A multidimensional neutronic analysis is carried out to determine the extent to which one dimensional neutron transport calculations can be applied to a fusion-fission (hybrid) experimental blanket in cylindrical geometry, driven by a moveable (D,T) target to simulate a 14 MeV neutron line source. Length of the target trajectory has been chosen to be L = 20 and 100 cm by a blanket height of H = 120 cm. The study has shown that, for the proposed blanket, one dimensional calculations will be satisfactory to interpret the experimental neutronic data over a blanket region of Z =1±15 to 25 cm for a trajectory length of L = 120 cm. Whereas these calculations would be applicable over a very narrow strip of the blanket around the Z = 0 plane for a trajectory length of L = 20 cm.