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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
Structure of NH/sub 3/ on Ni(111) (open access)

Structure of NH/sub 3/ on Ni(111)

In a recent study of the adsorption of NH/sub 3/ on NI(111) at T approx. 190 K using angle resolved UPS, it was concluded that NH/sub 3/ is molecularly adsorbed, and is bonded to the surface via the N atom with the H atoms oriented away from the surface. To study the bonding configuration using a direct and independent technique, we have examined NH/sub 3/ on Ni(111) using the electron stimulated desorption ion angular distribution (ESDIAD) method, coupled with temperature programmed desorption (TPD) and low energy electron diffraction (LEED). For NH/sub 3/ coverages achievable at T > 150K, (THETA approx. < 0.75 monolayers) the ESDIAD patterns are dominated by a halo of ion emission with little ion yield normal to the surface; the halo pattern is consistent with molecular NH/sub 3/ bonded to Ni via the N atom. Whereas angle-resolved UPS data indicate a specific azimutal registry of NH/sub 3/ with Ni(111) a well-defined azimuthal orientation is not evident from the ESDIAD results. Possible reasons for the differences between these results are examined, including final state effects in ESDIAD, and difference in sensitivity of the two methods to more than one possible configuration of the adsorbed NH/sub 3/.
Date: January 1, 1980
Creator: Madey, T. E.; Houston, J. E.; Seabury, C. W. & Rhodin, T. N.
System: The UNT Digital Library
Silicon mass transfer in sodium loops and the resulting/thermal hydraulic effects. [LMFBR] (open access)

Silicon mass transfer in sodium loops and the resulting/thermal hydraulic effects. [LMFBR]

The element silicon in the surface of new, 300 series stainless steel has been shown to rapidly dissolve in sodium above 525/sup 0/C. It deposits in slightly cooler regions as a crystalline compound with sodium and oxygen. In tests, the deposits have caused increases in hydraulic friction factor (hence, increased pressure loss) of up to 300% at Reynolds Numbers of 14/sup 4/ to 10/sup 5/.Also, they have contributed to local losses of heat transfer rate to 1/10 the original value, at a Reynolds Number of approximately 10/sup 4/. The crystals quickly decompose when out of sodium. Measurements made with a sodium loop (volume = 0.42 m/sup 3/) include compound solubility vs temperature, loop conditions vs source rates and deposit transfer rates. Laboratory examinations and analyses of the crystals have also been made. The effects of this material have been observed also in a number of other loops. With the data from these studies, such effects are now explained and can be controlled or eliminated by system design and operation.
Date: February 1, 1980
Creator: Yunker, W.H.
System: The UNT Digital Library
Application of pressurized ion exchange to separations of transplutonium elements (open access)

Application of pressurized ion exchange to separations of transplutonium elements

High-pressure ion exchange chromatography, used first for nucleic acid separations, was applied to the production of the heavier actinides, particularly the transcurium elements. Its use at the TRU plant is described. Future developments are considered briefly. (DLC)
Date: January 1, 1980
Creator: Campbell, D.O.
System: The UNT Digital Library
Radiation protection: an analysis of thyroid blocking. [Effectiveness of KI in reducing radioactive uptake following potential reactor accident] (open access)

Radiation protection: an analysis of thyroid blocking. [Effectiveness of KI in reducing radioactive uptake following potential reactor accident]

An analysis was performed to provide guidance to policymakers concerning the effectiveness of potassium iodide (KI) as a thyroid blocking agent in potential reactor accident situations, the distance to which (or area within which) it should be distributed, and its relative effectiveness compared to other available protective measures. The analysis was performed using the Reactor Safety Study (WASH-1400) consequence model. Four categories of accidents were addressed: gap activity release accident (GAP), GAP without containment isolation, core melt with a melt-through release, and core melt with an atmospheric release. Cost-benefit ratios (US $/thyroid nodule prevented) are given assuming that no other protective measures are taken. Uncertainties due to health effects parameters, accident probabilities, and costs are assessed. The effects of other potential protective measures, such as evacuation and sheltering, and the impact on children (critical population) are evaluated. Finally, risk-benefit considerations are briefly discussed.
Date: January 1, 1980
Creator: Aldrich, D.C. & Blond, R.M.
System: The UNT Digital Library
Optical fibers and avalanche photodiodes for scintillator counters (open access)

