Isotopes of moscovium

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Isotopes of moscovium  (115Mc)
Main isotopes Decay
abun­dance half-life (t1/2) mode pro­duct
286Mc synth 20 ms [1] α 282Nh
287Mcsynth38 msα 283Nh
288Mcsynth193 msα 284Nh
289Mcsynth250 ms [2] [3] α 285Nh
290Mcsynth650 ms [2] [3] α 286Nh

Moscovium (115Mc) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no known stable isotopes. The first isotope to be synthesized was 288Mc in 2004. There are five known radioisotopes from 286Mc to 290Mc. The longest-lived isotope is 290Mc with a half-life of 0.65 seconds.

Contents

List of isotopes


The isotopes undergo alpha decay into the corresponding isotope of nihonium, with half-lives increasing as neutron numbers increase.

Nuclide
 Z N Isotopic mass (Da) [4]
[n 1] [n 2] 		Half-life [5]
Decay
mode [5]
Daughter
isotope
Spin and
parity [5]
286Mc [6] 11517120+98
−9 ms		α282Nh
287Mc115172287.19082(48)#38+22
−10 ms [6] 		α283Nh
288Mc115173288.19288(58)#193+15
−13 ms [6] 		α284Nh
289Mc115174289.19397(83)#250+51
−35 ms [6] 		α285Nh
290Mc [n 3] 115175290.19624(64)#650+490
−200 ms
[0.84(36) s]		α286Nh
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).
  3. ↑ Not directly synthesized, created as decay product of 294Ts

Nucleosynthesis

Chronology of isotope discovery
IsotopeYear discoveredDiscovery reaction
286Mc2021243Am(48Ca,5n)
287Mc2003243Am(48Ca,4n)
288Mc2003243Am(48Ca,3n)
289Mc2009249Bk(48Ca,4n) [2]
290Mc2009249Bk(48Ca,3n) [2]

Target-projectile combinations

The table below contains various combinations of targets and projectiles which could be used to form compound nuclei with Z = 115. Each entry is a combination for which calculations have provided estimates for cross section yields from various neutron evaporation channels. The channel with the highest expected yield is given.

TargetProjectileCNAttempt result
208Pb75As283McReaction yet to be attempted
209Bi76Ge285McReaction yet to be attempted
238U51V289McFailure to date
243Am48Ca291Mc [7] [8] Successful reaction
241Am48Ca289McPlanned reaction
243Am44Ca287McReaction yet to be attempted

Hot fusion

Hot fusion reactions are processes that create compound nuclei at high excitation energy (~40–50 MeV, hence "hot"), leading to a reduced probability of survival from fission. The excited nucleus then decays to the ground state via the emission of 3–5 neutrons. Fusion reactions utilizing 48Ca nuclei usually produce compound nuclei with intermediate excitation energies (~30–35 MeV) and are sometimes referred to as "warm" fusion reactions. This leads, in part, to relatively high yields from these reactions.

238U(51V,xn)289−xMc

There are strong indications that this reaction was performed in late 2004 as part of a uranium(IV) fluoride target test at the GSI. No reports have been published suggesting that no product atoms were detected, as anticipated by the team. [9]

243Am(48Ca,xn)291−xMc (x=2,3,4,5)

This reaction was first performed by the team in Dubna in July–August 2003. In two separate runs they were able to detect 3 atoms of 288Mc and a single atom of 287Mc. The reaction was studied further in June 2004 in an attempt to isolate the descendant 268Db from the 288Mc decay chain. After chemical separation of a +4/+5 fraction, 15 SF decays were measured with a lifetime consistent with 268Db. In order to prove that the decays were from dubnium-268, the team repeated the reaction in August 2005 and separated the +4 and +5 fractions and further separated the +5 fractions into tantalum-like and niobium-like ones. Five SF activities were observed, all occurring in the niobium-like fractions and none in the tantalum-like fractions, proving that the product was indeed isotopes of dubnium.

