. The WOLFRAM project at Livermore aims to produce data for tungsten in various spectral bands: Lshell x-ray emission for CIXS development, soft x-ray and EUV M- and N-shell tungsten emission for understanding the edge radiation from ITER plasmas as well as from contemporary tokamaks, and O-shell emission for developing spectral diagnostics of the ITER divertor.

  11. Arc melter demonstration baseline test results

    SciTech Connect (OSTI)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; Oden, L.L.; O`Connor, W.K.; Turner, P.C.

    1994-07-01T23:59:59.000Z

    This report describes the test results and evaluation for the Phase 1 (baseline) arc melter vitrification test series conducted for the Buried Waste Integrated Demonstration program (BWID). Phase 1 tests were conducted on surrogate mixtures of as-incinerated wastes and soil. Some buried wastes, soils, and stored wastes at the INEL and other DOE sites, are contaminated with transuranic (TRU) radionuclides and hazardous organics and metals. The high temperature environment in an electric arc furnace may be used to process these wastes to produce materials suitable for final disposal. An electric arc furnace system can treat heterogeneous wastes and contaminated soils by (a) dissolving and retaining TRU elements and selected toxic metals as oxides in the slag phase, (b) destroying organic materials by dissociation, pyrolyzation, and combustion, and (c) capturing separated volatilized metals in the offgas system for further treatment. Structural metals in the waste may be melted and tapped separately for recycle or disposal, or these metals may be oxidized and dissolved into the slag. The molten slag, after cooling, will provide a glass/ceramic final waste form that is homogeneous, highly nonleachable, and extremely durable. These features make this waste form suitable for immobilization of TRU radionuclides and toxic metals for geologic timeframes. Further, the volume of contaminated wastes and soils will be substantially reduced in the process.

  12. Welding Development W87 Baseline

    SciTech Connect (OSTI)

    A. Newman; G. Gibbs; G. K. Hicken

    1998-11-01T23:59:59.000Z

    This report covers the development activities used to qualify the Gas Tungsten Arc (FTA) girth weld and the resistance stem attachments on the W87 Base Line (W87BL). Design of experiments was used throughout the development activities.

  13. Chromatic instabilities in cesium-doped tungsten bronze nanoparticles

    SciTech Connect (OSTI)

    Adachi, Kenji, E-mail: kenji-adachi@ni.smm.co.jp; Ota, Yosuke; Tanaka, Hiroyuki; Okada, Mika; Oshimura, Nobumitsu; Tofuku, Atsushi [Ichikawa Research Laboratories, Sumitomo Metal Mining Co., Ltd., Ichikawa 272-8588 (Japan)

    2013-11-21T23:59:59.000Z

    Nanoparticles of alkali-doped tungsten bronzes are an excellent near-infrared shielding material, but exhibit slight chromatic instabilities typically upon applications of strong ultra-violet light or heating in humid environment, which acts detrimentally to long-life commercial applications. Origin of the chromatic instabilities in cesium-doped tungsten bronze has been investigated, and it has been found that the coloration and bleaching processes comprised electronic exchanges which accelerate or depress the polaron excitation and the localized surface plasmon resonance. Coloration on UV illumination is evidenced by electron diffraction as due to the formation of H{sub x}WO{sub 3}, which is considered to take place in the surface Cs-deficient WO{sub 3} region via the double charge injection mechanism. On the other hand, bleaching on heating in air and in humid environment is shown to accompany the extraction of Cs and electrons from Cs{sub 0.33}WO{sub 3} by X-ray photoelectron spectroscopy and X-ray diffraction analysis and is concluded to be an oxidation of Cs{sub 0.33}WO{sub 3} on the particle surface.

  14. Facile Synthesis of a Tungsten Alkylidyne Catalyst for Alkyne Zachary J. Tonzetich, Yan Choi Lam, Peter Muller, and Richard R. Schrock*

    E-Print Network [OSTI]

    Müller, Peter

    Facile Synthesis of a Tungsten Alkylidyne Catalyst for Alkyne Metathesis Zachary J. Tonzetich, Yan cis double bonds. Tungsten alkylidyne trialkoxide alkyne metathesis catalysts were discovered in 1981 of cleavage of a tungsten-tungsten triple bond upon reaction with an alkyne or nitrile.9 Recent advances

  15. Rapid mapping tool : an ArcMap extension /

    SciTech Connect (OSTI)

    Linger, S. P. (Steve P.); Rich, P. M. (Paul M.); Walther, D. (Douglas); Witkowski, M. S. (Marc S.); Jones, M. A. (Marcia A.); Khalsa, H. S. (Hari S.)

    2002-01-01T23:59:59.000Z

    Cartographic production laboratories produce large volumes of maps for diverse customers. Turnaround time and consistency are key concerns. The Rapid Mapping Tool is an ArcMap based tool that enables rapid creation of maps to meet customer needs. This tool was constructed using VB/VBA, ArcObjects, and ArcGIS templates. The core capability of ArcMap is extended for custom map production by storing specifications associated with a map or template in a companion XML document. These specifications include settings and preferences used to create custom maps. The tool was developed as a component of an enterprise GIS, which enables spatial data management and delivery using ArcSDE, ArcIMS, Oracle, and a web-based request tracking system.

  16. Influence of argon and oxygen on charge-state-resolved ion energy distributions of filtered aluminum arcs

    E-Print Network [OSTI]

    Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil; Schneider, Jochen M.

    2006-01-01T23:59:59.000Z

    energy distributions of filtered aluminum arcs Johanna Roséndistributions (IEDs) in filtered aluminum vacuum arc plasmasfor vacuum arc plasmas. Aluminum plasma, for example,

  17. A Dynamic Traveling Salesman Problem with Stochastic Arc Costs

    E-Print Network [OSTI]

    Alejandro Toriello

    2012-08-31T23:59:59.000Z

    Aug 31, 2012 ... Abstract: We propose a dynamic traveling salesman problem (TSP) with stochastic arc costs motivated by applications, such as dynamic ...

  18. arc generated carbon: Topics by E-print Network

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

    as a single storage endpoint and a pool of distributed computing nodes. The next generation ARC middleware with its several new technologies provides new possibilities in...

  19. arc magmatism isotopic: Topics by E-print Network

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

    J. 3 TECTONIC CONTROLS OF GEOCHEMICAL EVOLUTION IN ARC MAGMATISM OF SE ASIA 359Bali, Indonesia, 10 -13 October 1999PACRIM 99 Geosciences Websites Summary: processes operating at...

  20. andean arc magmatism: Topics by E-print Network

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

    J. 3 TECTONIC CONTROLS OF GEOCHEMICAL EVOLUTION IN ARC MAGMATISM OF SE ASIA 359Bali, Indonesia, 10 -13 October 1999PACRIM 99 Geosciences Websites Summary: processes operating at...

  1. arc lamp heal: Topics by E-print Network

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

    Cultures) -- (Animal Behaviour Wang, Yan 40 Spatial and time-dependent distribution of plasma parameters in the metal-halide arc lamp. Physics Websites Summary: for the...

  2. PV Arc Fault Detector Challenges Due to Module Frequency Response...

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

    This poster does not contain any proprietary or confidential information. Introduction PV system arc faults have led to a number of rooftop fires which have caused significant...

  3. PHOTOVOLTAIC DC ARC FAULT DETECTOR TESTING AT SANDIA NATIONAL

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

    PHOTOVOLTAIC DC ARC FAULT DETECTOR TESTING AT SANDIA NATIONAL LABORATORIES Jay Johnson 1 , Birger Pahl 2 , Charles Luebke 2 , Tom Pier 2 , Theodore Miller 3 , Jason Strauch 1 ,...

  4. Sandia National Laboratories: photovoltaic direct-current arc...

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

    Program Goals IndustryCollaboration FutureCollaborations Publications Contacts Photovoltaic (PV) arc-faults can lead to fires, damage property, and threaten the safety of...

  5. Preparation of dinitrogen, hydrido, and carbonyl complexes of molybdenum and tungsten from higher halides

    SciTech Connect (OSTI)

    Borisov, A.P.; Makhaev, V.D.; Semenenko, K.N.

    1988-01-20T23:59:59.000Z

    The yields, physicochemical properties, and analyses of phosphine complexes of molybdenum and tungsten are shown. The reduction of molydenum pentachloride or tungsten hexachloride with metallic magnesium in THF in the presence of a tertiary organic phosphines in an atmosphere of nitrogen, hydrogen, or carbon monoxide provided a convenient method for the preparation of dinitrogen M(N/sub 2/)/sub 2/L/sub 4/, hydride MH/sub 4/L/sub 4/, or carbonyl M(CO)/sub 6/minus/x/L/sub x/ complexes respectively of molybdenum or tungsten (M = Mo, W; L - tertiary organic phosphine).

  6. Tunable carbon nanotube-tungsten carbide nanoparticles heterostructures by vapor deposition

    SciTech Connect (OSTI)

    Xia, Min; Guo, Hongyan; Ge, Changchun [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing (China); Institute of Powder Metallurgy and Advanced Ceramics, Southwest Jiaotong University, 111, 1st Section, Northern 2nd Ring Road, Chengdu (China); Yan, Qingzhi, E-mail: qzyan@ustb.edu.cn; Lang, Shaoting [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing (China)

    2014-05-14T23:59:59.000Z

    A simple, versatile route for the synthesis of carbon nanotube (CNT)-tungsten carbide nanoparticles heterostructures was set up via vapor deposition process. For the first time, amorphous CNTs (?-CNTs) were used to immobilized tungsten carbide nanoparticles. By adjusting the synthesis and annealing temperature, ?-CNTs/amorphous tungsten carbide, ?-CNTs/W{sub 2}C, and CNTs/W{sub 2}C/WC heterostructures were prepared. This approach provides an efficient method to attach other metal carbides and other nanoparticles to carbon nanotubes with tunable properties.

  7. Iodine as a tracer of organic material: 129 I results from gas hydrate

    E-Print Network [OSTI]

    Fehn, Udo

    Iodine as a tracer of organic material: 129 I results from gas hydrate systems and fore arc fluids of this system, investigations of gas hydrates from the Peru Margin (ODP 201, Site 1230) and of fluids collected for these fluids. The results are in good agreement with earlier investigations of gas hydrate systems at Blake

  8. Hydrologic Modeling with Arc Hydro Tools 1 Copyright 2007 ESRI. All rights reserved. Arc Hydro

    E-Print Network [OSTI]

    Kane, Andrew S.

    resources applications (template data model) Culmination of a three year process led by D.R. Maidment rights reserved. Inside the Geodatabase Geodatabase Survey datasets Survey folder Survey Locators Template Data Models (30+) HEC ...FEMA Project Data Models Feature TopologyObject ArcGIS Core Data Model

  9. The ATLAS ARC backend to HPC

    E-Print Network [OSTI]

    Haug, Sigve; The ATLAS collaboration; Sciacca, Francesco Giovanni; Weber, Michele

    2015-01-01T23:59:59.000Z

    The current distributed computing resources used for simulating and processing collision data collected by the LHC experiments are largely based on dedicated x86 Linux clusters. Access to resources, job control and software provisioning mechanisms are quite different from the common concept of self-contained HPC applications run by particular users on specific HPC systems. We report on the development and the usage of a ssh back-end to the Advanced Resource Connector (ARC) middleware to enable HPC compliant access and on the corresponding software provisioning mechanisms.

  10. ScanArc ASA | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with form HistoryRistma AG Jump638324°, -122.0230146° ShowSavannahSavvasScanArc

  11. Optimization of the output and efficiency of a high power cascaded arc hydrogen plasma source

    SciTech Connect (OSTI)

    Vijvers, W. A. J.; Gils, C. A. J. van; Goedheer, W. J.; Meiden, H. J. van der; Veremiyenko, V. P.; Westerhout, J.; Lopes Cardozo, N. J.; Rooij, G. J. van [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Schram, D. C. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2008-09-15T23:59:59.000Z

    The operation of a cascaded arc hydrogen plasma source was experimentally investigated to provide an empirical basis for the scaling of this source to higher plasma fluxes and efficiencies. The flux and efficiency were determined as a function of the input power, discharge channel diameter, and hydrogen gas flow rate. Measurements of the pressure in the arc channel show that the flow is well described by Poiseuille flow and that the effective heavy particle temperature is approximately 0.8 eV. Interpretation of the measured I-V data in terms of a one-parameter model shows that the plasma production is proportional to the input power, to the square root of the hydrogen flow rate, and is independent of the channel diameter. The observed scaling shows that the dominant power loss mechanism inside the arc channel is one that scales with the effective volume of the plasma in the discharge channel. Measurements on the plasma output with Thomson scattering confirm the linear dependence of the plasma production on the input power. Extrapolation of these results shows that (without a magnetic field) an improvement in the plasma production by a factor of 10 over where it was in van Rooij et al. [Appl. Phys. Lett. 90, 121501 (2007)] should be possible.

  12. Pico- and nanosecond laser ablation of mixed tungsten / aluminium films

    E-Print Network [OSTI]

    Wisse, M; Steiner, R; Mathys, D; Stumpp, A; Joanny, M; Travere, J M; Meyer, E

    2014-01-01T23:59:59.000Z

    In order to extend the investigation of laser-assisted cleaning of ITER-relevant first mirror materials to the picosecond regime, a commercial laser system delivering 10 picosecond pulses at 355 nm at a frequency of up to 1 MHz has been used to investigate the ablation of mixed aluminium (oxide) / tungsten (oxide) layers deposited on poly- and nanocrystalline molybdenum as well as nanocrystalline rhodium mirrors. Characterization before and after cleaning using scanning electron microscopy (SEM) and spectrophotometry shows heavy dust formation, resulting in a degradation of the reflectivity. Cleaning using a 5 nanosecond pulses at 350 and 532 nm, on the other hand, proved very promising. The structure of the film remnants suggests that in this case buckling was the underlying removal mechanism rather than ablation. Repeated coating and cleaning using nanosecond pulses is demonstrated.

  13. Determination of the electron–phonon coupling constant in tungsten

    SciTech Connect (OSTI)

    Daraszewicz, Szymon L.; Duffy, Dorothy M.; Shluger, Alexander L. [Department of Physics and Astronomy, London Centre for Nanotechnology, University College London, Gower Street, WC1E 6BT London (United Kingdom); Giret, Yvelin [Department of Physics and Astronomy, London Centre for Nanotechnology, University College London, Gower Street, WC1E 6BT London (United Kingdom); The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan); Tanimura, Hiroshi; Tanimura, Katsumi [The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan)

    2014-07-14T23:59:59.000Z

    We used two methods to determine the effective electron-phonon coupling constant (G{sub 0}) in tungsten. Our first principles calculations predict G{sub 0}?=?1.65?×?10{sup 17?}W m{sup ?3} K{sup ?1}. The temporal decay of the femtosecond-resolution optical reflectivity for a (100) surface of bulk W was measured using a pump-probe scheme and analysed using ab initio parameterised two temperature model, which includes both the effects of the electron-phonon coupling and thermal conduction into bulk. This analysis gives G{sub 0}?=?1.4(3)?×?10{sup 17?}W m{sup ?3} K{sup ?1}, in good agreement with the theoretical prediction. The described effective method of calculating and measuring G{sub 0} in bulk materials can be easily extended to other metals.

  14. Gamma Spectrum from Neutron Capture on Tungsten Isotopes

    SciTech Connect (OSTI)

    Hurst, Aaron; Summers, Neil; Sleaford, Brad; Firestone, Richard B; Belgya, T.; Revay, Z.S.

    2010-04-29T23:59:59.000Z

    An evaluation of thermal neutron capture on the stable tungsten isotopes is presented, with preliminary results for the compound systems 183;184;185;187W. The evaluation procedure compares the g-ray cross-section data collected at the Budapest reactor, with Monte Carlo simulations of g-ray emission following the thermal neutron-capture process. The statistical-decay code DICEBOX was used for the Monte Carlo simulations. The evaluation yields new gamma rays in 185W and the confirmation of spins in 187W, raising the number of levels below which the level schemes are considered complete, thus increasing the number of levels that can be used in neutron data libraries.

  15. Performance of a Clad Tungsten Rod Spallation Neutron Source Target

    SciTech Connect (OSTI)

    Sommer, Walter F. [Los Alamos National Laboratory (United States); Maloy, Stuart A. [Los Alamos National Laboratory (United States); Louthan, McIntyre R. [Savannah River National Laboratory (United States); Willcutt, Gordon J. [Los Alamos National Laboratory (United States); Ferguson, Phillip D. [Oak Ridge National Laboratory (United States); James, Michael R. [Los Alamos National Laboratory (United States)

    2005-09-15T23:59:59.000Z

    Tungsten rods, slip-clad with Type 304L stainless steel, performed successfully as a spallation neutron source target operating to a peak fluence of {approx}4 x 10{sup 21} p/cm{sup 2}. The target was used as a neutron source during the Accelerator Production of Tritium (APT) materials irradiation program at the Los Alamos Neutron Science Center. Tungsten rods of 2.642-mm diameter were slip-fit in Type 304L stainless steel tubes that had an inner diameter of 2.667 mm. The radial gap was filled with helium at atmospheric pressure and room temperature. Los Alamos High Energy Transport (LAHET) calculations suggest a time-averaged peak power deposition in the W of 2.25 kW/cm{sup 3}. Thermal-hydraulic calculations indicate that the peak centerline W temperature reached 271 deg. C. The LAHET calculations were also used to predict neutron and proton fluxes and spectra for the complex geometry used in the irradiation program. Activation foil sets distributed throughout the experiment were used to determine target neutronics performance as a comparison to the LAHET calculations. Examination of the irradiated target assemblies revealed no significant surface degradation or corrosion on either the Type 304L or the W surfaces. However, it was clear that the irradiation changed material properties because post-proton-irradiation measurements on Type 304L test samples from the APT program demonstrated increases in the yield strength and decreases in the ductility and fracture toughness with increasing dose, and the wrought W rod samples became brittle. Fortunately, the slip-clad target design subjects the materials to very low stress.

  16. Constraints on the composition of the Aleutian arc lower crust from

    E-Print Network [OSTI]

    Shillington, Donna J.

    Determining the bulk composition of island arc lower crust is essential for distinguishing between competing models for arc magmatism and assessing the stability of arc lower crust. We present new constraints on the ...

  17. Tungsten bridge for the low energy ignition of explosive and energetic materials

    DOE Patents [OSTI]

    Benson, D.A.; Bickes, R.W. Jr.; Blewer, R.S.

    1990-12-11T23:59:59.000Z

    A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose. 2 figs.

  18. Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten

    E-Print Network [OSTI]

    Harilal, S. S.

    erosion rate [1]. In addition, tungsten is a high Z material, therefore the physical sputtering yield surface [5­7] or liquid lithium [8] has been recently studied, while others investigated the low energy

  19. Sintering and joining of low temperature co-fired tungsten and aluminum oxide

    E-Print Network [OSTI]

    Boonyongmaneerat, Yuttanant

    2006-01-01T23:59:59.000Z

    Conventional methods used to fabricate co-fired tungsten/alumina composites usually rely on high temperature processing (>1500C). As it would be beneficial or even necessary for some applications to produce such composites ...

  20. Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Chloride as the Acid

    E-Print Network [OSTI]

    Jeong, Hyangsoo

    Routes to new tungsten alkylidene complexes that contain tert-butylimido or adamantylimido ligands have been devised that begin with a reaction between WCl[subscript 6] and 4 equivalents of HNR(TMS) to give [W(NR)[subscript ...

  1. Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2,6-Dimesitylphenylimido Ligand

    E-Print Network [OSTI]

    Gerber, Laura C. H.

    Molybdenum and tungsten bispyrrolide alkylidene complexes that contain a 2,6-dimesitylphenylimido (NAr*) ligand have been prepared, in which the pyrrolide is the parent pyrrolide or 2,5-dimethylpyrrolide. Monoalkoxide ...

  2. Electropolymerized Polyaniline Stabilized Tungsten Oxide Nanocomposite Films: Electrochromic Behavior and Electrochemical

    E-Print Network [OSTI]

    Guo, John Zhanhu

    Electropolymerized Polyaniline Stabilized Tungsten Oxide Nanocomposite Films: Electrochromic. The optical properties and electrochemical capacitive behaviors of the composite films for electrochromic (EC electrochromism at both positive and negative potentials arising from PANI and WO3, respectively. A coloration

  3. Electrochromic properties of tungsten trioxide thin films prepared by photochemical vapor deposition

    SciTech Connect (OSTI)

    Maruyama, Toshiro; Kanagawa, Tetsuya (Kyoto Univ. (Japan). Dept. of Chemical Engineering)

    1994-09-01T23:59:59.000Z

    Electrochromic tungsten trioxide thin films were prepared by a photochemical vapor deposition. The source material was tungsten carbonyl. A 6 W low pressure mercury lamp was used as a light source. Amorphous tungsten trioxide thin films were obtained at a substrate temperature of 200 C. The UV radiation enhances the oxidation of tungsten, in addition to the acceleration of the deposition of the films. Reduction and oxidation of the films in a 0.3M LiClO[sub 4] propylene carbonate solution resulted in desirable changes in optimal absorption. The bleaching time was short compared to the amorphous CVD film. Coulometry indicated that the coloration efficiency was 222 cm[sup 2]/C.

