Isotopes of tennessine

Tennessine (₁₁₇Ts) is the most-recently synthesized synthetic element, and much of the data is hypothetical. As for any synthetic element, a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first (and so far only) isotopes to be synthesized were ²⁹³Ts and ²⁹⁴Ts in 2009. The longer-lived isotope is ²⁹⁴Ts with a half-life of 51 ms.

List of isotopes

Nuclide	Z	N	Isotopic mass (Da)^[4] ^{[n 1]}^{[n 2]}	Half-life^[1]	Decay mode^[1]	Daughter isotope
²⁹³Ts	117	176	293.20873(84)#	22+8 −4 ms [25(6) ms]	α	²⁸⁹Mc
²⁹⁴Ts	117	177	294.21084(64)#	51+38 −16 ms [70(30) ms]	α	²⁹⁰Mc
This table header & footer: view

^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

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 JINR (Flerov Laboratory of Nuclear Reactions) ran a 7-month-long experiment to synthesize tennessine using the reaction above.^[5] The expected cross-section was of the order of 2 pb. The expected evaporation residues, ²⁹³Ts and ²⁹⁴Ts, were predicted to decay via relatively long decay chains as far as isotopes of dubnium or lawrencium.

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)	σ_max	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

^ ^a ^b ^c ^d ^e Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
^ Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch. E.; et al. (2014). "⁴⁸Ca+²⁴⁹Bk Fusion Reaction Leading to Element Z=117: Long-Lived α-Decaying ²⁷⁰Db and Discovery of ²⁶⁶Lr". Physical Review Letters. 112 (17): 172501. Bibcode:2014PhRvL.112q2501K. doi:10.1103/PhysRevLett.112.172501. PMID 24836239.
^ Oganessian, Yu. Ts.; et al. (2013). "Experimental studies of the ²⁴⁹Bk + ⁴⁸Ca reaction including decay properties and excitation function for isotopes of element 117, and discovery of the new isotope ²⁷⁷Mt". Physical Review C. 87 (5): 054621. Bibcode:2013PhRvC..87e4621O. doi:10.1103/PhysRevC.87.054621.
^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
^ 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
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Zhao-Qing, Feng; Gen-Ming, Jin; Ming-Hui, Huang; Zai-Guo, Gan; Nan, Wang; Jun-Qing, Li (2007). "Possible Way to Synthesize Superheavy Element Z = 117". Chinese Physics Letters. 24 (9): 2551. arXiv:0708.0159. Bibcode:2007ChPhL..24.2551F. doi:10.1088/0256-307X/24/9/024. S2CID 250860387.
^ ^a ^b Feng, Z; Jin, G; Li, J; Scheid, W (2009). "Production of heavy and superheavy nuclei in massive fusion reactions". Nuclear Physics A. 816 (1–4): 33. arXiv:0803.1117. Bibcode:2009NuPhA.816...33F. doi:10.1016/j.nuclphysa.2008.11.003. S2CID 18647291.
^ C. Samanta; P. Roy Chowdhury; D. N. Basu (2007). "Predictions of alpha decay half lives of heavy and superheavy elements". Nuclear Physics A. 789 (1–4): 142–154. arXiv:nucl-th/0703086. Bibcode:2007NuPhA.789..142S. doi:10.1016/j.nuclphysa.2007.04.001. S2CID 7496348.
^ P. Roy Chowdhury; C. Samanta; D. N. Basu (2008). "Search for long lived heaviest nuclei beyond the valley of stability". Physical Review C. 77 (4): 044603. arXiv:0802.3837. Bibcode:2008PhRvC..77d4603C. doi:10.1103/PhysRevC.77.044603. S2CID 119207807.
^ P. Roy Chowdhury; C. Samanta; D. N. Basu (2008). "Nuclear half-lives for α -radioactivity of elements with 100 ≤ Z ≤ 130". Atomic Data and Nuclear Data Tables. 94 (6): 781–806. arXiv:0802.4161. Bibcode:2008ADNDT..94..781C. doi:10.1016/j.adt.2008.01.003. S2CID 96718440.

[5] ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[TMS-6] # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[NUBASE2020-1] Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

[266Lr-2] Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch. E.; et al. (2014). "⁴⁸Ca+²⁴⁹Bk Fusion Reaction Leading to Element Z=117: Long-Lived α-Decaying ²⁷⁰Db and Discovery of ²⁶⁶Lr". Physical Review Letters. 112 (17): 172501. Bibcode:2014PhRvL.112q2501K. doi:10.1103/PhysRevLett.112.172501. PMID 24836239.

[277Mt-3] Oganessian, Yu. Ts.; et al. (2013). "Experimental studies of the ²⁴⁹Bk + ⁴⁸Ca reaction including decay properties and excitation function for isotopes of element 117, and discovery of the new isotope ²⁷⁷Mt". Physical Review C. 87 (5): 054621. Bibcode:2013PhRvC..87e4621O. doi:10.1103/PhysRevC.87.054621.

[AME2020_II-4] Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.

[7] Tennessine – the 117th element at AtomInfo.ru

[saigadak-8] 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.

[E117-9] Recommendations: 31st meeting, PAC for Nuclear Physics Archived 2010-04-14 at the Wayback Machine

[10] Walter Grenier: Recommendations, a PowerPoint presentation at the January 2010 meeting of the PAC for Nuclear Physics

[FengE117-11] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Zhao-Qing, Feng; Gen-Ming, Jin; Ming-Hui, Huang; Zai-Guo, Gan; Nan, Wang; Jun-Qing, Li (2007). "Possible Way to Synthesize Superheavy Element Z = 117". Chinese Physics Letters. 24 (9): 2551. arXiv:0708.0159. Bibcode:2007ChPhL..24.2551F. doi:10.1088/0256-307X/24/9/024. S2CID 250860387.

[FengHotFusion-12] Feng, Z; Jin, G; Li, J; Scheid, W (2009). "Production of heavy and superheavy nuclei in massive fusion reactions". Nuclear Physics A. 816 (1–4): 33. arXiv:0803.1117. Bibcode:2009NuPhA.816...33F. doi:10.1016/j.nuclphysa.2008.11.003. S2CID 18647291.

[prediction117-13] C. Samanta; P. Roy Chowdhury; D. N. Basu (2007). "Predictions of alpha decay half lives of heavy and superheavy elements". Nuclear Physics A. 789 (1–4): 142–154. arXiv:nucl-th/0703086. Bibcode:2007NuPhA.789..142S. doi:10.1016/j.nuclphysa.2007.04.001. S2CID 7496348.

[14] P. Roy Chowdhury; C. Samanta; D. N. Basu (2008). "Search for long lived heaviest nuclei beyond the valley of stability". Physical Review C. 77 (4): 044603. arXiv:0802.3837. Bibcode:2008PhRvC..77d4603C. doi:10.1103/PhysRevC.77.044603. S2CID 119207807.

[15] P. Roy Chowdhury; C. Samanta; D. N. Basu (2008). "Nuclear half-lives for α -radioactivity of elements with 100 ≤ Z ≤ 130". Atomic Data and Nuclear Data Tables. 94 (6): 781–806. arXiv:0802.4161. Bibcode:2008ADNDT..94..781C. doi:10.1016/j.adt.2008.01.003. S2CID 96718440.

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