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IAEA advisory group meeting on basic and applied problems of nuclear level densities (open access)

IAEA advisory group meeting on basic and applied problems of nuclear level densities

Separate entries were made in the data base for 17 of the 19 papers included. Two papers were previously included in the data base. Workshop reports are included on (1) nuclear level density theories and nuclear model reaction cross-section calculations and (2) extraction of nuclear level density information from experimental data. (WHK)
Date: June 1, 1983
Creator: Bhat, M.R. (ed.)
System: The UNT Digital Library
Magnetic switching (open access)

Magnetic switching

The paper discusses the development program in magnetic switching which was aimed at solving the rep-rate and reliability limitations of the ATA spark gaps. The end result has been a prototype physically very similar to the present Advanced Test Accelerator (ATA) pulse power unit but vastly superior in performance. This prototype, which is easily adaptable to the existing systems, has achieved a burst rep-rate of 20 kHz and an output voltage of 500 kV. A one-on-one substitution of the existing pulse power module would result in a 100 MeV accelerator. Furthermore, the high efficiency of the magnetic pulse compression stages has allowed CW operation of the prototype at one kilohertz opening up other applications for the pulse power. Performance and design details will be described.
Date: June 1, 1983
Creator: Birx, D.; Cook, E.; Hawkins, S.; Poor, S.; Reginato, L.; Schmidt, J. et al.
System: The UNT Digital Library
Biomass production and chemical cycling in a man-made geothermal wetland (open access)

Biomass production and chemical cycling in a man-made geothermal wetland

Biomass production and, to a lesser extent, chemical cycling have been evaluated in a man-made wetland created using geothermal water in southcentral Idaho. The wetland system consisted of a 0.25 ha area divided into two ponds. The upper pond contained submerged species (Egeria, pondweeds and coontail); the lower pond was planted with emergents (cattail, bulrush, and common reed). Biomass production from emergent plants in the two-year-old system was promising and compared favorably with production values reported in the literature for natural wetlands. Chemical cycling of potassium (K) was evaluated through the lower pond system. Uptake of several other constituents (F and Na) of the geothermal water by the emergent plants was observed. However, there was little difference in elemental concentrations of the system's influent and effluent, probably due to evapotranspiration of water which effectively concentrates elements in the remaining water. Twenty-one species of diatoms were identified in the geothermal wetland, and numerous species of insects were observed. The man-made wetland also created substantial habitat for wildlife. This type of system could be used as an alternative to injection of spent geothermal fluids from small-scale projects. Study results indicate that a wetland system can be developed to produce substantial quantities of …
Date: June 1, 1983
Creator: Breckenridge, Robert P.; Wheeler, Lisa R. & Ginsburg, Jeffery F.
System: The UNT Digital Library
Problems at the interface between perturbative and nonperturbative quantum chromodynamics (open access)

Problems at the interface between perturbative and nonperturbative quantum chromodynamics

Predictions based on perturbative QCD rest on three premises: (1) that hadronic interactions become weak in strength at small invariant separation; (2) that the perturbative expansion in ..cap alpha../sub s/(Q) is well-defined; and (3) factorization: all effects of collinear singularities, confinement, nonperturbative interactions, and bound state dynamics can be isolated at large momentum transfer in terms of structure functions, fragmentation functions, or in the case of exclusive processes, distribution amplitudes. The assumption that the perturbative expansion for hard scattering amplitudes converges has certainly not been demonstrated; in addition, there are serious ambiguities concerning the choice of renormalization scheme and scale choice Q/sup 2/ for the expansion in ..cap alpha../sub s/(Q/sup 2/). We will discuss a new procedure to at least partly rectify the latter problem. In the case of exclusive processes, the factorization of hadronic amplitudes at large momentum transfer in the form of distribution amplitudes convoluted with hard scattering quark-gluon subprocess amplitudes can be demonstrated systematically to all orders in ..cap alpha../sub s/(Q/sup 2/). In the case of inclusive reactions, factorization remains an ansatz; general all-orders proofs do not exist because of the complications of soft initial state interactions for hadron-induced processes; thus far factorization has only been verified …
Date: June 1, 1983
Creator: Brodsky, S. J.; Bodwin, G. T. & Lepage, G. P.
System: The UNT Digital Library
Use of ORACLE in a scientific environment (open access)