  4. Simulation Studies of Hydrogen Ion reflection from Tungsten for the Surface Production of Negative Hydrogen Ions

    SciTech Connect (OSTI)

    Kenmotsu, Takahiro; Wada, Motoi [Doshisha University, Kyotanabe, Kyoto 610-0394 (Japan)

    2011-09-26T23:59:59.000Z

    The production efficiency of negative ions at tungsten surface by particle reflection has been investigated. Angular distributions and energy spectra of reflected hydrogen ions from tungsten surface are calculated with a Monte Carlo simulation code ACAT. The results obtained with ACAT have indicated that angular distributions of reflected hydrogen ions show narrow distributions for low-energy incidence such as 50 eV, and energy spectra of reflected ions show sharp peaks around 90% of incident energy. These narrow angular distributions and sharp peaks are favorable for the efficient extraction of negative ions from an ion source equipped with tungsten surface as negative ionization converter. The retained hydrogen atoms in tungsten lead to the reduction in extraction efficiency due to boarded angular distributions.

  5. Recent progress in R&D on tungsten alloys for divertor structural and plasma facing materials

    SciTech Connect (OSTI)

    Wurster, S.; Baluc, N.; Battabyal, M.; Crosby, T.; Du, J.; Garcia-Rosales, C.; Hasegawa, Akira; Hoffmann, A.; Kimura, A.; Kurishita, Hiroaki; Kurtz, Richard J.; Li, H.; Noh, S.; Reiser, J.; Riesch, J.; Rieth, Michael; Setyawan, Wahyu; Walter, M.; You, J. H.; Pippan, R.

    2013-03-13T23:59:59.000Z

    Tungsten materials are candidates for plasma facing components for ITER and DEMO because of their superior thermophysical properties. Knowledge and strategies to improve properties of tungsten-based materials are still under development, as they are not a common structural material such as steel. Consequently, several activities have started in Europe, Japan, USA and China. Research is directed towards manufacturing of new materials based on alloying, microstructure stabilizing and composite formation involving improved processing steps. Beside experimental analyses, work also focuses on computational treatment of open questions, supporting the development of better tungsten materials. Assuming the availability of an ideal material that is ready to use, there remain the questions of inherent safety, the joining of tungsten to steel and the influence of radiation damage. These are topics of increasing interest when the material comes to application.

  6. Tungsten bridge for the low energy ignition of explosive and energetic materials

    DOE Patents [OSTI]

    Benson, David A. (Albuquerque, NM); Bickes, Jr., Robert W. (Albuquerque, NM); Blewer, Robert S. (Albuquerque, NM)

    1990-01-01T23:59:59.000Z

    A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose.

  7. Multiphysics Design and Simulation of a Tungsten-Cermet Nuclear Thermal Rocket

    E-Print Network [OSTI]

    Appel, Bradley

    2012-10-19T23:59:59.000Z

    fuel safety have sparked interest in an NTR core based on tungsten-cermet fuel. This work investigates the capability of modern CFD and neutronics codes to design a cermet NTR, and makes specific recommendations for the configuration of channels...

  8. Tantalum-Tungsten Oxide Thermite Composite Prepared by Sol-Gel Synthesis and Spark Plasma Sintering

    SciTech Connect (OSTI)

    Cervantes, O; Kuntz, J; Gash, A; Munir, Z

    2009-02-13T23:59:59.000Z

    Energetic composite powders consisting of sol-gel derived nanostructured tungsten oxide were produced with various amounts of micrometer-scale tantalum fuel metal. Such energetic composite powders were ignition tested and results show that the powders are not sensitive to friction, spark and/or impact ignition. Initial consolidation experiments, using the High Pressure Spark Plasma Sintering (HPSPS) technique, on the sol-gel derived nanostructured tungsten oxide produced samples with higher relative density than can be achieved with commercially available tungsten oxide. The sol-gel derived nanostructured tungsten oxide with immobilized tantalum fuel metal (Ta - WO{sub 3}) energetic composite was consolidated to a density of 9.17 g.cm{sup -3} or 93% relative density. In addition those parts were consolidated without significant pre-reaction of the constituents, thus the sample retained its stored chemical energy.

  9. Greenhouse Gas Reductions: SF6

    ScienceCinema (OSTI)

    Anderson, Diana

    2013-04-19T23:59:59.000Z

    Argonne National Laboratory is leading the way in greenhouse gas reductions, particularly with the recapture and recycling of sulfur hexafluoride (SF6). SF6 is a gas used in industry as an anti-arcing agent. It is an extremely potent greenhouse gas ? one pound of SF6 is equivalent to 12 tons of carbon dioxide. While the U.S. does not currently regulate SF6 emissions, Argonne is proactively and voluntarily recovering and recycling to reduce SF6 emissions. Argonne saves over 16,000 tons of SF6 from being emitted into the atmosphere each year, and by recycling the gas rather than purchasing it new, we save taxpayers over $208,000 each year.

  10. Greenhouse Gas Reductions: SF6

    SciTech Connect (OSTI)

    Anderson, Diana

    2012-01-01T23:59:59.000Z

    Argonne National Laboratory is leading the way in greenhouse gas reductions, particularly with the recapture and recycling of sulfur hexafluoride (SF6). SF6 is a gas used in industry as an anti-arcing agent. It is an extremely potent greenhouse gas — one pound of SF6 is equivalent to 12 tons of carbon dioxide. While the U.S. does not currently regulate SF6 emissions, Argonne is proactively and voluntarily recovering and recycling to reduce SF6 emissions. Argonne saves over 16,000 tons of SF6 from being emitted into the atmosphere each year, and by recycling the gas rather than purchasing it new, we save taxpayers over $208,000 each year.

  11. arc welding automation: Topics by E-print Network

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

    arc welding automation First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Double-Sided Arc Welding...

  12. arc plasma torch: Topics by E-print Network

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

    Summary: periodA, sagitta in dipoles dipSag." arc2Table::usage "arc2Table R,cirC,pA,pL,phA,,, prints a table periodA, sagitta in dipoles dipSag." Begin "Private"...

  13. arc plasma torches: Topics by E-print Network

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

    Summary: periodA, sagitta in dipoles dipSag." arc2Table::usage "arc2Table R,cirC,pA,pL,phA,,, prints a table periodA, sagitta in dipoles dipSag." Begin "Private"...

  14. What makes an electric welding arc perform its required function

    SciTech Connect (OSTI)

    Correy, T.B.

    1982-09-01T23:59:59.000Z

    The physics of direct current and alternating current welding arcs, the heat transfer of direct current welding arcs, the characteristics of dc welding and ac welding power supplies and recommendations for the procurement and maintenance of precision power supplies are discussed. (LCL)

  15. Kinetics of thermal decomposition of molybdenum carbonyl on a tungsten surface

    SciTech Connect (OSTI)

    Baev, A.K.; Podoprigora, V.I. [S.M. Kirov Belorussian Technological Inst., Minsk (Russian Federation)

    1993-04-20T23:59:59.000Z

    Thermal decomposition of Mo(CO){sub 6} on the surface of pyrolytic tungsten is performed under quasi-stationary conditions. The analysis of kinetics shows the reaction to occur in a kinetic region. The activation energy of Mo(CO){sub 6} decomposition on tungsten substrate calculated according to the Arrhenius equation is 63.7 {plus_minus} 3.0 kJ/mole. 4 refs., 1 fig., 1 tab.

  16. E-Print Network 3.0 - arc discharge method Sample Search Results

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

    at different points on the cable. The discharge contained short, bluish arcs. 12... Artificial Dry-band Arcing ... Source: Arizona State University, Power Systems Engineering...

  17. Optical Sensors for Post Combustion Control in Electric Arc Furnace Steelmaking (TRP 9851)

    SciTech Connect (OSTI)

    Sarah W. Allendorf; David K. Ottesen; Robert W. Green; Donald R. Hardesty; Robert Kolarik; Howard Goodfellow; Euan Evenson; Marshall Khan; Ovidiu Negru; Michel Bonin; Soren Jensen

    2003-12-31T23:59:59.000Z

    Working in collaboration with Stantec Global Technologies, Process Metrix Corporation, and The Timken Company, Sandia National Laboratories constructed and evaluated a novel, laser-based off-gas sensor at the electric arc furnace facility of Timken's Faircrest Steel Plant (Canton, Ohio). The sensor is based on a mid-infrared tunable diode laser (TDL), and measures the concentration and temperature of specific gas species present in the off-gas emanating from the EAF. The laser beam is transmitted through the gas stream at the fourth hole of the EAF, and provides a real-time, in situ measurement that can be used for process optimization. Two sets of field tests were performed in parallel with Stantec's extractive probe off-gas system, and the tests confirm the TDL sensor's operation and applicability for electric steel making. The sensor measures real-time, in situ line-of-sight carbon monoxide (CO) concentrations between 5% and 35% CO, and measures off-gas temperature in the range of 1400 to 1900 K. In order to achieve commercial-ready status, future work is required to extend the sensor for simultaneous CO and CO{sub 2} concentration measurements. In addition, long-term endurance tests including process optimization must be completed.

  18. Tungsten coating for improved wear resistance and reliability of microelectromechanical devices

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM); Mani, Seethambal S. (Albuquerque, NM); Sniegowski, Jeffry J. (Edgewood, NM); Blewer, Robert S. (Albuquerque, NM)

    2001-01-01T23:59:59.000Z

    A process is disclosed whereby a 5-50-nanometer-thick conformal tungsten coating can be formed over exposed semiconductor surfaces (e.g. silicon, germanium or silicon carbide) within a microelectromechanical (MEM) device for improved wear resistance and reliability. The tungsten coating is formed after cleaning the semiconductor surfaces to remove any organic material and oxide film from the surface. A final in situ cleaning step is performed by heating a substrate containing the MEM device to a temperature in the range of 200-600 .degree. C. in the presence of gaseous nitrogen trifluoride (NF.sub.3). The tungsten coating can then be formed by a chemical reaction between the semiconductor surfaces and tungsten hexafluoride (WF.sub.6) at an elevated temperature, preferably about 450.degree. C. The tungsten deposition process is self-limiting and covers all exposed semiconductor surfaces including surfaces in close contact. The present invention can be applied to many different types of MEM devices including microrelays, micromirrors and microengines. Additionally, the tungsten wear-resistant coating of the present invention can be used to enhance the hardness, wear resistance, electrical conductivity, optical reflectivity and chemical inertness of one or more semiconductor surfaces within a MEM device.

  19. Growth study and photocatalytic properties of Co-doped tungsten oxide mesocrystals

    SciTech Connect (OSTI)

    Sun, Shibin [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China) [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China); College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China); Chang, Xueting, E-mail: xuetingchang@yahoo.cn [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China)] [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China); Li, Zhenjiang [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China)

    2012-11-15T23:59:59.000Z

    Cobalt-doped tungsten oxide mesocrystals with different morphologies have been successfully generated using a solvothermal method with tungsten hexachloride and cobalt chloride salts as precursors. The resulting mesocrystals were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Brunauer-Emmet-Teller analysis of nitrogen sorptometer, and UV-vis diffuse reflectance spectroscopy. The photocatalytic properties of the cobalt-doped tungsten oxide mesocrystals were evaluated on the basis of their ability to degrade methyl orange in an aqueous solution under simulated sunlight irradiation. Results showed that the cobalt doping had obvious effect on the morphologies of the final products, and lenticular and blocky cobalt-doped tungsten oxide mesocrystals could be obtained with 1.0 wt.% and 2.0 wt.% cobalt doping, respectively. The cobalt-doped tungsten oxides exhibited superior photocatalytic activities to that of the undoped tungsten oxide. - Graphical abstract: Schematic illustrations of the growth of the bundled nanowires, lenticular mesocrystals, and blocky mesocrystals. Highlights: Black-Right-Pointing-Pointer Co-doped W{sub 18}O{sub 49} mesocrystals were synthesized using a solvothermal method. Black-Right-Pointing-Pointer The Co doping has obvious effect on the morphology of the final mesocrystals. Black-Right-Pointing-Pointer The Co-doped W{sub 18}O{sub 49} exhibited superior photocatalytic activity to the undoped W{sub 18}O{sub 49}.

  20. Study on the oxidation and reduction of tungsten surface for sub-50 nm patterning process

    SciTech Connect (OSTI)

    Kim, Jong Kyu; Nam, Seok Woo; Cho, Sung Il; Jhon, Myung S.; Min, Kyung Suk; Kim, Chan Kyu; Jung, Ho Bum; Yeom, Geun Young [Memory Division Semiconductor Business, Samsung Electronics, San No. 16 Banwol-Ri, Taean-Eup, Hwasung-City, Gyeonggi-Do 449-711, South Korea and Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Memory Division Semiconductor Business, Samsung Electronics, San No. 16 Banwol-Ri, Taean-Eup, Hwasung-City, Gyeonggi-Do 449-711 (Korea, Republic of); Department of Chemical Engineering and Data Storage Systems Center, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

    2012-11-15T23:59:59.000Z

    The oxidation characteristics of tungsten line pattern during the carbon-based mask-layer removal process using oxygen plasmas have been investigated for sub-50 nm patterning processes, in addition to the reduction characteristics of the WO{sub x} layer formed on the tungsten line surface using hydrogen plasmas. The surface oxidation of tungsten lines during the mask layer removal process could be minimized by using low-temperature (300 K) plasma processing for the removal of the carbon-based material. Using this technique, the thickness of WO{sub x} on the tungsten line could be decreased to 25% compared to results from high-temperature processing. The WO{sub x} layer could also be completely removed at a low temperature of 300 K using a hydrogen plasma by supplying bias power to the tungsten substrate to provide a activation energy for the reduction. When this oxidation and reduction technique was applied to actual 40-nm-CD device processing, the complete removal of WO{sub x} formed on the sidewall of tungsten line could be observed.

  1. Synthesis and electrochemical capacitance of long tungsten oxide nanorod arrays grown vertically on substrate

    SciTech Connect (OSTI)

    Park, Sun Hwa [Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of)] [Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Kim, Young Heon; Lee, Tae Geol; Shon, Hyun Kyong [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of)] [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Park, Hyun Min [Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of) [Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Song, Jae Yong, E-mail: jysong@kriss.re.kr [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Department of Nano Science, University of Science and Technology, Daejeon 305-350 (Korea, Republic of)

    2012-11-15T23:59:59.000Z

    Highlights: ? Growth of long amorphous tungsten oxide nanorods on a substrate. ? Formation of single-crystalline tungsten oxide nanorods by a heat-treatment. ? High electrochemical pseudocapacitance of 2.8 mF cm{sup ?2}. ? Excellent cyclability of psuedocapacitance up to 1000 cycles. -- Abstract: Long tungsten oxide nanorods are vertically grown on Al/W/Ti coated silicon substrates using a two-step anodization process. The first anodization of the Al film forms a mesh-like mask of anodic aluminum oxide, and the second anodization of the W film results in the formation of a buffer layer, a bottom nanorod, and a top nanorod of amorphous tungsten oxide. A pore-widening process prior to the second anodization leads to the enhancement of nanorod length above approximately 500 nm. After a heat-treatment, the tungsten oxide nanorods are crystallized to form a single crystalline structure while the buffer layer forms a polycrystalline structure. The crystalline tungsten oxide nanorods show a cyclic voltammogram retaining the quasi-rectangular shape of an electrochemically reversible faradaic redox reaction, i.e., a typical pseudocapacitive behavior. The maximum electrochemical capacitance per apparent surface area reaches approximately 2.8 mF cm{sup ?2} at the voltage scan rate of 20 mV s{sup ?1}, and the excellent cyclability of charge–discharge process is maintained up to 1000 cycles.

  2. Enhanced catalyst for converting synthesis gas to liquid motor fuels

    DOE Patents [OSTI]

    Coughlin, Peter K. (Yorktown Heights, NY)

    1986-01-01T23:59:59.000Z

    The conversion of synthesis gas to liquid molar fuels by means of a cobalt Fischer-Tropsch catalyst composition is enhanced by the addition of molybdenum, tungsten or a combination thereof as an additional component of said composition. The presence of the additive component increases the olefinic content of the hydrocarbon products produced. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

  3. B(C6F5)3 Activation of Oxo Tungsten Complexes That Are Relevant to Olefin Metathesis

    E-Print Network [OSTI]

    Müller, Peter

    B(C6F5)3 Activation of Oxo Tungsten Complexes That Are Relevant to Olefin Metathesis Dmitry V Information ABSTRACT: We have found that coordination of B(C6F5)3 to an oxo ligand in tungsten oxo alkylidene reactions between a relatively well behaved Lewis acid (B(C6F5)3) and a variety of tungsten oxo complexes

  4. Method for processing aluminum spent potliner in a graphite electrode arc furnace

    DOE Patents [OSTI]

    O'Connor, William K.; Turner, Paul C.; Addison, G.W. (AJT Enterprises, Inc.)

    2002-12-24T23:59:59.000Z

    A method of processing spent aluminum pot liner containing carbon, cyanide compositions, fluorides and inorganic oxides. The spend aluminum pot liner is crushed, iron oxide is added to form an agglomerated material. The agglomerated material is melted in an electric arc furnace having the electrodes submerged in the molten material to provide a reducing environment during the furnace operation. In the reducing environment, pot liner is oxidized while the iron oxides are reduced to produce iron and a slag substantially free of cyanide compositions and fluorides. An off-gas including carbon oxides and fluorine is treated in an air pollution control system with an afterburner and a scrubber to produce NaF, water and a gas vented to the atmosphere free of cyanide compositions, fluorine, and CO.

  5. Method for processing aluminum spent potliner in a graphite electrode ARC furnace

    DOE Patents [OSTI]

    O'Connor, William K. (Lebanon, OR); Turner, Paul C. (Independence, OR); Addison, Gerald W. (St. Stephen, SC)

    2002-12-24T23:59:59.000Z

    A method of processing spent aluminum pot liner containing carbon, cyanide compositions, fluorides and inorganic oxides. The spent aluminum pot liner is crushed iron oxide is added to form an agglomerated material. The agglomerated material is melted in an electric arc furnace having the electrodes submerged in the molten material to provide a reducing environment during the furnace operation. In the reducing environment, pot liner is oxidized while the iron oxides are reduced to produce iron and a slag substantially free of cyanide compositions and fluorides. An off-gas including carbon oxides and fluorine is treated in an air pollution control system with an afterburner and a scrubber to produce NaF, water and a gas vented to the atmosphere free of cyanide compositions, fluorine and CO.

  6. Development of an electron-temperature-dependent interatomic potential for molecular dynamics simulation of tungsten under electronic excitation

    E-Print Network [OSTI]

    Alfè, Dario

    simulation of tungsten under electronic excitation S. Khakshouri,1,* D. Alfè,1,2 and D. M. Duffy1,3 1

  7. Magnetization curves of sintered heavy tungsten alloys for applications in MRI-guided radiotherapy

    SciTech Connect (OSTI)

    Kolling, Stefan [Sydney Medical School, University of Sydney, NSW 2006 (Australia)] [Sydney Medical School, University of Sydney, NSW 2006 (Australia); Oborn, Bradley M. [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia)] [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Keall, Paul J., E-mail: paul.keall@sydney.edu.au [Sydney Medical School, University of Sydney, NSW 2006, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); Horvat, Joseph [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2500, Australia and School of Physics, University of Wollongong, Wollongong, NSW 2500 (Australia)] [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2500, Australia and School of Physics, University of Wollongong, Wollongong, NSW 2500 (Australia)

    2014-06-15T23:59:59.000Z

    Purpose: Due to the current interest in MRI-guided radiotherapy, the magnetic properties of the materials commonly used in radiotherapy are becoming increasingly important. In this paper, measurement results for the magnetization (BH) curves of a range of sintered heavy tungsten alloys used in radiation shielding and collimation are presented. Methods: Sintered heavy tungsten alloys typically contain >90?% tungsten and <10?% of a combination of iron, nickel, and copper binders. Samples of eight different grades of sintered heavy tungsten alloys with varying binder content were investigated. Using a superconducting quantum interference detector magnetometer, the induced magnetic momentm was measured for each sample as a function of applied external field H{sub 0} and the BH curve derived. Results: The iron content of the alloys was found to play a dominant role, directly influencing the magnetizationM and thus the nonlinearity of the BH curve. Generally, the saturation magnetization increased with increasing iron content of the alloy. Furthermore, no measurable magnetization was found for all alloys without iron content, despite containing up to 6% of nickel. For two samples from different manufacturers but with identical quoted nominal elemental composition (95% W, 3.5% Ni, 1.5% Fe), a relative difference in the magnetization of 11%–16% was measured. Conclusions: The measured curves show that the magnetic properties of sintered heavy tungsten alloys strongly depend on the iron content, whereas the addition of nickel in the absence of iron led to no measurable effect. Since a difference in the BH curves for two samples with identical quoted nominal composition from different manufacturers was observed, measuring of the BH curve for each individual batch of heavy tungsten alloys is advisable whenever accurate knowledge of the magnetic properties is crucial. The obtained BH curves can be used in FEM simulations to predict the magnetic impact of sintered heavy tungsten alloys.

