MASS AND ENERGY-DEPENDENCE OF PION-INDUCED FISSION

Data for fission induced by pi meson beams from 80 to 500 MeV are pres ented for nuclei from Fe through Pu as measured by solid state track d etectors. The general trends for binary fission with pi(+) are reprodu ced fairly well by a calculation in the 'high excitation' limit with s tandard level density and fission barrier parameters, but pi(-) data a re underpredicted. A universal dependence of the binary fission probab ilities with the fissility (Z +/- 1)(2)/A is found to be valid for bot h pion beam charges for all beam energies below the delta resonance. P robabilities for observing three fragments with pi(+) are not reproduc ed by a ternary fission application of the model found to work for bin ary fission.