Eur. Phys. J. A (2012) 48: 94
https://doi.org/10.1140/epja/i2012-12094-5

Regular Article - Experimental Physics

The collinear cluster tri-partition (CCT) of ²⁵²Cf (sf): New aspects from neutron gated data

¹ Joint Institute for Nuclear Research, 141980, Dubna, 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, 119899, Moscow, Russia
⁵ Faculty of Military Science, University of Stellenbosch, 7395, Saldanha, South Africa
⁶ Institute for Nuclear Research RAN, 117312, Moscow, Russia

Received: 19 December 2011
Accepted: 28 June 2012
Published online: 19 July 2012

Abstract

Results of two different experiments for the study of fission of ²⁵²Cf (sf) events in coincidence with neutrons are reported. Two time-of-flight-energy (TOF-E detectors systems have been used. The fission fragment masses were obtained in a double arm coincidence set-up, where the missing mass in the binary decay is used to characterise ternary fission as a collinear cluster tri-partition (CCT). The ³He filled neutron counters have been arranged so as to detect principally neutrons emitted from an isotropic source in the laboratory frame. The fission events connected to the larger experimental neutron multiplicities show a wide range in the missing-mass spectrum, down to -particles, carbon and oxygen isotopes. These are linked with magic nuclei in the binary mass-mass correlations of the fission fragments. These neutron gated data are virtually free from background events from scattered binary fission fragments. The ungated spectra are compared to those of the previous data from our previous article (Eur. Phys. J. A. 45, 29 (2010)), the observed structures agree well with the manifestations of the collinear cluster tri-partition of ²⁵²Cf (sf) observed earlier. Several new families of the CCT modes are observed.