The giant dipole resonance and the deformation of highly excited nuclei

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6453492

Snover, K A

A great deal has been learned in the past few years about the shapes of highly excited nuclei through studies of the giant dipole resonance in heavy ion fusion-evaporation reactions. At bombarding energies less than or equal to 5-7 MeV per nucleon, statistical decay of the GDR dominates the ..gamma..-emission spectrum for E..gamma.. = 5 - 30 MeV, and detailed spectrum shape analyses have been performed for many different reactions populating nuclei over most of the periodic table and corresponding to nuclear spins I = 0-50/h bar/ and temperatures T = 1-2 MeV. These temperatures span the interesting range from shell-dominated shapes to liquid-drop dominated shapes, and the interplay of these effects as a function of spin, temperature and nuclear species is expected to lead to a variety of nuclear shapes and shape changes. On the other hand, because nuclei consists of a small number of particles, shape fluctuations are very important, and tend to obscure the nuclear shapes expected in mean-field calculations. In this paper I focus on two objectives: A general assessment of our overall understanding of the properties of the GDR in highly excited nuclei and the scope and limitations of GDR spectrum shape analyses, and a discussion of the importance of angular distribution measurements and their implications in a specific case - oblate, rapidly rotating nuclei with mass A approx. 40. 20 refs., 3 figs.

• Research Organization: Washington Univ., Seattle (USA). Nuclear Physics Lab.
• DOE Contract Number: AC06-81ER40048
• OSTI ID: 6453492
• Report Number(s): DOE/ER/40048-216-L8; CONF-880639-8; ON: DE89008215
• Country of Publication: United States
• Language: English

Related Subjects

651420* -- Nuclear Properties & Reactions
A=20-38
Experimental
653001 -- Nuclear Theory-- Nuclear Structure
Moments
Spin
& Models
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALUMINIUM 27 TARGET
ANGULAR DISTRIBUTION
CHARGED-PARTICLE REACTIONS
DEFORMATION
DEFORMED NUCLEI
DISTRIBUTION
GIANT RESONANCE
HEAVY ION REACTIONS
NUCLEAR DEFORMATION
NUCLEAR REACTIONS
NUCLEI
OXYGEN 18 REACTIONS
RESONANCE
TARGETS
TEMPERATURE DEPENDENCE