Effects of the N/Z of fissioning systems on the multiplicity of pre-scission particles.

The influences of the neutron-to-proton ratio N/Z of fissioning systems on particle emission for isotopic sources of ^189,202,212Po and for isobaric sources of ²⁰²Tl, ²⁰²Po and ²⁰²Fr are investigated within the framework of Smoluchowski equation. It is shown that the multiplicity of emitted particles shows a strong dependence on the N/Z ratio of the fissioning sources. Calculations also show that when the N/Z ratio of a fissioning system becomes large, charged-particle emission becomes no longer sensitive to viscosity strength, which means that for those systems with larger N/Z ratio, protons and γ-particles are not good probes of extracting the value of the viscosity coefficient in fission. [ABSTRACT FROM AUTHOR]