66 Matching Results

Results open in a new window/tab.

Savannah River Plant defense waste vitrification studies during FY 1982. Summary report (open access)

Savannah River Plant defense waste vitrification studies during FY 1982. Summary report

Five major melter runs were completed during FY 1982 on the Pilot-Scale Ceramic Melter (PSCM). Over 41,000 L of feed were processed by the PSCM, producing approx. 21,000 kg of glass. The design basis reference capacity of approx. 39 kg/h-m/sup 2/ was met or exceeded in all the melter runs. Off-gas characterization was emphasized during this fiscal year. Entrainment of feed material is the largest contributor to the mass of particulate leaving the melter, averaging 0.2 wt% of the incoming feed on an oxide basis. This is a DF of approx. 500. This mass does show an enrichment of some of the volatile and semivolatile components. Higher losses of cesium, tellurium, and cadmium occurred with formate feed. The Experimental Ceramic Melter (ECM) was used this year to study the application of two techniques to increase melting rates in ceramic melters. The first was the use of an air sparger to forcibly agitate the glass in the melter to improve the heat transfer. The air-sparger agitation increased the throughput capacity of the ECM, but did not seem to affect melting efficiency. The second technique for increasing melter rates tested on the ECM was the use of microwave boosting. While significant improvement …
Date: October 1, 1983
Creator: Ethridge, L.J. (comp.)
System: The UNT Digital Library
Cryogenically cooled broad-band GaAs field-effect transistor preamplifier (open access)

Cryogenically cooled broad-band GaAs field-effect transistor preamplifier

The Antiproton Source of the Fermi National Accelerator Laboratory will be capable of accumulating a total of 4.3 x 10/sup 11/ antiprotons in four hours when a wide-band feedback system for stochastic beam cooling is used. The feedback system detects and corrects at every revolution, the statistical fluctuations of the beam position and momentum. One of the essential components of such a system is a low-noise broad-band preamplifier. Acryogenically cooled 1 to 2 GHz low-noise broad-band prototype preamplifier utilizing GaAs field-effect transistors is described for this application. The preamplifier has an average gain of 30 dB and 35 dB at ambient temperatures of 293/sup 0/K and 18/sup 0/K, respectively. The noise figure has a minimum value of 0.75 dB at 300/sup 0/K and 0.24 dB at 18/sup 0/K. The optimum preamplifier operating conditions for a minimum noise figure at temperatures of 293/sup 0/K, 80/sup 0/K and 18/sup 0/K are given and are discussed. Also, the phase-shift characteristics, the input and output voltage standing-wave ratio as a function of frequency and intermodulation products content as a function of the input power level were measured.
Date: October 1, 1983
Creator: Lo, C.C. & Leskovar, B.
System: The UNT Digital Library
Release of volatile fission products from UO/sub 2/ (open access)

Release of volatile fission products from UO/sub 2/

In our experiments, post-irradiation anneal of lightly-irradiated UO/sub 2/ was used to measure the release kinetics of the volatile fission products Xe, I, and Te. The fraction of a particular fission product retained in a specimen was measured by gamma-ray spectroscopy before and following an anneal.
Date: October 1, 1983
Creator: Prussin, S.G.; Olander, D.R.; Goubeault, P. & Bayen, D.
System: The UNT Digital Library
Fast imaging applications in the Nuclear Test Program (open access)

Fast imaging applications in the Nuclear Test Program

Applications of fast imaging employ both streak cameras and fast framing techniques. Image intensifier tubes are gated to provide fast two-dimensional shutters of 2 to 3 ns duration with shatter ratios of greater than 10/sup 6/ and resolution greater than 10/sup 4/ pixels. Shutters of less than 1 ns have been achieved with experimental tubes. Characterization data demonstrate the importance of tube and pulser design. Streak cameras are used to simultaneously record temporal and intensity information from up to 200 spatial points. Streak cameras are combined with remote readout for downhole uses and are coupled to fiber optic cables for uphole uses. Optical wavelength multiplexing is being studied as a means of compressing additional image data onto optical fibers. Performance data demonstrate trade-offs between image resolution and system sensitivity.
Date: October 14, 1983
Creator: Lear, R.
System: The UNT Digital Library
Improved information processing and dissemination through the introduction of new technology (open access)

Improved information processing and dissemination through the introduction of new technology

This paper discusses the following topic on information technology: technology signals a liberation; application of information technology; optical character recognition; optical memories; and planning considerations and the future.
Date: October 1, 1983
Creator: Spath, C E & Marsh, Jr, F E
System: The UNT Digital Library
3D field calculation of the GEM prototype magnet and comparison with measurements (open access)

