Grand unified theories (open access)

Grand unified theories

Topics discussed include coupling constants; minimal SU(5) predictions (sin/sup 2/theta/sub W/, m/sub W/ and m/sub Z/, proton decay, and magnetic monopoles); Higgs scalar effects including proton decay and flavor changing and oscillation phenomena; and supersymmetry. 31 references.
Date: September 11, 1983
Creator: Marciano, W. J.
System: The UNT Digital Library
Cosmological and astrophysical implications of magnetic monopoles (open access)

Cosmological and astrophysical implications of magnetic monopoles

Among Dirac's many contributions to modern physics is the idea that charge quantization is natural in a theory with magnetic monopoles. The existence of magnetic monopoles would have drastic effects on the evolution of the universe, on galactic magnetic fields, and perhaps on the x-ray luminosity of neutron stars. Some astrophysical implications of massive magnetic monopoles are reviewed here.
Date: March 11, 1983
Creator: Kolb, E.W.
System: The UNT Digital Library
Radial mode structure of curvature-driven instabilities in EBT (open access)

Radial mode structure of curvature-driven instabilities in EBT

Viewgraphs describe the theoretical treatment of the radial mode structure of plasma instabilities in the Elmo Bumpy Torus. The calculation retains nonlocal structure of the modes, connects inner and outer ring regions together, uses a self-consistent finite ..beta.., includes the relativistic effects for the hot electron ring, and examines a wide range of parameters. (WRF)
Date: January 11, 1983
Creator: Spong, D. A.
System: The UNT Digital Library
Fokker-Planck equation in mirror research (open access)

Fokker-Planck equation in mirror research

Open confinement systems based on the magnetic mirror principle depend on the maintenance of particle distributions that may deviate substantially from Maxwellian distributions. Mirror research has therefore from the beginning relied on theoretical predictions of non-equilibrium rate processes obtained from solutions to the Fokker-Planck equation. The F-P equation plays three roles: Design of experiments, creation of classical standards against which to compare experiment, and predictions concerning mirror based fusion power systems. Analytical and computational approaches to solving the F-P equation for mirror systems will be reviewed, together with results and examples that apply to specific mirror systems, such as the tandem mirror.
Date: August 11, 1983
Creator: Post, Richard F.
System: The UNT Digital Library
Cytometry of mammalian sperm (open access)

Cytometry of mammalian sperm

Male germ cells respond dramatically to a variety of insults and are important reproductive dosimeters. Semen analyses are very useful in studies on the effects of drugs, chemicals, and environmental hazards on testicular function, male fertility and heritable germinal mutations. The accessibility of male cells makes them well suited for analytical cytology. We might automate the process of determining sperm morphology but should not do so solely for increased speed. Rather, richer tangible benefits will derive from cytometric evaluation through increased sensitivity, reduced subjectivity, standardization between investigators and laboratories, enhanced archival systems, and the benefits of easily exchanged standardized data. Inroads on the standardization of assays for motility and functional integrity are being made. Flow cytometric analysis of total DNA content of individual sperm is an insensitive means to detect exposure to reproductive toxins because of the small size and low frequency of the DNA content errors. Flow cytometry can be applied to determine the proportions of X- and Y-sperm in semen samples.
Date: October 11, 1983
Creator: Gledhill, B.L.
System: The UNT Digital Library
Magnetic-mirror principle as applied to fusion research (open access)

Magnetic-mirror principle as applied to fusion research

A tutorial account is given of the key physics issues in the confinement of high temperature plasma in magnetic mirror systems. The role of adiabatic invariants and particle drifts and their relationship to equilibrium and stability are discussed, in the context of the various forms of mirror field geometry. Collisional effects and the development and the control of ambipolar potentials are reviewed. The topic of microinstabilities is discussed together with the means for their control. The properties and advantages for fusion power purposes of various special embodiments of the mirror idea, including tandem mirrors, are discussed.
Date: August 11, 1983
Creator: Post, Richard F.
System: The UNT Digital Library
Effect of Heat Treatment on the Impact Properties of a 12Cr-1Mo-V-W Steel (open access)

Effect of Heat Treatment on the Impact Properties of a 12Cr-1Mo-V-W Steel

This paper describes the effects of austenitization and tempering treatments on the strength and impact properties of a 12Cr-1Mo-V-W steel. Data are reported for austenitization temperatures covering the range 900 to 1250/sup 0/C and tempering treatments of 600 to 800/sup 0/C. A 50/sup 0/C improvement in the ductile brittle transition temperature is achieved through heat treatment. This is found to result from elimination of delta ferrite and associated carbides at the delta ferrite-matrix interface. 17 figures.
Date: November 11, 1983
Creator: Chin, B. A. & Wilcox, R. C.
System: The UNT Digital Library
Generation of vibrationally excited H/sub 2/ molecules by H/sub 2//sup +/ wall collisions (open access)

