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1/m<sub>c</sub> Terms in lambda<sup>+</sup><sub>c</sub> Semileptonic Decays (open access)

1/m<sub>c</sub> Terms in lambda<sup>+</sup><sub>c</sub> Semileptonic Decays

We use the heavy quark effective theory to investigate the form factors that describe the semileptonic decays lambda<sup>+</sup><sub>c</sub> -> lambda e<sup>+</sup> nu, to order 1/m<sub>c</sub>. We find that a total of four form factors are needed to this order, in contrast with two form factors to leading order, and six form factors in the most general case. We point out some relationships that arise among the general form factors.
Date: February 1, 1992
Creator: Roberts, Winston
System: The UNT Digital Library
The 17 keV neutrino and neutrino tagging (open access)

The 17 keV neutrino and neutrino tagging

P-788 at FNAL proposed to search for neutrino oscillations in a tagged neutrino line. A K{sub L} beam and the decay modes K{sub L} {yields} {pi}{mu}{nu}{sub {mu}} and K {sub L} {yields} {pi}e{nu}{sub e} provides the neutrino flux. An upstream tagging spectrometer then identifies the hadron and lepton and reconstructs the K{sub L} decay; the lepton identification will specifies the neutrino as {nu}{sub e} or {nu}{sub {mu}} and distinguishes {nu} from {bar {nu}} at the decay vertex. A neutrino detector modeled after an existing deep-inelastic scattering spectrometer (rates have been worked out for the CCFR apparatus) can be used to associate the K{sub L} with a neutrino interaction, measure the neutrino energy, and analyze outgoing muons. Monte Carlo studies show that 30K {nu}{sub e} and 20K {nu}{sub {mu}} could be obtained in two fixed target runs at the Tevatron.
Date: February 1, 1992
Creator: Bernstein, R.H.
System: The UNT Digital Library
The 17 keV neutrino and neutrino tagging (open access)

The 17 keV neutrino and neutrino tagging

P-788 at FNAL proposed to search for neutrino oscillations in a tagged neutrino line. A K{sub L} beam and the decay modes K{sub L} {yields} {pi}{mu}{nu}{sub {mu}} and K {sub L} {yields} {pi}e{nu}{sub e} provides the neutrino flux. An upstream tagging spectrometer then identifies the hadron and lepton and reconstructs the K{sub L} decay; the lepton identification will specifies the neutrino as {nu}{sub e} or {nu}{sub {mu}} and distinguishes {nu} from {bar {nu}} at the decay vertex. A neutrino detector modeled after an existing deep-inelastic scattering spectrometer (rates have been worked out for the CCFR apparatus) can be used to associate the K{sub L} with a neutrino interaction, measure the neutrino energy, and analyze outgoing muons. Monte Carlo studies show that 30K {nu}{sub e} and 20K {nu}{sub {mu}} could be obtained in two fixed target runs at the Tevatron.
Date: February 1, 1992
Creator: Bernstein, R. H.
System: The UNT Digital Library
The 1991 Natural Gas Vehicle Challenge: Developing Dedicated Natural Gas Vehicle Technology (open access)

The 1991 Natural Gas Vehicle Challenge: Developing Dedicated Natural Gas Vehicle Technology

An engineering research and design competition to develop and demonstrate dedicated natural gas-powered light-duty trucks, the Natural Gas Vehicle (NGV) Challenge, was held June 6--11, 1191, in Oklahoma. Sponsored by the US Department of Energy (DOE), Energy, Mines, and Resources -- Canada (EMR), the Society of Automative Engineers (SAE), and General Motors Corporation (GM), the competition consisted of rigorous vehicle testing of exhaust emissions, fuel economy, performance parameters, and vehicle design. Using Sierra 2500 pickup trucks donated by GM, 24 teams of college and university engineers from the US and Canada participated in the event. A gasoline-powered control testing as a reference vehicle. This paper discusses the results of the event, summarizes the technologies employed, and makes observations on the state of natural gas vehicle technology.
Date: February 1, 1992
Creator: Larsen, R.; Rimkus, W.; Davies, J.; Zammit, M. & Patterson, P.
System: The UNT Digital Library
Accelerator technology for bright radiation beam (open access)

Accelerator technology for bright radiation beam

We review the current and future accelerator technologies for generation of high brightness radiation beam.
Date: February 1, 1992
Creator: Kim, Kwang-Je
System: The UNT Digital Library
Accelerator technology for bright radiation beam (open access)

