Heavy-ion Coulomb excitation and photon decay of the giant dipole resonance in sup 208 Pb

Journal Article · Thu Mar 01 00:00:00 EST 1990 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.41.920· OSTI ID:6848564

Beene, J R; Bertrand, F E; Horen, D J; Auble, R L; Burks, B L; Gomez del Campo, J; Halbert, M L; Sayer, R O ^[1]; Mittig, W; Schutz, Y ^[2]; Barrette, J; Alamanos, N; Auger, F; Fernandez, B; Gillibert, A ^[3]; Haas, B; Vivien, J P ^[4]

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1. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (USA)
2. Grand Accelerateur National d'Ions Lourds, 14021 Caen CEDEX, France (FR)
3. Departement de Physique Nucleaire/Basse Energie, Centre d'Etudes Nucleaires de Saclay, 91191 Gif-sur-Yvette CEDEX, France (FR)
4. Centre de Recherches Nucleaires, 67037 Strasbourg CEDEX, France (FR)

The excitation and electromagnetic decay of the giant resonance region (8--15 MeV) in {sup 208}Pb have been measured with the {sup 208}Pb({sup 17}O,{sup 17}O{prime}) reaction at 84 MeV/nucleon. The study of coincidences between scattered {sup 17}O ions and photon decays to the {sup 208}Pb ground state, including angular correlations, serves to isolate the isovector giant dipole resonance and enable us to investigate the mechanisms of its excitation and decay in detail. The angular correlations and yields are accounted for quantitatively by a pure Coulomb excitation model of the reaction process. The distribution in energy of the ground-state photon decay cross section is well described by an approximate application of the multistep theory of nuclear reactions. The photon coincidence measurements enable us to extract the differential cross sections for the 10.6-MeV giant quadrupole and 13.9-MeV monopole resonances with low uncertainty. An analysis of the Coulomb-nuclear interference for the 10.6-MeV excitation indicates that the ratio of neutron to proton matrix elements, {ital M}{sub {ital n}}/{ital M}{sub {ital p}}, is 1.7{plus minus}0.4, consistent with a predominantly isoscalar character for the giant quadrupole resonance.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6848564
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Vol. 41:3; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
LEAD 208
GAMMA DECAY
GIANT RESONANCE
LEAD 208 TARGET
OXYGEN 17 REACTIONS
INELASTIC SCATTERING
ANGULAR CORRELATION
COINCIDENCE METHODS
COULOMB EXCITATION
DIFFERENTIAL CROSS SECTIONS
DIPOLES
DISTORTED WAVE THEORY
E1-TRANSITIONS
EXPERIMENTAL DATA
MONOPOLES
MULTIPOLARITY
QUADRUPOLES
CHARGED-PARTICLE REACTIONS
CORRELATIONS
COUNTING TECHNIQUES
CROSS SECTIONS
DATA
DECAY
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EXCITATION
HEAVY ION REACTIONS
HEAVY NUCLEI
INFORMATION
ISOTOPES
LEAD ISOTOPES
MULTIPOLE TRANSITIONS
MULTIPOLES
NUCLEAR DECAY
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
RESONANCE
SCATTERING
STABLE ISOTOPES
TARGETS
651920* - Nuclear Properties & Reactions
A=190-219
Experimental