Reaction cross-section calculations using new experimental and theoretical level structure data for deformed nuclei (open access)

Reaction cross-section calculations using new experimental and theoretical level structure data for deformed nuclei

A technique for modeling level structures of odd-odd nuclei has been used to construct sets of discrete states with energies in the range 0 to 1.5 MeV for several nuclei in the rare-earth and actinide regions. The accuracy of the modeling technique was determined by comparison with experimental data. Examination was made of what effect the use of these new, more complete sets of discrete states has on the calculation of level densities, total reaction cross sections, and isomer ratios. 9 refs.
Date: May 1, 1985
Creator: Hoff, R. W.; Gardner, D. G. & Gardner, M. A.
System: The UNT Digital Library
Difficulties with inferring neutron cross sections from charged-particle reactions (open access)

Difficulties with inferring neutron cross sections from charged-particle reactions

We have investigated problems associated with inferring cross sections for neutron reactions on unstable nuclei in the mass-90 region from charged-particle reactions on nearby stable targets. We conclude that effects due to precompound evaporation, isospin, and multiple reaction paths severely limit the circumstances under which charged-particle studies may be directly and easily converted to neutron cross sections of useful accuracy. 4 refs., 2 figs.
Date: May 7, 1985
Creator: Gardner, D. G. & Gardner, M. A.
System: The UNT Digital Library
Importance of level structure in nuclear reaction cross-section calculations. Revision 1 (open access)

Importance of level structure in nuclear reaction cross-section calculations. Revision 1

It is shown that level-density expressions cannot adequately represent or substitute for level structure information when making calculations of the Hauser-Feshbach type for cross sections or isomer-ratios for nuclei in the first few MeV above their ground state. It is stated that such discrete level information should include both experimentally confirmed and theoretically predicted levels. The utility of discrete level information to optimize level density calculations, to compute isomer ratios, in deriving dipole strength functions, and in the analysis of primary gamma ray spectra is emphasized, especially for nuclei far from the line of stability. 29 refs., 12 figs., 6 tabs. (DWL)
Date: November 7, 1985
Creator: Gardner, M. A. & Gardner, D. G.
System: The UNT Digital Library
Calculational tools for the evaluation of nuclear cross-section and spectra data (open access)

Calculational tools for the evaluation of nuclear cross-section and spectra data

A technique based on discrete energy levels rather than energy level densities is presented for nuclear reaction calculations. The validity of the technique is demonstrated via theoretical and experimental agreement for cross sections, isomer-ratios and gamma-ray strength functions. 50 refs., 7 figs. (WRF)
Date: May 7, 1985
Creator: Gardner, M.A.
System: The UNT Digital Library
History and results of VC-1, the first CSDP corehole in Valles caldera, New Mexico (open access)

History and results of VC-1, the first CSDP corehole in Valles caldera, New Mexico

Valles Caldera No. 1 (VC-1) is the first Continental Scientific Drilling Program (CSDP) corehole drilled in the Valles caldera and the first continuously cored hole in the caldera region. The objectives of VC-1 were to penetrate a hydrothermal outflow plume near its source, to obtain structural and stratigraphic information near the intersection of the ring-fracture zone and the pre-caldera Jemez fault zone, and to core the youngest volcanic unit inside the caldera (Banco Bonito obsidian, 0.13 Ma). VC-1 penetrates 298 m of moat volcanics and caldera-fill ignimbrites, 35 m of pre-caldera volcaniclastic breccia, and 523 m of Paleozoic carbonates, sandstones and shales, with over 95% core recovery. Hydrothermal alterations are concentrated in sheared, brecciated and fractured zones from the volcaniclastic breccia to total depth with both the intensity and rank of alterations increasing with depth. Alterations consist primarily of clays, calcite, pyrite, quartz, and chlorite, but chalcopyrite has been identified as high as 518 m and molybdenite has been identified in a fractured zone at 847 m. Thermal aquifers were penetrated at various intervals from about 510 m on down. 11 refs., 5 figs.
Date: January 1, 1985
Creator: Goff, F.; Rowley, J.; Gardner, J.N.; Hawkins, W.; Goff, S.; Pisto, L. et al.
System: The UNT Digital Library
Oak Ridge rf test facility (open access)