Use of ORACLE in a scientific environment

This paper discusses the use of ORACLE at the Fusion Experiments Analysis Facility (FEAF) for the laser program of the Lawrence Livermore National Laboratory. The mission of this VAX based computing facility is to aid laser program scientists and engineers develop their understanding of inertial confinement fusion target behavior. We have incorporated the ORACLE DBMS as a major part of an integrated data management and analysis environment for accomplishing this task. We discuss our use of ORACLE through all phases of data processing from raw digital forms to final physics summary data. Applications include: an information management tool for maintaining large amounts of one- and two-dimensional data, a configuration management tool for experiment setup information, and a data analysis tool for maintaining calibration and sensor response data.
Date: June 22, 1983
Creator: Carey, R. W.; Auerbach, J. M.; Lerche, R. A. & Demartini, B. J.
System: The UNT Digital Library
Nuclear design of a very-low-activation fusion reactor (open access)

Nuclear design of a very-low-activation fusion reactor

An investigation was conducted to study the nuclear design aspects of using very-low-activation materials, such as SiC, MgO, and aluminum for fusion-reactor first wall, blanket, and shield applications. In addition to the advantage of very-low radioactive inventory, it was found that the very-low-activation fusion reactor can also offer an adequate tritium-breeding ratio and substantial amount of blanket nuclear heating as a conventional-material-structured reactor does. The most-stringent design constraint found in a very-low-activation fusion reactor is the limited space available in the inboard region of a tokamak concept for shielding to protect the superconducting toroidal field coil. A reference design was developed which mitigates the constraint by adopting a removable tungsten shield design that retains the inboard dimensions and gives the same shield performance as the reference STARFIRE tokamak reactor design.
Date: June 1, 1983
Creator: Cheng, E.T. & Hopkins, G.R.
System: The UNT Digital Library
Low-cycle fatigue behavior of HT-9 alloy in a flowing-lithium environment (open access)

Low-cycle fatigue behavior of HT-9 alloy in a flowing-lithium environment

Low-cycle fatigue data have been obtained on normalized/tempered or lithium-preexposed HT-9 alloy at 755 K in flowing lithium of controlled purity. The results show that the fatigue life of this material decreases with an increase in nitrogen content in lithium. A reduction in strain rate also decreases the fatigue life in high-nitrogen lithium. However, in the range from approx. 4 x 10/sup -4/ to 4 x 10/sup -2/ s/sup -1/, the strain rate has no effect on fatigue life in lithium containing <200 wppM nitrogen. The fatigue life of the HT-9 alloy in low-nitrogen lithium is significantly greater than the fatigue life of Fe-9Cr-1Mo steel or Type 403 martensitic steel in air. Furthermore, a 4.0-Ms preexposure to low-nitrogen lithium has no influence on fatigue life. The reduction in fatigue life in high-nitrogen lithium is attributed to internal corrosive attack of the material. The specimens tested in high-nitrogen lithium show internal corrosion along grain and martensitic lathe boundaries and intergranular fracture. This behavior is not observed in specimens tested in low-nitrogen lithium. Results for a constant-load corrosion test in flowing lithium are also presented.
Date: June 1, 1983
Creator: Chopra, O. K. & Smith, D. L.
System: The UNT Digital Library
Structure of high-burnup-fuel Zircaloy cladding. [PWR; BWR] (open access)

Structure of high-burnup-fuel Zircaloy cladding. [PWR; BWR]

