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Leak rate measurements and detection systems (open access)

Leak rate measurements and detection systems

A research program is under way to evaluate and develop improve leak detection systems. The primary focus of the work has been on acoustic emission detection of leaks. Leaks from artificial flaws, laboratory-generated IGSCCs and thermal fatigue cracks, and field-induced intergranular stress corrosion cracks (IGSCCs) from reactor piping have been examined. The effects of pressure, temperature, and leak rate and geometry on the acoustic signature are under study. The use of cross-correlation techniques for leak location and pattern recognition and autocorrelation for source discrimination is also being considered.
Date: October 1, 1983
Creator: Kupperman, D.; Shack, W.J. & Claytor, T.
System: The UNT Digital Library
Jets in e/sup +/e/sup -/ annihilation (open access)

Jets in e/sup +/e/sup -/ annihilation

We have a simple perturbative picture of the production of hadrons from e/sup +/e/sup -/ annihilations which works quite well in predicting the main features of this interaction. It explains the magnitude of the total cross-section, the basic two-jet structure, and the final state angular distributions. It is also consistent with our present ideas about the structure of hadronic matter and the requirement that at high enough energies, the corrections due to strong interactions are small and hence treatable in a perturbative sense. We have seen, however, that to progress beyond this point requires a detailed model of fragmentation phenomena and that differences in models prevent us from making clean predictions about QCD. It is therefore important that we continue to study the fragmentation process and try to parameterize it as well as possible. Large amounts of experimental data are now available on this subject, and new tests will become available as experimenters look in more detail at the behavior of quantum number correlations and energy dependent effects. In doing this, it will be important to keep in mind that mass effects can yield significant energy variations in the model parameters. Our eventual goal should be to find ways of …
Date: October 1, 1983
Creator: Hollebeek, R.
System: The UNT Digital Library
Comparison of fission neutron and pulsed spallation neutron sources for radiation effects experiments on Cu/sub 3/Au (open access)

Comparison of fission neutron and pulsed spallation neutron sources for radiation effects experiments on Cu/sub 3/Au

Through our recent experimental work on the neutron irradiation effects in Cu/sub 3/Au, we will compare fission and pulsed spallation neutron sources. Neutron characteristics of irradiation facilities at the Intense Pulsed Neutron Source (IPNS) and the CP-5 reactor (now closed down), are briefly described. Defect cascade size distributions from irradiations of Cu/sub 3/Au at both neutron sources illustrated by transmission electron micrographs of disordered zones. Radiation-enhanced diffusion experiments in Cu/sub 3/Au are discussed along with the effect of pulsed neutron irradiations.
Date: October 1, 1983
Creator: Kirk, M.A.
System: The UNT Digital Library
Characterization of the TEXTOR plasma edge using deposition probe techniques (open access)

Characterization of the TEXTOR plasma edge using deposition probe techniques

Carbon and single crystal silicon passive deposition probes were used to measure the characteristics of the plasma edge region of the TEXTOR tokamak. Analysis of the probes was done by Rutherford backscattering for impurities and nuclear reaction analysis and elastic recoil detection for hydrogen isotopes. Plasma fluxes and energies in the edge were measured using probe techniques. The principal impurities in the plasma edge were determined and their behavior as a function of time and position was measured. Measurements were also made of in situ erosion rates. The results are compared with independent measurements of other plasma parameters to study possible impurity introduction mechanisms. This work represents the first deposition probe measurements made in the plasma edge of TEXTOR.
Date: October 1, 1983
Creator: Zuhr, R.A.
System: The UNT Digital Library
Theory of elementary excitations in intermediate valence materials (open access)

Theory of elementary excitations in intermediate valence materials

We review the formalism for calculating the properties of systems represented by an Anderson lattice Hamiltonian. First, a mean-field theory for the one electron Green's function is presented and then extended to include spin and charge fluctuations which lead to a many-body resonance near the Fermi level. The dynamical spin susceptibility and neutron scattering cross section are also evaluated. Finally, we present a calculation which indicates the possibility of a Cooper-pairing mechanism induced by electron correlations.
Date: October 1, 1983
Creator: Fedro, A.J. & Sinha, S.K.
System: The UNT Digital Library
Line intensities for diagnosing laser-produced plasmas (open access)

