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July 29, 2977 magnetic storm: observations and modeling of energetic particles at synchronous orbit (open access)

July 29, 2977 magnetic storm: observations and modeling of energetic particles at synchronous orbit

A brief description of the energetic particle studies carried out by Subgroup 6 of CDAW-2 is presented. Instrumentation onboard six spacecraft at (or near) geostationary orbit was used in the analysis. Timing of particle injection during the last, and largest, substorm on July 29, 1977 (approx. 1200 UT) was investigated, as was the particle phase space density variation associated with this event. Energetic proton gradient anisotropies were also used to examine large-scale magnetospheric boundary motions. Finally, adiabatic modeling calculations were performed for the substorm event period, including effects of injection, convection, corotation, and particle drifts. We find substantial evidence to suggest storage of solar wind-derived energy in the magnetotail prior to the substorm and we find this stored energy to be suddenly released at substorm expansion onset. We also find particles at geostationary orbit to be newly accelerated during the substorm to energies greater than or equal to 1 MeV (..mu.. greater than or equal to 100 MeV/G) and modeling shows that these particles could have been convected (and injected) from beyond 10 R/sub E/ in the nightside magnetosphere.
Date: January 1, 1981
Creator: Baker, D.N.; Fritz, T.A. & Wilken, B.
System: The UNT Digital Library
Electronic structure of molecules using relativistic effective core potentials (open access)

Electronic structure of molecules using relativistic effective core potentials

Starting with one-component Cowan-Griffin relativistic Hartree-Fock orbitals, which successfully incorporate the mass-velocity and Darwin terms present in more complicated wavefunctions such as Dirac-Hartree-Fock, one can derive relativistic effective core potentials (RECP's) to carry out molecular calculations. These potentials implicitly include the dominant relativistic terms for molecules while allowing one to use the traditional quantum chemical techniques for studying the electronic structure of molecules. The effects of spin-orbit coupling can then be included using orbitals from such calculations using an effective 1-electron, 1-center spin-orbit operator. Applications to molecular systems involving heavy atoms, show good agreement with available spectroscopic data on molecular geometries and excitation energies.
Date: January 1, 1981
Creator: Hay, P.J.
System: The UNT Digital Library
Effects of low-energy-electron-capture collisions (H/sub 0/ + c/sup n+/) on the particle and energy balance of tokamak plasmas (open access)

Effects of low-energy-electron-capture collisions (H/sub 0/ + c/sup n+/) on the particle and energy balance of tokamak plasmas

To illustrate the way in which atomic data provides enlightenment in the search for understandable (and thus extrapolable) confinement models, we restrict our scope to electron capture collisions involving H/sub 0/ and multiply-charged ions. Many such foreign (impurity) multiply-charged ion species are found in plasma discharges, as a result of gas recycling and damage to the surrounding surfaces by energetic plasma particles. Typical low-Z ions are carbon and oxygen; the major constituents of the stainless steel wall (Fe, Ni, Cr) are intermediate impurities, while high-Z impurities (Mo, W) enter from limiter plates which constrict the hot plasma zone to reduce direct plasma-wall contact. In this discussion, however, attention will be given only to applications of data involving H/sub 0/ + C/sup n+/ ..-->.. H/sup +/ + C/sup (n-1)+/ reactions with energy 10 eV to 2 keV. This energy range is typical of the plasma edge in present devices.
Date: January 1, 1981
Creator: Hogan, J. T.
System: The UNT Digital Library
Injection locking of excimer lasers (open access)

Injection locking of excimer lasers

Reliable injection locking of high-power unstable resonator excimer lasers can be achieved with extremely low reference oscillator power. The criteria for injection locking are discussed and experimental results are given.
Date: January 1, 1981
Creator: Bigio, I.J. & Slatkine, M.
System: The UNT Digital Library
Abstracts of papers to be presented at the fifth symposium on x- and gamma-ray sources and applications (open access)

Abstracts of papers to be presented at the fifth symposium on x- and gamma-ray sources and applications

The program and abstracts of papers are presented. Topics include radiation sources, radiation detectors, mathematical models and data analysis, gamma-ray spectroscopy, instrumentation, applications of x-ray fluorescence, PIXE, and x-ray absorption. (ACR)
Date: January 1, 1981
Creator: unknown
System: The UNT Digital Library
Energy optimization in DOD facilities (open access)

