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Zhang ZY, Gan ZG, Yang HB, Ma L, Huang MH, Yang CL, Zhang MM, Tian YL, Wang YS, Sun MD, Lu HY, Zhang WQ, Zhou HB, Wang X, Wu CG, Duan LM, Huang WX, Liu Z, Ren ZZ, Zhou SG, Zhou XH, Xu HS, Tsyganov YS, Voinov AA, Polyakov AN. New Isotope ^{220}Np: Probing the Robustness of the N=126 Shell Closure in Neptunium. Phys Rev Lett 2019; 122:192503. [PMID: 31144958 DOI: 10.1103/physrevlett.122.192503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/10/2019] [Indexed: 06/09/2023]
Abstract
A new short-lived neutron-deficient isotope ^{220}Np was synthesized in the fusion-evaporation reaction ^{185}Re(^{40}Ar,5n)^{220}Np at the gas-filled recoil separator SHANS. Based on the measurement of the correlated α-decay chains, the decay properties of ^{220}Np with E_{α}=10040(18) keV and T_{1/2}=25_{-7}^{+14} μs were determined, which are in good agreement with theoretical predictions. From the new experimental results coupled with the recently reported α-decay data of ^{219,223}Np, the α-decay systematics for Np isotopes around N=126 was established, which allows us for the first time to test the robustness of the N=126 shell closure in Z=93 Np isotopes. The results also indicate that, in the region of nuclei with Z≥83, the proton drip line has been reached for all odd-Z isotopes up to Np.
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Affiliation(s)
- Z Y Zhang
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Z G Gan
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - H B Yang
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - L Ma
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - M H Huang
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - C L Yang
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - M M Zhang
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Y L Tian
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Y S Wang
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - M D Sun
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - H Y Lu
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - W Q Zhang
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - H B Zhou
- Guangxi Key Laboratory of Nuclear Physics and Technology, Guangxi Normal University, Guilin 541004, China
| | - X Wang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - C G Wu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - L M Duan
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - W X Huang
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Z Liu
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Z Z Ren
- School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - S G Zhou
- CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
- Center of Theoretical Nuclear Physics, National Laboratory of Heavy-Ion Accelerator, Lanzhou 730000, China
| | - X H Zhou
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - H S Xu
- CAS Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu S Tsyganov
- Joint Institute for Nuclear Research, RU-141980 Dubna, Russian Federation
| | - A A Voinov
- Joint Institute for Nuclear Research, RU-141980 Dubna, Russian Federation
| | - A N Polyakov
- Joint Institute for Nuclear Research, RU-141980 Dubna, Russian Federation
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Oganessian YT, Abdullin FS, Alexander C, Binder J, Boll RA, Dmitriev SN, Ezold J, Felker K, Gostic JM, Grzywacz RK, Hamilton JH, Henderson RA, Itkis MG, Miernik K, Miller D, Moody KJ, Polyakov AN, Ramayya AV, Roberto JB, Ryabinin MA, Rykaczewski KP, Sagaidak RN, Shaughnessy DA, Shirokovsky IV, Shumeiko MV, Stoyer MA, Stoyer NJ, Subbotin VG, Sukhov AM, Tsyganov YS, Utyonkov VK, Voinov AA, Vostokin GK. Production and decay of the heaviest nuclei (293,294)117 and (294)118. Phys Rev Lett 2012; 109:162501. [PMID: 23215070 DOI: 10.1103/physrevlett.109.162501] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Indexed: 06/01/2023]
Abstract
Two years after the discovery of element 117, we undertook a second campaign using the (249)Bk+(48)Ca reaction for further investigations of the production and decay properties of the isotopes of element 117 on a larger number of events. The experiments were started in the end of April 2012 and are still under way. This Letter presents the results obtained in 1200 hours of an experimental run with the beam dose of (48)Ca of about 1.5×10(19) particles. The (249)Bk target was irradiated at two energies of (48)Ca that correspond to the maximum probability of the reaction channels with evaporation of three and four neutrons from the excited (297)117. In this experiment, two decay chains of (294)117 (3n) and five decay chains of (293)117 (4n) were detected. In the course of the long-term work, (249)Cf-the product of decay of (249)Bk (330 d)-is being accumulated in the target. Consequently, in the present experiment, we also detected a single decay of the known isotope (294)118 that was produced during 2002-2005 in the reaction (249)Cf((48)Ca,3n)(294)118. The obtained results are compared with the data from previous experiments. The experiments are carried out in the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, using the heavy-ion cyclotron U400.
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Affiliation(s)
- Yu Ts Oganessian
- Joint Institute for Nuclear Research, RU-141980 Dubna, Russian Federation.
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Oganessian YT, Abdullin FS, Dmitriev SN, Gostic JM, Hamilton JH, Henderson RA, Itkis MG, Moody KJ, Polyakov AN, Ramayya AV, Roberto JB, Rykaczewski KP, Sagaidak RN, Shaughnessy DA, Shirokovsky IV, Stoyer MA, Subbotin VG, Sukhov AM, Tsyganov YS, Utyonkov VK, Voinov AA, Vostokin GK. New insights into the 243Am + 48Ca reaction products previously observed in the experiments on elements 113, 115, and 117. Phys Rev Lett 2012; 108:022502. [PMID: 22324675 DOI: 10.1103/physrevlett.108.022502] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Indexed: 05/31/2023]
Abstract
Results of a new series of experiments on the study of production cross sections and decay properties of the isotopes of element 115 in the reaction (243)Am+(48)Ca are presented. Twenty-one new decay chains originating from (288)115 were established as the product of the 3n-evaporation channel by measuring the excitation function at three excitation energies of the compound nucleus (291)115. The decay properties of all newly observed nuclei are in full agreement with those we measured in 2003. At the lowest excitation energy E*=33 MeV, for the first time we registered the product of the 2n-evaporation channel, (289)115, which was also observed previously in the reaction (249)Bk+(48)Ca as the daughter nucleus of the decay of (293)117. The maximum cross section for the production of (288)115 is found to be 8.5 pb at E*≈36 MeV.
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Affiliation(s)
- Yu Ts Oganessian
- Joint Institute for Nuclear Research, Dubna, Russian Federation.
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Oganessian YT, Abdullin FS, Bailey PD, Benker DE, Bennett ME, Dmitriev SN, Ezold JG, Hamilton JH, Henderson RA, Itkis MG, Lobanov YV, Mezentsev AN, Moody KJ, Nelson SL, Polyakov AN, Porter CE, Ramayya AV, Riley FD, Roberto JB, Ryabinin MA, Rykaczewski KP, Sagaidak RN, Shaughnessy DA, Shirokovsky IV, Stoyer MA, Subbotin VG, Sudowe R, Sukhov AM, Tsyganov YS, Utyonkov VK, Voinov AA, Vostokin GK, Wilk PA. Synthesis of a new element with atomic number Z = 117. Phys Rev Lett 2010; 104:142502. [PMID: 20481935 DOI: 10.1103/physrevlett.104.142502] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Indexed: 05/29/2023]
Abstract
The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes (293)117 and (294)117 were produced in fusion reactions between (48)Ca and (249)Bk. Decay chains involving 11 new nuclei were identified by means of the Dubna gas-filled recoil separator. The measured decay properties show a strong rise of stability for heavier isotopes with Z > or = 111, validating the concept of the long sought island of enhanced stability for superheavy nuclei.
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Affiliation(s)
- Yu Ts Oganessian
- Joint Institute for Nuclear Research, RU-141980 Dubna, Russian Federation.
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