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Fluorescent scattering by molecules embedded in small particles. Progress report, February 1, 1981-January 31, 1982 (open access)

Fluorescent scattering by molecules embedded in small particles. Progress report, February 1, 1981-January 31, 1982

In earlier work a model of fluorescent and Raman scattering by active molecules represented as classical electric dipoles embedded in small particles was developed. The intensity and angular distribution of the inelastically scattered radiation was shown to depend on the geometric and optical properties of the particle. The model was originally developed for particles having spherical shape and later extended to concentric spheres, cylinders, and prolate spheroids. The active molecules were originally assumed to be isotropically polarizable. The model has been recently extended to certain types of anisotropically polarizable molecules. The model had also been applied to particles having internal structure.
Date: January 31, 1982
Creator: Chew, H. & McNulty, P.J.
System: The UNT Digital Library
Fusion technology status and requirements (open access)

Fusion technology status and requirements

This paper summarizes the status of fusion technology and discusses the requirements to be met in order to build a demonstration fusion plant. Strategies and programmatic considerations in pursuing engineering feasibility are also outlined.
Date: January 26, 1982
Creator: Thomassen, K.I.
System: The UNT Digital Library
Engineering design of the Nova Laser Facility for inertial-confinement fusion (open access)

Engineering design of the Nova Laser Facility for inertial-confinement fusion

The design of the Nova Laser Facility for inertial confinement fusion experiments at Lawrence Livermore National Laboratory is presented from an engineering perspective. Emphasis is placed upon design-to-performance requirements as they impact the various subsystems that comprise this complex experimental facility.
Date: January 25, 1982
Creator: Simmons, W. W.; Godwin, R. O.; Hurley, C. A.; Wallerstein, E. P.; Whitham, K.; Murray, J. E. et al.
System: The UNT Digital Library
Estimating Adipose Tissue in the Chest Wall Using Ultrasonic and Alternate /sup 40/K and Biometric Measurements (open access)

Estimating Adipose Tissue in the Chest Wall Using Ultrasonic and Alternate /sup 40/K and Biometric Measurements

The percentage of adipose (fat) tissue in the chest wall must be known to accurately measure Pu in the human lung. Correction factors of 100% or more in x-ray detection efficiency are common. Methods using simple /sup 40/K and biometric measurement techniques were investigated to determine the adipose content in the human chest wall. These methods predict adipose content to within 15% of the absolute ultrasonic value. These new methods are discussed and compared with conventional ultrasonic measurement techniques. (ERB)
Date: January 22, 1982
Creator: Anderson, A. L. & Campbell, G. W.
System: The UNT Digital Library
Inertial-confinement-fusion applications of ion-stopping theory (open access)

Inertial-confinement-fusion applications of ion-stopping theory

Methods were developed to calculate: (1) the stopping power of a hot plasma target, (2) the charge-state of a fast ion projectile, and (3) the final disposition of the deposited energy. The first issue refers to the stopping power for protons. The proton stopping power is altered in high-density or high-temperature targets, especially at velocities below the stopping peak. The second issue concerns the application of a proton stopping curve to the arbitrary projectile. The third topic is more specialized to inertial fusion and concerns the partition of deposited energy between ion (nuclear motion) degrees of freedom and those corresponding to bound and free electrons. The question here is whether a thermal equilibrium plasma is produced.
Date: January 22, 1982
Creator: More, Richard M.; Lee, Yim T. & Bailey, David S.
System: The UNT Digital Library
Study of proton-induced reactions and correlation with fast-neutron scattering (open access)

Study of proton-induced reactions and correlation with fast-neutron scattering

The generation of cross sections for fast neutron-nucleon interactions obtained from elastic and charge-exchange proton data is discussed in terms of the Lane model formalism. A general description of the interaction of nucleons with nuclei is presented in terms of the optical model and the extended (or coupled-channel) optical model, together with the relation of these models to microscopic calculations of the nucleon-nucleon interaction. Comparisons between neutron elastic data and calculations carried out with optical model potentials obtained from (p,p) and (p,n) data are presented for a large number of nuclei. The validity of the Lane model and the importance of coupled effects in the actinide region are shown in a detailed comparison of calculations for elastic and inelastic neutron differential cross sections and measurements for /sup 232/Th and /sup 238/U.
Date: January 19, 1982
Creator: Hansen, L. F.
System: The UNT Digital Library
Review of the beta situation (open access)