Optical fibers and avalanche photodiodes for scintillator counters

Fine hodoscopes can be made of new scintillating optical fibers and one half inch end-on PMT's. An avalanche photodiode with small size and immunity to magnetic fields remains as a tempting new device to be proven as a photodetector for the fibers.
Date: January 1, 1980
Creator: Borenstein, S R; Palmer, R B & Strand, R C
System: The UNT Digital Library
Absolute polarization standards at medium and high energies. [200 to 900 MeV] (open access)

Absolute polarization standards at medium and high energies. [200 to 900 MeV]

Although measurement of a polarization asymmetry is rather easy, the normalization of the measurement to obtain the analyzing power requires an absolute knowledge of the beam polarization or comparison with a known standard analyzing power. Such calibration standards can be hard to find. This paper concentrates on medium and higher energies, and divides the techniques into four categories: double scattering, polarized target methods, polarized source methods, and theoretical methods. Secondary standards are also discussed, and earlier data are assessed. 52 references, 6 figures. (RWR)
Date: January 1, 1980
Creator: McNaughton, M.W.
System: The UNT Digital Library
Methane entrained in geopressured aquifers, Texas Gulf Coast (open access)

Methane entrained in geopressured aquifers, Texas Gulf Coast

Six tests of geopressured aquifers have yielded between 3.6 to 4.5 m/sup 3//m/sup 3/ (20 to 25 scf/bbl) of gas. These low gas concentrations are attributed to high salinities, that in all tests exceeded 100,000 mg/l, but undersaturated conditions cannot be ruled out completely. Research efforts are designed to delineate the geographic and stratigraphic variations in salinity and to recognize regional and local trends so that zones of lower salinity and higher gas concentration can be identified. Moreover, well logs and seismic data are being used to develop methods of detecting low concentrations of free gas in watered-out gas sands and in thin sands that were considered as noncommercial prior to renewed interest in unconventional gas supplies. (MHR)
Date: July 1, 1980
Creator: Morton, R. A.
System: The UNT Digital Library
Iodine-123 generator/iodination kit: a preliminary report (open access)

Iodine-123 generator/iodination kit: a preliminary report

Preliminary results are described of a xenon-123 filled device to serve as a combination iodine-123 generator/iodination kit. Xenon-123 is produced in the Brookhaven Linac Isotope Producer (BLIP) by the reaction /sup 127/I(p, 5n)/sup 123/Xe. The device consists of a small glass ampoule containing an internal glass breakseal and a flanged neck on which is crimped a multi-injection type septum. The ampoule contains a hydrogen sulfide atmosphere to assure that the iodine generated from the decay of the xenon is in the form of iodide. Following an adequate period for xenon-123 to decay (this period can be used for shipment), a needle is forced through the septum breaking the seal and residual gases are pumped off. The iodine-123 in the form of iodide can then be rinsed from the ampoule with any desired solvent or reagent added directly to the device to carry out an iodination in an enclosed environment. Preliminary results of both iodine recovery and iodinations have been promising.
Date: January 1, 1980
Creator: Richards, P; Prach, T; Srivastava, S C & Meinken, G E
System: The UNT Digital Library
Polarized targets and polarized low energy neutrons at WNR (open access)

Polarized targets and polarized low energy neutrons at WNR

A description of the experimental setup used at the WNR facility to study the interaction of polarized neutrons with polarized samples is given. Planned measurements of the magnetic moments of compound nuclear resonances are discussed.
Date: January 1, 1980
Creator: Delheij, P. P. J.; Morgan, G. L. & Lisowski, P. W.
System: The UNT Digital Library
Analysis of the thorium axial blanket experiments in the PROTEUS reactor (open access)

