Isomeric cross-section ratio for the formation of {sup 58}Co{sup {ital m},{ital g}} in neutron, proton, deuteron, and alpha-particle induced reactions in the energy region up to 25 MeV

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.53.2885· OSTI ID:284773

Sudar, S; Qaim, S M ^[1]

---

1. Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany)

Excitation functions were determined for {sup 58}Fe({ital p},{ital n}){sup 58}Co{sup {ital m}}, {sup nat}Fe({ital d},{ital xn}){sup 58}Co{sup {ital m}}, {sup 55}Mn({alpha},{ital n}){sup 58}Co{sup {ital m}}, and {sup 59}Co({ital n},2{ital n}){sup 58}Co{sup {ital m}} reactions from the respective thresholds to 14.12 MeV in work with protons, 12.97 MeV with deuterons, 13 MeV with neutrons, and 25.52 MeV with alpha particles. The radioactivity of the activation product {sup 58}Co{sup {ital m}}({ital T}{sub 1/2}=9.15 h) was determined by high resolution {gamma}-ray and x-ray spectrometry. Using the present {sigma}{sub {ital m}} results and the ({sigma}{sub {ital m}}+{sigma}{sub {ital g}}) data reported earlier, the isomeric cross-section ratio {sigma}{sub {ital m}}/({sigma}{sub {ital m}}+{sigma}{sub {ital g}}) was determined for each reaction. Statistical model calculations taking into account the precompound effects were performed for the above-mentioned four reactions as well as for the {sup 58}Ni({ital n},{ital p}){sup 58}Co{sup {ital m},{ital g}} process. A consistent set of model parameters was used. The isomeric cross-section ratio for the pair {sup 58}Co{sup {ital m},{ital g}} strongly depends on the level scheme and branching ratios of the known levels of {sup 58}Co. Different reactions produced different angular momentum distributions of the compound nucleus, resulting in different isomeric cross-section ratio at the same excitation of the compound nucleus. The ratio was found to be relatively high for target nuclei with high spin values. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 284773
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 6 Vol. 53; ISSN PRVCAN; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ALPHA REACTIONS
ANGULAR DISTRIBUTION
BRANCHING RATIO
COBALT 59 TARGET
CROSS SECTIONS
DEUTERON REACTIONS
EXCITATION
GAMMA SPECTROMETERS
IRON 58 TARGET
ISOMERIC NUCLEI
MANGANESE 55 TARGET
MEV RANGE 10-100
NEUTRON REACTIONS
PROTON REACTIONS
RADIOACTIVITY
STATISTICAL MODELS
X-RAY SPECTROMETERS