Line intensities for diagnosing laser-produced plasmas

We have measured relative line intensities of the K x-ray spectra of Si, Cl, and Ca from laser-produced plasmas to assess their usefulness as a plasma diagnostic. The different elements are added at low concentrations to CH disks which are irradiated at 5 x 10/sup 14/ W/cm/sup 2/ with a 0.53 ..mu..m laser pulse of 20 Joules at 1 nsec. The concentration of each element is kept low in order not to change the Z of the plasma, and therefore the plasma dynamics. The various spectra are measured with a time-resolved spectrograph to obtain line intensities as a function of time over the length of the laser pulse. These relative intensities of various He-like and H-like lines are compared with calculations from a steady-state level population code. The results give good consistency among the various line ratios. Agreement is not as good for analysis of the Li-like satellite lines. Modelling of the Li-like lines need further investigation. 10 references, 9 figures.
Date: October 31, 1983
Creator: Kauffman, R.L.; Matthews, D.L.; Lee, R.W.; Whitten, B.L. & Kilkenny, J.D.
System: The UNT Digital Library
Dislocation sweeping of defects in neutron- and electron-irradiated niobium (open access)

Dislocation sweeping of defects in neutron- and electron-irradiated niobium

The glide of dislocations in a (441)-oriented Nb single crystal irradiated at 325 K with 5.5 x 10/sup 21/ neutrons/m/sup 2/ (E > 0.1 MeV) is shown for increasing time of tensile elongation (2 x 10/sup -4/ mm/s) in the High Voltage Electron Microscope at Argonne National Laboratory. The dimensions of the tensile specimen in the guage length were approximately 2 mm x 0.5 mm x 0.0001 mm. An electron energy of 900 keV was used during the simultaneous deformation and TEM observation.
Date: October 1, 1983
Creator: Loomis, B. A. & Otero, M. P.
System: The UNT Digital Library
Report of the Storage Ring Design Group (open access)

Report of the Storage Ring Design Group

The Storage Ring Design Group set itself the tasks of (1) agreeing on the basic formulas with which one designs (conceptually) a Free Electron Laser (FEL) ring, (2) making three examples employing these formulas, and (3) studying the performance of these rings under the assumption that they have been built and that there are operating parameters that can be varied. The study group made good progress on Task No. 1, and the work is described in Section I. We had time under Task No. 2 to produce only one example and this is described in Section II. The group was unable to attack Task No. 3 in the limited time which we had available. However, the subject is of sufficient interest that the two of us, and C. Pellegrini, intend to go on and do a more extensive job on Task No. 2 and some work on Task No. 3, with the thought that out of this survey will come some generally interesting conceptual designs for FEL rings. Although this group was able to produce only one example, it was a most interesting example. We have shown that a FEL ring designed for 500 Angstroms lasing appears to be within …
Date: October 1, 1983
Creator: Peterson, J. M. & Sessler, A. M.
System: The UNT Digital Library
Acoustic leak detection and ultrasonic crack detection (open access)

