Isotopes of darmstadtium

Last updated
Isotopes of darmstadtium  (110Ds)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
279Ds synth 0.2 s α 10% 275Hs
SF 90%–
281Dssynth14 sSF94%–
α6% 277Hs

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 (with many gaps) and 2 or 3 known isomers. The longest-lived isotope is 281Ds with a half-life of 14 seconds.

Contents

List of isotopes

Nuclide
[n 1] 		Z N Isotopic mass (Da)
[n 2] [n 3] 		Half-life
Decay
mode
[n 4] 		Daughter
isotope
Spin and
parity
[n 5] [n 6]
Excitation energy
267Ds [n 7] 110157267.14377(15)#10(8) µs
[2.8+13.0
−1.3 μs]		 α  ?263Hs ?3/2+#
269Ds110159269.14475(3)230(110) µs
[170+160
−60 μs]		α265Hs3/2+#
270Ds [2] 110160270.14458(5)200+70
−40 μs		α266Hs0+
270mDs1040 keV3.9+1.3
−0.8 ms		α (70%) [3] 266Hs10-#
IT (30%)270Ds
271Ds110161271.14595(10)#210(170) msα267Hs11/2−#
271mDs29(29) keV1.3(5) msα267Hs9/2+#
273Ds110163273.14856(14)#240(100) µsα269Hs13/2−#
275Ds [4] 110165275.15203(45)#62 µsα271Hs
276Ds [5] 110166276.15303(59)#150+100
−40 μs		 SF (57%)(various)0+
α (43%)272Hs
277Ds [n 8] 110167277.15591(41)#3.5+2.1
−0.9 ms [6] 		α273Hs11/2+#
279Ds [n 9] 110169279.16010(64)#186+21
−17 ms [7] 		SF (87%) [7] (various)
α (13%)275Hs
280Ds [n 10] 110170280.16131(89)#360+172
−16 μs [8] [9] [10] 		SF(various)0+
281Ds [n 11] 110171281.16451(59)#14(3) sSF (90%)(various)3/2+#
α (10%)277Hs
This table header & footer:
  1. ↑ mDs – Excited nuclear isomer.
  2. ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ↑ Modes of decay:
    SF: Spontaneous fission
  5. ↑ ( ) spin value – Indicates spin with weak assignment arguments.
  6. ↑ # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  7. ↑ Unconfirmed isotope
  8. ↑ Not directly synthesized, occurs in decay chain of 285Fl
  9. ↑ Not directly synthesized, occurs as decay product of 283Cn
  10. ↑ Not directly synthesized, occurs in decay chain of 288Fl
  11. ↑ Not directly synthesized, occurs in decay chain of 289Fl

Isotopes and nuclear properties

Nucleosynthesis

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. [11]

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. [12] 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. [11] The latter is a distinct concept from that of where nuclear fusion claimed to be achieved at room temperature conditions (see cold fusion). [13]

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

TargetProjectileCNAttempt result
208Pb62Ni270DsSuccessful reaction
207Pb64Ni271DsSuccessful reaction
208Pb64Ni272DsSuccessful reaction
209Bi59Co268DsSuccessful reaction
226Ra50Ti276DsReaction yet to be attempted
232Th44Ca276DsFailure to date
232Th48Ca280DsSuccessful reaction
233U40Ar273DsFailure to date [14]
235U40Ar275DsFailure to date [14]
238U40Ar278DsSuccessful reaction
244Pu34S278DsSuccessful reaction
244Pu36S280DsReaction yet to be attempted
248Cm30Si278DsReaction yet to be attempted
250Cm30Si280DsReaction yet to be attempted

Cold fusion

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. [15] This reaction was successfully repeated in 2000 by GSI (4 atoms), in 2000 [16] [17] and 2004 [18] by the Lawrence Berkeley National Laboratory (LBNL) (9 atoms in total) and in 2002 by RIKEN (14 atoms). [19] 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. [15] A fourth decay chain was measured but was subsequently retracted. [20]

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. [21]

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

209
83Bi + 59
27Co → 267
110Ds + 1
0n

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. [22]

Hot fusion

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; [23] a limiting cross section of 21 pb was reported. [14]

In September 1994, the team at Dubna detected a single atom of 273Ds by bombarding a plutonium-244 target with accelerated sulfur-34 ions. [24]

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:

232
90Th + 48
20Ca → 280
110Ds* → 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. [25] 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. [26] [27]

