Effect of Airflow and Heat Input Rates on Duct Efficiency. (open access)

Effect of Airflow and Heat Input Rates on Duct Efficiency.

Reducing the airflow and heat input rates of a furnace that is connected to a duct system in thermal contact with unconditioned spaces can significantly reduce thermal distribution efficiency. This is a straightforward theoretical calculation based on the increased residence time of the air in the duct at the lower flow rate, which results in greater conduction losses. Experimental tests in an instrumented residential-size duct system have confirmed this prediction. Results are compared with the heat-loss algorithm in ASHRAE Standid 152P. The paper concludes with a discussion of possible remedies for this loss of efficiency in existing systems and optional design strategies in new construction.
Date: May 28, 2003
Creator: Andrews, J. W.
Object Type: Report
System: The UNT Digital Library
Investigation and simulation of muon cooling rings with tilted solenoids (open access)

Investigation and simulation of muon cooling rings with tilted solenoids

Alternating solenoid focused muon cooling ring without special bending magnets is considered and investigate in detail. Both fringe field between solenoid coils with opposite directed current, and an inclination of the coils in vertical plane are used to provide a bending and closing of the particle trajectories. Realistic (Maxwellian) magnetic field is calculated and used for a simulation. Methodic is developed and applied to find closed orbit at any energy, dispersion, region of stability, and other conventional accelerator characteristics. Earlier proposed RFOFO cooling ring with 200 MHz RF system and liquid hydrogen absorbers is investigated in detail. After an optimization, normalized 6D emittance about 20 mm{sup 3} and transmission 57% are obtained.
Date: May 28, 2003
Creator: Balbekov, Valeri I.
Object Type: Article
System: The UNT Digital Library
Lithium lenses based muon cooling channel (open access)

Lithium lenses based muon cooling channel

A linear ionization cooling channel for neutrino factory or muon collider is considered. It includes short Li lenses, matching solenoids, and 201 MHz RF cavities. The basic challenge is a suppression of chromatic effects in a wide energy range typical for muon beams. A special lattice is proposed to reach this, and methodic of an optimization is developed to minimize the chromatic aberrations by suppression of several betatron resonances. The most engineering constraint is a high field of matching solenoids. A channel with less of 10 T field is considered in detail. It is capable to cool transverse emittance of a beam from 2-3 mm to 0.5 mm at the channel length of about 130 m. Because there is no emittance exchange, longitudinal emittance increases in the process from 10 to 20 mm at transmission of about 90%.
Date: May 28, 2003
Creator: Balbekov, Valeri I.
Object Type: Article
System: The UNT Digital Library
Generation of High Brightness X-Rays with the PLEIADES Thomson X-Ray Source (open access)

Generation of High Brightness X-Rays with the PLEIADES Thomson X-Ray Source

The use of short laser pulses to generate high peak intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. PLEIADES (Picosecond Laser Electron InterAction for Dynamic Evaluation of Structures) is a next generation Thomson scattering x-ray source being developed at Lawrence Livermore National Laboratory (LLNL). Ultra-fast picosecond x-rays (10-200 keV) are generated by colliding an energetic electron beam (20-100 MeV) with a high intensity, sub-ps, 800 nm laser pulse. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm2/mrad2. Simulations of the electron beam production, transport, and final focus are presented. Electron beam measurements, including emittance and final focus spot size are also presented and compared to simulation results. Measurements of x-ray production are also reported and compared to theoretical calculations.
Date: May 28, 2003
Creator: Brown, W J; Anderson, S G; Barty, C P J; Crane, J K; Cross, R R; Fittinghoff, D N et al.
Object Type: Article
System: The UNT Digital Library
Electrical Impedance Tomography at the A-014 Outfall for Detection of DNAPL (open access)

