Energy dependence of fission probabilities induced by negative pions in Sn, Au and Bi

Cascade-exciton model analysis of mass dependence of pion-induced fission

“…It has also been observed experimentally that, in case of light target nuclei (e.g. tin) the fission cross sections increase with the energy of the pion, up to the available energy range [3]. For elements such as gold and bismuth, the fission cross sections show a saturation with the beam energy [1,3,6].…”

“…The cascade-exciton model based computer code CEM95 [10] has been used because of its good predictive power and extensive employment to calculate the nuclear fission induced by negative and positive pions [1][2][3][4][11][12][13]. Both the fission cross-sections and probabilities have been computed on the basis of cascade-exciton model of nuclear reactions [14] using this computer code.…”

“…The partial widths Γ j for the emission of a particle j (j=n, p, d, t, 3 He, 4 He) and Γ f for fission are given by the expressions;…”

“…tin) the fission cross sections increase with the energy of the pion, up to the available energy range [3]. For elements such as gold and bismuth, the fission cross sections show a saturation with the beam energy [1,3,6]. For heavy nuclei, such as uranium, a decrease of fission cross section has been observed at higher energies [2].…”

“…Since the first observation of nuclear fission, it has played a pivot role in exploring the fundamentals of nuclear physics [1][2][3][4]. It has gained prominent importance in the conventional and current nuclear applications [5], such as cascades in heavy nuclear spallation targets, which are partly propagated by pions.…”