Application of the results of excavation response experiments at climax and the Colorado School of Mines to the development of an experiment for the underground research laboratory (open access)

Application of the results of excavation response experiments at climax and the Colorado School of Mines to the development of an experiment for the underground research laboratory

Large-scale underground experiment programs to examine excavation response have been performed at the Climax facility in Nevada and at the Colorado School of Mines. These two programs provided fundamental information on the behavior of rock and the effects of excavation; on instrument performance and configuration; and on the relationship between test geometry and test behavior. This information is being considered in the development of a major excavation response experiment to be carried out in the Canadian Underground Research Laboratory. 11 refs., 3 figs.
Date: April 29, 1988
Creator: Ubbes, W. F.; Yow, J. L., Jr. & Hustrulid, W. A.
System: The UNT Digital Library
Why search for double beta decay (open access)

Why search for double beta decay

Searching for neutrinoless double beta decay is the only known practical method for trying to determine whether neutrinos are their own antiparticles. The theoretical motivation for supposing that they may indeed be their own antiparticles is described. The reason that it is so difficult to ascertain experimentally whether they are or are not is explained, as is the special sensitivity of neutrinoless double beta decay. The potential implications of the observation of this reaction for neutrino mass and for the physics of neutrinos is discussed.
Date: April 20, 1988
Creator: Kayser, B.
System: The UNT Digital Library
In-beam studies of sup 96 Zr and sup 98 Zr: Collective excitations (open access)

In-beam studies of sup 96 Zr and sup 98 Zr: Collective excitations

Nearly two decades ago signatures of deformation in the ground state bands of {sup 100}Zr and {sup 102}Zr were identified, and the rapid change in the deformation of heavy zirconium nuclei noted. It is now well accepted that the short-range proton-neutron interaction between the 1g{sub 9/2} and 1g{sub 7/2} spin-orbit partners plays an important role in producing ground state deformation in this region. Nevertheless, recent studies of zirconium nuclei, including those in the transition region, continue to refine our understanding of the interplay between single-particle and collective degrees of freedom. In this report we discuss some aspects of the level structures of {sup 96}Zr and {sup 98}Zr with emphasis on collective excitations. 18 refs., 2 tabs.
Date: April 18, 1988
Creator: Henry, E. A.; Meyer, R. A.; Aprahamian, A.; Mann, L. G.; Roy, N. (Lawrence Livermore National Lab., CA (USA)) & Maier, K. H. (Hahn-Meitner-Institut fuer Kernforschung Berlin G.m.b.H. (Germany, F. R.))
System: The UNT Digital Library
The classical nova outburst. [None] (open access)

The classical nova outburst. [None]

The classical nova outburst occurs on the white dwarf component in a close binary system. Nova systems are members of the general class of cataclysmic variables and other members of the class are the Dwarf Novae, AM Her variables, Intermediate Polars, Recurrent Novae, and some of the Symbiotic variables. Although multiwavelength observations have already provided important information about all of these systems, in this review I will concentrate on the outbursts of the classical and recurrent novae and refer to other members of the class only when necessary. 140 refs., 1 tab.
Date: April 11, 1988
Creator: Starrfield, S. G.
System: The UNT Digital Library
Present capabilities and new developments in antenna modeling with the numerical electromagnetics code NEC (open access)

Present capabilities and new developments in antenna modeling with the numerical electromagnetics code NEC

Computer modeling of antennas, since its start in the late 1960's, has become a powerful and widely used tool for antenna design. Computer codes have been developed based on the Method-of-Moments, Geometrical Theory of Diffraction, or integration of Maxwell's equations. Of such tools, the Numerical Electromagnetics Code-Method of Moments (NEC) has become one of the most widely used codes for modeling resonant sized antennas. There are several reasons for this including the systematic updating and extension of its capabilities, extensive user-oriented documentation and accessibility of its developers for user assistance. The result is that there are estimated to be several hundred users of various versions of NEC world wide. 23 refs., 10 figs.
Date: April 8, 1988
Creator: Burke, G. J.
System: The UNT Digital Library
Preparing the database for future CP violation measurements with B-mesons at e/sup +/e/sup -/ machines (open access)

