  In our previous publications we discussed various manifestations of a new
decay channel of the low excited heavy nuclei called collinear cluster
tri-partition (CCT). The most populated CCT mode was revealed in the mass
correlation distribution of fission fragments (FFs) as a local region ("bump")
of increased yields below the loci linked to the conventional binary fission.
The bump was dubbed "Ni-bump" because it is centered at the masses associated
with the magic isotopes of Ni. Intriguing features of the CCT, especially high
collinearity of the CCT partners and relatively high probability comparable
with that typical for conventional ternary fission, have caused rather wide
discussion. In the majority of dedicated publications, the FFs partitions from
the Ni-bump have been analyzed from the different points of view. In our
publications, we have underlined that Ni-bump manifests itself at the
detectable level only in the spectrometer arm that faces the source backing. So
far, this fact has been left beyond the scope of all known theoretical
considerations, while the backing likely plays a crucial role in the
observation of the CCT experimental pattern.
