20 Matching Results

Search Results

Advanced search parameters have been applied.

Free-ion spectra of interest to solid and solution spectroscopists

Description: A great deal of information is known about the free-ion spectra of the neutral and singly ionized rare earths because of the ease with which these spectra can be produced. Considerably less is known about the doubly and triply ionized rare earths. A discussion of the experimental difficulties, the present state of knowledge, and the predicted information are presented in this report. 6 references, 13 figures.
Date: January 1, 1985
Creator: Conway, J.G.
Partner: UNT Libraries Government Documents Department

Infrared spectrum of curium-244

Description: The spectrum of curium-244 has been observed on the high resolution Fourier-transform spectrometer at Laboratoire Aime Cotton. An electrodeless lamp containing 50 $mu$g of CmI$sub 3$ was run for 12 hours and 800,000 points were taken. A total of 1743 lines have been ascribed to curium and 87 percent of the lines have been assigned to transitions between known energy levels.
Date: September 1, 1974
Creator: Conway, J.G.; Blaise, J. & Verges, J.
Partner: UNT Libraries Government Documents Department

High temperature materials engineering properties evaluation (Task 57017). Summary report

Description: Declassified 21 Sep 1973. The following were studied: mechanical properties of WUO/sub 2/ -- ThO/sub 2/, Mo --54UO/sub 2/ --6ThO/sub 2/. W--3Re -- 54UO/sub 2/ -6ThO/sub 2/, Mo--50Re, W--30Re--3OMo, Ta and Ta --8W--2Hf; thermal expansion of W-25Re--30Mo and unclad and Ta-clad W--54UO/sub 2/--6ThO/sub 2/; and electric conductivity of Ta tubing and Ta-clad W--54UO/sub 2/-6ThO/sub 2/. (DLC)
Date: August 18, 1967
Creator: Conway, J.B. & McCullough, W.L.
Partner: UNT Libraries Government Documents Department

EVALUATIONS OF PLASTIC FATIGUE PROPERTIES OF HEAT-RESISTANT ALLOYS.

Description: Parameters affecting low-cycle fatigue life of AlSl 304, 316, and 348 were investigated. Test parameters were temperature, strain amplitude, strain rate, and length of hold times at peak strain in each cycle. Metallographic and fractographic analysis of 348 and 304 stainless tested at 650 and 816 deg C and strain rates of 4 x 10{sup -3}, 4 x 10{sup -4} and 4 x 10{sup -5} sec{sup -1} showed that the mode of crack initiation was intergranular for all conditions except for the highest strain rate at 650 deg C. At these conditions, the 304 exhibited a transgranular type crack initiated at the highest and lowest strain range evaluated. The 348 exhibited better strain fatigue resistance for a given total axial or plastic strain level. Fatigue resistance at 316 to 650 deg C is less than 304 or 348. The 316 exhibited strain hardening followed by softening over the entire range (F.S.)
Date: October 31, 1969
Creator: Conway, J.B.
Partner: UNT Libraries Government Documents Department

Spectroscopic studies of the transplutonium elements

Description: The challenging opportunity to develop insights into both atomic structure and the effects of bonding in compounds makes the study of actinide spectroscopy a particularly fruitful and exciting area of scientific endeavor. It is also the interpretation of f-element spectra that has stimulated the development of the most sophisticated theoretical modeling attempted for any elements in the periodic table. The unique nature of the spectra and the wealth of fine detail revealed make possible sensitive tests of both physical models and the results of Hartree-Fock type ab initio calculations. This paper focuses on the unique character of heavy actinide spectroscopy. It discusses how it differs from that of the lighter member of the series and what are the special properties that are manifested. Following the introduction, the paper covers the following: (1) the role of systematic studies and the relationships of heavy-actinide spectroscopy to ongoing spectroscopic investigations of the lighter members of the series; (2) atomic (free-ion) spectra which covers the present status of spectroscopic studies with transplutonium elements, and future needs and directions in atomic spectroscopy; (3) the spectra of actinide compounds which covers the present status and future directions of spectroscopic studies with compounds of the transplutonium elements; and other spectroscopies. 1 figure, 2 tables.
Date: January 1, 1983
Creator: Carnall, W.T. & Conway, J.G.
Partner: UNT Libraries Government Documents Department

