Editing Hassium (section)

=== Reports ===

Synthesis of element{{spaces}}108 was first attempted in 1978 by a team led by Oganessian at JINR. The team used a reaction that would generate element{{spaces}}108, specifically, the isotope {{sup|270}}108,{{Efn|The superscript number to the left of a chemical symbol refers to the mass of the nuclide; for instance, {{sup|48}}Ca is [[calcium-48]]. In superheavy element research, elements that have not gotten a name and a symbol, are often called by their atomic number in lieu of symbols; if a symbol has been assigned and the number is to be displayed, it is written in subscript to the left of the symbol. {{sup|270}}108 would be {{sup|270}}Hs or {{nuclide|hassium|270}} or hassium-270 in modern nomenclature.}} from fusion of [[radium]] (specifically, the isotope {{nowrap|{{Nuclide|radium|226}})}} and [[calcium]] {{nowrap|({{Nuclide|calcium|48}})}}. The researchers were uncertain in interpreting their data, and their paper did not unambiguously claim to have discovered the element.<ref>{{cite report |first1=Yu. Ts. |last1=Oganessian |first2=G. M. |last2=Ter-Akopian |first3=A. A. |last3=Pleve |display-authors=etal |year=1978 |title=Опыты по синтезу 108 элемента в реакции {{sup|226}}Ra + {{sup|48}}Ca |trans-title=Experiments on synthesis of element{{spaces}}108 in the {{sup|226}}Ra+{{sup|48}}Ca reaction |publisher=[[Joint Institute for Nuclear Research]] |url=https://inis.iaea.org/collection/NCLCollectionStore/_Public/13/643/13643968.pdf |access-date=8 June 2018 |language=ru |archive-date=15 March 2020 |archive-url=https://web.archive.org/web/20200315080910/https://inis.iaea.org/collection/NCLCollectionStore/_Public/13/643/13643968.pdf |url-status=live }}</ref> The same year, another team at JINR investigated the possibility of synthesis of element{{spaces}}108 in reactions between [[lead]] {{nowrap|({{Nuclide|lead|208}})}} and [[iron]] {{nowrap|({{Nuclide|iron|58}})}}; they were uncertain in interpreting the data, suggesting the possibility that element{{spaces}}108 had not been created.<ref>{{Cite report|last1=Orlova|first1=O. A.|last2=Pleve|first2=A. A.|last3=Ter-Akop'yan|first3=G. M.|last4=Tret'yakova|first4=S. P.|last5=Chepigin|first5=V. I.|last6=Cherepanov|first6=E. A.|display-authors=3|date=1979|title=Опыты по синтезу 108 элемента в реакции {{sup|208}}Pb + {{sup|58}}Fe|trans-title=Experiments on the synthesis of element 108 in the {{sup|208}}Pb + {{sup|58}}Fe reaction|url=https://inis.iaea.org/collection/NCLCollectionStore/_Public/10/486/10486434.pdf|language=ru|publisher=Joint Institute for Nuclear Research|access-date=2020-08-28|archive-date=11 March 2020|archive-url=https://web.archive.org/web/20200311041124/https://inis.iaea.org/collection/NCLCollectionStore/_Public/10/486/10486434.pdf|url-status=live}}</ref>
[[File:GSI, Darmstadt, Juli 2015 (4).JPG|thumb|upright=1.15|alt=GSI's particle accelerator UNILAC|GSI's linear [[particle accelerator]] UNILAC, where hassium was discovered<ref>{{Cite web|title=Timeline—GSI|url=https://www.gsi.de/en/about_us/50_years_gsi/timeline_1969_2019.htm|publisher=[[GSI Helmholtz Centre for Heavy Ion Research]]|access-date=2019-12-10|archive-date=5 August 2020|archive-url=https://web.archive.org/web/20200805184050/https://www.gsi.de/en/about_us/50_years_gsi/timeline_1969_2019.htm|url-status=live}}</ref> and where its chemistry was first observed<ref>{{Cite news|last=Preuss|first=P.|date=2001|url=https://www2.lbl.gov/Science-Articles/Archive/108-chemistry.html|title=Hassium becomes heaviest element to have its chemistry studied|publisher=Lawrence Berkeley National Laboratory|access-date=2019-12-10|archive-date=10 December 2019|archive-url=https://web.archive.org/web/20191210155135/https://www2.lbl.gov/Science-Articles/Archive/108-chemistry.html|url-status=live}}</ref>|left]]