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 9.3 μs and 983.1 μs; four decayed by spontaneous fission and three decayed via a two-alpha sequence to 272Hs and the spontaneously fissioning 268Sg. [5] 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. [5] In 2023, the JINR team repeated this reaction at a higher beam energy and also found 275Ds. [4] They intend to further study the reaction to search for 274Ds. [4] The FLNR also successfully synthesised 273Ds in the 238U+40Ar reaction. [28]

As decay product

List of darmstadtium isotopes observed by decay
Evaporation residueObserved darmstadtium isotope
277Cn273Ds [29]
285Fl, 281Cn277Ds [30]
291Lv, 287Fl, 283Cn279Ds [31]
288Fl, 284Cn280Ds
288Mc, 284Nh, 280Rg ?280Ds ?
293Lv, 289Fl, 285Cn281Ds [32]

Darmstadtium has been observed as a decay product of copernicium. Copernicium currently has seven known isotopes, four 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. [27] For example, in 2004, the Dubna team (JINR) identified darmstadtium-281 as a product in the decay of livermorium via an alpha decay sequence: [32]

293
116Lv
 → 289
114Fl
 + 4
2He
289
114Fl
 → 285
112Cn
 + 4
2He
285
112Cn
 → 281
110Ds
 + 4
2He

Retracted isotopes

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. [8]

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. [33]

273mDs

In the synthesis of 277Cn in 1996 by GSI (see copernicium), one decay chain proceeded via273Ds, 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.

272Ds

In the first attempt to synthesize darmstadtium, a 10 ms SF activity was assigned to 272Ds in the reaction 232Th(44Ca,4n). [14] Given current understanding regarding stability, this isotope has been retracted from the table of isotopes.

Nuclear isomerism

The current partial decay level scheme for Ds proposed following the work of Hofmann et al. in 2000 at GSI 270Ds decay scheme.png
The current partial decay level scheme for Ds proposed following the work of Hofmann et al. in 2000 at GSI
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. [32] 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. [34]

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. [35]

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. [21]

Chemical yields of isotopes

Cold fusion

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.

ProjectileTargetCN1n2n3n
62Ni208Pb270Ds3.5 pb
64Ni208Pb272Ds15 pb, 9.9 MeV

Fission of compound nuclei with Z = 110

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). [36]

Theoretical calculations

Decay characteristics

Theoretical calculation in a quantum tunneling model reproduces the experimental alpha decay half-live data. [37] [38] It also predicts that the isotope 294Ds would have alpha decay half-life of the order of 311 years. [39] [40]

Evaporation residue cross sections

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
208Pb64Ni272Ds1n (271Ds)10 pbDNS [41]
232Th48Ca280Ds4n (276Ds)0.2 pbDNS [42]
230Th48Ca278Ds4n (274Ds)1 pbDNS [42]
238U40Ar278Ds4n (274Ds)2 pbDNS [42]
244Pu36S280Ds4n (276Ds)0.61 pbDNS [43]
248Cm30Si278Ds4n (274Ds)65.32 pbDNS [43]
250Cm30Si280Ds4n (276Ds)3.54 pbDNS [43]

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">Rutherfordium</span> Chemical element, symbol Rf and atomic number 104

Rutherfordium is a synthetic chemical element; it has symbol Rf and atomic number 104. It is named after physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be made in a particle accelerator. It is radioactive; the most stable known isotope, 267Rf, has a half-life of about 48 minutes.

<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.

<span class="mw-page-title-main">Roentgenium</span> Chemical element, symbol Rg and atomic number 111

Roentgenium is a synthetic chemical element; it has symbol Rg and atomic number 111. It is extremely radioactive and can only be created in a laboratory. The most stable known isotope, roentgenium-282, has a half-life of 120 seconds, although the unconfirmed roentgenium-286 may have a longer half-life of about 10.7 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. It is named after the physicist Wilhelm Röntgen, who discovered X-rays. Only a few roentgenium atoms have ever been synthesized, and they have no practical application.

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">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.

<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.

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).

Rutherfordium (104Rf) is a synthetic element and thus has no stable isotopes. A standard atomic weight cannot be given. The first isotope to be synthesized was either 259Rf in 1966 or 257Rf in 1969. There are 16 known radioisotopes from 253Rf to 270Rf and several isomers. The longest-lived isotope is 267Rf with a half-life of 48 minutes, and the longest-lived isomer is 263mRf with a half-life of 8 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 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.

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.

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.

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.

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.

