Capture cross sections in the KeV region

Many workers have attempted to determine neutron absorption cross sections and average resonance parameters with varying degrees of success. Values of the latter parameters for a given isotope often vary as much as a factor of two or three from one worker to another. This dissertation is an attempt to remove some of this uncertainty. Natural silver and the isotopes ¹⁰⁷Ag, ¹⁰⁹Ag, ¹¹⁵In, ¹²⁷I have been irradiated by the monoenergetic neutrons emitted at 90° to a proton beam striking a ⁷Li target. These samples were then counted for their β and γ activity and their absolute cross sections relative to the cross section of ¹²⁷I at 24 keV were calculated over the energy range of from 3 to 155 keV. These measured cross section versus energy curves were used to determine the γ-ray strength functions, (r_γ)/( D_o), the s-wave neutron strength functions, (r¹_n)/(D), and the p-wave neutron strength functions (r¹_n)/(D). Because of data limitations it has been assumed that the γ-ray strength function is the same for both s- and p-wave neutrons. The cross sections determined are in general good agreement with the values previously reported but differ somewhat in shape. This shape variance results in values for the average resonance parameters which are somewhat higher than values reported by other workers.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Physics

Department dc:contributor.department

Physics

Grantor dc:publisher

Virginia Polytechnic Institute

Year dc:date.issued

1969

Author dc:creator

• Campbell, Wayne Wesley

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/74749

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/74749