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Oak Ridge rf Test Facility
The rf Test Facility (RFTF) of Oak Ridge National Laboratory (ORNL) provides a national facility for the testing and evaluation of steady-state, high-power (approx.1.0-MW) ion cyclotron resonance heating (ICRH) systems and components. The facility consists of a vacuum vessel and two fully tested superconducting development magnets from the ELMO Bumpy Torus Proof-of-Principle (EBT-P) program. These are arranged as a simple mirror with a mirror ratio of 4.8. The axial centerline distance between magnet throat centers is 112 cm. The vacuum vessel cavity has a large port (74 by 163 cm) and a test volume adequate for testing prototypic launchers for Doublet III-D (DIII-D), Tore Supra, and the Tokamak Fusion Test Reactor (TFTR). Attached to the internal vessel walls are water-cooled panels for removing the injected rf power. The magnets are capable of generating a steady-state field of approx.3 T on axis in the magnet throats. Steady-state plasmas are generated in the facility by cyclotron resonance breakdown using a dedicated 200-kW, 28-GHz gyrotron. Available rf sources cover a frequency range of 2 to 200 MHz at 1.5 kW and 3 to 18 MHz at 200 kW, with several sources at intermediate parameters. Available in July 1986 will be a >1.0-MW, cw …
Date:
January 1, 1985
Creator:
Gardner, W.L.; Hoffman, D.J.; McCurdy, H.C.; McManamy, T.J.; Moeller, J.A. & Ryan, P.M.
System:
The UNT Digital Library
Thin film porous membranes based on sol-gel chemistry for catalytic sensors
Nanoporous sol-gel based films are finding a wide variety of uses including gas separations and supports for heterogeneous catalysts. The films can be formed by spin or dip coating, followed by relatively low temperature annealing. The authors used several types of these films as coatings on the Pd alloy thin film sensors they had previously fabricated and studied. The sol-gel films have little effect on the sensing response to H{sub 2} alone. However, in the presence of other gases, the nanoporous film modifies the sensor behavior in several beneficial ways. (1) They have shown that the sol-gel coated sensors were only slightly poisoned by high concentrations of H{sub 2}S while uncoated sensors showed moderate to severe poisoning effects. (2) For a given partial pressure of H{sub 2}, the signal from the sensor is modified by the presence of O{sub 2} and other oxidizing gases.
Date:
May 1, 1998
Creator:
Hughes, R. C.; Patel, S. V.; Jenkins, M. W.; Boyle, T. J.; Gardner, T. J. & Brinker, C. J.
System:
The UNT Digital Library
ICRF heating on TFTR with the ORNL antenna
Initial ion cyclotron range of frequencies (ICRF) heating experiments on TFTR began in the summer of 1988. Although we were in the commissioning stage for much of the equipment, some plasma coupling measurements were made in the fall. This paper is focused on the results from the Bay L antenna. 3 refs., 3 figs., 1 tab.
Date:
January 1, 1989
Creator:
Hoffman, D. J.; Gardner, W. L.; Ryan, P. M.; Greene, G. J.; Hosea, J. C.; Wilson, J. R. et al.
System:
The UNT Digital Library
Detection of adventitious viruses from biologicals using a broad spectrum Microbial Detection Array
None
Date:
May 24, 2011
Creator:
Jaing, C; Gardner, S; McLoughlin, K; Thissen, J & Slezak, T
System:
The UNT Digital Library
ACCELERATING CLOSURE AT DOE SITES WITH EM'S SCIENCE AND TECHNOLOGY PROGRAM
Technical support is important for all U.S. Department of Energy (DOE) facilities facing difficult technical issues, aggressive remediation schedules, and tight budgets. It is especially vital for closure sites, which typically are smaller and have fewer resources available to apply to remediation activities. In many cases, closure sites and other small sites no longer have staff with the expertise required to overcome technical barriers on their own. As closure deadlines approach, special technical expertise is needed to identify, evaluate, and implement new and innovative approaches that will result in significant cost and schedule improvement for the waste disposition pathway. Site ''problem holders'' must have access to world-class scientific and engineering expertise from DOE national laboratories and research facilities, private industry, and universities to address immediate critical problems. In order to have confidence in the feasibility and results of innovative approaches, site contractors need to have the benefit of the valuable experiences of technicians who have faced similar problems and found solutions. The DOE Environmental Management (EM) Science and Technology (S&T) program recognizes the need of the closure sites to solve problems aggressively and is highly responsive to this need. Technical support from the S&T program can take many forms, such …
Date:
February 27, 2003
Creator:
Walker, J. S.; Toussaint, Craig R., (info: Ph.D.) & Gardner, E. J.
