Isotopes of unbinilium

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

Contents

List of isotopes

No isotopes of unbinilium are known.

Nucleosynthesis

Target-projectile combinations leading to Z = 120 compound nuclei

The below table contains various combinations of targets and projectiles that could be used to form compound nuclei with Z = 120. [1]

TargetProjectileCNAttempt result
208Pb88Sr296UbnReaction yet to be attempted
238U64Ni302UbnFailure to date
237Np59Co296UbnReaction yet to be attempted
244Pu58Fe302UbnFailure to date
244Pu60Fe304UbnReaction yet to be attempted
243Am55Mn298UbnReaction yet to be attempted
245Cm54Cr299Ubn [2] Reaction yet to be attempted
248Cm54Cr302UbnFailure to date
250Cm54Cr304UbnReaction yet to be attempted
249Bk51V300UbnReaction yet to be attempted
249Cf50Ti299UbnFailure to date
250Cf50Ti300UbnReaction yet to be attempted
251Cf50Ti301UbnReaction yet to be attempted
252Cf50Ti302UbnReaction yet to be attempted
257Fm48Ca305UbnReaction yet to be attempted

Hot fusion

238U(64Ni,xn)302-xUbn

In April 2007, the team at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany attempted to create unbinilium using a 238 U target and a 64 Ni beam: [3]

238
92U
 + 64
28Ni
 → 302
120Ubn
* → no atoms

No atoms were detected, providing a limit of 1.6  pb for the cross section at the energy provided. The GSI repeated the experiment with higher sensitivity in three separate runs in April–May 2007, January–March 2008, and September–October 2008, all with negative results, reaching a cross section limit of 90 fb. [3]

244Pu(58Fe,xn)302-xUbn

Following their success in obtaining oganesson by the reaction between 249Cf and 48Ca in 2006, the team at the Joint Institute for Nuclear Research (JINR) in Dubna started experiments in March–April 2007 to attempt to create unbinilium with a 58Fe beam and a 244Pu target. [4] [5] Initial analysis revealed that no atoms of unbinilium were produced, providing a limit of 400  fb for the cross section at the energy studied. [6]

244
94Pu
 + 58
26Fe
 → 302
120Ubn
* → no atoms

The Russian team planned to upgrade their facilities before attempting the reaction again. [6]

245Cm(54Cr,xn)299-xUbn

There are indications that this reaction may be tried by the JINR in future. The expected products of the 3n and 4n channels, 296120 and 295120, could undergo five alpha decays to reach the darmstadtium isotopes 276Ds and 275Ds respectively; these darmstadtium isotopes were synthesised at the JINR in 2022 and 2023 respectively, both in the 232Th+48Ca reaction. [2] [7]

248Cm(54Cr,xn)302-xUbn

In 2011, after upgrading their equipment to allow the use of more radioactive targets, scientists at the GSI attempted the rather asymmetrical fusion reaction: [8]

248
96Cm
 + 54
24Cr
 → 302
120Ubn
* → no atoms

It was expected that the change in reaction would quintuple the probability of synthesizing unbinilium, [9] as the yield of such reactions is strongly dependent on their asymmetry. [10] Although this reaction is less asymmetric than the 249Cf+50Ti reaction, it also creates more neutron-rich unbinilium isotopes that should receive increased stability from their proximity to the shell closure at N = 184. [11] Three signals were observed in May 2011; a possible assignment to 299Ubn and its daughters was considered, [12] but could not be confirmed, [13] [14] [11] and a different analysis suggested that what was observed was simply a random sequence of events. [15]

In March 2022, Yuri Oganessian gave a seminar at the JINR considering how one could synthesise element 120 in the 248Cm+54Cr reaction. [16] In 2023, the director of the JINR, Grigory Trubnikov, stated that he hoped that the experiments to synthesise element 120 will begin in 2025. [17]

249Cf(50Ti,xn)299-xUbn

In August–October 2011, a different team at the GSI using the TASCA facility tried a new, even more asymmetrical reaction: [8] [18]