Analysis of the thorium axial blanket experiments in the PROTEUS reactor

An extensive program of reactor physics experiments in GCFR fuel pin lattices has been completed recently at the PROTEUS critical facility located at EIR laboratory in Switzerland. The PROTEUS reactor consists of a central test zone surrounded by a uranium buffer and thermal driver region. The test lattices included a PuO/sub 2//UO/sub 2/ fuel region with internal and axial blankets of UO/sub 2/, ThO/sub 2/, and thorium metal. Detailed analysis of the thorium-bearing lattices has been performed at EIR and at ORNL in order to validate nuclear data and methods used for reactor physics analysis of advanced GCFR designs.
Date: January 1, 1980
Creator: White, J.R.; Ingersoll, D.T. & Schmocker, U.
System: The UNT Digital Library
Revised GCFR safety program plan (open access)

Revised GCFR safety program plan

This paper presents a summary of the recently revised gas-cooled fast breeder reactor (GCFR) safety program plan. The activities under this plan are organized to support six lines of protection (LOPs) for protection of the public from postulated GCFR accidents. Each LOP provides an independent, sequential, quantifiable risk barrier between the public and the radiological hazards associated with postulated GCFR accidents. To implement a quantitative risk-based approach in identifying the important technology requirements for each LOP, frequency and consequence-limiting goals are allocated to each. To ensure that all necessary tasks are covered to achieve these goals, the program plan is broken into a work breakdown structure (WBS). Finally, the means by which the plan is being implemented are discussed.
Date: May 1, 1980
Creator: Kelley, A. P.; Boyack, B. E. & Torri, A.
System: The UNT Digital Library
Torque ripple in a Darrieus, vertical axis wind turbine (open access)

Torque ripple in a Darrieus, vertical axis wind turbine

Interaction between a steady wind and a rotating, Darrieus, vertical axis wind turbine produces time periodic aerodynamic loads which cause time dependent torque variations, referred to as torque ripple, to occur in the mechanical link between the turbine and the electrical generator. There is concern for the effect of torque ripple upon fatigue life of drive train components and upon power quality. An analytical solution characterizing the phenomenon of torque ripple has been obtained which is based upon a Fourier expansion of the time dependent features of the problem. Numerical results for torque ripple, some experimental data, determination of acceptable levels and methods of controlling it, are presented and discussed.
Date: January 1, 1980
Creator: Reuter, R.C. Jr.
System: The UNT Digital Library
CP violation in the six-quark model (open access)

CP violation in the six-quark model

Some of the recent work on CP violation in the six-quark model is reviewed.
Date: July 1, 1980
Creator: Wise, M.B.
System: The UNT Digital Library
Direct observations of the primary state of radiation damage of ion-irradiated tungsten and platinum (open access)

Direct observations of the primary state of radiation damage of ion-irradiated tungsten and platinum

A brief summary was presented of all the Cornell work on the primary state of radiation damage in ion-irradiated tungsten and platinum. The primary research tool for all this research was the field-ion microscope (FIM); the FIM was ideally suited for this research because of its excellent atomic resolution and the ability to examine the interior of the specimens, as a result of the field-evaporation effect. This paper summarized, in outline form, the following items: (1) the principal experimental quantities determined from the analyses performed on all the individual depleted zones (DZs) observed; (2) the main experimental programs; (3) a number of the more important results and conclusions concerning the vacancy structure of DZs; and (4) the three-dimensional spatial distribution of self-interstitial atoms around DZs in tungsten which had been irradiated and examined in situ at 10/sup 0/K.
Date: July 1, 1980
Creator: Seidman, D. N.; Current, M. I.; Pramanik, D. & Wei, C. Y.
System: The UNT Digital Library
Photoproduction of hydrogen by membranes of green photosynthetic bacteria (open access)

