Measurement of neutron-induced fission cross-sections for natPb, 208Pb, 197Au, natW, and 181Ta in the intermediate energy region

• Published in: Physical review. C, Nuclear physics Nuclear physics, 2004, Vol.70 (5), p.054603
• Main Authors: Smirnov, A.N., Filatov, N.P., Eismont, V.P., Condé, H., Blomgren, Jan, Prokofiev, Alexander V., Renberg, P.-U., Olsson, Nils
• Format: Article
• Language: English
• Subjects: Fysik; Kärnfysik; NATURAL SCIENCES; NATURVETENSKAP; Nuclear physics; Physics
• ISSN: 0556-2813; 1089-490X
• DOI: 10.1103/PhysRevC.70.054603

Neutron-induced fission cross-section ratios nat Pb∕ 209 Bi,  208 Pb∕ 209 Bi,  197 Au∕ 209 Bi,  nat W∕ 209 Bi,  181 Ta∕ 209 Bi, and 209 Bi∕ 238 U have been measured in the 30–180 MeV energy range using the neutron beam facility at The Svedberg Laboratory in Uppsala. The 7 Li( p , n ) reaction was employed as a neutron source. The fission fragments were detected by thin-film breakdown counters. Cross sections at specific energies were determined using unfolding techniques with respect to the excitation function and the neutron spectra, the latter obtained from recent measurements and an evaluation. The absolute fission cross sections were obtained using the standard 238 U( n , f ) cross section. The nat W( n , f ) and 181 Ta( n , f ) cross sections have been measured for the first time. The results for 209 Bi( n , f ),  nat Pb( n , f ),  208 Pb( n , f ), and 197 Au( n , f ) cross sections have been compared with available literature data. A universal easy-to-use parametrization has been suggested for all measured cross sections. The common features of subactinide neutron-induced fission cross sections are found to be similar to those of the proton-induced fission data.