  8. Tungsten carbide synthesized by low-temperature combustion as gas diffusion electrode catalyst

    E-Print Network [OSTI]

    Volinsky, Alex A.

    of Science and Technology Beijing, Beijing 100083, China b Departament Fi´sica Aplicada, EETAC, Universitat Polite`cnica de Catalunya e BarcelonaTech, 08860 Castelldefels, Spain c Department of Metallurgical performance, comparable with that of Pt. Copyright ª 2014, Hydrogen Energy Publications, LLC. Published

  9. Acoustic stabilization of electric arc instabilities in nontransferred plasma torches

    SciTech Connect (OSTI)

    Rat, V.; Coudert, J. F. [CNRS, University of Limoges, SPTCS UMR6638, 123 Avenue A. Thomas, 87060 Limoges Cedex (France)

    2010-03-08T23:59:59.000Z

    Electric arc instabilities in dc plasma torches lead to nonhomogeneous treatments of nanosized solid particles or liquids injected within thermal plasma jets. This paper shows that an additional acoustic resonator mounted on the cathode cavity allows reaching a significant damping of these instabilities, particularly the Helmholtz mode of arc oscillations. The acoustic resonator is coupled with the Helmholtz resonator of the plasma torch limiting the amplitude of arc voltage variations. It is also highlighted that this damping is dependent on friction effects in the acoustic resonator.

  10. Spectroscopic constants and potential energy curves of tungsten carbide

    SciTech Connect (OSTI)

    Balasubramanian, K. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)

    2000-05-01T23:59:59.000Z

    Spectroscopic constants (R{sub e},{omega}{sub e},T{sub e},{mu}{sub e}) and potential energy curves for 40 low-lying electronic states of the diatomic tungsten carbide (WC) were obtained using the complete active space multiconfiguration self-consistent field followed by the multireference singles+doubles configuration interaction and full first- and second-order configuration interaction calculations that included up to 6.4 mil configurations. Spin-orbit effects were included through the enhanced relativistic configuration interaction method described here for 28 electronic states of WC lying below {approx}20 000 cm-1. The spin-orbit splitting of the ground state of WC was found to be very large (4394 cm-1). The ground and excited electronic states of the W atom were also computed and were found to be in good agreement with the experimental data. The nature of bonding was analyzed through the composition of orbitals, leading configurations, Mulliken populations, and dipole moments. The dissociation energy of WC was computed including spin-orbit and electron correlation effects. The recent photoelectron spectra of WC{sup -} were assigned on the basis of our computed results. (c) 2000 American Institute of Physics.

  11. Activation Energy of Tantalum-Tungsten Oxide Thermite Reaction

    SciTech Connect (OSTI)

    Cervantes, O; Kuntz, J; Gash, A; Munir, Z

    2010-02-25T23:59:59.000Z

    The activation energy of a high melting temperature sol-gel (SG) derived tantalum-tungsten oxide thermite composite was determined using the Kissinger isoconversion method. The SG derived powder was consolidated using the High Pressure Spark Plasma Sintering (HPSPS) technique to 300 and 400 C to produce pellets with dimensions of 5 mm diameter by 1.5 mm height. A custom built ignition setup was developed to measure ignition temperatures at high heating rates (500-2000 C {center_dot} min{sup -1}). Such heating rates were required in order to ignite the thermite composite. Unlike the 400 C samples, results show that the samples consolidated to 300 C undergo an abrupt change in temperature response prior to ignition. This change in temperature response has been attributed to the crystallization of the amorphous WO{sub 3} in the SG derived Ta-WO{sub 3} thermite composite and not to a pre-ignition reaction between the constituents. Ignition temperatures for the Ta-WO{sub 3} thermite ranged from approximately 465-670 C. The activation energy of the SG derived Ta-WO{sup 3} thermite composite consolidated to 300 and 400 C were determined to be 37.787 {+-} 1.58 kJ {center_dot} mol{sup -1} and 57.381 {+-} 2.26 kJ {center_dot} mol{sup -1}, respectively.

  12. DISPLACEMENT CASCADE SIMULATION IN TUNGSTEN AT 1025 K

    SciTech Connect (OSTI)

    Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.; Heinisch, Howard L.; Kurtz, Richard J.; Wirth, Brian D.

    2013-09-30T23:59:59.000Z

    Molecular dynamics simulation was employed to investigate the irradiation damage properties of bulk tungsten at 1025 K (0.25 melting temperature). A comprehensive data set of primary cascade damage was generated up to primary knock-on atom (PKA) energies 100 keV. The dependence of the number of surviving Frenkel pairs (NFP) on the PKA energy (E) exhibits three different characteristic domains presumably related to the different cascade morphologies that form. The low-energy regime < 0.2 keV is characterized by a hit-or-miss type of Frenkel pair (FP) production near the displacement threshold energy of 128 eV. The middle regime 0.3 – 30 keV exhibits a sublinear dependence of log(NFP) vs log(E) associated with compact cascade morphology with a slope of 0.73. Above 30 keV, the cascade morphology consists of complex branches or interconnected damage regions. In this extended morphology, large interstitial clusters form from superposition of interstitials from nearby damage regions. Strong clustering above 30 keV results in a superlinear dependence of log(NFP) vs log(E) with a slope of 1.365. At 100 keV, an interstitial cluster of size 92 and a vacancy cluster of size 114 were observed.

  13. 2566 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 Quantitative Analysis of Gas Circuit Breaker

    E-Print Network [OSTI]

    Basse, Nils Plesner

    --Understanding the dynamic processes governing gas circuit breaker physics is crucial in order to continue to improve short, especially those induced at flow reversal where the gas flow between the arc zone and heating volume changes2566 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 Quantitative Analysis of Gas

  14. Column generation heuristic for a rich arc routing Application to railroad track inspection routing

    E-Print Network [OSTI]

    Ingrand, François

    /LAAS) Optimising maintenance routing ATMOS 2010 7 / 24 #12;Literature review Industrial arc routing problems Hasle

  15. FusionArc optimization: A hybrid volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) planning strategy

    SciTech Connect (OSTI)

    Matuszak, Martha M.; McShan, Daniel L.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Steers, Jennifer M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 and Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Long, Troy; Edwin Romeijn, H. [Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Fraass, Benedick A. [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California 90048 (United States)

    2013-07-15T23:59:59.000Z

    Purpose: To introduce a hybrid volumetric modulated arc therapy/intensity modulated radiation therapy (VMAT/IMRT) optimization strategy called FusionArc that combines the delivery efficiency of single-arc VMAT with the potentially desirable intensity modulation possible with IMRT.Methods: A beamlet-based inverse planning system was enhanced to combine the advantages of VMAT and IMRT into one comprehensive technique. In the hybrid strategy, baseline single-arc VMAT plans are optimized and then the current cost function gradients with respect to the beamlets are used to define a metric for predicting which beam angles would benefit from further intensity modulation. Beams with the highest metric values (called the gradient factor) are converted from VMAT apertures to IMRT fluence, and the optimization proceeds with the mixed variable set until convergence or until additional beams are selected for conversion. One phantom and two clinical cases were used to validate the gradient factor and characterize the FusionArc strategy. Comparisons were made between standard IMRT, single-arc VMAT, and FusionArc plans with one to five IMRT/hybrid beams.Results: The gradient factor was found to be highly predictive of the VMAT angles that would benefit plan quality the most from beam modulation. Over the three cases studied, a FusionArc plan with three converted beams achieved superior dosimetric quality with reductions in final cost ranging from 26.4% to 48.1% compared to single-arc VMAT. Additionally, the three beam FusionArc plans required 22.4%-43.7% fewer MU/Gy than a seven beam IMRT plan. While the FusionArc plans with five converted beams offer larger reductions in final cost-32.9%-55.2% compared to single-arc VMAT-the decrease in MU/Gy compared to IMRT was noticeably smaller at 12.2%-18.5%, when compared to IMRT.Conclusions: A hybrid VMAT/IMRT strategy was implemented to find a high quality compromise between gantry-angle and intensity-based degrees of freedom. This optimization method will allow patients to be simultaneously planned for dosimetric quality and delivery efficiency without switching between delivery techniques. Example phantom and clinical cases suggest that the conversion of only three VMAT segments to modulated beams may result in a good combination of quality and efficiency.

  16. In vivo corrosion, tumor outcome, and microarray gene expression for two types of muscle-implanted tungsten alloys

    SciTech Connect (OSTI)

    Schuster, B.E. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, B434 Mulberry Road, Aberdeen Proving Ground, MD 21005-5609 (United States)] [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, B434 Mulberry Road, Aberdeen Proving Ground, MD 21005-5609 (United States); Roszell, L.E. [U.S. Army Institute of Public Health, 5158 Blackhawk Road, Aberdeen Proving Ground, MD 21010?5403 (United States)] [U.S. Army Institute of Public Health, 5158 Blackhawk Road, Aberdeen Proving Ground, MD 21010?5403 (United States); Murr, L.E.; Ramirez, D.A. [Department of Metallurgical and Materials Engineering, University of Texas, El Paso, TX 79968 (United States)] [Department of Metallurgical and Materials Engineering, University of Texas, El Paso, TX 79968 (United States); Demaree, J.D. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, B434 Mulberry Road, Aberdeen Proving Ground, MD 21005-5609 (United States)] [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, B434 Mulberry Road, Aberdeen Proving Ground, MD 21005-5609 (United States); Klotz, B.R. [Dynamic Science Inc., Aberdeen Proving Ground, MD 21005?5609 (United States)] [Dynamic Science Inc., Aberdeen Proving Ground, MD 21005?5609 (United States); Rosencrance, A.B.; Dennis, W.E. [U.S. Army Center for Environmental Health Research, Department of Chemistry, Ft. Detrick, MD 21702?5010 (United States)] [U.S. Army Center for Environmental Health Research, Department of Chemistry, Ft. Detrick, MD 21702?5010 (United States); Bao, W. [SAS Institute, Inc. SAS Campus Drive, Cary, NC 27513 (United States)] [SAS Institute, Inc. SAS Campus Drive, Cary, NC 27513 (United States); Perkins, E.J. [U.S. Army Engineer Research and Development Center, 3909 Hall Ferry Road, Vicksburg MS 39180 (United States)] [U.S. Army Engineer Research and Development Center, 3909 Hall Ferry Road, Vicksburg MS 39180 (United States); Dillman, J.F. [U.S. Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010?5400 (United States)] [U.S. Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010?5400 (United States); Bannon, D.I., E-mail: desmond.bannon@us.army.mil [U.S. Army Institute of Public Health, 5158 Blackhawk Road, Aberdeen Proving Ground, MD 21010?5403 (United States)

    2012-11-15T23:59:59.000Z

    Tungsten alloys are composed of tungsten microparticles embedded in a solid matrix of transition metals such as nickel, cobalt, or iron. To understand the toxicology of these alloys, male F344 rats were intramuscularly implanted with pellets of tungsten/nickel/cobalt, tungsten/nickel/iron, or pure tungsten, with tantalum pellets as a negative control. Between 6 and 12 months, aggressive rhabdomyosarcomas formed around tungsten/nickel/cobalt pellets, while those of tungsten/nickel/iron or pure tungsten did not cause cancers. Electron microscopy showed a progressive corrosion of the matrix phase of tungsten/nickel/cobalt pellets over 6 months, accompanied by high urinary concentrations of nickel and cobalt. In contrast, non-carcinogenic tungsten/nickel/iron pellets were minimally corroded and urinary metals were low; these pellets having developed a surface oxide layer in vivo that may have restricted the mobilization of carcinogenic nickel. Microarray analysis of tumors revealed large changes in gene expression compared with normal muscle, with biological processes involving the cell cycle significantly up?regulated and those involved with muscle development and differentiation significantly down?regulated. Top KEGG pathways disrupted were adherens junction, p53 signaling, and the cell cycle. Chromosomal enrichment analysis of genes showed a highly significant impact at cytoband 7q22 (chromosome 7) which included mouse double minute (MDM2) and cyclin?dependant kinase (CDK4) as well as other genes associated with human sarcomas. In conclusion, the tumorigenic potential of implanted tungsten alloys is related to mobilization of carcinogenic metals nickel and cobalt from corroding pellets, while gene expression changes in the consequent tumors are similar to radiation induced animal sarcomas as well as sporadic human sarcomas. -- Highlights: ? Tungsten/nickel/cobalt, tungsten/nickel/iron, and pure tungsten were studied. ? Male Fischer rats implanted with pellets in gastrocnemius muscle of each hind leg. ? Aggressive rhabdomyosarcomas developed from tungsten/nickel/cobalt pellets only. ? Microarray gene expression analysis was carried out on selected tumors. ? Pellet degradation, urinary metal concentration, and sarcoma were correlated.

  17. In vitro profiling of epigenetic modifications underlying heavy metal toxicity of tungsten-alloy and its components

    SciTech Connect (OSTI)

    Verma, Ranjana, E-mail: Ranjana.Verma.CTR@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Xu, Xiufen, E-mail: Xiufen.Xu.CTR@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Jaiswal, Manoj K., E-mail: Manoj.Jaiswal.CTR@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Olsen, Cara, E-mail: colsen@usuhs.mil [Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Mears, David, E-mail: dmears@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Caretti, Giuseppina, E-mail: giuseppina.caretti@unimi.it [Department of Biomolecular Sciences and Biotechnology, University of Milan (Italy); Galdzicki, Zygmunt, E-mail: zgaldzicki@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States)

    2011-06-15T23:59:59.000Z

    Tungsten-alloy has carcinogenic potential as demonstrated by cancer development in rats with intramuscular implanted tungsten-alloy pellets. This suggests a potential involvement of epigenetic events previously implicated as environmental triggers of cancer. Here, we tested metal induced cytotoxicity and epigenetic modifications including H3 acetylation, H3-Ser10 phosphorylation and H3-K4 trimethylation. We exposed human embryonic kidney (HEK293), human neuroepithelioma (SKNMC), and mouse myoblast (C2C12) cultures for 1-day and hippocampal primary neuronal cultures for 1-week to 50-200 {mu}g/ml of tungsten-alloy (91% tungsten/6% nickel/3% cobalt), tungsten, nickel, and cobalt. We also examined the potential role of intracellular calcium in metal mediated histone modifications by addition of calcium channel blockers/chelators to the metal solutions. Tungsten and its alloy showed cytotoxicity at concentrations > 50 {mu}g/ml, while we found significant toxicity with cobalt and nickel for most tested concentrations. Diverse cell-specific toxic effects were observed, with C2C12 being relatively resistant to tungsten-alloy mediated toxic impact. Tungsten-alloy, but not tungsten, caused almost complete dephosphorylation of H3-Ser10 in C2C12 and hippocampal primary neuronal cultures with H3-hypoacetylation in C2C12. Dramatic H3-Ser10 dephosphorylation was found in all cobalt treated cultures with a decrease in H3 pan-acetylation in C2C12, SKNMC and HEK293. Trimethylation of H3-K4 was not affected. Both tungsten-alloy and cobalt mediated H3-Ser10 dephosphorylation were reversed with BAPTA-AM, highlighting the role of intracellular calcium, confirmed with 2-photon calcium imaging. In summary, our results for the first time reveal epigenetic modifications triggered by tungsten-alloy exposure in C2C12 and hippocampal primary neuronal cultures suggesting the underlying synergistic effects of tungsten, nickel and cobalt mediated by changes in intracellular calcium homeostasis and buffering. - Highlights: > Tungsten-alloy caused H3-Ser10 dephosphorylation in C2C12 and hippocampal primary cultures. > Dramatic H3-Ser10 dephosphorylation was found in all cobalt treated cultures. > C2C12 cultures exposed to tungsten-alloy or cobalt exhibited decrease in H3 pan-acetylation. > Tungsten-alloy and cobalt mediated H3-Ser10 dephosphorylation was reversed with BAPTA-AM. > These epigenetic modifications were mediated by changes in calcium homeostasis and buffering.

  18. Effect of interfacial interactions on the thermal conductivity and interfacial thermal conductance in tungsten–graphene layered structure

    SciTech Connect (OSTI)

    Jagannadham, K., E-mail: jag-kasichainula@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-09-01T23:59:59.000Z

    Graphene film was deposited by microwave plasma assisted deposition on polished oxygen free high conductivity copper foils. Tungsten–graphene layered film was formed by deposition of tungsten film by magnetron sputtering on the graphene covered copper foils. Tungsten film was also deposited directly on copper foil without graphene as the intermediate film. The tungsten–graphene–copper samples were heated at different temperatures up to 900?°C in argon atmosphere to form an interfacial tungsten carbide film. Tungsten film deposited on thicker graphene platelets dispersed on silicon wafer was also heated at 900?°C to identify the formation of tungsten carbide film by reaction of tungsten with graphene platelets. The films were characterized by scanning electron microscopy, Raman spectroscopy, and x-ray diffraction. It was found that tungsten carbide film formed at the interface upon heating only above 650?°C. Transient thermoreflectance signal from the tungsten film surface on the samples was collected and modeled using one-dimensional heat equation. The experimental and modeled results showed that the presence of graphene at the interface reduced the cross-plane effective thermal conductivity and the interfacial thermal conductance of the layer structure. Heating at 650 and 900?°C in argon further reduced the cross-plane thermal conductivity and interface thermal conductance as a result of formation nanocrystalline tungsten carbide at the interface leading to separation and formation of voids. The present results emphasize that interfacial interactions between graphene and carbide forming bcc and hcp elements will reduce the cross-plane effective thermal conductivity in composites.

  19. automatic arc welding: Topics by E-print Network

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

    control computer, has been accomplished. n.n. 2 Double-Sided Arc Welding Increases Weld Joint Penetration CiteSeer Summary: this paper proposes increasing the penetration by...

  20. arc discharge lamp: Topics by E-print Network

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

    TR, were determined. It was found that there is no local LTE in this arc discharge air plasma during its spacetime evolution, and effects of strong non-izothermality have a...

  1. Kernels for Feedback Arc Set In Tournaments Stephane Bessy

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Kernels for Feedback Arc Set In Tournaments St´ephane Bessy Fedor V. Fomin Serge Gaspers Christophe´e de Montpellier 2, CNRS, 161 rue Ada, 34392 Montpellier, France. {bessy

  2. arc heater production: Topics by E-print Network

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

    the use of this type of product in order to reduce climate emissions. Key words: heat pump water heater, natural refrigerant, CO2, COP 1. unknown authors 35 Circular-Arc...

  3. arc plasma method: Topics by E-print Network

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

    for two types of plasma sources used cathodic-arc plasma source show the coupling efficiency of the plasma flow from the source to the drift Gilson, Erik 8 Computational study...

  4. Properties of tungsten oxide thin films formed by ion-plasma and laser deposition methods for MOSiC-based hydrogen sensors

    SciTech Connect (OSTI)

    Fominski, V. Y., E-mail: vyfominskij@mephi.ru [National Research Nuclear University 'MEPhI' (Russian Federation); Grigoriev, S. N. [Moscow State Technological University 'Stankin' (Russian Federation); Romanov, R. I.; Zuev, V. V.; Grigoriev, V. V. [National Research Nuclear University 'MEPhI' (Russian Federation)

    2012-03-15T23:59:59.000Z

    Thin-film structures based on gas-sensitive tungsten oxide and catalytic platinum are fabricated by room-temperature deposition on a silicon carbide wafer using pulsed laser and ion-plasma methods. Oxide layer annealing in air to 600 Degree-Sign C caused the formation of microstructured and nanostructured crystalline states depending on the deposition conditions. Structural differences affect the electrical parameters and the stability of characteristics. The maximum response to hydrogen is detected in the structure fabricated by depositing a low-energy laser-induced flow of tungsten atoms in oxygen. The voltage shift of the currentvoltage curves for 2% H{sub 2} in air at 350 Degree-Sign C was 4.6 V at a current of {approx}10 {mu}A. The grown structures' metastability caused a significant decrease in the shift after long-term cyclic testing. The most stable shifts of {approx}2 V at positive bias on the Pt contact were detected for oxide films deposited by ion-plasma sputtering.

  5. Role of substrate temperature at graphene synthesis in arc discharge

    E-Print Network [OSTI]

    Fang, Xiuqi; Keidar, Michael

    2015-01-01T23:59:59.000Z

    Substrate temperature required for synthesis of graphene in arc discharge plasma was studied. It was shown that increase of the copper substrate temperature up to melting point leads to increase in the amount of graphene production and quality of graphene sheets. Favorable range of substrate temperatures for arc-based graphene synthesis was determined in relatively narrow range of about 1340-1360K which is near the melting point of copper.

