-ray strength function method; A Way from photoneutron emission to radiative neutron capture

Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Yamagata, Tamio*; Iwamoto, Chihiro*; Goriely, S.*; Daoutidis, I.*; Toyokawa, Hiroyuki*; Harada, Hideo   ; Kitatani, Fumito  ; Iwamoto, Nobuyuki  ; Lui, Y. W.*; Arteaga, D. P.*; Hilaire, S.*; Koning, A. J.*

Radiative neutron capture cross section are of direct relevance for the synthesis of heavy elements referred to as the s-process and the r-process in nuclear astrophysics and constitute basic data in the field of nuclear engineering. The surrogate reaction technique is in active use to indirectly determine radiative neutron capture cross sections for unstable nuclei. We have devised an indirect method alternative to the surrogate reaction technique on the basis of the -ray strength function (-SF), a nuclear statistical quantity that interconnects photoneutron emission and radiative neutron capture in Hauser-Feshbach model calculation. The primary strength of the -SF is low-energy E1 strength in the tail of GDR. We outline the -SF method and show application of the method to Zr, Pd and Sn isotopes. In the application of the -SF method, it is important to use -SF, which incorporates extra strengths of PDR and/or M1 resonance emerging around neutron threshold.