Statistical and pre-equilibrium (. gamma. ,. cap alpha. ) cross sections of /sup 90/Zr and their multipolarities via the /sup 90/Zr(e,. cap alpha. ) reaction

Journal Article · Thu May 01 00:00:00 EDT 1980 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.21.1758· OSTI ID:5456755

Tamae, T; Urano, T; Hirooka, M; Sugawara, M

The (e,..cap alpha..) cross section in /sup 90/Zr has been measured at incident electron energies from 13.5 MeV to 66.5 MeV for ..cap alpha.. particles between 6.9 and 16.8 MeV. The (..gamma..,..cap alpha..) cross section was deduced from it assuming both E1 interaction and E2 interaction. The angular distribution of the (..gamma..,..cap alpha../sub 0/) cross section and an experiment using the bremsstrahlung plus electron beam make it clear that the E1 interaction is dominant over all the present energy range. The (..gamma..,..cap alpha..) cross section extracted by using E1 virtual photon spectra has a large bump above the excitation energy of 30 MeV in addition to a bump in the giant dipole resonance region. The (..gamma..,..cap alpha../sub 0/) cross section also has a bump at the giant dipole resonance which exhausts most of the (..gamma..,..cap alpha..) cross section in that region. The compound nucleus model was used successfully to explain the bump at the giant dipole resonance. The cross section above 30 MeV is discussed in terms of the pre-equilibrium ..cap alpha.. emission process combined with the quasi-deuteron model.

• Research Organization: Laboratory of Nuclear Science, Tohoku University, Mikamine, Sendai, Japan
• OSTI ID: 5456755
• Journal Information: Phys. Rev., C; (United States), Vol. 21:5
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ELECTRON REACTIONS
PHOTONUCLEAR REACTIONS
ZIRCONIUM 90 TARGET
ALPHA SPECTRA
ANGULAR DISTRIBUTION
BREMSSTRAHLUNG
COMPOUND-NUCLEUS REACTIONS
CROSS SECTIONS
DEUTERONS
DIPOLE MOMENTS
E1-TRANSITIONS
E2-TRANSITIONS
GIANT RESONANCE
MEV RANGE 10-100
PRECOMPOUND-NUCLEUS EMISSION
STATISTICAL MODELS
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
LEPTON REACTIONS
MATHEMATICAL MODELS
MEV RANGE
MULTIPOLE TRANSITIONS
NUCLEAR REACTIONS
RADIATIONS
RESONANCE
SPECTRA
TARGETS
651725* - Nuclear Properties & Reactions
A=90-149
Experimental- Nuclear Reactions & Scattering- (-1987)
651723 - Nuclear Properties & Reactions
A=90-149
Experimental- Energy Levels & Transitions- (-1987)