Zircaloy cladding from high-burnup (> 20 MWd/kg U) fuel rods in light-water reactors is characterized by a high density of irradiation-induced defects (RID), compositional changes (e.g., oxygen and hydrogen uptake) associated with in-service corrosion, and geometrical changes produced by creepdown, bowing, and irradiation-induced growth. During a reactor power transient, the cladding is subject to localized stress imposed by thermal expansion of the cracked fuel pellets and to mechanical constraints imposed by pellet-cladding friction. As part of a program to provide a better understanding of brittle-type failure of Zircaloy fuel cladding by pellet-cladding interaction (PCI) phenomenon, the stress-rupture properties and microstructural characteristics of high-burnup spent fuel cladding have been under investigation. This paper reports the results of the microstructural examinations by optical microscopy, scanning (SEM), 100-keV transmission (TEM), and 1 MeV high-voltage (HVEM) electron microscopies of the fractured spent fuel cladding with a specific empahsis on a correlation of the structural characteristics with the fracture behavior.
Date: June 1, 1983
Creator: Chung, H.M.
System: The UNT Digital Library
High-charge-state ion sources (open access)

High-charge-state ion sources

Sources of high charge state positive ions have uses in a variety of research fields. For heavy ion particle accelerators higher charge state particles give greater acceleration per gap and greater bending strength in a magnet. Thus higher energies can be obtained from circular accelerators of a given size, and linear accelerators can be designed with higher energy gain per length using higher charge state ions. In atomic physics the many atomic transitions in highly charged ions supplies a wealth of spectroscopy data. High charge state ion beams are also used for charge exchange and crossed beam experiments. High charge state ion sources are reviewed. (WHK)
Date: June 1, 1983
Creator: Clark, D. J.
System: The UNT Digital Library
Confirmation of the calculated breeding ratio for CRBRP (open access)

Confirmation of the calculated breeding ratio for CRBRP

A breeding ratio of at least 1.2 was a design goal for CRBRP. The value for the initial core (using plutonium with 11% /sup 240/Pu) calculated with ENDF/B-IV data is 1.27. Engineering mock-up studies for CRBRP were made in ZPPR-11. Analysis of ZPPR-11 using ENDF/B-IV data showed consistent underprediction of K/sub eff/ by about 1.5% and overpredictions of the /sup 238/U capture to /sup 239/Pu fission ratio (C8/F9) between 5% and 8%. These results are typical for all LMFBR critical assemblies at ANL. The following approach was used to determine the breeding ratio: sensitivity analysis of a range of fast reactor benchmarks and a fit to the experimental data by data adjustment; tests of the adjusted data against experiments in ZPPR-11; calculations for CRBRP with ENDF/B-IV data and the adjusted data to predict the breeding ratio bias; and estimates of k/sub eff/ and breeding ratio uncertainties using data sensitivities for CRBRP.
Date: June 3, 1983
Creator: Collins, P.J.; Liaw, J. & Turski, R.
System: The UNT Digital Library
Equilibrium charge states of uranium at relativistic energies (open access)

Equilibrium charge states of uranium at relativistic energies

We have measured the charge fractions of uranium ions at energies of 962 MeV/amu and 430 MeV/amu passing through various thickness targets of mylar (Z approx. = 6.6), Cu (Z = 29) and Ta (Z = 73). From these we determine the equilibrium charge state distributions.
Date: June 1, 1983
Creator: Crawford, H.; Gould, H.; Greiner, D.; Lindstrom, P. & Symons, J.
System: The UNT Digital Library
LULU analysis program (open access)

LULU analysis program

Our analysis program LULU has proven very useful in all stages of experiment analysis, from prerun detector debugging through final data reduction. It has solved our problem of having arbitrary word length events and is easy enough to use that many separate experimenters are now analyzing with LULU. The ability to use the same software for all stages of experiment analysis greatly eases the programming burden. We may even get around to making the graphics elegant someday.
Date: June 1, 1983
Creator: Crawford, H.J. & Lindstrom, P.J.
System: The UNT Digital Library
Use of fusion-welding techniques in fabrication of a superconducting-magnet thermal-shield system (open access)

Use of fusion-welding techniques in fabrication of a superconducting-magnet thermal-shield system