Preparing the database for future CP violation measurements with B-mesons at e/sup +/e/sup -/ machines

We consider the contribution of e/sup /plus//e/sup /minus// machines to the measurement of CP violation in the B systems. Energy regions from the GAMMA(4S) to the Z/degree/ are considered, problems and prospects at each energy are reviewed.
Date: April 7, 1988
Creator: Byers, N.; Foley, K.; Goldberg, M.; Mistry, N & Shipsey, I.
System: The UNT Digital Library
A turning point in the US Inertial Confinement Fusion Program (open access)

A turning point in the US Inertial Confinement Fusion Program

The goal of the US ICF Program is to obtain a high-yield (100 to 1000 MJ) and high-gain (about 100) thermonuclear fusion capability in the laboratory. It has long been recognized that before such a laboratory facility is constructed, it must be demonstrated that laboratory conditions can be created that will, with high probability, lead to high gain if a driver of sufficient energy is built and that such a facility can be built at reasonable cost. Thus, the two major aspects of the US program address target physics and driver development. Four main driver candidates are actively being pursued: solid state lasers (principally Nd:glass), KrF gas lasers, light ion beams (Li ions accelerated by ion diodes), and heavy ion beams )A /approximately/200, accelerated by linear induction accelerator). The target physics aspect of the program is further divided into indirect and direct drive targets. In indirect drive targets the driver beams are aimed at a material near the capsule to generate x-rays, which then are absorbed in the fusion capsule ablator to produce the implosion. In direct-drive targets, the driver beams are aimed at the surface of the capsule. However, even in this case it should be recognized that the …
Date: April 7, 1988
Creator: Hogan, W.J.
System: The UNT Digital Library
Beryllium usage in fusion blankets and beryllium data needs. [None] (open access)

Beryllium usage in fusion blankets and beryllium data needs. [None]

Increasing numbers of designers are choosing beryllium for fusion reactor blankets because it, among all nonfissile materials, produces the highest number (2.5 neutron in an infinite media) of neutrons per 14-MeV incident neutron. In amounts of about 20 cm of equivalent solid density, it can be used to produce fissile material, to breed all the tritium consumed in ITER from outboard blankets only, and in designs to produce Co-60. The problem is that predictions of neutron multiplication in beryllium are off by some 10 to 20% and appear to be on the high side, which means that better multiplication measurements and numerical methods are needed. The n,2n reactions result in two helium atoms, which cause radiation damage in the form of hardening at low temperatures (<300/degree/C) and swelling at high temperatures (>300/degree/C). The usual way beryllium parts are made is by hot pressing the powder. A lower cost method is to cold press and then sinter. There is no radiation damage data on this form of beryllium. The issues of corrosion, safety relative to the release of the tritium built-up inside beryllium, and recycle of used beryllium are also discussed. 10 figs.
Date: April 6, 1988
Creator: Moir, Ralph W.
System: The UNT Digital Library
TIBER (Tokamak Ignition/Burn Experimental Reactor) II as a precursor to an international thermonuclear experimental reactor (open access)

TIBER (Tokamak Ignition/Burn Experimental Reactor) II as a precursor to an international thermonuclear experimental reactor

The Tokamak Ignition/Burn Experimental Reactor (TIBER) was pursued in the US as one option for an International Thermonuclear Experimental Reactor (ITER). This concept evolved from earlier work on the Tokamak Fusion Core Experiment (TFCX) to develop a small, ignited tokamak. While the copper-coil versions of TFCX became the short-pulsed, 1.23-m radius, Compact Ignition Tokamak (CIT), the superconducting TIBER with long pulse or steady state and a 2.6-m radius was considered for international collaboration. Recently the design was updated to TIBER II, to accommodate more conservative confinement scaling, double-poloidal divertors for impurity control, steady-state current drive, and nuclear testing. 18 refs., 1 fig.
Date: April 6, 1988
Creator: Henning, C. D. & Gilleland, J. R.
System: The UNT Digital Library
Analytical methods for large-scale sensitivity analysis using GRESS (GRadient Enhanced Software System) and ADGEN (Automated Adjoint Generator) (open access)