References

  1. ↑ 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.
  2. ↑ Ackermann, Dieter (23–27 January 2012). "270Ds and its decay products – K-isomers, α-sf competition and masses". Proceedings of 50th International Winter Meeting on Nuclear Physics — PoS(Bormio2012). Vol. 160. p. 030. doi: 10.22323/1.160.0030 . Retrieved 1 July 2023.
  3. ↑ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (1 March 2021). "The NUBASE2020 evaluation of nuclear physics properties *". Chinese Physics C, High Energy Physics and Nuclear Physics. 45 (3): 030001. Bibcode:2021ChPhC..45c0001K. doi: 10.1088/1674-1137/abddae . ISSN   1674-1137. OSTI   1774641. S2CID   233794940.
  4. 1 2 3 "New darmstadtium isotope discovered at Superheavy Element Factory". Joint Institute for Nuclear Research. 27 February 2023. Retrieved 29 March 2023.
  5. 1 2 3 Oganessian, Yu. Ts.; Utyonkov, V. K.; Shumeiko, M. V.; et al. (2023). "New isotope 276Ds and its decay products 272Hs and 268Sg from the 232Th + 48Ca reaction". Physical Review C. 108 (24611): 024611. Bibcode:2023PhRvC.108b4611O. doi:10.1103/PhysRevC.108.024611. S2CID   261170871.
  6. ↑ Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu. Ts.; et al. (30 January 2018). "Neutron-deficient superheavy nuclei obtained in the 240Pu+48Ca reaction". Physical Review C. 97 (14320): 014320. Bibcode:2018PhRvC..97a4320U. doi: 10.1103/PhysRevC.97.014320 .
  7. 1 2 Oganessian, Yu. Ts.; Utyonkov, V. K.; Ibadullayev, D.; et al. (2022). "Investigation of 48Ca-induced reactions with 242Pu and 238U targets at the JINR Superheavy Element Factory". Physical Review C. 106 (24612): 024612. Bibcode:2022PhRvC.106b4612O. doi:10.1103/PhysRevC.106.024612. OSTI   1883808. S2CID   251759318.
  8. 1 2 Såmark-Roth, A.; Cox, D. M.; Rudolph, D.; et al. (2021). "Spectroscopy along Flerovium Decay Chains: Discovery of 280Ds and an Excited State in 282Cn". Physical Review Letters. 126 (3): 032503. Bibcode:2021PhRvL.126c2503S. doi: 10.1103/PhysRevLett.126.032503 . hdl: 10486/705608 . PMID   33543956.
  9. ↑ Forsberg, U.; Rudolph, D.; Andersson, L.-L.; et al. (2016). "Recoil-α-fission and recoil-α–α-fission events observed in the reaction 48Ca + 243Am". Nuclear Physics A. 953: 117–138. arXiv: 1502.03030 . Bibcode:2016NuPhA.953..117F. doi:10.1016/j.nuclphysa.2016.04.025. S2CID   55598355.
  10. ↑ Kaji, Daiya; Morita, Kosuke; Morimoto, Kouji; et al. (2017). "Study of the Reaction 48Ca + 248Cm → 296Lv* at RIKEN-GARIS". Journal of the Physical Society of Japan. 86 (3): 034201–1–7. Bibcode:2017JPSJ...86c4201K. doi:10.7566/JPSJ.86.034201.
  11. 1 2 Armbruster, Peter & Munzenberg, Gottfried (1989). "Creating superheavy elements". Scientific American. 34: 36–42.
  12. ↑ Barber, Robert C.; Gäggeler, Heinz W.; Karol, Paul J.; Nakahara, Hiromichi; Vardaci, Emanuele; Vogt, Erich (2009). "Discovery of the element with atomic number 112 (IUPAC Technical Report)". Pure and Applied Chemistry. 81 (7): 1331. doi: 10.1351/PAC-REP-08-03-05 .
  13. ↑ Fleischmann, Martin; Pons, Stanley (1989). "Electrochemically induced nuclear fusion of deuterium". Journal of Electroanalytical Chemistry and Interfacial Electrochemistry. 261 (2). Elsevier: 301–308. doi:10.1016/0022-0728(89)80006-3.
