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Signature Inversion in Odd-odd Nuclei

Description: Trends in the energy staggering of the {pi}h{sub 11/2}{nu}i{sub 13/2} and {pi}h{sub 11/2} {nu}h{sub 11/2} bands in the mass 160 and 130 regions, respectively, have been investigated in order to better understand the origin of signature inversion. While the A {approx} 160 nuclei behave in a consistent manner, a more complicated scenario is observed in the mass 130 region. As a result of our experiments on the lightest Pr nuclei, the systematics of these Z = 59 nuclei have been extended, which aids in the understanding of the latter region. Triaxial deformation, a pn interaction, and quadrupole pairing are considered as possible contributors to this effect. As all the chiral-twin bands that are known have signature inversion in the favored band, a possible link between the two phenomena should be considered.
Date: September 10, 2001
Creator: Riedinger, L.L.
Partner: UNT Libraries Government Documents Department
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Shell-model Monte Carlo calculations near N = Z

Description: The pairing and structure of nuclei near N = Z is described in the framework of shell-model Monte Carlo (SMMC) calculations. Principal results include the enhancement of J=0, T=1 proton-neutron pairing at N=Z nuclei, and the marked difference of thermal properties between even-even and odd-odd N=Z nuclei. Additionally I will present a study of the rotational properties for the T=1 (ground state), and T=0 band mixing seen in {sup 74}Rb.
Date: October 1, 1996
Creator: Dean, D.J.
Partner: UNT Libraries Government Documents Department
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Nuclear structure considerations for gamma-ray lasers

Description: Presented are initial results in our investigation of the nuclear physics issues of gamma-ray lasers. These include the questions of what is known from existing experimental data, where does one optimally search for nuclei displaying simultaneously both closely lying levels and nuclear isomerism, and which theoretical models does one employ for systematic searches for candidate nuclei and for calculation of detailed candidate level properties.
Date: January 1, 1985
Creator: Strottman, D.; Arthur, E. D. & Madland, D. G.
Partner: UNT Libraries Government Documents Department
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Survey of odd-odd deformed nuclear spectroscopy

Description: In this paper, we survey the current experimental data that support assignment of rotational bands in odd-odd deformed nuclear in the rare earth and actinide regions. We present the results of a new study of {sup 170}Mt nuclear structure. In a comparing experimental and calculated Gallagher-Moszkowski matrix elements for rare earth-region nuclei, we have developed a new approach to the systematics of these matrix elements.
Date: September 14, 1993
Creator: Hoff, R. W.
Partner: UNT Libraries Government Documents Department
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Shell-model Monte Carlo studies of nuclei

Description: The pair content and structure of nuclei near N = Z are described in the frwnework of shell-model Monte Carlo (SMMC) calculations. Results include the enhancement of J=0 T=1 proton-neutron pairing at N=Z nuclei, and the maxked difference of thermal properties between even-even and odd-odd N=Z nuclei. Additionally, a study of the rotational properties of the T=1 (ground state), and T=0 band mixing seen in {sup 74}Rb is presented.
Date: February 1, 1997
Creator: Dean, D.J.
Partner: UNT Libraries Government Documents Department
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Nuclear structure models: Applications and development. Progress report, November 1, 1991--June 30, 1992

Description: This report discusses the following topics: Studies of superdeformed States; Signature Inversion in Odd-Odd Nuclei: A fingerprint of Triaxiality; Signature Inversion in {sup 120}Cs - Evidence for a Residual p-n Interaction; Signatures of {gamma} Deformation in Nuclei and an Application to {sup 125}Xe; Nuclear Spins and Moments: Fundamental Structural Information; and Electromagnetic Properties of {sup 181}Ir: Evidence of {beta} Stretching.
Date: July 1, 1992
Creator: Semmes, P. B.
Partner: UNT Libraries Government Documents Department
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Infrared Spectroscopy and Hydrogen Isotope Geochemistry of Hydrous Silicate Glasses

Description: The focus of this project is the combined appication of infrared spectroscopy and stable isotope geochemistry to the study of hydrogen-bearing species dissolved in silicate melts and glasses. We are conducting laboratory experiments aimed at determining the fractionation of D and H between melt species (OH and H{sub 2}O) and hydrous vapor and the diffusivities of these species in glasses and melts. Knowledge of these parameters is critical to understanding the behavior of hydrogen isotopes during igneous processes and hydrothermal processes. These results also could be valuable in application of glass technology to development of nuclear waste disposal strategies.
Date: January 1, 1992
Creator: Epstein, S. & Stolper, E.
Partner: UNT Libraries Government Documents Department
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Study of the prospects for heavy water production via laser isotope separation. Final report, 1 April--30 September 1976

