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Parity violation in polarized electron scattering (open access)

Parity violation in polarized electron scattering

The weak forces are responsible for the decay of radioactive nuclei, and it was in these decay processes where parity non-conservation was first observed. Beta decay occurs through emission of e/sup +/ or e/sup -/ particles, indicating that the weak force can carry charge of both signs, and it was natural to speculate on the existence of a neutral component of the weak force. Even though weak neutral forces had not been observed it was conjectured that a neutral component of weak decay could exist, and Zel'dovich in 1957 suggested that parity violating effects may be observable in electron scattering and in atomic spectra. More than twenty years have passed since the early conjectures, and a great deal has been learned. Progress in quantum field theory led to the development of the SU(2) x U(1) gauge theory of weak and electromagnetic interactions and provided a renormalizable theory with a minimum of additional assumptions. Gauge theories predicted the existence of a new force, the neutral current interaction. This new interaction was first seen in 1973 in the Gargamelle bubble chamber at CERN. Today the neutral currents are accepted as well established, and it is the details of the neutral current structure …
Date: October 1, 1980
Creator: Prescott, Charles Y.
System: The UNT Digital Library
High intensity polarized electron sources (open access)

High intensity polarized electron sources

The status of the polarized electron source development program at SLAC will be reviewed. Emission currents of 60 A, corresponding to a space charge limited current density of 180 A/cm/sup 2/, have been obtained from GaAs photocathodes. Electron beam polarization 20% greater than that obtainable from GaAs cathodes has been observed from multilayer GaAs-GaAlAs structures. Work in progress to produce high beam polarization from II-IV-V/sub 2/ chalcopyrite photocathodes will also be described.
Date: October 1, 1980
Creator: Sinclair, C. K.
System: The UNT Digital Library
Maintaining ideal body weight counseling sessions (open access)

Maintaining ideal body weight counseling sessions

The purpose of this program is to provide employees with the motivation, knowledge and skills necessary to maintain ideal body weight throughout life. The target audience for this program, which is conducted in an industrial setting, is the employee 40 years of age or younger who is at or near his/her ideal body weight.
Date: October 9, 1980
Creator: Brammer, S. H.
System: The UNT Digital Library
Scale-model characterization of flow-induced vibrational response of FFTF reactor internals (open access)

Scale-model characterization of flow-induced vibrational response of FFTF reactor internals

Fast Test Reactor core internal and peripheral components were assessed for flow-induced vibrational characteristics under scaled and simulated prototype flow conditions in the Hydraulic Core Mockup as an integral part of the Fast Test Reactor Vibration Program. The Hydraulic Core Mockup was an 0.285 geometric scale model of the Fast Test Reactor internals designed to simulate prototype vibrational and hydraulic characteristics. Using water to simulate sodium coolant, vibrational characteristics were measured and determined for selected model components over the scaled flow range of 36 to 110%. Additionally, in-situ shaker tests were conducted on selected Hydraulic Core Mockup outlet plenum components to establish modal characteristics. Most components exhibited resonant response at all test flow rates; however, the measured dynamic response was neither abnormal nor anomalously flow-rate dependent, and the predicted prototype components' response were deemed acceptable.
Date: October 1, 1980
Creator: Ryan, J. A. & Mahoney, J. J.
System: The UNT Digital Library
delta. -nucleus interactions. CTP No. 887 (open access)

delta. -nucleus interactions. CTP No. 887

The theoretical description of pion-nucleus interactions, specifically in the intermediate-energy region dominated ..delta..-excitation, is discussed. Attention is focused on the interaction with and propagation through the nucleus of pions and ..delta..'s. The approach followed basically consists of viewing the ..delta..-nucleus system, formed by pion excitation of a nucleon, as a doorway for the pion-nucleus reaction. Analysis of the interacting ..delta..-nucleus system then leads to new dynamical information summarized in a complex ..delta..-nucleus interaction potential. The associated nuclear medium corrections to ..delta.. propagation, related in more conventional language to higher-order corrections in the pion optical potential, are so large as to demand consideration in quantitative studies of nuclear structure with pions. After a discussion of the basic scale parameters characterizing intermediate-energy pion-nucleus interactions, the author discusses the theoretical framework and the extraction of ..delta.. interaction parameters from inclusive pion-nucleus cross sections. More detailed tests of the picture, such as elastic scattering angular distributions, are then discussed. Finally, some implications for intermediate-energy photoreactions are outlined. 11 figures. (RWR)
Date: October 1, 1980
Creator: Moniz, E.J.
System: The UNT Digital Library
Proceedings of the CSNI specialists meeting on nuclear aerosols in reactor safety (open access)