249
98Cf
 + 50
22Ti
 → 299
120Ubn
* → no atoms

Because of its asymmetry, [19] the reaction between 249Cf and 50Ti was predicted to be the most favorable practical reaction for synthesizing unbinilium, although it is also somewhat cold, and is further away from the neutron shell closure at N = 184 than any of the other three reactions attempted. No unbinilium atoms were identified, implying a limiting cross section of 200 fb. [18] Jens Volker Kratz predicted the actual maximum cross section for producing unbinilium by any of the four reactions 238U+64Ni, 244Pu+58Fe, 248Cm+54Cr, or 249Cf+50Ti to be around 0.1 fb; [20] in comparison, the world record for the smallest cross section of a successful reaction was 30 fb for the reaction 209Bi(70Zn,n)278 Nh, [10] and Kratz predicted a maximum cross section of 20 fb for producing ununennium. [20] If these predictions are accurate, then synthesizing ununennium would be at the limits of current technology, and synthesizing unbinilium would require new methods. [20]

This reaction was investigated again in April to September 2012 at the GSI. This experiment used a 249Bk target and a 50Ti beam to produce element 119, but since 249Bk decays to 249Cf with a half-life of about 327 days, both elements 119 and 120 could be searched for simultaneously:

249
97Bk
 + 50
22Ti
 → 299
119Uue
* → no atoms
249
98Cf
 + 50
22Ti
 → 299
120Ubn
* → no atoms

Neither element 119 nor element 120 was observed. This implied a limiting cross section of 65 fb for producing element 119 in these reactions, and 200 fb for element 120. [21]

In May 2021, the JINR announced plans to investigate the 249Cf+50Ti reaction in their new facility. [22] The 249Cf target would have been produced by the Oak Ridge National Laboratory in Oak Ridge, Tennessee, United States; the 50Ti beam would be produced by the Hubert Curien Pluridisciplinary Institute in Strasbourg, Alsace, France. [23] However, after the Russian invasion of Ukraine began in 2022, collaboration between the JINR and other institutes completely ceased due to sanctions. [24] Thus, the JINR's plans have since shifted to the 248Cm+54Cr reaction, where the target and projectile beam could both be made in Russia. [23] [25]

Starting from 2022, [26] plans began to be made to use the 88-inch cyclotron in the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California, United States to attempt to make new elements using 50Ti projectiles. The plan is to first test them on a plutonium target to create livermorium (element 116) in late 2023. If that is successful, an attempt to make element 120 in the 249Cf+50Ti reaction will begin, probably in 2024 at the earliest. [27] [28]

Related Research Articles

<span class="mw-page-title-main">Meitnerium</span> Chemical element, symbol Mt and atomic number 109

Meitnerium is a synthetic chemical element; it has symbol Mt and atomic number 109. It is an extremely radioactive synthetic element. The most stable known isotope, meitnerium-278, has a half-life of 4.5 seconds, although the unconfirmed meitnerium-282 may have a longer half-life of 67 seconds. The GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany, first created this element in 1982. It is named after Lise Meitner.

<span class="mw-page-title-main">Darmstadtium</span> Chemical element, symbol Ds and atomic number 110

Darmstadtium is a synthetic chemical element; it has symbol Ds and atomic number 110. It is extremely radioactive: the most stable known isotope, darmstadtium-281, has a half-life of approximately 14 seconds. Darmstadtium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research in the city of Darmstadt, Germany, after which it was named.

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. Five isotopes of livermorium are known, with mass numbers of 288 and 290–293 inclusive; the longest-lived among them is livermorium-293 with a half-life of about 60 milliseconds. A sixth possible isotope with mass number 294 has been reported but not yet confirmed.

<span class="mw-page-title-main">Unbinilium</span> Chemical element, symbol Ubn and atomic number 120

Unbinilium, also known as eka-radium or element 120, is a hypothetical chemical element; it has symbol Ubn and atomic number 120. Unbinilium and Ubn are the temporary systematic IUPAC name and symbol, 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 an s-block element, an alkaline earth metal, and the second element in the eighth period. It has attracted attention because of some predictions that it may be in the island of stability.

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.

Tennessine is a synthetic chemical element; it has symbol Ts and atomic number 117. It has the second-highest atomic number and joint-highest atomic mass of all known elements, and is the penultimate element of the 7th period of the periodic table.

An extended periodic table theorizes about chemical elements beyond those currently known and proven. The element with the highest atomic number known is oganesson (Z = 118), which completes the seventh period (row) in the periodic table. All elements in the eighth period and beyond thus remain purely hypothetical.

