Threshold photoneutron angular distribution and polarization studies of nuclei
The photoneutron method was applied to the study of (i) deuteron photodisintegration, (ii) giant magnetic dipole resonances in heavy nuclei, (iii) mechanism of radiative capture in light nuclei and (iv) isospin splitting of the giant dipole resonance in /sup 60/Ni. These studies were performed with the pulsed bremsstrahlung beam and high-resolution spectrometer available at the Argonne high-current electron linac. A threshold photoneutron polarization method was developed in order to search for the giant M1 resonance in hevy nuclei. A surprisingly small amount of M1 strength was found in /sup 208/Pb. Furthermore, the M1 strength for the 5.08-MeV excitation in /sup 17/O, the best example of a single-particle M1 resonance in nuclei, was found to be strongly quenched. In addition, the /sup 17/O(..gamma..,n/sub 0/)/sup 16/O reaction was found to provide an ideal example of the Lane-Lynn theory of radiative capture. The interplay among the three components of the theory, internal, channel and potential capture, were evident from the data. An electron beam transport system was developed which allows the bremsstrahlung to impinge on the photoneutron target on an axis perpendicular to the usual reaction plane. This system provides an accurate method for the measurement of relative angular distributions in (..gamma..,n) reactions. This system was applied to a high-accuracy measurement of the relative angular distribution for the D(..gamma..,n)H reaction. The question of isospin-splitting of the giant dipole resonance in /sup 60/Ni was studied by using the unique pico-pulse from the accelerator and the newly installed 25-m, neutron flight paths. The results provide clear evidence for the effect of isospin splitting.
- Research Organization:
- Argonne National Lab., IL
- OSTI ID:
- 6298529
- Journal Information:
- IEEE Trans. Nucl. Sci.; (United States), Vol. 28:2
- Country of Publication:
- United States
- Language:
- English
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Giant dipole resonance in sup 17 O observed with the (. gamma. , p ) reaction
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Related Subjects
COBALT 59 TARGET
PHOTONUCLEAR REACTIONS
DEUTERIUM TARGET
LEAD 208
ENERGY-LEVEL TRANSITIONS
LEAD 208 TARGET
NICKEL 60
GIANT RESONANCE
OXYGEN 17 TARGET
KNOCK-OUT REACTIONS
ANGULAR DISTRIBUTION
ENERGY LEVELS
EXPERIMENTAL DATA
GAMMA SPECTRA
ISOSPIN
M1-TRANSITIONS
NEUTRON SPECTROSCOPY
STRENGTH FUNCTIONS
DATA
DIRECT REACTIONS
DISTRIBUTION
EVEN-EVEN NUCLEI
FUNCTIONS
HEAVY NUCLEI
INFORMATION
INTERMEDIATE MASS NUCLEI
ISOTOPES
LEAD ISOTOPES
MULTIPOLE TRANSITIONS
NICKEL ISOTOPES
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
PARTICLE PROPERTIES
RESONANCE
SPECTRA
SPECTROSCOPY
STABLE ISOTOPES
TARGETS
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