Isotopes of darmstadtium#Darmstadtium-278

{{Anchor|Darmstadtium-268|Darmstadtium-272|Darmstadtium-274|Darmstadtium-278|Darmstadtium-283|Darmstadtium-284}}

{{Isotopes table

|symbol=Ds

|refs=NUBASE2020, AME2020 II

|notes=m, unc(), mass#, spin#, spin(), SF

}}

|-id=Darmstadtium-267

| ²⁶⁷DsUnconfirmed isotope

| style="text-align:right" | 110

| style="text-align:right" | 157

| 267.14373(22)#

| {{val|2.8|13.0|1.3|u=μs}}
[{{val|10|(8)|u=us}}]

| α

| ²⁶³Hs

| 3/2+#

|-id=Darmstadtium-269

| ²⁶⁹Ds

| style="text-align:right" | 110

| style="text-align:right" | 159

| 269.14475(3)

| {{val|170|160|60|u=μs}}
[{{val|230|(110)|u=us}}]

| α

| ²⁶⁵Hs

|

|-id=Darmstadtium-270

| ²⁷⁰Ds

| style="text-align:right" | 110

| style="text-align:right" | 160

| 270.14459(4)

| {{val|205|(48)|u=μs}}

| α

| ²⁶⁶Hs

| 0+

|-id=Darmstadtium-270m

| rowspan=2 style="text-indent:1em" | ^270mDs

| rowspan=2 colspan="3" style="text-indent:2em" | 1390(60) keV

| rowspan=2|{{val|3.9|1.5|0.8|u=ms}}
[{{val|4.3|(12)|u=ms}}]

| α (70%)

| ²⁶⁶Hs

| rowspan=2|10−#

|-

| IT (30%)

| ²⁷⁰Ds

|-id=Darmstadtium-271

| rowspan=2|²⁷¹Ds

| rowspan=2 style="text-align:right" | 110

| rowspan=2 style="text-align:right" | 161

| rowspan=2|271.14595(10)#

| rowspan=2|144(53) ms

|SF (75%)

|(various)

|rowspan=2|

|-

| α (25%)

| ²⁶⁷Hs

|-id=Darmstadtium-271m

| style="text-indent:1em" | ^271mDsOrder of ground state and isomer is uncertain.

| colspan="3" style="text-indent:2em" | 68(27) keV

| {{val|1.63|0.44|0.29|u=ms}}
[{{val|1.7|(4)|u=ms}}]

| α

| ²⁶⁷Hs

|

|-id=Darmstadtium-273

| ²⁷³Ds

| style="text-align:right" | 110

| style="text-align:right" | 163

| 273.14846(15)#

| {{val|190|140|60|u=μs}}
[{{val|240|(100)|u=us}}]

| α

| ²⁶⁹Hs

|

|-id=Darmstadtium-273m

| style="text-indent:1em" | ^273mDs

| colspan="3" style="text-indent:2em" | 198(20) keV

| 120 ms

| α

| ²⁶⁹Hs

|

|-id=Darmstadtium-275

|²⁷⁵Ds

| style="text-align:right" | 110

| style="text-align:right" | 165

|275.15209(37)#

|{{val|430|290|120|u=μs}}

|α

|²⁷¹Hs

| 3/2#

|-id=Darmstadtium-276

| rowspan=2|²⁷⁶Ds{{cite journal |title=New isotope ²⁷⁶Ds and its decay products ²⁷²Hs and ²⁶⁸Sg from the ²³²Th + ⁴⁸Ca reaction |last1=Oganessian |first1=Yu. Ts. |last2=Utyonkov |first2=V. K. |last3=Shumeiko |first3=M. V. |display-authors=et al. |date=2023 |journal=Physical Review C |volume=108 |number=24611 |page=024611 |doi=10.1103/PhysRevC.108.024611|bibcode=2023PhRvC.108b4611O |s2cid=261170871 }}

| rowspan=2 style="text-align:right" | 110

| rowspan=2 style="text-align:right" | 166

| rowspan=2|276.15302(59)#

| rowspan=2|{{val|150|100|40|u=us}}

| SF (57%)

| (various)

| rowspan=2|0+

|-

| α (43%)

| ²⁷²Hs

|-id=Darmstadtium-277

| ²⁷⁷DsNot directly synthesized, occurs in decay chain of ²⁸⁵Fl

| style="text-align:right" | 110

| style="text-align:right" | 167

| 277.15576(42)#

| {{val|4.0|1.8|1.0|u=ms}}{{cite web |last1=Kovrizhnykh |first1=N.D. |title=On the way to the synthesis of new elements: 119 and 120 |url=https://indico.gsi.de/event/21160/contributions/85071/attachments/49852/75915/TASCA25_Contribution_Kovrizhnykh.pdf |access-date=1 June 2025}}
[{{val|6|(3)|u=ms}}]