  14. 1 2 3 4 Scherer, U. W.; Brüchle, W; Brügger, M.; Frink, C.; Gäggeler, H.; Herrmann, G.; Kratz, J. V.; Moody, K. J.; Schädel, M.; Sümmerer, K.; Trautmann, N.; Wirth, G. (1990). "Reactions of 40Ar with 233U, 235U, and 238U at the barrier". Zeitschrift für Physik A. 335 (4): 421–430. Bibcode:1990ZPhyA.335..421S. doi:10.1007/BF01290190. S2CID   101394312.
  15. 1 2 Hofmann, S.; Ninov, V.; Heßberger, F. P.; Armbruster, P.; Folger, H.; Münzenberg, G.; Schött, H. J.; Popeko, A. G.; Yeremin, A. V.; Andreyev, A. N.; Saro, S.; Janik, R.; Leino, M. (1995). "Production and decay of269110". Zeitschrift für Physik A. 350 (4): 277–280. Bibcode:1995ZPhyA.350..277H. doi:10.1007/BF01291181. S2CID   125020220.
  16. ↑ Ginter, T. N.; Gregorich, K.; Loveland, W.; Lee, D.; Kirbach, U.; Sudowe, R.; Folden, C.; Patin, J.; Seward, N.; Wilk, P.; Zielinski, P.; Aleklett, K.; Eichler, R.; Nitsche, H.; Hoffman, D. (2003). "Confirmation of production of element 110 by the 208Pb(64Ni,n) reaction". Physical Review C. 67 (6): 064609. Bibcode:2003PhRvC..67f4609G. doi:10.1103/PhysRevC.67.064609.
  17. ↑ Ginter, T. N.; Gregorich, K.; Loveland, W.; Lee, D.; Kirbach, U.; Sudowe, R.; Folden, C.; Patin, J.; Seward, N. (8 December 2002). "Confirmation of production of element 110 by the 208Pb(64Ni,n) reaction". LBNL repositories. Retrieved 2008-03-02. (preprint)
  18. ↑ Folden, C. M.; Gregorich, KE; Düllmann, ChE; Mahmud, H; Pang, GK; Schwantes, JM; Sudowe, R; Zielinski, PM; Nitsche, H; Hoffman, D. (2004). "Development of an Odd-Z-Projectile Reaction for Heavy Element Synthesis: 208Pb(64Ni,n)271Ds and 208Pb(65Cu,n)272111". Physical Review Letters. 93 (21): 212702. Bibcode:2004PhRvL..93u2702F. doi:10.1103/PhysRevLett.93.212702. PMID   15601003.
  19. ↑ Morita, K.; Morimoto, K.; Kaji, D.; Haba, H.; Ideguchi, E.; Kanungo, R.; Katori, K.; Koura, H.; Kudo, H.; Ohnishi, T.; Ozawa, A.; Suda, T.; Sueki, K.; Tanihata, I.; Xu, H.; Yeremin, A. V.; Yoneda, A.; Yoshida, A.; Zhao, Y.-L.; Zheng, T. (2004). "Production and decay of the isotope 271Ds (Z = 110)". The European Physical Journal A. 21 (2): 257–263. Bibcode:2004EPJA...21..257M. doi:10.1140/epja/i2003-10205-1. S2CID   123077512.
  20. ↑ George Johnson (15 October 2002). "At Lawrence Berkeley, Physicists Say a Colleague Took Them for a Ride". The New York Times.
  21. 1 2 3 Hofmann; Heßberger, F. P.; Ackermann, D.; Antalic, S.; Cagarda, P.; Ćwiok, S.; Kindler, B.; Kojouharova, J.; Lommel, B.; Mann, R.; Münzenberg, G.; Popeko, A. G.; Saro, S.; Schött, H. J.; Yeremin, A. V. (2001). "The new isotope 270110 and its decay products 266Hs and 262Sg" (PDF). Eur. Phys. J. A. 10 (1): 5–10. Bibcode:2001EPJA...10....5H. doi:10.1007/s100500170137. S2CID   124240926.
  22. ↑ Ghiorso, A.; Lee, D.; Somerville, L.; et al. (1995). "Evidence for the possible synthesis of element 110 produced by the 59Co+209Bi reaction". Physical Review C. 51 (5): R2293–R2297. Bibcode:1995PhRvC..51.2293G. doi:10.1103/PhysRevC.51.R2293. PMID   9970386.
  23. ↑ Hofmann, Sigurd (2002). On Beyond Uranium. Taylor & Francis. p.  150. ISBN   0-415-28496-1.
  24. ↑ Lazarev, Yu. A.; Lobanov, Yu.; Oganessian, Yu.; et al. (1996). "α decay of 273110: Shell closure at N=162". Physical Review C. 54 (2): 620–625. Bibcode:1996PhRvC..54..620L. doi:10.1103/PhysRevC.54.620. PMID   9971385.
  25. ↑ Flerov lab annual report 2004