Accelerator technology for bright radiation beam

We review the current and future accelerator technologies for generation of high brightness radiation beam.
Date: February 1, 1992
Creator: Kim, Kwang-Je.
System: The UNT Digital Library
Advanced hybrid nuclear propulsion Mars mission performance enhancement (open access)

Advanced hybrid nuclear propulsion Mars mission performance enhancement

Nuclear electric propulsion (NEP), compared with chemical and nuclear thermal propulsion (NTP), can effectively deliver the same mass to Mars using much less propellant, consequently requiring less mass delivered to Earth orbit. The lower thrust of NEP requires a spiral trajectory near planetary bodies, which significantly increases the travel time. Although the total travel time is long, the portion of the flight time spent during interplanetary transfer is shorter, because the vehicle is thrusting for much longer periods of time. This has led to the supposition that NEP, although very attractive for cargo missions, is not suitable for piloted missions to Mars. However, with the application of a hybrid approach to propulsion, the benefits of NEP can be utilized while drastically reducing the overall travel time required. Development of a dual-mode system, which utilizes high-thrust NTP to propel the spacecraft from the planetary gravitational influence and low-thrust NEP to accelerate in interplanetary space, eliminates the spiral trajectory and results in a much faster transit time than could be obtained by either NEP or NTP alone. This results in a mission profile with a lower initial mass in low Earth orbit. In addition, the propulsion system would have the capability to …
Date: February 1, 1992
Creator: Dagle, J. E.; Noffsinger, K. E. & Segna, D. R.
System: The UNT Digital Library
Advanced hybrid nuclear propulsion Mars mission performance enhancement (open access)

Advanced hybrid nuclear propulsion Mars mission performance enhancement

Nuclear electric propulsion (NEP), compared with chemical and nuclear thermal propulsion (NTP), can effectively deliver the same mass to Mars using much less propellant, consequently requiring less mass delivered to Earth orbit. The lower thrust of NEP requires a spiral trajectory near planetary bodies, which significantly increases the travel time. Although the total travel time is long, the portion of the flight time spent during interplanetary transfer is shorter, because the vehicle is thrusting for much longer periods of time. This has led to the supposition that NEP, although very attractive for cargo missions, is not suitable for piloted missions to Mars. However, with the application of a hybrid approach to propulsion, the benefits of NEP can be utilized while drastically reducing the overall travel time required. Development of a dual-mode system, which utilizes high-thrust NTP to propel the spacecraft from the planetary gravitational influence and low-thrust NEP to accelerate in interplanetary space, eliminates the spiral trajectory and results in a much faster transit time than could be obtained by either NEP or NTP alone. This results in a mission profile with a lower initial mass in low Earth orbit. In addition, the propulsion system would have the capability to …
Date: February 1, 1992
Creator: Dagle, J. E.; Noffsinger, K. E. & Segna, D. R.
System: The UNT Digital Library
Alternative Cask Maintenance Facility concepts, an update and reassessment (open access)

Alternative Cask Maintenance Facility concepts, an update and reassessment

The results of three trade-off studies of alternative concepts for performing cask maintenance for Civilian Radioactive Waste Management System casks are presented. An earlier study resulted in a recommendation that a submerged pool concept for cask internal component removal be used in the design of a Cask Maintenance Facility. The first trade-off study resulted in confirming the previous recommendation that a submerged pool concept be used rather than an isolation cell; the basis for this continued recommendation is discussed. The second study provides an evaluation of the previously proposed facility for the capability of handling an increased quantity of OCRWM casks. This third study provides a preliminary concept for adding the capability to repaint the exterior cylindrical portions of casks.
Date: February 1, 1992
Creator: Attaway, C. R.; Medley, L. B.; Williamson, A.; Pope, R. B. & Shappert, L. B.
System: The UNT Digital Library
The American College of nuclear physicians 18th annual meeting and scientific sessions DOE day: Substance abuse and nuclear medicine abstracts (open access)

The American College of nuclear physicians 18th annual meeting and scientific sessions DOE day: Substance abuse and nuclear medicine abstracts