Proceedings of the CSNI specialists meeting on nuclear aerosols in reactor safety

Separate abstracts were prepared for 30 papers in this report. (JDB)
Date: October 1, 1980
Creator: Kress, T.S. (comp.)
System: The UNT Digital Library
Design and performance of the new cathode readout proportional chambers in LASS (open access)

Design and performance of the new cathode readout proportional chambers in LASS

The design and construction of a new proportional chamber system for the LASS spectrometer are discussed. This system consists of planar and cylindrical chambers employing anode wire and cathode strip readout techniques. The good timing characteristics of anode readout combine with the excellent spatial resolution of cathode readout to provide powerful and compact detectors. Preliminary resolution data are presented along with operating characteristics of the various devices.
Date: October 1, 1980
Creator: Aiken, G.; Aston, D. & Dunwoodie, W.
System: The UNT Digital Library
Severe accident sequence assessment for boiling water reactors: program overview (open access)

Severe accident sequence assessment for boiling water reactors: program overview

The Severe Accident Sequence Assessment (SASA) Program was started at the Oak Ridge National Laboratory (ORNL) in June 1980. This report documents the initial planning, specification of objectives, potential uses of the results, plan of attack, and preliminary results. ORNL was assigned the Brown's Ferry Unit 1 Plant with the station blackout being the initial sequence set to be addressed. This set includes: (1) loss of offsite and onsite ac power with no coolant injection; and (2) loss of offsite and onsite ac power with high pressure coolant injection (HPCI) and reactor core isolation cooling (RCIC) as long as dc power supply lasts. This report includes representative preliminary results for the former case.
Date: October 1, 1980
Creator: Fontana, M. H.
System: The UNT Digital Library
Calculational comparison of DT, neon, and argon implosions (open access)

Calculational comparison of DT, neon, and argon implosions

A number of laboratories have been doing laser driven implosions of pure neon and argon gas as a diagnostic of the peak imploded conditions. The relationship of these implosions to DT implosions has been unclear. This paper will explore the physics of these higher Z gases and show that they are fundamentally easier to compress than DT gas. Specifically, this paper will show that, for the same initial mass density, and the same capsule design and drive conditions, the calculated peak compressed density is dependent on the type of fill gas, being substantially higher for Ne and Ar implosions than for DT implosions.
Date: October 28, 1980
Creator: Stevens, J. C.
System: The UNT Digital Library
Prediction of deformations during gas-tungsten-arc stationary welds (open access)

Prediction of deformations during gas-tungsten-arc stationary welds

Local temperature measurements on the heated and unheated surfaces, and strain measurements on the unheated surfaces of unrestrained circular weld specimens of annealed and cold-rolled Nitronic 40 stainless steel during stationary welding, are compared with values predicted from finite-element programs for temperature and strain variations. Experimental and predicted temperature histories agree within 10%. Predicted and measured hoop strain profiles (using a moire fringe technique), for the unheated surface are compared, showing significant deviations near the central region. Transient deflection measurements of the unheated specimen surfaces show good agreement with theory during the period the arc is operating. Close agreement in deflection behavior was observed during the cooling portion of the weld cycle for the annealed specimen, whereas substantial deviations occurred for the cold-rolled specimens.
Date: October 1, 1980
Creator: Duncan, D.B. & Giedt, W.H.
System: The UNT Digital Library
MAGRAC: a railgun simulation program (open access)

