We compare the properties of fission induced by protons and pions.Three different methodologies are used to make this comparison.First,it is shown that pion-induced fission cross sections are not much different in mag...We compare the properties of fission induced by protons and pions.Three different methodologies are used to make this comparison.First,it is shown that pion-induced fission cross sections are not much different in magnitude from proton-induced fission cross sections at the same beam kinetic energy.Secondly,across the pion-nucleon(3,3)resonance so prominent with free nucleons,it has been observed that there is no significant change in the reaction mechanism in the case of pions.Thirdly,it is noted that an empirical expression used for evaluations of proton-induced fission cross sections is also valid for positive pion-induced fission cross sections,at least for actinide nuclei.Fission cross sections computed using a cascade-exciton model code for ^(209)Bi and ^(238)U are also compared with the experimental data available.展开更多
Fission probabilities and fission cross sections strongly depend on the mass number of the target and energy of the projectile. In this research work, a cascade-exciton model （using CEM95 computer code） has been imp...Fission probabilities and fission cross sections strongly depend on the mass number of the target and energy of the projectile. In this research work, a cascade-exciton model （using CEM95 computer code） has been implemented to observe the dependence of pion-induced fission cross sections and fission probabilities on the target mass and ratio of the level density parameter in fission to neutron emission. The analysis has been performed for both the positive and negative pions as the projectile at 80, 100 and 150 MeV energies. The computed cross sections satisfactorily reproduced the experimental findings when compared with the available experimental data in the literature. We observed a smooth dependence at 150 MeV, and a sharper dependence at 80 and 100 MeV pion energy, in the fissility region above 29.44.展开更多
文摘We compare the properties of fission induced by protons and pions.Three different methodologies are used to make this comparison.First,it is shown that pion-induced fission cross sections are not much different in magnitude from proton-induced fission cross sections at the same beam kinetic energy.Secondly,across the pion-nucleon(3,3)resonance so prominent with free nucleons,it has been observed that there is no significant change in the reaction mechanism in the case of pions.Thirdly,it is noted that an empirical expression used for evaluations of proton-induced fission cross sections is also valid for positive pion-induced fission cross sections,at least for actinide nuclei.Fission cross sections computed using a cascade-exciton model code for ^(209)Bi and ^(238)U are also compared with the experimental data available.
文摘Fission probabilities and fission cross sections strongly depend on the mass number of the target and energy of the projectile. In this research work, a cascade-exciton model （using CEM95 computer code） has been implemented to observe the dependence of pion-induced fission cross sections and fission probabilities on the target mass and ratio of the level density parameter in fission to neutron emission. The analysis has been performed for both the positive and negative pions as the projectile at 80, 100 and 150 MeV energies. The computed cross sections satisfactorily reproduced the experimental findings when compared with the available experimental data in the literature. We observed a smooth dependence at 150 MeV, and a sharper dependence at 80 and 100 MeV pion energy, in the fissility region above 29.44.