Analytical methods for large-scale sensitivity analysis using GRESS (GRadient Enhanced Software System) and ADGEN (Automated Adjoint Generator)

Sensitivity analysis is an established methodology used by researchers in almost every field to gain essential insight in design and modeling studies and in performance assessments of complex systems. Conventional sensitivity analysis methodologies, however, have not enjoyed the widespread use they deserve considering the wealth of information they can provide, partly because of their prohibitive cost or the large initial analytical investment they require. Automated systems have recently been developed at ORNL to eliminate these drawbacks. Compilers such as GRESS and ADGEN now allow automatic and cost effective calculation of sensitivities in FORTRAN computer codes. In this paper, these and other related tools are described and their impact and applicability in the general areas of modeling, performance assessment and decision making for radioactive waste isolation problems are discussed. 7 refs., 2 figs.
Date: April 1, 1988
Creator: Pin, F.G.
System: The UNT Digital Library
Application of controlled interfacial pore structures to kinetic studies in alumina (open access)

Application of controlled interfacial pore structures to kinetic studies in alumina

The application of controlled-geometry interfacial pore structures to fundamental kinetic studies in alumina is described. Results from studies of the morphological stability of high aspect ratio pore channels, crack healing, pore coarsening and pore elimination in sapphire are presented.
Date: April 1, 1988
Creator: Roedel, J. & Glaeser, A.M.
System: The UNT Digital Library
B-factories (open access)

B-factories

We briefly review the physics of CP violation and the interest of studying this phenomenon in the B-meson system. The need for very large numbers of B-decays is shown, and a number of approaches for B-factories are compared. In particular, e/sup +/e/sup /minus// linear and circular colliders are discussed in some detail, with specific examples presented. 31 refs., 22 figs., 5 tabs.
Date: April 1, 1988
Creator: Bloom, E. D.
System: The UNT Digital Library
Can neutrino-electron scattering tell us whether neutrinos are Dirac or Majorana particles (open access)

Can neutrino-electron scattering tell us whether neutrinos are Dirac or Majorana particles

There has recently been interest in the possibility that neutrino-electron scattering experiments could determine whether neutrinos are Dirac or Majorana particles by providing information on their electromagnetic structure. We try to explain why studies of neutrino electromagnetic structure actually cannot distinguish between Dirac and Majorana neutrinos. 9 refs.
Date: April 1, 1988
Creator: Kayser, B.
System: The UNT Digital Library
Characteristics of spent nuclear fuel (open access)

Characteristics of spent nuclear fuel

The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will, or may, eventually be disposed of in a geological repository. The two major sources of these materials are commercial light-water reactor (LWR) spent fuel and immobilized high-level waste (HLW). Other wastes that may require long-term isolation include non-LWR spent fuels and miscellaneous sources such as activated metals. This report deals with spent fuels, but for completeness, the other sources are described briefly. Detailed characterizations are required for all of these potential repository wastes. These characteristics include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. In addition, the present inventories and projected quantities of the various wastes are needed. This information has been assembled in a Characteristics Data Base which provides data in four formats: hard copy standard reports, menu-driven personal computer (PC) data bases, program-level PC data bases, and mainframe computer files. 5 refs., 3 figs., 4 tabs.
Date: April 1, 1988
Creator: Notz, K.J.
System: The UNT Digital Library
Chinese strategic weapons and the plutonium option (U) (open access)

Chinese strategic weapons and the plutonium option (U)

