New results on the synthesis of element 115 in the reaction 243 Am+ 48 Ca V.K. Utyonkov Objective: additional identification of odd Z=113, 115 and 117 nuclei Radioactive properties of even-Z nuclei In accordance with the criteria for the discovery of elements previously established by the 1992 IUPAC/IUPAP Transfermium Working Group (TWG), and reinforced in subsequent IUPAC/IUPAP JWP discussions, it was determined that the Dubna-Livermore collaborations share in the fulfillment of those criteria both for elements Z = 114 and 116 .
Transcript
New results on the synthesis of element 115 in the reaction 243Am+48Ca
V.K. Utyonkov
Objective: additional identification of odd Z=113, 115 and 117 nuclei
Radioactive properties of even-Z nuclei
In accordance with the criteria for the discovery of elements previously established by the 1992 IUPAC/IUPAP Transfermium Working Group (TWG), and reinforced in subsequent IUPAC/IUPAP JWP discussions, it was determined that the Dubna-Livermore collaborations share in the fulfillment of those criteria both for elements Z = 114 and 116.
Production properties of even-Z nuclei: yield curve
Cross bombardments
chemical identification:group 5 element 268Db
Cross bombardments
1. More decay chains2. Excitation function3. Cross bombardments
Gas-Filled Recoil Separator
r = 1.8 mB r max = 3.1 Tm
max gradient = 13 T/m
Target thickness mg/cm2
E lab (MeV) E exc (MeV) Beam dosex 1018
Number of chains
0.37 248 38.0-42.3 3.7 3
0.37 243 34.0-38.3 3.3 6
0.37 240 31.1-35.3 11.7 7
0.84 241 31.4-36.2 4.8 5+1
Radioactive properties of odd-Z nuclei
Radioactive properties of odd-Z nuclei
Production properties of odd-Z nuclei: yield curve
Radioactive properties of odd-Z nuclei
266-270DbSF/b
Future experiments: excitation function identification of Z by X-rays of 268Rf
Summary:
Discovery of elements 113 and 115 produced in 2003 was confirmed byobservation of 21 new decay chains originating from 288115, the product of the 3n-evaporation channel of the reaction 243Am+48Ca.Decay properties of all the six nuclei 288115, 284113, 280Rg, 276Mt, 272Bh, and 268Db synthesized in 2003 are in full agreement with those measured in the recent experiments.
Excitation function of the reaction 243Am+48Ca was measured at three lower projectile energies. Experiments are to be continued.
Discovery of element 117 was confirmed by registration of the decay chain of 289115 which was produced for the first time in the reaction 249Bk(48Ca,4n) as the descendant nucleus of 293117. The isotope 289115 was synthesized in two cross bombardments.
R.N. Sagaidak,1 D.A. Shaughnessy,5 I.V. Shirokovsky,1 M.A. Stoyer,5 V.G. Subbotin,1 R. Sudowe,3 A.M. Sukhov,1 R. Taylor,2 Yu.S. Tsyganov,1 V.K. Utyonkov,1 A.A. Voinov,1 G.K. Vostokin,1 and P.A. Wilk5
1Joint Institute for Nuclear Research, RU-141980 Dubna, Russian Federation2Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA3University of Nevada Las Vegas, Las Vegas, Nevada 89154, USA4Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA5Lawrence Livermore National Laboratory, Livermore, California 94551, USA6Research Institute of Atomic Reactors, RU-433510 Dimitrovgrad, Russian Federation
