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Study of ICRF wave propagation and plasma coupling efficiency in a linear magnetic mirror device

Ion Cyclotron Range of Frequency (ICRF) wave propagation in an inhomogeneous axial magnetic field in a cylindrical plasma-vacuum system has historically been inadequately modelled. Previous works either sacrifice the cylindrical geometry in favor of a simpler slab geometry, concentrate on the resonance region, use a single mode to represent the entire field structure, or examine only radial propagation. This thesis performs both analytical and computational studies to model the ICRF wave-plasma… more

Date: July 1, 1991

Creator: Peng, S.Y.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Radioactivities of Long Duration Exposure Facility (LDEF) materials: Baggage and bonanzas

Radioactivities in materials onboard the returned Long Duration Exposure Facility (LDEF) satellite have been studied by a variety of techniques. Among the most powerful is low-background Ge-semiconductor detector gamma-ray spectrometry, illustrated here by results obtained at the Lawrence Berkeley Laboratory's (LBL) Low Bakground Facilities, in a multi-laboratory collaboration coordinated by Dr. Thomas Parnell's team at the Marshall Spacecraft Center, Huntsville, Alabama.

Date: August 1, 1991

Creator: Smith, A. R. & Hurley, D. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Future aircraft and potential effects on stratospheric ozone and climate

The purpose of this study is to extend the recent research examining the global environmental effects from potential fleets of subsonic and supersonic commercial aircraft. Initial studies with LLNL models of global atmospheric chemical, radiative, and transport processes have indicated that substantial decreases in stratospheric ozone concentrations could result from emissions of NO{sub x} from aircraft flying in the stratosphere, depending on fleet size and magnitude of the engine emissions. T… more

Date: October 1, 1991

Creator: Kinnison, D.E. & Wuebbles, D.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Quantitative analysis of bidirectional electron fluxes within coronal mass ejections at 1 AU

The solar wind electron heat flux is carried primarily by suprathermal halo'' electrons beamed antisunward along the interplanetary magnetic field (IMF), indicating magnetic connection to the Sun only in one direction. However, electron observations at 1 AU show that counterstreaming halo beams, suggesting closed magnetic structures, prevail within coronal mass ejections (CMEs). These structures might be magnetic tongues'', tied to the Sun at both ends, magnetically detached plasmoids, or compl… more

Date: January 1, 1991

Creator: Phillips, J.L.; Gosling, J.T.; McComas, D.J.; Bame, S.J. & Feldman, W.C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development of ultra pure germanium epi layers for blocked impurity band far infrared detectors

The main goals of this paper are: (1) To develop a low-pressure CVD (LPCVD) process that allows epitaxial growth at lower temperatures. Lower temperatures will allow the achievement of a sharp dopant profile at the substrate/epi-layer interface. Less out-diffusion from the substrate would allow the use of thinner epitaxial layers, which would lead to a larger depletion width in the photoactive region. LPCVD also avoids, to a great extent, gas-phase nucleation, which would cause Ge particulates … more

Date: May 1, 1991

Creator: Lutz, M.P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Electrochemical energy storage using PEM systems

This paper gives the results of an engineering assessment for future, long-lived space power systems for extraterrestrial applications. Solar-based, regenerative fuel cell power plants formed from either alkaline or PEM components are the focus. Test results on advanced PEM fuel cell stack components are presented. 7 refs., 4 figs., 1 tab.

Date: January 1, 1991

Creator: Vanderborgh, N. E.; Hedstrom, J. C. & Huff, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Booster Applications Facility report, Phase 2

This report summarizes studies and planning performed by Brookhaven National Laboratory (BNL) personnel at the request of NASA for the design, construction and operation of experimental areas and facilities for utilization of ion beams from the BNL Booster synchrotron particle accelerator. These facilities would be primarily utilized to simulate space radiation for radiobiological research, shielding studies and detector calibrations. The feasibility of such a project has been established, prel… more

Date: June 1, 1991

Creator: Thieberger, P. (ed.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Status of the Advanced Stirling Conversion System Project for 25 kW dish Stirling applications

Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for terrestrial Solar Heat Receivers. The Stirling engine has been identified by Sandia as one of the most promising heat engines for terrestrial applications. The Stirling engine also has the potential to meet DOE's performance and cost goals. The NASA Lewis Research Center is conducting technology development for Stirling convertors directed toward a dynamic power s… more

Date: January 1, 1991

Creator: Shaltens, R.K. & Schreiber, J.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurements of induced radioactivity in some LDEF samples