Oak Ridge rf test facility

The ORNL RF Test Facility is to provide a national facility for the testing and evaluation of steady state, high-power (approx.1.0-MW) Ion Cyclotron Resonance Heating (ICRH) systems and components. The facility configuration consists of a vacuum vessel and two fully tested superconducting development magnets from the EBT-P program, arranged as a simple mirror of mirror ratio 4.8. The axial centerline distance between magnet throat centers is 112 cm. The vacuum vessel cavity has a large port (74 by 163 cm) and a test volume adequate for testing prototypic launchers for DIII-D and TFTR. The magnets are capable of generating a steady state field of approx.3 T on axis in the magnet throats. Steady state plasmas are generated in the facility by cyclotron resonance breakdown using a dedicated 200-kW, 28-GHz gyrotron. Rf sources are available covering a frequency range of 2 to 200 MHz at 1.5 kW and 3 to 18 MHz at 200 kW with several sources at intermediate parameters. Available in July 1986 will be a >1.0-MW, cw source spanning 40 to 80 MHz. The report consists of nine viewgraphs.
Date: January 1, 1985
Creator: Gardner, W.L.; Hoffman, D.J.; McCurdy, H.C.; McManamy, T.J.; Moeller, J.A. & Ryan, P.M.
System: The UNT Digital Library
Oak Ridge rf Test Facility (open access)

Oak Ridge rf Test Facility

The rf Test Facility (RFTF) of Oak Ridge National Laboratory (ORNL) provides a national facility for the testing and evaluation of steady-state, high-power (approx.1.0-MW) ion cyclotron resonance heating (ICRH) systems and components. The facility consists of a vacuum vessel and two fully tested superconducting development magnets from the ELMO Bumpy Torus Proof-of-Principle (EBT-P) program. These are arranged as a simple mirror with a mirror ratio of 4.8. The axial centerline distance between magnet throat centers is 112 cm. The vacuum vessel cavity has a large port (74 by 163 cm) and a test volume adequate for testing prototypic launchers for Doublet III-D (DIII-D), Tore Supra, and the Tokamak Fusion Test Reactor (TFTR). Attached to the internal vessel walls are water-cooled panels for removing the injected rf power. The magnets are capable of generating a steady-state field of approx.3 T on axis in the magnet throats. Steady-state plasmas are generated in the facility by cyclotron resonance breakdown using a dedicated 200-kW, 28-GHz gyrotron. Available rf sources cover a frequency range of 2 to 200 MHz at 1.5 kW and 3 to 18 MHz at 200 kW, with several sources at intermediate parameters. Available in July 1986 will be a >1.0-MW, cw …
Date: January 1, 1985
Creator: Gardner, W.L.; Hoffman, D.J.; McCurdy, H.C.; McManamy, T.J.; Moeller, J.A. & Ryan, P.M.
System: The UNT Digital Library
ORNL facilities for testing first-wall components (open access)

ORNL facilities for testing first-wall components

Future long-impulse magnetic fusion devices will have operating characteristics similar to those described in the design studies of the Tokamak Fusion Core Experiment (TFCX), the Fusion Engineering Device (FED), and the International Tokamak Reactor (INTOR). Their first-wall components (pumped limiters, divertor plates, and rf waveguide launchers with Faraday shields) will be subjected to intense bombardment by energetic particles exhausted from the plasma, including fusion products. These particles are expected to have particle energies of approx.100 eV, particle fluxes of approx.10/sup 18/ cm/sup -2/.s/sup -1/, and heat fluxes of approx.1 kW/cm/sup 2/ CW to approx.100 kW/cm/sup 2/ transient. No components are available to simultaneously handle these particle and heat fluxes, survive the resulting sputtering erosion, and remove exhaust gas without degrading plasma quality. Critical issues for research and development of first-wall components have been identified in the INTOR Activity. Test facilities are needed to qualify candidate materials and develop components. At Oak Ridge National Laboratory (ORNL), existing neutral beam and wave heating test facilities can be modified to simulate first-wall environments with heat fluxes up to 30 kW/cm/sup 2/, particle fluxes of approx.10/sup 18/ cm/sup -2/.s/sup -1/, and pulse lengths up to 30 s, within test volumes up to approx.100 L. …
Date: January 1, 1985
Creator: Tsai, C.C.; Becraft, W.R.; Gardner, W.L.; Haselton, H.H.; Hoffman, D.J.; Menon, M.M. et al.
System: The UNT Digital Library
Alpha particle diagnostic beam line system to generate an intense Li/sup 0/ beam with an ORNL SITEX source (open access)

Alpha particle diagnostic beam line system to generate an intense Li/sup 0/ beam with an ORNL SITEX source