Review of the beta situation

This note lists some of the possible causes of beta limitation in tokamak and discusses what is known and what is involved in investigating them. The motivation for preparing this note is the observed degradation of confinement with increasing beta poloidal ..beta../sub p/ and beam power P/sub b/ in ISX-B.
Date: January 18, 1982
Creator: Sheffield, J.
System: The UNT Digital Library
Halide laser glasses (open access)

Halide laser glasses

Energy storage and energy extraction are of prime importance for efficient laser action and are affected by the line strengths and linewidths of optical transitions, excited-state lifetimes, nonradiative decay processes, spectroscopic inhomogeneities, nonlinear refractive index, and damage threshold. These properties are all host dependent. To illustrate this, the spectroscopic properties of Nd/sup 3 +/ have been measured in numerous oxide, oxyhalide, and halide glasses. A table summarizes the reported ranges of stimulated emission cross sections, peak wavelengths, linewidths, and radiative lifetimes associated with the /sup 4/F/sub 3/2/ ..-->.. /sup 4/I/sub 11/2/ lasing transition.
Date: January 14, 1982
Creator: Weber, M. J.
System: The UNT Digital Library
SEBREZ: an inertial-fusion-reactor concept (open access)

SEBREZ: an inertial-fusion-reactor concept

The neutronic aspects of an inertial fusion reactor concept that relies on asymmetrical neutronic effects to enhance the tritium production in the breeding zones have been studied. We find that it is possible to obtain a tritium breeding ratio greater than 1.0 with a chamber configuration in which the breeding zones subtend only a fraction of the total solid angle. This is the origin of the name SEBREZ which stands for SEgregated BREeding Zones. It should be emphasized that this is not a reactor design study; rather this study illustrates certain neutronic effects in the context of a particular reactor concept. An understanding of these effects forms the basis of a design technique which has broader application than just the SEBREZ concept.
Date: January 13, 1982
Creator: Meier, W. R.
System: The UNT Digital Library
Chemical-kinetic prediction of critical parameters in gaseous detonations (open access)

Chemical-kinetic prediction of critical parameters in gaseous detonations

A theoretical model including a detailed chemical kinetic reaction mechanism for hydrogen and hydrocarbon oxidation is used to examine the effects of variations in initial pressure and temperature on the detonation properties of gaseous fuel-oxidizer mixtures. Fuels considered include hydrogen, methane, ethane, ethylene, and acetylene. Induction lengths are computed for initial pressures between 0.1 and 10.0 atmospheres and initial temperatures between 200K and 500K. These induction lengths are then compared with available experimental data for critical energy and critical tube diameter for initiation of spherical detonation, as well as detonation limits in linear tubes. Combined with earlier studies concerning variations in fuel-oxidizer equivalence ratio and degree of dilution with N/sub 2/, the model provides a unified treatment of fuel oxidation kinetics in detonations. 4 figures, 1 table.
Date: January 12, 1982
Creator: Westbrook, C.K. & Urtiew, P.A.
System: The UNT Digital Library
A 0. 4 mm Interferometer System Using Dielectric Waveguide (open access)

A 0. 4 mm Interferometer System Using Dielectric Waveguide

A 0.4 mm submillimeter-wave, phase-modulated polarimeter/interferometer is used for simultaneous time-dependent measurement of line-averaged electron density and poloidal field-induced Faraday rotation along chords of the plasma column in ISX-B tokamak. Heterodyna detection and hollow dielectric waveguide are utilized to achieve the high sensitivity required for the multichord equipment.
Date: January 1, 1982
Creator: Hutchinson, D. P.; Ma, C. H.; Staats, P. A. & Vander Sluis, K. L.
System: The UNT Digital Library
0/sup -/ to 0/sup +/ beta decay in A = 16 (open access)

0/sup -/ to 0/sup +/ beta decay in A = 16

Techniques and results of the measurement of the beta-decay rate of the first excited state of /sup 16/N to the ground state of /sup 16/O are reported. Energy levels involved in the decay are shown, and the /sup 16/N 0/sup -/ beta decay branching ration is given. (WHK)
Date: January 1, 1982
Creator: Gagliardi, C.; Garvey, G. T.; Wrobel, J. R. & Freedman, S. J.
System: The UNT Digital Library
1-D hybrid code for FRM start-up (open access)

