Isotopes of rutherfordium

Last updated
Isotopes of rutherfordium  (104Rf)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
261Rf synth 2.1 s SF 82%–
α 18% 257No
263Rfsynth15 min [2] SF<100%?–
α~30%? 259No
265Rfsynth1.1 min [3] SF–
267Rfsynth48 min [4] SF–

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 (3 of which, 266Rf, 268Rf, and 270Rf, are unconfirmed) 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.

Contents

List of isotopes

Nuclide
[n 1] 		Z N Isotopic mass (Da)
[n 2] [n 3] 		Half-life
[n 4] 		Decay
mode
[n 5] 		Daughter
isotope
Spin and
parity
[n 6] [n 4]
Excitation energy [n 4]
253Rf [5] 104149253.10044(44)#9.9(1.2) ms SF (83%)(various)(1/2+)
α (17%)249No
253m1Rf200(150)# keV52.8(4.4) µsSF(various)(7/2+)
253m2Rf>1020 keV0.66+0.40
−0.18 ms		 IT 253m1Rf
254Rf [6] 104150254.10005(30)#23.2(1.1) µsSF (100%)(various)0+
α (<1.5%) [7] 250No
254m1Rf>1350 keV4.7(1.1) µsIT254Rf(8-)
254m2Rf247(73) µsIT254m1Rf(16+)
255Rf [8] 104151255.10127(12)#1.69(3) sSF (50.9%)(various)(9/2−)
α (49.1%)251No
β+ (<6%)255Lr
255m1Rf150 keV50(17) µsIT255Rf(5/2+)
255m2Rf1103 keV29+7
−5 μs		IT255Rf(19/2+)
255m3Rf1303 keV49+13
−10 μs		IT255Rf(25/2+)
256Rf [9] 104152256.101152(19)6.67(9) msSF (99.68%)(various)0+
α (0.32%) [10] 252No
256m1Rf~1120 keV25(2) µsIT256Rf
256m2Rf~1400 keV17(2) µsIT256m1Rf
256m3Rf>2200 keV27(5) µsIT256m2Rf
257Rf104153257.102917(12) [11] 6.2+1.2
−1.0 s [12] 		α (89.3%)253No(1/2+)
β+ (9.4%) [13] 257mLr
SF (1.3%) [14] (various)
257m1Rf [12] 74 keV4.37(5) sα (80.54%)253No(11/2-)
IT (14.2%)257Rf
β+ (4.86%)257Lr
SF (0.4%)(various)
257m2Rf [15] ~1125 keV134.9(77) µsIT257m1Rf(21/2, 23/2)
258Rf [1] 104154258.10343(3)12.5(5) msSF (95.1%)(various)0+
α (4.9%)254No
258m1Rf1200(300)# keV2.4+2.4
−0.8 ms [16] 		IT258Rf
258m2Rf1500(500)# keV15(10) µsIT258m1Rf
259Rf [1] 104155259.10560(8)#2.63(26) sα (85%)255No3/2+#
β+ (15%)259Lr
260Rf104156260.10644(22)#21(1) msSF(various)0+
α (<20%) [17] 256No
261Rf104157261.10877(5)75(7) s [18] α257No9/2+#
β+ (<14%) [19] 261Lr
SF (<11%) [20] (various)
261mRf70(100)# keV1.9(4) s [21] SF (73%)(various)3/2+#
α (27%)257No
262Rf104158262.10993(24)#210+128
−58 ms [22] 		SF(various)0+
262mRf600(400)# keV47(5) msSF(various)high
263Rf104159263.1125(2)#11(3) minSF (77%)(various)3/2+#
α (23%) [23] 259No
263mRf [n 7] 8+40
−4 s [24] 		SF(various)
265Rf [n 8] 104161265.11668(39)#1.1+0.8
−0.3 min [3] 		SF(various)
266Rf [n 9] [n 10] 104162266.11817(50)#23 s# [25] [26] SF(various)0+
267Rf [n 11] 104163267.12179(62)#48+23
−12 min [4] 		SF(various)13/2−#
268Rf [n 9] [n 12] 104164268.12397(77)#1.4 s# [26] [27] SF(various)0+
270Rf [28] [n 9] [n 13] 10416620 ms# [26] [29] SF(various)0+
This table header & footer:
  1. ↑ mRf – 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. 1 2 3 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ↑ Modes of decay:
    SF: Spontaneous fission
  6. ↑ ( ) spin value – Indicates spin with weak assignment arguments.
  7. ↑ Not directly synthesized, occurs in decay chain of 271Hs
  8. ↑ Not directly synthesized, occurs in decay chain of 285Fl
  9. 1 2 3 Discovery of this isotope is unconfirmed
  10. ↑ Not directly synthesized, occurs in decay chain of 282Nh
  11. ↑ Not directly synthesized, occurs in decay chain of 287Fl
  12. ↑ Not directly synthesized, occurs in decay chain of 288Mc
  13. ↑ Not directly synthesized, occurs in decay chain of 294Ts

