Measurements of fission yield in 8 MeV bremsstrahlung induced fission of [sup.232]Th and [sup.238]U

• Published in: Journal of radioanalytical and nuclear chemistry 2014-01, Vol.299 (1), p.127
• Main Authors: Naik, H, Shivashankar, B.S, Prakash, H.G. Raj, Raj, Deves, Sanjeev, Ganesh, Karunakara, N, Somashekarappa, H.M, Ganesan, S, Kim, G.N, Goswami, A
• Format: Article
• Language: English
• Subjects: Comparative analysis; Gamma rays; Measurement; Toy industry; Uranium
• ISSN: 0236-5731
• DOI: 10.1007/s10967-013-2719-0

The cumulative yields (i.e. the sum of isobaric independent yield up to the isobar of interest) for various fission products have been determined in the 8 MeV bremsstrahlung induced fission of [sup.232]Th and [sup.238]U by using off-line gamma ray spectrometric technique. From the cumulative yields of the fission products, their mass-chain yields (i.e. the sum of independent yields of all the isobars) were obtained by using charge distribution correction. The mass-chain yields in the [sup.232]Th(γ, f) and [sup.238]U(γ, f) reactions were compared with the data of similar excitation energy in the [sup.232]Th(n, f) and [sup.238]U(n, f) reactions to examine the effect of nuclear structure. From these data, it was found that the yields of fission products for the mass numbers 133-134, 138-140 and 143-144 as well as their corresponding complementary products are significantly higher than other fission products. Higher yields of the fission products around the mass numbers 133-134 and 143-144 were explained from the standard I and standard II asymmetric mode of fission, which indicates the role of shell closure proximity. However, the amplitude of yields for the mass numbers 133-134 and 143-144 are reverse in the [sup.232]Th(γ, f) and [sup.232]Th(n, f) reactions than in the [sup.238]U(γ, f) and [sup.238]U(n, f) reactions, which has been explained from the point of shell combinations of the complementary fragments. Keywords Nuclear reactions, [sup.232]Th(γ, f) and [sup.238]U(γ, f), [E.sub.γ] = 8 MeV bremsstrahlung, Measured fission product yields and mass-chain yield distribution, Off-line γ-pectroscopy using an HPGe detector, Comparison of fission yield between [sup.232]Th(γ, f) and [sup.238]U(γ, f) reactions