Description: The rationale for ''cheap'' heavy water is discussed with emphasis on the economic, safety, and arms control implications of the widespread adoption of pressure-tube, heavy water moderated and cooled CANDU reactors, and variations thereof. Three classes of vibrational-photochemical laser processes are considered in detail, i.e., hydrogen halide-unsaturated hydrocarbon addition reactions, isotopically selective photoadsorption and photodesorption, and selective two-step molecular dissociation. General remarks are made concerning the economic viability of these techniques vis a vis hydrogen sulfide/water chemical exchange (the GS process).
Date: October 1, 1976
Creator: Miller, M. M.
Partner: UNT Libraries Government Documents Department
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Stereoselective disposition of R-(-)- and S-(+)-methadone in man

Description: Deuterium-labeled methadone has been used to study the urinary excretion of racemic methadone, R-(-)- and S-(+)-methadone in adult maintenance patients. In three cases studied, the pharmacologically active enantiomer, R-(-)-methadone, had a significantly longer elimination half-life (51.7 to 61.8 hours) than did the inactive S-(+)-methadone (31.8 to 37.0 hours). The ratio of drug elimination half-lives, R-(-)-/S-(+)-, ranged between 1.39 and 1.94.
Date: January 1, 1978
Creator: Hachey, D. L.; Kreek, M. J. & Klein, P. D.
Partner: UNT Libraries Government Documents Department
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Optimization of the fission--fusion hybrid concept

Description: One of the potentially attractive applications of controlled thermonuclear fusion is the fission--fusion hybrid concept. In this report we examine the possible role of the hybrid as a fissile fuel producer. We parameterize the advantages of the concept in terms of the performance of the fusion device and the breeding blanket and discuss some of the more troublesome features of existing design studies. The analysis suggests that hybrids based on deuterium--tritium (D--T) fusion devices are unlikely to be economically attractive and that they present formidable blanket technology problems. We suggest an alternative approach based on a semicatalyzed deuterium--deuterium (D--D) fusion reactor and a molten salt blanket. This concept is shown to emphasize the desirable features of the hybrid, to have considerably greater economic potential, and to mitigate many of the disadvantages of D--T-based systems.
Date: April 1, 1979
Creator: Saltmarsh, M. J.; Grimes, W. R. & Santoro, R. T.
Partner: UNT Libraries Government Documents Department
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Pulsed reflex ion source studies

Description: Parametric studies of demountable versions of the pulsed ion source used in Controlatron and Zetatron neutron tubes were carried out. The goal of these experiments, a continuation of earlier work by Bacon and O'Hagan, was to investigate the deuteron beam intensity as a function of source geometry, electrode materials, operating conditions and pulse length. Geometric variations produced only modest changes in the ion beam intensity; the most sensitive parameter was the length of the secondary cathode. There is some evidence that the addition of oxygen either in the gas feed or using alumina on the cathode surfaces can increase the atomic ion fraction. The lowest reliable operating source pressure was approximately 1.33 Pa. The longest pulse length was about 1.2 ms. Difficulties in measuring the ion currents are discussed and suggestions for future experiments are briefly outlined.
Date: November 1, 1980
Creator: Bickes, R. W., Jr.; O&#x27 & Hagan, J. B.
Partner: UNT Libraries Government Documents Department
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Advanced-fuel reversed-field pinch reactor (RFPR)

Description: The utilization of deuterium-based fuels offers the potential advantages of greater flexibility in blanket design, significantly reduced tritium inventory, potential reduction in radioactivity level, and utilization of an inexhaustible fuel supply. The conventional DT-fueled Reversed-Field Pinch Reactor (RFPR) designs are reviewed, and the recent extension of these devices to advanced-fuel (catalyzed-DD) operation is presented. Attractive and economically competitive DD/RFPR systems are identified having power densities and plasma parameters comparable to the DT systems. Converting an RFP reactor from DT to DD primarily requires increasing the magnetic field levels a factor of two, still requiring only modest magnet coil fields (less than or equal to 4 T). When compared to the mainline tokamak, the unique advantages of the RFP (e.g., high beta, low fields at the coils, high ohmic-heating power densities, unrestricted aspect ratio) are particularly apparent for the utilization of advanced fuels.
Date: October 1, 1981
Creator: Hagenson, Randy L. & Krakowski, Robert A.
Partner: UNT Libraries Government Documents Department
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Performance of a developmental 120-keV, 10-A deuterium (14-A hydrogen) neutral beam system

