Surrogate Reaction Method Research Articles

Neutron-induced fission cross sections of short-lived actinides with the surrogate reaction method

Neutron-induced fission cross sections of short-lived actinides with the surrogate reaction method

Neutron-induced fission cross sections of short-lived actinides with the surrogate reaction method

Determination of neutron-capture cross sections of short-lived nuclei is opening the way to understand and clarify the properties of many nuclei of interest for nuclear structure physics, nuclear astrophysics and particularly for transmutation of nuclear wastes. The surrogate approach is well-recognized as a potentially very useful method to extract neutron cross sections for low-energy compound-nuclear reactions and to overcome the difficulties related to the target radioactivity. In this work we will assess where we stand on these neutron-capture cross section measurements and how we can achieve the short-lived Minor Actinides nuclei involved in the nuclear fuel cycle. The CENBG collaboration applied the surrogate method to determine the neutron-capture cross section of 233 Pa (T 1/2 = 27 d). The 233 Pa (n,γ ) cross section is then deduced from the measured gamma decay probability of 234 Pa compound nucleus formed via the surrogate 232 Th (3 He ,p) reaction channel. The obtained cross section data, covering the neutron energy range 0.1 to 1 MeV, have been compared with the predictions of the Hauser-Feshbach statistical model. The importance of establishing benchmarks is stressed for the minor actinides region. However, the lack of desired targets led us to propose recently the 174 Yb (3 He ,pγ ) reaction as a surrogate reaction for the (n,γ ) predetermined benchmark cross section of 175 Lu. An overview of the experimental setup combining gamma ray detectors such as Ge and C6D6 in coincidence with light charged particles Δ E-E Telescopes will be presented and preliminary results will be discussed.

Surrogate nuclear reaction methods for astrophysics

A brief outline of the Surrogate reaction method, an indirect approach for determining compound-nuclear reaction cross sections, is given. The assumptions introduced in the analysis of a typical Surrogate experiment are discussed and prospects for using the Surrogate method to obtain cross sections relevant to the astrophysical s-process are considered.

Compound-nuclear reaction cross sections via surrogate reactions

The surrogate reaction method is an indirect technique for determining cross sections for nuclear reactions that proceed through a well-defined compound nucleus. In this method, the same compound nucleus is produced by an alternate (“surrogate”) reaction and its decay products measured. The assumptions underlying the method are examined for the special case of 235 U( n , f ).