3D field calculation of the GEM prototype magnet and comparison with measurements

The proposed 4 GeV Electron Microtron (GEM) is designed to fill the existing buildings left vacant by the demise of the Zero Gradient Synchrotron (ZGS) accelerator. One of the six large dipole magnets is shown as well as the first 10 electron orbits. A 3-orbit prototype magnet has been built. The stepped edge of the magnet is to keep the beam exiting perpendicular to the pole. The end guards that wrap around the main coils are joined together by the 3 shield plates. The auxiliary coils are needed to keep the end guards and shield plates from saturating. A 0.3 cm Purcell filter air gap exists between the pole and the yoke. Can anyone question this being a truly three-dimensional magnetostatic problem. The computer program TOSCA, developed at the Rutherford Appleton Laboratory by the Computing Applications Group, was used to calculate this magnet and the results have been compared with measurements.
Date: October 28, 1983
Creator: Lari, R.J.
System: The UNT Digital Library
Large area spark counters with fine time and position resolution (open access)

Large area spark counters with fine time and position resolution

Spark counters trace their history back over three decades but have been used in only a limited number of experiments. The key properties of these devices include their capability of precision timing (at the sub 100 ps level) and of measuring the position of the charged particle to high accuracy. At SLAC we have undertaken a program to develop these devices for use in high energy physics experiments involving large detectors. A spark counter of size 1.2 m x 0.1 m has been constructed and has been operating continuously in our test setup for several months. In this talk I will discuss some details of its construction and its properties as a particle detector. 14 references.
Date: October 1, 1983
Creator: Ogawa, A.; Atwood, W.B.; Fujiwara, N.; Pestov, Yu.N. & Sugahara, R.
System: The UNT Digital Library
Investigation of the Pathway of Contaminated Soil Transported to Plant Surfaces by Raindrop Splash (open access)

Investigation of the Pathway of Contaminated Soil Transported to Plant Surfaces by Raindrop Splash

The environmental transport pathway of soil-borne radioisotopes to vegetation surfaces via raindrop splash was studied. The data show that soil can significantly contribute to the contamination found on plants. Further detailed study is needed to calculate the rate constant for the raindrop splash and retention pathways. 8 references, 1 figure. (ACR)
Date: October 21, 1983
Creator: Dreicer, M.; Hakonson, T. E.; Whicker, F. W. & White, G. C.
System: The UNT Digital Library
Role of the Radiation Pressure Gradient in Giant and Supergiant Star Evolution (open access)

Role of the Radiation Pressure Gradient in Giant and Supergiant Star Evolution

Since some of the earliest evolutionary calculations it has been found that post main sequence stars become red giants (e.g. Sandage and Schwarzschild, 1952). However the exact physical processes that lead to and determine the rate of redward evolution are not completely understood. We hypothesized that the redward evolution might be due to an increase in radiation pressure somewhere in the star that causes the layers above it to be pushed outward, resulting in an expanded envelope and a cooler surface temperature. If the radiative luminosity somewhere in the star approached the Eddington limit, the outer layers would obviously expand. However, due to the presence of gas pressure, the critical value for expansion would be somewhat less than the Eddington limit.
Date: October 7, 1983
Creator: Brunish, W. M.; Cox, A. N.; Becker, S. A. & Despain, K. H.
System: The UNT Digital Library
Review of the 3rd biennial conference on real-time computer applications in nuclear and particle physics (open access)

Review of the 3rd biennial conference on real-time computer applications in nuclear and particle physics

The topics presented at Berkeley centered on computer technologies and architecture as they effect the data-acquisition and data reduction process. Data-acquisition hardware activities were well represented with discussions of CAMAC, FASTBUS, and specialized hardware for data sorting, pipelined operations, and parallel processing. Vendors of CAMAC and FASTBUS products were present to demonstrate their systems and track new research developments and directions.
Date: October 1, 1983
Creator: O'Brien, D.W.
System: The UNT Digital Library
TRIO-01 experiment: in-situ tritium recovery results (open access)

TRIO-01 experiment: in-situ tritium recovery results

The TRIO-01 experiment is a test of in-situ tritium recovery from ..gamma..-LiAlO/sub 2/ with test conditions chosen to simulate those anticipated in fusion power reactors. A status report is presented which describes qualitatively the results observed during the irradiation phase of the experiment. Both the rate of tritium release and the chemical forms of tritium were measured using a helium sweep gas which flowed past the breeder material to a gas analysis system.
Date: October 1, 1983
Creator: Clemmer, R. G.; Finn, P. A.; Billone, M. C.; Misra, B.; Arons, R. M.; Poeppel, R. B. et al.
System: The UNT Digital Library
Ionization equilibrium and equation of state in the solar interior (open access)

