Investigation of the reaction mechanism for the four-particle photodisintegration of a carbon nucleus

Journal Article · Tue May 15 04:00:00 EDT 2007 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778807050055· OSTI ID:21075880

Gorbenko, E S; Khodyachikh, A F ^[1]

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1. Kharkov Institute for Physics and Technology (Ukraine)

The four-particle photodisintegration of a carbon nucleus in the reactions {sup 12}C({gamma}, p){sup 3}H2{alpha} and {sup 12}C({gamma}, n){sup 3}H2{alpha} is investigated by a method that employs a diffusion chamber in a magnetic field. It is shown that these reactions proceed according a sequential-type scheme: excited states of {sup 11}B and {sup 11}C nuclei decay to weakly excited states of {sup 8}Be, {sup 7}Li, and {sup 7}Be nuclei. It is concluded that nucleons are knocked out from the s shell. In the excitation curve for the 2{alpha} system in the reaction {sup 12}C({gamma}, p){sup 3}H2{alpha}, a resonance is found between the maxima corresponding to the ground and the first excited state of the {sup 8}Be nucleus, and this resonance is identified as a ghost anomaly. The branching fractions of the decay modes are determined. The angular distributions of nucleons in the reaction c.m. frame are measured. The energy dependence of the asymmetry coefficient for the angular distributions is obtained. A fast increase in this coefficient is observed in the energy range 38-40 MeV. It is concluded that the asymmetry coefficient depends on the excitation energy of the final nucleus in the region of intermediate photon energies.

• OSTI ID: 21075880
• Journal Information: Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 5 Vol. 70; ISSN 1063-7788; ISSN PANUEO
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ASYMMETRY COEFFICIENTS
BERYLLIUM 7
BERYLLIUM 8
BORON 11
BRANCHING RATIO
CARBON
CARBON 11
CARBON 12
DIFFUSION CHAMBERS
ENERGY DEPENDENCE
EXCITATION
EXCITED STATES
LITHIUM 7
MEV RANGE 10-100
NUCLEAR DECAY
NUCLEONS
PHOTONS
PHOTONUCLEAR REACTIONS
REACTION KINETICS