1-D hybrid code for FRM start-up

A one-D hybrid has been developed to study the start-up of the FRM via neutral-beam injection. The code uses a multi-group numerical model originally developed by J. Willenberg to describe fusion product dynamics in a solenoidal plasma. Earlier we described such a model for use in determining self-consistent ion currents and magnetic fields in FRM start-up. However, consideration of electron dynamics during start-up indicate that the electron current will oppose the injected ion current and may even foil the attempt to achieve reversal. For this reason, we have combined the multi-group ion (model) with a fluid treatment for electron dynamics to form the hybrid code FROST (Field Reversed One-dimensional STart-up). The details of this merger, along with sample results of operation of FROST, are given.
Date: January 1, 1982
Creator: Stark, R. A. & Miley, G. H.
System: The UNT Digital Library
2. 6/sup 0/K refrigeration system for CBA magnet testing (open access)

2. 6/sup 0/K refrigeration system for CBA magnet testing

The superconducting magnets for the accelerator's rings will be cooled by a forced flow supercritical helium system from a central refrigeration plant. The design temperature for these magnets varies from 2.6 to 3.8/sup 0/K depending on a magnet's location in the ring. This paper describes the forced flow cooling system for testing a prototype magnet near 2.6/sup 0/K; this lowest temperature being of special interest to evaluate magnet quench protection. The test forced flow cooling system uses a three-stage approach, including an ejector pumped bath, similar to a cycle described previously. The coolant exists at 3.8/sup 0/K from these first stages and is then cooled further in a 64 cm diameter by 3 m high shielded liquid helium dewar. The supercritical helium gas passes through a submerged copper coil in this bath which is pumped to a pressure of 65 mm absolute by a screw compressor system. Temperatures are measured by thermistors located in the gas stream, and also embedded in the magnet coil.
Date: January 1, 1982
Creator: Bamberger, Joseph A.
System: The UNT Digital Library
2-D Eulerian hydrodynamics with fluid interfaces, self-gravity and rotation (open access)

2-D Eulerian hydrodynamics with fluid interfaces, self-gravity and rotation

The purpose of this paper is to describe in detail the numerical approach we have developed over the past five years for solving 2-dimensional gas-dynamical problems in astrophysics involving inviscid compressible flow, self-gravitation, rotation, and fluid instabilities of the Rayleigh-Taylor and Kelvin-Helmholtz types. The computer code to be described has been applied most recently to modeling jets in radio galaxies (Norman et al. 1981, 1982) and is an outgrowth of a code developed for studying rotating protostellar collapse (Norman, Wilson and Barton 1980; Norman 1980). This basic methodology draws heavily on the techniques and experience of James R. Wilson and James M. LeBlanc of the Lawrence Livermore National Laboratory, and thus the code is designed to be a general purpose 2-D Eulerian hydrocode, and is characterized by a high degree of simplicity, robustness, modularity and speed. Particular emphases of this article are: (1) the recent improvements to the code's accuracy through the use of vanLeer's (1977) monotonic advection algorithm, (2) a discussion of the importance of what we term consistent advection, and (3) a description of a numerical techique for modeling dynamic fluid interfaces in multidimensional Eulerian calculations developed by LeBlanc. 23 refs., 14 figs.
Date: January 1, 1982
Creator: Norman, M.L. & Winkler, K.H.A.
System: The UNT Digital Library
S = -2 dibaryons and hypernuclei (open access)

S = -2 dibaryons and hypernuclei

Future prospects for the exploration of doubly strange hypernuclear systems are evaluated. Such systems may be produced via the double strangeness exchange reactions (K/sup -/,K/sup +/) or (K/sup -/,K/sup 0/) on nuclear targets. Theoretical estimates are given of the formation cross sections for Xi/sup -/ hypernuclear states via the one-step K/sup -/p ..-->.. K/sup +/Xi/sup -/ process, or discrete states of the ..lambda lambda.. hypernucleus in the two step reaction K/sup -/p ..-->.. ..pi../sup 0/..lambda.. followed by ..pi../sup 0/p ..-->.. K/sup +/..lambda... Recently, there has been much discussion of six quark (dibaryon) states in the Bag Model. Arguments are given which indicate that the (K/sup -/,K/sup +/) reaction on light nuclear targets (ex. /sup 3/He) affords a very promising way of producing the lowest-lying S = -2 dibaryon (called the H).
Date: January 1, 1982
Creator: Dover, C.B.
System: The UNT Digital Library
3-D solution of flow in an infinite square array of circular tubes by using boundary-fitted coordinate system (open access)

