Measurement of the Capture Cross Section of Thorium
Author : James W. Wade
Publisher :
Page : 16 pages
File Size : 12,20 MB
Release : 1957
Category : Neutron cross sections
ISBN :
Author : James W. Wade
Publisher :
Page : 16 pages
File Size : 12,20 MB
Release : 1957
Category : Neutron cross sections
ISBN :
Author :
Publisher :
Page : pages
File Size : 41,11 MB
Release : 1976
Category :
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The shape of the thorium absorption cross section near thermal energies was investigated. This shape is dominated by one or more negative energy resonances whose parameters are not directly known, but must be inferred from higher energy data. Since the integral quantity most conveniently describing the thermal cross section shape is the Westcottg-factor, effort was directed toward establishing this quantity to high precision. Three nearly independent g-factor estimates were obtained from measurements on a variety of foils in three different neutron spectra provided by polyethylene-moderated neutrons from a 252Cf source and from irradiations in the National Bureau of Standards ''Standard Thermal Neutron Density.'' The weighted average of the three measurements was 0.993 +- 0.004. This is in good agreement with two recent evaluations and supports the adequacy of the current cross section descriptions.
Author : G. M. Benson
Publisher :
Page : 36 pages
File Size : 40,31 MB
Release : 1962
Category : Measured values
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Author :
Publisher :
Page : pages
File Size : 17,21 MB
Release : 1981
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A 232Th total cross section measurement in the resolved resonance region has been requested with a 2% accuracy in order to obtain resonance parameters with a 5% accuracy. These data are required for both fast and light-water breeder reactor studies. Inspection of the prior 232Th differential data base shows several problems: the thermal cross sections seem inconsistent; the measured capture widths have large uncertanties; the two rather complete sets of measured neutron widths are systematically discrepant; and the differential data appear to give Cd capture ratios and shielded-capture resonance integrals smaller than those required by integral measurements. In order to improve the differential data base we have measured neutron transmission spectra through eight samples of 232Th. Resonance parameters have been obtained from these data using the computer code S10B. Fits to these data up to 440 eV, which concentrated on the capture widths, have been previously reported. The results of extending these fits to 2.0 keV are reported and discussed in terms of the s-wave strength function and the dilute-capture resonance integral. (WHK).
Author :
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Page : pages
File Size : 39,28 MB
Release : 1979
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The recent evaluation of the cross-section data bases for /sup 232/Th capture and fission emphasized significant normalization discrepancies between the available differential data. To help resolve the normalization discrepancies, the capture and fission integral cross sections were measured for /sup 232/Th in the fast neutron zone of the Coupled Fast Reactivity Measurements Facility (CFRMF). The cross sections are derived from the radiometric determination of the saturation reaction rates for fission and capture based on the Ge(Li) spectrometric measurement of the absolute gamma emission rates of the 537-keV and 1596-keV lines in the /sup 140/Ba - /sup 140/La decay and the 311.9-keV line in the /sup 233/Pa decay. For capture and fission, respectively, the measured integral cross sections are 291 mb +- 3% and 19.6 mb +- 5%. The ratios of the integral cross sections computed with ENDF/B-IV thorium cross sections and the CFRMF neutron spectrum to the above values are 0.99 for capture and 0.90 for fission. 19 references.
Author : U.S. Atomic Energy Commission
Publisher :
Page : 68 pages
File Size : 27,51 MB
Release : 1959
Category : Cross sections (Nuclear physics)
ISBN :
Author : Mark James Vermeulen
Publisher :
Page : pages
File Size : 46,82 MB
Release : 2015
Category :
ISBN :
Author :
Publisher :
Page : pages
File Size : 36,13 MB
Release : 1978
Category :
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The 232Th(n, .gamma.) cross section was measured between 30 keV and 2.5 MeV. A large liquid scintillator was used to measure the shape of the cross section relative to Au(n, .gamma.) between 58 keV and 850 keV. The activation technique was used in measurements at 30 keV relative to Au(n, .gamma.) and above 240 keV relative to 235U(n, f). The activation results were utilized to normalize the shape data. The results agree well with recent experimental data by Lindner et al. and are substantially lower than the evaluated data file ENDF/B-IV in the several-hundred-keV range.
Author : C L Dunford
Publisher : World Scientific
Page : 756 pages
File Size : 36,51 MB
Release : 1993-08-12
Category :
ISBN : 981455345X
The Symposium on Nuclear Data Evaluation Methodology provided a forum for the discussion of developments made over the past 12 years in the evaluation methods used for generating data files for applied technology. With a program that was prepared by an international committee of experts in this field, this set of proceedings gives a comprehensive overview of the development and progress of this field for the last 12 years. It serves as an important source of reference and historical update for those seeking an in-depth understanding of this study.
Author : Stanley H. Levinson
Publisher :
Page : pages
File Size : 46,60 MB
Release : 1979
Category :
ISBN :