Photoproduction of hydrogen by membranes of green photosynthetic bacteria

Photoproduction of H/sub 2/ from ascorbate by unit-membrane vesicles from Chlorobium limicola f. thiosulfatophilum was achieved with a system containing gramicidin D, tetramethyl-p-phenylenediamine, methyl viologen, dithioerythritol, Clostridium hydrogenase, and an oxygen-scavenging mixture of glucose, glucose oxidase, ethanol, and catalase. Maximum quantum yield was less than one percent. Half maximum rate of H/sub 2/ production occurred at a white-light intensity of approximately 0.15 cm/sup -2/. The reaction was inhibited completely by 0.3% sodium dodecylbenzene sulfonate, 1% Triton X-100, or preheating the vesicles at 100/sup 0/C for 5 minutes. Low concentrations (0.01 and 0.05%) of Triton X-100 about doubled the reaction rate.
Date: January 1, 1980
Creator: Bernstein, J D & Olson, J M
System: The UNT Digital Library
Interface effects on dose distributions in irradiated media (open access)

Interface effects on dose distributions in irradiated media

It has long been recognized that nonuniformities in dose distributions may occur in the immediate vicinity of a boundary between two different media. Considerable work has been done to determine interface effects in media irradiated by photons or in media containing ..beta..- or ..cap alpha..-particle emitters. More recently interface effects have become of interest in additional problems, including pion radiotherapy and radiation effects in electronic microcircuits in space vehicles. These problems arise when pion capture stars or proton-nucleus interactions produce a spectrum of charged nuclear fragments near an interface. The purpose of this paper is to examine interface effects in detail as to their specific origin. We have made Monte Carlo calculations of dose distributions near an interface in a systematic way for a number of idealized cases in order to indicate the separate influences of several factors including different stopping powers of the two media, nonconstancy (e.g., Bragg peak) in the energy loss curve for the particles, different particle spectra in the two media, and curvature of the boundary between the two media.
Date: January 1, 1980
Creator: Wright, H.A.; Hamm, R.N. & Turner, J.E.
System: The UNT Digital Library
Nuclear waste management: storage and disposal aspects (open access)

Nuclear waste management: storage and disposal aspects

Long-term disposal of nuclear wastes must resolve difficulties arising chiefly from the potential for contamination of the environment and the risk of misuse. Alternatives available for storage and disposal of wastes are examined in this overview paper. Guidelines and criteria which may govern in the development of methods of disposal are discussed.
Date: January 1, 1980
Creator: Patterson, B. D.; Dave, S. A. & O'Connell, W. J.
System: The UNT Digital Library
Excited-state proton-transfer kinetics in 1-naphthol, 1-naphthol-sulfonates, and organometallic complexes (open access)

Excited-state proton-transfer kinetics in 1-naphthol, 1-naphthol-sulfonates, and organometallic complexes

The dissociation of 1-naphthol in aqueous solution occurs so rapidly that the fluorescence from the neutral form, ROH, has been previously described as completely extinguished or hardly noticeable. Apparently nearly all of the fluorescence originates from the naphtholate ion. This paper reports on the proton-transfer characteristics of a series of 1-naphthol compounds, and also reports preliminary data on excited-state proton transfer in an organometallic complex of ruthenium.
Date: July 1, 1980
Creator: Shapiro, S. L.; Winn, K. R. & Clark, J. H.
System: The UNT Digital Library
Los Alamos Scientific Laboratory electronic vehicle identification system (open access)