The Oak Ridge National Laboratory (ORNL) SITEX (Surface Ionization with Transverse Extraction) negative ion source utilizes a 100-V/20-A reflex arc discharge in a 1300-gauss magnetic field to generate Cs+ ions and H+ or D+ ions, depending on the beam required. A shaped molybdenum plate is placed directly behind the arc column. Cesium coverage on this plate is used to minimize the surface work function, which requires two-thirds of a monolayer coverage. Cesium coverage ia adjusted both by cesium flow control into the arc discharge chamber and by temperature control of the converter using gaseous-helium cooling channels in the converter plate. Normal converter operational temperatures are 300/sup 0/ to 500/sup 0/C H/sup -//D/sup -/ beams are generated at the biased converter surface (-150 V with respect to the anode) by Cs/sup +/ sputtering of absorbed hydrogen or deuterium and by the reflection-conversion mechanism of H/sup +//D/sup +/ ions which strike the converter surface at 150 eV. The negative ions are accelerated through the 150-V plasma sheath at the converter surface and are focused by the converter geometry and magnetic field so as to pass through the exit aperture with minimum angular divergence. The ion optics of the SITEX accelerator has been …
Date: January 1, 1985
Creator: Dagenhart, W. K.; Stirling, W. L.; Tsai, C. C. & Whealton, J. H.
System: The UNT Digital Library
Commissioning the polarized beam in the AGS (open access)

Commissioning the polarized beam in the AGS

After the successful operation of a high energy polarized proton beam at the Argonne Laboratory Zero Gradient Synchrotron (ZGS) was terminated, plans were made to commission such a beam at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). On February 23, 1984, 2 ..mu..A of polarized H/sup -/ was accelerated through the Linac to 200 MeV with a polarization of about 65%. 1 ..mu..A was injected into the AGS and acceleration attempts began. Several relatively short runs were then made during the next three months. Dedicated commissioning began in early June, and on June 26 the AGS polarized beam reached 13.8 GeV/c to exceed the previous ZGS peak momentum of 12.75 GeV/c. Commissioning continued to the point where 10/sup 10/ polarized protons were accelerated to 16.5 GeV/c with 40% polarization. Then, two experiments had a short polarized proton run. We plan to continue commissioning efforts in the fall of this year to reach higher energy, higher intensity, and higher polarization levels. We present a brief description of the facility and of the methods used for preserving the polarization of the accelerating beam.
Date: January 1, 1985
Creator: Ratner, L. G.; Brown, H.; Chiang, I. H.; Courant, E.; Gardner, C.; Lazarus, D. et al.
System: The UNT Digital Library
Experimental level-structure determination in odd-odd actinide nuclei (open access)

Experimental level-structure determination in odd-odd actinide nuclei

The status of experimental determination of level structure in odd-odd actinide nuclei is reviewed. A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei is applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation are derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings are used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Applications of this modeling technique are discussed.
Date: April 4, 1985
Creator: Hoff, R.W.
System: The UNT Digital Library
Calibration of a monochromator/spectrometer system for the measurement of photoelectron angular distributions and branching ratios (open access)

Calibration of a monochromator/spectrometer system for the measurement of photoelectron angular distributions and branching ratios

We describe the techniques used in calibrating a monochromator/spectrometer system for gas-phase photoelectron angular distribution and branching ratio measurements. We report a self-consistent set of values for the Ne 2p, Ar 3p, Kr 4p/sub 3/2/ and 4p/sub 1/2/, and Xe 5p/sub 3/2/ and 5p/sub 1/2/ photoelectron asymmetry parameters and for the Kr 4p/sub 3/2/:4p/sub 1/2/ and Xe 5p/sub 3/2/:5p/sub 1/2/ branching ratios for the energy regions from threshold to approximately 15 iV. 22 refs., 7 figs.
Date: January 1, 1985
Creator: Southworth, S. H.; Parr, A. C.; Hardis, J. E.; Dehmer, J. L. & Holland, D. M. P.
System: The UNT Digital Library
Management of National Nuclear Power Programs for assured safety (open access)

Management of National Nuclear Power Programs for assured safety

Topics discussed in this report include: nuclear utility organization; before the Florida Public Service Commission in re: St. Lucie Unit No. 2 cost recovery; nuclear reliability improvement and safety operations; nuclear utility management; training of nuclear facility personnel; US experience in key areas of nuclear safety; the US Nuclear Regulatory Commission - function and process; regulatory considerations of the risk of nuclear power plants; overview of the processes of reliability and risk management; management significance of risk analysis; international and domestic institutional issues for peaceful nuclear uses; the role of the Institute of Nuclear Power Operations (INPO); and nuclear safety activities of the International Atomic Energy Agency (IAEA).
Date: January 1, 1985
Creator: Connolly, T.J. (ed.)
System: The UNT Digital Library
Proceedings of the Workshop on Some Aspects of Autoionization in Atoms and Small Molecules (open access)