MAGRAC: a railgun simulation program

A computer simulation code has been developed and validated at the Lawrence Livermore National Laboratory (LLNL) to predict the performance of a railgun electromagnetic accelerator. The code, called MAGRAC (MAGnetic Railgun ACcelerator), models the performance of a railgun driven by a magnetic flux compression current generator (MFCG). The MAGRAC code employs a time-step solution of the nonlinear time-varying element railgun circuit to determine rail currents. From the rail currents, the projectile acceleration, velocity, and position is found. The MAGRAC code was validated through a series of eight railgun tests conducted jointly with the Los Alamos Scientific National Laboratory. This paper describes the formulation of the MAGRAC railgun model and compares the predicted current waveforms with those obtained from full-scale experiments.
Date: October 24, 1980
Creator: Deadrick, F. J.; Hawke, R. S. & Scudder, J. K.
System: The UNT Digital Library
Picosecond x-ray measurements from 100 eV to 30 keV (open access)

Picosecond x-ray measurements from 100 eV to 30 keV

Picosecond x-ray measurements relevant to the Livermore Laser Fusion Program are reviewed. Resolved to 15 picoseconds, streak camera detection capabilities extend from 100 eV to higher than 30 keV, with synchronous capabilities in the visible, near infrared, and ultraviolet. Capabilities include automated data retrieval using charge coupled devices (CCD's), absolute x-ray intensity levels, novel cathodes, x-ray mirror/reflector combinations, and a variety of x-ray imaging devices.
Date: October 15, 1980
Creator: Attwood, D.T.; Kauffman, R.L. & Stradling, G.L.
System: The UNT Digital Library
MFTF-progress and promise (open access)

MFTF-progress and promise

The Mirror Fusion Test Facility (MFTF) has been in construction at Lawrence Livermore National Laboratory (LLNL) for 3 years, and most of the major subsystems are nearing completion. Recently, the scope of this project was expanded to meet new objectives, principally to reach plasma conditions corresponding to energy break-even. To fulfill this promise, the single-cell minimum-B mirror configuration will be replaced with a tandem mirror configuration (MFTF-B). The facility must accordingly be expanded to accomodate the new geometry. This paper briefly discusses the status of the major MFTF subsystems and describes how most of the technological objectives of MFTF will be demonstrated before we install the additional systems necessary to make the tandem. It also summarizes the major features of the expanded facility.
Date: October 3, 1980
Creator: Thomassen, K.I.
System: The UNT Digital Library
Chemical and catalytic properties of elemental carbon (open access)

Chemical and catalytic properties of elemental carbon

Elemental carbon particles resulting from incomplete combustion of fossil fuel are one of the major constituents of airborne particulate matter. These particles are a chemically and catalytically active material and can be an effective carrier for other toxic air pollutants through their adsorptive capability. The chemical, adsorptive, and catalytic behaviors of carbon particles depend very much on their crystalline structure, surface composition, and electronic properties. This paper discusses these properties and examines their relevance to atmospheric chemistry.
Date: October 1, 1980
Creator: Chang, S. G.; Brodzinsky, R.; Gundel, L. A. & Novakov, T.
System: The UNT Digital Library
Tandem mirror next step: remote maintenance (open access)

Tandem mirror next step: remote maintenance

This study of the next proposed experiment in the Mirror Fusion Program, the Tandem Mirror Next Step (TMNS), has included serious consideration of the maintenance requirements of such a large source of high energy neutrons with its attendant throughput of tritium. Although maintenance will be costly in time and money, our conclusion is that with careful attention to a design for maintenance plan such a device can be reliably operated.
Date: October 27, 1980
Creator: Doggett, J. N.; Damm, C. C. & Hanson, C. L.
System: The UNT Digital Library
Concept for testing fusion first wall/blanket systems in existing nuclear facilities (open access)

Concept for testing fusion first wall/blanket systems in existing nuclear facilities