Twenty-six stainless steel trunnion samples, five aluminum end support retainer plate samples, two aluminum keel plate samples, and two titanium clips were analyzed. The shielded high-purity germanium detectors used had efficiencies of 33%, 54%, and 80% at 1332 keV. Detector efficiencies as a function of energy and corrections for self-absorption in the samples were determined with calibrated sources and unactivated control samples. Several measurements were made on most samples. In the trunnio… more

Date: January 1, 1991

Creator: Moss, C. E. & Reedy, R. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

In situ observations of coronal mass ejections in interplanetary space

Coronal mass ejections, CMEs, in the solar wind at 1 AU generally have distinct plasma and field signatures by which they can be distinguished from the ordinary solar wind. These include one or more of the following: helium abundance enhancements, ion and electron temperature depressions, unusual ionization states, strong magnetic fields, low plasma beta, low magnetic field variance, coherent field rotations, counterstreaming (along the field) energetic protons, and counterstreaming supratherma… more

Date: January 1, 1991

Creator: Gosling, J. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The Ulysses solar wind plasma investigation: Description and initial in-ecliptic results

During the in-ecliptic flight of Ulysses from the Earth toward its encounter with Jupiter, the Los Alamos solar wind plasma experiment has performed well. Briefly described, the instrumentation contains two independent electrostatic analyzers, one for ions and one for electrons. Initial analysis of solar wind electron core temperatures obtained between 1.15 and 3.76 AU yields a gradient of T {proportional to} R{sup {minus}0.7} which is flatter than expected for adiabatic expansion of a single-t… more

Date: January 1, 1991

Creator: Bame, S.J.; Phillips, J.L.; McComas, D.J.; Gosling, J.T. (Los Alamos National Lab., NM (United States)) & Goldstein, B.E. (Jet Propulsion Lab., Pasadena, CA (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Lessons learned from pilot errors using automated systems in advanced technology aircraft

The National Aeronautics and Space Administration (NASA) sponsored a project at the Idaho National Engineering Laboratory (INEL) to investigate pilot errors that occur during interaction with automated systems in advanced technology ( glass cockpit'') aircraft. In particular, we investigated the causes and potential corrective measures for pilot errors that resulted in altitude deviation incidents (i.e. failure to capture or maintain the altitude assigned by air traffic control). To do this, we… more

Date: January 1, 1993

Creator: Nelson, W. R.; Byers, J. C.; Haney, L. N.; Ostrom, L. T. & Reece, W. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Application of neutron diffraction technology to the determination of residual strain in engineering composites

Knowledge of fabrication induced residual stresses in the fiber and matrix of advanced engineering composites is important as these stresses can greatly influence the mechanical properties of these composites. In this paper, the application of neutron diffraction technology to the determination of thermal residual strains in the constituents of composites (from which stresses can be calculated) is discussed. Experimental determination of temperature dependent strain in the fiber and matrix of t… more

Date: January 1, 1992

Creator: Kupperman, D. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The effects of gravity on wrinkled laminar flames

Laminar and turbulent conical Bunsen type flames were used. The study compares results from normal gravity with the burner in an up-right orientation (+g), the burner inverted (-g), and in microgravity ([mu]g) by using the NASA Lewis drop tower facility. The primary diagnostic is a laser schlieren system and some LDA measurements were taken for the +g condition to measure the flow field. The +g laminar flame experiences a large amount of instabilities and results in an unsteady flame tip; cause… more

Date: September 1, 1992

Creator: Kostiuk, L.W.; Zhou, L. & Cheng, R.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Single track effects, biostack and risk assessment

This talk addresses the single-track nature of the space radiation environment, and points out the importance of single hits'' in the evaluation of radiation risk for long-term missions occurring outside the earth's magnetic field. A short review is made of biological objects found to show increased effects when hit'' by a single heavy charged-particle in space. A brief discussion is given of the most provocative results from the bacterial spore B. subtilis: experimental evidence that tracks ca… more

Date: October 1, 1992

Creator: Curtis, S.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Application of neutron diffraction technology to the determination of residual strain in engineering composites

Date: December 1, 1992

Creator: Kupperman, D. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The influence of CDM on the dynamical estimate of {Omega} in the local neighborhood

Peebles has suggested an interesting method to trace back in time positions of galaxies called the least action method. This method applied on the Local Group galaxies seems to indicate that we live in an {Omega}{approx} 0.1 Universe. We have studied a CDM N-body simulation with {Omega} = 0.2 and H = 50kms{sup {minus}1}/Mpc and compare trajectories traced back from the Least Action Principle and the center of mass of the particle forming CDM halos. We have shown that the agreement between these… more

Date: December 31, 1994

Creator: Dunn, A. M. & Laflamme, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The second coming of cold dark matter?

