Absolute photofission cross section of sup 197 Au, @Pb, sup 209 Bi, sup 232 Th, sup 238 U, and sup 235 U nuclei by 69-MeV monochromatic and polarized photons

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

DOI:https://doi.org/10.1103/PhysRevC.44.354· OSTI ID:5462995

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

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

Absolute cross-section measurements for the photofission reactions of {sup 197}Au, {sup nat}Pb, {sup 209}Bi, {sup 232}Th, {sup 238}U, and {sup 235}U nuclei have been performed at an incident photon energy of 69 MeV using monochromatic and polarized photon beams and dielectric fission-track detectors. Nuclear fissility values have been obtained and results are in agreement with those from other laboratories, although in some cases discrepancies are observed between one other. For nuclei in the region of the actinides the fissility result is {approx gt}0.4, while for Au, Pb, and Bi nuclei it only is {similar to}10{sup {minus}3}--10{sup {minus}2}. Results have been interpreted in terms of the primary Levinger's quasideuteron nuclear photoabsorption followed by a mechanism of evaporation-fission competition for the excited nuclei. Shell effects have been taken into account, and they are clearly manifested when fissility is evaluated. The influence of photon polarization on photofission of {sup 238}U also has been investigated, and results have shown isotropy in the fragment azimuthal distribution.

• OSTI ID: 5462995
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Vol. 44:1; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BISMUTH 209 TARGET
PHOTOFISSION
GOLD 197 TARGET
LEAD
THORIUM 232 TARGET
URANIUM 235 TARGET
URANIUM 238 TARGET
ANGULAR DISTRIBUTION
CROSS SECTIONS
EXPERIMENTAL DATA
FISSION FRAGMENTS
LEVINGER-BETHE THEORY
MEV RANGE 10-100
MONOCHROMATIC RADIATION
POLARIZED BEAMS
BEAMS
DATA
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY RANGE
FISSION
INFORMATION
METALS
MEV RANGE
NUCLEAR FRAGMENTS
NUCLEAR REACTIONS
NUMERICAL DATA
PHOTONUCLEAR REACTIONS
RADIATIONS
TARGETS
651920* - Nuclear Properties & Reactions
A=190-219
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652020 - Nuclear Properties & Reactions
A=220 & above
Experimental