  26. ↑ Emsley, John (2011). Nature's Building Blocks: An A–Z Guide to the Elements (New ed.). New York, NY: Oxford University Press. p. 590. ISBN   978-0-19-960563-7.
  27. 1 2 Sonzogni, Alejandro. "Interactive Chart of Nuclides". National Nuclear Data Center: Brookhaven National Laboratory. Archived from the original on 2017-07-14. Retrieved 2008-06-06.
  28. ↑ Oganessian, Yuri; et al. (6 May 2024). "Synthesis and decay properties of isotopes of element 110: 273Ds and 275Ds". Physical Review C. 109 (5): 054307. doi:10.1103/PhysRevC.109.054307.
  29. ↑ Hofmann, S.; Ninov, V.; Heßberger, F. P.; Armbruster, P.; Folger, H.; Münzenberg, G.; Schött, H. J.; Popeko, A. G.; Yeremin, A. V.; Saro, S.; Janik, R.; Leino, M. (1996). "The new element 112". Zeitschrift für Physik A . 354 (1): 229–230. Bibcode:1996ZPhyA.354..229H. doi:10.1007/BF02769517. S2CID   119975957.
  30. ↑ Public Affairs Department (26 October 2010). "Six New Isotopes of the Superheavy Elements Discovered: Moving Closer to Understanding the Island of Stability". Berkeley Lab . Retrieved 2011-04-25.
  31. ↑ Yeremin, A. V.; et al. (1999). "Synthesis of nuclei of the superheavy element 114 in reactions induced by 48Ca". Nature . 400 (6741): 242–245. Bibcode:1999Natur.400..242O. doi:10.1038/22281. S2CID   4399615.
  32. 1 2 3 Oganessian, Y. T.; Utyonkov, V.; Lobanov, Y.; Abdullin, F.; Polyakov, A.; Shirokovsky, I.; Tsyganov, Y.; Gulbekian, G.; Bogomolov, S.; Gikal, B.; et al. (2004). "Measurements of cross sections for the fusion-evaporation reactions 244Pu(48Ca,xn)292−x114 and 245Cm(48Ca,xn)293−x116". Physical Review C. 69 (5): 054607. Bibcode:2004PhRvC..69e4607O. doi: 10.1103/PhysRevC.69.054607 .
  33. ↑ see Oganesson
  34. ↑ 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   254113387.
  35. ↑ Hofmann, S (1998). "New elements - approaching". Reports on Progress in Physics. 61 (6): 639–689. Bibcode:1998RPPh...61..639H. doi:10.1088/0034-4885/61/6/002. S2CID   250756383.
  36. ↑ see Flerov lab annual report 2004
  37. ↑ P. Roy Chowdhury; C. Samanta; D. N. Basu (2006). "α decay half-lives of new superheavy elements". Phys. Rev. C. 73 (1): 014612. arXiv: nucl-th/0507054 . Bibcode:2006PhRvC..73a4612C. doi:10.1103/PhysRevC.73.014612. S2CID   118739116.
  38. ↑ 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.
  39. ↑ P. Roy Chowdhury; Samanta, C.; Basu, D. N. (2008). "Search for long lived heaviest nuclei beyond the valley of stability". Phys. Rev. C. 77 (4): 044603. arXiv: 0802.3837 . Bibcode:2008PhRvC..77d4603C. doi:10.1103/PhysRevC.77.044603. S2CID   119207807.
  40. ↑ Chowdhury, P. Roy; 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.
  41. ↑ Feng, Zhao-Qing; Jin, Gen-Ming; Li, Jun-Qing; Scheid, Werner (2007). "Formation of superheavy nuclei in cold fusion reactions". Physical Review C. 76 (4): 044606. arXiv: 0707.2588 . Bibcode:2007PhRvC..76d4606F. doi:10.1103/PhysRevC.76.044606. S2CID   711489.
  42. 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.
  43. 1 2 3 Feng, Z.; Jin, G.; Li, J. (2009). "Production of new superheavy Z=108-114 nuclei with 238U, 244Pu and 248,250Cm targets". Physical Review C . 80: 057601. arXiv: 0912.4069 . doi:10.1103/PhysRevC.80.057601. S2CID   118733755.
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