Despite the enormous personal and social cost Of substance abuse, there is very little knowledge with respect to the mechanisms by which these drugs produce addiction as well as to the mechanisms of toxicity. Similarly, there is a lack of effective therapeutic intervention to treat the drug abusers. In this respect, nuclear medicine could contribute significantly by helping to gather information using brain imaging techniques about mechanisms of drug addiction which, in turn, could help design better therapeutic interventions, and by helping in the evaluation and diagnosis of organ toxicity from the use of drugs of abuse. This volume contains six short descriptions of presentations made at the 18th Meeting of the American College of Nuclear Physicians -- DOE Day: Substance Abuse and Nuclear Medicine.
Date: February 1, 1992
Creator: unknown
System: The UNT Digital Library
Applications of circularly polarized photons at the ALS with a bend magnet source (open access)

Applications of circularly polarized photons at the ALS with a bend magnet source

The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High {Tc} Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studies of Highly Correlated Systems; and Instrumentation for Photon Transport and Polarization Measurements.
Date: February 1, 1992
Creator: unknown
System: The UNT Digital Library
Applications of circularly polarized photons at the ALS with a bend magnet source (open access)

Applications of circularly polarized photons at the ALS with a bend magnet source

The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High {Tc} Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studies of Highly Correlated Systems; and Instrumentation for Photon Transport and Polarization Measurements.
Date: February 1, 1992
Creator: unknown
System: The UNT Digital Library
An approximation method for dynamic response of strain-hardening structures (open access)

An approximation method for dynamic response of strain-hardening structures

An approximation method is being developed to predict the dynamic plastic response of rigid, strain-hardening structures. This method is analogous to the instantaneous mode techniques used to treat rigid, perfectly plastic structures in that deflection shape involving a number of arbitrary functions of time selected, based on static deformation profiles. Two stress fields are associated with the deflection shape: one satisfies the equations of motion with appropriate boundary and continuity conditions, and the other satisfies the strain-hardening constitutive relation with appropriate boundary and smoothness conditions. The method is illustrated using the case of a simply-supported beam with a central plastic region.
Date: February 1, 1992
Creator: Youngdahl, C.K.
System: The UNT Digital Library
An approximation method for dynamic response of strain-hardening structures (open access)

An approximation method for dynamic response of strain-hardening structures

An approximation method is being developed to predict the dynamic plastic response of rigid, strain-hardening structures. This method is analogous to the instantaneous mode techniques used to treat rigid, perfectly plastic structures in that deflection shape involving a number of arbitrary functions of time selected, based on static deformation profiles. Two stress fields are associated with the deflection shape: one satisfies the equations of motion with appropriate boundary and continuity conditions, and the other satisfies the strain-hardening constitutive relation with appropriate boundary and smoothness conditions. The method is illustrated using the case of a simply-supported beam with a central plastic region.
Date: February 1, 1992
Creator: Youngdahl, C. K.
System: The UNT Digital Library
Architecture flow diagrams under teamwork reg sign (open access)

Architecture flow diagrams under teamwork reg sign

The Teamwork CASE tool allows Data Flow Diagrams (DFDs) to be maintained for structured analysis. Fermilab has extended teamwork under UNIX{trademark} to permit Hatley and Pirbhai Architecture Flow Diagrams (AFDs) to be associated with DFDs and subsequently maintained. This extension, called TWKAFD, allows a user to open an AFD, graphically edit it, and replace it into a TWKAFD maintained library. Other aspects of Hatley and Pirbhai's methodology are supported. This paper presents a quick tutorial on Architecture Diagrams. It then describes the user's view of TWKAFD, the experience incorporating it into teamwork, and the successes with using the Architecture Diagram methodology along with the shortcomings of using the teamwork/TWKAFD tool. 8 refs.
Date: February 1, 1992
Creator: Nicinski, T.
System: The UNT Digital Library
Architecture flow diagrams under teamwork{reg_sign} (open access)

Architecture flow diagrams under teamwork{reg_sign}

The Teamwork CASE tool allows Data Flow Diagrams (DFDs) to be maintained for structured analysis. Fermilab has extended teamwork under UNIX{trademark} to permit Hatley and Pirbhai Architecture Flow Diagrams (AFDs) to be associated with DFDs and subsequently maintained. This extension, called TWKAFD, allows a user to open an AFD, graphically edit it, and replace it into a TWKAFD maintained library. Other aspects of Hatley and Pirbhai`s methodology are supported. This paper presents a quick tutorial on Architecture Diagrams. It then describes the user`s view of TWKAFD, the experience incorporating it into teamwork, and the successes with using the Architecture Diagram methodology along with the shortcomings of using the teamwork/TWKAFD tool. 8 refs.
Date: February 1, 1992
Creator: Nicinski, T.
System: The UNT Digital Library
The audit checklist: Your key to audit success (open access)