Los Alamos Scientific Laboratory electronic vehicle identification system

A three-digit electronic identification system is described. Digits may be decimal (1000 combinations) or hexidecimal (8192 combinations). Battery-powered transponders are interrogated with a lower-power (1 W) radio signal. Line-of-sight interrogations up to 33 m (100 ft) are possible. Successful interrogations up to 7 m (20 ft) are possible for concealed transponders (that is, in the engine compartment). Vehicles moving at high rates of speed can be interrogated. This system provides data in a computer-compatible RS232 format. The system can be used for other applications with little or no modification. A similar system is in present use for identification and temperature monitoring of livestock. No unforeseen problems exist for expanding the coding scheme to identify larger numbers of objects.
Date: January 1, 1980
Creator: Landt, J. A.; Bobbett, R. E.; Koelle, A. R. & Salazar, P. H.
System: The UNT Digital Library
Preparation of curium-americium oxide microspheres by resin-bead loading (open access)

Preparation of curium-americium oxide microspheres by resin-bead loading

Resin-bead loading and calcination techniques have been used to produce all curium and americium oxide feed material (about 2.2 kg) for HFIR targets since 1971. The process based on Dowex 50W resin has progressed from a series of test runs, through special production runs, into routine production in permanent equipment beginning in 1975. Key attributes of this process are its reliability, high yields, and ease of operation. The process is suited for remote operation in hot cells. Yields approaching 95% are routinely obtained and only one unacceptable product has been generated during routine production operations. There have been no problems in fabricating targets from this oxide or in the subsequent irradiation of these targets. The present scale of production of 150 to 250 g/y supplies the present need and is comparable with the level of other chemical process operations at TRU. Since the annual production is accomplished in two 8 to 12 day periods, there has been no reason to consider further scale-up. However, the rate of production could easily be doubled by simply adding a second set of calcination equipment.
Date: January 1, 1980
Creator: Chattin, F. R.; Benker, D. E.; Lloyd, M. H.; Orr, P. B.; Ross, R. G. & Wiggins, J. T.
System: The UNT Digital Library
Thermal reactor safety (open access)

Thermal reactor safety

Information is presented concerning new trends in licensing; seismic considerations and system structural behavior; TMI-2 risk assessment and thermal hydraulics; statistical assessment of potential accidents and verification of computational methods; issues with respect to improved safety; human factors in nuclear power plant operation; diagnostics and activities in support of recovery; LOCA transient analysis; unresolved safety issues and other safety considerations; and fission product transport.
Date: June 1, 1980
Creator: unknown
System: The UNT Digital Library
High-field bipolar loss measurement apparatus (open access)

High-field bipolar loss measurement apparatus

An apparatus was constructed to measure dissipation in superconducting wire in high alternating fields. The apparatus will be used to make measurements on conductors which must operate in fields up to 7.0 T and rates of field change up to 15 T/s. The magnet for this facility is wound of uninsulated, 15 strand Rutherford cable in which the strand is a 0.812 mm diameter, fully mixed matrix, Cu plus CuNi, multifilament NbTi conductor. The coil is wound in a bath cooled configuration with an overall current density of 7.8 kA/cm/sup 2/. The circuit incorporates a pair of locomotive traction motors as the capacitive circuit element for the bipolar swing. The design, construction and operating characteristics of the field coil and the associated circuitry are described.
Date: January 1, 1980
Creator: Thullen, P.; Weldon, D. & Wollan, J.
System: The UNT Digital Library
Subseabed Radioactive Waste Disposal Feasibility Program: ocean engineering challenges for the 80's (open access)

Subseabed Radioactive Waste Disposal Feasibility Program: ocean engineering challenges for the 80's

The objective of the Subseabed Disposal Program is to assess the feasibility of disposing of high-level radioactive wastes or spent fuel in suitable geologic formations beneath the deep ocean floor. The program is entering a phase which will address engineering feasibility. While the current phase of the program to determine the scientific and environmental feasibility of the concept is not yet complete, activities to assess the engineering aspects are being initiated in parallel to facilitate the development of the concept on a time scale commensurate with other related programs both in the United States and abroad. It is anticipated that engineering aspects will become the central focus of the program during the early 80's and will continue so through the establishment of a pilot-plant level activity which could occur by the mid-90's.
Date: January 1, 1980
Creator: Talbert, D. M.
System: The UNT Digital Library