| α

| ²⁷³Hs

|

|-id=Darmstadtium-279

| rowspan=2|²⁷⁹DsNot directly synthesized, occurs as decay product of ²⁸³Cn

| rowspan=2 style="text-align:right" | 110

| rowspan=2 style="text-align:right" | 169

| rowspan=2|279.15998(65)#

| rowspan=2|{{val|186|21|17|u=ms}}{{cite journal |title=Investigation of ⁴⁸Ca-induced reactions with ²⁴²Pu and ²³⁸U targets at the JINR Superheavy Element Factory |journal=Physical Review C |volume=106 |number=24612 |year=2022 |first1=Yu. Ts. |last1=Oganessian |first2=V. K. |last2=Utyonkov |first3=D. |last3=Ibadullayev |page=024612 |display-authors=et al. |doi= 10.1103/PhysRevC.106.024612|bibcode=2022PhRvC.106b4612O |osti=1883808 |s2cid=251759318 }}

| SF (87%)

| (various)

| rowspan=2|

|-

| α (13%)

| ²⁷⁵Hs

|-id=Darmstadtium-280

| ²⁸⁰DsNot directly synthesized, occurs in decay chain of ²⁸⁸Fl

| style="text-align:right" | 110

| style="text-align:right" | 170

| 280.16138(80)#

| {{val|360|172|16|u=μs}}{{Cite journal |doi = 10.1103/PhysRevLett.126.032503|title = Spectroscopy along Flerovium Decay Chains: Discovery of ²⁸⁰Ds and an Excited State in ²⁸²Cn|journal = Physical Review Letters|volume = 126|pages = 032503|year = 2021|last1 = Såmark-Roth|first1 = A.|last2 = Cox|first2 = D. M.|last3 = Rudolph|first3 = D.|last4 = Sarmento|first4 = L. G.|last5 = Carlsson|first5 = B. G.|last6 = Egido|first6 = J. L.|last7 = Golubev|first7 = P|last8 = Heery|first8 = J.|last9 = Yakushev|first9 = A.|last10 = Åberg|first10 = S.|last11 = Albers|first11 = H. M.|last12 = Albertsson|first12 = M.|last13 = Block|first13 = M.|last14 = Brand|first14 = H.|last15 = Calverley|first15 = T.|last16 = Cantemir|first16 = R.|last17 = Clark|first17 = R. M.|last18 = Düllmann|first18 = Ch. E.|last19 = Eberth|first19 = J.|last20 = Fahlander|first20 = C.|last21 = Forsberg|first21 = U.|last22 = Gates|first22 = J. M.|last23 = Giacoppo|first23 = F.|last24 = Götz|first24 = M.|last25 = Hertzberg|first25 = R.-D.|last26 = Hrabar|first26 = Y.|last27 = Jäger|first27 = E.|last28 = Judson|first28 = D.|last29 = Khuyagbaatar|first29 = J.|last30 = Kindler|first30 = B.| issue=3 | pmid=33543956 | bibcode=2021PhRvL.126c2503S |display-authors = 3|doi-access = free|hdl = 10486/705608|hdl-access = free}}{{Cite journal |arxiv = 1502.03030|doi = 10.1016/j.nuclphysa.2016.04.025|title = Recoil-α-fission and recoil-α–α-fission events observed in the reaction 48Ca + 243Am|journal = Nuclear Physics A|volume = 953|pages = 117–138|year = 2016|last1 = Forsberg|first1 = U.|last2 = Rudolph|first2 = D.|last3 = Andersson|first3 = L.-L.|last4 = Di Nitto|first4 = A.|last5 = Düllmann|first5 = Ch.E.|last6 = Fahlander|first6 = C.|last7 = Gates|first7 = J.M.|last8 = Golubev|first8 = P.|last9 = Gregorich|first9 = K.E.|last10 = Gross|first10 = C.J.|last11 = Herzberg|first11 = R.-D.|last12 = Heßberger|first12 = F.P.|last13 = Khuyagbaatar|first13 = J.|last14 = Kratz|first14 = J.V.|last15 = Rykaczewski|first15 = K.|last16 = Sarmiento|first16 = L.G.|last17 = Schädel|first17 = M.|last18 = Yakushev|first18 = A.|last19 = Åberg|first19 = S.|last20 = Ackermann|first20 = D.|last21 = Block|first21 = M.|last22 = Brand|first22 = H.|last23 = Carlsson|first23 = B.G.|last24 = Cox|first24 = D.|last25 = Derkx|first25 = X.|last26 = Dobaczewski|first26 = J.|last27 = Eberhardt|first27 = K.|last28 = Even|first28 = J.|last29 = Gerl|first29 = J.|last30 = Jäger|first30 = E.|display-authors = 3|bibcode = 2016NuPhA.953..117F| s2cid=55598355 }}{{cite journal |last1=Kaji |first1=Daiya |last2=Morita |first2=Kosuke |first3=Kouji |last3=Morimoto |first4=Hiromitsu |last4=Haba |first5=Masato |last5=Asai |first6=Kunihiro |last6=Fujita |first7=Zaiguo |last7=Gan |first8=Hans |last8=Geissel |first9=Hiroo |last9=Hasebe |first10=Sigurd |last10=Hofmann |first11=MingHui |last11=Huang |first12=Yukiko |last12=Komori |first13=Long |last13=Ma |first14=Joachim |last14=Maurer |first15=Masashi |last15=Murakami |first16=Mirei |last16=Takeyama |first17=Fuyuki |last17=Tokanai |first18=Taiki |last18=Tanaka |first19=Yasuo |last19=Wakabayashi |first20=Takayuki |last20=Yamaguchi |first21=Sayaka |last21=Yamaki |first22=Atsushi |last22=Yoshida |display-authors=3 |date=2017 |title=Study of the Reaction ⁴⁸Ca + ²⁴⁸Cm → ²⁹⁶Lv* at RIKEN-GARIS |journal=Journal of the Physical Society of Japan |volume=86 |issue=3 |pages=034201–1–7 |doi=10.7566/JPSJ.86.034201 |bibcode=2017JPSJ...86c4201K }}