The audit checklist: Your key to audit success

As the old saying goes, If you have no objective, any road will take your there.'' So it is with the audit checklist. The checklist is the primary tool for providing order to Quality Assurance audit activities. With a well-planned and well-defined checklist, success is achievable. Without a checklist, the auditor has a disjointed, disorganized activity and no place to document his or her failed efforts. A number of formal quality programs which include audits as one of their program elements require the audit to be performed using a checklist or procedures to document what the auditor reviewed and what he or she found. It is the intent of this paper to provide the reader with the some insight as to the value of the checklist; the varieties of checklists that can be constructed; the pitfalls of improper application; and the success that can be achieved when the checklist has been properly researched, developed, and deployed.
Date: February 1, 1992
Creator: Maday, J.H. Jr.
System: The UNT Digital Library
The audit checklist: Your key to audit success (open access)

The audit checklist: Your key to audit success

As the old saying goes, ``If you have no objective, any road will take your there.`` So it is with the audit checklist. The checklist is the primary tool for providing order to Quality Assurance audit activities. With a well-planned and well-defined checklist, success is achievable. Without a checklist, the auditor has a disjointed, disorganized activity and no place to document his or her failed efforts. A number of formal quality programs which include audits as one of their program elements require the audit to be performed using a checklist or procedures to document what the auditor reviewed and what he or she found. It is the intent of this paper to provide the reader with the some insight as to the value of the checklist; the varieties of checklists that can be constructed; the pitfalls of improper application; and the success that can be achieved when the checklist has been properly researched, developed, and deployed.
Date: February 1, 1992
Creator: Maday, J. H. Jr.
System: The UNT Digital Library
Beamstrahlung spectra in next generation linear colliders (open access)

Beamstrahlung spectra in next generation linear colliders

For the next generation of linear colliders, the energy loss due to beamstrahlung during the collision of the e{sup +}e{sup {minus}} beams is expected to substantially influence the effective center-of-mass energy distributions of the colliding particles. In this paper, we first derive analytical formulae for the electron and photon energy spectra under multiple beamstrahlung processes, and for the e{sup +}e{sup {minus}} and {gamma}{gamma} differential luminosities. We then apply our formalism to various classes of 500 GeV e{sup +}e{sup {minus}} linear collider designs currently under study.
Date: February 1, 1992
Creator: Barklow, T.; Chen, P. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)) & Kozanecki, W. (CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France))
System: The UNT Digital Library
Beamstrahlung spectra in next generation linear colliders (open access)

Beamstrahlung spectra in next generation linear colliders

For the next generation of linear colliders, the energy loss due to beamstrahlung during the collision of the e{sup +}e{sup {minus}} beams is expected to substantially influence the effective center-of-mass energy distributions of the colliding particles. In this paper, we first derive analytical formulae for the electron and photon energy spectra under multiple beamstrahlung processes, and for the e{sup +}e{sup {minus}} and {gamma}{gamma} differential luminosities. We then apply our formalism to various classes of 500 GeV e{sup +}e{sup {minus}} linear collider designs currently under study.
Date: February 1, 1992
Creator: Barklow, T.; Chen, P. & Kozanecki, W.
System: The UNT Digital Library
Calculation of Savannah River K Reactor Mark-22 assembly LOCA/ECS power limits (open access)

Calculation of Savannah River K Reactor Mark-22 assembly LOCA/ECS power limits

This paper summarizes the results of TRAC-PF1/MOD3 calculations of Mark-22 fuel assembly of loss-of-coolant accident/emergency cooling system (LOCA/ECS) power limits for the Savannah River Site (SRS) K Reactor. This effort was part of a larger effort undertaken by the Los Alamos National Laboratory for the US Department of Energy to perform confirmatory power limits calculations for the SRS K Reactor. A method using a detailed three-dimensional (3D) TRAC model of the Mark-22 fuel assembly was developed to compute LOCA/ECS power limits. Assembly power was limited to ensure that no point on the fuel assembly walls would exceed the local saturation temperature. The detailed TRAC model for the Mark-22 assembly consisted of three concentric 3D vessel components which simulated the two targets, two fuel tubes, and three main flow channels of the fuel assembly. The model included 100% eccentricity between the assembly annuli and a 20% power tilt. Eccentricity in the radial alignment of the assembly annuli arises because axial spacer ribs that run the length of the fuel and targets are used. Wall-shear, interfacial-shear, and wall heat-transfer correlations were developed and implemented in TRAC-PF1/MOD3 specifically for modeling flow and heat transfer in the narrow ribbed annuli encountered in the Mark-22 …
Date: February 1, 1992
Creator: Fischer, S. R.; Farman, R. F. & Birdsell, S. A.
System: The UNT Digital Library
Calculational benchmark comparisons for a low sodium void worth actinide burner core design (open access)