  6. Tunable, self-powered integrated arc plasma-melter vitrification system for waste treatment and resource recovery

    DOE Patents [OSTI]

    Titus, Charles H. (Newtown Square, PA); Cohn, Daniel R. (Chestnuthill, MA); Surma, Jeffrey E. (Kennewick, WA)

    1998-01-01T23:59:59.000Z

    The present invention provides a relatively compact self-powered, tunable waste conversion system and apparatus which has the advantage of highly robust operation which provides complete or substantially complete conversion of a wide range of waste streams into useful gas and a stable, nonleachable solid product at a single location with greatly reduced air pollution to meet air quality standards. The system provides the capability for highly efficient conversion of waste into high quality combustible gas and for high efficiency conversion of the gas into electricity by utilizing a high efficiency gas turbine or by an internal combustion engine. The solid product can be suitable for various commercial applications. Alternatively, the solid product stream, which is a safe, stable material, may be disposed of without special considerations as hazardous material. In the preferred embodiment of the invention, the arc plasma furnace and joule heated melter are formed as a fully integrated unit with a common melt pool having circuit arrangements for the simultaneous independently controllable operation of both the arc plasma and the joule heated portions of the unit without interference with one another. The preferred configuration of this embodiment of the invention utilizes two arc plasma electrodes with an elongated chamber for the molten pool such that the molten pool is capable of providing conducting paths between electrodes. The apparatus may additionally be employed with reduced or without further use of the gases generated by the conversion process. The apparatus may be employed as a self-powered or net electricity producing unit where use of an auxiliary fuel provides the required level of electricity production.

  7. Arc-Fault Detector Algorithm Evaluation Method Utilizing Prerecorded Arcing Signatures

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational Management » History »Dept ofY-12ArahArc

  8. Recycling of electric-arc-furnace dust

    SciTech Connect (OSTI)

    Sresty, G.C.

    1990-05-01T23:59:59.000Z

    Electric arc furnace (EAF) dust is one of the largest solid waste streams produced by steel mills, and is classified as a waste under the Resource Conservation and Recovery Act (RCRA) by the U.S. Environmental Protection Agency (EPA). Successful recycle of the valuable metals (iron, zinc, and lead) present in the dust will result in resource conservation while simultaneously reducing the disposal problems. Technical feasibility of a novel recycling method based on using hydrogen as the reductant was established under this project through laboratory experiments. Sponge iron produced was low in zinc, cadmium, and lead to permit its recycle, and nontoxic to permit its safe disposal as an alternative to recycling. Zinc oxide was analyzed to contain 50% to 58% zinc by weight, and can be marketed for recovering zinc and lead. A prototype system was designed to process 2.5 tons per day (600 tons/year) of EAF dust, and a preliminary economic analysis was conducted. The cost of processing dust by this recycling method was estimated to be comparable to or lower than existing methods, even at such low capacities.

  9. ARCS Additional FirstYear PhD Student Award The Atlanta chapter of ARCS has just informed me that they will honor us with another graduate student

    E-Print Network [OSTI]

    Arnold, Jonathan

    ARCS Additional FirstYear PhD Student Award The Atlanta chapter of ARCS has just informed me meets their definition listed above. Sincerely, Harry A. Dailey, Ph.D. Professor and Director

  10. Evolution of sputtered tungsten coatings at high temperature

    SciTech Connect (OSTI)

    Stelmakh, Veronika; Rinnerbauer, Veronika; Joannopoulos, John D.; Solja?i?, Marin; Celanovic, Ivan; Senkevich, Jay J. [Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Tucker, Charles; Ives, Thomas; Shrader, Ronney [Materion Corporation, Buellton, California 93427 (United States)] [Materion Corporation, Buellton, California 93427 (United States)

    2013-11-15T23:59:59.000Z

    Sputtered tungsten (W) coatings were investigated as potential high temperature nanophotonic material to replace bulk refractory metal substrates. Of particular interest are materials and coatings for thermophotovoltaic high-temperature energy conversion applications. For such applications, high reflectance of the substrate in the infrared wavelength range is critical in order to reduce losses due to waste heat. Therefore, the reflectance of the sputtered W coatings was characterized and compared at different temperatures. In addition, the microstructural evolution of sputtered W coatings (1 and 5 ?m thick) was investigated as a function of anneal temperature from room temperature to 1000 °C. Using in situ x-ray diffraction analysis, the microstrain in the two samples was quantified, ranging from 0.33% to 0.18% for the 1 ?m sample and 0.26% to 0.20% for the 5 ?m sample, decreasing as the temperature increased. The grain growth could not be as clearly quantified due to the dominating presence of microstrain in both samples but was in the order of 20 to 80 nm for the 1 ?m sample and 50 to 100 nm for the 5 ?m sample, as deposited. Finally, the 5 ?m thick layer was found to be rougher than the 1 ?m thick layer, with a lower reflectance at all wavelengths. However, after annealing the 5 ?m sample at 900 °C for 1 h, its reflectance exceeded that of the 1 ?m sample and approached that of bulk W found in literature. Overall, the results of this study suggest that thick coatings are a promising alternative to bulk substrates as a low cost, easily integrated platform for nanostructured devices for high-temperature applications, if the problem of delamination at high temperature can be overcome.

  11. Above: Power deposition in the superconducting magnets and the tungsten-carbide + water shield inside them, according to a

    E-Print Network [OSTI]

    McDonald, Kirk

    Above: Power deposition in the superconducting magnets and the tungsten-carbide + water shield FOR A MUON COLLIDER (TUP265, PAC11) The concept for a muon-production system for a muon collider (or neutrino Magnet shield WC beads + water Shield must dissipate 2.4 MW Superconducting magnets tungsten-carbide (WC

  12. Microstructure of laser-fired, sol-gel-derived tungsten oxide films

    SciTech Connect (OSTI)

    Taylor, D.J.; Birnie, D.P. III [Univ. of Arizona, Tucson, AZ (United States)] [Univ. of Arizona, Tucson, AZ (United States); Cronin, J.P. [Donnelly Corp., Tucson, AZ (United States)] [Donnelly Corp., Tucson, AZ (United States); Allard, L.F. Jr. [Oak Ridge National Lab, TN (United States)] [Oak Ridge National Lab, TN (United States)

    1996-07-01T23:59:59.000Z

    Half-micron-thick tungsten oxide films were deposited by the sol-gel method onto indium tin oxide (ITO) coated soda lime silicate substrates. Following a 100 {degrees}C prebake, the samples were fired with a carbon dioxide laser at a variety of power densities and translation speeds. The laser-fired tungsten oxide films were characterized by spectrophotometry, electrochemistry, multiangle ellipsometry, and transmission electron microscopy and compared to similar furnace-fired films. The data showed an increase in electrochromic response with increased firing temperature up to the point where crystallization of the tungsten oxide retarded electrochromic response. A window with graded electrochromic properties was made by laser firing. 35 refs., 8 figs., 1 tab.

  13. Micro-Raman and cathodoluminescence studies of epitaxial laterally overgrown GaN with tungsten masks: A method to map the free-carrier

    E-Print Network [OSTI]

    Nabben, Reinhard

    Micro-Raman and cathodoluminescence studies of epitaxial laterally overgrown GaN with tungsten properties of two epitaxial-laterally overgrown GaN structures with tungsten masks in 1100 and 1120 direction by tungsten masks3 to prevent the in-diffusion of silicon and oxygen atoms in the overgrown GaN, which

  14. A Tungsten(VI) Nitride Having a W2(-N)2 Core Zachary J. Tonzetich, Richard R. Schrock,* Keith M. Wampler, Brad C. Bailey,

    E-Print Network [OSTI]

    Müller, Peter

    A Tungsten(VI) Nitride Having a W2(µ-N)2 Core Zachary J. Tonzetich, Richard R. Schrock,* Keith M-331, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Received September 27, 2007 The tungsten that the tungsten alkylidyne species W(C-t-Bu)(CH2-t-Bu)(OAr)2 (Ar ) 2,6-diisopropylphenyl) can be prepared readily

  15. Deuterium Depth Profile in Neutron-Irradiated Tungsten Exposed to Plasma

    SciTech Connect (OSTI)

    Masashi Shimada; G. Cao; Y. Hatano; T. Oda; Y. Oya; M. Hara; P. Calderoni

    2011-05-01T23:59:59.000Z

    The effect of radiation damage has been mainly simulated using high-energy ion bombardment. The ions, however, are limited in range to only a few microns into the surface. Hence, some uncertainty remains about the increase of trapping at radiation damage produced by 14 MeV fusion neutrons, which penetrate much farther into the bulk material. With the Japan-US joint research project: Tritium, Irradiations, and Thermofluids for America and Nippon (TITAN), the tungsten samples (99.99 % pure from A.L.M.T., 6mm in diameter, 0.2mm in thickness) were irradiated to high flux neutrons at 50 C and to 0.025 dpa in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). Subsequently, the neutron-irradiated tungsten samples were exposed to a high-flux deuterium plasma (ion flux: 1021-1022 m-2s-1, ion fluence: 1025-1026 m-2) in the Tritium Plasma Experiment (TPE) at the Idaho National Laboratory (INL). First results of deuterium retention in neutron-irradiated tungsten exposed in TPE have been reported previously. This paper presents the latest results in our on-going work of deuterium depth profiling in neutron-irradiated tungsten via nuclear reaction analysis. The experimental data is compared with the result from non neutron-irradiated tungsten, and is analyzed with the Tritium Migration Analysis Program (TMAP) to elucidate the hydrogen isotope behavior such as retention and depth distribution in neutron-irradiated and non neutron-irradiated tungsten.

  16. Effect of silver incorporation in phase formation and band gap tuning of tungsten oxide thin films

    SciTech Connect (OSTI)

    Jolly Bose, R.; Kumar, R. Vinod; Sudheer, S. K.; Mahadevan Pillai, V. P. [Department of Optoelectronics, University of Kerala, Kariyavattom, Thiruvananthapuram, Kerala 695581 (India); Reddy, V. R.; Ganesan, V. [UGC - DAE Consortium for Scientific Research, Khandwa Road, Indore 452017, Madhyapradesh (India)

    2012-12-01T23:59:59.000Z

    Silver incorporated tungsten oxide thin films are prepared by RF magnetron sputtering technique. The effect of silver incorporation in micro structure evolution, phase enhancement, band gap tuning and other optical properties are investigated using techniques such as x-ray diffraction, micro-Raman spectroscopy, atomic force microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and UV-Visible spectroscopy. Effect of silver addition in phase formation and band gap tuning of tungsten oxide thin films are investigated. It is found that the texturing and phase formation improves with enhancement in silver content. It is also found that as the silver incorporation enhances the thickness of the films increases at the same time the strain in the film decreases. Even without annealing the desired phase can be achieved by doping with silver. A broad band centered at the wavelength 437 nm is observed in the absorption spectra of tungsten oxide films of higher silver incorporation and this can be attributed to surface plasmon resonance of silver atoms present in the tungsten oxide matrix. The transmittance of the films is decreased with increase in silver content which can be due to increase in film thickness, enhancement of scattering, and absorption of light caused by the increase of grain size, surface roughness and porosity of films and enhanced absorption due to surface plasmon resonance of silver. It is found that silver can act as the seed for the growth of tungsten oxide grains and found that the grain size increases with silver content which in turn decreases the band gap of tungsten oxide from 3.14 eV to 2.70 eV.

  17. Comparison of Deuterium Retention for Ion-irradiated and Neutron-irradiated Tungsten

    SciTech Connect (OSTI)

    Yasuhisa Oya; Masashi Shimada; Makoto Kobayashi; Takuji Oda; Masanori Hara; Hideo Watanabe; Yuji Hatano; Pattrick Calderoni; Kenji Okuno

    2011-12-01T23:59:59.000Z

    The behavior of D retention for Fe{sup 2+}-irradiated tungsten with a damage of 0.025-3 dpa was compared with that for neutron-irradiated tungsten with 0.025 dpa. The D{sub 2} thermal desorption spectroscopy (TDS) spectra for Fe{sup 2+}-irradiated tungsten consisted of two desorption stages at 450 and 550 K, while that for neutron-irradiated tungsten was composed of three stages and an addition desorption stage was found at 750 K. The desorption rate of the major desorption stage at 550K increased as the displacement damage increased due to Fe{sup 2+} irradiation increasing. In addition, the first desorption stage at 450K was found only for damaged samples. Therefore, the second stage would be based on intrinsic defects or vacancy produced by Fe{sup 2+} irradiation, and the first stage should be the accumulation of D in mono-vacancy and the activation energy would be relatively reduced, where the dislocation loop and vacancy is produced. The third one was found only for neutron irradiation, showing the D trapping by a void or vacancy cluster, and the diffusion effect is also contributed to by the high full-width at half-maximum of the TDS spectrum. Therefore, it can be said that the D{sub 2} TDS spectra for Fe{sup 2+}-irradiated tungsten cannot represent that for the neutron-irradiated one, indicating that the deuterium trapping and desorption mechanism for neutron-irradiated tungsten is different from that for the ion-irradiated one.

  18. Utilization of geothermal energy in the mining and processing of tungsten ore. Quarterly report

    SciTech Connect (OSTI)

    Lane, C.K.; Erickson, M.V.; Lowe, G.D.

    1980-02-01T23:59:59.000Z

    The status of the engineering and economic feasibility study of utilizing geothermal energy for the mining and processing of tungsten ore at the Union Carbide-Metals Division Pine Creek tungsten complex near Bishop, Calfironia is reviewed. Results of geophysical data analysis including determination of assumed resource parameters are presented. The energy utilization evaluation identifies potential locations for substituting geothermal energy for fossil fuel energy using current technology. Preliminary analyses for local environmental and institutional barriers to development of a geothermal system are also provided.

  19. Measurements of Nucleon-Induced Fission Cross-Sections of Separated Tungsten Isotopes and Natural Tungsten in the 50-200 MeV Energy Region

    E-Print Network [OSTI]

    V. P. Eismont; N. P. Filatov; A. N. Smirnov; S. M. Soloviev; J. Blomgren; H. Conde; A. V. Prokofiev; S. G. Mashnik

    2005-07-07T23:59:59.000Z

    Neutron- and proton-induced fission cross-sections of separated isotopes of tungsten (182W, 183W, 184W, and 186W) and natural tungsten relative to 209Bi have been measured in the incident nucleon energy region 50-200 MeV using fission chambers based on thin-film breakdown counters (TFBC) at quasi-monoenergetic neutrons from the 7Li(p,n) reaction and at the proton beams of The Svedberg Laboratory (TSL), Uppsala University (Uppsala, Sweden). The preliminary experimental data are presented in comparison with the recent data for nuclei in the lead-bismuth region, as well as with predictions by the CEM03.01 event generator.

  20. Dynamic Resource Allocation with the arcControlTower

    E-Print Network [OSTI]

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01T23:59:59.000Z

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers’ workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job management system (PanDA) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experienc...

  1. CHEP2015: Dynamic Resource Allocation with arcControlTower

    E-Print Network [OSTI]

    Filipcic, Andrej; The ATLAS collaboration; Nilsen, Jon Kerr

    2015-01-01T23:59:59.000Z

    Distributed computing resources available for high-energy physics research are becoming less dedicated to one type of workflow and researchers’ workloads are increasingly exploiting modern computing technologies such as parallelism. The current pilot job management model used by many experiments relies on static dedicated resources and cannot easily adapt to these changes. The model used for ATLAS in Nordic countries and some other places enables a flexible job management system based on dynamic resources allocation. Rather than a fixed set of resources managed centrally, the model allows resources to be requested on the fly. The ARC Computing Element (ARC-CE) and ARC Control Tower (aCT) are the key components of the model. The aCT requests jobs from the ATLAS job mangement system (Panda) and submits a fully-formed job description to ARC-CEs. ARC-CE can then dynamically request the required resources from the underlying batch system. In this paper we describe the architecture of the model and the experience...

  2. Arcing fault in sub-distribution branch circuits

    SciTech Connect (OSTI)

    Parise, G.; Grasseli, U.; Luozzo, V. Di (Univ. di Roma, Rome (Italy). Dept. di Ingegneria Elettrica)

    1993-04-01T23:59:59.000Z

    It's well known the importance of short-circuit current evaluation for the design of any power system. Every system is subject to faults, moreover short-circuits and ground faults can be expected in any point. Even if the maximum and minimum values are generally defined with reference at a bolted-fault, bolted short-circuits are rare and the fault usually involves arcing and burning; particularly the limit value of minimum short-circuit depends really on arcing-fault. In earlier experimental investigations into the functional simulation of insulation loss, in branch circuit conductors, the authors chose to normalize the arcing-fault simulation to be used in laboratory tests. This conventional simulation allows characterization of this intrinsically random phenomenon by means of a probabilistic approach, in order to define in statistical terms the expected short circuit value. The authors examine more closely the arcing-fault in the design of sub distribution branch-circuits as weak points of the installation. In fact, what they propose are straightforward criteria, whether in the structure of the system or in the coordination of protection, which afford a more rational control on arcing-fault.

  3. Graphite electrode arc melter demonstration Phase 2 test results

    SciTech Connect (OSTI)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; O`Connor, W.K.; Oden, L.L.; Turner, P.C.

    1996-06-01T23:59:59.000Z

    Several U.S. Department of Energy organizations and the U.S. Bureau of Mines have been collaboratively conducting mixed waste treatment process demonstration testing on the near full-scale graphite electrode submerged arc melter system at the Bureau`s Albany (Oregon) Research Center. An initial test series successfully demonstrated arc melter capability for treating surrogate incinerator ash of buried mixed wastes with soil. The conceptual treatment process for that test series assumed that buried waste would be retrieved and incinerated, and that the incinerator ash would be vitrified in an arc melter. This report presents results from a recently completed second series of tests, undertaken to determine the ability of the arc melter system to stably process a wide range of {open_quotes}as-received{close_quotes} heterogeneous solid mixed wastes containing high levels of organics, representative of the wastes buried and stored at the Idaho National Engineering Laboratory (INEL). The Phase 2 demonstration test results indicate that an arc melter system is capable of directly processing these wastes and could enable elimination of an up-front incineration step in the conceptual treatment process.

  4. Transient Thermal and Stress Response of A Helium-Cooled Tungsten Plate-Type Divertor

    E-Print Network [OSTI]

    Raffray, A. René

    Transient Thermal and Stress Response of A Helium- Cooled Tungsten Plate-Type Divertor X.R. Wang, A and shutdown operations have been analyzed with a coupled transient thermo-fluid and thermal-stress approach and investigated for power plant applications with a goal of accommodating a heat flux of 10 MW/m2 . The concepts

  5. Tungsten uptake kinetics and trophic1 transfer into a novel gastropod model2

    E-Print Network [OSTI]

    Ma, Lena

    exploration of its relevant environmental and biological pathways. This investigation presents the most7 some27 siderophilic tendencies that are very similar to uranium and thorium, and which have similar it a unique29 element. Tungsten has one of the greatest densities (19.25 g/cm3 ), after only uranium

  6. Submersion Criticality Safety Analysis of Tungsten-Based Fuel for Nuclear Power and Propulsion Applications

    SciTech Connect (OSTI)

    A.E. Craft; R. C. O'Brien; S. D. Howe; J. C. King

    2014-07-01T23:59:59.000Z

    The Center for Space Nuclear Research (CSNR) is developing tungsten-encapsulated fuels for space nuclear applications. Aims to develop NTP fuels that are; Affordable Low impact on production and testing environment Producible on a large scale over suitable time period Higher-performance compared to previous graphite NTP fuel elements Space nuclear reactors remain subcritical before and during launch, and do not go critical until required by its mission. A properly designed reactor will remain subcritical in any launch abort scenario, where the reactor falls back to Earth and becomes submerged in terrestrial material. Submersion increases neutron reflection and thermalizes the neutrons, which typically increases the reactivity of the core. This effect is usually very significant for fast-spectrum reactors. This research provided a submersion criticality safety analysis for a representative tungsten/uranium oxide fueled reactor. Determine the submersion behavior of a reactor fueled by tungsten-based fuel. Considered fuel compositions with varying: Rhenium content (wt% rhenium in tungsten) Fuel loading fractions (UO2 vol%)

  7. Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    Micro-engineered first wall tungsten armor for high average power laser fusion energy systems is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first is a coordinated effort to develop laser inertial fusion energy [1]. The first stage of the HAPL program

  8. ULTRA LOW PRESSURE-DROP HELIUM-COOLED POROUS-TUNGSTEN PFC S. Sharafat1

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    ULTRA LOW PRESSURE-DROP HELIUM-COOLED POROUS-TUNGSTEN PFC S. Sharafat1 , A. Mills1 , D. Youchison2/s. Based on these impressive performance results, a unique and scalable heat exchanger channel with ultra-low and ultra low-pressure drop short flow-path (SOFIT) concept was designed. Typical pressure drops through

  9. Laminated electrochromic windows based on nickel oxide, tungsten oxide, and gel electrolytes

    SciTech Connect (OSTI)

    Passerini, S.; Scrosati, B.; Hermann, V. (Univ. di Roma (Italy). Dipt. di Chimica); Holmblad, C.; Bartlett, T. (Medtronic Promeon, Minneapolis, MN (United States))

    1994-04-01T23:59:59.000Z

    The characteristic and the performance of solid-state, laminated electrochromic windows using tungsten oxide as the principal electrochromic electrode and nonstoichiometric nickel oxide as the counterelectrode separated by selected gel electrolytes, are presented and discussed. These advanced-design, electro-optical devices show a very promising behavior in terms of light modulation and cyclability.