Proceedings of the Workshop on Some Aspects of Autoionization in Atoms and Small Molecules

Do we really understand the phenomenon of autoionization in atoms sufficiently well to consider it a ''mature'' topic. Can we generalize our understanding to predict behavior in systems not yet studied. Can we extract physical understanding from the encouraging results of the ''many-body calculations''. Or must we still try to understand one atom at a time. Molecular autoionization is clearly more difficult. Not only must we content with ''vibrational autoionization'' as well as ''electronic autoionization'', but the competing process of predissociation must also be taken into account. In this molecular domain, we have many experiments and many phenomena. The extant theories only deal with some cases, and are not yet able to explain some prominent observations. A group consisting of theorists and experimentalists active in the field of autoionization assembled at Argonne National Laboratory for a two-day Workshop on May 2-3, 1985, to try to provide some consensus of our present understanding and to point out the most promising direction for progress in the near future. Abstracts of individual items from the workshop were prepared separately for the data base.
Date: November 1, 1985
Creator: Berkowitz, J.; Berry, H. G. & Berry, R. S.
System: The UNT Digital Library
Photoelectron studies of autoionizing Rydberg states in HCl (open access)

Photoelectron studies of autoionizing Rydberg states in HCl

The results of a systematic investigation of electronically autoionizing Rydberg states in HCl are discussed. Vibrationally resolved photoelectron spectroscopy was used to map out the non-radiative decay of vibronic levels of 3psigma ..-->.. n(/sub d//sup s/)sigma Rydberg states converging to the A/sup 2/..sigma../sup +/(3psigma)/sup -1/ excited ionic state. The observed vibrational distributions of the resulting X/sup 2/PI(1..pi..)/sup -1/ ionic state are compared with the results of model calculations of Terwilliger and Smith based on spectral analysis of the absorption spectrum. Overall, the X/sup 2/PI vibrational branching ratios are found to be in only rough qualitative agreement with the calculations and these results are discussed in relation to the approximations involved. 18 refs., 4 figs., 1 tab.
Date: January 1, 1985
Creator: White, M. G. & Grover, J. R.
System: The UNT Digital Library
Clearance of Tc-99m DTPA Aerosol from Coal Miners' Lungs (open access)

Clearance of Tc-99m DTPA Aerosol from Coal Miners' Lungs

Alterations in regional epithelial permeability were assessed in 22 retired West Virginia coal miners' lungs by measuring the clearance of inhaled 0.5-..mu..m Tc-99m DTPA aerosol. Activity was measured in both lungs and in regions of interest placed over the lung periphery in the apical, middle, and basal portions of each lung. Clearance rates (T/sub 1/2/) for 5 nonsmokers, 8 ex-smokers, and 9 smokers were significantly faster than for comparable subjects measured elsewhere, who were not coal miners. Regional apex-to-base distributions of DTPA were measured as a function of clearance time and compared with regional ventilation and perfusion. Regional, as well as overall lung clearance curves of 8 smokers and 4 ex-smokers had two components, with overall T/sub 1/2/ of <7 min for the faster one. No correlations were found between T/sub 1/2/ and DLCO or with P(A-a)O/sub 2/. The results of our study suggest that measurement of DTPA clearance is a potentially useful noninvasive technique to assess lung injury in miners exposed to coal dust. 14 refs., 6 figs., 2 tabs.
Date: July 1, 1985
Creator: Susskind, H.; Brill, A. B. & Harold, W. H.
System: The UNT Digital Library
Borehole-calibration methods used in cased and uncased test holes to determine moisture profiles in the unsaturated zone, Yucca Mountain, Nevada (open access)

Borehole-calibration methods used in cased and uncased test holes to determine moisture profiles in the unsaturated zone, Yucca Mountain, Nevada