Electrical Impedance Tomography at the A-014 Outfall for Detection of DNAPL

Some laboratory studies (e.g., Olheoft, unpublished report 2001) have shown that the low frequency electrical properties of some soil minerals contaminated by dense non-aqueous phase liquid (DNAPL) may be sufficiently unique to make it possible to use electrical impedance tomography (EIT) to differentiate normal electrical heterogeneities of the subsurface from DNAPL contamination. The goal of this work is to determine if electrical impedance measurements of the soil and groundwater at a contaminated site can be used to detect the presence and map the distribution of DNAPL. The strategy for achieving this goal is to predict the presence and location of DNAPL from an appropriately processed data set taken at the A-014 outfall site at Savannah River Site, which is suspected of near-surface contamination, and then to compare those predictions with results of sample analysis from the same region. Complete agreement between the predictions and the sampling data will be strong (but not conclusive) evidence that DNAPL contamination alters the subsurface materials in a way that can be detected and mapped using low frequency electrical methods. A total lack of agreement will be interpreted to mean that electrical methods cannot at this time be used to locate contamination. The results will …
Date: May 28, 2003
Creator: Daily, W & Ramirez, A
Object Type: Report
System: The UNT Digital Library
Linearization of the Fermilab recycler high level RF (open access)

Linearization of the Fermilab recycler high level RF

In studying the Recycler high level RF, it was found that at 89 kHz, the lowest frequency required by the system, some nonlinearities in magnitude and phase were discovered. The visible evidence of this was that beam injected in a barrier bucket had a definite slope at the top. Using a network analyzer, the S-parameter S{sub 21} was realized for the overall system and from mathematical modeling a second order numerator and denominator transfer function was found. The inverse of this transfer function gives their linearization transfer function. The linearization transfer function was realized in hardware by summing a high pass, band pass and low pass filter together. The resulting magnitude and phase plots, along with actual beam response will be shown.
Date: May 28, 2003
Creator: Dey, Joseph E; Kubicki, Tom & Reid, John
Object Type: Article
System: The UNT Digital Library
Comparison of the TESLA, NLC and CLIC beam-collimation system performance (open access)

Comparison of the TESLA, NLC and CLIC beam-collimation system performance

This report describes studies performed in the framework of the Collimation Task Force organized to support the work of the International Linear Collider Technical Review Committee. The post-linac beam-collimation systems in the TESLA, JLC/NLC and CLIC linear-collider designs are compared using the same computer code under the same assumptions. Their performance is quantified in terms of beam-halo and synchrotron-radiation collimation efficiency. The performance of the current designs varies across projects, and does not always meet the original design goals. But these comparisons suggest that achieving the required performance in a future linear collider is feasible.
Date: May 28, 2003
Creator: Drozhdin, Alexandr I; Blair, Grahame & Keller, Lewis P
Object Type: Article
System: The UNT Digital Library
New neutron cross section and fission yield data for SNManalysis (open access)

New neutron cross section and fission yield data for SNManalysis

Neutron cross-section data are fundamental for the design ofnuclear interrogation systems, the maintenance of nuclear materials andwaste, and the understanding the consequences of nuclear catastrophe.Although a large body of nuclear data exists, it is often old,unreliable, or poorly determined. For several years we have collaborated,as part of an IAEA Coordinated Research Project, to precisely measure thepartial thermal neutron gamma ray cross sections for all elements fromhydrogen to uranium at the Budapest Reactor. These data will replace theunreliable tables of Lone et al [1], still widely in use, and will bepublished as an IAEA TECDOC.
Date: May 28, 2003
Creator: Firestone, R. B.; Molnar, G. L.; Revay, Zs. & Belgya, T.
Object Type: Report
System: The UNT Digital Library
Geochemistry of Samples from Borehole C3177(299-E24-21) (open access)

Geochemistry of Samples from Borehole C3177(299-E24-21)

This report contains the results of geochemical and physical property analyses of twelve samples from the Immobilized Low-Activity Waste (ILAW) borehole #2. The borehole is in the middle of the 200 East Area, at the northeast corner of the ILAW disposal site.
Date: May 28, 2003
Creator: Horton, Duane G.; Schaef, Herbert T.; Serne, R. Jeffrey; Brown, Christopher F.; Valenta, Michelle M.; Vickerman, Tanya S. et al.
Object Type: Report
System: The UNT Digital Library
Beam physics at Tevatron complex (open access)

Beam physics at Tevatron complex

The challenge of achieving the Tevatron Run II luminosity goal of 3 {center_dot} 10{sup 32} cm{sup -2} s{sup -1} requires high level of engineering and machine operation, good and reliable diagnostics, and clear understanding of the underlying accelerator physics. Recent history demonstrated steady increase of the Tevatron luminosity, which was supported by each of the three listed above items. This report reviews major developments in the accelerator physics, which contributed in the Run II luminosity growth. Present limitations of the luminosity and projections of further luminosity growth are also discussed.
Date: May 28, 2003
Creator: Lebedev, Valeri A.
Object Type: Article
System: The UNT Digital Library
Perfluorinated quaternary ammonium salts of polyoxometalate anions: Fluorous biphasic oxidation catalysis with and without fluorous solvents (open access)