| SF

| (various)

| 0+

|-id=Darmstadtium-281

| rowspan=2|²⁸¹DsNot directly synthesized, occurs in decay chain of ²⁸⁹Fl

| rowspan=2 style="text-align:right" | 110

| rowspan=2 style="text-align:right" | 171

| rowspan=2|281.16455(53)#

| rowspan=2|{{val|14|(3)|u=s}}

| SF (90%)

| (various)

| rowspan=2|

|-

| α (10%)

| ²⁷⁷Hs

|-id=Darmstadtium-281m

| style="text-indent:1em" | ^281mDsNot directly synthesized, occurs in decay chain of ²⁹³Lv, unconfirmed

| colspan="3" style="text-indent:2em" | 80(240)# keV

| {{val|0.25|1.18|0.11|u=s}}
[{{val|0.9|(7)|u=s}}]

| α

| ²⁷⁷Hs

|

|-id=Darmstadtium-282

| ²⁸²DsNot directly synthesized, occurs in decay chain of ²⁹⁰Fl, unconfirmed

|style="text-align:right" | 110

|style="text-align:right" | 172

|282.16617(32)#

| {{val|67|320|30|u=s}}
[{{val|4.2|(33)|u=min}}]

| α

| ²⁷⁸Hs

|0+

{{Isotopes table/footer}}

Superheavy elements such as darmstadtium are produced by bombarding lighter elements in particle accelerators that induce fusion reactions. Whereas most of the isotopes of darmstadtium can be synthesized directly this way, some heavier ones have only been observed as decay products of elements with higher atomic numbers.{{Cite journal |first1=Peter |last1=Armbruster |name-list-style=amp|first2=Gottfried|last2=Munzenberg |title=Creating superheavy elements |journal=Scientific American |volume=34 |pages=36–42 |year=1989}}

Depending on the energies involved, the former are separated into "hot" and "cold". In hot fusion reactions, very light, high-energy projectiles are accelerated toward very heavy targets (actinides), giving rise to compound nuclei at high excitation energy (~40–50 MeV) that may either fission or evaporate several (3 to 5) neutrons.{{cite journal |last1=Barber |first1=Robert C. |last2=Gäggeler |first2=Heinz W. |last3=Karol |first3=Paul J. |last4=Nakahara |first4=Hiromichi |last5=Vardaci |first5=Emanuele |last6=Vogt |first6=Erich |title=Discovery of the element with atomic number 112 (IUPAC Technical Report) |journal=Pure and Applied Chemistry |volume=81 |issue=7 |page=1331 |year=2009 |doi=10.1351/PAC-REP-08-03-05|doi-access=free }} In cold fusion reactions, the produced fused nuclei have a relatively low excitation energy (~10–20 MeV), which decreases the probability that these products will undergo fission reactions. As the fused nuclei cool to the ground state, they require emission of only one or two neutrons, and thus, allows for the generation of more neutron-rich products. The latter is a distinct concept from that of where nuclear fusion claimed to be achieved at room temperature conditions (see cold fusion).{{cite journal |last1=Fleischmann |first1=Martin |last2=Pons |first2=Stanley |year=1989 |title=Electrochemically induced nuclear fusion of deuterium |journal=Journal of Electroanalytical Chemistry and Interfacial Electrochemistry |volume=261 |issue=2 |pages=301–308 |publisher=Elsevier |doi=10.1016/0022-0728(89)80006-3 }}

The table below contains various combinations of targets and projectiles which could be used to form compound nuclei with Z = 110.

