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

Abstract

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.

Authors:
; ;  [1]
  1. Kharkov Institute for Physics and Technology (Ukraine)
Publication Date:
OSTI Identifier:
21075880
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Atomic Nuclei; Journal Volume: 70; Journal Issue: 5; Other Information: DOI: 10.1134/S1063778807050055; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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

Citation Formats

Afanas'ev, S. N., E-mail: afanserg@kipt.kharkov.ua, Gorbenko, E. S., and Khodyachikh, A. F.. Investigation of the reaction mechanism for the four-particle photodisintegration of a carbon nucleus. United States: N. p., 2007. Web. doi:10.1134/S1063778807050055.
Afanas'ev, S. N., E-mail: afanserg@kipt.kharkov.ua, Gorbenko, E. S., & Khodyachikh, A. F.. Investigation of the reaction mechanism for the four-particle photodisintegration of a carbon nucleus. United States. doi:10.1134/S1063778807050055.
Afanas'ev, S. N., E-mail: afanserg@kipt.kharkov.ua, Gorbenko, E. S., and Khodyachikh, A. F.. Tue . "Investigation of the reaction mechanism for the four-particle photodisintegration of a carbon nucleus". United States. doi:10.1134/S1063778807050055.
@article{osti_21075880,
title = {Investigation of the reaction mechanism for the four-particle photodisintegration of a carbon nucleus},
author = {Afanas'ev, S. N., E-mail: afanserg@kipt.kharkov.ua and Gorbenko, E. S. and Khodyachikh, A. F.},
abstractNote = {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.},
doi = {10.1134/S1063778807050055},
journal = {Physics of Atomic Nuclei},
number = 5,
volume = 70,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}