Fission fragment anisotropies for ~(19)F + ~(209)Bi system

摘要

The fission fragment angular distributions have been measured for the system ~(19)F + ~(209)Bi over a range of bombarding energies from 88.0 MeV to 125.6 MeV. The measured fission fragment anisotropies are in agreement with the saddle point statistical model calculations in the above energy range. Combining these data with those available for ~(11)B, ~(12)C, ~(14)N, ~(16)O and ~(18)O + ~(209)Bi, ~(208)Pb systems, it is concluded that the spherical target plus projectile systems behave 'normal' from near- to above - barrier energies. This observation is in contrast to the 'anomalous' anisotropies exhibited by the deformed actinide target - projectile systems at near - barrier energies.