Determination of the 233Pa(n, γ) capture cross section up to neutron energies of 1 MeV using the transfer reaction 232Th(3He, p)234Pa∗

Neutron-capture cross sections from indirect measurements

“…The two measurements are in good agreement with each other for [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] MeV and the averaged cross section agrees well with previous, direct, measurements in the 5-10 MeV range; it is somewhat higher (by less than 20%) than those at about 15 MeV. The ratio measurement does not, and is not expected to, produce highly-accurate fission results at low energies (< 5 MeV here), due to the underlying Weisskopf-Ewing assumption.…”

“…More recently, a French group has carried out surrogate experiments at the Institut de Physique Nucléaire (IPN) in Orsay to determine cross sections for neutron-induced reactions on several minor actinide nuclei relevant to the thorium-uranium fuel cycle and the transmutation of nuclear waste [9][10][11]. The transfer reactions 232 Th( 3 He,x) and 243 Am( 3 He,x), with x=α,t,d,p, were employed to obtain (n,f) and (n,γ) cross sections for Th and Pa targets [9,10] and (n,f) cross sections for Cm and Am targets [11], respectively.…”

“…The transfer reactions 232 Th( 3 He,x) and 243 Am( 3 He,x), with x=α,t,d,p, were employed to obtain (n,f) and (n,γ) cross sections for Th and Pa targets [9,10] and (n,f) cross sections for Cm and Am targets [11], respectively. The analyses assumed that the Weisskopf-Ewing approximation is valid.…”

Relative U235(n,γ) and (Allmond1, Bernstein2, Beausang3 et al. 2009Phys. Rev. C370200View full textAdd to dashboardCite

“…The surrogate reaction technique, first applied in 1970 [1], has recently been the subject of intensive investigation [2][3][4][5][6][7][8][9][10][11][12][13] in order to establish its use and accuracy. The surrogate method (absolute [1] and ratio [4]) has been employed to circumvent technical challenges presented by the fabrication of unstable radioactive targets and the production of high-flux neutron beams.…”

Surrogate reactions: the Weisskopf-Ewing approximation and its limitations

“…The Surrogate approach was first employed in the 1970s [1] to estimate neutron-induced fission cross sections from transfer reactions. More recently, the Surrogate method has attracted renewed attention: additional fission experiments have been carried out [2][3][4], new approximation schemes [5][6][7][8] and refinements [9] of the method have been studied, and applications to other mass regions are being considered [10]. Here we discuss some of the limitations of the current approximations and outline some recommendations for future theory and experimental developments.…”