Fission of complex nuclei induced by 52-MeV monochromatic and polarized photons

Journal Article · Tue Oct 01 00:00:00 EDT 1991 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.44.1683· OSTI ID:5099269

Tavares, O A.P.; Terranova, M L ^[1]; Casano, L; D'Angelo, A; Moricciani, D; Schaerf, C ^[2]; Babusci, D ^[3]; Girolami, B ^[4]; Martins, J B; Moreira, E L; Vieira, J L ^[5]

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1. Dipartimento di Scienze e Tecnologie Chimiche, II Universita di Roma Tor Vergata,'' Via E. Carnevale, 00173 Roma (Italy) Istituto Nazionale di Fisica Nucleare, Sezione di Roma 2, Roma (Italy)
2. Dipartimento di Fisica, II Universita di Roma Tor Vergata,'' Via E. Carnevale, 00173 Roma (Italy) Istituto Nazionale di Fisica Nucleare, Sezione di Roma 2, Roma (Italy)
3. Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Casella Postale 13, 00044 Frascati (Rm) (Italy)
4. Laboratorio di Fisica dell'Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Roma (Italy) Istituto Nazionale di Fisica Nucleare, Sezione Sanita, Roma (Italy)
5. Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150, 22290 Rio de Janeiro (Brazil)

Experimental fissility data from photofission reactions of {sup 232}Th, {sup 238}U, and {sup 235}U nuclei at 52 MeV have been obtained using monochromatic and polarized photon beams and dielectric fission-track detectors. These data, along with literature data for {sup 237}Np, {sup 235,238}U, {sup 232}Th, {sup 209}Bi, {sup 208}Pb, and {sup 174}Yb nuclei have been analyzed within the framework of a simple two-step model for photofission reactions, i.e., absorption of the incident photon by a neutron-proton pair followed by an evaporation-fission competition mechanism for the excited nucleus. For nuclei in the Ta-Np region the trend of calculated fissilities clearly shows shell effects in the vicinity of {sup 208}Pb. In the case of {sup 238}U the effect of photon polarization on fission direction has also been studied, and isotropy was observed in the fragment azimuthal distribution.

• OSTI ID: 5099269
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Vol. 44:4; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
THORIUM 235
PHOTOFISSION
URANIUM 235 TARGET
URANIUM 238 TARGET
ANGULAR DISTRIBUTION
CROSS SECTIONS
EXPERIMENTAL DATA
MEV RANGE 10-100
POLARIZED BEAMS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
BEAMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DATA
DISTRIBUTION
ENERGY RANGE
EVEN-ODD NUCLEI
FISSION
HEAVY NUCLEI
INFORMATION
ISOTOPES
MEV RANGE
MINUTES LIVING RADIOISOTOPES
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
PHOTONUCLEAR REACTIONS
RADIOISOTOPES
TARGETS
THORIUM ISOTOPES
652020* - Nuclear Properties & Reactions
A=220 & above
Experimental