In a series of experiments between October 2010 – February 2011, scientists at the FLNR studied this reaction at a range of excitation energies. They were able to detect 21 atoms of 288Mc and one atom of 289Mc, from the 2n exit channel. This latter result was used to support the synthesis of tennessine. The 3n excitation function was completed with a maximum at ~8  pb. The data was consistent with that found in the first experiments in 2003.

This reaction was run again at five different energies in 2021 to test the new gas-filled separator at Dubna's SHE-factory. They detected 6 chains of 289Mc, 58 chains of 288Mc, and 2 chains of 287Mc. For the first time the 5n channel was observed with 2 atoms of 286Mc. [10]

242Pu(50Ti,pxn)291−xMc (x=2)

This reaction was studied by the team in Dubna in 2024. For the first time, a pxn reaction was successful with actinide targets and 48Ca/50Ti/54Cr projectiles, producing one atom of the known 289Mc in the p2n channel (evaporating one proton and two neutrons). [11]

Reaction yields

The table below provides cross-sections and excitation energies for hot fusion reactions producing moscovium isotopes directly. Data in bold represent maxima derived from excitation function measurements. + represents an observed exit channel.

ProjectileTargetCN2n3n4n5n
48Ca243Am291Mc3.7 pb, 39.0 MeV0.9 pb, 44.4 MeV

Theoretical calculations

Decay characteristics

Theoretical calculations using a quantum-tunneling model support the experimental alpha-decay half-lives. [12]

Evaporation residue cross sections

The table below contains various target-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.

MD = multi-dimensional; DNS = Di-nuclear system; σ = cross section

TargetProjectileCNChannel (product)σmaxModelRef
243Am48Ca291Mc3n (288Mc)3 pbMD [7]
243Am48Ca291Mc4n (287Mc)2 pbMD [7]
243Am48Ca291Mc3n (288Mc)1 pbDNS [8]
242Am48Ca290Mc3n (287Mc)2.5 pbDNS [8]
241Am48Ca289Mc4n (285Mc)1.04 pbDNS [13]

Related Research Articles

Livermorium is a synthetic chemical element; it has symbol Lv and atomic number 116. It is an extremely radioactive element that has only been created in a laboratory setting and has not been observed in nature. The element is named after the Lawrence Livermore National Laboratory in the United States, which collaborated with the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, to discover livermorium during experiments conducted between 2000 and 2006. The name of the laboratory refers to the city of Livermore, California, where it is located, which in turn was named after the rancher and landowner Robert Livermore. The name was adopted by IUPAC on May 30, 2012. Six isotopes of livermorium are known, with mass numbers of 288–293 inclusive; the longest-lived among them is livermorium-293 with a half-life of about 80 milliseconds. A seventh possible isotope with mass number 294 has been reported but not yet confirmed.

<span class="mw-page-title-main">Island of stability</span> Predicted set of isotopes of relatively more stable superheavy elements

In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclides, separated from known stable and long-lived primordial radionuclides. Its theoretical existence is attributed to stabilizing effects of predicted "magic numbers" of protons and neutrons in the superheavy mass region.

Moscovium is a synthetic chemical element; it has symbol Mc and atomic number 115. It was first synthesized in 2003 by a joint team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. In December 2015, it was recognized as one of four new elements by the Joint Working Party of international scientific bodies IUPAC and IUPAP. On 28 November 2016, it was officially named after the Moscow Oblast, in which the JINR is situated.

Unbibium, also known as element 122 or eka-thorium, is a hypothetical chemical element; it has placeholder symbol Ubb and atomic number 122. Unbibium and Ubb are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to follow unbiunium as the second element of the superactinides and the fourth element of the 8th period. Similarly to unbiunium, it is expected to fall within the range of the island of stability, potentially conferring additional stability on some isotopes, especially 306Ubb which is expected to have a magic number of neutrons (184).

Dubnium (105Db) is a synthetic element, thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 261Db in 1968. Thirteen radioisotopes are known, ranging from 255Db to 270Db, along with one isomer (257mDb); two more isomers have been reported but are unconfirmed. The longest-lived known isotope is 268Db with a half-life of 16 hours.