Perfluorinated quaternary ammonium salts of polyoxometalate anions: Fluorous biphasic oxidation catalysis with and without fluorous solvents

Perfluorinated quaternary ammonium cations, [CF{sub 3}(CF{sub 2}){sub 7}(CH{sub 2}){sub 3}]{sub 3}CH{sub 3}N{sup +} (RFN{sup +}), were synthesized and used as counter cations for the [WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW{sub 9}O{sub 34}){sub 2}]{sup 12-} (M = Mn(II), Zn(II)), polyoxometalate. The (RFN{sup +}){sub 12}[WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW9O{sub 34}){sub 2}] compounds were fluorous biphasic catalysts for alcohol and alkenol oxidation, and alkene epoxidation with aqueous hydrogen peroxide. Reaction protocols with or without a fluorous solvent were tested. The catalytic activity and selectivity was affected both by the hydrophobicity of the solvent and the substrate.
Date: May 28, 2003
Creator: Maayan, Galia; Fish, Richard H. & Neumann, Ronny
Object Type: Report
System: The UNT Digital Library
Tailored Assays for the Detection of Agroterrorism Viral Agents (open access)

Tailored Assays for the Detection of Agroterrorism Viral Agents

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Date: May 28, 2003
Creator: Messenger, Sharon; McCready, Paula; Smith, Kimothy; Skowrowski, Evan; McKenna, Tom; Heckert, Robert et al.
Object Type: Article
System: The UNT Digital Library
DIE Deflection Modeling: Empirical Validation and Tech Transfer (open access)

DIE Deflection Modeling: Empirical Validation and Tech Transfer

This report summarizes computer modeling work that was designed to help understand how the die casting die and machine contribute to parting plane separation during operation. Techniques developed in earlier research (8) were applied to complete a large computational experiment that systematically explored the relationship between the stiffness of the machine platens and key dimensional and structural variables (platen area covered, die thickness, platen thickness, thickness of insert and the location of the die with respect to the platen) describing the die/machine system. The results consistently show that there are many significant interactions among the variables and it is the interactions, more than the individual variables themselves, which determine the performance of the machine/die system. That said, the results consistently show that it is the stiffness of the machine platens that has the largest single impact on die separation.
Date: May 28, 2003
Creator: Miller, R. Allen
Object Type: Report
System: The UNT Digital Library
Qualitative Reasoning for Additional Die Casting Applications (open access)

Qualitative Reasoning for Additional Die Casting Applications

If manufacturing incompatibility of a product can be evaluated at the early product design stage, the designers can modify their design to reduce the effect of potential manufacturing problems. This will result in fewer manufacturing problems, less redsign, less expensive tooling, lower cost, better quality, and shorter development time. For a given design, geometric reasoning can predict qualitatively the behaviors of a physical manufacturing process by representing and reasoning with incomplete knowledge of the physical phenomena. It integrates a design with manufacturing processes to help designers simultaneously consider design goals and manufacturing constraints during the early design stage. The geometric reasoning approach can encourage design engineers to qualitatively evaluate the compatibility of their design with manufacturing limitations and requirements.
Date: May 28, 2003
Creator: Miller, R. Allen; Cui, Dehua & Ma, Yuming
Object Type: Report
System: The UNT Digital Library
Impedances of Tevatron separators (open access)

Impedances of Tevatron separators

The impedances of the Tevatron separators are revisited and are found to be negligibly small in the few hundred MHz region, except for resonances at 22.5 MHz. The later are contributions from the power cables which may drive head-tail instabilities if the bunch is long enough.
Date: May 28, 2003
Creator: Ng, K. Y.
Object Type: Article
System: The UNT Digital Library
Laboratory Measurements of the Unsaturated Hydraulic Properties at the Vadose Zone Transport Field Study Site (open access)

Laboratory Measurements of the Unsaturated Hydraulic Properties at the Vadose Zone Transport Field Study Site