Before the first successful synthesis of darmstadtium in 1994 by the GSI team, scientists at GSI also tried to synthesize darmstadtium by bombarding lead-208 with nickel-64 in 1985. No darmstadtium atoms were identified. After an upgrade of their facilities, the team at GSI successfully detected 9 atoms of ²⁷¹Ds in two runs of their discovery experiment in 1994.{{cite journal|doi=10.1007/BF01291181|title=Production and decay of²⁶⁹110|year=1995|last1=Hofmann |first1=S.|journal=Zeitschrift für Physik A|volume=350|pages=277–280|last2=Ninov|first2=V.|last3=Heßberger|first3=F. P.|last4=Armbruster|first4=P.|last5=Folger|first5=H.|last6=Münzenberg|first6=G.|last7=Schött|first7=H. J.|last8=Popeko|first8=A. G.|last9=Yeremin|first9=A. V.|last10=Andreyev|first10=A. N.|last11=Saro|first11=S.|last12=Janik|first12=R.|last13=Leino|first13=M.|bibcode = 1995ZPhyA.350..277H|issue=4 |s2cid=125020220 }} This reaction was successfully repeated in 2000 by GSI (4 atoms), in 2000{{cite journal|doi=10.1103/PhysRevC.67.064609|title=Confirmation of production of element 110 by the ²⁰⁸Pb(⁶⁴Ni,n) reaction|year=2003|last1=Ginter |first1=T. N.|journal=Physical Review C|volume=67|page=064609 |last2=Gregorich|first2=K.|last3=Loveland|first3=W.|last4=Lee|first4=D.|last5=Kirbach|first5=U.|last6=Sudowe|first6=R.|last7=Folden|first7=C.|last8=Patin|first8=J.|last9=Seward|first9=N.|first10=P. |last10=Wilk|first11=P. |last11=Zielinski |first12=K. |last12=Aleklett|first13=R. |last13=Eichler|first14=H. |last14=Nitsche|first15=D. |last15=Hoffman |bibcode=2003PhRvC..67f4609G |issue=6 |url=https://zenodo.org/record/1233771}}{{cite web|url=http://repositories.cdlib.org/cgi/viewcontent.cgi?article=5446&context=lbnl|title=Confirmation of production of element 110 by the ²⁰⁸Pb(⁶⁴Ni,n) reaction|publisher=LBNL repositories |date=8 December 2002 |access-date=2008-03-02|last1=Ginter|first1=T. N.|last2=Gregorich |first2=K.|last3=Loveland|first3=W.|last4=Lee|first4=D.|last5=Kirbach|first5=U.|last6=Sudowe|first6=R.|last7=Folden|first7=C.|last8=Patin|first8=J.|last9=Seward|first9=N. }} (preprint) and 2004{{cite journal|doi=10.1103/PhysRevLett.93.212702 |title=Development of an Odd-Z-Projectile Reaction for Heavy Element Synthesis: ²⁰⁸Pb(⁶⁴Ni,n)²⁷¹Ds and ²⁰⁸Pb(⁶⁵Cu,n)²⁷²111|year=2004|last1=Folden|first1=C. M. |journal=Physical Review Letters|volume=93|page=212702|pmid=15601003|last2=Gregorich|first2=KE|last3=Düllmann|first3=ChE|last4=Mahmud|first4=H|last5=Pang|first5=GK|last6=Schwantes|first6=JM|last7=Sudowe|first7=R|last8=Zielinski|first8=PM|last9=Nitsche|first9=H|last10=Hoffman|first10=D.|issue=21|bibcode=2004PhRvL..93u2702F|url=http://repositories.cdlib.org/cgi/viewcontent.cgi?article=2704&context=lbnl}} by the Lawrence Berkeley National Laboratory (LBNL) (9 atoms in total) and in 2002 by RIKEN (14 atoms).{{cite journal|doi=10.1140/epja/i2003-10205-1|title=Production and decay of the isotope ²⁷¹Ds (Z = 110)|year=2004|last1=Morita |first1=K.|journal=The European Physical Journal A|volume=21 |last2=Morimoto|first2=K.|last3=Kaji|first3=D.|last4=Haba|first4=H.|last5=Ideguchi|first5=E.|last6=Kanungo|first6=R.|last7=Katori|first7=K.|last8=Koura|first8=H.|last9=Kudo|first9=H.|first10=T. |last10=Ohnishi|first11=A. |last11=Ozawa|first12=T. |last12=Suda|first13=K. |last13=Sueki|first14=I. |last14=Tanihata|first15=H. |last15=Xu|first16=A. V. |last16=Yeremin|first17=A. |last17=Yoneda|first18=A. |last18=Yoshida|first19=Y.-L. |last19=Zhao|first20=T. |last20=Zheng|pages=257–263|bibcode = 2004EPJA...21..257M|issue=2 | s2cid=123077512 }} The GSI team studied the analogous reaction with nickel-62 instead of nickel-64 in 1994 as part of their discovery experiment. Three atoms of ²⁶⁹Ds were detected. A fourth decay chain was measured but was subsequently retracted.{{cite news |url=https://www.nytimes.com/2002/10/15/science/at-lawrence-berkeley-physicists-say-a-colleague-took-them-for-a-ride.html?scp=2&sq=victor%20ninov&st=cse&pagewanted=1 |title=At Lawrence Berkeley, Physicists Say a Colleague Took Them for a Ride |author=George Johnson |newspaper=The New York Times |date=15 October 2002}}