  10. Helium Jet-Cooled Tungsten Divertor Concept J.S. O'Della

    E-Print Network [OSTI]

    Raffray, A. René

    Helium Jet-Cooled Tungsten Divertor Concept J.S. O'Della and A.R. Raffrayb a Plasma Processes, Inc., Huntsville, Alabama, USA b University of California ­ San Diego, La Jolla, California, USA Abstract-- Helium helium cooling techniques for high heat flux (HHF) applications. However, because of the small size

  11. The role of helium implantation induced vacancy defect on hardening of tungsten

    SciTech Connect (OSTI)

    Ou, Xin, E-mail: x.ou@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200250 (China); Anwand, Wolfgang, E-mail: w.anwand@hzdr.de; Kögler, Reinhard, E-mail: r.koegler@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Zhou, Hong-Bo [Department of Physics, Beihang University, Beijing 100191 (China); Richter, Asta, E-mail: asta.richter@th-wildau.de [Technische Hochschule Wildau, Hochschulring1, 15745 Wildau (Germany)

    2014-03-28T23:59:59.000Z

    Vacancy-type defects created by helium implantation in tungsten and their impact on the nano-hardness characteristics were investigated by correlating the results from the positron annihilation spectroscopy and the nano-indentation technique. Helium implantation was performed at room temperature (RT) and at an elevated temperate of 600?°C. Also, the effect of post-annealing of the RT implanted sample was studied. The S parameter characterizing the open volume in the material was found to increase after helium irradiation and is significantly enhanced for the samples thermally treated at 600?°C either by irradiation at high temperature or by post-annealing. Two types of helium-vacancy defects were detected after helium irradiation; small defects with high helium-to-vacancy ratio (low S parameter) for RT irradiation and large defects with low helium-to-vacancy ratio (high S parameter) for thermally treated tungsten. The hardness of the heat treated tungsten coincides with the S parameter, and hence is controlled by the large helium-vacancy defects. The hardness of tungsten irradiated at RT without thermal treatment is dominated by manufacturing related defects such as dislocation loops and impurity clusters and additionally by trapped He atoms from irradiation effects, which enhance hardness. He-stabilized dislocation loops mainly cause the very high hardness values in RT irradiated samples without post-annealing.

  12. Interactions of mobile helium clusters with surfaces and grain boundaries of plasma-exposed tungsten

    SciTech Connect (OSTI)

    Hu, Lin; Maroudas, Dimitrios, E-mail: maroudas@ecs.umass.edu [Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003-9303 (United States); Hammond, Karl D.; Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2014-05-07T23:59:59.000Z

    We report results of atomistic computations for the interactions of small mobile helium clusters (He{sub n}) with free surfaces and grain boundaries (GBs) in tungsten toward development of continuum drift-diffusion-reaction models for the dynamics of mobile helium clusters in plasma-exposed tungsten. Molecular-statics (MS) simulations based on reliable many-body interatomic potentials are carried out for He{sub n} (1???n???7) clusters near sinks to obtain the potential energy profiles of the He{sub n} clusters as a function of the clusters' center-of-mass distance from a sink. Sinks investigated include surfaces, GBs, and regions in the vicinity of junctions where GBs intersect free surfaces. Elastic interaction potentials based on elastic inclusion theory provide an excellent description of the MS results for the cluster-sink interactions. The key parameter in the elastic models is the sink segregation strength, which is found to increase with increasing cluster size. Such cluster-sink interactions are responsible for the migration of small helium clusters by drift and for helium segregation on surfaces and grain boundaries in tungsten. Such helium segregation on sinks is observed in large-scale molecular-dynamics simulations of helium aggregation in model polycrystalline tungsten at 933?K upon helium implantation.

  13. Materials Corrosion and Mitigation Strategies for APT: Using Solution Resistivity as an Estimate of Tungsten Corrosion

    E-Print Network [OSTI]

    Materials Corrosion and Mitigation Strategies for APT: Using Solution Resistivity as an Estimate of Tungsten Corrosion in Spallation Neutron Target Cooling Loops R. Scott Lillard, Darryl P. Butt Materials Corrosion and Environmental Effects Laboratory MST-6, Metallurgy Los Alamos National Laboratory Los Alamos

  14. Tungsten nano-tendril growth in the Alcator C-Mod divertor

    E-Print Network [OSTI]

    Baldwin, M.J.

    Growth of tungsten nano-tendrils ('fuzz') has been observed for the first time in the divertor region of a high-power density tokamak experiment. After 14 consecutive helium L-mode discharges in Alcator C-Mod, the tip of ...

  15. Utilization of geothermal energy in the mining and processing of tungsten ore. Final report

    SciTech Connect (OSTI)

    Erickson, M.V.; Lacy, S.B.; Lowe, G.D.; Nussbaum, A.M.; Walter, K.M.; Willens, C.A.

    1981-01-01T23:59:59.000Z

    The engineering, economic, and environmental feasibility of the use of low and moderate temperature geothermal heat in the mining and processing of tungsten ore is explored. The following are covered: general engineering evaluation, design of a geothermal energy system, economics, the geothermal resource, the institutional barriers assessment, environmental factors, an alternate geothermal energy source, and alternates to geothermal development. (MHR)

  16. Defect production in tungsten: A comparison between field-ion microscopy and molecular-dynamics simulations

    E-Print Network [OSTI]

    Nordlund, Kai

    Defect production in tungsten: A comparison between field-ion microscopy and molecular defect production efficiencies obtained by FIM are a consequence of a surface effect, which greatly enhances defect production compared to that in the crystal interior. Comparison of clustering of vacancies

  17. MODELING SPACE-TIME DEPENDENT HELIUM BUBBLE EVOLUTION IN TUNGSTEN ARMOR UNDER IFE CONDITIONS

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    MODELING SPACE-TIME DEPENDENT HELIUM BUBBLE EVOLUTION IN TUNGSTEN ARMOR UNDER IFE CONDITIONS Qiyang dependent Helium transport in finite geometries, including the simultaneous transient production of defects of Helium bubbles. I. INTRODUCTION Helium production and helium bubble evolution in neutron

  18. SPS Fabrication of Tungsten-Rhenium Alloys in Support of NTR Fuels Development

    SciTech Connect (OSTI)

    Jonathan A. Webb; Indrajit Charit; Cory Sparks; Darryl P. Butt; Megan Frary; Mark Carroll

    2011-02-01T23:59:59.000Z

    Abstract. Tungsten metal slugs were fabricated via Spark Plasma Sintering (SPS) of powdered metals at temperatures ranging from 1575 K to 1975 K and hold times of 5 minutes to 30 minutes, using powders with an average diameter of 7.8 ?m. Sintered tungsten specimens were found to have relative densities ranging from 83 % to 94 % of the theoretical density for tungsten. Consolidated specimens were also tested for their Vickers Hardness Number (VHN), which was fitted as a function of relative density; the fully consolidated VHN was extrapolated to be 381.45 kg/mm2. Concurrently, tungsten and rhenium powders with average respective diameters of 0.5 ?m and 13.3 ?m were pre-processed either by High-Energy-Ball-Milling (HEBM) or by homogeneous mixing to yield W-25at.%Re mixtures. The powder batches were sintered at temperatures of 1975 K and 2175 K for hold times ranging from 0 minutes to 60 minutes yielding relative densities ranging from 94% to 97%. The combination of HEBM and sintering showed a significant decrease in the inter-metallic phases compared to that of the homogenous mixing and sintering.

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

    SciTech Connect (OSTI)

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

    2014-05-01T23:59:59.000Z

    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.

  20. High Charge State Ions Extracted from Metal Plasmas in the Transition Regime from Vacuum Spark to High Current Vacuum Arc

    E-Print Network [OSTI]

    Anders, Georgy, Yu. Yushkov, Andre

    2008-01-01T23:59:59.000Z

    emitted by dc arcs in a vacuum ambient," J. Appl. Phys. ,Plasma properties of a metal vacuum arc. II. ” Sov. Phys.1977. [4] I. G. Brown, “Vacuum arc ion sources”, Rev. Sci.

  1. Parallel vacuum arc discharge with microhollow array dielectric and anode

    SciTech Connect (OSTI)

    Feng, Jinghua; Zhou, Lin; Fu, Yuecheng; Zhang, Jianhua; Xu, Rongkun; Chen, Faxin; Li, Linbo; Meng, Shijian, E-mail: mengshijian04@126.com [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China)

    2014-07-15T23:59:59.000Z

    An electrode configuration with microhollow array dielectric and anode was developed to obtain parallel vacuum arc discharge. Compared with the conventional electrodes, more than 10 parallel microhollow discharges were ignited for the new configuration, which increased the discharge area significantly and made the cathode eroded more uniformly. The vacuum discharge channel number could be increased effectively by decreasing the distances between holes or increasing the arc current. Experimental results revealed that plasmas ejected from the adjacent hollow and the relatively high arc voltage were two key factors leading to the parallel discharge. The characteristics of plasmas in the microhollow were investigated as well. The spectral line intensity and electron density of plasmas in microhollow increased obviously with the decease of the microhollow diameter.

  2. Darwin : The Third DOE ARM TWP ARCS Site /

    SciTech Connect (OSTI)

    Clements, William E.; Jones, L. A. (Larry A.); Baldwin, T. (Tony); Nitschke, K. (Kim)

    2002-01-01T23:59:59.000Z

    The United States Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) Program began operations in its Tropical Western Pacific (TWP) locale in October 1996 when the first Atmospheric Radiation and Cloud Station (ARCS) began collecting data on Manus Island in Papua New Guinea (PNG). Two years later, in November 1998, a second ARCS began operations on the island of Nauru in the Central Pacific. Now a third ARCS has begun collecting data in Darwin, Australia. The Manus, Nauru, and Darwin sites are operated through collaborative agreements with the PNG National Weather Service, The Nauru Department of Industry and Economic Development (IED), and the Australian Bureau of Meteorology's (BOM) Special Services Unit (SSU) respectively. All ARM TWP activities in the region are coordinated with the South Pacific Regional Environment Programme (SPREP) based in Apia, Samoa. The Darwin ARM site and its role in the ARM TWP Program are discussed.

  3. Waste Heat Recovery from High Temperature Off-Gases from Electric Arc Furnace

    SciTech Connect (OSTI)

    Nimbalkar, Sachin U [ORNL; Thekdi, Arvind [E3M Inc; Keiser, James R [ORNL; Storey, John Morse [ORNL

    2014-01-01T23:59:59.000Z

    This article presents a study and review of available waste heat in high temperature Electric Arc Furnace (EAF) off gases and heat recovery techniques/methods from these gases. It gives details of the quality and quantity of the sensible and chemical waste heat in typical EAF off gases, energy savings potential by recovering part of this heat, a comprehensive review of currently used waste heat recovery methods and potential for use of advanced designs to achieve a much higher level of heat recovery including scrap preheating, steam production and electric power generation. Based on our preliminary analysis, currently, for all electric arc furnaces used in the US steel industry, the energy savings potential is equivalent to approximately 31 trillion Btu per year or 32.7 peta Joules per year (approximately $182 million US dollars/year). This article describes the EAF off-gas enthalpy model developed at Oak Ridge National Laboratory (ORNL) to calculate available and recoverable heat energy for a given stream of exhaust gases coming out of one or multiple EAF furnaces. This Excel based model calculates sensible and chemical enthalpy of the EAF off-gases during tap to tap time accounting for variation in quantity and quality of off gases. The model can be used to estimate energy saved through scrap preheating and other possible uses such as steam generation and electric power generation using off gas waste heat. This article includes a review of the historical development of existing waste heat recovery methods, their operations, and advantages/limitations of these methods. This paper also describes a program to develop and test advanced concepts for scrap preheating, steam production and electricity generation through use of waste heat recovery from the chemical and sensible heat contained in the EAF off gases with addition of minimum amount of dilution or cooling air upstream of pollution control equipment such as bag houses.

  4. Evaporation-assisted high-power impulse magnetron sputtering: The deposition of tungsten oxide as a case study

    SciTech Connect (OSTI)

    Hemberg, Axel; Dauchot, Jean-Pierre; Snyders, Rony; Konstantinidis, Stephanos [Materia Nova Research Center-Parc Initialis, 1, Avenue Copernic, B-7000 Mons, Belgium and Chimie des Interactions Plasma-Surface, CIRMAP, Universite de Mons-20, Place du Parc, B-7000 Mons (Belgium); Chimie des Interactions Plasma-Surface, CIRMAP, Universite de Mons-20, Place du Parc, B-7000 Mons (Belgium); Materia Nova Research Center-Parc Initialis, 1, Avenue Copernic, B-7000 Mons (Belgium) and Chimie des Interactions Plasma-Surface, CIRMAP, Universite de Mons-20, Place du Parc, B-7000 Mons (Belgium); Chimie des Interactions Plasma-Surface, CIRMAP, Universite de Mons-20, Place du Parc, B-7000 Mons (Belgium)

    2012-07-15T23:59:59.000Z

    The deposition rate during the synthesis of tungsten trioxide thin films by reactive high-power impulse magnetron sputtering (HiPIMS) of a tungsten target increases, above the dc threshold, as a result of the appropriate combination of the target voltage, the pulse duration, and the amount of oxygen in the reactive atmosphere. This behavior is likely to be caused by the evaporation of the low melting point tungsten trioxide layer covering the metallic target in such working conditions. The HiPIMS process is therefore assisted by thermal evaporation of the target material.

  5. Multi-cathode metal vapor arc ion source

    DOE Patents [OSTI]

    Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); MacGill, Robert A. (645 Kern St., Richmond, CA 94805)

    1988-01-01T23:59:59.000Z

    An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam. One embodiment of the appaatus utilizes a multi-cathode arrangement for interaction with the anode.

  6. Graphite electrode DC arc furnace. Innovative technology summary report

    SciTech Connect (OSTI)

    NONE

    1999-05-01T23:59:59.000Z

    The Graphite Electrode DC Arc Furnace (DC Arc) is a high-temperature thermal process, which has been adapted from a commercial technology, for the treatment of mixed waste. A DC Arc Furnace heats waste to a temperature such that the waste is converted into a molten form that cools into a stable glassy and/or crystalline waste form. Hazardous organics are destroyed through combustion or pyrolysis during the process and the majority of the hazardous metals and radioactive components are incorporated in the molten phase. The DC Arc Furnace chamber temperature is approximately 593--704 C and melt temperatures are as high as 1,500 C. The DC Arc system has an air pollution control system (APCS) to remove particulate and volatiles from the offgas. The advantage of the DC Arc is that it is a single, high-temperature thermal process that minimizes the need for multiple treatment systems and for extensive sorting/segregating of large volumes of waste. The DC Arc has the potential to treat a wide range of wastes, minimize the need for sorting, reduce the final waste volumes, produce a leach resistant waste form, and destroy organic contaminants. Although the DC arc plasma furnace exhibits great promise for treating the types of mixed waste that are commonly present at many DOE sites, several data and technology deficiencies were identified by the Mixed Waste Focus Area (MWFA) regarding this thermal waste processing technique. The technology deficiencies that have been addressed by the current studies include: establishing the partitioning behavior of radionuclides, surrogates, and hazardous metals among the product streams (metal, slag, and offgas) as a function of operating parameters, including melt temperature, plenum atmosphere, organic loading, chloride concentration, and particle size; demonstrating the efficacy of waste product removal systems for slag and metal phases; determining component durability through test runs of extended duration, evaluating the effect of feed composition variations on process operating conditions and slag product performance; and collecting mass balance and operating data to support equipment and instrument design.

  7. Thermocapillary and arc phenomena in stainless steel welds

    SciTech Connect (OSTI)

    Pierce, S.W.

    1993-10-01T23:59:59.000Z

    Goal was to study effect of power level and distribution on thermocapiilary-induced weld shape and of arc factors on weld shape. Thermocapillarity was apparent in both conduction mode EB welds and GTA welds, particularly in the former. A non-Gaussian arc distribution is suggested for accounting for the differences between the twoss processes. At higher current levels (200--300 A), plasma shear force also contributes to weld shape development. Evidence suggests that thermocapillary flow reversal is not a factor in normal GTA welds; EDB flow reversal occurs only at high power density levels where the keyhole mode is present.

  8. E-Print Network 3.0 - arc plasma deposition Sample Search Results

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

    deposition of TiN coatings to increase... was built at FCIPT for studying SpacecraftSolar panel - Plasma' interactions that can lead to arcing... which lead to arcing. The...

  9. Characterization of argon arc source in the infrared J. M. Bridges and A. L. Migdall

    E-Print Network [OSTI]

    Migdall, Alan

    metrologia Characterization of argon arc source in the infrared J. M. Bridges and A. L. Migdall path. Although a resistor of 0,25 is used for ignition, the arc requires no ballast during Metrologia

  10. Optical emission spectroscopy of metal vapor dominated laser-arc hybrid welding plasma

    SciTech Connect (OSTI)

    Ribic, B.; DebRoy, T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Burgardt, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2011-04-15T23:59:59.000Z

    During laser-arc hybrid welding, plasma properties affect the welding process and the weld quality. However, hybrid welding plasmas have not been systematically studied. Here we examine electron temperatures, species densities, and electrical conductivity for laser, arc, and laser-arc hybrid welding using optical emission spectroscopy. The effects of arc currents and heat source separation distances were examined because these parameters significantly affect weld quality. Time-average plasma electron temperatures, electron and ion densities, electrical conductivity, and arc stability decrease with increasing heat source separation distance during hybrid welding. Heat source separation distance affects these properties more significantly than the arc current within the range of currents considered. Improved arc stability and higher electrical conductivity of the hybrid welding plasma result from increased heat flux, electron temperatures, electron density, and metal vapor concentrations relative to arc or laser welding.

  11. Rates of tectonic and magmatic processes in the North Cascades continental magmatic arc

    E-Print Network [OSTI]

    Matzel, Jennifer E. Piontek, 1973-

    2004-01-01T23:59:59.000Z

    Continental magmatic arcs are among the most dynamic. geologic systems, and documentation of the magmatic, thermal, and tectonic evolution of arcs is essential for understanding the processes of magma generation, ascent ...

  12. E-Print Network 3.0 - arc plasma melting Sample Search Results

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

    UPDATE A newsletter from the Summary: was built at FCIPT for studying SpacecraftSolar panel - Plasma' interactions that can lead to arcing... which lead to arcing. The range of...

  13. E-Print Network 3.0 - assisted plasma arc Sample Search Results

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

    assisted manufacturing and to look... was built at FCIPT for studying SpacecraftSolar panel - Plasma' interactions that can lead to arcing... which lead to arcing. The range of...

  14. Longitudinally propagating arc wave in the pre-onset optical aurora V. M. Uritsky,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    Longitudinally propagating arc wave in the pre-onset optical aurora V. M. Uritsky,1 J. Liang,1 E aurora ­ the longitudinally propagating arc wave (LPAW) ­ associated with flapping oscillations, and K. H. Glassmeier (2009), Longitudinally propagating arc wave in the pre-onset optical aurora

  15. Control Engineering Practice 11 (2003) 14011411 Modeling and control of quasi-keyhole arc welding process

    E-Print Network [OSTI]

    Zhang, YuMing

    Control Engineering Practice 11 (2003) 1401­1411 Modeling and control of quasi-keyhole arc welding to operate the keyhole arc welding process. Because the method's effectiveness depends on the amperage reserved. Keywords: Modeling; Predictive control; Manufacturing; Welding 1. Introduction Keyhole arc

  16. ~.,Slag-Metal Equilibrium During Submerged e-~~ Arc Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ~~ . ~.·,Slag-Metal Equilibrium During Submerged ·e-~~ Arc Welding C. S. CHAI AND T. W. EAGAR A thermodynamic model of the equilibria existing between the slag and the weld metal during submerged arc welding over forty years ago, submerged arc welding has developed into one of the most efficient, most reliable

  17. Individualization of textural and reactional microdomains in eclogites from the Bergen Arcs (Norway): Consequences for

    E-Print Network [OSTI]

    Demouchy, Sylvie

    Individualization of textural and reactional microdomains in eclogites from the Bergen Arcs (Norway in Caledonian eclogites from the Linda°s Nappe, Bergen Arcs, Norway, in order to investigate processes in eclogites from the Bergen Arcs (Norway): Consequences for Rb/Sr and Ar/Ar radiochronometer behavior during

  18. Characteristics of a stable arc based on FAST and MIRACLE observations

    E-Print Network [OSTI]

    Boyer, Edmond

    , which contains all-sky cameras, coherent radars (STARE), and magnetometers. Both FAST and STARE observe of the arc, which is a typical signature for an evening-sector arc. The ®eld-aligned current deter- mined of small undulations associated with the arc using the all-sky cameras gives a velocity of about 2 km

  19. ACYCLIC GROUPS AND WILD ARCS A. J. BERRICK AND YAN-LOI WONG

    E-Print Network [OSTI]

    Berrick, A J.