Calculational benchmark comparisons for a low sodium void worth actinide burner core design

Recently, a number of low void worth core designs with non-conventional core geometries have been proposed. Since these designs lack a good experimental and computational database, benchmark calculations are useful for the identification of possible biases in performance characteristics predictions. In this paper, a simplified benchmark model of a metal fueled, low void worth actinide burner design is detailed; and two independent neutronic performance evaluations are compared. Calculated performance characteristics are evaluated for three spatially uniform compositions (fresh uranium/plutonium, batch-averaged uranium/transuranic, and batch-averaged uranium/transuranic with fission products) and a regional depleted distribution obtained from a benchmark depletion calculation. For each core composition, the flooded and voided multiplication factor, power peaking factor, sodium void worth (and its components), flooded Doppler coefficient and control rod worth predictions are compared. In addition, the burnup swing, average discharge burnup, peak linear power, and fresh fuel enrichment are calculated for the depletion case. In general, remarkably good agreement is observed between the evaluations. The most significant difference is predicted performance characteristics is a 0.3--0.5% {Delta}k/(kk) bias in the sodium void worth. Significant differences in the transmutation rate of higher actinides are also observed; however, these differences do not cause discrepancies in the performing predictions.
Date: February 1, 1992
Creator: Hill, R. N.; Kawashima, M.; Arie, K. & Suzuki, M.
System: The UNT Digital Library
Catalysis at experimentally designed surfaces: n-Butane hydrogenolysis at Sn/Group VIII surface alloys (open access)

Catalysis at experimentally designed surfaces: n-Butane hydrogenolysis at Sn/Group VIII surface alloys

Bimetallic {radical}3x{radical}3R30{degrees}-Sn/M(111) [M=Ni, Pt] surface alloys have been prepared in an ultrahigh vacuum system and used in model moderate pressure (1--200 Torr) catalytic reactions. Hydrogenolysis of n-butane (H{sub 2}/n-C4=20) has been used to characterize the effects of ordered bimetallic ensembles relative to those available at the respective (111) surfaces. The effect of alloying Sn into the Ni(111) surface produced an overall lowering of the catalytic reactivity nearly equal to the number of Ni surface sites lost upon producing the {radical}3x{radical}3R30{degrees} surface alloy. In addition, the overall rate of hydrogenolysis of n-butane at the {radical}3x{radical}R30{degrees}-Sn/Pt(111) surface alloy was also found to have decreased (although not in proportion to the loss of total Pt atoms). Catalytic deactivation due to carbon buildup was observed to decrease significantly at both of the ordered {radical}3x{radical}3R30{degrees}-Sn/M(111) surface alloys under reaction conditions.
Date: February 1, 1992
Creator: Logan, A. D. & Paffett, M. T.
System: The UNT Digital Library
Ceramic microstructures and their elucidation by imaging, diffraction and spectroscopic methods (open access)

Ceramic microstructures and their elucidation by imaging, diffraction and spectroscopic methods

The development and potential utilization of ceramic materials is dependent on a systematic effort involving processing, characterization and appropriate property measurements. The methods of characterization are numerous and it is important to employ the one that is appropriate to the problem both in terms of its information content and the achievable level of resolution. With the incorporation of fine probe forming capabilities in a transmission electron microscope and the development of related diffraction, imaging and spectroscopic methods, it is now possible to obtain structural and chemical information from the same region of the sample at high spatial resolution. In this review, recent advances along with representative examples in the application of high resolution electron microscopy (HREM), convergent beam electron diffraction (CBED), low atomic number element microanalysis by x-ray emission spectroscopy (XES), fine structures in electron energy-loss spectroscopy (EELS) and specific site occupancy determination by channeling experiments are discussed.
Date: February 1, 1992
Creator: Kirshnan, K.M.
System: The UNT Digital Library