In addition to the official discovery reactions, in October–November 2000, the team at GSI also studied the analogous reaction using a lead-207 target in order to synthesize the new isotope ²⁷⁰Ds. They succeeded in synthesising eight atoms of ²⁷⁰Ds, relating to a ground state isomer, ²⁷⁰Ds, and a high-spin metastable state, ^270mDs.{{cite journal|url=http://www.dnp.fmph.uniba.sk/etext/68/text/Hofmann_et_al_EPJ_A10_(2001)_5.pdf|title=The new isotope ²⁷⁰110 and its decay products ²⁶⁶Hs and ²⁶²Sg |last1=Hofmann |journal=Eur. Phys. J. A |volume=10 |issue=1 |pages=5–10 |year=2001 |doi=10.1007/s100500170137 |last2=Heßberger |first2=F. P. |last3=Ackermann |first3=D. |last4=Antalic |first4=S. |last5=Cagarda |first5=P. |last6=Ćwiok |first6=S. |last7=Kindler |first7=B. |last8=Kojouharova |first8=J. |last9=Lommel |first9=B. |first10=R. |last10=Mann |first11=G. |last11=Münzenberg |first12=A. G. |last12=Popeko |first13=S. |last13=Saro |first14=H. J. |last14=Schött |first15=A. V. |last15=Yeremin |bibcode = 2001EPJA...10....5H |s2cid=124240926 }}

In 1986, a team at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, studied the reaction:

:{{su|p=209|b=83|a=r}}Bi + {{su|p=59|b=27}}Co → {{su|p=267|b=110}}Ds + {{su|p=1|b=0}}n

They were unable to detect any darmstadtium atoms. In 1995, the team at LBNL reported that they had succeeded in detecting a single atom of ²⁶⁷Ds using this reaction. However, several decays were not measured and further research is required to confirm this discovery.{{cite journal|doi=10.1103/PhysRevC.51.R2293|pmid=9970386|title=Evidence for the possible synthesis of element 110 produced by the ⁵⁹Co+²⁰⁹Bi reaction|year=1995|last1=Ghiorso |first1=A. |journal=Physical Review C|volume=51|pages=R2293–R2297|last2=Lee|first2=D.|last3=Somerville|first3=L.|last4=Loveland|first4=W.|last5=Nitschke|first5=J.|last6=Ghiorso|first6=W.|last7=Seaborg|first7=G.|last8=Wilmarth|first8=P.|last9=Leres|first9=R.|first10=A. |last10=Wydler|first11=M. |last11=Nurmia|first12=K. |last12=Gregorich|first13=K. |last13=Czerwinski|first14=R. |last14=Gaylord|first15=T. |last15=Hamilton|first16=N. J. |last16=Hannink|first17=D. C. |last17=Hoffman|first18=C. |last18=Jarzynski|first19=C. |last19=Kacher|first20=B. |last20=Kadkhodayan|first21=S. |last21=Kreek|first22=M. |last22=Lane|first23=A. |last23=Lyon|first24=M. A. |last24=McMahan|first25=M. |last25=Neu|first26=T. |last26=Sikkeland|first27=W. J. |last27=Swiatecki|first28=A. |last28=Türler|first29=J. T. |last29=Walton|first30=S. |last30=Yashita |display-authors=3 |bibcode = 1995PhRvC..51.2293G|issue=5 }}

In the late 1980s, the GSI team attempted to synthesize element 110 by bombarding a target consisting of various uranium isotopes—²³³U, ²³⁵U, and ²³⁸U—with accelerated argon-40 ions. No atoms were detected;{{cite book |last=Hofmann |first=Sigurd |date=2002 |title=On Beyond Uranium |publisher=Taylor & Francis |page=[https://archive.org/details/onbeyonduraniumj0000hofm/page/150 150] |isbn=0-415-28496-1 |url=https://archive.org/details/onbeyonduraniumj0000hofm/page/150 }} a limiting cross section of 21 pb was reported.