Acoustic leak detection and ultrasonic crack detection

A program is under way to assess the effectiveness of current and proposed techniques for acoustic leak detection (ALD) in reactor coolant systems. An ALD facility has been constructed and tests have begun on five laboratory-grown cracks (three fatigue and two thermal-fatigue and two field-induced IGSCC specimens. After ultrasonic testing revealed cracks in the Georgia Power Co. HATCH-1 BWR recirculation header, the utility installed an ALD system. Data from HATCH-1 have given an indication of the background noise level at a BWR recirculation header sweepolet weld. The HATCH leak detection system was tested to determine the sensitivity and dynamic range. Other background data have been acquired at the Watts Bar Nuclear Reactor in Tennessee. An ANL waveguide system, including transducer and electronics, was installed and tested on an accumulator safety injection pipe. The possibility of using ultrasonic wave scattering patterns to discriminate between IGSCCs and geometric reflectors has been explored. Thirteen reflectors (field IGSCCs, graphite wool IGSCCs, weld roots, and slits) were examined. Work with cast stainless steel (SS) included sound velocity and attenuation in isotropic and anisotropic cast SS. Reducing anisotropy does not help reduce attenuation in large-grained material. Large artificial flaws (e.g., a 1-cm-deep notch with a 4-cm …
Date: October 1, 1983
Creator: Kupperman, D.S.; Claytor, T.N. & Groenwald, R.
System: The UNT Digital Library
Comparisons of hydrodynamic beam models with kinetic treatments (open access)

Comparisons of hydrodynamic beam models with kinetic treatments

Hydrodynamic models have been derived by Mark and Yu and by others to describe energetic self-pinched beams, such as those used in ion-beam fusion. The closure of the Mark-Yu model is obtained with adiabatic assumptions mathematically analogous to those of Chew, Goldberger, and Low for MHD. The other models treated here use an ideal gas closure and a closure by Newcomb based on an expansion in V/sub th//V/sub z/. Features of these hydrodynamic beam models are compared with a kinetic treatment.
Date: October 6, 1983
Creator: Boyd, J. K.; Mark, J. W.; Sharp, W. M. & Yu, S. S.
System: The UNT Digital Library
Development of an operational multicomponent personnel neutron dosimeter/spectrometer DOSPEC (open access)

Development of an operational multicomponent personnel neutron dosimeter/spectrometer DOSPEC

A multicomponent dosimeter has been developed that uses an albedo detector to provide the measurement of low energy neutrons and as a screening element. It also contains track detector components, CR-39 and polycarbonate, which are only processed if the TLD indicates there has been an exposure to neutrons. Since the three components have significantly different energy responses, the dosimeter can act as a crude spectrometer. This report describes the dosimeter and briefly summarizes its use experience. 10 refs., 2 figs., 2 tabs.
Date: October 26, 1983
Creator: Griffith, R.V. & McMahon, T.A.
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
Fabrication of a Set of Realistic Torso Phantoms for Calibration of Transuranic Nuclide Lung Counting Facilities (open access)

Fabrication of a Set of Realistic Torso Phantoms for Calibration of Transuranic Nuclide Lung Counting Facilities

A set of 16 tissue equivalent torso phantoms has been fabricated for use by major laboratories involved in counting transuranic nuclides in the lung. These phantoms, which have bone equivalent plastic rib cages, duplicate the performance of the DOE Realistic Phantom set. The new phantoms (and their successors) provide the user laboratories with a highly realistic calibration tool. Moreover, use of these phantoms will allow participating laboratories to intercompare calibration information, both on formal and informal bases. 3 refs., 2 figs.
Date: October 26, 1983
Creator: Griffith, R. V.; Anderson, A. L.; Sundbeck, C. W. & Alderson, S. W.
System: The UNT Digital Library
Control of gas input and background pressure in the end plug regions of the TMX-U thermal barrier experiment (open access)

Control of gas input and background pressure in the end plug regions of the TMX-U thermal barrier experiment

Rate equations for the plasma species in a thermal barrier end plug establish an upper bound on the neutral pressure (P) external to the plasma. For the Tandem Mirror Experiment-Upgrade (TMX-U), this bound is P less than or equal to 0.5 - 1.0 x 10/sup -6/ Torr. Initially TMX-U did not satisfy this criterion, and axial end plugging of plasma losses seemed limited by the excessive pressure. Subsequently, we modified the machine to improve the vacuum conditions, decreasing P to the desired range. At the same time axial end plugging of plasma losses increased to the duration of neutral beam injection and ECRH heating. Here we summarize our experimental measurements of gas input.
Date: October 26, 1983
Creator: Turner, W. C.; Nexsen, W. E.; Allen, S. L.; Hooper, E. B.; Hunt, A. L.; Lang, D. D. et al.
System: The UNT Digital Library
Linearity and resolution of photodiodes (open access)