Description: We have recently operated the LBL 120-keV neutral beam test facility on deuterium. This facility consists of a large (170,000 l) vacuum system, a plasma source, a multiple-aperture electrostatic accelerator structure, an ion sweep magnet, ion and neutral beam dumps, and a computer diagnostic and control system. The total length of the beamline is about 8.5m. Operation of this test facility on deuterium has produced beams with an energy of 120 keV, a total (ion plus neutral) beam current of 10 A, and a pulse length of 0.5 sec. The beam profile at the location of the dump is bi-gaussian, with 1/e halfwidths of about 1.28 and 0.42 degrees. Deuterium operation has been very limited because of the high neutron production rate (about 10/sup 11/ sec/sup -1/ when the beam is on) and the lack of radiation shielding around the facility.
Date: October 1, 1977
Creator: Berkner, K. H.; Cooper, W. S.; Ehlers, K. W. & Pyle, R. V.
Partner: UNT Libraries Government Documents Department
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Theory of double-quantum coherence and high resolution deuterium NMR in solids

Description: When a spin-1 with quadrupole interaction ..omega../sub Q/ is irradiated near resonance ..omega../sub 0/(..omega../sub 0/-..omega.. = ..delta omega..) with an rf field ..omega../sub 1/ such that ..omega../sub 1/ is much less than ..omega../sub Q/ the density matrix essentially evolves in a three dimensional frame of reference defined by the operators I/sub z,1/ = /sup 1///sub 2/I/sub z/, I/sub z,2/ = /sup 1///sub 2/ (I/sub x/I/sub y/ + I/sub y/I/sub x/), I/sub z,3/ = -/sup 1///sub 2/ (I/sup 2//sub x/ - I/sup 2//sub y/). In this frame, which we term ''z-space'' or the ''double quantum frame'' the effective rf intensity is ..omega../sup 2//sub I//..omega../sub Q/ and the effective resonance offset is 2..delta omega... We demonstrate in this paper that an rf phase shift of phi corresponds to a 2phi shift of ..omega../sup 2//sub I//..omega../sub Q/ in the double quantum frame. This is used to perform double quantum phase reversal and double quantum spin locking. Applications to high resolution deuterium nmr in solids are also illustrated.
Date: August 1, 1976
Creator: Vega, S. & Pines, A.
Partner: UNT Libraries Government Documents Department
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Critical impurity concentrations for ignition of catalyzed-deuterium fusion plasmas

Description: The maximum concentrations f/sub zc/ of various impurity species that permit ignition of catalyzed-deuterium fusion plasmas have been calculated. If cyclotron radiation is negligible, the values of f/sub zc/ at 35 keV, where the fusion power density is maximum, are approximately one-fifth of the values allowed for D-T ignited plasmas at 14 keV. For any impurity species, the allowed f/sub zc/ decreases nearly linearly with increasing cyclotron radiation loss.
Date: September 1, 1977
Creator: Jensen, R. V.; Jassby, D. L. & Post, D. E.
Partner: UNT Libraries Government Documents Department
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Thermotransport of hydrogen and deuterium in vanadium, niobium and tantalum alloys

Description: Heats of transport have been determined for thermotransport of hydrogen and deuterium in pure vanadium, niobium and tantalum; in vanadium alloyed with either niobium, titanium or chromium; and in niobium-tantalum alloys. In all cases, thermotransport was toward colder regions and was significantly greater for deuterium than for hydrogen. A mass spectrometric technique was used to simultaneously measure heats of transport for hydrogen and deuterium in a single specimen containing both isotopes. This technique greatly increased the precision with which isotope effects in the heat of transport could be measured. The predominant effect of alloying was to dramatically increase thermotransport; however, thermotransport decreased as niobium was added to tantalum.
Date: October 1, 1981
Creator: Smith, M.F.
Partner: UNT Libraries Government Documents Department
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Boson Fermion Symmetries and Dynamical Supersymmetries for Odd-Odd Nuclei

Description: Odd-odd nuclei are modeled by the application of symmetries and supersymmetries in IBM/IBFM. Odd-odd nuclei are described as a mixed system if bosons and fermions by a Hamiltonian consisting of three contributions: the IBM Hamiltonian, a one-fermion and fermion-fermion interaction terms, and a boson-fermion interaction term. 23 refs., 2 figs., (WRF)
Date: January 1, 1985
Creator: Balantekin, A. B.; Huebsch, T. & Paar, V.
Partner: UNT Libraries Government Documents Department
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Development of advanced concepts for improved heavy water production technology. I. Quarterly progress report, October 1, 1976--December 31, 1976