    ACYCLIC GROUPS AND WILD ARCS A. J. BERRICK AND YAN-LOI WONG Abstract. We discuss two classes, and is shown to include a number of wild arc groups in the literature. 0. Introduction This paper introduces cyclic cover of X \\ is the complement of a wild arc in S3 with the following properties. (i) S3

  20. Sediment Budget Analysis System (SBAS) for ArcGIS 10 -User's Guide Page 1 of 49

    E-Print Network [OSTI]

    US Army Corps of Engineers

    Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 1 of 49 CESAM-OPJ-GIS Document current as of March 28, 2012 10:27 AM Sediment Budget Analysis System (SBAS) for ArcGIS 10 User's Guide D R AFT #12;Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 2 of 49 CESAM

  1. Sediment Budget Analysis System (SBAS) for ArcGIS 10 -User's Guide Page 1 of 50

    E-Print Network [OSTI]

    US Army Corps of Engineers

    Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 1 of 50 CESAM-OPJ-GIS Document current as of June 27, 2012 10:09 AM Sediment Budget Analysis System (SBAS) for ArcGIS 10 User's Guide D R AFT #12;Sediment Budget Analysis System (SBAS) for ArcGIS 10 - User's Guide Page 2 of 50 CESAM

  2. Pulse thermal processing of functional materials using directed plasma arc

    DOE Patents [OSTI]

    Ott, Ronald D. (Knoxville, TN); Blue, Craig A. (Knoxville, TN); Dudney, Nancy J. (Knoxville, TN); Harper, David C. (Kingston, TN)

    2007-05-22T23:59:59.000Z

    A method of thermally processing a material includes exposing the material to at least one pulse of infrared light emitted from a directed plasma arc to thermally process the material, the pulse having a duration of no more than 10 s.

  3. arc box test: Topics by E-print Network

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

    arc box test First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 WHITE BOX TESTING TECHNIQUE CiteSeer...

  4. Self-organisation Processes In The Carbon ARC For Nanosynthis

    SciTech Connect (OSTI)

    Ng, Jonathan; Raitses, Yevgeny

    2014-02-26T23:59:59.000Z

    The atmospheric pressure carbon arc in inert gases such as helium is an important method for the production of nanomaterials. It has recently been shown that the formation of the carbon deposit on the cathode from gaseous carbon plays a crucial role in the operation of the arc, reaching the high temperatures necessary for thermionic emission to take place even with low melting point cathodes. Based on observed ablation and deposition rates, we explore the implications of deposit formation on the energy balance at the cathode surface, and show how the operation of the arc is self-organised process. Our results suggest that the can arc operate in two di erent regimes, one of which has an important contribution from latent heat to the cathode energy balance. This regime is characterised by the enhanced ablation rate, which may be favourable for high yield synthesis of nanomaterials. The second regime has a small and approximately constant ablation rate with a negligible contribution from latent heat.

  5. Self-organisation Processes In The Carbon ARC For Nanosynthis

    SciTech Connect (OSTI)

    Ng, J.; Raitses, Yefgeny [Princeton Plasma Physics Lab., Princeton, NJ (United States)

    2014-02-02T23:59:59.000Z

    The atmospheric pressure carbon arc in inert gases such as helium is an important method for the production of nanomaterials. It has recently been shown that the formation of the carbon deposit on the cathode from gaseous carbon plays a crucial role in the operation of the arc, reaching the high temperatures necessary for thermionic emission to take place even with low melting point cathodes. Based on observed ablation and deposition rates, we explore the implications of deposit formation on the energy balance at the cathode surface, and show how the operation of the arc is self-organised process. Our results suggest that the can arc operate in two di erent regimes, one of which has an important contribution from latent heat to the cathode energy balance. This regime is characterised by the enhanced ablation rate, which may be favourable for high yield synthesis of nanomaterials. The second regime has a small and approximately constant ablation rate with a negligible contribution from latent heat.

  6. A Generic Arc-Consistency Algorithm and its Specializations1

    E-Print Network [OSTI]

    Deville, Yves

    not take into account the semantics of constraints. In this paper, we present a new generic arc satisfaction problems (CSP). A CSP is de ned by a nite set of variables taking values from nite domains of applications include graph-coloring, warehouse locations, car-sequencing and cutting stock (see for instance 4

  7. A Generic ArcConsistency Algorithm and its Specializations 1

    E-Print Network [OSTI]

    Deville, Yves

    , these algorithms do not take into account the semantics of constraints. In this paper, we present a new generic arc as constraint satisfaction problems (CSP). A CSP is defined by a finite set of variables taking values from. Examples of applications include graph­coloring, warehouse locations, car­sequencing and cutting stock (see

  8. Detection and Differentiation of Neutral Organic Compounds by [superscript 19]F NMR with a Tungsten Calix[4]arene Imido Complex

    E-Print Network [OSTI]

    Zhao, Yanchuan

    Fluorinated tungsten calix[4]arene imido complexes were synthesized and used as receptors to detect and differentiate neutral organic compounds. It was found that the binding of specific neutral organic molecules to the ...

  9. Chapter 30: Quantum Physics 9. The tungsten filament in a standard light bulb can be considered a blackbody radiator.

    E-Print Network [OSTI]

    Kioussis, Nicholas

    . 1 Chapter 30: Quantum Physics 9. The tungsten filament in a standard light bulb can be considered frequency is that of infrared electromagnetic radiation, the light bulb radiates more energy in the infrared

  10. Z-Selective Metathesis Homocoupling of 1,3-Dienes by Molybdenum and Tungsten Monoaryloxide Pyrrolide (MAP) Complexes

    E-Print Network [OSTI]

    Hoveyda, Amir H.

    Molybdenum or tungsten monoaryloxide pyrrolide (MAP) complexes that contain OHIPT as the aryloxide (hexaisopropylterphenoxide) are effective catalysts for homocoupling of simple (E)-1,3-dienes to give (E,Z,E)-trienes in ...

  11. Enhanced catalyst and process for converting synthesis gas to liquid motor fuels

    DOE Patents [OSTI]

    Coughlin, Peter K. (Yorktown Heights, NY)

    1986-01-01T23:59:59.000Z

    The conversion of synthesis gas to liquid molar fuels by means of a cobalt Fischer-Tropsch catalyst composition is enhanced by the addition of molybdenum, tungsten or a combination thereof as an additional component of said composition. The presence of the additive component increases the olefinic content of the hydrocarbon products produced. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

  12. Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical Intra-oceanic Arc1

    E-Print Network [OSTI]

    Stern, Robert J.

    Glass Inclusions in Mariana Arc Phenocrysts: A New Perspective on Magmatic Evolution in a Typical at Dallas, Box 830688, Richardson, TX 75083-0688, USA A B S T R A C T Major element compositions of glass of these lavas reflects accumulation of plagioclase. Glass inclusions also show the common occurrence of felsic

  13. Use of nafion as a solid polymer electrolyte for the electroreduction of tungsten (VI) fluoride

    SciTech Connect (OSTI)

    Bettelheim, A.; Raven, A.; Polak, M.; Ozer, D. (Nuclear Research Center, Beer-Sheva 84190 (IL))

    1992-01-01T23:59:59.000Z

    In this paper a new method is described in which WF{sub 6} is electroreduced in a solid-state cell configuration with a Nafion membrane serving as a solid polymer electrolyte. Cyclic voltammetry indicates a behavior similar to that of metallic tungsten for coatings obtained at dry conditions and similar to that of tungsten oxide species when water vapor is not totally expelled. Surface analysis using Auger electroscope and x-ray photoelectron spectroscopy shows that solid-state electro-reduction of WF{sub 6} in dry conditions yields coatings free of fluorine, which contain much less oxygen than electrodeposits obtained from aqueous solutions. However, due to possible oxidation and reduction reactions occurring before and during the surface-analysis process, it is not possible at this state to determine the exact content of metallic and oxide species in the deposits obtained by the present method.

  14. Test and characterization of a prototype silicon-tungsten electromagnetic calorimeter

    E-Print Network [OSTI]

    Sanjib Muhuri; Sourav Mukhopadhyay; Vinay B. Chandratre; Menka Sukhwani; Satyajit Jena; Shuaib Ahmad Khan; Tapan K. Nayak; Jogender Saini; Rama Narayana Singaraju

    2014-07-22T23:59:59.000Z

    New generation high-energy physics experiments demand high precision tracking and accurate measurements of a large number of particles produced in the collisions of lementary particles and heavy-ions. Silicon-tungsten (Si-W) calorimeters provide the most viable technological option to meet the requirements of particle detection in high multiplicity environments. We report a novel Si-W calorimeter design, which is optimized for $\\gamma/\\pi^0$ discrimination up to high momenta. In order to test the feasibility of the calorimeter, a prototype mini-tower was constructed using silicon pad detector arrays and tungsten layers. The performance of the mini-tower was tested using pion and electron beams at the CERN Proton Synchrotron (PS). The experimental results are compared with the results from a detailed GEANT-4 simulation. A linear relationship between the observed energy deposition and simulated response of the mini-tower has been obtained, in line with our expectations.

  15. The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers

    E-Print Network [OSTI]

    Adloff, C; Chefdeville, M.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Koletsou, I.; Prast, J.; Vouters, G.; Repond, J.; Schlereth, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Eigen, G.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Arfaoui, A.; Benoit, M.; Dannheim, D.; Elsener, K.; Folger, G.; Grefe, C.; Ivantchenko, V.; Killenberg, M.; Klempt, W.; van der Kraaij, E.; Linssen, L.; Lucaci-Timoce, A.-I.; Münnich, A.; Poss, S.; Ribon, A.; Roloff, P.; Sailer, A.; Schlatter, D.; Sicking, E.; Strube, J.; Uzhinskiy, V.; Carloganu, C.; Gay, P.; Manen, S.; Royer, L.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Feege, N.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Fagot, A.; Tytgat, M.; Zaganidis, N.; Hostachy, J.-Y.; Morin, L.; Garutti, E.; Laurien, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Miyazaki, Y.; Sudo, Y.; Ueno, H.; Yoshioka, T.; Dauncey, P.D.; Cortina Gil, E.; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Della Negra, R.; Ete, R.; Grenier, G.; Han, R.; Ianigro, J-C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Vander Donckt, M.; Zoccarato, Y.; Berenguer Antequera, J.; Calvo Alamillo, E.; Fouz, M.-C.; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Rusinov, V.; Tarkovsky, E.; Kozlov, V.; Soloviev, Y.; Besson, D.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Popova, E.; Tikhomirov, V.; Gabriel, M.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Conforti di Lorenzo, S.; Cornebise, P.; Fleury, J.; Frisson, T.; van der Kolk, N.; Richard, F.; Pöschl, R.; Rouene, J.; Anduze, M.; Balagura, V.; Becheva, E.; Boudry, V.; Brient, J-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Ruan, M.; Tran, T.H.; Videau, H.; Callier, S.; Dulucq, F.; Martin-Chassard, G.; de la Taille, Ch.; Raux, L.; Seguin-Moreau, N.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Ono, H.; Takeshita, T.; Uozumi, S.; Chai, J.S.; Song, H.S.; Lee, S.H.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

    2014-01-01T23:59:59.000Z

    The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.

  16. Test and characterization of a prototype silicon-tungsten electromagnetic calorimeter

    E-Print Network [OSTI]

    Muhuri, Sanjib; Chandratre, Vinay B; Sukhwani, Menka; Jena, Satyajit; Khan, Shuaib Ahmad; Nayak, Tapan K; Saini, Jogender; Singaraju, Rama Narayana

    2014-01-01T23:59:59.000Z

    New generation high-energy physics experiments demand high precision tracking and accurate measurements of a large number of particles produced in the collisions of lementary particles and heavy-ions. Silicon-tungsten (Si-W) calorimeters provide the most viable technological option to meet the requirements of particle detection in high multiplicity environments. We report a novel Si-W calorimeter design, which is optimized for $\\gamma/\\pi^0$ discrimination up to high momenta. In order to test the feasibility of the calorimeter, a prototype mini-tower was constructed using silicon pad detector arrays and tungsten layers. The performance of the mini-tower was tested using pion and electron beams at the CERN Proton Synchrotron (PS). The experimental results are compared with the results from a detailed GEANT-4 simulation. A linear relationship between the observed energy deposition and simulated response of the mini-tower has been obtained, in line with our expectations.

  17. Operational Experience and First Results with a Highly Granular Tungsten Analog Hadron Calorimeter

    E-Print Network [OSTI]

    Frank Simon; for the CALICE Collaboration

    2011-11-22T23:59:59.000Z

    Precision physics at future multi-TeV lepton colliders such as CLIC requires excellent jet energy resolution. The detectors need deep calorimeter systems to limit the energy leakage also for very highly energetic particles and jets. At the same time, compact physical dimensions are mandatory to permit the installation of the complete calorimeter system inside high-field solenoidal magnets. This requires very dense absorbers, making tungsten a natural choice for hadron calorimeters at such a future collider. To study the performance of such a calorimeter, a physics prototype with tungsten absorbers and scintillator tiles with SiPM readout as active elements has been constructed and has been tested in particle beams at CERN over a wide energy range from 1 GeV to 300 GeV. We report on the construction and on the operational experience obtained with muon, electron and hadron beams.

  18. The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers

    E-Print Network [OSTI]

    C. Adloff; J. -J. Blaising; M. Chefdeville; C. Drancourt; R. Gaglione; N. Geffroy; Y. Karyotakis; I. Koletsou; J. Prast; G. Vouters J. Repond; J. Schlereth; L. Xia E. Baldolemar; J. Li; S. T. Park; M. Sosebee; A. P. White; J. Yu; G. Eigen; M. A. Thomson; D. R. Ward; D. Benchekroun; A. Hoummada; Y. Khoulaki J. Apostolakis; S. Arfaoui; M. Benoit; D. Dannheim; K. Elsener; G. Folger; C. Grefe; V. Ivantchenko; M. Killenberg; W. Klempt; E. van der Kraaij; L. Linssen; A. -I. Lucaci-Timoce; A. Münnich; S. Poss; A. Ribon; P. Roloff; A. Sailer; D. Schlatter; E. Sicking; J. Strube; V. Uzhinskiy; C. Carloganu; P. Gay; S. Manen; L. Royer; U. Cornett; D. David; A. Ebrahimi; G. Falley; N. Feege; K. Gadow; P. Göttlicher; C. Günter; O. Hartbrich; B. Hermberg; S. Karstensen; F. Krivan; K. Krüger; S. Lu; B. Lutz; S. Morozov; V. Morgunov; C. Neubüser; M. Reinecke; F. Sefkow; P. Smirnov; M. Terwort; A. Fagot; M. Tytgat; N. Zaganidis; J. -Y. Hostachy; L. Morin; E. Garutti; S. Laurien; I. Marchesini; M. Matysek; M. Ramilli; K. Briggl; P. Eckert; T. Harion; H. -Ch. Schultz-Coulon; W. Shen; R. Stamen; S. Chang; A. Khan; D. H. Kim; D. J. Kong; Y. D. Oh; B. Bilki; E. Norbeck; D. Northacker; Y. Onel; G. W. Wilson; K. Kawagoe; Y. Miyazaki; Y. Sudo; H. Ueno; T. Yoshioka; P. D. Dauncey; E. Cortina Gil; S. Mannai; G. Baulieu; P. Calabria; L. Caponetto; C. Combaret; R. Della Negra; R. Ete; G. Grenier; R. Han; J-C. Ianigro; R. Kieffer; I. Laktineh; N. Lumb; H. Mathez; L. Mirabito; A. Petrukhin; A. Steen; W. Tromeur; M. Vander Donckt; Y. Zoccarato J. Berenguer Antequera; E. Calvo Alamillo; M. -C. Fouz; J. Puerta-Pelayo; F. Corriveau; B. Bobchenko; M. Chadeeva; M. Danilov; A. Epifantsev; O. Markin; R. Mizuk; E. Novikov; V. Rusinov; E. Tarkovsky; V. Kozlov; Y. Soloviev; D. Besson; P. Buzhan; A. Ilyin; V. Kantserov; V. Kaplin; E. Popova; V. Tikhomirov; M. Gabriel; C. Kiesling; K. Seidel; F. Simon; C. Soldner; M. Szalay; M. Tesar; L. Weuste; M. S. Amjad; J. Bonis; S. Conforti di Lorenzo; P. Cornebise; J. Fleury; T. Frisson; N. van der Kolk; F. Richard; R. Pöschl; J. Rouene; M. Anduze; V. Balagura; E. Becheva; V. Boudry; J-C. Brient; R. Cornat; M. Frotin; F. Gastaldi; E. Guliyev; Y. Haddad; F. Magniette; M. Ruan; T. H. Tran; H. Videau; S. Callier; F. Dulucq; G. Martin-Chassard; Ch. de la Taille; L. Raux; N. Seguin-Moreau; J. Zacek; J. Cvach; P. Gallus; M. Havranek; M. Janata; J. Kvasnicka; D. Lednicky; M. Marcisovsky; I. Polak; J. Popule; L. Tomasek; M. Tomasek; P. Ruzicka; P. Sicho; J. Smolik; V. Vrba; J. Zalesak; . Belhorma; H. Ghazlane; K. Kotera; H. Ono; T. Takeshita; S. Uozumi; J. S. Chai; H. S. Song; S. H. Lee; M. Götze; J. Sauer; S. Weber; C. Zeitnitz

    2014-07-21T23:59:59.000Z

    The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.

  19. High Strain and Strain-Rate Behaviour of PTFE/Aluminium/Tungsten Mixtures

    E-Print Network [OSTI]

    John Addiss; Jing Cai; Stephen Walley; William Proud; Vitali F. Nesterenko

    2007-11-08T23:59:59.000Z

    Conventional drop-weight techniques were modified to accommodate low-amplitude force transducer signals from low-strength, cold isostatically pressed 'heavy' composites of polytetrafluoroethylene, aluminum and tungsten. The failure strength, strain and the post-critical behavior of failed samples were measured for samples of different porosity and tungsten grain size. Unusual phenomenon of significantly higher strength (55 MPa) of porous composites (density 5.9 g/cc) with small W particles (less than 1 micron) in comparison with strength (32 MPa) of dense composites (7.1 g/cc) with larger W particles (44 microns) at the same volume content of components was observed. This is attributed to force chains created by a network of small W particles. Interrupted tests at different levels of strain revealed the mechanisms of fracture under dynamic compression.

  20. Mechanical characterization and modelling of the heavy tungsten allow IT180

    E-Print Network [OSTI]

    Scapin, M

    2015-01-01T23:59:59.000Z

    Pure tungsten or its alloys(WHA) find applications in several fields, especially due to the fact that these materials show a good combination of mechanical and thermal properties and they are commonly used in aerospace, automotive, metal working processes, military and nuclear technologies. Looking at the scientific literature, a lack in the mechanical characterization over wide ranges in temperature and strain-rates was found, especially forW–Ni–Cu alloys.

