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in creator/contributor: "Hill, N. W."

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Neutron total cross section of $sup 6$Li from 10 eV to 10 MeV

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Date: April 30, 1975

Creator: Harvey, J.A. & Hill, N.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron total cross section measurements for /sup 249/Bk and /sup 249/Cf

Total neutron cross sections have been measured for /sup 249/Bk and its ..beta.. decay daughter, /sup 249/Cf. Single level Breit-Wigner resonance analysis has been performed for 35 resonances below 62 eV in Bk and for 10 resonances below 10 eV in Cf. (SDF)

Date: January 1, 1977

Creator: Benjamin, R. W.; Harvey, J. A. & Hill, N. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron total cross section of /sup 233/U from 0. 01 to 1. 0 eV

The neutron total cross section of /sup 233/U from 0.01 to 1.0 eV was measured at ORELA using a repetition rate of 25 sec/sup -1/ and a 17.872-meter flight path. Two samples of /sup 233/U enriched to 99.76% with inverse thicknesses of 165.2 and 321.1 barns/atom were measured. The data were corrected for neutron and gamma ray backgrounds which were less than or equal to 1%. Results from the two samples are in good agreement. The data are compared to earlier data and to ENDF/B-V evaluation.

Date: January 1, 1979

Creator: Harvey, J.A.; Moore, C.L. & Hill, N.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of the neutron total cross section of sodium from 32 keV to 37 MeV

The neutron transmission through a 8.1-cm sample of pure sodium has been measured for neutron energies between 32.5 keV and 37.4 MeV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons, which were detected at the 200-m flight path by a NE-110 proton recoil detector. The experimental results are tabulated and compared with the total cross section in the ENDF/B-IV file for sodium.

Date: October 1, 1976

Creator: Larson, D. C.; Harvey, J. A. & Hill, N. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Neutron filters for producing monoenergetic neutron beams

Neutron transmission measurements have been made on high-purity, highly-enriched samples of /sup 58/Ni (99.9%), /sup 60/Ni (99.7%), /sup 64/Zn (97.9%) and /sup 184/W (94.5%) to measure their neutron windows and to assess their potential usefulness for producing monoenergetic beams of intermediate energies from a reactor. Transmission measurements on the Los Alamos Sc filter (44.26 cm Sc and 1.0 cm Ti) have been made to determine the characteristics of the transmitted neutron beam and to measure… more

Date: January 1, 1982

Creator: Harvey, J.A.; Hill, N.W. & Harvey, J.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron, alpha and total widths and spin assignments for resonances in /sup 33/S + N from 10-400 keV

The S-33 neutron total cross section has been measured from 10 keV to 1 MeV. Resonance parameters (E/sub n/, GAMMA/sub n/, GAMMA/sub ..cap alpha../, J/sup ..pi../) have been derived in the region from 10 keV to 400 keV.

Date: January 1, 1984

Creator: Coddens, G.P.; Salah, M.; Harvey, J.A. & Hill, N.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Solid-state effects on thermal-neutron cross sections and on low-energy resonances

The neutron total cross sections of several single crystals (Si, Cu, sapphire), several polycrystalline samples (Cu, Fe, Be, C, Bi, Ta), and a fine-powder copper sample have been measured from 0.002 to 5 eV. The Cu powder and polycrystalline Fe, Be and C data exhibit the expected abrupt changes in cross section. The cross section of the single crystal of Si is smooth with only small broad fluctuations. The data on two single Cu crystals, the sapphire crystal, cast Bi, and rolled samples of Ta a… more

Date: January 1, 1982

Creator: Harvey, J.A.; Mook, H.A.; Hill, N.W. & Shahal, O.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of the neutron total cross section of natural magnesium from 9 keV to 39 MeV. [Tables, resonance]

The neutron transmission through a 5.09-cm sample of natural magnesium was measured for neutron energies between 9 keV and 39 MeV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons, which were detected at the 200-m flight path by a NE-110 proton recoil detector. The experimental results are tabulated and compared with the total cross section in the ENDF/B-IV file for magnesium.

Date: June 1, 1978

Creator: Larson, D.C.; Harvey, J.A.; Hill, N.W. & Weigmann, H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Neutron, alpha and total widths and spin assignments for resonances in /sup 33/S + n from 10 to 400 keV

Date: January 1, 1984

Creator: Coddens, G.P.; Salah, M.; Harvey, J.A. & Hill, N.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of the 2. 35 MeV window in O + n

Calculations are made showing that the ion temperature of a deuterium plasma with a Maxwellian distribution can be found by measuring the transmission of the d-d neutrons through liquid oxygen. The method is useful for temperatures up to 6 keV. It does not depend on the absolute neutron yield but does require accurate total neutron cross sections for oxygen. In this experiment the cross section of natural oxygen was measured from 2.0 to 3.0 by neutron time-of-flight at the Oak Ridge Electron Li… more

Date: January 1, 1979

Creator: Johnson, C. H.; Fowler, J. L.; Hill, N. W. & Ortolf, J. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron total cross section of /sup 240/Pu below 6 eV and the parameters of the 1. 0-eV resonance