Flerovium is a superheavy synthetic chemical element; it has symbol Fl and atomic number 114. It is an extremely radioactive synthetic element, named after the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research in Dubna, Russia, where the element was discovered in 1999. The lab's name, in turn, honours Russian physicist Georgy Flyorov. IUPAC adopted the name on 30 May 2012. The name and symbol had previously been proposed for element 102 (nobelium), but was not accepted by IUPAC at that time.

<span class="mw-page-title-main">Nihonium</span> Chemical element, symbol Nh and atomic number 113

Nihonium is a synthetic chemical element; it has symbol Nh and atomic number 113. It is extremely radioactive: its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block. It is a member of period 7 and group 13.

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).

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 1–4 isomers. The most stable isotope of hassium cannot be determined based on existing data due to uncertainty that arises from the low number of measurements. The half-lives of 269Hs and 271Hs are about 12 seconds, whereas that of 270Hs is about 7.6 seconds. It is also possible that 277mHs is more stable than these, with its half-life likely being 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.

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 6 known radioisotopes ; the longest-lived isotope is 285Cn with a half-life of 30 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 an artificial 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 five known radioisotopes, with mass numbers 288 and 290–293, 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 70 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.

Ununennium (119Uue) has not yet been synthesised, so all data would be theoretical 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. ↑ Isospin dependence in heavy-element synthesis in fusion-evaporation reactions with neutron-rich radioactive ion-beams, A. Yakushev et al.
  2. 1 2 "Superheavy Element Factory: overview of obtained results". Joint Institute for Nuclear Research. 24 August 2023. Retrieved 7 December 2023.
  3. 1 2 Hoffman, S.; et al. (2008). Probing shell effects at Z = 120 and N = 184 (Report). GSI Scientific Report. p. 131.
  4. ↑ "A New Block on the Periodic Table" (PDF). Lawrence Livermore National Laboratory. April 2007. Retrieved 2008-01-18.
  5. ↑ Itkis, M. G.; Oganessian, Yu. Ts. (2007). "Synthesis of New Nuclei and Study of Nuclear Properties and Heavy-Ion Reaction Mechanisms". jinr.ru. Joint Institute for Nuclear Research. Retrieved 23 September 2016.
  6. 1 2 Oganessian, Yu. Ts.; Utyonkov, V.; Lobanov, Yu.; et al. (2009). "Attempt to produce element 120 in the 244Pu+58Fe reaction". Phys. Rev. C. 79 (2). 024603. Bibcode:2009PhRvC..79b4603O. doi:10.1103/PhysRevC.79.024603.
  7. ↑ "New darmstadtium isotope discovered at Superheavy Element Factory". Joint Institute for Nuclear Research. 27 February 2023. Retrieved 29 March 2023.
  8. 1 2 Düllmann, C. E. (20 October 2011). "Superheavy Element Research: News from GSI and Mainz" . Retrieved 23 September 2016.
  9. ↑ GSI (5 April 2012). "Searching for the island of stability". www.gsi.de. GSI. Retrieved 23 September 2016.
  10. 1 2 Zagrebaev, Karpov & Greiner 2013.
  11. 1 2 Hofmann, S.; Heinz, S.; Mann, R.; et al. (2016). "Review of even element super-heavy nuclei and search for element 120". The European Physical Journal A. 2016 (52): 180. Bibcode:2016EPJA...52..180H. doi:10.1140/epja/i2016-16180-4. S2CID   124362890.
  12. ↑ Hofmann, S.; Heinz, S.; Mann, R.; et al. (2016). "Remarks on the Fission Barriers of SHN and Search for Element 120". In Peninozhkevich, Yu. E.; Sobolev, Yu. G. (eds.). Exotic Nuclei: EXON-2016 Proceedings of the International Symposium on Exotic Nuclei. Exotic Nuclei. pp. 155–164. ISBN   9789813226555.
  13. ↑ Adcock, Colin (2 October 2015). "Weighty matters: Sigurd Hofmann on the heaviest of nuclei". JPhys+. Journal of Physics G: Nuclear and Particle Physics. Retrieved 23 September 2016.
  14. ↑ Hofmann, Sigurd (August 2015). "Search for Isotopes of Element 120 on the Island of SHN". Exotic Nuclei: 213–224. Bibcode:2015exon.conf..213H. doi:10.1142/9789814699464_0023. ISBN   978-981-4699-45-7.
  15. ↑ Heßberger, F. P.; Ackermann, D. (2017). "Some critical remarks on a sequence of events interpreted to possibly originate from a decay chain of an element 120 isotope". The European Physical Journal A. 53 (123): 123. Bibcode:2017EPJA...53..123H. doi:10.1140/epja/i2017-12307-5. S2CID   125886824.
  16. ↑ JINR (29 March 2022). "At seminar on synthesis of element 120". jinr.ru. JINR. Retrieved 17 April 2022.
  17. ↑ Mayer, Anastasiya (31 May 2023). "«Большинство наших партнеров гораздо мудрее политиков»" ["Most of our partners are much wiser than politicians"]. Vedomosti (in Russian). Retrieved 15 August 2023. В этом году мы фактически завершаем подготовительную серию экспериментов по отладке всех режимов ускорителя и масс-спектрометров для синтеза 120-го элемента. Научились получать высокие интенсивности ускоренного хрома и титана. Научились детектировать сверхтяжелые одиночные атомы в реакциях с минимальным сечением. Теперь ждем, когда закончится наработка материала для мишени на реакторах и сепараторах у наших партнеров в «Росатоме» и в США: кюрий, берклий, калифорний. Надеюсь, что в 2025 г. мы полноценно приступим к синтезу 120-го элемента.
  18. 1 2 Yakushev, A. (2012). "Superheavy Element Research at TASCA" (PDF). asrc.jaea.go.jp. Retrieved 23 September 2016.
  19. ↑ Siwek-Wilczyńska, K.; Cap, T.; Wilczyński, J. (April 2010). "How can one synthesize the element Z = 120?". International Journal of Modern Physics E. 19 (4): 500. Bibcode:2010IJMPE..19..500S. doi:10.1142/S021830131001490X.
  20. 1 2 3 Kratz, J. V. (5 September 2011). The Impact of Superheavy Elements on the Chemical and Physical Sciences (PDF). 4th International Conference on the Chemistry and Physics of the Transactinide Elements. Retrieved 27 August 2013.
  21. ↑ Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch. E.; et al. (December 2020). "Search for elements 119 and 120" (PDF). Physical Review C. 102 (6): 064602. Bibcode:2020PhRvC.102f4602K. doi:10.1103/PhysRevC.102.064602. hdl:1885/289860. S2CID   229401931 . Retrieved 25 January 2021.
  22. ↑ Sokolova, Svetlana; Popeko, Andrei (24 May 2021). "How are new chemical elements born?". jinr.ru. JINR. Retrieved 4 November 2021. Previously, we worked mainly with calcium. This is element 20 in the Periodic Table. It was used to bombard the target. And the heaviest element that can be used to make a target is californium, 98. Accordingly, 98 + 20 is 118. That is, to get element 120, we need to proceed to the next particle. This is most likely titanium: 22 + 98 = 120.

