EPJ Web of Conferences (Dec 2013)

The investigation of properties of short-lived SF isotopes (Z > 100) at the focal plane of VASSILISSA separator

  • Svirikhin Alexandr,
  • Andreev Alexander,
  • Dushin Victor,
  • Chelnokov Maxim,
  • Chepigin Victor,
  • Gupta Mohini,
  • Isaev Andrey,
  • Izosimov Igor,
  • Katrasev Denis,
  • Kuznetsov Alexey,
  • Malyshev Oleg,
  • Minkova Ani,
  • Mullins Simon,
  • Popeko Andrey,
  • Sokol Evgeniy,
  • Yeremin Alexander

DOI
https://doi.org/10.1051/epjconf/20136203005
Journal volume & issue
Vol. 62
p. 03005

Abstract

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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. The reaction 48Ca + 206Pb = 2n + 252No is used for tuning the separator settings and calibrating the detector system with the spontaneous fission of the 252No. The average neutron number per 252No spontaneous fission event is as large as ν̅ = 4.06 ± 0.12. The short-lived heavy isotopes 244,246Fm, produced in the complete fusion reactions 40Ar + 206,208Pb, are investigated. The average number of neutrons per spontaneous fission of 244,246Fm from the experimental data were (ν̅ = 3.3 ± 0.3) and (ν̅ = 3.55 ± 0.50), respectively. Both values are determined for the first time.