The use of drilling and coring methods that minimize the disturbance of formation rock and core has permitted field calibration of neutron-moisture tools in relatively large diameter cased and uncased boreholes at Yucca Mountain, Nevada. For 5.5-inch diameter cased holes, there was reasonable agreement between a field calibration in alluvium-colluvium and a laboratory calibration in a chamber containing silica sand. There was little difference between moisture-content profiles obtained in a neutron-access hole with a hand-held neutron-moisture meter and an automated borehole-logging tool using laboratory-generated calibration curves. Field calibrations utilizing linear regression analyses and as many as 119 data pairs show a good correlation between neutron-moisture counts and volumetric water content for sections of uncased 6-inch diameter boreholes in nonwelded and bedded tuff. Regression coefficients ranged from 0.80 to 0.94. There were only small differences between calibration curves in 4.25- and 6-inch uncased sections of boreholes. Results of analyzing field calibration data to determine the effects of formation density on calibration curves were inconclusive. Further experimental and theoretical work is outlined.
Date: December 31, 1985
Creator: Hammermeister, D.P.; Kneiblher, C.R. & Klenke, J.
System: The UNT Digital Library
Workshop on recent research in the Valles caldera (open access)

Workshop on recent research in the Valles caldera

Over the last 5 years, there has been increased interest in the geology of the Jemez Mountains volcanic field, New Mexico. Of special interest is the Toledo-Valles caldera complex, which is targeted for research coring as part of the Continental Scientific Drilling Program. The general topics covered in this workshop were (1) hydrothermal systems and rock-water interactions, (2) volcanology and structural framework of the Jemez volcanic field, (3) determining the presence or absence of melt below the Valles caldera, and (4) deep coring and drilling technology. Separate abstracts were prepared for each presentation.
Date: February 1, 1985
Creator: Heiken, G. (comp.)
System: The UNT Digital Library
Qualitative comparisons of fusion reactor materials for waste handling and disposal (open access)

Qualitative comparisons of fusion reactor materials for waste handling and disposal

The activation of five structural materials and seven coolant/breeder/multiplier materials in a common reference neutron environment was calculated with the FORIG activation code. The reference environment was the neutron flux and spectrum at the first wall of the mirror advanced reactor study (MARS) reactor. Qualitative comparison of these activated materials were made with respect to worker protection requirements for gamma radiation in handling the materials and with respect to their classifications for near-surface disposal of radioactive waste.
Date: April 8, 1985
Creator: Maninger, R.C.
System: The UNT Digital Library
Charge exchange processes involving iron ions (open access)

Charge exchange processes involving iron ions

A review and evaluation is given of the experimental data which are available for charge exchange processes involving iron ions and neutral H, H/sub 2/ and He. Appropriate scaling laws are presented, and their accuracy estimated for these systems. A bibliography is given of available data sources, as well as of useful data compilations and review articles. A procedure is recommended for providing single approximate formulae to the fusion community to describe total cross sections for electron capture by partially-stripped Fe/sup q+/ ions in collisions with H, H/sub 2/ and He, based on the scaling relationships suggested by Janev and Hvelplund.
Date: January 1, 1985
Creator: Phaneuf, R.A.
System: The UNT Digital Library
Neutron resonance averaging with filtered beams (open access)

Neutron resonance averaging with filtered beams

Neutron resonance averaging using filtered beams from a reactor source has proven to be an effective nuclear structure tool within certain limitations. These limitations are imposed by the nature of the averaging process, which produces fluctuations in radiative intensities. The fluctuations have been studied quantitatively. Resonance averaging also gives us information about initial or capture state parameters, in particular the photon strength function. Suitable modifications of the filtered beams are suggested for the enhancement of non-resonant processes.
Date: January 1, 1985
Creator: Chrien, R. E.
System: The UNT Digital Library
ATF neutral beam injection system (open access)

ATF neutral beam injection system

The Advanced Toroidal Facility is a stellarator torsatron being built at Oak Ridge National Laboratory to investigate improved plasma confinement schemes. Plasmas heating will be carried out predominantly by means of neutral beam injection. This paper describes the basic parameters of the injection system. Numerical calculations were done to optimize the aiming of the injectors. The results of these calculations and their implications on the neutral power to the machine are elaborated. The effects of improving the beam optics and altering the focal length on the power transmitted to the plasma are discussed.
Date: January 1, 1985
Creator: Menon, M.M.; Morris, R.N. & Edmonds, P.H.
System: The UNT Digital Library
Clean vacuum systems for RFTF (open access)

Clean vacuum systems for RFTF

The three vacuum systems to be used on the test facility are briefly described and their performance noted. (MOW)
Date: January 1, 1985
Creator: Livesey, R.L.
System: The UNT Digital Library
Applications of decelerated ions (open access)

Applications of decelerated ions

Many facilities whose sole purpose had been to accelerate ion beams are now becoming decelerators as well. The development and current status of accel-decel operations is reviewed here. Applications of decelerated ions in atomic physics experiments are discussed.
Date: March 1, 1985
Creator: Johnson, B. M.
System: The UNT Digital Library