The results of a careful investigation of the mass-energy-charge corre
lations of the fragments produced by fission of thorium-232 by 5 MeV n
eutrons are presented. The phenomenon of truly cold fragmentation of a
thorium nucleus into tellurium-134 and strontium-99 in the quantum gr
ound states is observed. It is shown that the reaction energy is compl
etely exhausted by the kinetic energy of the fragments in their mutual
field. (C) 1998 American Institute of Physics. [S0021-3640(98)00710-5
].