System:
The UNT Digital Library
Ion-implantation doping of silicon carbide
Because of their commercial availability in bulk single crystal form, the 6H- and 4H- polytypes of SiC are gaining importance for high-power, high-temperature, and high-frequency device applications. Selective area doping is a crucial processing step in integrated circuit manufacturing. In Si technology, selective area doping is accomplished by thermal diffusion or ion-implantation. Because of the low diffusion coefficients of most impurities in SiC, ion implantation is indispensable in SiC device manufacturing. In this paper the authors present their results on donor, acceptor, and compensation implants in 6H-SiC.
Date:
October 1, 1997
Creator:
Gardner, J.; Edwards, A.; Rao, M.V.; Papanicolaou, N.; Kelner, G. & Holland, O.W.
System:
The UNT Digital Library
Performance of coils wound from long lengths of surface-coated, reacted, BSCCO-2212 conductor
React-before-wind surface-coated BSCCO-2212 is being established as a relatively low cost HTS conductor for practical applications. Quality tape is presently being manufactured in 450-500m lengths at a cost estimated to be 1/3-1/5 of the industry costs of BSCCO-2223 powder-in-tube tape. Robust, mechanically sound coils for applications ranging from NMR insert magnets to transformer windings are being made from this BSCCO-2212 tape. The coils have performed consistently through test and thermal cycling without degradation and as projected from short sample measurements. A hybrid approach, which uses mainly BSCCO- 2212 augmented by BSCCO-2223 conductor in the high radial field end regions, is expected to halve magnet system costs.
Date:
October 1996
Creator:
Walker, M. S.; Hazelton, D. W. & Gardner, M. T.
System:
The UNT Digital Library
Neutron capture cross sections for unstable nuclei in the mass 90 region derived from proton capture measurements. [Strength functions]
Experimental measurements were made of the production cross sections and energy distributions of gamma rays emitted when the stable targets /sup 88/Sr, /sup 89/Y and /sup 90/Zr are exposed to protons in the energy range 3 to 8 MeV. The data are being analyzed using a recent version of the Uhl statistical model code. One conclusion is that while the gamma-ray strength functions employed reproduce the proton capture cross sections, they do not achieve the same degree of hardness observed in the measured spectra. To do so, their lower energy regions must be modified; such changes, however, do not affect the capture cross sections. 7 references.
Date:
September 1, 1978
Creator:
Gardner, D. G.; Dietrich, F. S. & Heikkinen, D. W.
System:
The UNT Digital Library
Results of the fourth Hanna field test
The second phase (Hanna IVB) of a coal gasification experiment near Hanna, Wyoming, was completed in September 1979. The experiment attempted to link and gasify coal between process wells spaced 34.3 meters apart. Intermediate wells were positioned between the process wells so that the link could be relayed over shorter distances. Reverse combustion linking was attempted over a 22.9-meter and a 11.4-meter distance of the total well spacing. Thermal activity was generally noted in the upper 3 meters of the coal seam during the link. Two attempts to gasify over the 34.3-meter distance resulted in the propagation of the burn front at the coal overburden interface. Post-burn evaluation indicates fractures as major influencing factors of the combustion process. The Hanna IVB field test provided much insight into influence that geologic features have on in situ coal combustion. The influence of these faults, permeable zones, and cleats, on the air flow patterns can drastically change the overall results of a gasification experiment and should be studied further. The overall results of Hanna IVB were discouraging because of the rapid decline in the heating values for the production gas and the amount of coal gasified. With more complete geologic characerization prior to …
Date:
January 1, 1980
Creator:
Covell, J. R.; Wojdac, L. F.; Barbour, F. A.; Gardner, G. W.; Glass, R. & Hommert, P. J.
System:
The UNT Digital Library
The Rapid Cycling Medical Synchrotron RCMS.
Thirteen hadron beam therapy facilities began operation between 1990 and 2001 - 5 in Europe, 4 in North America, 3 in Japan, and 1 in South Africa [l]. Ten of them irradiate tumors with protons, 2 with Carbon- 12 ions, and 1 with both protons and Carbon-12. The facility with the highest patient throughput - a total of 6 174 patients in 11 years and as many as 150 patient treatments per day -is the Loma Linda University Medical Center, which uses a weak focusing slow cycling synchrotron to accelerate beam for delivery to passive scattering nozzles at the end of rotatable gantries [2, 3,4]. The Rapid Cycling Medical Synchrotron (RCMS) is a second generation synchrotron that, by contrast with the Loma Linda synchrotron, is strong focusing and rapid cycling, with a repetition rate of 30 Hz. Primary parameters for the RCMS are listed in Table 1.