Energy optimization in DOD facilities

A static linear programming formulation (management tool) of energy optimization problems on military bases has been developed to assist each of the military services in their planning activities and budgetary allocation decisions. Several objective functions have been defined, resulting in two types of model capabilities: minimization of capital costs (investments) subject to a number of energy and dollar constraints and the maximization of energy savings subject to capital and operating fund budget restrictions and minimum energy performance goals. The management tool defines various levels of aggregation in terms of: (1) geographical boundaries; (2) end-use energy demand; (3) building type characteristics; (4) conservation options; (5) renewable energy and alternative fuel technologies; and (6) a limited set of advanced energy technology options. Both a technical description of and a user's guide to the principal model components and operational attributes of the constructed DOD energy optimization model are presently being prepared. Two key questions are briefly reviewed within the context of preliminary results obtained from application of the developed model to two Air Force Logistics Command installations: (1) the geographical distribution of military construction dollars under a set of budgetary and energy performance constraints; and (2) the selection of energy supply technologies - …
Date: January 1, 1981
Creator: Roach, F.; Kirschner, C. & Salmon, R.
System: The UNT Digital Library
Relevance of long-term carcinogenic and genetic hazards to emergency control (open access)

Relevance of long-term carcinogenic and genetic hazards to emergency control

This paper concentrates on how various factors may influence the risk estimates for human exposure to ionizing radiations in general, rather than on one specific nuclear event on a model population. Discussion is related to exposures to external low linear energy transfer radiation and the various parameters that affect human response. (PSB)
Date: January 1, 1981
Creator: Fry, R.J.M.
System: The UNT Digital Library
Net-energy analysis of a retrofit geothermal-heating system (open access)

Net-energy analysis of a retrofit geothermal-heating system

A net energy analysis was carried out as part of a study of the potential engineering and economic feasibility for geothermal heating of the campus of the University of New Mexico in Albuquerque. The geothermal system design included production and disposal wells, surface facilities and retrofitting of eighteen existing buildings. For a 30-year project life, the net energy ratio was found to be about 7.1.
Date: January 1, 1981
Creator: Kauffman, D.; Houghton, A.V. & Kuo, W.S.
System: The UNT Digital Library
Nuclear waste/nuclear power: their futures are linked (open access)

Nuclear waste/nuclear power: their futures are linked

This paper briefly reviews current aspects of radioactive waste disposal techniques and transportation. Addressed are high-level and low-level radioactive wastes, interim spent fuel storage and transportation. The waste options being explored by DOE are listed. Problems of public acceptance will be more difficult to overcome than technical problems. (DMC)
Date: January 1, 1981
Creator: Skoblar, L.T.
System: The UNT Digital Library
Large source test stand for H/sup -/(D/sup -/) ion source (open access)

Large source test stand for H/sup -/(D/sup -/) ion source

The Brookhaven National Laboratory Neutral Beam Group has constructed a large source test stand for testing of the various source modules under development. The first objective of the BNL program is to develop a source module capable of delivering 10A of H/sup -/(D/sup -/) at 25 kV operating in the steady state mode with satisfactory gas and power efficiency. The large source test stand contains gas supply and vacuum pumping systems, source cooling systems, magnet power supplies and magnet cooling systems, two arc power supplies rated at 25 kW and 50 kW, a large battery driven power supply and an extractor electrode power supply. Figure 1 is a front view of the vacuum vessel showing the control racks with the 36'' vacuum valves and refrigerated baffles mounted behind. Figure 2 shows the rear view of the vessel with a BNL Mk V magnetron source mounted in the source aperture and also shows the cooled magnet coils. Currently two types of sources are under test: a large magnetron source and a hollow cathode discharge source.
Date: January 1, 1981
Creator: Larson, R. & McKenzie-Wilson, R.
System: The UNT Digital Library
Roles of complex and simple terrain in the estimation of atmospheric diffusion (open access)

Roles of complex and simple terrain in the estimation of atmospheric diffusion

The highly specialized yet integrated requirements for theory, numerical modeling, and field experiments have led to the organization of teams that incorporate different specialties around a shared objective. This paper attempts to establish a context for the dominant terrain effects including the role of vegetative cover. Some practical needs for a thorough understanding of terrain influence are explored, some of the phenomena that have been identified as complicating the transport and diffusion of pollutants are reviewed. A variety of methods that have been used to characterize the topography itself for atmospheric transport applications are reviewed.
Date: January 1, 1981
Creator: Barr, S.
System: The UNT Digital Library
Selected etching and annealing properties of Brazilian quartz crystals for solid state track recorder applications (open access)

Selected etching and annealing properties of Brazilian quartz crystals for solid state track recorder applications