In their article &quot;Chinese Strategic Weapons and the Plutonium Option,&quot; John W. Lewis and Xue Litai of the Center for International Security and Arms Control at Stanford University&#x27;s International Strategic Institute present an unclassified look at plutonium processing in the PRC. The article draws heavily on unclassified PRC sources for its short look at this important subject. Interested readers will find more detailed information in the recently available works referenced in the article.
Date: April 1, 1988
Creator: Lewis, John W. & Litai, Xui
System: The UNT Digital Library
Comparison of premortem and postmortem estimates of plutonium deposited in the skeleton and liver of six individuals (open access)

Comparison of premortem and postmortem estimates of plutonium deposited in the skeleton and liver of six individuals

Assessment of organ burdens after internal exposures to radionuclides is often necessary to evaluate the health and regulatory implications of the exposure. The assessment of plutonium activity in skeleton and liver is usually estimated from measurements of plutonium excreted via urine. As part of the overall evaluation of internal dose assessment techniques, it is useful to compare the results of organ burden estimates made from evaluation of urinary excretion data with those made at death from tissue samples collected posthumously from the individual. Estimates of plutonium in the skeleton and liver, based on postmortem analysis of tissue samples for six individuals, were obtained from the US Transuranium Registry (USTR). Bioassay data and other radiation exposure information obtained from the individuals' files were used to estimate their skeleton and liver burdens at the times of their deaths, and these estimates were compared to those obtained through tissue analysis. 6 refs., 2 tabs.
Date: April 1, 1988
Creator: Sula, M.J.; Bihl, D.E.; Carbaugh, E.H. & Kathren, R.L.
System: The UNT Digital Library
Composite weak bosons (open access)

Composite weak bosons

Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.
Date: April 1, 1988
Creator: Suzuki, M.
System: The UNT Digital Library
Development of high current and high brightness negative hydrogen ion sources (open access)

Development of high current and high brightness negative hydrogen ion sources

Negative hydrogen ions have found important applications in particle accelerators and in fusion research. These ions can be generated from two different types of ion sources---the surface conversion source and the volume production source. Recent experiments demonstrate that H/sup /minus// current exceeding 1 A can be obtained from both types of ion sources. Because of the lower H/sup /minus// ion temperature and the fact that they can be operated without cesium, volume H/sup /minus// sources are highly desired. However, further technology must be developed on the control of electrons and the reduction of gas flow before this type of sources become practical units of a multiampere neutral beam injection system.
Date: April 1, 1988
Creator: Leung, K. N.
System: The UNT Digital Library
The dialogue between particle physics and cosmology (open access)

The dialogue between particle physics and cosmology

In the last decade, a very close relationship has developed between particle physics and cosmology. The purpose of these lectures is to introduce particle physicists to the many scientific connections between the two fields. Before entering into the discussion of specific topics, it will first be shown that particle physics and cosmology are completely interdependent. 173 refs., 35 figs., 5 tabs.
Date: April 1, 1988
Creator: Sadoulet, B.
System: The UNT Digital Library
Electron irradiation effects in YBa/sub 2/Cu/sub 3/O/sub 7-delta/ single crystals (open access)

Electron irradiation effects in YBa/sub 2/Cu/sub 3/O/sub 7-delta/ single crystals

Defect structures in YBa/sub 2/Cu/sub 3/O/sub 7/minus/delta/ produced by electron irradiation at 300/degree/K, were investigated by transmission electron microscopy. Threshold energies for the production of visible defects were determined to b 152 keV and 131 keV (+- 7 keV) in directions near the a- and b-axes, respectively (b > a, both perpendicular to c, the long axis in the orthorhombic structure). During above-threshold irradiations in an electron flux of 3 x 10 /sup 18/ cm/sup /minus/2/s/sup /minus/1/, extended defects were observed to form and grow to sizes of 10--50 nm over 15 minutes, in material thicknesses varying between 20 and 200 nm. Upon irradiation between the a- and b-thresholds, movement of twin plane boundaries and shrinkage of twinned volume were observed. All these findings suggest oxygen atom displacements in the basal plane with recoil energies near 20 eV. Above-threshold irradiations also show the collapse of c-axis long-range order into a planar faulted defect structure with short range order peaks at 1.2 c and 1.07 c, depending on the irradiation direction. 9 refs., 4 figs.
Date: April 1, 1988
Creator: Kirk, M.A.; Baker, M.C.; Liu, J.Z.; Lam, D.J. & Weber, H.W.
System: The UNT Digital Library
The emerging nuclear suppliers: some guidelines for policy (U) (open access)

