Eur. Phys. J. A (2010) 45: 29-37
https://doi.org/10.1140/epja/i2010-10988-8

Regular Article - Experimental Physics

Collinear cluster tri-partition of ²⁵²Cf (sf) and in the ²³⁵U (n_th, f ) reaction

¹ Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia
² National Nuclear Research University MEPHI, 115409, Moscow, Russia
³ Helmholtz-Zentrum Berlin, Glienickerstr. 100, 14109, Berlin, Germany
⁴ Physics Faculty, Computer Methods in Physics Division, Lomonosov Moscow State University, Moscow, 119899, Russia
⁵ Department of Physics, University of Jyväskylä, Jyväskylä, Finland

Received: 8 February 2010
Revised: 10 May 2010
Accepted: 12 May 2010
Published online: 9 June 2010

Abstract

Experimental results in favour of the existence of a new type of cluster decay called “collinear cluster tri-partition”, CCT, are presented. They are based on two different experiments with binary coincidences and measurements of the masses and energies of the two fragments, as well as using in one of the experiments observables sensitive to the nuclear charge of the fission fragments. A relatively high yield of the CCT-effect (more than 10^-3per binary fission) is likely due to the favourable Q -values (more positive than binary) and is expected due to a collective motion through very elongated (hyper-deformed) pre-scission shapes of the mother system. The process is considered to result from a sequential process, where a heavy cluster (lead as in the case of known cluster radioactivity) is replaced by pairs of two lighter clusters such as the magic isotopes of Sn/Ni or Sn/Ge.