Seaborgium (106Sg) is a synthetic element and so has no stable isotopes. A standard atomic weight cannot be given. The first isotope to be synthesized was 263Sg in 1974. There are thirteen known radioisotopes from 258Sg to 271Sg and five known isomers. The longest-lived isotopes are 267Sg with a half-life of 9.8 minutes and 269Sg with a half-life of 5 minutes. Due to a low number of measurements, and the consequent overlapping measurement uncertainties at the confidence level corresponding to one standard deviation, a definite assignment of the most stable isotope cannot be made.

Bohrium (107Bh) is an artificial element. Like all artificial elements, it has no stable isotopes, and a standard atomic weight cannot be given. The first isotope to be synthesized was 262Bh in 1981. There are 11 known isotopes ranging from 260Bh to 274Bh, and 1 isomer, 262mBh. The longest-lived isotope is 270Bh with a half-life of 2.4 minutes, although the unconfirmed 278Bh may have an even longer half-life of about 690 seconds.

Hassium (108Hs) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 265Hs in 1984. There are 13 known isotopes from 263Hs to 277Hs and up to six isomers. The most stable known isotope is 271Hs, with a half-life of about 46 seconds, though this assignment is not definite due to uncertainty arising from a low number of measurements. The isotopes 269Hs and 270Hs respectively have half-lives of about 12 seconds and 7.6 seconds. It is also possible that the isomer 277mHs is more stable than these, with a reported half-life 130±100 seconds, but only one event of decay of this isotope has been registered as of 2016.

Meitnerium (109Mt) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 266Mt in 1982, and this is also the only isotope directly synthesized; all other isotopes are only known as decay products of heavier elements. There are eight known isotopes, from 266Mt to 278Mt. There may also be two isomers. The longest-lived of the known isotopes is 278Mt with a half-life of 8 seconds. The unconfirmed heavier 282Mt appears to have an even longer half-life of 67 seconds.

Darmstadtium (110Ds) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 269Ds in 1994. There are 11 known radioisotopes from 267Ds to 281Ds and 2 or 3 known isomers. The longest-lived isotope is 281Ds with a half-life of 14 seconds. However, the unconfirmed 282Ds might have an even longer half-life of 67 seconds.

Roentgenium (111Rg) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 272Rg in 1994, which is also the only directly synthesized isotope; all others are decay products of heavier elements. There are seven known radioisotopes, having mass numbers of 272, 274, and 278–282. The longest-lived isotope is 282Rg with a half-life of about 2 minutes, although the unconfirmed 283Rg and 286Rg may have longer half-lives of about 5.1 minutes and 10.7 minutes respectively.

Copernicium (112Cn) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 277Cn in 1996. There are seven known radioisotopes ; the longest-lived isotope is 285Cn with a half-life of 30 seconds.

Nihonium (113Nh) is a synthetic element. Being synthetic, a standard atomic weight cannot be given and like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 284Nh as a decay product of 288Mc in 2003. The first isotope to be directly synthesized was 278Nh in 2004. There are 6 known radioisotopes from 278Nh to 286Nh, along with the unconfirmed 287Nh and 290Nh. The longest-lived isotope is 286Nh with a half-life of 9.5 seconds.

Flerovium (114Fl) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 289Fl in 1999. Flerovium has six known isotopes, along with the unconfirmed 290Fl, and possibly two nuclear isomers. The longest-lived isotope is 289Fl with a half-life of 1.9 seconds, but 290Fl may have a longer half-life of 19 seconds.

Livermorium (116Lv) is a synthetic element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 293Lv in 2000. There are six known radioisotopes, with mass numbers 288–293, as well as a few suggestive indications of a possible heavier isotope 294Lv. The longest-lived known isotope is 293Lv with a half-life of 53 ms.