The etching and annealing properties of Brazilian quartz crystals are under investigation to determine their suitability for use as solid state track recorders (SSTR) and damage monitors in nuclear reactor environments, where temperatures and neutron fluences are high. Observer objectivity in counting fission tracks has been established at the 1 to 2% level, and a method of standardizing chemical etching from one sample of quartz to another has been found. A method has also been found to make corrections for track loss due to thermal annealing in terms of the effect of the annealing on the track size in the direction of maximum bulk etch rate parallel to the 100 plane, provided the fractional track loss does not exceed approx. 40%.
Date: January 1, 1981
Creator: Roberts, J.H.; Gold, R. & Ruddy, F.H.
System: The UNT Digital Library
Count rate performance of a microchannel plate photomultiplier (open access)

Count rate performance of a microchannel plate photomultiplier

The count rate dependent gain change of a microchannel plate photomultiplier has been measured. Gain changes of 60% have been observed for count rates in excess of 2 x 10/sup 5/ s/sup -1/. The microchannel plate photomultiplier was used as a multiplying element of a scintillation detector system using NaI(Tl) as the scintillator. Data are compared to a simplified model of this form of photomultiplier.
Date: January 1, 1981
Creator: Nieschmidt, E.B.; Lawrence, R.S.; Gentillon, C.D. & Vegors, S.H. Jr.
System: The UNT Digital Library
Sagittal focusing of synchrotron x radiation with curved crystals (open access)

Sagittal focusing of synchrotron x radiation with curved crystals

We describe the sagittal focusing of x rays with singly bent crystals that accept the meridian plane divergence from a similar but flat crystal to form a pair in a nondispersive two-crystal Bragg monochromator. Curved crystals can intercept from 5 to 20 times the sagittal divergence of curved mirrors at x-ray energies above 10 keV. Anticlastic (transverse) bending of the crystal is made negligible in the meridian plane with reinforcing ribs cut parallel to the plane of scattering. Results show that at energies of 10, 20, and 30 keV the bent crystal performs efficiently and images the source size at the Cornell High Energy Synchrotron Source.
Date: January 1, 1981
Creator: Sparks, C. J., Jr.; Ice, G. E.; Wong, J. & Batterman, B. W.
System: The UNT Digital Library
Holography at x-ray wavelengths (open access)

Holography at x-ray wavelengths

We discuss alternative holographic techniques for imaging microscopic structures with a short-pulse, high intensity, high-quantum-energy laser. We find that Fresnel transform holography using a photoresist for registration of the hologram is most likely to be within the scope of near term technology. Although it has advantages in time gating, using an in-line electron microscope for hologram registration has an unacceptable tradeoff between quantum efficiency and resolution. Fourier transform holography using a reflector to generate the reference beam might be a reasonable alternative using low resolution film, but is necessarily more complicated. We discuss the dependence of the required laser intensity on the resolution sought and on the elastic and absorption cross sections. We conclude that resonant scattering must be used to obtain holograms at reasonable intensities.
Date: January 1, 1981
Creator: Solem, T. C.; Baldwin, G. C. & Chapline, G. F.
System: The UNT Digital Library
Optimization of electrochemical-etching parameters for highly sensitive CR-39 fast neutron dosimeters (open access)

Optimization of electrochemical-etching parameters for highly sensitive CR-39 fast neutron dosimeters

Voltage gradient and frequency were studied for their influence on the electrochemical etching of CR-39 plastic irradiated with fission spectrum, fast neutrons. A power supply having outputs of up to 1.5 kV (rms) and 5 kHz was used. Differential leakage current measurements under non-etching conditions indicated that the optimal values in electrochemical etching would be 20 kV/cm and 1.3 kHz. That these parameters produced a maximum sensitivity was verified in subsequent electrochemical etching experiments with foils that were both unirradiated and irradiated. The introduction of a proton irradiator cover and a conventional etching step prior to the electrochemical etching, increased the sensitivity to neutrons (approx. 30-fold) and decreased the background track density to 4.4 +- 0.6 tracks/cm/sup 2/. The corresponding sensitivity was then 1.3 tracks/cm/sup 2//mrem with a minimum level of detectability (3sigma) of 1.4 mrem.
Date: January 1, 1981
Creator: Gammage, R.B. & Chowdhury, A.
System: The UNT Digital Library
Measurement of instantaneous shut-in pressure in crystalline rock (open access)

Measurement of instantaneous shut-in pressure in crystalline rock

A method is defined which was found useful, not only for determining the instantaneous shut-in pressure (ISIP) during fracture creation, but also for determining the pressure inside the fracture, near the exit and entrance wellbores, when a circulation of fluid through a fracture is taking place. The basic assumption of the Muskat method is that, after a short transient period, the shut-in pressure approaches an asymptotic value, Pa, in an exponential fashion, i.e., if Pa is subtracted from P at each time, t, and the result is plotted, ln (P-Pa) vs t will be a straight line. Various values of Pa are tried until the best straight line fit is found. Two Muskat analyses are shown. (MHR)
Date: January 1, 1981
Creator: Aamodt, L. & Kuriyagawa, M.
System: The UNT Digital Library
Reactor emergency preparedness: lifesaving or as low as reasonable achievable (open access)