    There is still much work to adjust the system. I don't want to get ahead of myself, but if we can successfully conduct all the model experiments, then the first experiments on the synthesis of element 120 will probably start this year.
  23. 1 2 Riegert, Marion (19 July 2021). "In search of element 120 in the periodic table of elements". en.unistra.fr. University of Strasbourg . Retrieved 20 February 2022.
  24. ↑ Ahuja, Anjana (18 October 2023). "Even the periodic table must bow to the reality of war". Financial Times. Retrieved 20 October 2023.
  25. ↑ "В ЛЯР ОИЯИ впервые в мире синтезирован ливерморий-288" [Livermorium-288 was synthesized for the first time in the world at FLNR JINR] (in Russian). Joint Institute for Nuclear Research. 23 October 2023. Retrieved 18 November 2023.
  26. ↑ Gates, J.; Pore, J.; Crawford, H.; Shaughnessy, D.; Stoyer, M. A. (25 October 2022). "The Status and Ambitions of the US Heavy Element Program". osti.gov. doi:10.2172/1896856. OSTI   1896856. S2CID   253391052 . Retrieved 13 November 2022.
  27. ↑ Chapman, Kit (10 October 2023). "Berkeley Lab to lead US hunt for element 120 after breakdown of collaboration with Russia". Chemistry World. Retrieved 20 October 2023.
  28. ↑ Biron, Lauren (16 October 2023). "Berkeley Lab to Test New Approach to Making Superheavy Elements". lbl.gov. Lawrence Berkeley National Laboratory . Retrieved 20 October 2023.

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