Eur. Phys. J. A (2010) 44: 393-396
https://doi.org/10.1140/epja/i2010-10968-0

Regular Article - Experimental Physics

Neutron multiplicity at spontaneous fission of ²⁴⁶Fm

¹ Flerov Laboratory of Nuclear Reactions, JINR, 141980, Dubna, Russia
² V.G. Khlopin Radium Institute, 194021, St. Petersburg, Russia
³ Institute for Nuclear Research and Nuclear Energy, 1784, Sofia, Bulgaria

^* e-mail: asvirikhin@jinr.ru

Received: 26 February 2010
Revised: 17 March 2010
Accepted: 4 April 2010
Published online: 7 May 2010

Abstract

The neutron-deficient isotope ²⁴⁶Fm , produced in the complete fusion reaction

⁴⁰Ar$ + $²⁰⁸Pb

, was investigated. The main goal of the experiment was to determine the neutron multiplicity at spontaneous fission of this isotope. For experiments aimed at the study of spontaneous fission of transfermium nuclei improvements in the focal plane detector system of recoil separator VASSILISSA have been made. A neutron detector consisting of 54 ³He -filled counters has been mounted around the focal-plane detector chamber. From the experimental data the average number of neutrons per spontaneous fission of ²⁴⁶Fm was determined ( = 3.55±0.5) .