This report presents sampling and measurement procedures and measurement results for 60 samples from the S-1, S-2, and S-3 bore holes at the Vadose Zone Transport Field Study Leak Simulation Test Site, located at the Sisson and Lu (1984) injection site in the 200 East Area of the Hanford Site. Measured data include particle size distributions (19 points), bulk densities (and bulk density-derived porosity), water retention characteristics (16 static points), and saturated and unsaturated hydraulic conductivities. The coring and sub-sampling procedures led to partially, and occasionally completely, disturbed samples. Textural analyses showed that most of the samples could be classified as sand, some as loamy sands, and two as sandy loams. The multi-step outflow method failed for seven samples, yielding 53 samples for which hydraulic parameters were available. Van Genuchten and Brooks-Corey water retention parameters were determined using static retention points (derived from multi-step outflow time series). Inverse analyses of the multi-step outflow data yielded additional unsaturated hydraulic conductivity parameters. Unfortunately, the inverse analyses had some problems in reaching stable solutions. Therefore, we sometimes fixed saturated and residual water contents and saturated hydraulic conductivities at initial values. Even then, it was not possible to reach a solution for two samples …
Date: May 28, 2003
Creator: Schaap, Marcel G.; Shouse, Pete J. & Meyer, Philip D.
Object Type: Report
System: The UNT Digital Library
Atlas Breached Waste Package and Drip Shield Experiments: Breached Drip Shield Tests (open access)

Atlas Breached Waste Package and Drip Shield Experiments: Breached Drip Shield Tests

The Engineered Barrier System (EBS) represents one system in the performance of the Yucca Mountain high-level radioactive waste (HLW) repository to isolate and prevent the transport of radionuclides from the site to the accessible environment. Breached Waste Package and Drip Shield Experiments (BWPDSE) were performed at the Department of Energy's National Nuclear Security Administration Nevada Support Facility in North Las Vegas, NV in the A-1 lowbay between May 2, 2002 and July 25, 2002. Data collected from the BWPDSE will be used to support the flux splitting model used in Analysis and Modeling Report ANL-WIS-PA-000001 REV 00 ICN 03 ''EBS Radionuclide Transport Abstraction'' (BSC 2001a). Tests were conducted by dripping water from heights representing the drift crown or wall on a full-scale section of a drip shield with both smooth and rough surfaces. The drip shields had machined square breaches that represent the general corrosion breaches or nodes in the ''WAPDEG Analysis of Waste Package and Drip Shield Degradation'' AMR (CRWMS M&O 2000d). Tests conducted during the BWPDSE included: initial tests to determine the splash radius distances and spread factor from the line of drip impact, single patch tests to determine the amount of water collected in target breaches from …
Date: May 28, 2003
Creator: Walton, Z. P.
Object Type: Report
System: The UNT Digital Library
Tevatron beam-beam simulations at injection energy (open access)

Tevatron beam-beam simulations at injection energy

Major issues at Tevatron injection are the effects of 72 long-range beam-beam interactions together with the machine nonlinearity on protons and anti-protons. We look at particle tracking calculations of Dynamic Aperture (DA) under present machine conditions. Comparisons of calculations with observations and experiments are also presented in this report.
Date: May 28, 2003
Creator: Xiao, Meiqin; Erdelyi, Bela & Sen, Tanaji
Object Type: Article
System: The UNT Digital Library
Simulations of octupole compensation of head-tail instability at the Tevatron (open access)

Simulations of octupole compensation of head-tail instability at the Tevatron

The proton lifetime in the Tevatron depends sensitively on chromaticities. Too low chromaticities can make the beam unstable due to the weak head-tail instability. One way to compensate this effect is to introduce octupoles to create a larger amplitude dependent betatron tune spread. However, the use of octupoles will also introduce additional side effects such as second order chromaticity, differential tune shifts and chromaticities on both proton and anti-proton helices. The non-linear effects may also reduce the dynamic aperture. There are 67 octupoles in 4 different circuits in the Tevatron which may be used for this purpose. We report on a simulation study to find the best combinations of polarities and strengths of the octupoles.
Date: May 28, 2003
Creator: Xiao, Meiqin; Sen, Tanaji & Schmidts, Frank
Object Type: Article
System: The UNT Digital Library
Development of a longitudinal density monitor for storage rings (open access)

