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Some comments on resolution and the analysis and interpretation of experimental results from differential neutron measurements

Description: Effects of finite resolution in differential neutron measurements are examined. General procedures for deriving the experimental resolution functions from a knowledge of the experimental parameters are presented. Problems encountered in the comparison of different data sets, when the measured cross section is known to fluctuate with energy, are discussed. The objective is to encourage closer attention to the matter of resolution by experimenters, evaluators and users of neutron nuclear data.
Date: November 1, 1979
Creator: Smith, D.L.
Partner: UNT Libraries Government Documents Department

Cross section measurement for the /sup 52/Cr(n,p)/sup 52/V reaction near threshold

Description: Cross sections for this reaction were determined in the range 5.3 to 9 MeV using a previously-reported pulsed-accelerator technique to measure gamma ray activity from 3.75 m /sup 52/V. Very few experimental data have been reported for this reaction, and little was known about the threshold region prior to the present experiment. The results of this work (in conjunction with other available cross section information) were used in the computation of fission-spectrum averages which are of interest for reactor applications.
Date: January 1, 1979
Creator: Smith, D.L. & Meadows, J.W.
Partner: UNT Libraries Government Documents Department

Measured and evaluated bismuth data for fusion-fission-hybrid and electro-nuclear breeding applications. [1 to 5 MeV]

Description: Neutron total and scattering cross sections of elemental bismuth are measured to energies of approximately 4.5 MeV. The experimental results are used to deduce an optical-statistical model that is quantitatively descriptive of the measured values and of higher-energy results reported in the literature. The measured and calculated values, together with the body of information available in the literature, are utilized to derive a comprehensive evaluated nuclear data file in the ENDF format. This evaluation extends from 10/sup -5/ eV to 20 MeV, addresses neutron-induced and photon-emission processes, and is oriented toward the needs of fusion-fission-hybrid and electro-nuclear breeding applications. 4 figures, 1 table.
Date: January 1, 1979
Creator: Guenther, P.T.; Smith, A.B.; Smith, D.L.; Whalen, J.F. & Howerton, R.
Partner: UNT Libraries Government Documents Department

Measurement of the fast neutron capture cross section of /sup 238/U relative to /sup 235/U(n,f)

Description: The capture cross section of /sup 238/U was measured using the activation technique and /sup 235/U(n,f) as a reference cross section. Capture events were measured by detection of two prominent ..gamma..-transitions in the decay of the /sup 239/U daughter nuclide, /sup 239/Np, employing a high resolution Ge(Li) detector. The system was calibrated with samples activated in a thermal neutron flux relative to the capture cross section of gold, and with an absolutely calibrated ..cap alpha..-emitter, /sup 243/Am, which decays to /sup 239/Np. Cross section measurements were carried out in the neutron energy range from 30 keV to 3 MeV. Emphasis was on absolute values between 150 keV and 1 MeV where the /sup 238/U(n,..gamma..) cross section and its cross section is small. Background from fission products was found to restrict the accuracy of the measured data at energies > 1.5 MeV.
Date: January 1, 1979
Creator: Fawcett, L.R. Jr.; Poenitz, W.P. & Smith, D.L.
Partner: UNT Libraries Government Documents Department

Discrepancy between differential and integral results for the /sup 63/Cu(n,. cap alpha. )/sup 60/Co cross sections. [Threshold to 10 MeV]

Description: The threshold-reaction /sup 63/Cu(n,..cap alpha..)/sup 60/Co is of special importance in reactor dosimetry for long-term fast-flux integration. The inconsistency in the available differential and integral data base has limited the applicability of that reaction as a reliable monitor. The availability of results from a recent measurement of the excitation function for the reaction /sup 63/Cu(n,..cap alpha..) at ANL prompted a further investigation of this problem. The implications of the new data are discussed. 24 references.
Date: January 1, 1979
Creator: Winkler, G.; Smith, D.L. & Meadows, J.W.
Partner: UNT Libraries Government Documents Department

First wall and blanket design for the STARFIRE commercial tokamak power reactor

Description: The first wall and blanket design concepts being evaluated for the STARFIRE commercial tokamak reactor study are presented. The two concepts represent different approaches to the mechanical design of a tritium breeding blanket using the reference materials options. Each concept has a separate ferritic steel first wall cooled by heavy water (D/sub 2/O), and a ferritic steel blanket with solid lithium oxide breeder cooled by helium. A separate helium purge system is used in both concepts to extract tritium. The two concepts are compared and relative advantages and disadvantages for each are discussed.
Date: January 1, 1979
Creator: Morgan, G.D.; Trachsel, C.A.; Cramer, B.A.; Bowers, D.A. & Smith, D.L.
Partner: UNT Libraries Government Documents Department

Assessment of solid breeding blanket options for commercial tokamak reactors

Description: This study examines the materials and design implications regarding the use of solid breeding materials with respect to compatibility with structure and coolant, tritium processing, chemical and radiation stability and thermal-hydraulics. Four solid breeding materials considered, viz., Li/sub 7/Pb/sub 2/, Li/sub 2/O, Li/sub 2/SiO/sub 3/ and LiAlO/sub 2/, are representative of the metallic and ceramic compounds available. The major design problems regarding the use of solid breeding materials relate to the limited range of operating temperatures acceptable for tritium release and chemical stability or compatibility. The allowable ranges of breeder temperatures for which in-situ tritium recovery is potentially viable are evaluated for the candidate breeding materials.
Date: January 1, 1979
Creator: Smith, D.L.; Clemmer, R.G. & Davis, J.W.
Partner: UNT Libraries Government Documents Department