Excitation functions and isomeric cross section ratios of the {sup 63}Cu({ital n},{alpha}){sup 60}Co{sup {ital m},}{ital g}, {sup 65}Cu({ital n},{alpha}){sup 62}Co{sup {ital m},}{ital g}, and

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.49.1525· OSTI ID:142675

Cserpak, F; Sudar, S; Csikai, J; Qaim, S M ^[1]

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

Excitation functions were measured for the {sup 63}Cu({ital n},{alpha}){sup 60}Co{sup {ital m}}, {sup 65}Cu({ital n},{alpha}){sup 62}Co{sup {ital m}}, and {sup 65}Cu({ital n},{alpha}){sup 62}Co{sup {ital g}} reactions over the neutron energy range of 6.3 to 14.8 MeV. Use was made of the activation technique in combination with high resolution {gamma}-ray spectroscopy. The nuetrons were produced via the {sup 2}H({ital d},{ital n}){sup 3}He reaction using a deuterium gas target at a variable energy compact cyclotron ({ital E}{sub {ital n}}=6.3--11.9 MeV) and via the {sup 3}H({ital d},{ital n}){sup 4}He reaction using a solid Ti-T target at a neutron generator ({ital E}{sub {ital n}}=13.7--14.8 MeV). From the available experimental data isomeric cross section ratios were determined for the isomeric pair {sup 60}Co{sup {ital m},}{ital g} in {sup 63}Cu({ital n},{alpha}) and {sup 60}Ni({ital n},{ital p}) reactions, and for the pair {sup 62}Co{sup {ital m},}{ital g} in the {sup 65}Cu({ital n},{alpha}) reaction. Statistical model calculations taking into account precompound effects were performed for the formation of both the isomeric and ground states of the products. The calculational results on the total ({ital n},{ital p}) and ({ital n},{alpha}) cross sections agree well with the experimental data; in the case of isomeric states, however, some deviations occur. The experimental isomeric cross section ratios are reproduced only approximately by the calculation; at 15 MeV the spin distribution of the level density has a significant effect on the calculation. For low-lying levels the isomeric cross section ratio depends strongly on the spins of the levels involved and not on their excitation energies. At a given neutron energy the population of the higher spin isomer appears to be higher in the ({ital n},{alpha}) process than in the ({ital n},{ital p}) reaction.

• OSTI ID: 142675
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 3 Vol. 49; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ALPHA PARTICLES
COBALT 62
COPPER 63 TARGET
COPPER 65 TARGET
CROSS SECTIONS
EXCITATION FUNCTIONS
GAMMA SPECTROSCOPY
ISOMERIC NUCLEI
MEV RANGE 01-10
MEV RANGE 10-100
NEUTRON REACTIONS
TRANSFER REACTIONS