Measurements of the low-energy neutron transmission of five different /sup 240/Pu samples have been made using the Oak Ridge Electron Linear Accelerator (ORELA) pulsed-neutron source and the time-of-flight technique in an attempt to resolve discrepancies between the evaluated low-energy cross section of this nuclide and the observed production of heavier Pu isotopes in light-water reactors (LWRs). Three ''thin'' samples consisting of Pu metal foils containing 0.73 at. % /sup 240/Pu were measure… more

Date: January 1, 1985

Creator: Spencer, R. R.; Harvey, J. A.; Hill, N. W. & Weston, L. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron capture and total cross sections for /sup 48/Ca: astrophysical implications

Attempts to understand abundance anomalies of the Ca isotopes in the Allende meteorite via the n..beta..-process require 30-keV Maxwellian averaged capture cross sections. Experimental data on /sup 48/Ca in this energy region of astrophysical significance is important since a single resonance in this vicinity could dominate the capture cross section. Neutron capture and total cross section measurements have been performed at ORELA on a 9.97-g sample of CaCO/sub 3/, enriched to 96% /sup 48/Ca, o… more

Date: January 1, 1984

Creator: Carlton, R.F.; Harvey, J.A.; Hill, N.W. & Macklin, R.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of the neutron total cross section of silicon from 5 eV to 730 keV

Neutron transmission through natural silicon samples has been measured for neutron energies between 5 eV and 730 keV. The Oak Ridge Electron Linear Accelerator (ORELA) was used to provide the neutrons. The 80-m flight path with a /sup 6/Li glass detector was used for the low energy measurement, and the 200-m flight path with a NE-110 detector was used for the higher energy measurements. The 1,488 resulting values are tabulated and compared with the current ENDF/B-IV evaluation.

Date: November 1, 1976

Creator: Larson, D. C.; Johnson, C. H.; Harvey, J. A. & Hill, N. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Measurement of the neutron total cross section of fluorine from 5 eV to 20 MeV

Neutron transmissions through Teflon (CF/sub 2/) and carbon were measured to provide high resolution transmission and cross sections for fluorine from 5 eV to 20 MeV. The Oak Ridge Electron Linear Accelerator (ORELA) was used for the neutron source. The 80-m flight path with a /sup 6/Li glass detector was used for the low-energy measurements, and the 200-m flight path with a NE-110 detector was used for the higher energy measurements. The various background contributions were carefully studied … more

Date: October 1, 1976

Creator: Larson, D. C.; Johnson, C. H.; Harvey, J. A. & Hill, N. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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/sup 187/Os + n resonance parameters in the interval 27-500 eV neutron energies

The neutron total cross section for /sup 187/Os, in the energy range, 27 eV to 500 eV, has been measured at the ORELA facility by the neutron time-of-flight technique, utilizing a 2.0 gm osmium sample (n = 0.008401 Os-nuclei/barn) enriched to 70.38% /sup 187/Os. Measurements were performed at a 80 m flight station with an energy resolution, ..delta..E/E, of 0.1% using a /sup 6/Li glass scintillator. Resolved resonances have been analyzed by a Reich-Moore multilevel code (SAMMY) to obtain parame… more

Date: January 1, 1982

Creator: Winters, R. R.; Carlton, R. F.; Harvey, J. A. & Hill, N. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron total cross-section measurements of /sup 9/Be, /sup 10/ /sup 11/B, and /sup 12/ /sup 13/C from 1. 0 to 14 MeV using the /sup 9/Be(d,n)/sup 10/B reaction as a ''white'' neutron source

High-resolution and high-accuracy total cross sections of /sup 9/Be, /sup 10/ /sup 11/B, and /sup 12/ /sup 13/C have been measured from 1.0 to 14 MeV. The Los Alamos Scientific Laboratory (LASL) tandem accelerator was used to produce a ''white'' source of neutrons by stopping a pulsed beam of 15-MeV deuterons in a thick beryllium target. The neutron energy resolution (full width at half maximum (FWHM)) achieved in kiloelectron volts is given by 1.4 E (MeV)/sup /sup 3///sub 2//, and the accuracy… more

Date: June 1, 1977

Creator: Auchampaugh, G. F.; Ragan, C. E., III; Plattard, S. & Hill, N. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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High-resolution neutron transmission measurements on /sup 235/U, /sup 239/Pu, and /sup 238/U

High-resolution transmission measurements have been made on three sample thicknesses of both /sup 235/U and /sup 239/Pu at liquid nitrogen temperature and also on three of /sup 238/U at room temperature using neutrons from the water-moderated ORELA target. The data on /sup 235/U and /sup 239/Pu from 1 to 10,000 eV were obtained using /sup 6/Li glass scintillation detectors at 17.909-and 80.394-m flight paths. The /sup 238/U data from 1 to 100 keV were obtained using a new NE 110 proton-recoil s… more

Date: January 1, 1988

Creator: Harvey, J.A.; Hill, N.W.; Perey, F.G.; Tweed, G.L. & Leal, L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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/sup 58/Ni + n transmission, capture and differential elastic scattering data analysis in the resonance region

