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Isotopes of tennessine

From Wikipedia, the free encyclopedia

Isotopes oftennessine (117Ts)
Main isotopes[1]Decay
Isotopeabun­dancehalf-life(t1/2)modepro­duct
293Tssynth22 ms[1][2]α289Mc
294Tssynth51 ms[3]α290Mc

Tennessine (117Ts) is the most-recently synthesizedsynthetic element, and much of the data is hypothetical. As for any synthetic element, astandard atomic weight cannot be given. Like all synthetic elements, it has nostable isotopes. The first (and so far only)isotopes to be synthesized were293Ts and294Ts in 2009. The longer-lived isotope is294Ts with ahalf-life of 51 ms.

List of isotopes

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Nuclide
ZNIsotopic mass(Da)[4]
[n 1][n 2]		Half-life[1]
Decay
mode[1]
Daughter
isotope
Spin and
parity[1]
293Ts117176293.20873(84)#22+8
−4 ms
[25(6) ms]		α289Mc
294Ts117177294.21084(64)#51+38
−16 ms
[70(30) ms]		α290Mc
This table header & footer:
  1. ^( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  2. ^# – 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

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Nucleosynthesis

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Target-projectile combinations leading to Z=117 compound nuclei

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The below table contains various combinations of targets and projectiles that could be used to form compound nuclei with atomic number 117.

TargetProjectileCNAttempt result
208Pb81Br289TsYet to be attempted
209Bi82Se291TsYet to be attempted
238U55Mn293TsYet to be attempted
243Am50Ti293TsYet to be attempted
249Bk48Ca297TsSuccessful reaction

Hot fusion

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249Bk(48Ca,xn)297−xTs (x=3,4)
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Between July 2009 and February 2010, the team at theJINR (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 2pb. The expected evaporation residues,293Ts and294Ts, were predicted to decay via relatively long decay chains as far as isotopes ofdubnium orlawrencium.

  • Calculated decay chains from the parent nuclei 293Ts and 294Ts[6]
    Calculated decay chains from the parent nuclei293Ts and294Ts[6]


The team published a paper in April 2010 (first results were presented in January 2010[7]) that six atoms of the isotopes294Ts (one atom) and293Ts (five atoms) were detected.294Ts decayed by sixalpha decays down as far as the new isotope270Db, which underwent apparent spontaneous fission. The lighter odd-even isotope underwent just three alpha decays, as far as281Rg, 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 of286Nh from decay of294Ts. 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

[edit]
IsotopeYear discoveredReaction
294Ts2009249Bk(48Ca,3n)
293Ts2009249Bk(48Ca,4n)

Theoretical calculations

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Evaporation residue cross sections

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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

TargetProjectileCNChannel (product)σmaxModelRef
209Bi82Se291Ts1n (290Ts)15 fbDNS[9]
209Bi79Se288Ts1n (287Ts)0.2 pbDNS[9]
232Th59Co291Ts2n (289Ts)0.1 pbDNS[9]
238U55Mn293Ts2-3n (291,290Ts)70 fbDNS[9]
244Pu51V295Ts3n (292Ts)0.6 pbDNS[9]
248Cm45Sc293Ts4n (289Ts)2.9 pbDNS[9]
246Cm45Sc291Ts4n (287Ts)1 pbDNS[9]
249Bk48Ca297Ts3n (294Ts)2.1 pb ; 3 pbDNS[9][10]
247Bk48Ca295Ts3n (292Ts)0.8, 0.9 pbDNS[9][10]

Decay characteristics

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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

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  1. ^abcdeKondev, 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.
  2. ^Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch. E.; et al. (2014)."48Ca+249Bk Fusion Reaction Leading to Element Z=117: Long-Lived α-Decaying270Db and Discovery of266Lr".Physical Review Letters.112 (17) 172501.Bibcode:2014PhRvL.112q2501K.doi:10.1103/PhysRevLett.112.172501.PMID 24836239.
  3. ^Oganessian, Yu. Ts.; et al. (2013). "Experimental studies of the249Bk +48Ca reaction including decay properties and excitation function for isotopes of element 117, and discovery of the new isotope277Mt".Physical Review C.87 (5) 054621.Bibcode:2013PhRvC..87e4621O.doi:10.1103/PhysRevC.87.054621.
  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.
  5. ^Tennessine – the 117th element at AtomInfo.ru
  6. ^Roman Sagaidak."Experiment setting on synthesis of superheavy nuclei in fusion-evaporation reactions. Preparation to synthesis of new element with Z=117"(PDF). Archived fromthe original(PDF) on 2011-07-03. Retrieved2009-07-07.
  7. ^Recommendations: 31st meeting, PAC for Nuclear PhysicsArchived 2010-04-14 at theWayback Machine
  8. ^Walter Grenier: Recommendations, a PowerPoint presentation at the January 2010 meeting of the PAC for Nuclear Physics
  9. ^abcdefghiZhao-Qing, Feng; Gen-Ming, Jin; Ming-Hui, Huang; Zai-Guo, Gan; Nan, Wang; Jun-Qing, Li (2007). "Possible Way to Synthesize Superheavy ElementZ = 117".Chinese Physics Letters.24 (9): 2551.arXiv:0708.0159.Bibcode:2007ChPhL..24.2551F.doi:10.1088/0256-307X/24/9/024.S2CID 250860387.
  10. ^abFeng, 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.
  11. ^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.
  12. ^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.
  13. ^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.
Group12 3456789101112131415161718
PeriodHydrogen and
alkali metals		Alkaline
earth metals		Pnicto­gensChal­co­gensHalo­gensNoble gases
①12
②345678910
③1112131415161718
④192021222324252627282930313233343536
⑤373839404142434445464748495051525354
⑥55561 asterisk71727374757677787980818283848586
⑦87881 asterisk103104105106107108109110111112113114115116117118
⑧119120
1 asterisk5758596061626364656667686970 
1 asterisk8990919293949596979899100101102
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