Generation of vibrationally excited H/sub 2/ molecules by H/sub 2//sup +/ wall collisions

The H/sub 2//sup +/ ions from the volume of a hydrogen discharge will strike the discharge chamber walls with a kinetic energy equivalent to the plasma potential. A three-step process is described in which the H/sub 2//sup +/ ions are neutralized in a two-stage Auger process followed by a third stage wall relaxation collision, with the net result that the incident ions are converted to ground state molecules having a broad vibrational excitation spectrum. For kinetic energies ranging from a few electron volts up to twenty electron volts a substantial fraction, approx. = 2/3, of these ions will reflect as molecules, and of this population a fraction as large as twenty percent will have vibrational excitation of v'' greater than or equal to 6. This large vibrational population will provide a contribution to the total excited level distribution that is comparable to the E-V process. Implications for negative ion generation in an optimized tandem configuration are discussed.
Date: November 11, 1983
Creator: Hiskes, J.R. & Karo, A.M.
System: The UNT Digital Library
Volume generation of negative ions in high density hydrogen discharges. Revision 1 (open access)

Volume generation of negative ions in high density hydrogen discharges. Revision 1

An optimized tandem two-chamber negative-ion source system is discussed. In the first chamber high energy (E > 20 eV) electron collisions provide for H/sub 2/ vibrational excitation, while in the second chamber negative ions are formed by dissociative attachment. The gas density, electron density, and system scale length are varied as independent parameters. The extracted negative ion current density passes through a maximum as electron and gas densities are varied. This maximum scales inversely with system scale length, R. The optimum extracted current densities occur for electron densities near nR = 10/sup 13/ electrons cm/sup -2/ and for gas densities, N/sub 2/R, in the range 10/sup 14/ to 10/sup 15/ molecules cm/sup -2/. The extracted current densities are sensitive to the atomic concentration in the discharge. The atomic concentration is parametrized by the wall recombination coefficient, ..gamma.., and scale length, R. As ..gamma.. ranges from 0.1 to 1.0 and for system scale lengths of one centimeter, extracted current densities range from 8.0 to 80. mA cm/sup -2/.
Date: November 11, 1983
Creator: Hiskes, J.R. & Karo, A.M.
System: The UNT Digital Library
Dipole aperture and superconductor requirements (open access)

Dipole aperture and superconductor requirements

The cost of an accelerator is not proportional to the aperture. A change in aperture by a certain percentage results in an overall accelerator cost change by only a fraction of that percentage; the fraction may be between 0.1 and 0.5 and is almost independent of the bending field. This estimate is obtained by analyzing the superconductor requirements as a function of aperture and by making rough estimates of the largest cost items of the accelerator such as magnets and ring tunnel.
Date: December 11, 1983
Creator: Wipf, S.L.
System: The UNT Digital Library
Insulator materials in high power lasers for inertial fusion: present and future (open access)

Insulator materials in high power lasers for inertial fusion: present and future

A summary is given of the important characteristics of currently used insulator materials. Figures of merit for materials needed in future systems are identified. A methodology for identifying and evaluating new materials meeting the stringent performance requirements of future fusion laser systems is outlined.
Date: November 11, 1983
Creator: Krupke, W. F.
System: The UNT Digital Library
Energy-beam processing studies on Ta/U and Ir/Ta systems. [Laser-and electron-beam melting] (open access)

Energy-beam processing studies on Ta/U and Ir/Ta systems. [Laser-and electron-beam melting]

Films of Ta metal on uranium and of Ir metal on tantalum have been irradiated and melted by pulses from Q-switched Ruby and frequency-doubled Nd:YAG lasers to investigate the nature of the resulting mixtures in light of the very different binary-phase diagrams of the two systems. In addition, a two-phase Ir-Ta alloy has been surface-processed with CW CO/sub 2/-laser radiation and with an electron beam in order to study microstructure refinement and test the advantage of using alloys as opposed to film-on-substrate combinations for the development of claddings.
Date: November 11, 1983
Creator: Kaufmann, E. N.; Peercy, P. S.; Jacobson, D. C.; Draper, C. W.; Huegel, F. J.; Echer, C. J. et al.
System: The UNT Digital Library