Cumulative fission product yields from monoenergetic-neutron-induced fission in 238U

Mass distribution in the bremsstrahlung-induced fission of 232Th, 238U and 240Pu

“…The decreasing trend of the nuclear structure effects with an increase in excitation energy is also clear from the figure of mass yield data based on physical measurements in the bremsstrahlung-induced fission of 240 Pu [75]. This is supported by the decreasing trend of the nuclear structure effects with increasing neutron energy in various mono-energetic neutron-induced fissions of 232 Th [38][39][40][41][42], 233 U [43], 235 U [44,45], 238 U [45][46][47][48] and 239 Pu [38,51]. In the absence of the even-odd effect [97] in the odd-Z fissioning system, a decreasing trend of shell effect with an increase in excitation energy can be seen only in the mono-energetic neutron-induced fission of 237 Np [49,50].…”

“…Thus the higher yields of fission products around mass numbers 133-135 and 143-145 as well as average mass of 138 ± 1 with fixed charge of 54 ± 1 are expected from both shell effects [99] and the N/Z [52][53][54] point of view. However, shell and pairing effects decrease with an increase in excitation energy for both neutron- [38][39][40][41][42][43][44][45][46][47][48]51,91] and bremsstrahlung-induced [89,90] fission of actinides. In order to examine the role of excitation energy, the yields of fission products in the 10 MeV bremsstrahlung-induced fission of 232 Th and 238 U and at higher energies from Refs.…”

“…peak-to-valley (P /V ) ratio) in the bremsstrahlung-induced fission of 232 Th [55][56][57][58][59][60]89] and 238 U [61][62][63][64][65][66][67][68][69][70][71][72][73][74]90] are given in Tables 4 and 5, respectively. Similarly the yield of fission products in the peak position, the symmetric region and their ratio (i.e., peak-to-valley (P /V ) ratio) in the mono-energetic neutron-induced fission of 232 Th [38][39][40][41][42] and 238 U [45][46][47][48] are given in Tables 6 and 7, respectively. Since there is no data in the mono-energetic neutron-induced fission of 240 Pu, data on the same compound nucleus, i.e., 239 Pu(n, f ) [51], 240 Pu(γ , f ) [75] and 240 Pu(SF) [79], are given in Table 8 for comparison.…”

“…For mono-energetic neutron-induced fission, most of the data available are for actinides induced by either 3 or 14 MeV neutrons [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Some of the data on various mono-energetic neutron-induced fissions of actinides are available for specific nuclides such as 232 Th [38][39][40][41][42], 233,235,238 U [43][44][45][46][47][48], 237 Np [49,50] and 239 Pu [33,51]. Similarly yields of fission fragments in the excitation energy range of the GDR region due to electromagnetic fission in inverse kinematics [52][53][54] are available for neutron-deficient lighter actinides such as 214-223 Ac, 220-229 Th, 224-232 Pa and 231-234 U.…”

Measurement of fission product yields in the quasi-mono-energetic neutron-induced fission of 238U

“…Most of the fission product yields in the 238 U(n, f ) based on off-line and γ -ray spectrometric technique are available within neutron energy of 1. 5-11.3 MeV [24][25][26] and around 14 MeV [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][27][28][29][30][31][32][33]. Some data in the reactor neutron [6,7] and 3.72-10.09 MeV quasi-mono-energetic neutron [35] induced fission of 238 U are also determined by using off-line gamma ray spectrometric technique, where the nuclear structure was clearly shown.…”