Date:
June 2, 2002
Creator:
Peggs, S.; Barton, D.; Beebe-Wang, J.; Cardona, J.; Brennan, M.; Fischer, W. et al.
System:
The UNT Digital Library
Accumulator ring lattice for the national spallation neutron source
The Accumulator Ring for the proposed National Spallation Neutron Source (NSNS) is to accept a 1.03 millisecond beam pulse from a 1 GeV Proton Linac at a repetition rate of 60 Hz. For each beam pulse, 10{sup 14} protons are to be accumulated via charge-exchange injection. A 295 nanosecond gap in the beam, maintained by an rf system, will allow for extraction to an external target for the production of neutrons by spallation. This paper describes the four-fold symmetric lattice that has been chosen for the ring. The lattice contains four long dispersion-free straight sections to accomodate injection, extraction, rf cavities, and beam scraping respectively. The four-fold symmetry allows for easy adjustment of the tunes and flexibility in the placement of correction elements, and ensures that potentially dangerous betatron structure resonances are avoided.
Date:
August 1997
Creator:
Gardner, C. J.; Lee, Y. Y. & Luccio, A. U.
System:
The UNT Digital Library
FODO/Doublet Lattice for the SNS Accumulator Ring.
Requirements of minimum beam loss for hand-on maintenance and flexibility for future operations are essential for the lattice design of the Spallation Neutron Source (SNS) accumulator ring. In this paper, we present a hybrid lattice that consists of FODO arcs and doublet straights, emphasizing injection and collimation optimization and flexibility, split tunes for coupling control, sextupole families for chromaticity control, and compatibility to future upgrades.
Date:
June 30, 2000
Creator:
Wei, J.; Gardner, C.; Lee, Y. Y. & Tsoupas, N.
System:
The UNT Digital Library
Support chemistry, surface area, and preparation effects on sulfided NiMo catalyst activity
Hydrous Metal Oxides (HMOs) are chemically synthesized materials which contain a homogeneous distribution of ion exchangeable alkali cations that provide charge compensation to the metal-oxygen framework. In terms of the major types of inorganic ion exchangers defined by Clearfield, these amorphous HMO materials are similar to both hydrous oxides and layered oxide ion exchangers (e.g., alkali metal titanates). For catalyst applications, the HMO material serves as an ion exchangeable support which facilitates the uniform incorporation of catalyst precursor species. Following catalyst precursor incorporation, an activation step is required to convert the catalyst precursor to the desired active phase. Considerable process development activities at Sandia National Laboratories related to HMO materials have resulted in bulk hydrous titanium oxide (HTO)- and silica-doped hydrous titanium oxide (HTO:Si)-supported NiMo catalysts that are more active in model reactions which simulate direct coal liquefaction (e.g., pyrene hydrogenation) than commercial {gamma}-Al{sub 2}O{sub 3}-supported NiMo catalysts. However, a fundamental explanation does not exist for the enhanced activity of these novel catalyst materials; possible reasons include fundamental differences in support chemistry relative to commercial oxides, high surface area, or catalyst preparation effects (ion exchange vs. incipient wetness impregnation techniques). The goals of this paper are to identify the key …
Date:
June 1, 1996
Creator:
Gardner, Timothy J.; McLaughlin, Linda I. & Sandoval, Ronald S.
System:
The UNT Digital Library
Predicting cancer outcome
We read with interest the paper by Michiels et al on the prediction of cancer with microarrays and the commentary by Ioannidis listing the potential as well as the limitations of this approach (February 5, p 488 and 454). Cancer is a disease characterized by complex, heterogeneous mechanisms and studies to define factors that can direct new drug discovery and use should be encouraged. However, this is easier said than done. Casti teaches that a better understanding does not necessarily extrapolate to better prediction, and that useful prediction is possible without complete understanding (1). To attempt both, explanation and prediction, in a single nonmathematical construct, is a tall order (Figure 1).
