The fission angular distributions and the angular dependence of fragment spins in ter-ms of preequilibrium fission model are calculated.The results show strong effects of preequil-ibrium fission on both angular distri...The fission angular distributions and the angular dependence of fragment spins in ter-ms of preequilibrium fission model are calculated.The results show strong effects of preequil-ibrium fission on both angular distributions and angular dependence of fragment spins.展开更多
A discussion on double differential cross section of nucleons based onanisotropic intranuclear scattering is presented since the anisotropic behavior ofnucleon-nucleon scattering becomes strong with increasing inciden...A discussion on double differential cross section of nucleons based onanisotropic intranuclear scattering is presented since the anisotropic behavior ofnucleon-nucleon scattering becomes strong with increasing incident energy but in pre-vious theories the isotropic picture is used.The calculated results indicate that theanisotropic effect slightly improves the agreement with the experimental data.展开更多
Formulations of double differential cross sections of light composite particleconsidering (1,m) and (2,m) pickup type reactions simultaneously for semi-classicalmulti-step compound and direct processes are presented.T...Formulations of double differential cross sections of light composite particleconsidering (1,m) and (2,m) pickup type reactions simultaneously for semi-classicalmulti-step compound and direct processes are presented.The calculated results of crosssections,spectra,and double differential cross sections indicate that generally the con-tributions of the (2,m) pickup type reactions are about 15%-25% when the incident en-ergies are below 50 MeV but can become dominant when the incident energies areabove 50 MeV in some region of the outgoing energies and angles.The forward tenden-cy of the calculated angular distributions by (2,m) configuration is weaker than those by(1,m) configuration.For the reactions of outgoing composite particle with higher inci-dent energy,the multi-step direct process must be considered.展开更多
-The energy spectrum and angular distributions of protons from <sup>93</sup>Nb（n,xp）reactions are measured by means of the USTC（University of Science and Technologyof China）multitelescope system.The to...-The energy spectrum and angular distributions of protons from <sup>93</sup>Nb（n,xp）reactions are measured by means of the USTC（University of Science and Technologyof China）multitelescope system.The total proton production cross sections are in fairagreement with the results of other groups.The energy spectrum is well explained by thesum of the spectra calculated on the basis of the preequilibrium and the H-F theories.Deviations from the previous measurement at the high energy end of the angle-inte-grated proton spectrum are found.The angular distributions which show a stronglyenergy-dependent forward-backward asymmetry are in fair agreement with thephenomenological model of Kalbach-Mann.展开更多
After considering the transitions from P to Q chains,a new formula for the multistepcompound reaction double differential cross-section is given.The new formula includes theMSC’s and CN’s contributions.The n-step(n...After considering the transitions from P to Q chains,a new formula for the multistepcompound reaction double differential cross-section is given.The new formula includes theMSC’s and CN’s contributions.The n-step(n】1)multistep direct reaction double differentialcross section is expressed by two one-step double differential cross-sections.展开更多
文摘The fission angular distributions and the angular dependence of fragment spins in ter-ms of preequilibrium fission model are calculated.The results show strong effects of preequil-ibrium fission on both angular distributions and angular dependence of fragment spins.
文摘A discussion on double differential cross section of nucleons based onanisotropic intranuclear scattering is presented since the anisotropic behavior ofnucleon-nucleon scattering becomes strong with increasing incident energy but in pre-vious theories the isotropic picture is used.The calculated results indicate that theanisotropic effect slightly improves the agreement with the experimental data.
文摘Formulations of double differential cross sections of light composite particleconsidering (1,m) and (2,m) pickup type reactions simultaneously for semi-classicalmulti-step compound and direct processes are presented.The calculated results of crosssections,spectra,and double differential cross sections indicate that generally the con-tributions of the (2,m) pickup type reactions are about 15%-25% when the incident en-ergies are below 50 MeV but can become dominant when the incident energies areabove 50 MeV in some region of the outgoing energies and angles.The forward tenden-cy of the calculated angular distributions by (2,m) configuration is weaker than those by(1,m) configuration.For the reactions of outgoing composite particle with higher inci-dent energy,the multi-step direct process must be considered.
基金The project supported in part by National Natural Science Foundation of China and CNNC
文摘-The energy spectrum and angular distributions of protons from <sup>93</sup>Nb（n,xp）reactions are measured by means of the USTC（University of Science and Technologyof China）multitelescope system.The total proton production cross sections are in fairagreement with the results of other groups.The energy spectrum is well explained by thesum of the spectra calculated on the basis of the preequilibrium and the H-F theories.Deviations from the previous measurement at the high energy end of the angle-inte-grated proton spectrum are found.The angular distributions which show a stronglyenergy-dependent forward-backward asymmetry are in fair agreement with thephenomenological model of Kalbach-Mann.
基金The project partly supported by the National Natural Science Foundation of China (19475067)the Nuclear Industry Foundation of China (194A01010)
文摘After considering the transitions from P to Q chains,a new formula for the multistepcompound reaction double differential cross-section is given.The new formula includes theMSC’s and CN’s contributions.The n-step(n】1)multistep direct reaction double differentialcross section is expressed by two one-step double differential cross-sections.
