Independent isomeric yield ratio ofPm148in fission of the moderately excited

D.C. Aumann

¹

,

W. Gückel

²

,

E. Nirschl

³

et al.

Isomeric yield ratios of fission products in the system of 24 MeV proton-induced fission of238U

“…The procedures of (1) and (2) have been made for thermal-neutron fission of actinides and sawtooth behavior of angular momentum was indicated [5]. The procedures (3) and (4) give the angular momentum of specific nuclide and indicate the tendency different from those found in the methods (1) and (2) [8,[11][12][13]. The method (3) is used only to eveneven nuclides.…”

“…The angular momentum of fission products is considered to be determined by the following factors; the excitation energy and the spin of fissioning nucleus [14], the mass splitting [8], the charge distribution [ 11,15], the fragment kinetic energy [ 12], the atomic and neutron numbers or their closed shell effect [16,17], the internal excitation (or deformation) energy of fragments [12,13,18,19], and so on. Until now, it has been understood that the isomeric yield ratio is related to the angular momentum of primary fragment.…”

Statistical study of the prompt-fission γ -ray spectrum for U238(n, f ) in the fast-neutron region

“…Prompt-fission γ -ray spectra integrate a large amount of information about the fission process. Measurements, namely, allow further insight into angular momentum generation at scission [2,3]. In addition, they are expected to lead to a better understanding of the competition between neutron and γ emission [4][5][6], and thereby possibly contribute to investigate the mechanism of excitation energy sorting between the two fission partners [7][8][9].…”

Influence of collective rotational degrees of freedom in medium energy fission

“…The K~ shown in Table 4, for the asymmetric split involving mass 134, is lower than expected for the symmetric-split [19] and is well within the probable limits for an asymmetric-split [20,21]. In order to test the present approach further, Jrms of the fragments corresponding to 14SPm in e-induced fission of 232Th at various excitation energies were also deduced for comparison with the available experimental data [22]. It was seen in this case that the fragment Jrms increases from ~ 14 to 17 h for increase in the excitation energy from 20.8 to 36.2 MeV in accordance with the experimental observations [22].…”

“…In order to test the present approach further, Jrms of the fragments corresponding to 14SPm in e-induced fission of 232Th at various excitation energies were also deduced for comparison with the available experimental data [22]. It was seen in this case that the fragment Jrms increases from ~ 14 to 17 h for increase in the excitation energy from 20.8 to 36.2 MeV in accordance with the experimental observations [22]. Figure 1 shows the calculated variation in the fragment Jrms for 134Te and 148Pm with increasing excitation energy (E*) and initial average angular momenta ((J)) of the compound nucleus 236U.…”