Linearity and resolution of photodiodes

Measurements are reported of the resolution and linearity of Hamamatsu S1337 Photodiodes mounted on a NaI crystal and exposed to electron energy deposits of up to 80 GeV. The results indicate that these diodes can replace photomultipliers in high-light-yield detectors such as NaI and BGO, when operated in multi-element, compact assemblies in the presence of a magnetic field.
Date: October 1, 1983
Creator: van Driel, M.A. & Sens, J.C.
System: The UNT Digital Library
Memory intensive functional architecture for distributed computer control systems (open access)

Memory intensive functional architecture for distributed computer control systems

A memory-intensive functional architectue for distributed data-acquisition, monitoring, and control systems with large numbers of nodes has been conceptually developed and applied in several large-scale and some smaller systems. This discussion concentrates on: (1) the basic architecture; (2) recent expansions of the architecture which now become feasible in view of the rapidly developing component technologies in microprocessors and functional large-scale integration circuits; and (3) implementation of some key hardware and software structures and one system implementation which is a system for performing control and data acquisition of a neutron spectrometer at the Brookhaven High Flux Beam Reactor. The spectrometer is equipped with a large-area position-sensitive neutron detector.
Date: October 1, 1983
Creator: Dimmler, D.G.
System: The UNT Digital Library
Formation of H/sup -/ by charge transfer in alkaline-earth vapors (open access)

Formation of H/sup -/ by charge transfer in alkaline-earth vapors

Progress on the study of H/sup -/ formation by charge transfer in alkaline-earth vapors is reported. The H/sup -/ equilibrium yield in strontium vapor reaches a maximum of 50% at an energy of 250 eV/amu, which is the highest H/sup -/ yield reported to date.
Date: October 1, 1983
Creator: Schlachter, A.S. & Morgan, T.J.
System: The UNT Digital Library
Design and fabrication of a 30 second pulsed plasma generator (open access)

Design and fabrication of a 30 second pulsed plasma generator

The design and fabrication techniques for a large hybrid magnetic cusp plasma generator developed for 30 sec pulse length are described. Included are the magnetic cusp geometry features, water cooling characteristics, filament structures, and the high energy density actively cooled anode and electron dump employed.
Date: October 1, 1983
Creator: Biagi, L. A.; Ehlers, K. W.; Lietzke, A. F.; Matuk, C. A.; Maruyama, Y.; Paterson, J. A. et al.
System: The UNT Digital Library
Plastic box: a 4. pi. detector for intermediate energy heavy ion physics (open access)

Plastic box: a 4. pi. detector for intermediate energy heavy ion physics

A 4..pi.. array of plastic scintillator has been constructed and used in conjunction with high resolution solid state detectors. The array is employed principally to discriminate multinucleon transfer reactions from three-body (or more) final states. It should be useful for a broad class of experiments in which a global charged particle anticoincidence is required.
Date: October 1, 1983
Creator: Van Bibber, K.; Countryman, P.J.; Murphy, M.J.; Chan, Y.D.; Stokstad, R.G.; Tserruya, I. et al.
System: The UNT Digital Library
Si(Li) x-ray detectors with amorphous silicon passivation (open access)

Si(Li) x-ray detectors with amorphous silicon passivation

Lithium-drifted silicon (Si(Li)) detectors with thin lithium n/sup +/ contacts and amorphous silicon (..cap alpha..-Si) junction passivation are described. These detectors (7 mm thick, 9 cm/sup 2/ area) are intended for use in a six element detector array which is designed to measure trace amounts of plutonium in soil samples. Results are given showing a spectral resolution of approx. 400 eV (FWHM) for the 17.8 keV N/sub p/ L x-rays entering through either these detectors. Measurements on the effects of the fractional H/sub 2/ concentration on the electrical behavior of the ..cap alpha..-Si/Si interface are reported. The increase with time in the lithium window thickness when the detectors are stored at room temperature is discussed.
Date: October 1, 1983
Creator: Walton, J.T.; Pehl, R.H.; Wong, Y.K. & Cork, C.P.
System: The UNT Digital Library
Corrosion and oxidation of vanadium-base alloys (open access)

