skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: SOURCES 4A: A Code for Calculating (alpha,n), Spontaneous Fission, and Delayed Neutron Sources and Spectra

Abstract

SOURCES 4A is a computer code that determines neutron production rates and spectra from ({alpha},n) reactions, spontaneous fission, and delayed neutron emission due to the decay of radionuclides. The code is capable of calculating ({alpha},n) source rates and spectra in four types of problems: homogeneous media (i.e., a mixture of {alpha}-emitting source material and low-Z target material), two-region interface problems (i.e., a slab of {alpha}-emitting source material in contact with a slab of low-Z target material), three-region interface problems (i.e., a thin slab of low-Z target material sandwiched between {alpha}-emitting source material and low-Z target material), and ({alpha},n) reactions induced by a monoenergetic beam of {alpha}-particles incident on a slab of target material. Spontaneous fission spectra are calculated with evaluated half-life, spontaneous fission branching, and Watt spectrum parameters for 43 actinides. The ({alpha},n) spectra are calculated using an assumed isotropic angular distribution in the center-of-mass system with a library of 89 nuclide decay {alpha}-particle spectra, 24 sets of measured and/or evaluated ({alpha},n) cross sections and product nuclide level branching fractions, and functional {alpha}-particle stopping cross sections for Z < 106. The delayed neutron spectra are taken from an evaluated library of 105 precursors. The code outputs the magnitude and spectramore » of the resultant neutron source. It also provides an analysis of the contributions to that source by each nuclide in the problem.« less

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Los Alamos National Lab., NM (US)
Sponsoring Org.:
USDOE Office of Nonproliferation and National Security (NN) (US)
OSTI Identifier:
15215
Report Number(s):
LA-13639-MS
TRN: US0101617
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 1 Sep 1999
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; S CODES; ANGULAR DISTRIBUTION; CENTER-OF-MASS SYSTEM; CROSS SECTIONS; DELAYED NEUTRONS; NEUTRON SOURCES; RADIOISOTOPES; SPECTRA; SPONTANEOUS FISSION; ALPHA REACTIONS

Citation Formats

Madland, D.G., Arthur, E.D., Estes, G.P., Stewart, J.E., Bozoian, M., Perry, R.T., Parish, T.A., Brown, T.H., England, T.R., Wilson, W.B., and Charlton, W.S. SOURCES 4A: A Code for Calculating (alpha,n), Spontaneous Fission, and Delayed Neutron Sources and Spectra. United States: N. p., 1999. Web. doi:10.2172/15215.
Madland, D.G., Arthur, E.D., Estes, G.P., Stewart, J.E., Bozoian, M., Perry, R.T., Parish, T.A., Brown, T.H., England, T.R., Wilson, W.B., & Charlton, W.S. SOURCES 4A: A Code for Calculating (alpha,n), Spontaneous Fission, and Delayed Neutron Sources and Spectra. United States. doi:10.2172/15215.
Madland, D.G., Arthur, E.D., Estes, G.P., Stewart, J.E., Bozoian, M., Perry, R.T., Parish, T.A., Brown, T.H., England, T.R., Wilson, W.B., and Charlton, W.S. Wed . "SOURCES 4A: A Code for Calculating (alpha,n), Spontaneous Fission, and Delayed Neutron Sources and Spectra". United States. doi:10.2172/15215. https://www.osti.gov/servlets/purl/15215.
@article{osti_15215,
title = {SOURCES 4A: A Code for Calculating (alpha,n), Spontaneous Fission, and Delayed Neutron Sources and Spectra},
author = {Madland, D.G. and Arthur, E.D. and Estes, G.P. and Stewart, J.E. and Bozoian, M. and Perry, R.T. and Parish, T.A. and Brown, T.H. and England, T.R. and Wilson, W.B. and Charlton, W.S.},
abstractNote = {SOURCES 4A is a computer code that determines neutron production rates and spectra from ({alpha},n) reactions, spontaneous fission, and delayed neutron emission due to the decay of radionuclides. The code is capable of calculating ({alpha},n) source rates and spectra in four types of problems: homogeneous media (i.e., a mixture of {alpha}-emitting source material and low-Z target material), two-region interface problems (i.e., a slab of {alpha}-emitting source material in contact with a slab of low-Z target material), three-region interface problems (i.e., a thin slab of low-Z target material sandwiched between {alpha}-emitting source material and low-Z target material), and ({alpha},n) reactions induced by a monoenergetic beam of {alpha}-particles incident on a slab of target material. Spontaneous fission spectra are calculated with evaluated half-life, spontaneous fission branching, and Watt spectrum parameters for 43 actinides. The ({alpha},n) spectra are calculated using an assumed isotropic angular distribution in the center-of-mass system with a library of 89 nuclide decay {alpha}-particle spectra, 24 sets of measured and/or evaluated ({alpha},n) cross sections and product nuclide level branching fractions, and functional {alpha}-particle stopping cross sections for Z < 106. The delayed neutron spectra are taken from an evaluated library of 105 precursors. The code outputs the magnitude and spectra of the resultant neutron source. It also provides an analysis of the contributions to that source by each nuclide in the problem.},
doi = {10.2172/15215},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {9}
}