The ratio of asymmetric to symmetric fission in fission of 239Pu by neutrons of energies from 30 keV to 14.7 MeV

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

“…In the electromagnetic fission of lighter actinides [52][53][54], higher yields of fission products around mass numbers 133-135 corresponding to a most probable charge of 52 have been observed. Similarly, higher yields of fission products around mass numbers 133-135 in the 3 and 14 MeV mono-energetic neutron-induced [28][29][30][31][32][33][34] and in the 9, 15 and 31 MeV bremsstrahlunginduced [59] fission of 232 Th have also been observed earlier. However, in the 6.44-13.13 MeV bremsstrahlung-induced fission of 232 Th [60], yields of fission products are more pronounced around mass numbers 143-145 compared to mass numbers 133-135, which is contradictory to the earlier observations [23][24][25][26][27]59].…”

“…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.…”

“…However, most of the fission yield data available in the literature are for the thermal neutron- [10][11][12][13] or reactor neutron-induced [14][15][16][17][18][19][20][21][22] fission of actinides. 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].…”

“…However, the yield of fission products around mass numbers 133-135 is more pronounced compared to mass numbers 143-145, in both neutron- [28][29][30][31][32][33] and bremsstrahlung-induced [61][62][63][64][65][66][67][68][69][70][71][72][73][74] fission of uranium isotopes and heavier actinides. In the electromagnetic fission of lighter actinides [52][53][54], higher yields of fission products around mass numbers 133-135 corresponding to a most probable charge of 52 have been observed.…”

“…These data, along with similar data in the bremsstrahlung-and neutron-induced fission of 232 Th, 238 U and 240 Pu over a wide range of energy are interpreted from the point of view of nuclear structure effects and excitation energy transfer. For the compound nucleus 240 Pu * , the experimental data in the bremsstrahlung-induced fission of 240 Pu were compared with similar data of thermal [11][12][13] and mono-energetic neutron-induced [33,51] fission of 239 Pu and spontaneous fission of 240 Pu [75,79]. This comparison can provide information about different fission mechanisms of the bremsstrahlung-and mono-energetic neutron-induced fission of actinides due to incomplete/non-compound energy mixing in the former case.…”