A novel concept to produce a reasonable simulation of a fusion first wall/blanket test environment (except the 14 MeV neutron component) employing an existing nuclear facility is presented. Preliminary results show that an asymmetric, nuclear test environment with surface and volumetric heating rates similar to those expected in a fusion first wall/blanket or divertor chamber surface appears feasible. The proposed concept takes advantage of nuclear reactions within the annulus of a test space (15 cm in diameter and approximately 100 cm high) to provide an energy flux to the surface of a test module.
Date: October 1, 1980
Creator: Hsu, P. Y. S.; Bohn, T. S.; Deis, G. A.; Judd, J. L.; Longhurst, G. R.; Miller, L. G. et al.
System: The UNT Digital Library
Neutron scattering experiments on the magnetism in Cu-Mn single crystals (open access)

Neutron scattering experiments on the magnetism in Cu-Mn single crystals

Neutron polarization analysis experiments, and unpolarized neutron scattering experiments, were made on annealed single crystal Cu-Mn samples of 5, 10, 15, and 25 at. % Mn. Peaks in the magnetic diffuse scattering are found at the (1, 1/2 +- delta, 0)-type positions in reciprocal space, where delta = 0.34, 0.29, 0.25 and 0.19 for the 5, 10, 15 and 25% Mn samples respectively. This magnetic scattering is symmetry-related to the diffuse nuclear scattering centered at the (1, 1/2, 0)-type positions arising from atomic short range order. The intensity of this diffuse magnetic scattering in all of the alloys decreases smoothly with temperature, approaching zero in the range 300 to 350/sup 0/K. The spin-spin correlation range, as judged from the width of the magnetic diffuse peaks, also decreases smoothly with temperature. Neither the width nor the intensity of this magnetic scattering gives any hint of a freezing transition at lower temperatures.
Date: October 1, 1980
Creator: Werner, S.A. & Cable, J.W.
System: The UNT Digital Library
Characterization of iron-enriched synthetic basalt for transuranic containment (open access)

Characterization of iron-enriched synthetic basalt for transuranic containment

In the slagging pyrolytic incineration process, combustibles are burned and noncombustibles, including metals, are oxidized into a molten , an electromelter, where the molten slag, with further processing conducted in a heated tundish, e.g. is allowed to homogenize (within a reasonable time period) and then cast into large, cylindrical metal containers. Analyses of Idaho National Engineering Laboratory waste slags show them similar in composition and appearance to natural basalts, but rich in iron. The electromelt process and the resulting iron-rich castings offer great promise for rendering nuclear waste into a stable form. The process offers great flexibility with regard to both compositional variation of the incoming waste and the high rates at which the waste can be introduced and cast. The cast product, a fine-grained basalt-like material, shows excellent homogeneity with little or no reaction to the steel containment. The preliminary mechanical and chemical durability data show the form to have adequate containment properties for TRU waste. However, work presently underway to improve these properties through additives and controlled cooling cycles has greatly enhanced the durability of the waste form. Furthermore, recent evidence indicates that divalent iron (Fe/sup 2 +/) included in the crystalline phases of granites and basalts imparts …
Date: October 17, 1980
Creator: Flinn, J. E.; Henslee, S. P.; Kelsey, P. V.; Tallman, R. L. & Welch, J. M.
System: The UNT Digital Library
Synchrotrons for heavy ions: Bevalac experience (open access)

Synchrotrons for heavy ions: Bevalac experience

The Bevalac should be viewed not as a model of accelerator hardware - a modern heavy ion complex will look quite different, but as a model for an operating versatile multifaceted, multiuser heavy ion facility. Of value to the planning of a new accelerator such as MARIA is the knowledge of operating modes peculiar to heavy ions and specific hardware requirements to carry out its mission with the mandated flexibility and reliability. This paper starts with a discussion of parameters and machine characteristics most suitable for medical and nuclear science applications. It then covers experience in interleaving these two research programs, and finally, concentrates on accelerator configuratin questions; injectors, repetition rate, vacuum systems and cost criteria which will be relevant to the design of MARIA.
Date: October 1, 1980
Creator: Grunder, H. A.; Gough, R. A. & Alonso, J. R.
System: The UNT Digital Library
Modular stand-alone monitor and control system (SAMAC) (open access)