Corrosion and oxidation of vanadium-base alloys

The corrosion of several V-base alloys on exposure at elevated temperatures to helium environments containing hydrogen and/or water vapor are presented. These results are utilized to discuss the consequences of the selection of certain radiation-damage resistant, V-base alloys for structural materials applications in a fusion reactor.
Date: October 1, 1983
Creator: Loomis, B. A. & Wiggins, G.
System: The UNT Digital Library
Nuclear war: preliminary estimates of the climatic effects of a nuclear exchange (open access)

Nuclear war: preliminary estimates of the climatic effects of a nuclear exchange

The smoke rising from burning cities, industrial areas, and forests if such areas are attacked as part of a major nuclear exchange is projected to increase the hemispheric average atmospheric burden of highly absorbent carbonaceous material by 100 to 1000 times. As the smoke spreads from these fires, it would prevent sunlight from reaching the surface, leading to a sharp cooling of land areas over a several day period. Within a few weeks, the thick smoke would spread so as to largely cover the mid-latitudes of the Northern Hemisphere, cooling mid-continental smoke-covered areas by, perhaps, a few tens of degrees Celsius. Cooling of near coastal areas would be substantially less, since oceanic heat capacity would help to buffer temperature changes in such regions. The calculations on which these findings are based contain many assumptions, shortcomings and uncertainties that affect many aspects of the estimated response. It seems, nonetheless, quite possible that if a nuclear exchange involves attacks on a very large number of cities and industrial areas, thereby starting fires that generate as much smoke as is suggested by recent studies, substantial cooling could be expected that would last weeks to months over most continental regions of the Northern Hemisphere, …
Date: October 1, 1983
Creator: MacCracken, M.C.
System: The UNT Digital Library
Multichannel interval timer (open access)

Multichannel interval timer

A CAMAC based modular multichannel interval timer is described. The timer comprises twelve high resolution time digitizers with a common start enabling twelve independent stop inputs. Ten time ranges from 2.5 ..mu..s to 1.3 ..mu..s can be preset. Time can be read out in twelve 24-bit words either via CAMAC Crate Controller or an external FIFO register. LSB time calibration is 78.125 ps. An additional word reads out the operational status of twelve stop channels. The system consists of two modules. The analog module contains a reference clock and 13 analog time stretchers. The digital module contains counters, logic and interface circuits. The timer has an excellent differential linearity, thermal stability and crosstalk free performance.
Date: October 1, 1983
Creator: Turko, B.T.
System: The UNT Digital Library
Quantum chromodynamics in few-nucleon systems (open access)

Quantum chromodynamics in few-nucleon systems

One of the most important implications of quantum chromodynamics (QCD) is that nuclear systems and forces can be described at a fundamental level. The theory provides natural explanations for the basic features of hadronic physics: the meson and baryon spectra, quark statistics, the structure of the weak and electromagnetic currents of hadrons, the scale-invariance of hadronic interactions at short distances, and evidently, color (i.e., quark and gluon) confinement at large distances. Many different and diverse tests have confirmed the basic predictions of QCD; however, since tests of quark and gluon interactions must be done within the confines of hadrons there have been few truly quantitative checks. Nevertheless, it appears likely that QCD is the fundamental theory of hadronic and nuclear interactions in the same sense that QED gives a precise description of electrodynamic interctions. Topics discussed include exclusive processes in QCD, the deuteron in QCD, reduced nuclear amplitudes, and limitations of traditional nuclear physics. 32 references. (WHK)
Date: October 1, 1983
Creator: Brodsky, Stanley J.
System: The UNT Digital Library