Nucleosynthesis

Super-heavy elements such as rutherfordium are produced by bombarding lighter elements in particle accelerators that induces fusion reactions. Whereas most of the isotopes of rutherfordium can be synthesized directly this way, some heavier ones have only been observed as decay products of elements with higher atomic numbers. [30]

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. [30] 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. [31] The latter is a distinct concept from that of where nuclear fusion claimed to be achieved at room temperature conditions (see cold fusion). [32]

Hot fusion studies

The synthesis of rutherfordium was first attempted in 1964 by the team at Dubna using the hot fusion reaction of neon-22 projectiles with plutonium-242 targets:

242
94Pu
 + 22
10Ne
 → 264−x
104Rf
 + 3 or 5
n
 .

The first study produced evidence for a spontaneous fission with a 0.3 second half-life and another one at 8 seconds. While the former observation was eventually retracted, the latter eventually became associated with the 259Rf isotope. [33] In 1966, the Soviet team repeated the experiment using a chemical study of volatile chloride products. They identified a volatile chloride with eka-hafnium properties that decayed fast through spontaneous fission. This gave strong evidence for the formation of RfCl4, and although a half-life was not accurately measured, later evidence suggested that the product was most likely 259Rf. The team repeated the experiment several times over the next few years, and in 1971, they revised the spontaneous fission half-life for the isotope at 4.5 seconds. [33]

In 1969, researchers at the University of California led by Albert Ghiorso, tried to confirm the original results reported at Dubna. In a reaction of curium-248 with oxygen-16, they were unable to confirm the result of the Soviet team, but managed to observe the spontaneous fission of 260Rf with a very short half-life of 10–30 ms:

248
96Cm
 + 16
8O
 → 260
104Rf
 + 4
n
 .

In 1970, the American team also studied the same reaction with oxygen-18 and identified 261Rf with a half-life of 65 seconds (later refined to 75 seconds). [34] [35] Later experiments at the Lawrence Berkeley National Laboratory in California also revealed the formation of a short-lived isomer of 262Rf (which undergoes spontaneous fission with a half-life of 47 ms), [36] and spontaneous fission activities with long lifetimes tentatively assigned to 263Rf. [37]

Diagram of the experimental set-up used in the discovery of isotopes Rf and Rf Rutherfordium experimental setup.jpeg
Diagram of the experimental set-up used in the discovery of isotopes Rf and Rf

The reaction of californium-249 with carbon-13 was also investigated by the Ghiorso team, which indicated the formation of the short-lived 258Rf (which undergoes spontaneous fission in 11 ms): [38]

249
98Cf
 + 13
6C
 → 258
104Rf
 + 4
n
 .

In trying to confirm these results by using carbon-12 instead, they also observed the first alpha decays from 257Rf. [38]

The reaction of berkelium-249 with nitrogen-14 was first studied in Dubna in 1977, and in 1985, researchers there confirmed the formation of the 260Rf isotope which quickly undergoes spontaneous fission in 28 ms: [33]

249
97Bk
 + 14
7N
 → 260
104Rf
 + 3
n
 .

In 1996 the isotope 262Rf was observed in LBNL from the fusion of plutonium-244 with neon-22:

244
94Pu
 + 22
10Ne
 → 266−x
104Rf
 + 4 or 5
n
 .