Modular stand-alone monitor and control system (SAMAC)

Large high energy physics experiments require constant monitoring and control of the numerous components of the particle detector apparatus. This paper describes a basic hardware configuration which has been designed to satisfy the monitoring and control requirements of the many different experimental setups. The system is designed to operate in the stand-alone mode, and may be interfaced to a host computer via CAMAC. The entire system is modular so that it can be easily tailored to an individual experiment. The items monitored and/or controlled may include gas pressures, temperatures, magnetic fields, high and low voltages, and system status or safety information.
Date: October 1, 1980
Creator: Kieffer, J.
System: The UNT Digital Library
Low noise PWC cathode readout system (open access)

Low noise PWC cathode readout system

A system has been developed, primarily to detect the induced charge deposited on PWC cathodes, which is versatile, fast and has a good signal to noise ratio for signals of greater than or equal to 10/sup -14/ Coulomb input. The amplifier system, which is completely separated from the detector by 95 ..cap omega.. coaxial cables, is followed by a new charge integrating, version of the SHAM/BADC system developed at SLAC. This SHAM IV system is CAMAC based, allowing for computer calibration of the entire system from amplifier through ADC.
Date: October 1, 1980
Creator: Cisneros, E.; Hutchinson, D.; McShurley, D.; Richter, R. & Shapiro, S.
System: The UNT Digital Library
Plasma equilibrium control in doublet III (open access)

Plasma equilibrium control in doublet III

The control signals used for the flux surface position regulation are derived from measurements of the poloidal field and flux obtained with an array of sensors located immediately outside the vacuum vessel. The close proximity of the sensors to the plasma surface (less than or equal to 0.2a) allows the position of the plasma surface to be accurately computed with simple analog circuitry. The short time constant of the resistive vessel allows for stable high-gain closed loop control without elaborate pole-zero compensation. The small-signal response time is typically less than 10 msec. Control of the plasma position to +-0.5 cm is routine.
Date: October 1, 1980
Creator: Stambaugh, R.; Adcock, S.; Callis, R.; deGrassie, J.; Luxon, J.; Rock, P. et al.
System: The UNT Digital Library
Soot in the atmosphere (open access)

Soot in the atmosphere

The principal goal of the research described is to assess quantitatively the relative amounts of primary and secondary carbonaceous material in atmospheric aerosols and to differentiate between secondary carbonaceous species produced by photochemical and nonphotochemical reactions. The approach used most extensively involves the use of an optical attenuation technique, combined with total particulate carbon determination. The black component of soot, which is an unambiguous tracer for primary emissions, can be conveniently monitored because of its large and uniform optical absorptivity. The black carbon content of the particles can easily be determined by an optical attenuation method. Determination of total particulate carbon mass enables the study of the relations between the black and the total carbon content.
Date: October 1, 1980
Creator: Novakov, T.
System: The UNT Digital Library
Process for controlling accidents in chemical laboratories (open access)

Process for controlling accidents in chemical laboratories

Most laboratory safety programs include inspections to identify hazards and thereby control accidents. There are certain elements that must be a part of a successful inspection and control process. These are a systematic and consistent inspection procedure, a reliable evaluation of identified hazards, and effective follow-up actions. Laboratory management, through its responsibility for the total system, has a key role in the inspection and control process for follow-up actions and accepting risks. If any of the above requirements are missing, the process will be less than adequate. Understanding the relationship between accidents, hazards, and risks is important in establishing an effective inspection and control program. Hazards are potential sources of accidents (accidents waiting to happen). Associated with each is a risk, which has two components: probability and consequence. Probability refers to the likelihood that a hazard will turn into an accident and consequence is the result of such an accident. In assessing the seriousness of a hazard, both probability and consequence must be considered in terms of risk level and acceptability. This paper presents a process that can be used by laboratory management to establish an effective inspection and control program for the laboratory. A discussion of safety concepts and …
Date: October 1, 1980
Creator: Delvin, W.L.
System: The UNT Digital Library