Development of a longitudinal density monitor for storage rings

We report on development of a new storage ring operations tool for measurement of longitudinal beam density profile. The technique mixes synchrotron light with light from a mode locked solid-state laser oscillator in a non-linear crystal and detects the up-converted radiation with a photo-multiplier. The laser is phase locked to the storage ring RF system. The laser choices available for repetition frequency, pulse length and phase modulation give a very wide range of options for matching the bunch configuration of particular storage rings. Progress in the technology of solid-state lasers ensures this system can be made robust for routine use in storage ring operations. A very large number of important applications are possible including measurement of the fraction of untrapped particles prior to acceleration, the population of particles in the nominally unfilled RF buckets in a bunch train (''ghost bunches''), longitudinal tails, the diffusion of particles into the beam abort gap and th e normal bunch parameters of longitudinal shape and intensity. We are currently investigating application to two devices: (1) the 1.9 GeV ALS electron storage ring at LBNL with 328 RF buckets, 2ns bucket spacing, 276 nominally filled bunches, 15-30ps rms bunch length and (2) the 7 TeV …
Date: May 28, 2003
Creator: Zolotorev, M.; Beche, J.-F.; Byrd, J.; Datte, P.; De Santis, S.; Denes, P. et al.
Object Type: Article
System: The UNT Digital Library
Accelerator related backgrounds in the LHC forward detectors (open access)

Accelerator related backgrounds in the LHC forward detectors

Detailed Monte Carlo simulations are performed on radiation environment in the LHC IP5 interaction region at the locations of the TOTEM Roman Pots proposed to detect particles produced at very small angles in the elastic scattering and diffraction dissociation processes at the LHC. Radiation loads on these detectors are calculated with the MARS14 code both of the pp-collision origin and beam loss related (beam-gas and tails from collimators).
Date: May 28, 2003
Creator: al., Nikolai V. Mokhov et
Object Type: Article
System: The UNT Digital Library
Energy deposition limits in a Nb3Sn separation dipole in front of the LHC high-luminosity inner triplet (open access)

Energy deposition limits in a Nb3Sn separation dipole in front of the LHC high-luminosity inner triplet

Interaction region inner triplets are among the systems which may limit the LHC performance. An option for a new higher luminosity IR is a double-bore inner triplet with separation dipoles placed in front of the first quadrupole. The radiation load on the first dipole, resulting from pp-interactions, is a key parameter to determine the feasibility of this approach. Detailed energy deposition calculations were performed with the MARS14 code for two Nb{sub 3}Sn dipole designs with no superconductor on the mid-plane. Comparison of peak power densities with those in the baseline LHC IR suggests that it may be possible to develop workable magnets for luminosities up to 10{sub 35} cm{sup -2} s{sup -1}.
Date: May 28, 2003
Creator: al., Nikolai V. Mokhov et
Object Type: Article
System: The UNT Digital Library
Fermilab booster beam collimation and shielding (open access)

Fermilab booster beam collimation and shielding

The beam power in the upgraded Booster at 8 GeV and 10 Hz will be 64 kW. Beam loss can result in high radiation loads in the ring. The purpose of a new beam halo cleaning system is to localize proton losses in specially shielded regions. Calculations show that this 2-stage collimation system will localize about 99% of beam loss in straight sections 6 and 7 and immediately downstream. Beam loss in the rest of the machine will be on average 0.1W/m. Local shielding will provide tolerable prompt and residual radiation levels in the tunnel, above the tunnel at the surface and in the sump water. Results of thorough MARS calculations are presented for a new design which includes shielding integrated with the collimators, motors and controls ensuring a high performance and facilitating maintenance. First measurements of the collimation efficiency are presented.
Date: May 28, 2003
Creator: al., Nikolai V. Mokhov et
Object Type: Article
System: The UNT Digital Library
Mitigation of effects of beam-induced energy deposition in the LHC high-luminosity interaction regions (open access)

Mitigation of effects of beam-induced energy deposition in the LHC high-luminosity interaction regions

Beam-induced energy deposition in the LHC high luminosity interaction region components is one of the serious limits for the machine performance. The results of further optimization and comprehensive MARS14 calculations in the IP1 and IP5 inner and outer triplets are summarized for the updated lattice, calculation model, baseline pp-collision source term, and for realistic engineering constraints on the hardware design. It is shown that the optimized layout and absorbers would provide a sufficient reduction of peak power density and dynamic heat load in the superconducting components with an adequate safety margin. Accumulated dose and residual dose rates in and around the region components are also kept below the tolerable limits in the proposed design.
Date: May 28, 2003
Creator: al., Nikolai V. Mokhov et
Object Type: Article
System: The UNT Digital Library