Isotopes of tennessine
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List of isotopes
Nuclide |
Z | N | Isotopic mass (Da)[4] [n 1][n 2] |
Half-life |
Decay mode |
Daughter isotope |
Spin and parity | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
293Ts | 117 | 176 | 293.20873(84)# | 22+8 −4 ms[3] |
α | 289Mc | |||||||||||||
294Ts | 117 | 177 | 294.21084(64)# | 51+41 −16 ms[2] |
α | 290Mc | |||||||||||||
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Isotopes and nuclear properties
Nucleosynthesis
Target-projectile combinations leading to Z=117 compound nuclei
The below table contains various combinations of targets and projectiles that could be used to form compound nuclei with atomic number 117.
Target | Projectile | CN | Attempt result |
---|---|---|---|
208Pb | 81Br | 289Ts | Yet to be attempted |
209Bi | 82Se | 291Ts | Yet to be attempted |
238U | 55Mn | 293Ts | Yet to be attempted |
243Am | 50Ti | 293Ts | Yet to be attempted |
249Bk | 48Ca | 297Ts | Successful reaction |
Hot fusion
249Bk(48Ca,xn)297−xTs (x=3,4)
Between July 2009 and February 2010, the team at the
-
Calculated decay chains from the parent nuclei 293Ts and 294Ts[6]
The team published a paper in April 2010 (first results were presented in January 2010[7]) that six atoms of the isotopes 294Ts (one atom) and 293Ts (five atoms) were detected. 294Ts decayed by six alpha decays down as far as the new isotope 270Db, which underwent apparent spontaneous fission. The lighter odd-even isotope underwent just three alpha decays, as far as 281Rg, which underwent spontaneous fission. The reaction was run at two different excitation energies, 35 MeV (dose 2×1019) and 39 MeV (dose 2.4×1019). Initial decay data was published as a preliminary presentation on the JINR website.[8]
A further experiment in May 2010, aimed at studying the chemistry of the granddaughter of tennessine, nihonium, identified a further two atoms of 286Nh from decay of 294Ts. The original experiment was repeated successfully by the same collaboration in 2012 and by a joint German–American team in May 2014, confirming the discovery.
Chronology of isotope discovery
Isotope | Year discovered | Reaction |
---|---|---|
294Ts | 2009 | 249Bk(48Ca,3n) |
293Ts | 2009 | 249Bk(48Ca,4n) |
Theoretical calculations
Evaporation residue cross sections
The below table contains various targets-projectile combinations for which calculations have provided estimates for cross section yields from various neutron evaporation channels. The channel with the highest expected yield is given.
DNS = Di-nuclear system; σ = cross section
Target | Projectile | CN | Channel (product) | σmax | Model | Ref |
---|---|---|---|---|---|---|
209Bi | 82Se | 291Ts | 1n (290Ts) | 15 fb | DNS | [9] |
209Bi | 79Se | 288Ts | 1n (287Ts) | 0.2 pb | DNS | [9] |
232Th | 59Co | 291Ts | 2n (289Ts) | 0.1 pb | DNS | [9] |
238U | 55Mn | 293Ts | 2-3n (291,290Ts) | 70 fb | DNS | [9] |
244Pu | 51V | 295Ts | 3n (292Ts) | 0.6 pb | DNS | [9] |
248Cm | 45Sc | 293Ts | 4n (289Ts) | 2.9 pb | DNS | [9] |
246Cm | 45Sc | 291Ts | 4n (287Ts) | 1 pb | DNS | [9] |
249Bk | 48Ca | 297Ts | 3n (294Ts) | 2.1 pb ; 3 pb | DNS | [9][10] |
247Bk | 48Ca | 295Ts | 3n (292Ts) | 0.8, 0.9 pb | DNS | [9][10] |
Decay characteristics
Theoretical calculations in a quantum tunneling model with mass estimates from a macroscopic-microscopic model predict the alpha-decay half-lives of isotopes of tennessine (namely, 289–303Ts) to be around 0.1–40 ms.[11][12][13]
References
- ^ .
- ^ PMID 24836239.
- ^ .
- .
- ^ Tennessine – the 117th element at AtomInfo.ru
- ^ Roman Sagaidak. "Experiment setting on synthesis of superheavy nuclei in fusion-evaporation reactions. Preparation to synthesis of new element with Z=117" (PDF). Archived from the original (PDF) on 2011-07-03. Retrieved 2009-07-07.
- ^ Recommendations: 31st meeting, PAC for Nuclear Physics Archived 2010-04-14 at the Wayback Machine
- ^ Walter Grenier: Recommendations, a PowerPoint presentation at the January 2010 meeting of the PAC for Nuclear Physics
- ^ S2CID 250860387.
- ^ S2CID 18647291.
- S2CID 7496348.
- S2CID 119207807.
- S2CID 96718440.