High-resolution neutron transmission, capture and differential elastic scattering measurements have been made for /sup 58/Ni-enriched targets at the Oak Ridge Electron Linear Accelerator (ORELA) from the eV to the MeV region. The three sets of data were analyzed simultaneously from 10 to 450 keV, and the transmission analysis was extended to 650 keV. For the 52 s-wave resonances observed between 10 and 650 keV, the average level spacing, D/sub 0/, and the strength function, S/sub 0/, are 12.2 +… more

Date: January 1, 1985

Creator: Perey, C.M.; Perey, F.G.; Harvey, J.A.; Hill, N.W. & Macklin, R.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Accurate determination of the parameters of the 292. 4-eV resonance of /sup 91/Zr and the 301. 1-eV resonance of /sup 96/Zr

High-resolution transmission measurements of zirconium metal samples have been carried out at ORELA using the 80-m flight path and an improved /sup 6/Li-glass scintillation neutron detector. Four different thicknesses of the pure zirconium metal and one sample of zircaloy were used in four separate experiments. The transmission data for these samples were measured at room temperature, and one sample was cooled to liquid nitrogen temperature. These data were analyzed using the multilevel R-matri… more

Date: January 1, 1985

Creator: Salah, M.M.; Harvey, J.A.; Hill, N.W.; Hussein, A.Z. & Perey, F.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron total cross section measurements on /sup 249/Cf. [0. 01 to 90 eV]

Neutron total cross section measurements were performed on a sample of /sup 249/Cf (5.65 mg total weight) with the ORELA as a source of pulsed neutrons. The sample, the inverse thickness of which was 1542 barns/atom, consisted of 85.3% /sup 249/Cf and 14.4% /sup 249/Bk, and was cooled to liquid nitrogen temperature. Analyses were also made of data from a thin sample (l/n = 17430) of 65% /sup 249/Cf in the region of the large fission resonance at 0.7 eV. Fifty-five resonances in /sup 249/Cf were… more

Date: January 1, 1979

Creator: Carlton, R. F.; Harvey, J. A.; Hill, N. W.; Pandey, M. S. & Benjamin, R. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A study of the /sup 235/U(n,f) cross section in the 3 to 30 MeV energy region

The /sup 235/U(n,f) cross section is often considered the most favorable of the neutron cross section standards. Above a few MeV, however, the uncertainties are still unacceptably high, except for the 14 MeV region. In an effort to improve the accuracy of this cross section, measurements have been initiated at the new target 4 facility at the Los Alamos National Laboratory (LANL) 800 MeV proton accelerator. This target provides an intense source of high energy neutrons at the 20 meter flight pa… more

Date: January 1, 1988

Creator: Carlson, A. D.; Wasson, O. A.; Lisowski, P. W.; Ullmann, J. L. & Hill, N. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Majority-logic NE-110 detector for keV neutrons

An NE-110 proton-recoil scintillation counter whose efficiency is reproducible and stable has been developed for neutrons in the energy range from 5 keV to 1 MeV. Majority-of-logic at below the single photoelectron level is used between two or more phototubes viewing the same scintillator. Pulse height distributions as a function of neutron energy have been measured between 5 and 350 keV with two different detector configurations: a thin square slab of NE-110 and a cylinder of NE-110. The absol… more

Date: January 1, 1984

Creator: Hill, N. W.; Harvey, J. A.; Horen, D. J.; Morgan, G. L. & Winters, R. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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K-components for the approx. 1. 4-, approx. 1. 6-, and approx. 1. 7-MeV structures in the fission of /sup 232/Th + n

Neutron-induced angle-integrated fission cross sections of /sup 232/Th were measured from 0.7 to 9 MeV with a nominal neutron energy resolution of 0.15 ns/m. Data were taken for the angular intervals 0 to 23.4/sup 0/, 0 to 33.7/sup 0/, 0 to 51.7/sup 0/, and 0 to 90/sup 0/. The structures at approx. 1.4, approx. 1.6, and approx. 1.7 MeV were interpreted in terms of rotational bands with K = 1/2, 3/2, and greater than or equal to 5/2. The approximate relative fission strengths for the K-bonds are… more

Date: July 1, 1981

Creator: Auchampaugh, G. F.; Plattard, S.; Hill, N. W.; de Saussure, G.; Perez, R. B. & Harvey, J. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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High-resolution fission cross section of /sup 231/Pa. [0. 1 to 12 MeV and 0. 4 eV to 10 keV]

A high resolution fission cross section for /sup 231/Pa was measured at ORELA from 0.1 to 12 MeV and between 0.4 eV and 10 keV. The data show evidence for (1) fractionated vibrational structures in the threshold region of the fission cross section, and (2) narrow fisson resonances above 1.3 eV with an average fission width < GAMMA/sub f/ > = 8 ..mu..eV. 16 references.

Date: January 1, 1979

Creator: Plattard, S.; Auchampaugh, G. F.; Hill, N. W.; de Saussure, G.; Perez, R. B. & Harvey, J. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department