Description: Three strongly differing processes for deuterium isotope separation continued under development during the reporting period which may lead to improved heavy water production technologies. Compound characterization continued and promising alloys were evaluated for rare-earth-transition metal hydrides suitable for chromatographic hydrogen isotope separation. Equilibrium pressure curves for hydrogen and deuterium over these compounds were measured; the single-step deuterium enrichment ratios of 30% were observed for the most promising compounds. Spectroscopic studies suggested that deuterium halide-olefin addition reactions accelerated by IR lasers can be verified by Nd-YAG laser excitations of HBr and DBr overtone bands. Compounds suitable for CO/sub 2/ laser multiphoton deuterium-selective dissociation were determined. The most promising compounds have dissociation barriers of less than 2 eV and extremely high frequency factors, which should permit high quantum efficiencies to be attainable.
Date: January 1, 1977
Creator: Marling, J. B.; Aldridge, F. T. & Wood, L. L.
Partner: UNT Libraries Government Documents Department
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Simultaneous measurement in fluid n-D/sub 2/ of P, V, T and sound velocity to 20 kbar. [T= 75 to 300 K]

Description: The molar volume and ultrasonic velocity of fluid n-D/sub 2/ as a function of pressure at constant temperature were measured simultaneously in a piston--cylinder apparatus over the range 75 less than or equal to T less than or equal to 300/sup 0/K and 2 less than P less than 20 kbar. A total of 1340 data sets along 33 isotherms were obtained with an average deviation of 0.4 percent both in volume and ultrasonic velocity. These data are being used to obtain an equation of state for deuterium. Comparisons with earlier hydrogen data show that the D/sub 2/ molar volumes are about 2 percent less than the H/sub 2/ molar volumes and that the sound velocity in D/sub 2/ is about 1/root times the sound velocity in H/sub 2/ at the same pressure and temperature. The sound velocity differences are much larger than were measured between D/sub 2/ and H/sub 2/ in solid and liquid phases. These data represent the first comprehensive high-pressure study of the properties of fluid deuterium, a material that is important in energy research. 5 figures.
Date: January 1, 1977
Creator: Liebenberg, D. H.; Mills, R. L. & Bronson, J. C.
Partner: UNT Libraries Government Documents Department
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Utilization of the catalyzed-DD fuel cycle in reversed-field pinch reactors (RFPRs)

Description: The utilization of deuterium-based fuels offers the potential advantages of greater flexibility in blanket design, significantly reduced tritium inventory, potential reduction in radioactivity level, and utilization of an inexhaustible fuel supply. The extension of the conventional DT-fueled Reversed-Field Pinch Reactor (RFPR) designs to advanced-fuel (catalyzed-DD) operation has recently been reported. Attractive and economically competitive DD/RFPR systems are identified having power densities and plasma parameters comparable to the DT systems. These designs are compared to other fusion reactor designs.
Date: January 1, 1981
Creator: Hagenson, R. L. & Krakowski, R. A.
Partner: UNT Libraries Government Documents Department
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Development of an ion source for long-pulse (30-s) neutral beam injection

Description: This paper describes the development of a long-pulse positive ion source that has been designed to provide high brightness deuterium beams (divergence approx. = 0.25/sup 0/ rms, current density approx. = 0.15 A cm/sup -2/) of 40 to 45 A, at a beam energy of 80 keV, for pulse lengths up to 30 s. The design and construction of the ion source components are described with particular emphasis placed on the long-pulse cathode assembly and ion accelerator.
Date: January 1, 1982
Creator: Menon, M. M.; Barber, G. C.; Blue, C. W.; Dagenhart, W. K.; Gardner, W. L.; Haselton, H. H. et al.
Partner: UNT Libraries Government Documents Department
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Preionization studies in ZT-40M

Description: A study of preionization techniques has been performed in ZT-40M at Los Alamos National Laboratory. The results of this study and the techniques routinely utilized to preionize the plasma in this device are presented. A simple theoretical model involving drift motion of the electrons in the inhomogeneous toroidal field B/sub phi/ present during breakdown is examined. This model is shown to offer a conceptual explanation for the breakdown limits in ZT-40M. This simple theory appears to indicate that the preionization system produces photoelectrons locally at the wall as opposed to acting as a volume source of electrons.
Date: February 1, 1982
Creator: Watt, R. G. & Downing, J. N.
Partner: UNT Libraries Government Documents Department
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Calibrations of a tritium extraction facility

Description: A tritium extraction facility has been built for the purpose of measuring the absolute tritium concentration in neutron-irradiated lithium metal samples. Two independent calibration procedures have been used to determine what fraction, if any, of tritium is lost during the extraction process. The first procedure compares independently measured /sup 4/He and /sup 3/H concentrations from the /sup 6/Li(n,..cap alpha..)T reaction. The second procedure compared measured /sup 6/Li(n,..cap alpha..)T//sup 197/Au (n,..gamma..)/sup 198/Au thermal neutron reaction rate ratios with those obtained from Monte Carlo calculations using well-known cross sections. Both calibration methods show that within experimental errors (approx. 1.5%) no tritium is lost during the extraction process.
Date: January 1, 1983
Creator: Bretscher, M. M.; Oliver, B. M. & Farrar IV, H.
Partner: UNT Libraries Government Documents Department
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