Collinear Tripartition Of Cm-248 And Cf-252 Nuclei As A Probe Of Clustering

Among the events due to the spontaneous decay of the Cm-248 and Cf-252 nuclei some events with an yield similar to 10(-5) / 10(-6) have been detected for which the total mass of two complimentary fragments is about 30% smaller than the mass of the fissioning nuclei. The mass-energy correlations for the rare events allow one to associate: them with the fission of the system via very elongated and highly deformed three-cluster chain-like configurations. This process observed for the first time on reasonably be treated as a collinear cluster tripartition of a heavy nucleus.