Reactor emergency preparedness: lifesaving or as low as reasonable achievable

An emergency is defined as an unforseen combination of circumstances or the resultant state that calls for immediate action. Although not explicitly indicated, the implication is that the action is intended to protect life, limb and or property from extreme peril. For the most part, the kind and extent of the emergency planning required under current regulations of the USNRC do not appear to be so much related to emergencies (within the above definition) as they do toward the reduction of the off-site radiation doses from uncontrolled releases during reactor accident conditions to as low as reasonably achievable levels. Not only do the latter appear to be of questionable cost-effectiveness, but in their extent and complexity beyond normal disaster planning they may in fact be counter productive to optimum public safety.
Date: January 1, 1981
Creator: Hull, A.P.
System: The UNT Digital Library
Heat transfer modelling of first walls subject to plasma disruption (open access)

Heat transfer modelling of first walls subject to plasma disruption

A brief description of the plasma disruption problem and potential thermal consequences to the first wall is given. Thermal models reviewed include: a) melting of a solid with melt layer in place; b) melting of a solid with complete removal of melt (ablation); c) melting/vaporization of a solid; and d) vaporization of a solid but no phase change affecting the temperature profile.
Date: January 1, 1981
Creator: Fillo, J.A. & Makowitz, H.
System: The UNT Digital Library
QA engineering for the LCP USA magnet manufacturers (open access)

QA engineering for the LCP USA magnet manufacturers

This paper describes the QA and QC efforts and results used in fabricating the superconducting magnets of competing designs being developed by American Manufacturers for testing in the ORNL Large Coil Test Facility. Control of the design, materials and processes to assure proper functioning of the magnets in the test facility as well as the content of archival data being compiled is discussed.
Date: January 1, 1981
Creator: Childress, C.E.; Batey, J.E. & Burn, P.B.
System: The UNT Digital Library
Electronegative gases (open access)

Electronegative gases

Recent knowledge on electronegative gases essential for the effective control of the number densities of free electrons in electrically stressed gases is highlighted. This knowledge aided the discovery of new gas dielectrics and the tailoring of gas dielectric mixtures. The role of electron attachment in the choice of unitary gas dielectrics or electronegative components in dielectric gas mixtures, and the role of electron scattering at low energies in the choice of buffer gases for such mixtures is outlined.
Date: January 1, 1981
Creator: Christophorou, L.G.
System: The UNT Digital Library
Effect of precipitate-matrix interface sinks on the growth of voids in the matrix (open access)

Effect of precipitate-matrix interface sinks on the growth of voids in the matrix

A qualitative discussion of the differing roles played by coherent and incoherent precipitates as point defect sinks is presented. Rate theory is used to obtain semiquantitative estimates of the growth of cavities in the matrix when either type of precipitate is present. Methods for deriving the sink strengths of precipitates of arbitrary shape are developed. In three materials where available microstructural information allows an analysis, precipitates are found to cause only a small relative suppression of cavity growth via the mechanisms here considered.
Date: January 1, 1981
Creator: Brailsford, A.D. & Mansur, L.K.
System: The UNT Digital Library
Learning from numerical calculations of ion-atom collisions (open access)

Learning from numerical calculations of ion-atom collisions

Violent collision of two independent many-particle systems, victims, are discussed in the atomic sphere. The asymmetric region where the charge of the projectile Z/sub p/ is less than the target nuclear charge Z/sub n/ is now well understood though interesting details still need to be worked out. Negatively charged projectiles offer a new illustration of Fadeev re-arrangement collisions. Multi-electron coherence effects illustrate the richness of the field but a symmetric (Z/sub p/ approx. Z/sub n/) collision treatment is needed. A new one and a half center expansion method promises a solution to this problem. Future areas of interest are discussed.
Date: January 1, 1981
Creator: Reading, J.F.; Ford, A.L.; Martir, M. & Becker, R.L.
System: The UNT Digital Library
Role of animal studies in low-dose extrapolation (open access)

Role of animal studies in low-dose extrapolation

Current data indicate that in the case of low-LET radiation linear, extrapolation from data obtained at high doses appears to overestimate the risk at low doses to a varying degree. In the case of high-LET radiation, extrapolation from data obtained at doses as low as 40 rad (0.4 Gy) is inappropriate and likely to result in an underestimate of the risk.
Date: January 1, 1981
Creator: Fry, R.J.M.
System: The UNT Digital Library