Ionization equilibrium and equation of state in the solar interior

Many-body formulations of the equations of state are restated as a set of Saha-like equations. It is shown that the resulting equations are unique and convergent. These equations are similar to the usual Saha equations to the order of the Debye-Hueckel theory. Higher order corrections, however, require a more general formulation. It is demonstrated that the positive free energy resulting from the interaction of unscreened particles in high orbits depletes the occupation of these states, without the introduction of shifted energy levels.
Date: October 10, 1983
Creator: Rogers, F. J.
System: The UNT Digital Library
Properties of b-flavored hadrons (open access)

Properties of b-flavored hadrons

Experimental progress in the study of b-flavored hadrons is reviewed. The observation of the B meson, properties of hadronic B decays, semi-leptonic B decays, and the B lifetime are discussed. 30 references.
Date: October 1, 1983
Creator: Jaros, J. A.
System: The UNT Digital Library
Scales and upper bounds of classical monopole solutions (open access)

Scales and upper bounds of classical monopole solutions

The masses of GUT monopoles are bounded from above by a limit roughly twice the Prasad-Sommerfield limit, and thus depend only weakly on Higgs masses and the electroweak scale. 7 references.
Date: October 1, 1983
Creator: Zachos, Cosmas K.
System: The UNT Digital Library
Study of ion bombardment-induced subsurface compositional modifications in Ni-Cu alloys at elevated temperatures by ion scattering spectroscopy (open access)

Study of ion bombardment-induced subsurface compositional modifications in Ni-Cu alloys at elevated temperatures by ion scattering spectroscopy

Changes in the subsurface composition of Ni-40 at.% Cu alloys during 3-keV Ne/sup +/ bombardment at temperatures between 25 and 700/sup 0/C were studied by means of ion scattering spectroscopy. Both the time evolution of the composition in the surface atom layer during ion bombardment and subsurface concentration profiles after rapid specimen cooling to room temperature were measured as a function of temperature. Radiation-enhanced diffusion coefficients were derived from the effective altered-layer thicknesses obtained. A comparison of the experimental measurements with theoretical calculations based on a phenomenological model enabled the identification of processes and kinetics responsible for subsurface compositional modifications.
Date: October 1, 1983
Creator: Lam, N. Q.; Hoff, H. A.; Wiedersich, H. & Rehn, L. E.
System: The UNT Digital Library
Geologic disposal of radioactive waste, 1983 (open access)

Geologic disposal of radioactive waste, 1983

Geologic repositories for radioactive waste are evolving from conceptualization to the development of specific designs. Estimates of long-term hazards must be based upon quantitative predictions of environmental releases over time periods of hundreds of thousands of years and longer. This paper summarizes new techniques for predicting the long-term performance of repositories, it presents estimates of future environmental releases and radiation doses that may result for conceptual repositories in various geologic media, and it compares these predictions with an individual dose criterion of 10{sup -4} Sv/y. 50 references, 11 figures, 6 tables.
Date: October 1, 1983
Creator: Pigford, T.H.
System: The UNT Digital Library
Selection of barrier metals for a waste package in tuff (open access)

Selection of barrier metals for a waste package in tuff

The Nevada Nuclear Waste Storage Investigations (NNWSI) project under the Civilian Radioactive Waste Management Program is planning a repository at Yucca Mountain at the Nevada Test Site for isolation of high-level nuclear waste. Lawrence Livermore National Laboratory is developing designs for an engineered barrier system containing several barriers such as the waste form, a canister and/or an overpack, packing, and near field host rock. In this paper we address the selection of metal containment barriers. 13 references, 4 tables.
Date: October 1, 1983
Creator: Russell, E.W.; McCright, R.D. & O`Neal, W.C.
System: The UNT Digital Library
A Pyrovidicon-based Inspection System for Nuclear Reactor Safety (open access)

A Pyrovidicon-based Inspection System for Nuclear Reactor Safety

At the Savannah River Nuclear Facility irradiated assemblies are conveyed through the air from the reactor to a discharge/entry channel, where they are immersed in water. This paper addresses the monitoring of the temperature of these assemblies while they are in transit during the discharge cycle. To accomplish this, a remotely controlled and monitored radiation-hardened thermal imaging and alarm system was installed at each reactor. The paper will discuss the system concept and operation. The program for radiation hardening and testing this equipment will be reviewed.
Date: October 12, 1983
Creator: Lynam, E.C.
System: The UNT Digital Library