Energy Distribution of the Fragments Resulting from the Fission ofU235andTh232by Slow and by Fast Neutrons

The distribution of energies of the fragments from ${\mathrm{U}}^{235}$ fission produced by slow and by fast neutrons were compared. The energy was determined by using a 10-channel amplitude discriminator to analyze pulses from a Frisch-grid ionization chamber. No difference was found outside the experimental error. The energy distribution of the fragments from thorium fission was also determined. The high energy tails of the distributions were especially investigated for the purpose of detecting the occurrence of triple fission. This indicated a negative result. A possible correlation between the most probable mode of disintegration of the nucleus and its atomic number suggests itself.