The team determined a half-life of 2.1 seconds, in contrast to earlier reports of 47 ms and suggested that the two half-lives might be due to different isomeric states of 262Rf. [39] Studies on the same reaction by a team at Dubna, lead to the observation in 2000 of alpha decays from 261Rf and spontaneous fissions of 261mRf. [40]

The hot fusion reaction using a uranium target was first reported at Dubna in 2000:

238
92U
 + 26
12Mg
 → 264−x
104Rf
 + x
n
 (x = 3, 4, 5, 6).

They observed decays from 260Rf and 259Rf, and later for 259Rf. In 2006, as part of their program on the study of uranium targets in hot fusion reactions, the team at LBNL also observed 261Rf. [40] [41] [42]

Cold fusion studies

The first cold fusion experiments involving element 104 were done in 1974 at Dubna, by using light titanium-50 nuclei aimed at lead-208 isotope targets:

208
82Pb
 + 50
22Ti
 → 258−x
104Rf
 + x
n
 (x = 1, 2, or 3).

The measurement of a spontaneous fission activity was assigned to 256Rf, [43] while later studies done at the Gesellschaft für Schwerionenforschung Institute (GSI), also measured decay properties for the isotopes 257Rf, and 255Rf. [44] [45]

In 1974 researchers at Dubna investigated the reaction of lead-207 with titanium-50 to produce the isotope 255Rf. [46] In a 1994 study at GSI using the lead-206 isotope, 255Rf as well as 254Rf were detected. 253Rf was similarly detected that year when lead-204 was used instead. [45]

Decay studies

Most isotopes with an atomic mass below 262 have also observed as decay products of elements with a higher atomic number, allowing for refinement of their previously measured properties. Heavier isotopes of rutherfordium have only been observed as decay products. For example, a few alpha decay events terminating in 267Rf were observed in the decay chain of darmstadtium-279 since 2004:

279
110Ds
 → 275
108Hs
 +
α
 → 271
106Sg
 +
α
 → 267
104Rf
 +
α
 .

This further underwent spontaneous fission with a half-life of about 1.3 h. [47] [48] [49]

Investigations on the synthesis of the dubnium-263 isotope in 1999 at the University of Bern revealed events consistent with electron capture to form 263Rf. A rutherfordium fraction was separated, and several spontaneous fission events with long half-lives of about 15 minutes were observed, as well as alpha decays with half-lives of about 10 minutes. [37] Reports on the decay chain of flerovium-285 in 2010 showed five sequential alpha decays that terminate in 265Rf, which further undergoes spontaneous fission with a half-life of 152 seconds. [50]

Some experimental evidence was obtained in 2004 for an even heavier isotope, 268Rf, in the decay chain of an isotope of moscovium:

288
115Mc
 → 284
113Nh
 +
α
 → 280
111Rg
 +
α
 → 276
109Mt
 +
α
 → 272
107Bh
 +
α
 → 268
105Db
 +
α
  ? → 268
104Rf
 +
ν
e .

However, the last step in this chain was uncertain. After observing the five alpha decay events that generate dubnium-268, spontaneous fission events were observed with a long half-life. It is unclear whether these events were due to direct spontaneous fission of 268Db, or 268Db produced electron capture events with long half-lives to generate 268Rf. If the latter is produced and decays with a short half-life, the two possibilities cannot be distinguished. [51] Given that the electron capture of 268Db cannot be detected, these spontaneous fission events may be due to 268Rf, in which case the half-life of this isotope cannot be extracted. [27] [52] A similar mechanism is proposed for the formation of the even heavier isotope 270Rf as a short-lived daughter of 270Db (in the decay chain of 294Ts, first synthesized in 2010) which then undergoes spontaneous fission: [28]

294
117Ts
 → 290
115Mc
 +
α
 → 286
113Nh
 +
α
 → 282
111Rg
 +
α
 → 278
109Mt
 +
α
 → 274
107Bh
 +
α
 → 270
105Db
 +
α
  ? → 270
104Rf
 +
ν
e .