  1. Pulmonary toxicity after exposure to military-relevant heavy metal tungsten alloy particles

    SciTech Connect (OSTI)

    Roedel, Erik Q., E-mail: Erik.Roedel@amedd.army.mil [Department of General Surgery, Tripler Army Medical Center, Honolulu, HI 96859 (United States); Cafasso, Danielle E., E-mail: Danielle.Cafasso@amedd.army.mil [Department of General Surgery, Tripler Army Medical Center, Honolulu, HI 96859 (United States); Lee, Karen W.M., E-mail: Karen.W.Lee@amedd.army.mil [Department of Clinical Investigation, Tripler Army Medical Center, Honolulu, HI 96859 (United States); Pierce, Lisa M., E-mail: Lisa.Pierce@amedd.army.mil [Department of Clinical Investigation, Tripler Army Medical Center, Honolulu, HI 96859 (United States)

    2012-02-15T23:59:59.000Z

    Significant controversy over the environmental and public health impact of depleted uranium use in the Gulf War and the war in the Balkans has prompted the investigation and use of other materials including heavy metal tungsten alloys (HMTAs) as nontoxic alternatives. Interest in the health effects of HMTAs has peaked since the recent discovery that rats intramuscularly implanted with pellets containing 91.1% tungsten/6% nickel/2.9% cobalt rapidly developed aggressive metastatic tumors at the implantation site. Very little is known, however, regarding the cellular and molecular mechanisms associated with the effects of inhalation exposure to HMTAs despite the recognized risk of this route of exposure to military personnel. In the current study military-relevant metal powder mixtures consisting of 92% tungsten/5% nickel/3% cobalt (WNiCo) and 92% tungsten/5% nickel/3% iron (WNiFe), pure metals, or vehicle (saline) were instilled intratracheally in rats. Pulmonary toxicity was assessed by cytologic analysis, lactate dehydrogenase activity, albumin content, and inflammatory cytokine levels in bronchoalveolar lavage fluid 24 h after instillation. The expression of 84 stress and toxicity-related genes was profiled in lung tissue and bronchoalveolar lavage cells using real-time quantitative PCR arrays, and in vitro assays were performed to measure the oxidative burst response and phagocytosis by lung macrophages. Results from this study determined that exposure to WNiCo and WNiFe induces pulmonary inflammation and altered expression of genes associated with oxidative and metabolic stress and toxicity. Inhalation exposure to both HMTAs likely causes lung injury by inducing macrophage activation, neutrophilia, and the generation of toxic oxygen radicals. -- Highlights: ? Intratracheal instillation of W–Ni–Co and W–Ni–Fe induces lung inflammation in rats. ? W–Ni–Co and W–Ni–Fe alter expression of oxidative stress and toxicity genes. ? W–Ni–Co induces a greater oxidative burst response than W–Ni–Fe in lung macrophages.

  2. Method for determining the hardness of strain hardening articles of tungsten-nickel-iron alloy

    DOE Patents [OSTI]

    Wallace, Steven A. (Knoxville, TN)

    1984-01-01T23:59:59.000Z

    The present invention is directed to a rapid nondestructive method for determining the extent of strain hardening in an article of tungsten-nickel-iron alloy. The method comprises saturating the article with a magnetic field from a permanent magnet, measuring the magnetic flux emanating from the article, comparing the measurements of the magnetic flux emanating from the article with measured magnetic fluxes from similarly shaped standards of the alloy with known amounts of strain hardening to determine the hardness.

  3. ACHIEVING THE REQUIRED COOLANT FLOW DISTRIBUTION FOR THE ACCELERATOR PRODUCTION OF TRITIUM (APT) TUNGSTEN NEUTRON SOURCE

    SciTech Connect (OSTI)

    D. SIEBE; K. PASAMEHMETOGLU

    2000-11-01T23:59:59.000Z

    The Accelerator Production of Tritium neutron source consists of clad tungsten targets, which are concentric cylinders with a center rod. These targets are arranged in a matrix of tubes, producing a large number of parallel coolant paths. The coolant flow required to meet thermal-hydraulic design criteria varies with location. This paper describes the work performed to ensure an adequate coolant flow for each target for normal operation and residual heat-removal conditions.

  4. Stability of very-high pressure arc discharges against perturbations of the electron temperature

    SciTech Connect (OSTI)

    Benilov, M. S. [Departamento de Fisica, Ciencias Exactas e Engenharia, Universidade da Madeira, Largo do Municipio, Funchal 9000 (Portugal); Hechtfischer, U. [Philips Lighting, BU Automotive Lamps, Technology, Philipsstrasse 8, Aachen 52068 (Germany)

    2012-04-01T23:59:59.000Z

    We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.

  5. Enhanced photoelectrochemical properties of TiO{sub 2} by codoping with tungsten and silver

    SciTech Connect (OSTI)

    Khan, Matiullah, E-mail: matiullahustb@gmail.com [Department of Inorganic Nonmetallic Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Department of Physics, Kohat University of Science and Technology (KUST), Kohat 26000 (Pakistan); Jiang, Peng; Cao, Wenbin, E-mail: wbcao@ustb.edu.cn [Department of Inorganic Nonmetallic Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Li, Jing [State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083 (China)

    2014-04-21T23:59:59.000Z

    The Tungsten (W) and Silver (Ag) codoped TiO{sub 2} samples were successfully synthesized by hydrothermal method without any post calcination. To understand the correlation between electronic structure and photocatalytic properties, the synthesized samples were characterized using X-ray diffraction, Brunauer–Emmett–Teller specific surface area, transmission electron microscopy, ultra-violet–visible absorption spectra, and X-ray photoelectron spectroscopy (XPS), and the photocatalytic properties were evaluated under visible light irradiations. Codoping could not induce any changes in the phase and all the synthesized samples displayed pure anatase phase with spherical morphology. Visible light absorptions of the codoped samples were dramatically improved compared to the corresponding mono-doped samples. XPS analysis indicated that the dopant atoms successfully entered the TiO{sub 2} network. Results from the visible light photodegradation experiments showed that tungsten-silver codoped TiO{sub 2} possessed strong ability in photo-degrading methylene blue compared to tungsten doped TiO{sub 2} and silver doped TiO{sub 2}, which was attributed to the smaller particle size, higher specific surface area, enhanced visible light absorption, and improved separation of photogenerated carriers.

  6. Growth of tungsten nanoparticles in direct-current argon glow discharges

    SciTech Connect (OSTI)

    Kishor Kumar, K.; Coueedel, L.; Arnas, C. [Laboratoire de Physique des Interactions Ioniques et Moleculaires, CNRS-Aix-Marseille Universite, 13397 Marseille (France)

    2013-04-15T23:59:59.000Z

    The growth of nanoparticles from the sputtering of a tungsten cathode in DC argon glow discharges is reported. The study was performed at fixed argon pressure and constant discharge current. The growth by successive agglomerations is evidenced. First, tungsten nanocrystallites agglomerate into primary particles, the most probable size of which being {approx}30 nm. Primary particles of this size are observed for all plasma durations and always remain the most numerous in the discharge. Primary particles quickly agglomerate to form particles with size up to {approx}150 nm. For short plasma duration, log-normal functions describe accurately the dust particle size distributions. On the contrary, for long discharge durations, a second hump appears in the distributions toward large particle sizes. In the meantime, the discharge voltage, electron density, and emission line intensities strongly evolve. Their evolutions can be divided in four separate phases and exhibit unusual distinctive features compared to earlier observations in discharges in which particles were growing. The evolution of the different parameters is explained by a competition between the surface state of the tungsten cathode and the influence of the growing nanoparticles. The differences with sputtering glow discharges and chemically active plasmas suggest that the nanoparticle growth and its influence on discharge parameters is system and material dependent.

  7. Effect of tungsten crystallographic orientation on He-ion-induced surface morphology changes

    SciTech Connect (OSTI)

    Parish, Chad M [ORNL; Hijazi, Hussein Dib [ORNL; Meyer III, Harry M [ORNL; Meyer, Fred W [ORNL

    2014-01-01T23:59:59.000Z

    In order to study the early stages of nanofuzz growth in fusion-plasma-facing tungsten, mirror-polished high-purity tungsten was exposed to 80 eV helium at 1130 C to a fluence of 4 1024 He/m2. The previously smooth surface shows morphology changes, and grains form one of four qualitatively different morphologies: smooth, wavy, pyramidal, or terraced/wide waves. Combining high-resolution scanning electron microscopy (SEM) observations to determine the morphology of each grain with quantitative measurement of the grain's orientation via electron backscatter diffraction (EBSD) in SEM shows that the normal-direction crystallographic orientation of the underlying grain controls the growth morphology. Specifically, near-<001> || normal direction (ND) grains formed pyramids, near-<114> to <112> || ND grains formed wavy and stepped structures, and near-<103> || ND grains remained smooth. Comparisons to control specimens indicate no changes to underlying bulk crystallographic texture, and the effects are attributed to surface energy anisotropy, although, surprisingly, the expected {101} low-energy planes were not the most stable. Future developments to control tungsten texture via thermomechanical processing, ideally obtaining a sharp near- <103> || ND processing texture, may delay the formation of nanofuzz.

  8. Measurements of the Time Structure of Hadronic Showers in a Scintillator-Tungsten HCAL

    E-Print Network [OSTI]

    Frank Simon; for the CALICE Collaboration

    2011-09-15T23:59:59.000Z

    For calorimeter applications requiring precise time stamping, the time structure of hadronic showers in the detector is a crucial issue. This applies in particular to detector concepts for CLIC, where a hadronic calorimeter with tungsten absorbers is being considered to achieve a high level of shower containment while satisfying strict space constraints. The high hadronic background from gamma gamma to hadrons processes at 3 TeV in combination with the 2 GHz bunch crossing frequency at CLIC requires good time stamping in the detectors. To provide first measurements of the time structure in a highly granular scintillator-tungsten calorimeter, T3B, a dedicated timing experiment, was installed behind the last layer of the CALICE WHCAL prototype, a 30 layer tungsten scintillator calorimeter. T3B consists of 15 small scintillator cells with embedded silicon photomultipliers, read out with fast digitizers over a time window of 2.4 us, and provides detailed measurements of the time structure of the signal. The offline data reconstruction performs an automatic gain calibration using noise events recorded between physics triggers and allows the determination of the arrival time of each photon at the photon sensor. The T3B setup, its calibration and data reconstruction, as well as first results of the time structure of the calorimeter response for 10 GeV pions recorded at the CERN PS confronted with Geant4 simulations using different physics lists are discussed.

  9. Study of electrodeposited nickel-molybdenum, nickel-tungsten, cobalt-molybdenum, and cobalt-tungsten as hydrogen electrodes in alkaline water electrolysis

    SciTech Connect (OSTI)

    Fan, C.; Piron, D.L.; Sleb, A.; Paradis, P. (Ecole Polytechnique de Montreal, Quebec (Canada). Dept. de Metallurgie et de Genie des Materiaux)

    1994-02-01T23:59:59.000Z

    Electrodeposited nickel-molybdenum, nickel-tungsten, cobalt-molybdenum, and cobalt-tungsten were characterized for the hydrogen evolution reaction (HER) in the electrolysis of 30 w/o KOH alkaline water at 25 C. The rate-determining step (rds) of the HER was suggested based on the Tafel slope of polarization and the capacitance of electrode-solution interface determined by ac impedance measurement. The HER on the nickel- and cobalt-based codeposits was enhanced significantly compared with that o the electrolytic nickel and cobalt with comparable deposit loadings. The decrease in the HER overpotential was more pronounced on the molybdenum-containing codeposits, particularly on cobalt-molybdenum which also showed a high stability. The enhancement of the HER was attributed to both the synergetic composition and the increased active surface of the codeposits. The real electrocatalytic activity of te electrodes and the effect of their and the increased active surface of the codeposits. The real electrocatalytic activity of the electrodes and the effect of their surface increase were distinguished quantitatively. The linear relations between HER overpotential and surface roughness factor of the electrodes on a Y-log(X) plot were obtained experimentally and interpreted based on the Tafel law.

  10. A study of tungsten spectra using large helical device and compact electron beam ion trap in NIFS

    SciTech Connect (OSTI)

    Morita, S.; Goto, M.; Murakami, I. [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292, Gifu (Japan); Dong, C. F.; Kato, D.; Sakaue, H. A.; Oishi, T. [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Koike, F. [Physics Laboratory, School of Medicine, Kitasato University, Sagamihara 252-0374 (Japan); Nakamura, N. [Institute of Laser Science, University of Electro-Communications, Tokyo 182-8585 (Japan); Sasaki, A. [Quantum Beam Science Directorate, Japan Atomic Energy Research Agency, Kizugawa 619-0215, Kyoto (Japan); Wang, E. H. [Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292, Gifu (Japan)

    2013-07-11T23:59:59.000Z

    Tungsten spectra have been observed from Large Helical Device (LHD) and Compact electron Beam Ion Trap (CoBIT) in wavelength ranges of visible to EUV. The EUV spectra with unresolved transition array (UTA), e.g., 6g-4f, 5g-4f, 5f-4d and 5p-4d transitions for W{sup +24-+33}, measured from LHD plasmas are compared with those measured from CoBIT with monoenergetic electron beam ({<=}2keV). The tungsten spectra from LHD are well analyzed based on the knowledge from CoBIT tungsten spectra. The C-R model code has been developed to explain the UTA spectra in details. Radial profiles of EUV spectra from highly ionized tungsten ions have been measured and analyzed by impurity transport simulation code with ADPAK atomic database code to examine the ionization balance determined by ionization and recombination rate coefficients. As the first trial, analysis of the tungsten density in LHD plasmas is attempted from radial profile of Zn-like WXLV (W{sup 44+}) 4p-4s transition at 60.9A based on the emission rate coefficient calculated with HULLAC code. As a result, a total tungsten ion density of 3.5 Multiplication-Sign 10{sup 10}cm{sup -3} at the plasma center is reasonably obtained. In order to observe the spectra from tungsten ions in lower-ionized charge stages, which can give useful information on the tungsten influx in fusion plasmas, the ablation cloud of the impurity pellet is directly measured with visible spectroscopy. A lot of spectra from neutral and singly ionized tungsten are observed and some of them are identified. A magnetic forbidden line from highly ionized tungsten ions has been examined and Cd-like WXXVII (W{sup 26+}) at 3893.7A is identified as the ground-term fine-structure transition of 4f{sup 23}H{sub 5}-{sup 3}H{sub 4}. The possibility of {alpha} particle diagnostic in D-T burning plasmas using the magnetic forbidden line is discussed.

  11. The use of RapidArc volumetric-modulated arc therapy to deliver stereotactic radiosurgery and stereotactic body radiotherapy to intracranial and extracranial targets

    SciTech Connect (OSTI)

    Roa, Dante E., E-mail: droa@uci.edu [Department of Radiation Oncology, Chao Family Comprehensive Cancer Center, University of California, Irvine-Medical Center, Orange, CA (United States); Schiffner, Daniel C.; Zhang Juying; Dietrich, Salam N.; Kuo, Jeffrey V.; Wong, Jason; Ramsinghani, Nilam S.; Al-Ghazi, Muthana S.A.L. [Department of Radiation Oncology, Chao Family Comprehensive Cancer Center, University of California, Irvine-Medical Center, Orange, CA (United States)

    2012-10-01T23:59:59.000Z

    Twenty-three targets in 16 patients treated with stereotactic radiosurgery (SRS) or stereotactic body radiotherapy (SBRT) were analyzed in terms of dosimetric homogeneity, target conformity, organ-at-risk (OAR) sparing, monitor unit (MU) usage, and beam-on time per fraction using RapidArc volumetric-modulated arc therapy (VMAT) vs. multifield sliding-window intensity-modulated radiation therapy (IMRT). Patients underwent computed tomography simulation with site-specific immobilization. Magnetic resonance imaging fusion and optical tracking were incorporated as clinically indicated. Treatment planning was performed using Eclipse v8.6 to generate sliding-window IMRT and 1-arc and 2-arc RapidArc plans. Dosimetric parameters used for target analysis were RTOG conformity index (CI{sub RTOG}), homogeneity index (HI{sub RTOG}), inverse Paddick Conformity Index (PCI), D{sub mean} and D5-D95. OAR sparing was analyzed in terms of D{sub max} and D{sub mean}. Treatment delivery was evaluated based on measured beam-on times delivered on a Varian Trilogy linear accelerator and recorded MU values. Dosimetric conformity, homogeneity, and OAR sparing were comparable between IMRT, 1-arc RapidArc and 2-arc RapidArc plans. Mean beam-on times {+-} SD for IMRT and 1-arc and 2-arc treatments were 10.5 {+-} 7.3, 2.6 {+-} 1.6, and 3.0 {+-} 1.1 minutes, respectively. Mean MUs were 3041, 1774, and 1676 for IMRT, 1-, and 2-arc plans, respectively. Although dosimetric conformity, homogeneity, and OAR sparing were similar between these techniques, SRS and SBRT fractions treated with RapidArc were delivered with substantially less beam-on time and fewer MUs than IMRT. The rapid delivery of SRS and SBRT with RapidArc improved workflow on the linac with these otherwise time-consuming treatments and limited the potential for intrafraction organ and patient motion, which can cause significant dosimetric errors. These clinically important advantages make image-guided RapidArc useful in the delivery of SRS and SBRT to intracranial and extracranial targets.

  12. DIVIMP Tungsten Erosion and Transport Simulations of an ELM Cycle in a JET Type-I ELMy H-mode Plasma

    E-Print Network [OSTI]

    DIVIMP Tungsten Erosion and Transport Simulations of an ELM Cycle in a JET Type-I ELMy H-mode Plasma

  13. Influence of Atomic Physics on EDGE2D-EIRENE Simulations of JET Divertor Detachment with Carbon and Beryllium/Tungsten Plasma-Facing Components

    E-Print Network [OSTI]

    Influence of Atomic Physics on EDGE2D-EIRENE Simulations of JET Divertor Detachment with Carbon and Beryllium/Tungsten Plasma-Facing Components

  14. Impact of the Carbon and Tungsten Wall Materials on Deuterium Recycling and Neutral Fuelling in JET using EDGE2D/EIRENE

    E-Print Network [OSTI]

    Impact of the Carbon and Tungsten Wall Materials on Deuterium Recycling and Neutral Fuelling in JET using EDGE2D/EIRENE

  15. Target Particle and Heat Loads in Low-Triangularity L-mode Plasmas in JET with Carbon and Beryllium/Tungsten Walls

    E-Print Network [OSTI]

    Target Particle and Heat Loads in Low-Triangularity L-mode Plasmas in JET with Carbon and Beryllium/Tungsten Walls

  16. EFFECTS OF B, C, N, O, P AND S IMPURITIES ON TUNGSTEN ?27[110]{552} AND ?3[110]{112} GRAIN BOUNDARIES

    SciTech Connect (OSTI)

    Setyawan, Wahyu; Kurtz, Richard J.

    2013-04-01T23:59:59.000Z

    The objective of this research is to support the design of tungsten-based materials with increased fracture resistance using first-principles computational methods.

  17. Simulation of Tungsten Sputtering with EDGE2D-EIRENE in Low Triangularity L-Mode JET ITER-Like Wall Configuration

    E-Print Network [OSTI]

    Simulation of Tungsten Sputtering with EDGE2D-EIRENE in Low Triangularity L-Mode JET ITER-Like Wall Configuration

  18. A Bulk Tungsten Tile for JET: Derivation of Power-Handling Performance and Validation of the Thermal Model, in the MARION Facility

    E-Print Network [OSTI]

    A Bulk Tungsten Tile for JET: Derivation of Power-Handling Performance and Validation of the Thermal Model, in the MARION Facility

  19. MAGENCO: A map generalization controller for Arc/Info

    SciTech Connect (OSTI)

    Ganter, J.H.; Cashwell, J.W.

    1994-06-01T23:59:59.000Z

    The Arc/Info GENERALIZE command implements the Douglas-Peucker algorithm, a well-regarded approach that preserves line ``character`` while reducing the number of points according to a tolerance parameter supplied by the user. The authors have developed an Arc Macro Language (AML) interface called MAGENCO that allows the user to browse workspaces, select a coverage, extract a sample from this coverage, then apply various tolerances to the sample. The results are shown in multiple display windows that are arranged around the original sample for quick visual comparison. The user may then return to the whole coverage and apply the chosen tolerance. They analyze the ergonomics of line simplification, explain the design (which includes an animated demonstration of the Douglas-Peucker algorithm), and discuss key points of the MAGENCO implementation.

  20. Vacuum Arc Ion Sources: Recent Developments and Applications

    SciTech Connect (OSTI)

    Brown, Ian; Oks, Efim

    2005-05-01T23:59:59.000Z

    The vacuum arc ion source has evolved over the past twenty years into a standard laboratory tool for the production of high current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. The primary application of this kind of source has evolved to be ion implantation for material surface modification. Another important use is for injection of high current beams of heavy metal ions into the front ends of particle accelerators, and much excellent work has been carried out in recent years in optimizing the source for reliable accelerator application. The source also provides a valuable tool for the investigation of the fundamental plasma physics of vacuum arc plasma discharges. As the use of the source has grown and diversified, at the same time the ion source performance and operational characteristics have been improved in a variety of different ways also. Here we review the growth and status of vacuum arc ion sources around the world, and summarize some of the applications for which the sources have been used.

  1. High temperature coatings for gas turbines

    DOE Patents [OSTI]

    Zheng, Xiaoci Maggie

    2003-10-21T23:59:59.000Z

    Coating for high temperature gas turbine components that include a MCrAlX phase, and an aluminum-rich phase, significantly increase oxidation and cracking resistance of the components, thereby increasing their useful life and reducing operating costs. The aluminum-rich phase includes aluminum at a higher concentration than aluminum concentration in the MCrAlX alloy, and an aluminum diffusion-retarding composition, which may include cobalt, nickel, yttrium, zirconium, niobium, molybdenum, rhodium, cadmium, indium, cerium, iron, chromium, tantalum, silicon, boron, carbon, titanium, tungsten, rhenium, platinum, and combinations thereof, and particularly nickel and/or rhenium. The aluminum-rich phase may be derived from a particulate aluminum composite that has a core comprising aluminum and a shell comprising the aluminum diffusion-retarding composition.

