The experiments of detailed study of No and Rf isotopes radioactive decay properties in complete fusion reactions50Ti+208Pb and48Ca+208,206,204Pb with subsequent neutron evaporation from the excited ...compound nucleus at the kinematic separator SHELS were performed in FLNR JINR. The data of the256Rf decay properties and preliminary data of250No decay properties are presented.
The GRAND universal gas-filled separator, located at the Factory of Super-Heavy Elements in the Flerov Laboratory of Nuclear Reactions (FLNR), Joint Institute for Nuclear Research, has been created ...and put into operation. The separator can be used both in experiments on α, β, and γ spectroscopy of isotopes of heavy and superheavy elements and in experiments on the chemical properties of superheavy elements as a preseparator. The results of the first experimental tests of the GRAND separator are presented. The possibility of effectively carrying out experiments both on a “physical” detection system and on a “chemical” installation has been demonstrated.
In the last years we carried out several experiments aimed to investigate properties of short-lived SF isotopes. The neutron-deficient isotopes of nobelium were produced in fusion-evaporation ...reactions using206,208Pb targets and an intense48Ca-beam. Fusion-evaporation residues were separated by the SHELS separator and implanted into a large-area double-sided (48 × 48) strip silicon detector surrounded by3He-based neutron counters. Half-lives and decay branching ratios for252,254No isotopes were measured. The average number of neutrons per spontaneous fission of254No determined for the first time.
Data is presented on the radioactive decay of isotopes
256
Rf and
249, 250
No synthesized in complete fusion reactions
50
Ti +
208
Pb, and
48
Ca +
204
Pb, with subsequent evaporation of neutrons from ...the excited state of the composite nucleus. Experiments use high-intensity beams of accelerated heavy ions
48
Ca and
50
Ti from the U-400 cyclotron at the Flerov Nuclear Reactions Laboratory of the Joint Institute for Nuclear Research and the SHELS kinematic separator.
Properties of the radioactive decay of No, Rf isotopes are studied in the reaction
50
Ti +
209
Bi →
259
Db* . The cross sections of Db and Rf isotopes production in channels
xn
and
pxn
, ...respectively, are measured. High intensity beams of accelerated heavy ions
22
Ne,
48
Ca,
50
Ti, and
54
Cr of the U400 cyclotron and SHELS kinematic separator are used in the experiments.
.
Recently, we reported the observation of several new isotopes with proton numbers
in low-energy collisions of
48
Ca +
248
Cm . The peculiarity is that the nuclei were produced in multinucleon ...transfer reactions, a method which is presently discussed as a possible new way to enter so far unknown regions in the upper part of the Chart of Nuclides. For separation of the transfer products we used a velocity filter, the Separator for Heavy Ion Reaction Products SHIP at GSI. The resulting strong background suppression allowed us to detect nuclei with cross-sections down to the sub-nanobarn scale. Beside the new isotopes we identified about 100 further target-like transfer products and determined their cross-sections. The results together with previous measurements strongly indicate that multinucleon transfer reactions are a viable pathway to the production of new transuranium isotopes.
Experiments aimed at synthesizing and investigating the features of radioactive decay of isotopes of superheavy elements (
Z
≥ 110) have been conducted in the Flerov Laboratory of Nuclear Reactions ...at the Joint Institute for Nuclear Research. Complete fusion reactions of an accelerated beam of
48
Ca ions with transactinide targets with the subsequent evaporation of several neutrons from excited compound nucleus are typically used in these experiments. “Exotic” reaction channels with the evaporation of protons and several neutrons may be used to produce more neutron-rich isotopes of superheavy elements. The production cross sections were measured in experiments at the SHELS separator for Db and Rf isotopes produced in
xn
and
pxn
channels of the
50
Ti +
209
Bi →
259
Db* reaction. The ratio of cross sections σ(
xn
)/σ(
pxn
) was on the order of 100.
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