In 1983, new experiments were performed at JINR.{{sfn|Barber et al.|1993|p=1790}} The experiments probably resulted in the synthesis of element{{spaces}}108; [[bismuth]] {{nowrap|({{Nuclide|bismuth|209}})}} was bombarded with [[manganese]] {{nowrap|({{Nuclide|manganese|55}})}} to obtain {{sup|263}}108, lead ({{sup|207, 208}}Pb) was bombarded with iron ({{sup|58}}Fe) to obtain {{sup|264}}108, and [[californium]] {{nowrap|({{Nuclide|californium|249}})}} was bombarded with [[neon]] {{nowrap|({{Nuclide|neon|22}})}} to obtain {{sup|270}}108.<ref name="Emsley2011" /> These experiments were not claimed as a discovery and Oganessian announced them in a conference rather than in a written report.{{sfn|Barber et al.|1993|p=1790}}

In 1984, JINR researchers in Dubna performed experiments set up identically to the previous ones; they bombarded bismuth and lead targets with ions of manganese and iron, respectively. Twenty-one spontaneous fission events were recorded; the researchers concluded they were caused by {{sup|264}}108.{{sfn|Barber et al.|1993|p=1791}}

Later in 1984, a research team led by [[Peter Armbruster]] and [[Gottfried Münzenberg]] at [[Gesellschaft für Schwerionenforschung]] (GSI; ''Institute for Heavy Ion Research'') in [[Darmstadt]], [[Hesse]], [[West Germany]], tried to create element{{spaces}}108. The team bombarded a lead ({{sup|208}}Pb) target with accelerated iron ({{sup|58}}Fe) nuclei.<ref name="84Mu01">{{Cite journal|doi=10.1007/BF01421260|title=The identification of element 108|year=1984|author=Münzenberg, G.|journal=Zeitschrift für Physik A|volume=317|pages=235|last2=Armbruster|first2=P.|last3=Folger|first3=H.|last4=Heßberger|first4=P. F.|last5=Hofmann|first5=S.|last6=Keller|first6=J.|last7=Poppensieker|first7=K.|last8=Reisdorf|first8=W.|last9=Schmidt|first9=K. -H.|bibcode = 1984ZPhyA.317..235M|issue=2 }}</ref> GSI's experiment to create element{{spaces}}108 was delayed until after their creation of [[meitnerium|element{{spaces}}109]] in 1982, as prior calculations had suggested that [[even and odd atomic nuclei#Even proton, even neutron|even–even]] isotopes of element{{spaces}}108 would have spontaneous fission half-lives of less than one [[microsecond]], making them difficult to detect and identify.<ref name="GSIrecollection" /> The element{{spaces}}108 experiment finally went ahead after {{sup|266}}109 had been synthesized and was found to decay by alpha emission, suggesting that isotopes of element{{spaces}}108 would do likewise, and this was corroborated by an experiment aimed at synthesizing isotopes of element{{spaces}}106. GSI reported synthesis of three atoms of {{sup|265}}108. Two years later, they reported synthesis of one atom of the even–even {{sup|264}}108.<ref name="GSIrecollection">{{cite journal |last1=Hofmann |first1=S. |date=2016 |title=The discovery of elements 107 to 112 |url=https://www.epj-conferences.org/articles/epjconf/pdf/2016/26/epjconf-NS160-06001.pdf |journal=EPJ Web Conf. |volume=131 |doi=10.1051/epjconf/201613106001 |access-date=23 September 2019 |pages=4–5 |bibcode=2016EPJWC.13106001H |doi-access=free |archive-date=1 February 2021 |archive-url=https://web.archive.org/web/20210201101405/https://www.epj-conferences.org/articles/epjconf/pdf/2016/26/epjconf-NS160-06001.pdf |url-status=live }}</ref>