In September 1994, the team at Dubna detected a single atom of ²⁷³Ds by bombarding a plutonium-244 target with accelerated sulfur-34 ions.{{cite journal|doi=10.1103/PhysRevC.54.620 |pmid = 9971385|title=α decay of ²⁷³110: Shell closure at N=162|year=1996|last1=Lazarev |first1=Yu. A.|journal=Physical Review C|volume=54|pages=620–625|last2=Lobanov|first2=Yu.|last3=Oganessian|first3=Yu.|last4=Utyonkov|first4=V.|last5=Abdullin|first5=F.|last6=Polyakov|first6=A.|last7=Rigol|first7=J.|last8=Shirokovsky|first8=I.|last9=Tsyganov|first9=Yu.|first10=S. |last10=Iliev|first11=V. G. |last11=Subbotin|first12=A. M. |last12=Sukhov|first13=G. V. |last13=Buklanov|first14=B. N. |last14=Gikal|first15=V. B. |last15=Kutner|first16=A. N. |last16=Mezentsev|first17=K. |last17=Subotic|first18=J. F. |last18=Wild|first19=R. W. |last19=Lougheed|first20=K. J. |last20=Moody |display-authors=3 |bibcode = 1996PhRvC..54..620L|issue=2 }}

Experiments were done in 2004 at the Flerov Laboratory of Nuclear Reactions (FLNR) in Dubna studying the fission characteristics of the compound nucleus ²⁸⁰Ds, produced in the reaction:

:{{su|p=232|b=90|a=r}}Th + {{su|p=48|b=20}}Ca → {{su|p=280|b=110}}Ds* → fission

The result revealed how compound nuclei such as this fission predominantly by expelling magic and doubly magic nuclei such as ¹³²Sn (Z = 50, N = 82). No darmstadtium atoms were obtained.[http://www1.jinr.ru/Reports/Reports_eng_arh.html Flerov lab annual report 2004] A compound nucleus is a loose combination of nucleons that have not arranged themselves into nuclear shells yet. It has no internal structure and is held together only by the collision forces between the target and projectile nuclei. It is estimated that it requires around 10⁻¹⁴ s for the nucleons to arrange themselves into nuclear shells, at which point the compound nucleus becomes a nuclide, and this number is used by IUPAC as the minimum half-life a claimed isotope must have in order to be recognized as being discovered.{{cite book|last=Emsley|first=John|title=Nature's Building Blocks: An A–Z Guide to the Elements|edition=New|year=2011|publisher=Oxford University Press|location=New York, NY|isbn=978-0-19-960563-7|page=590}}

The ²³²Th+⁴⁸Ca reaction was attempted again at the FLNR in 2022; it was predicted that the ⁴⁸Ca-induced reaction leading to element 110 would have a lower yield than those leading to lighter or heavier elements. Seven atoms of ²⁷⁶Ds were reported, with lifetimes ranging between {{val|9.3|u=us}} and {{val|983.1|u=us}}; four decayed by spontaneous fission and three decayed via a two-alpha sequence to ²⁷²Hs and the spontaneously fissioning ²⁶⁸Sg. The maximum reported cross section for the production of ²⁷⁶Ds was about 0.7 pb and a sensitivity limit an order of magnitude lower was reached. This reported cross section is lower than that of all reactions using ⁴⁸Ca as a projectile, with the exception of ²⁴⁹Cf + ⁴⁸Ca, and it further supports the existence of magic numbers at Z = 108, N = 162 and Z = 114, N = 184. In 2023, the JINR team repeated this reaction at a higher beam energy and also found ²⁷⁵Ds. They intend to further study the reaction to search for ²⁷⁴Ds.{{cite news |title=New darmstadtium isotope discovered at Superheavy Element Factory |url=http://www.jinr.ru/posts/new-darmstadtium-isotope-discovered-at-superheavy-element-factory/ |publisher=Joint Institute for Nuclear Research |date=27 February 2023 |access-date=29 March 2023}} The FLNR also successfully synthesised ²⁷³Ds in the ²³⁸U+⁴⁰Ar reaction.{{cite journal |last1=Oganessian |first1=Yuri |display-authors=etal |date=6 May 2024 |title=Synthesis and decay properties of isotopes of element 110: ²⁷³Ds and ²⁷⁵Ds |url= |journal=Physical Review C |volume=109 |issue=5 |pages=054307 |doi=10.1103/PhysRevC.109.054307 |access-date=}}

Darmstadtium has been observed as a decay product of copernicium. Copernicium currently has seven known isotopes, five of which have been shown to alpha decay into darmstadtium, with mass numbers 273, 277, and 279–281. To date, all of these bar ²⁷³Ds have only been produced by decay of copernicium. Parent copernicium nuclei can be themselves decay products of flerovium or livermorium. Darmstadtium may also have been produced in the electron capture decay of roentgenium nuclei which are themselves daughters of nihonium and moscovium.{{cite web|url=http://www.nndc.bnl.gov/chart/reCenter.jsp?z=110&n=171|title=Interactive Chart of Nuclides|publisher=Brookhaven National Laboratory|last=Sonzogni|first=Alejandro|location=National Nuclear Data Center|access-date=2008-06-06|archive-date=2017-07-14|archive-url=https://web.archive.org/web/20170714135726/http://www.nndc.bnl.gov/chart/reCenter.jsp?z=110&n=171|url-status=dead}} For example, in 2004, the Dubna team (JINR) identified darmstadtium-281 as a product in the decay of livermorium via an alpha decay sequence:

:{{nuclide|livermorium|293}} → {{nuclide|flerovium|289}} + {{nuclide|helium|4}}

:{{nuclide|flerovium|289}} → {{nuclide|copernicium|285}} + {{nuclide|helium|4}}

:{{nuclide|copernicium|285}} → {{nuclide|darmstadtium|281}} + {{nuclide|helium|4}}

;²⁸⁰Ds

The first synthesis of element 114 resulted in two atoms assigned to ²⁸⁸Fl, decaying to the ²⁸⁰Ds, which underwent spontaneous fission. The assignment was later changed to ²⁸⁹Fl and the darmstadtium isotope to ²⁸¹Ds. Hence, ²⁸⁰Ds remained unknown until 2016, when it was populated by the hitherto unknown alpha decay of ²⁸⁴Cn (previously, that nucleus was only known to undergo spontaneous fission). The discovery of ²⁸⁰Ds in this decay chain was confirmed in 2021; it undergoes spontaneous fission with a half-life of 360 μs.

;²⁷⁷Ds

In the claimed synthesis of ²⁹³Og in 1999, the isotope ²⁷⁷Ds was identified as decaying by 10.18 MeV alpha emission with a half-life of 3.0 ms. This claim was retracted in 2001. This isotope was finally created in 2010 and its decay data supported the fabrication of previous data.see Oganesson

;^273mDs

In the synthesis of ²⁷⁷Cn in 1996 by GSI (see copernicium), one decay chain proceeded via ²⁷³Ds, which decayed by emission of a 9.73 MeV alpha particle with a lifetime of 170 ms. This would have been assigned to an isomeric level. This data could not be confirmed and thus this isotope is currently unknown or unconfirmed.{{Citation needed|date=November 2024}}

;²⁷²Ds

In the first attempt to synthesize darmstadtium, a 10 ms SF activity was assigned to ²⁷²Ds in the reaction ²³²Th(⁴⁴Ca,4n).{{cite journal |title=Reactions of ⁴⁰Ar with ²³³U, ²³⁵U, and ²³⁸U at the barrier |first1=U. W. |last1=Scherer |first2=W |last2=Brüchle |first3=M. |last3=Brügger |first4=C. |last4=Frink |first5=H. |last5=Gäggeler |first6=G. |last6=Herrmann |first7=J. V. |last7=Kratz |first8=K. J. |last8=Moody |first9=M. |last9=Schädel |first10=K. |last10=Sümmerer |first11=N. |last11=Trautmann |first12=G. |last12=Wirth |journal=Zeitschrift für Physik A |volume=335 |pages=421–430 |year=1990 |issue=4 |doi=10.1007/BF01290190|bibcode=1990ZPhyA.335..421S |s2cid=101394312 }} Given current understanding regarding stability, this isotope has been retracted from the table of isotopes.

Image:270Ds decay scheme.png

;²⁸¹Ds

The production of ²⁸¹Ds by the decay of ²⁸⁹Fl or ²⁹³Lv has produced two very different decay modes. The most common and readily confirmed mode is spontaneous fission with a half-life of 11 s. A much rarer and as yet unconfirmed mode is alpha decay by emission of an alpha particle with energy 8.77 MeV with an observed half-life of around 3.7 min. This decay is associated with a unique decay pathway from the parent nuclides and must be assigned to an isomeric level. The half-life suggests that it must be assigned to an isomeric state but further research is required to confirm these reports. It was suggested in 2016 that this unknown activity might be due to ²⁸²Mt, the great-granddaughter of ²⁹⁰Fl via electron capture and two consecutive alpha decays.{{cite journal |last1=Hofmann |first1=S. |last2=Heinz |first2=S. |first3=R. |last3=Mann |first4=J. |last4=Maurer |first5=G. |last5=Münzenberg |first6=S. |last6=Antalic |first7=W. |last7=Barth |first8=H. G. |last8=Burkhard |first9=L. |last9=Dahl |first10=K. |last10=Eberhardt |first11=R. |last11=Grzywacz |first12=J. H. |last12=Hamilton |first13=R. A. |last13=Henderson |first14=J. M. |last14=Kenneally |first15=B. |last15=Kindler |first16=I. |last16=Kojouharov |first17=R. |last17=Lang |first18=B. |last18=Lommel |first19=K. |last19=Miernik |first20=D. |last20=Miller |first21=K. J. |last21=Moody |first22=K. |last22=Morita |first23=K. |last23=Nishio |first24=A. G. |last24=Popeko |first25=J. B. |last25=Roberto |first26=J. |last26=Runke |first27=K. P. |last27=Rykaczewski |first28=S. |last28=Saro |first29=C. |last29=Scheidenberger |first30=H. J. |last30=Schött |first31=D. A. |last31=Shaughnessy |first32=M. A. |last32=Stoyer |first33=P. |last33=Thörle-Popiesch |first34=K. |last34=Tinschert |first35=N. |last35=Trautmann |first36=J. |last36=Uusitalo |first37=A. V. |last37=Yeremin |display-authors=3 |date=2016 |title=Review of even element super-heavy nuclei and search for element 120 |journal=The European Physical Journal A |volume=2016 |issue=52 |pages=180 |doi=10.1140/epja/i2016-16180-4|bibcode=2016EPJA...52..180H |s2cid=254113387 |url=https://zenodo.org/record/897926 }}