Success of the thermal shield system was demonstrated by the results of acceptance tests performed with the magnet and all its ancillary equipment. During these tests the thermal shield system was: (1) thermally cycled several times from 300/sup 0/K to 77/sup 0/K; (2) pressure cycled several times from 0 to 5 atmospheres; (3) operated for more than 500 hours at 77/sup 0/K and in a vacuum environment of less than 10/sup -5/ torr; (4) operated in a magnetic field up to 6.0 Telsa; (5) exposed to a rapidly collapsing magnetic field of more than 250 gauss per second; (6) drained of all LN/sub 2/ in a few minutes, without any weld failures. The successful (and relatively problem free) operation of the magnet system validates the choice of the welding processes used, as well as their execution in both shop and field environments.
Date: June 10, 1983
Creator: Dalder, E. N. C.; Berkey, J. H.; Chang, Y.; Johnson, G. L.; Lathrop, G. H.; Podesta, D. L. et al.
System: The UNT Digital Library
Subnanosecond-rise-time, low-impedance pulse generator (open access)

Subnanosecond-rise-time, low-impedance pulse generator

This paper describes a fast rise, low-impedance pulse generator that has been developed at the Lawrence Livermore National Laboratory. The design specifications of this generator are: 50-kV operating voltage, 1-ohm output impedance, subnanosecond rise time, and a 2 to 10 nanosecond pulse length. High repetition rate is not required. The design chosen is a parallel-plate, folded Blumlein generator. A tack switch is utilized for its simple construction and high performance. The primary diagnostic is a capacitive voltage divider with a B probe used to measure the current waveform.
Date: June 3, 1983
Creator: Druce, R. & Vogtlin, G.
System: The UNT Digital Library
Negative-ion sources for neutral-beam systems (open access)

Negative-ion sources for neutral-beam systems

There are three main methods now used to produce negative hydrogen ions: charge exchange, volume production, and surface production, and this paper briefly describes these three systems.
Date: June 1, 1983
Creator: Ehlers, K. W.
System: The UNT Digital Library
Radially resolved simulation of a high-gain free electron laser amplifier (open access)

Radially resolved simulation of a high-gain free electron laser amplifier

The results of a two-dimensional simulation of a high-gain free electron laser (FEL) amplifier is presented. The simulation solves the inhomogeneous paraxial wave equation. The source term is radially resolved and is obtained by tracking the interaction of the laser field with localized macroparticles.
Date: June 27, 1983
Creator: Fawley, W. M.; Prosnitz, D.; Doss, S. & Gelinas, R.
System: The UNT Digital Library
Macroscopic behavior of fast reactor fuel subjected to simulated thermal transients (open access)

Macroscopic behavior of fast reactor fuel subjected to simulated thermal transients

High-speed cinematography has been used to characterize the macroscopic behavior of irradiated and unirradiated fuel subjected to thermal transients prototypical of fast reactor transients. The results demonstrate that as the cladding melts, the fuel can disperse via spallation if the fuel contains in excess of approx. 16 ..mu..moles/gm of fission gas. Once the cladding has melted, the macroscopic behavior (time to failure and dispersive nature) was strongly influenced by the presence of volatile fission products and the heating rate.
Date: June 1, 1983
Creator: Fenske, G.R.; Emerson, J.E. & Savoie, F.E.
System: The UNT Digital Library
5. 8 GHz ophthalmic microwave applicator for treatment of choroidal melanoma (open access)

5. 8 GHz ophthalmic microwave applicator for treatment of choroidal melanoma

We report on the use of a 5.8 GHz microwave applicator to treat choroidal melanoma (Greene) in rabbits. The physical requirements needed to treat these intraocular tumors are quite different from those encountered elsewhere in the body. From a trans-scleral approach the penetration needed is minimal (5 to 10 mm.). The fibrous sclera is the only structure between the heat source and the tumor. The sclera has a relatively low water content when compared to tumor. This fact in addition to the frequency dependent interactions of tissue and electromagnetic radiation, results in an advantage to the use of the 5.8 GHz microwave device in treating intraocular malignancies.
Date: June 1983
Creator: Finger, Paul T.; Packer, Samuel; Svitra, Paul; Paglione, Robert W.; Albert, Daniel M. & Chess, Jeremy
System: The UNT Digital Library
A Measurement of the Cosmic Background Radiation Temperature at3.0 cm (open access)