Recent CDF results

Description: Preliminary results form the CDF detector, based on analysis of data collected in Run 1a and Run 1b at the Tevatron, totaling 110 pb{sup - 1} integrated luminosity, place new limits on the masses and couplings of new particles including charged Higgs bosons, supersymmetric gauge particles and quarks, and new vector bosons. One of the observed events, having an {ital e}{sup +}{ital e}{sup -} pair, two photons, and large missing energy would not occur with significant rate in the Standard Model, leading to speculation regarding its origin and the possible existence of related events.
Date: July 1, 1996
Creator: Conway, J. S.
Partner: UNT Libraries Government Documents Department

Setting limits and making discoveries in CDF

Description: This paper presents the statistical methods used in setting limits and discovery significances in the search for new particles in the CDF experiment at the Fermilab Tevatron. For single-channel counting experiments the collaboration employs the classical Helene formula, with Bayesian integration over systematic uncertainties in the signal acceptance and background. For more complex cases such as spectral fits and combining channels, likelihood-based methods are used. In the discoveries of the top quark and B{sub c} meson, the significance was estimated from the probability of the null hypothesis, using toy Monte Carlo methods. Lastly, in the recent SUSY/Higgs Workshop the Higgs Working Group used a method of combining channels and experiments based on the calculation of the joint likelihood for a particular experimental outcome, and averaging over all possible outcomes.
Date: May 15, 2000
Creator: Conway, J.
Partner: UNT Libraries Government Documents Department

PHYSICAL AND MECHANICAL PROPERTIES OF REACTOR MATERIALS.

Description: High temperature (to 3000 deg C) physical and mechanical properties for commercially available and newly developed materials being considered for use in high temperature reactors were measured. Creep, stress rupture, ductility, microstructure, and failure mechanism for tungsten were determined. Values were found for creep of as cast Mo; creep rupture of Re, Mo - Re - W, Mo - W, and Re - W; thermal conductivity and electrical resistivity of Re - W; and enthalpies, heat content and heat capacity of W. (F.S.)
Date: October 31, 1969
Creator: Conway, J.B. & Flagella, P.N.
Partner: UNT Libraries Government Documents Department

Electronic structure of neutral and singly ionized curium

Description: Extensive observations and analyses of the emission spectra of neutral and singly ionized curium, Cm I and Cm II, have resulted in the determination of 785 Cm I and 598 Cm II energy levels. These levels then combine to classify 9145 of the more than 14,250 lines of /sup 244/Cm observed between 240 and 2650 nm. Most of the levels have Lande g-values from Zeeman effect data and isotope shifts trom measurements of spectra from sources with various enrichments of /sup 244/Cm, /sup 245/Cm, /sup 246/Cm, and /sup 248/Cm. These data allowed many levels to be assigned to specific electronic configurations. The ground configurations of Cm I and Cm II are (Rn) 5f/sup 7/6d7s/sup 2/ and (Rn) 5f/sup 7/7s/sup 2/, respectively. The realtive energies of other electronic configurations of Cm are given and compared with analogous configurations in other actinides and in Gd its lanthanide analogue. 2 refs., 5 figs., 7 tabs.
Date: February 1, 1985
Creator: Worden, E.F.; Conway, J.G. & Blaise, J.
Partner: UNT Libraries Government Documents Department

THE 3d2 - 3d4f TRANSITIONS IN V IV

Description: The 3d4f levels in the spectrum of triply ionized vanadium, V IV, were located by L. Iglesias. She located these levels by identifying transitions from the 3d{sup 2} ground configuration to the 3d4p levels, then to the 3d4d levels and finally to the 3d4f levels. She also identified the transitions from the 3d4d levels to the 3d5p levels, continued up to the 3d5d levels, then back down to the 3d4f levels. Though the 3d4f levels were well established by two routes, the direct transitions from the ground state were not observed, being beyond her experimental range which stopped at 675 {angstrom}. We have photographed the spectrum of vanadium in the region of 190-650 {angstrom} and the direct transitions from 3d{sup 2} to 3d4f have been observed. The spectrum was excited with a vacuum sliding-spark discharge between vanadium metal electrodes separated by a quartz spacer as described previously. Peak discharge current was 1000 {angstrom}. The spectrum was photographed on Kodak SWR plates using the 10 {center_dot} 7 m grazing incidence spectrograph at the National Bureau of Standards in Washington, D.C. The plate factor in the region of interest is about 0.27 {angstrom}/mm. The plates were measured on a Grant comparator. Lines of yttrium IV and V, oxygen III and carbon IV were used for reference standards. The same plates were used to obtain the spectrum of vanadium V as reported previously by van Deurzen. Table I contains 19 transitions from the ground configuration, 3d{sup 2}, to the 3d4f configuration and 3 transitions from the ground configuration to the 3dSp configuration. Column 1 in the table is our measured vacuum wavelengths. The intensities in column 2 are visual estimates on a scale of 0 to 9. Column 3 lists the wavenumber of the measured lines. The classifications of the transitions and the ...
Date: September 1, 1977
Creator: Shalimoff, G. V. & Conway, J.G.
Partner: UNT Libraries Government Documents Department