  2. Influence of tungsten substitution and oxygen deficiency on the thermoelectric properties of CaMnO{sub 3??}

    SciTech Connect (OSTI)

    Thiel, Philipp; Eilertsen, James; Populoh, Sascha, E-mail: sascha.populoh@empa.ch; Saucke, Gesine; Shkabko, Andrey; Sagarna, Leyre; Karvonen, Lassi [Laboratory for Solid State Chemistry and Catalysis, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Döbeli, Max [Ion Beam Physics, Schafmattstrasse 20, ETH Hönggerberg, Swiss Federal Institute of Technology, CH-8093 Zürich (Switzerland); Weidenkaff, Anke [Laboratory for Solid State Chemistry and Catalysis, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Materials Chemistry, Institute for Materials Science, University of Stuttgart, Heisenbergstr. 3, DE-70569 Stuttgart (Germany)

    2013-12-28T23:59:59.000Z

    Polycrystalline tungsten-substituted CaMn{sub 1?x}W{sub x}O{sub 3??} (0.00???x???0.05) powders were synthesized from a polymeric precursor, pressed and sintered to high density. The impact of tungsten substitution on the crystal structure, thermal stability, phase transition, electronic and thermal transport properties is assessed. Tungsten acts as an electron donator and strongly affects high-temperature oxygen stoichiometry. Oxygen vacancies form in the high figure-of-merit (ZT)-region starting from about T?=?1000?K and dominate the carrier concentration and electronic transport far more than the tungsten substitution. The analysis of the transport properties yields that in the investigated regime the band filling is sufficiently high to overcome barriers of polaron transport. Therefore, the Cutler-Mott approach describes the electrical transport more accurately than the Mott approach for small polaron transport. The lattice thermal conductivity near room temperature is strongly suppressed with increasing tungsten concentration due to mass-difference impurity scattering. A ZT of 0.25 was found for x?=?0.04 at 1225?K.

  3. Synthesis and studies of molybdenum and tungsten complexes for dinitrogen reduction

    E-Print Network [OSTI]

    Chin, Jia Min

    2010-01-01T23:59:59.000Z

    A series of monopyrroletriamine ligands [Arpyr(Ar')2]H3 of the form ArC4H2NHCH2N(CH2CH2NHAr')2 (Ar = 2,4,6-mesityl (Mes), 2,4,6-triisopropylphenyl (TRIP); Ar' = C6F5, 2-tolyl (o-tol), naphthyl, 3,5-(2,4,6-triisopropylphenyl)phenyl ...

  4. The Effect of 800 MeV Proton Irradiation on the Mechanical Properties of Tungsten at Room Temperature and at 475 Degrees C

    SciTech Connect (OSTI)

    Maloy, S A.; James, M R.; Sommer, Walter F.; Willcutt, Gordon; Lopez, M; Romero, T J.; Toloczko, Mychailo B.

    2005-08-01T23:59:59.000Z

    For the accelerator production of tritium (APT), the accelerator driven transmutation facility (ADTF), and the advanced fuel cycle initiative (AFCI), tungsten is being proposed as a target material to produce neutrons. In this study, tungsten rods were irradiated at the 800MeV Los Alamos Neutron Science Center (LANSCE) proton accelerator for six months.

  5. Dielectric and photovoltaic phenomena in tungsten-doped Pb,,Mg1/3Nb2/3...1-xTixO3 crystal

    E-Print Network [OSTI]

    Dielectric and photovoltaic phenomena in tungsten-doped Pb,,Mg1/3Nb2/3...1-xTixO3 crystal Chi. The tungsten-doped Pb1-xLax ZryTiz 1-x/4O3 ceramics, i.e., PLZT x/y/z , exhibits a large photovoltaic ef- fect

  6. A Solid-State NMR Study of Tungsten Methyl Group Dynamics in [W(5-C5Me5)Me4][PF6

    E-Print Network [OSTI]

    Griffin, Robert G.

    A Solid-State NMR Study of Tungsten Methyl Group Dynamics in [W(5-C5Me5)Me4][PF6] Douglas C. Maus Spinning (MAS) 13C and static 2H NMR studies of the dynamics of the methyl groups coordinated to tungsten

  7. Radiation-Damage Study of a Monocrystalline Tungsten Positron Converter X. Artru, R. Kirsch, IPN, Lyon, France; R. Chehab, LAL, Orsay, France;

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Radiation-Damage Study of a Monocrystalline Tungsten Positron Converter X. Artru, R. Kirsch, IPN tested on a 0.3 mm thick tungsten monocrystal exposed dur- ing 6 months to the 30 Gev incident electron and the corresponding enhancement in pair production [1, 3]. Their use in linear colliders (LC), where high beam

  8. Gas metal arc welding of duplex stainless steel using flux cored wire

    SciTech Connect (OSTI)

    Maruyama, T.; Ogawa, T.; Nishiyama, S.; Ushijima, A.; Yamashita, K. [Kobe Steel, Ltd., Fujisawa (Japan)

    1994-12-31T23:59:59.000Z

    The effect of chemical compositions and welding parameters on pitting corrosion resistance and notch toughness of duplex stainless steel weld metals by FCAW was investigated. And the effect of welding parameters on hot cracking susceptibility of the FCAW weld metals was also studied. Pitting corrosion resistance was improved with the increase of Cr, Mo and N content in the weld metal, and it was also proved that the corrosion resistance was greatly affected by welding heat input. Hot cracking susceptibility of the weld metal was increased with the increase of welding current and welding speed.

  9. Structure and seismic stratigraphy of the Bonin Trench-Arc system

    E-Print Network [OSTI]

    Bandy, William Lee

    1982-01-01T23:59:59.000Z

    . An oblique collision between Japan and the Bonin Arc during the opening of the Japan Sea both compressed the arc and induced a clockwise torque along the northern margin of the arc which bent and fractured the arc, forming the en-echelon structures.... Cartoon illustrating three possible mechanisms for faulting and subsidence of the inner trench slope 108 Fig. 47. Development history of the forearc region of the Japan System off northern Honshu 112 Fig. 48. Trends of the en-echelon features...

  10. Phases and domain structures in tungsten-doped Pb,,Mg1/3Nb2/3...1-xTixO3 ,,x=0.35... crystal

    E-Print Network [OSTI]

    Phases and domain structures in tungsten-doped Pb,,Mg1/3Nb2/3...1-xTixO3 ,,x=0.35... crystal F and piezoelectric response, has the great potential of applications in wireless photoactuators. The tungsten ferroelectric physics of tungsten-doped PMNT single crystals is still unclear. In this study, temperature

  11. ANALYSIS OF A CLAD TUNGSTEN TARGET AFTER IRRADIATION IN AN 800 MeV PROTON BEAM S.A. Maloy, M.R. James, W.F. Sommer jr.,

    E-Print Network [OSTI]

    McDonald, Kirk

    Production of Tritium (APT) and the Accelerator Driven Transmutation Facility (ADTF), tungsten is beingANALYSIS OF A CLAD TUNGSTEN TARGET AFTER IRRADIATION IN AN 800 MeV PROTON BEAM S.A. Maloy, M of tungsten are degraded from irradiation in a neutron flux but little work had been performed

  12. Shock-less interactions of ablation streams in tungsten wire array z-pinches

    SciTech Connect (OSTI)

    Swadling, G. F.; Lebedev, S. V.; Hall, G. N.; Suzuki-Vidal, F.; Burdiak, G.; Harvey-Thompson, A. J.; Bland, S. N.; De Grouchy, P.; Khoory, E.; Pickworth, L.; Skidmore, J.; Suttle, L. [The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom)] [The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom)

    2013-06-15T23:59:59.000Z

    Shock-less dynamics were observed during the ablation phase in tungsten wire array experiments carried out on the 1.4 MA, 240 ns MAGPIE generator at Imperial College London. This behaviour contrasts with the shock structures which were seen to dominate in previous experiments on aluminium arrays [Swadling et al., Phys. Plasmas 20, 022705 (2013)]. In this paper, we present experimental results and make comparisons both with calculations of the expected mean free paths for collisions between the ablation streams and with previously published Thomson scattering measurements of the plasma parameters in these arrays [Harvey-Thompson et al., Phys. Plasmas 19, 056303 (2012)].

  13. Testing Hadronic Interaction Models using a Highly Granular Silicon-Tungsten Calorimeter

    E-Print Network [OSTI]

    Bilki, B; Schlereth, J; Xia, L; Deng, Z; Li, Y; Wang, Y; Yue, Q; Yang, Z; Eigen, G; Mikami, Y; Price, T; Watson, N K; Thomson, M A; Ward, D R; Benchekroun, D; Hoummada, A; Khoulaki, Y; Cârloganu, C; Chang, S; Khan, A; Kim, D H; Kong, D J; Oh, Y D; Blazey, G C; Dyshkant, A; Francis, K; Lima, J G R; Salcido, P; Zutshi, V; Boisvert, V; Green, B; Misiejuk, A; Salvatore, F; Kawagoe, K; Miyazaki, Y; Sudo, Y; Suehara, T; Tomita, T; Ueno, H; Yoshioka, T; Apostolakis, J; Folger, G; Ivantchenko, V; Ribon, A; Uzhinskiy, V; Cauwenbergh, S; Tytgat, M; Zaganidis, N; Hostachy, J -Y; Morin, L; Gadow, K; Göttlicher, P; Günter, C; Krüger, K; Lutz, B; Reinecke, M; Sefkow, F; Feege, N; Garutti, E; Laurien, S; Lu, S; Marchesini, I; Matysek, M; Ramilli, M; Kaplan, A; Norbeck, E; Northacker, D; Onel, Y; Kim, E J; van Doren, B; Wilson, G W; Wing, M; Bobchenko, B; Chadeeva, M; Chistov, R; Danilov, M; Drutskoy, A; Epifantsev, A; Markin, O; Mizuk, R; Novikov, E; Popov, V; Rusinov, V; Tarkovsky, E; Besson, D; Popova, E; Gabriel, M; Kiesling, C; Simon, F; Soldner, C; Szalay, M; Tesar, M; Weuste, L; Amjad, M S; Bonis, J; Callier, S; di Lorenzo, S Conforti; Cornebise, P; Doublet, Ph; Dulucq, F; Faucci-Giannelli, M; Fleury, J; Frisson, T; Kégl, B; van der Kolk, N; Li, H; Martin-Chassard, G; Richard, F; de la Taille, Ch; Pöschl, R; Raux, L; Rouëné, J; Seguin-Moreau, N; Anduze, M; Balagura, V; Becheva, E; Boudry, V; Brient, J-C; Cornat, R; Frotin, M; Gastaldi, F; Magniette, F; Matthieu, A; de Freitas, P Mora; Videau, H; Augustin, J-E; David, J; Ghislain, P; Lacour, D; Lavergne, L; Zacek, J; Cvach, J; Gallus, P; Havranek, M; Janata, M; Kvasnicka, J; Lednicky, D; Marcisovsky, M; Polak, I; Popule, J; Tomasek, L; Tomasek, M; Ruzicka, P; Sicho, P; Smolik, J; Vrba, V; Zalesak, J; Jeans, D; Götze, M

    2014-01-01T23:59:59.000Z

    A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 600,000 selected negatively changed pion events at energies between 2 and 10 GeV have been studied. The predictions of several physics models available within the GEANT4 simulation tool kit are compared to this data. Although a reasonable overall description of the data is observed, there are significant quantitative discrepancies in the longitudinal and transverse distributions of reconstructed energy.

  14. Study of the interactions of pions in the CALICE silicon-tungsten calorimeter prototype

    E-Print Network [OSTI]

    C. Adloff; Y. Karyotakis; J. Repond; J. Yu; G. Eigen; Y. Mikami; N. K. Watson; J. A. Wilson; T. Goto; G. Mavromanolakis; M. A. Thomson; D. R. Ward; W. Yan; D. Benchekroun; A. Hoummada; Y. Khoulaki; J. Apostolakis; A. Ribon; V. Uzhinskiy; M. Benyamna; C. Cârloganu; F. Fehr; P. Gay; G. C. Blazey; D. Chakraborty; A. Dyshkant; K. Francis; D. Hedin; J. G. Lima; V. Zutshi; J. -Y. Hostachy; K. Krastev; L. Morin; N. D'Ascenzo; U. Cornett; D. David; R. Fabbri; G. Falley; K. Gadow; E. Garutti; P. Göttlicher; T. Jung; S. Karstensen; A. -I. Lucaci-Timoce; B. Lutz; N. Meyer; V. Morgunov; M. Reinecke; F. Sefkow; P. Smirnov; A. Vargas-Trevino; N. Wattimena; O. Wendt; N. Feege; M. Groll; J. Haller; R. -D. Heuer; S. Morozov; S. Richter; J. Samson; A. Kaplan; H. -Ch. Schultz-Coulon; W. Shen; A. Tadday; B. Bilki; E. Norbeck; Y. Onel; E. J. Kim; G. Kim; D-W. Kim; K. Lee; S. C. Lee; K. Kawagoe; Y. Tamura; P. D. Dauncey; A. -M. Magnan; H. Yilmaz; O. Zorba; V. Bartsch; M. Postranecky; M. Warren; M. Wing; M. G. Green; F. Salvatore; M. Bedjidian; R. Kieffer; I. Laktineh; M. -C. Fouz; D. S. Bailey; R. J. Barlow; M. Kelly; R. J. Thompson; M. Danilov; E. Tarkovsky; N. Baranova; D. Karmanov; M. Korolev; M. Merkin; A. Voronin; A. Frey; S. Lu; K. Seidel; F. Simon; C. Soldner; L. Weuste; J. Bonis; B. Bouquet; S. Callier; P. Cornebise; Ph. Doublet; M. Faucci Giannelli; J. Fleury; H. Li; G. Martin-Chassard; F. Richard; Ch. de la Taille; R. Poeschl; L. Raux; N. Seguin-Moreau; F. Wicek; M. Anduze; V. Boudry; J-C. Brient; G. Gaycken; D. Jeans; P. Mora de Freitas; G. Musat; M. Reinhard; A. Rougé; M. Ruan; J-Ch. Vanel; H. Videau; K-H. Park; J. Zacek; J. Cvach; P. Gallus; M. Havranek; M. Janata; M. Marcisovsky; I. Polak; J. Popule; L. Tomasek; M. Tomasek; P. Ruzicka; P. Sicho; J. Smolik; V. Vrba; J. Zalesak; B. Belhorma; M. Belmir; S. W. Nam; I. H. Park; J. Yang; Jong-Seo Chai; Jong-Tae Kim; Geun-Bum Kim; J. Kang; Y. -J. Kwon

    2010-04-28T23:59:59.000Z

    A prototype silicon-tungsten electromagnetic calorimeter for an ILC detector was tested in 2007 at the CERN SPS test beam. Data were collected with electron and hadron beams in the energy range 8 to 80 GeV. The analysis described here focuses on the interactions of pions in the calorimeter. One of the main objectives of the CALICE program is to validate the Monte Carlo tools available for the design of a full-sized detector. The interactions of pions in the Si-W calorimeter are therefore confronted with the predictions of various physical models implemented in the GEANT4 simulation framework.

  15. Testing Hadronic Interaction Models using a Highly Granular Silicon-Tungsten Calorimeter

    E-Print Network [OSTI]

    The CALICE Collaboration; B. Bilki; J. Repond; J. Schlereth; L. Xia; Z. Deng; Y. Li; Y. Wang; Q. Yue; Z. Yang; G. Eigen; Y. Mikami; T. Price; N. K. Watson; M. A. Thomson; D. R. Ward; D. Benchekroun; A. Hoummada; Y. Khoulaki; C. Cârloganu; S. Chang; A. Khan; D. H. Kim; D. J. Kong; Y. D. Oh; G. C. Blazey; A. Dyshkant; K. Francis; J. G. R. Lima; P. Salcido; V. Zutshi; V. Boisvert; B. Green; A. Misiejuk; F. Salvatore; K. Kawagoe; Y. Miyazaki; Y. Sudo; T. Suehara; T. Tomita; H. Ueno; T. Yoshioka; J. Apostolakis; G. Folger; G. Folger; V. Ivantchenko; A. Ribon; V. Uzhinskiy; S. Cauwenbergh; M. Tytgat; N. Zaganidis; J. -Y. Hostachy; L. Morin; K. Gadow; P. Göttlicher; C. Günter; K. Krüger; B. Lutz; M. Reinecke; F. Sefkow; N. Feege; E. Garutti; S. Laurien; S. Lu; I. Marchesini; M. Matysek; M. Ramilli; A. Kaplan; E. Norbeck; D. Northacker; Y. Onel; E. J. Kim; B. van Doren; G. W. Wilson; M. Wing; B. Bobchenko; M. Chadeeva; R. Chistov; M. Danilov; A. Drutskoy; A. Epifantsev; O. Markin; R. Mizuk; E. Novikov; V. Popov; V. Rusinov; E. Tarkovsky; D. Besson; E. Popova; M. Gabriel; C. Kiesling; F. Simon; C. Soldner; M. Szalay; M. Tesar; L. Weuste; M. S. Amjad; J. Bonis; S. Callier; S. Conforti di Lorenzo; P. Cornebise; Ph. Doublet; F. Dulucq; M. Faucci-Giannelli; J. Fleury; T. Frisson; B. Kégl; N. van der Kolk; H. Li; G. Martin-Chassard; F. Richard; Ch. de la Taille; R. Pöschl; L. Raux; J. Rouëné; N. Seguin-Moreau; M. Anduze; V. Balagura; E. Becheva; V. Boudry; J-C. Brient; R. Cornat; M. Frotin; F. Gastaldi; F. Magniette; A. Matthieu; P. Mora de Freitas; H. Videau; J-E. Augustin; J. David; P. Ghislain; D. Lacour; L. Lavergne; J. Zacek; J. Cvach; P. Gallus; M. Havranek; M. Janata; J. Kvasnicka; D. Lednicky; M. Marcisovsky; I. Polak; J. Popule; L. Tomasek; M. Tomasek; P. Ruzicka; P. Sicho; J. Smolik; V. Vrba; J. Zalesak; D. Jeans; M. Götze

    2014-11-26T23:59:59.000Z

    A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 600,000 selected negatively changed pion events at energies between 2 and 10 GeV have been studied. The predictions of several physics models available within the GEANT4 simulation tool kit are compared to this data. Although a reasonable overall description of the data is observed, there are significant quantitative discrepancies in the longitudinal and transverse distributions of reconstructed energy.

  16. Performance of a Tungsten-Cerium Fluoride Sampling Calorimeter in High-Energy Electron Beam Tests

    E-Print Network [OSTI]

    Becker, R; Dissertori, G; Djambazov, L; Donegà, M; Lustermann, W; Marini, A C; Nessi-Tedaldi, F; Pandolfi, F; Peruzzi, M; Schönenberger, M; Cavallari, F; Dafinei, I; Diemoz, M; Lope, C Jorda; Meridiani, P; Nuccetelli, M; Paramatti, R; Pellegrino, F; Micheli, F; Organtini, G; Rahatlou, S; Soffi, L; Brianza, L; Govoni, P; Martelli, A; de Fatis, T Tabarelli; Monti, V; Pastrone, N; Trapani, P P; Candelise, V; Della Ricca, G

    2015-01-01T23:59:59.000Z

    A prototype for a sampling calorimeter made out of cerium fluoride crystals interleaved with tungsten plates, and read out by wavelength-shifting fibres, has been exposed to beams of electrons with energies between 20 and 150 GeV, produced by the CERN Super Proton Synchrotron accelerator complex. The performance of the prototype is presented and compared to that of a Geant4 simulation of the apparatus. Particular emphasis is given to the response uniformity across the channel front face, and to the prototype's energy resolution.

  17. A dimensionless parameter model for arc welding processes

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    1994-12-31T23:59:59.000Z

    A dimensionless parameter model previously developed for C0{sub 2} laser beam welding has been shown to be applicable to GTAW and PAW autogenous arc welding processes. The model facilitates estimates of weld size, power, and speed based on knowledge of the material`s thermal properties. The dimensionless parameters can also be used to estimate the melting efficiency, which eases development of weld schedules with lower heat input to the weldment. The mathematical relationship between the dimensionless parameters in the model has been shown to be dependent on the heat flow geometry in the weldment.

  18. Advanced RenewableEnergy Company ARC Energy | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat 1AMEE Jump to:Ohio:Ads-tec GmbHRenewableEnergy Company ARC

  19. Arc Vault Significantly Reduces Electrical Hazards | GE Global Research

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternativeOperational Management » History »Dept ofY-12ArahArc Vault

  20. ARCS - Access Rate Control System - Energy Innovation Portal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del(ANL-IN-03-032)8Li (59AJ76) (See theDoctoral20ALSNewstt^APPLIANCE STANDARDS HowARCS