Date:
March 24, 2005
Creator:
Gardner, S N & Fernandes, M
System:
The UNT Digital Library
Intercomparison of theoretical calculations of important activation cross sections for fusion reactor technology
Various theoretical calculations of radionuclides in the reactions {sup 94}Mo(n,p){sup 94}Nb, {sup 109}Ag(n,2n){sup 108m}Ag, {sup 151}Eu(n,2n){sup 150m}Eu, {sup 153}Eu(n,2n){sup 152g+m2}Eu, {sup 159}Tb(n,2n){sup 158}Tb, {sup 187}Re(n,2n){sup 186m}Re, {sup 179}Hf(n,2n){sup l78m2}Hf, {sup 193}Ir(n,2n){sup 192m2}Ir are compared. We normalize the theoretical results to the evaluated experimental data at 14.5 MeV, and take their average. This yields averaged theoretical excitation functions for the production of the various radionuclides at neutron energies ranging from threshold to 14.5 MeV. We discuss differences between the various theoretical results, and between theory and data where they exist. Our theoretical results may be used in conjunction with experimental data to produce evaluated radionuclide production cross sections for neutron energies lower than 14.5 MeV.
Date:
November 1, 1993
Creator:
Chadwick, M. B.; Gardner, M.; Gardner, D.; Grudzevich, O. T.; Ignatyuk, A. V.; Meadows, J. W. et al.
System:
The UNT Digital Library
The Impact of Intrinsic Heavy Quark Distributions in the Proton on New Physics Searches at the High Intensity Frontier
The possibility of an intense proton facility, at 'Project X' or elsewhere, will provide many new opportunities for searches for physics beyond the Standard Model. A Project X can serve a yet broader role in the search for new physics, and in this note we highlight the manner in which thus-enabled studies of the flavor structure of the proton, particularly of its intrinsic heavy quark content, facilitate other direct and indirect searches for new physics. Intrinsic heavy quarks in both light and heavy hadrons play a key role in searches for physics BSM with hadrons - and their study at the Intensity Frontier may prove crucial to establishing its existence.
Date:
February 16, 2012
Creator:
Brodsky, Stanley & Gardner, Susan
System:
The UNT Digital Library
Harmonic analysis of the AGS Booster imperfection
The harmonic content of magnetic field imperfections in the AGS Booster has been determined through careful measurements of the required field corrections of transverse resonances. An analysis of the required correction yielded amplitude and phase information which points to possible sources of imperfections. Dipole and quadrupole imperfections, which are proportional to the field of bending magnets (B), are mainly driven by any misalignment of the magnets. Quadrupole and sextupole imperfections, which are proportional to dB/dt, are driven by imperfections of the eddy-current correction system. The observations also suggest the presence of a remnant field.
Date:
December 31, 1993
Creator:
Shoji, Y. & Gardner, C.
System:
The UNT Digital Library
Analysis of plasma coupling with the prototype DIII-D ICRF antenna
Coupling to plasma in the H-mode is essential to the success of future ignited machines such as CIT. To ascertain voltage and current requirements for high-power second harmonic heating (2 MW in a 35- by 50-cm port), coupling to the DIII-D tokamak with a prototype compact loop antenna has been measured. The results show good loading for L-mode and limiter plasmas, but coupling 2 MW to an H-mode plasma demands voltages and currents near the limit of present technology. We report the technological analysis and progress that allow coupling of these power densities. 5 refs., 4 figs.
Date:
January 1, 1988
Creator:
Ryan, P.M.; Hoffman, D.J.; Bigelow, T.S.; Baity, F.W.; Gardner, W.L.; Mayberry, M.J. et al.
System:
The UNT Digital Library
The operational status of the Booster injector for the AGS accelerator complex at BNL
The Booster synchrotron at Brookhaven National Laboratory has been incorporated into the accelerator chain at the Alternating Gradient Synchrotron (AGS) complex. After a successful first commissioning effort in the spring of 1991, the Booster has been part of this year`s silicon, gold and proton physics runs. After a brief review of the Booster design goals, and of the early commissioning, this paper will summarize this year`s activities.
Date:
September 1, 1992
Creator:
Ahrens, L.; Bleser, E.; Brennan, J. M.; Gardner, C.; Gill, E.; Glenn, J. W. et al.
System:
The UNT Digital Library
The operational status of the Booster injector for the AGS accelerator complex at BNL
The Booster synchrotron at Brookhaven National Laboratory has been incorporated into the accelerator chain at the Alternating Gradient Synchrotron (AGS) complex. After a successful first commissioning effort in the spring of 1991, the Booster has been part of this year's silicon, gold and proton physics runs. After a brief review of the Booster design goals, and of the early commissioning, this paper will summarize this year's activities.
Date:
January 1, 1992
Creator:
Ahrens, L.; Bleser, E.; Brennan, J. M.; Gardner, C.; Gill, E.; Glenn, J. W. et al.
System:
The UNT Digital Library
Setup and Performance of the Rhic Injector Accelerators for the 2007 Run With Gold Ions
Gold ions for the 2007 run of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of this chain of accelerators is reviewed with a focus on improvements in the quality of beam delivered to RHIC. In particular, more uniform stripping foils between Booster and AGS7 and a new bunch merging scheme in AGS have provided beam bunches with reduced longitudinal emittance for RHIC.