3-D solution of flow in an infinite square array of circular tubes by using boundary-fitted coordinate system

Heat transfer and fluid flow over circular tubes have wide applications in the design of heat exchangers and nuclear reactors. However, it is often difficult to accurately calculate the detailed velocity and temperature distributions of the flow because of the complex geometry involved in the analysis, and a lack of an appropriate coordinate system for the analysis. Boundary conditions on the surfaces of the tubes are often interpolated. This interpolation process introduces inaccuracy. To overcome this difficulty, the present study used the technique of the boundary-fitted coordinate system. In this technique, all the physical boundaries are transformed into constant coordinate lines in the transformed coordinates. Therefore, the boundary conditions can be specified on the grid points without interpolation.
Date: January 1, 1982
Creator: Chen, B. C. J.; Chien, T. H.; Sha, W. T. & Kim, J. H.
System: The UNT Digital Library
A = 4 0/sup +/ - 1/sup +/ binding-energy difference (open access)

A = 4 0/sup +/ - 1/sup +/ binding-energy difference

The A = 4 ..lambda..-hypernuclei provide a rich source of information about the s-wave properties of the fundamental hyperon-nucleon (YN) force as well as offer a unique opportunity to investigate the complications that arise in calculations of the properties of bound systems in which one baryon (here the ..lambda..) with a given isospin couples strongly to another (the ..sigma..) with a different isospin. The ..lambda../sup 4/H - ..lambda../sup 4/He isodoublet ground-state energies are not consistent with a charge symmetry hypothesis for the YN interaction. The (spin-flip) excitation energies are quite sensitive to the ..lambda..N - ..sigma..N coupling of the YN interaction. In particular, when one represents the free YN interaction in terms of one-channel effective ..lambda..N potentials, the resulting 0/sup +/ (ground) state and 1/sup +/ (excited) spin-flip state are inversely ordered in terms of binding energies, the 1/sup +/ state being more bound. It is the ..sigma.. suppression that results from the reduced strength of the ..lambda..N - ..sigma..N off-diagonal coupling potential when the trinucleon core is restricted to isospin-1/2 which we study here. We find this spin-isospin suppression of the ..lambda..-..sigma.. conversion, which is due to the composite nature of the nuclear cores of the ..lambda../sup 4/H and …
Date: January 1, 1982
Creator: Gibson, B. F. & Lehman, D. R.
System: The UNT Digital Library
1982 engineering conference on reliability for the electrical power industry (open access)

1982 engineering conference on reliability for the electrical power industry

Emergency onsite ac power systems at nuclear power plants are a major concern in plant risk assessments because of the relatively large frequency of loss of offsite power and the dependence of most other safety systems on ac power. Detailed reviews of onsite ac power system designs and reviews of experience with diesel generators at US nuclear power plants form the basis of system reliability analyses that show significant improvements in reliability can be obtained at moderate cost for some plants. Onsite ac power system modifications analyzed include procedural modifications, minor equipment modifications and major equipment additions. Relative costs of various modifications are compared with associated system reliability improvements.
Date: January 1, 1982
Creator: Campbell, D. J.; Arendt, J. S.; Battle, R. E. & Baranowsky, P. W.
System: The UNT Digital Library
1D thermonuclear model for x-ray transients (open access)

1D thermonuclear model for x-ray transients

The thermonuclear evolution of a 1.41 M solar mass neutron star, with a radius of 14.3 km, accreting various mixtures of hydrogen, helium, and heavy elements at rates of 10/sup -11/ to 10/sup -10/ M solar mass/yr is examined, in conjunction with S.E. Woosley and T.A. Weaver, using a one-dimensional numerical model. We have ignored any effects due to general relativity or magnetic fields. Two cases shall be discussed. In both models, the accretion rate is such that the hydrogen shell burns to helium in steady state, with the hydrogen burning stabilized by the ..beta..-limited CNO cycle. A thick helium shell is produced, which is eventually ignited under extremely degenerate conditions, producing a thermonuclear runaway.
Date: January 1, 1982
Creator: Wallace, R. K.
System: The UNT Digital Library
Absolutely calibrated soft-x-ray streak camera for laser-fusion applications (open access)

