Determination of the 233Pa(n,f) reaction cross section from 0.5 to 10 MeV neutron energy using the transfer reaction 232Th(3He,p)234Pa

Monte Carlo simulation of γ and fission transfer-induced probabilities using extended 𝓡-matrix theory: Application to the 237U∗ system

“…A decade ago, surrogate reactions received renewed interest in terms either of simulation [5,6] or experimental investigation (initiated by study [7]; reviewed by Ref. [8]) to infer in addition to fission, neutron-induced capture cross sections.…”

“…Early promising comparisons [1] made between extrapolated neutron fission cross sections and cross sections directly measured by neutron spectroscopy led to agreement within 10% to 20% at neutron energy above the nucleus pairing energy although exhibiting larger deviations at lower energies. Major limitations in surrogate extrapolation were promptly noticed [1,3] with the difficulty to estimate the compound nucleus formation cross section by neutron absorption, the possible influence of angular momentum differences between neutron capture and direct reactions and the validity of the Weisskopf-Ewing (WE) hypothesis related to fission decay probability spin-parity independence [4].A decade ago, surrogate reactions received renewed interest in terms either of simulation [5,6] or experimental investigation (initiated by study [7]; reviewed by Ref. [8]) to infer in addition to fission, neutron-induced capture cross sections.…”

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

“…Previous experiments [1,3,8,17] have tested the absolute surrogate reaction technique in the actinide region and have shown good agreement between known and surrogate deduced cross sections for low-equivalent neutron energies (E n = E * − S n ). However, systematic departures have been observed at higher excitation energies due to contaminants in the target [8].…”

“…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.…”