;²⁷¹Ds

Decay data from the direct synthesis of ²⁷¹Ds clearly indicates the presence of two nuclear isomers. The first emits alpha particles with energies 10.74 and 10.69 MeV and has a half-life of 1.63 ms. The other only emits alpha particles with an energy of 10.71 MeV and has a half-life of 69 ms. The first has been assigned to the ground state and the latter to an isomeric level. It has been suggested that the closeness of the alpha decay energies indicates that the isomeric level may decay primarily by delayed isomeric transition to the ground state, resulting in an identical measured alpha energy and a combined half-life for the two processes.{{cite journal|doi=10.1088/0034-4885/61/6/002|year=1998|last=Hofmann |first=S|journal=Reports on Progress in Physics|volume=61|pages=639–689|bibcode = 1998RPPh...61..639H|title=New elements - approaching|issue=6 |s2cid=250756383 }}

;²⁷⁰Ds

The direct production of ²⁷⁰Ds has clearly identified two nuclear isomers. The ground state decays by alpha emission into the ground state of ²⁶⁶Hs by emitting an alpha particle with energy 11.03 MeV and has a half-life of 0.10 ms. The metastable state decays by alpha emission, emitting alpha particles with energies of 12.15, 11.15, and 10.95 MeV, and has a half-life of 6 ms. When the metastable state emits an alpha particle of energy 12.15 MeV, it decays into the ground state of ²⁶⁶Hs, indicating that it has 1.12 MeV of excess energy.

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

Experiments have been performed in 2004 at the Flerov Laboratory of Nuclear Reactions in Dubna studying the fission characteristics of the compound nucleus ²⁸⁰Ds. The nuclear reaction used is ²³²Th+⁴⁸Ca. The result revealed how nuclei such as this fission predominantly by expelling closed shell nuclei such as ¹³²Sn (Z = 50, N = 82).see [http://www1.jinr.ru/Reports/Reports_eng_arh.html Flerov lab annual report 2004]

Theoretical calculation in a quantum tunneling model reproduces the experimental alpha decay half-live data.{{cite journal|journal=Phys. Rev. C|volume=73|issue=1|page=014612|year=2006|title=α decay half-lives of new superheavy elements|author=P. Roy Chowdhury |author2=C. Samanta |author3=D. N. Basu|doi=10.1103/PhysRevC.73.014612|arxiv = nucl-th/0507054 |bibcode = 2006PhRvC..73a4612C |s2cid=118739116 }}{{cite journal| journal=Nucl. Phys. A|volume=789|issue=1–4|pages=142–154|year=2007| title=Predictions of alpha decay half lives of heavy and superheavy elements|author=C. Samanta |author2=P. Roy Chowdhury |author3=D. N. Basu|doi=10.1016/j.nuclphysa.2007.04.001|arxiv = nucl-th/0703086 |bibcode = 2007NuPhA.789..142S |s2cid=7496348 }} It also predicts that the isotope ²⁹⁴Ds would have alpha decay half-life of the order of 311 years.{{cite journal|journal=Phys. Rev. C|volume=77|page=044603|year=2008|title=Search for long lived heaviest nuclei beyond the valley of stability|author=P. Roy Chowdhury |first2=C. |last2=Samanta |first3=D. N. |last3=Basu|doi=10.1103/PhysRevC.77.044603|bibcode = 2008PhRvC..77d4603C|issue=4|arxiv = 0802.3837 |s2cid=119207807 }}{{cite journal|journal=Atomic Data and Nuclear Data Tables|year=2008|title=Nuclear half-lives for α -radioactivity of elements with 100 ≤ Z ≤ 130 |first1=P. Roy |last1=Chowdhury |author2=C. Samanta| author3=D. N. Basu |doi=10.1016/j.adt.2008.01.003|volume=94|pages=781–806|bibcode = 2008ADNDT..94..781C|issue=6 |arxiv = 0802.4161 |s2cid=96718440 }}

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

{{Reflist}}

{{Navbox element isotopes}}

Category:Darmstadtium

Darmstadtium