Absolutely calibrated soft-x-ray streak camera for laser-fusion applications

The intensity output of a soft-x-ray streak camera was calibrated (SXRSC) in order to make absolute flux measurements of x rays emitted from laser-produced plasmas. The SXRSC developed at LLNL is used to time-resolve x-ray pulses to better than 20 ps. The SXRSC uses a Au photocathode on a thin carbon substrate which is sensitive to x rays from 100 eV to greater than 10 keV. Calibrations are done in the dynamic mode using a small laser-produced x-ray source. The SXRSC is calibrated by comparing its integrated signal to the output of calibrated x-ray diodes monitoring the source strength. The measured SXRSC response is linear over greater than two orders of magnitude. Using these calibrations, absolute intensities can be measured to an accuracy of +-30%.
Date: January 1, 1982
Creator: Kauffman, R.L.; Medecki, H. & Stradling, G.
System: The UNT Digital Library
Acceleration of heavy ions to very high energies (open access)

Acceleration of heavy ions to very high energies

The current interest of physicists in the collisions of heavy ions closes an interesting circle in the technology of accelerator building. The first cyclic accelerator, built by R. Wideroe, was a linear accelerator designed to accelerate potassium ions. Subsequent to Wideroe's achievement, much of the art of accelerator construction has been devoted to creating energetic beams of electrons and protons. Now we find ourselves returning to the heavy ions, and Wideroe's linear accelerator structure still plays an important role in many acceleration schemes. Fortunately, while the particle physics community has concentrated on the electron and proton machines, the nuclear physicists have kept alive the interest in heavy ions. Now a host of electrostatic machines, cyclotrons, and heavy ion linear accelerators provide beams of all species of ions at energies from about 100 MeV per nucleon for light isotopes to 10 MeV per nucleon for the heaviest isotopes in support of vigorous physics programs.
Date: January 1, 1982
Creator: Barton, M. Q.
System: The UNT Digital Library
Accident analysis and DOE criteria (open access)

Accident analysis and DOE criteria

In analyzing the radiological consequences of major accidents at DOE facilities one finds that many facilities fall so far below the limits of DOE Order 6430 that compliance is easily demonstrated by simple analysis. For those cases where the amount of radioactive material and the dispersive energy available are enough for accident consequences to approach the limits, the models and assumptions used become critical. In some cases the models themselves are the difference between meeting the criteria or not meeting them. Further, in one case, we found that not only did the selection of models determine compliance but the selection of applicable criteria from different chapters of Order 6430 also made the difference. DOE has recognized the problem of different criteria in different chapters applying to one facility, and has proceeded to make changes for the sake of consistency. We have proposed to outline the specific steps needed in an accident analysis and suggest appropriate models, parameters, and assumptions. As a result we feed DOE siting and design criteria will be more fairly and consistently applied.
Date: January 1, 1982
Creator: Graf, Joseph M. & Elder, John C.
System: The UNT Digital Library
Acoustic disturbance at ionospheric heights caused by the MILL RACE explosion (open access)

Acoustic disturbance at ionospheric heights caused by the MILL RACE explosion

The principal objective of the Los Alamos National Laboratory in the MILL RACE experiment was to measure the over-head ionospheric response due to the MILL RACE explosion. Such a measurement enables one to test computer models designed to quantitatively predict ionospheric disturbances caused by known sources. The emphasis of the models has been directed at calculating effects on rf propagation associated with the predicted ionospheric disturbances. Consequently vertical incidence phase sounding measurements of a well-characterized source provide a direct and sensitive test of the computer models and, for this reason, a vertical incidence phase sounder was located 3300 meters to the west of the MILL RACE ground zero. Another area of interest is the development of an understanding of the atmospheric response to known sources at distances where the acoustic response no longer dominates. Such an undertaking requires measurements at these remote points. Deployment of a bistatic sounding network enabled the investigation of this area of interest. Results are reported.
Date: January 1, 1982
Creator: Rickel, D.G. & Simons, D.J.
System: The UNT Digital Library