SPECTRUM AND ENERGY LEVELS OF Pr{sup 3+} IN ThBr{sub 4}

Description: The strong features in the absorption spectrum and the laser excited fluorescence spectrum have been interpreted as arising from levels of Pr{sup 3+} in the D{sub 2d} symmetry site of ThBr{sub 4} . 43 energy levels have been fitted to the parameters with an RMS deviation of 61 cm{sup -1}. The values of the crystal field parameters are. B{sub 0}{sup 2} = 260.0 cm {sup -1}, B{sub 0}{sup 4} = - 644.2 cm{sup -1}, B{sub 4}{sup 4} = 929.2 cm{sup -1}, B{sub 0}{sup 6} = 1089.0 cm{sup -1} and B{sub 4}{sup 6} = 240.6 cm{sup -1}. The presence of other crystal symmetry sites is observed.
Date: June 1, 1980
Creator: Conway, J. G.; Krupa, J. C.; Delamoye, P. & Genet, M.
Partner: UNT Libraries Government Documents Department

The precision of higgs boson measurements and their implications

Description: The prospects for a precise exploration of the properties of a single or many observed Higgs bosons at future accelerators are summarized, with particular emphasis on the abilities of a Linear Collider (LC). Some implications of these measurements for discerning new physics beyond the Standard Model (SM) are also discussed.
Date: December 5, 2002
Creator: Conway, J.; Desch, K.; Gunion, J. F.; Mrenna, S. & Zeppenfeld, D.
Partner: UNT Libraries Government Documents Department

Status of gadolinium enrichment technology at LLNL

Description: A method based on,polarization selectivity and three step laser photoionization is presented for separation of the odd isotopes of gadolinium. Measurements of the spectroscopic parameters needed to quantify the excitation pathway are discussed. Model results are presented for the efficiency of photoionization. The vapor properties of electron beam vaporized gadolinium are presented which show dramatic cooling during the expansion of the hot dense vapor into a vacuum. This results in a significant increase in the efficiency of conversion of natural feed into enriched product in the AVLIS process. Production of enriched gadolinium for use in commercial power reactors appears to be economically viable using technology in use at LLNL.
Date: January 1, 1993
Creator: Haynam, C.; Comaskey, B.; Conway, J.; Eggert, J.; Glaser, J.; Ng, E. et al.
Partner: UNT Libraries Government Documents Department

Report of the Tevatron Higgs working group.

Description: Despite the success of the Standard Model (SM), which provides a superb description of a wide range of experimental particle physics data, the dynamics responsible for electroweak symmetry breaking is still unknown. Its elucidation remains one of the primary goals of future high energy physics experimentation. Present day global fits to precision electroweak data based on the Standard Model favor the existence of a weakly-interacting scalar Higgs boson, which is a remnant of elementary scalar dynamics that drives electroweak symmetry breaking. The only known viable theoretical framework incorporating light elementary scalar fields employs low-energy supersymmetry, where the scale of supersymmetry breaking is {Omicron} (1 TeV). The Higgs sector of the Minimal Supersymmetric extension of the Standard Model (MSSM) is of particular interest because it predicts the existence of a light CP-even neutral Higgs boson with a mass below about 130 GeV. Moreover, over a significant portion of the MSSM parameter space, the properties of this scalar are indistinguishable from those of the SM Higgs boson.
Date: November 14, 2000
Creator: Carena, M.; Conway, J. S.; Haber, H. E.; Hobbs, J. D.; Harris, B. W.; Kuhlmann, S. et al.
Partner: UNT Libraries Government Documents Department

Exotic physics: search for new physics leading to high mass tau pairs with ppbar collisions at 1.96 tev using cdf ii

Description: Abstract: We present the results of a search for anomalous resonant production of tau lepton pairs with large invariant mass, the first such search using the CDF II Detector in Run II of the Tevatron p{bar p} collider. Such anomalous production could arise from various new physics processes. In a data sample corresponding to 195 pb{sup -1} of integrated luminosity we predict 2.8 {+-} 0.5 events from Standard Model background processes and observe 4. We use this result to set limits on the production of heavy scalar and vector particles decaying to tau lepton pairs.
Date: June 15, 2005
Creator: Academia Sinica Institute of Physics
Partner: UNT Libraries Government Documents Department