A Measurement of the Cosmic Background Radiation Temperature at3.0 cm

We describe a measurement of the cosmic background radiation temperature at a wavelength of 3.0 cm. The experiment was made in conjunction with measurements at four other wavelengths in an effort to measure the long wavelength spectrum to high accuracy. The result at 3 cm, T{sub CBR} = 2.91 {+-} 0.19 K, is in good agreement with the values at neighboring wavelengths, and consistent with previous results.
Date: June 1, 1983
Creator: Friedman, S. D.; Smoot, G. F.; De Amici, G. & Witebsky, C.
System: The UNT Digital Library
Accelerator breeders: will they replace liquid metal fast breeders (open access)

Accelerator breeders: will they replace liquid metal fast breeders

Investigation of accelerator breeders at Brookhaven National Laboratory indicate that the AB-LWR fuel cycle is economically competitive with the LMFBR fuel cycle. The same can be said about the accelerator breeder-High Temperature Gas Reactor symbiosis. This system appears to be very competitive with the added real advantage of superior safety and proliferation resistance. This discussion would be incomplete if the real competitor to accelerator breeding was not mentioned, namely Fusion Hybrid Breeding (FHB). Fusion Hybrid Breeding is a nearer option than pure fusion, as the breakeven Q value requirements are much more modest. Fusion Hybrid Breeding, if successful and practical, has the potential for highly efficient fissile fuel breeding, leading to cheaper fuel. The system, however, has yet to be demonstrated scientifically and to be shown commercially feasible. This is in contrast with the AB system which is an extension of proven, state-of-the-art technology with implementation possible within twenty years. 25 references, 4 figures, 5 tables.
Date: June 1, 1983
Creator: Grand, P.; Powell, J.R.; Steinberg, M. & Takahashi, H.
System: The UNT Digital Library
Near-Death Experiences in a Southern California Population (open access)

Near-Death Experiences in a Southern California Population

This paper discusses "41 persons who were near death or clinically dead as the result of an accident, illness, or suicide attempt are presented. Respondents reported a total of 50 near-death experiences (NDEs) of which 33 were rated (using K. Ring's Weighted Core Experience Index) as having been deep, 10 as moderate, and 7 as non-experiences" (abstract).
Date: June 1983
Creator: Green, J. Timothy
System: The UNT Digital Library
Multiple Mind/Body Perspectives and the Out-of-Body Experience (open access)

Multiple Mind/Body Perspectives and the Out-of-Body Experience

"This study reviews and analyzes evidence for a rare but persistently reported facet of out-of-body experience (OBE)/near-death experience (NDE) phenomenology designated the "multiple-body/split-consciousness" effect. Those who experience this effect describe the sensation of possessing and in some instances simultaneously occupying a multiple number of "bodies" at varying locations, sometimes in conjunction with the sense of being disembodied" (abstract). The paper also analyzes this phenomenon from a neurological perspective and the mathematical branch called topology.
Date: June 1983
Creator: Greene, F. Gordon
System: The UNT Digital Library
Jung, Parapsychology, and the Near-Death Experience: Toward a Transpersonal Paradigm (open access)

Jung, Parapsychology, and the Near-Death Experience: Toward a Transpersonal Paradigm

This paper discusses near-death experiences (NDEs) under the framework of the Jungian theory of archetypes. "NDEs are looked at as evidence for the activation of a unique archetype associated with rebirth experience, designated the archetype of death and enlightenment (ADE). The general function of the ADE is outlined, and evidence for the psychic manifestations of it is reviewed" (abstract).
Date: June 1983
Creator: Grosso, Michael
System: The UNT Digital Library
Methods for deconvoluting and interpreting complex gamma- and x-ray spectral regions (open access)

Methods for deconvoluting and interpreting complex gamma- and x-ray spectral regions

Germanium and silicon detectors are now widely used for the detection and measurement of x and gamma radiation. However, some analysis situations and spectral regions have heretofore been too complex to deconvolute and interpret by techniques in general use. One example is the L x-ray spectrum of an element taken with a Ge or Si detector. This paper describes some new tools and methods that were developed to analyze complex spectral regions; they are illustrated with examples.
Date: June 1, 1983
Creator: Gunnink, R.
System: The UNT Digital Library