While the standard cold dark matter (CDM) model has received numerous marks against it on the basis of a variety of observational data, the prediction of high {Sigma}{Upsilon}, the pairwise-velocity dispersion between galaxies, on small (megaparsec) scales was reported as perhaps one of its greatest failings. Here, we reexamine the case of CDM and {Sigma}{Upsilon}, with high-resolution numerical simulations. The statistic was measured in simulations, in artificial galaxy catalogs, and in the Cf… more

Date: December 31, 1994

Creator: Zurek, W. H.; Bromley, B. C. & Warren, M. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Lessons learned from pilot errors using automated systems in advanced technology aircraft

The National Aeronautics and Space Administration (NASA) sponsored a project at the Idaho National Engineering Laboratory (INEL) to investigate pilot errors that occur during interaction with automated systems in advanced technology (``glass cockpit``) aircraft. In particular, we investigated the causes and potential corrective measures for pilot errors that resulted in altitude deviation incidents (i.e. failure to capture or maintain the altitude assigned by air traffic control). To do this, w… more

Date: April 1, 1993

Creator: Nelson, W. R.; Byers, J. C.; Haney, L. N.; Ostrom, L. T. & Reece, W. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Single track effects, biostack and risk assessment

This talk addresses the single-track nature of the space radiation environment, and points out the importance of single ``hits`` in the evaluation of radiation risk for long-term missions occurring outside the earth`s magnetic field. A short review is made of biological objects found to show increased effects when ``hit`` by a single heavy charged-particle in space. A brief discussion is given of the most provocative results from the bacterial spore B. subtilis: experimental evidence that track… more

Date: October 1, 1992

Creator: Curtis, S. B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Heat pipe radiation cooling (HPRC) for high-speed aircraft propulsion. Phase 2 (feasibility) final report

The National Aeronautics and Space Administration (NASA), Los Alamos National Laboratory (Los Alamos), and CCS Associates are conducting the Heat Pipe Radiation Cooling (HPRC) for High-Speed Aircraft Propulsion program to determine the advantages and demonstrate the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This innovative approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the e… more

Date: March 25, 1994

Creator: Martin, R. A.; Merrigan, M. A.; Elder, M. G.; Sena, J. T.; Keddy, E. S. & Silverstein, C. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Relativistic electrons in the outer-zone: An 11 year cycle, their relation to the solar wind

We examine Los Alamos energetic electron data from 1979 through the present to show long term trends in the trapped relativistic electron populations at geosynchronous-earth-orbit (GEO). Data is examined from several CPA and SOPA instruments to cover the interval from 1979 through June 1994. It is shown that the higher energy electrons fluxes (E > 300 keV) displayed a cycle of {approx}11 years. In agreement with other investigators, we also show that the relativistic electron cycle is out of ph… more

Date: December 31, 1994

Creator: Belian, R. D.; Cayton, T. E.; Christensen, R. A.; Ingraham, J. C.; Meier, M. M.; Reeves, G. D. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Project report: Aircraft

Analyses of scenarios of past and possible future emissions are an important aspect of assessing the potential environmental effects from aircraft, including the proposed high speed civil transport (HSCT). The development of a detailed three-dimensional database that accurately represents the integration of all aircraft emissions along realistic flight paths for such scenarios requires complex computational modeling capabilities. Such a detailed data set is required for the scenarios evaluated … more

Date: April 1, 1994

Creator: Wuebbles, D. J.; Baughcum, S.; Metwally, M. & Seals, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Beam-powered lunar rover design

Manned exploration of our nearest neighbors in the solar systems is the primary goal of the Space Exploration Initiative (SEI). An integral part of any manned lunar or planetary outpost will be a system for manned excursions over the surface of the planet. This report presents a preliminary design for a lunar rover capable of supporting four astronauts on long-duration excursions across the lunar landscape. The distinguishing feature of this rover design is that power is provided to rover via a… more

Date: March 1, 1992

Creator: Dagle, J. E.; Coomes, E. P.; Antoniak, Z. I.; Bamberger, J. A.; Bates, J. M.; Chiu, M. A. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department