The emerging nuclear suppliers: some guidelines for policy (U)

Lewis A. Dunn, a former Assistant Director of the US Arms Control and Disarmament Agency and now a senior analyst with Science Applications International Corporation, looks to the future to offer &quot;The Emerging Nuclear Suppliers: Some Guidelines for Policy .&quot; Mr. Dunn notes that although most emerging suppliers are cautious, many are not party to existing nonproliferation treaties. He calls upon the nonproliferation community to continue the present policy of not supporting unsafeguarded nuclear activities. He suggests that the nonproliferation community work within existing standards and infrastructures of nuclear suppliers to convince emerging supplier nations of the merits of nuclear export control.
Date: April 1, 1988
Creator: Dunn, Lewis A.
System: The UNT Digital Library
Erosion/Redeposition Modeling and Calculations for Carbon (open access)

Erosion/Redeposition Modeling and Calculations for Carbon

Several key aspects of carbon erosion/redeposition in fusion devices have been examined. These include the effects of an oblique magnetic field geometry plasma sheath on ion impingement and sputtering, and the effect of surface hydrogen buildup on sputtering. The calculations use a version of the MEASTRI hydrogen implantation code and a cloud-in-cell type sheath code. Time dependent erosion calculations have been made for the TFTR bumper limiter, using the REDEP erosion/redeposition code with updated sheath and sputtering modes. The computed plasma carbon content during a TFTR limiter deconditioning'' run and for a supershot'' beam heating case is similar to measured values. The calculations predict that depletion of the near surface graphite hydrogen concentration enhances the self and hydrogen sputtering coefficients. This mechanism provides an explanation for the larger Z-effective values observed on TFTR immediately after limiter conditioning. 21 refs., 6 figs.
Date: April 1, 1988
Creator: Brooks, J. N.; Brice, D. K.; DeWald, A. B. & McGrath, R. T.
System: The UNT Digital Library
Fast Flux Test Facility (FFTF) feedback reactivity components (open access)

Fast Flux Test Facility (FFTF) feedback reactivity components

The static tests conducted during Cycle 8A (1986) of the FFTF have allowed, for the first time, the experimental determination of each of the feedback reactivities caused by the following mechanisms: fuel axial expansion, control rod repositioning, core radial expansion, and subassembly bowing. A semiempirical equation was obtained to describe each of these feedback components that depended only on the relevant reactor temperature (bowing was presented in a tabular form). The Doppler and sodium density reactivities were calculated using existing mechanistic methods. Although they could also be fitted with closed-form equations depending only on temperatures, these equations are not needed in transient analyses using whole core safety computer codes, which use mechanistic methods. The static feedback reactivity model was extended to obtain a dynamic model via the concept of ''time constants.'' Besides being used for transient analyses in the FFTF, these feedback equations constitute a database for the validation and/or calibration of mechanistic feedback reactivity models. 2 refs., 6 tabs.
Date: April 1, 1988
Creator: Nguyen, D.H.
System: The UNT Digital Library
Fiber Optic Velocity Interferometry (open access)

Fiber Optic Velocity Interferometry

This paper explores the use of a new velocity measurement technique that has several advantages over existing techniques. It uses an optical fiber to carry coherent light to and from a moving target. A Fabry-Perot interferometer, formed by a gradient index lens and the moving target, produces fringes with a frequency proportional to the target velocity. This technique can measure velocities up to 10 km/s, is accurate, portable, and completely noninvasive.
Date: April 1, 1988
Creator: Neyer, Barry T.
System: The UNT Digital Library