Date:
June 25, 2007
Creator:
Gardner, C.; Ahrens, L.; Alessi, J.; Benjamin, J.; Blaskiewicz, M. & Al., Et
System:
The UNT Digital Library
Lower active metals loading for hydrotreating catalysts
Hydrous Metal Oxides (HMOs) are chemically synthesized materials which contain a homogeneous distribution of ion exchangeable alkali cations that provide charge compensation to the metal-oxygen framework. Both the presence of these alkali cations and the resulting high cation exchange capacities (4-5 meq/g) clearly set these HMO materials apart from conventional precipitated hydrous oxides. For catalyst applications, the HMO material serves as an ion exchangeable support which facilitates the uniform incorporation of catalyst precursor species. Following catalyst precursor incorporation, an activation step is required to convert the catalyst precursor to the desired active phase. Considerable process development activities at Sandia National Laboratories related to HMO materials have resulted in bulk silica-doped hydrous titanium oxide (HTO:Si)-supported NiMo catalysts that are more active in model compound reactions than commercial NiMo catalysts. These reactions, e.g. pyrene hydrogenation, simulate direct coal liquefaction. However, extension of this process to produce NiMo/HTO:Si catalyst coatings on commercial supports is of interest for liquefaction applications since overall catalyst cost can be reduced and bulk HTO:Si mechanical limitations can be circumvented. In the present effort, NiMo/HTO:Si has been evaluated for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of coal derived liquids. NiMo/HTO:Si catalysts have been evaluated in both bulk (unsupported) form and …
Date:
September 1, 1994
Creator:
Lott, S. E.; Gardner, T. J.; McLaughlin, L. I. & Oelfke, J. B.
System:
The UNT Digital Library
Comparison of nickel molybdenum hydrous metal oxides with commercial catalysts for HDS/HDN of coal liquids
Improved efficiency in direct coal liquefaction processes can be obtained by developing catalysts with better activity, selectivity, and life. In previous exploratory research at Sandia National Laboratories, catalysts prepared via hydrous metal oxide (HMO) ion exchangers have been shown to have potential for application to a number of reactions associated with the conversion of coal to liquid fuels. In the present effort, one member of this class of catalysts, hydrous titanium oxide (HTO), has been used to develop catalysts for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of coal liquids. For HYD of pyrone, unsupported NiMoHTO catalysts performed better than commercial benchmark catalysts on either a catalyst weight or active metals basis. In a side-by-side comparison of supported NiMoHTO catalysts with commercial counterparts, the supported NiMoHTO catalysts outperformed the Shell 324 and Amocat 1C catalysts for HYD of pyrene. For HDS/HDN of coal liquids, the supported and bulk forms of the NiMoHTO catalysts equaled the performance of the commercial catalysts at 500, 1000, and 1500 psig while containing less active metals. Possible reasons for the high activity of the NiMoHTO catalysts are a high dispersion of the active MoS{sub 2} phase and a high acidity of the bulk NiMoHTO.
Date:
June 1, 1994
Creator:
Lott, S. E.; Gardner, T. J.; McLaughlin, L. I. & Oelfke, J. B.
System:
The UNT Digital Library
Hydrotreating studies involving NiMo/silica-doped hydrous titanium oxide (HTO:Si)-coated alumina catalysts
For hydrotreating a petroleum-derived liquid feed at 400 C, LHSV = 2. 5 g/g{sub cat}/h, and 1500 psig hydrogen (H) pressure, both HDS and HDN activities were roughly equivalent for a name/TO:Si-coated Amocat catalyst and a commercial alumina-supported name catalyst (Amocat 1C). Superior HDN performance was exhibited by the name/TO: Si-coated Amocat catalyst at low H pressure (500 psig) and after H pressure cycling (1500-500-1500 psig) relative to Amocat 1C. Consistent with previous results obtained on a coal-derived liquid feed, the HDS/HDN results with the petroleum-derived liquid showed that the performance of the name/TO:Si-coated Amocat catalyst on an active metals weight basis exceeded the performance of Amocat 1C at all test conditions. The name/TO:Si-coated Amocat catalyst also showed potentially increased hydrogenation activity, increased resistance to deactivation, and increased yields of lower boiling point distillate fractions, although further work is needed.
Date:
July 1, 1996
Creator:
Gardner, T.J.; Miller, J.E.; McLaughlin, L.I. & Trudell, D.E.
System:
The UNT Digital Library