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 isotopes to be synthesized were 293Ts and 294Ts in 2009. The longer-lived isotope is 294Ts with a half-life of 51 ms.

Oganesson (118Og) is a synthetic element created in particle accelerators, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first and only isotope to be synthesized was 294Og in 2002 and 2005; it has a half-life of 0.7 milliseconds.

Ununennium (119Uue) has not yet been synthesised, so there is no experimental data and a standard atomic weight cannot be given. Like all synthetic elements, it would have no stable isotopes.

Unbinilium (120Ubn) has not yet been synthesised, so there is no experimental data and a standard atomic weight cannot be given. Like all synthetic elements, it would have no stable isotopes.

Unbiunium, also known as eka-actinium or element 121, is a hypothetical chemical element; it has symbol Ubu and atomic number 121. Unbiunium and Ubu are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to be the first of the superactinides, and the third element in the eighth period. It has attracted attention because of some predictions that it may be in the island of stability. It is also likely to be the first of a new g-block of elements.

References

  1. ↑ Kovrizhnykh, N. (27 January 2022). "Update on the experiments at the SHE Factory". Flerov Laboratory of Nuclear Reactions. Retrieved 28 February 2022.
  2. 1 2 3 4 Oganessian, Yuri Ts.; Abdullin, F. Sh.; Bailey, P. D.; et al. (2010-04-09). "Synthesis of a New Element with Atomic Number Z=117". Physical Review Letters. 104 (142502). American Physical Society: 142502. Bibcode:2010PhRvL.104n2502O. doi:10.1103/PhysRevLett.104.142502. PMID   20481935.
  3. 1 2 Oganessian, Y.T. (2015). "Super-heavy element research". Reports on Progress in Physics. 78 (3): 036301. Bibcode:2015RPPh...78c6301O. doi:10.1088/0034-4885/78/3/036301. PMID   25746203. S2CID   37779526.
  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. 1 2 3 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.
  6. 1 2 3 4 Oganessian, Yu. Ts.; Utyonkov, V. K.; Kovrizhnykh, N. D.; et al. (2022). "New isotope 286Mc produced in the 243Am+48Ca reaction". Physical Review C. 106 (64306): 064306. Bibcode:2022PhRvC.106f4306O. doi: 10.1103/PhysRevC.106.064306 . S2CID   254435744.
  7. 1 2 3 Zagrebaev, V. (2004). "Fusion-fission dynamics of super-heavy element formation and decay" (PDF). Nuclear Physics A. 734: 164–167. Bibcode:2004NuPhA.734..164Z. doi:10.1016/j.nuclphysa.2004.01.025.
  8. 1 2 3 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): 33–51. arXiv: 0803.1117 . Bibcode:2009NuPhA.816...33F. doi:10.1016/j.nuclphysa.2008.11.003. S2CID   18647291.
  9. ↑ "List of experiments 2000–2006". Univerzita Komenského v Bratislave. Archived from the original on July 23, 2007.
  10. ↑ "Both neutron properties and new results at SHE Factory".
  11. ↑ Ibadullayev, Dastan (2024). "Synthesis and study of the decay properties of isotopes of superheavy element Lv in Reactions 238U + 54Cr and 242Pu + 50Ti". jinr.ru. Joint Institute for Nuclear Research . Retrieved 2 November 2024.
  12. ↑ C. Samanta; P. Roy Chowdhury; D. N. Basu (2007). "Predictions of alpha decay half lives of heavy and superheavy elements". Nucl. Phys. A. 789 (1–4): 142–154. arXiv: nucl-th/0703086 . Bibcode:2007NuPhA.789..142S. doi:10.1016/j.nuclphysa.2007.04.001. S2CID   7496348.
  13. ↑ Zhu, L.; Su, J.; Zhang, F. (2016). "Influence of the neutron numbers of projectile and target on the evaporation residue cross sections in hot fusion reactions". Physical Review C . 93 (6): 064610. Bibcode:2016PhRvC..93f4610Z. doi:10.1103/PhysRevC.93.064610.
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