Polarized deuteron radiative capture studies of the giant dipole resonance of /sup 16/O

Thesis/Dissertation · Sat Jan 01 00:00:00 EST 1983

OSTI ID:6129235

Gossett, C A

The nature of the intermediate structure observed in the giant dipole resonance of /sup 16/O is investigated through measurement of the radiative capture of polarized deuterons. The angular distributions of the cross section and the four analyzing powers, iT/sub 11/, T/sub 20/, T/sub 21/, and T/sub 22/ for the /sup 14/N(d vector, ..gamma../sub 0/)/sup 16/O reaction are measured for incident deuteron energies in the range 1.7 to 5.5 MeV, corresponding to excitation energies in /sup 16/O of 21.8 to 25.4 MeV. At the peak of the predominant structure in the reaction, a model-independent extraction of the transition matrix elements confirms that the radiation is primarily (approx.85%) isospin forbidden El. The expansion coefficients extracted from the expansion of the angular distributions in terms of Legendre polynomials and associated Legendre functions exhibit strongly fluctuating energy dependence. The energy location and width of this structure is found to be correlated with the structure observed in the nucleon photoabsorption cross section. However, previous interpretations of the intermediate structure in the giant dipole resonance of /sup 16/O as seen in the /sup 15/N(p,..gamma../sub 0/)/sup 16/O and /sup 16/O(..gamma..,n/sub 0/)/sup 15/O reactions are inadequate to explain the energy dependence of the radiative deuteron capture observables. The structure observed in the /sup 14/N(d vector, ..gamma../sub 0/)/sup 16/O reaction is examined in the context of the doorway-state model of Feshback, Kerman and Lemmer. In addition, the experimental results from studies of /sup 16/O with the (p vector, ..gamma../sub 0/), (..cap alpha.., ..gamma../sub 0/), and (/sup 3/He, ..gamma../sub 0/) reactions are combined with the (d vector, ..gamma../sub 0/) measurements in order to obtain a self-consistent description of the reaction mechanism responsible for the intermediate structure in /sup 16/O.

• Research Organization: Wisconsin Univ., Madison (USA)
• OSTI ID: 6129235
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DEUTERON REACTIONS
CAPTURE
NITROGEN 14 TARGET
OXYGEN 16
GIANT RESONANCE
ANGULAR DISTRIBUTION
ENERGY LEVELS
GAMMA RADIATION
MEV RANGE 01-10
POLARIZED BEAMS
BEAMS
CHARGED-PARTICLE REACTIONS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ENERGY RANGE
EVEN-EVEN NUCLEI
IONIZING RADIATIONS
ISOTOPES
LIGHT NUCLEI
MEV RANGE
NUCLEAR REACTIONS
NUCLEI
OXYGEN ISOTOPES
RADIATIONS
RESONANCE
STABLE ISOTOPES
TARGETS
651325* - Nuclear Properties & Reactions
A=6-19
Experimental- Nuclear Reactions & Scattering- (-1987)
651323 - Nuclear Properties & Reactions
A=6-19
Experimental- Energy Levels & Transitions- (-1987)