Combined model of photonucleon reactions

Journal Article · Sat Jan 15 00:00:00 EST 2011 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778811010054· OSTI ID:22029962

Ishkhanov, B S

A combination of the semimicroscopic, exciton, and evaporation models is used to describe photonucleon reactions induced in medium-mass and heavy nuclei by photons of energy below the mesonproduction threshold. Two mechanisms of the photoexcitation of nuclei are considered. These are the formation of a giant dipole resonance (GDR) at energies in the range E{sub {gamma}} Less-Than-Or-Equivalent-To 30 MeV and quasideuteron photoabsorption, which is dominant at energies in the region E{sub {gamma}} Greater-Than-Or-Equivalent-To 40 MeV. The densities of particle-hole states appearing in the exciton model are calculated on the basis of the Fermi gas model. Our combined model takes into account the multiparticle emission of preequilibrium particles. The influence of isospin conservation and collective phenomena on photonucleon emission by giant dipole resonances is considered. The combined model is used to describe cross sections for photonucleon reactions proceeding on the {sup 40,48}Ca, {sup 90}Zr, {sup 139}La, {sup 142}Nd, and {sup 181}Ta nuclei, as well as difference (E{sub {gamma}max} = 85-55 MeV) bremsstrahlung photoneutron spectra for the {sup 63}Cu, {sup 115}In, {sup 118}Sn, {sup 181}Ta, {sup 207}Pb, {sup 209}Bi, and {sup 235}U nuclei and bremsstrahlung photoproton spectra for the {sup 90}Zr nucleus at the energies of E{sub {gamma}max} = 22, 25, and 34 MeV.

• OSTI ID: 22029962
• Journal Information: Physics of Atomic Nuclei, Vol. 74, Issue 1; Other Information: Copyright (c) 2011 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7788
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BISMUTH 209
CALCIUM 48 TARGET
COPPER 63
CROSS SECTIONS
DIPOLES
EVAPORATION MODEL
EXCITON MODEL
FERMI GAS MODEL
INDIUM 115
LANTHANUM 139 TARGET
LEAD 207
MEV RANGE
NEODYMIUM 142 TARGET
PARTICLE-HOLE MODEL
PHOTONUCLEAR REACTIONS
TANTALUM 181 TARGET
TIN 118
URANIUM 235
ZIRCONIUM 90 TARGET