Nucleon-induced excitation of collective bands in /sup 12/C and the application to neutron dosimetry at E/sub n/ > 20 MeV

Thesis/Dissertation · Sun Jan 01 00:00:00 EST 1984

OSTI ID:5427937

Soleimani Meigooni, A

This work involves the measurement and analysis of neutron elastic and inelastic scattering cross section from /sup 12/C at incident neutron energies between 20 and 26 MeV. These data cover an energy range that has not previously been investigated with neutrons and where the direct interaction mechanism should be dominant. These energies are also of particular interest in the fields of radiation protection and radio-therapy. The objectives of the present work are to analyze excitation of the measured collective states in /sup 12/C and to develop an energy dependent optical model potential that can be used to calculate quantities of importance to neutron dosimetry at all energies between 20 and 100 MeV. In addition, a separate series of experiments was performed using a large sample (47.45 gm) at 22 and 24 MeV to investigate the weakly excited states above the 3/sub 1/..sqrt..(9.641 MeV) level in /sup 12/C. Differential cross sections for nine excited states in the first 15 MeV excitation of /sup 12/C were resolved and measured. New rotation-vibration formalisms were developed to be used with the code ECIS79 in order to analyze the collective motions of /sup 12/C. Excellent agreement between experimental data and theoretical calculation is obtained for (a) the ground state rotation band, (b) O/sub 2//sup +/ (7.655 MeV) state using ..beta..-vibration plus breathing mode, (c) the 1/sub 1//sup -/ (10.84 MeV) and 2/sub 1//sup -/ (11.83 MeV) states using K/sup ..pi../ = 1/sup -/ octupole vibration, and (d) the 3/sub 1//sup -/ (9.64 MeV) and 4/sub 1//sup -/ (13.35 MeV) states using K/sup ..pi../ = 3/sup -/ octupole vibration. An energy dependent optical model potential has been obtained that describes the present neutron scattering data, differential proton scattering data of higher energies and total neutron cross sections between 20 and 100 MeV.

• Research Organization: Ohio Univ., Athens (USA)
• OSTI ID: 5427937
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CARBON 12 TARGET
NEUTRON REACTIONS
ELASTIC SCATTERING
INELASTIC SCATTERING
ANGULAR DISTRIBUTION
CROSS SECTIONS
ENERGY LEVELS
EXCITATION
EXPERIMENTAL DATA
MEV RANGE 10-100
OPTICAL MODELS
BARYON REACTIONS
DATA
DISTRIBUTION
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
HADRON REACTIONS
INFORMATION
MEV RANGE
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUMERICAL DATA
SCATTERING
TARGETS
651325* - Nuclear Properties & Reactions
A=6-19
Experimental- Nuclear Reactions & Scattering- (-1987)