According to a 2007 report on the synthesis of nihonium, the isotope 282Nh was twice observed to undergo a similar decay to form 266Db. In one case this underwent spontaneous fission with a half-life of 22 minutes. Given that the electron capture of 266Db cannot be detected, these spontaneous fission events may be due to 266Rf, in which case the half-life of this isotope cannot be extracted. In the other case, no spontaneous fission event was observed; it could have been missed, or 266Db might have undergone two more alpha decays to long-lived 258Md, with a half-life (51.5 d) longer than the total time of the experiment. [25] [53]

Nuclear isomerism

Currently suggested decay level scheme for Rf from the studies reported in 2007 by Hessberger et al. at GSI 257Rf decay scheme 2006.png
Currently suggested decay level scheme for Rf from the studies reported in 2007 by Hessberger et al. at GSI

Several early studies on the synthesis of 263Rf have indicated that this nuclide decays primarily by spontaneous fission with a half-life of 10–20 minutes. More recently, a study of hassium isotopes allowed the synthesis of atoms of 263Rf decaying with a shorter half-life of 8 seconds. These two different decay modes must be associated with two isomeric states, but specific assignments are difficult due to the low number of observed events. [37]

During research on the synthesis of rutherfordium isotopes utilizing the 244Pu(22Ne,5n)261Rf reaction, the product was found to undergo exclusive 8.28 MeV alpha decay with a half-life of 78 seconds. Later studies at GSI on the synthesis of copernicium and hassium isotopes produced conflicting data, as 261Rf produced in the decay chain was found to undergo 8.52 MeV alpha decay with a half-life of 4 seconds. Later results indicated a predominant fission branch. These contradictions led to some doubt on the discovery of copernicium. The first isomer is currently denoted 261aRf (or simply 261Rf) whilst the second is denoted 261bRf (or 261mRf). However, it is thought that the first nucleus belongs to a high-spin ground state and the latter to a low-spin metastable state. [55] The discovery and confirmation of 261bRf provided proof for the discovery of copernicium in 1996. [56]

A detailed spectroscopic study of the production of 257Rf nuclei using the reaction 208Pb(50Ti,n)257Rf allowed the identification of an isomeric level in 257Rf. The work confirmed that 257gRf has a complex spectrum with 15 alpha lines. A level structure diagram was calculated for both isomers. [57] Similar isomers were reported for 256Rf also. [58]

Chemical yields of isotopes

Cold fusion

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

ProjectileTargetCN1n2n3n
50Ti208Pb258Rf38.0 nb, 17.0 MeV12.3 nb, 21.5 MeV660 pb, 29.0 MeV
50Ti207Pb257Rf4.8 nb
50Ti206Pb256Rf800 pb, 21.5 MeV2.4 nb, 21.5 MeV
50Ti204Pb254Rf190 pb, 15.6 MeV
48Ti208Pb256Rf380 pb, 17.0 MeV

Hot fusion

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

ProjectileTargetCN3n4n5n
26Mg238U264Rf240 pb1.1 nb
22Ne244Pu266Rf+4.0 nb
18O248Cm266Rf+13.0 nb

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References

  1. 1 2 3 Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ↑ Sonzogni, Alejandro. "Interactive Chart of Nuclides". National Nuclear Data Center: Brookhaven National Laboratory. Retrieved 2008-06-06.
  3. 1 2 Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu. Ts.; Rykaczewski, K. P.; Abdullin, F. Sh.; Dimitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu. S.; Voinov, A. A.; Subbotin, V. G.; Sukhov, A. M.; Karpov, A. V.; Popeko, A. G.; Sabel'nikov, A. V.; Svirikhin, A. I.; Vostokin, G. K.; Hamilton, J. H.; Kovrinzhykh, N. D.; Schlattauer, L.; Stoyer, M. A.; Gan, Z.; Huang, W. X.; Ma, L. (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.
  4. 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. S2CID   251759318.
  5. ↑ Lopez-Martens, A.; Hauschild, K.; Svirikhin, A. I.; Asfari, Z.; Chelnokov, M. L.; Chepigin, V. I.; Dorvaux, O.; Forge, M.; Gall, B.; Isaev, A. V.; Izosimov, I. N.; Kessaci, K.; Kuznetsova, A. A.; Malyshev, O. N.; Mukhin, R. S.; Popeko, A. G.; Popov, Yu. A.; Sailaubekov, B.; Sokol, E. A.; Tezekbayeva, M. S.; Yeremin, A. V. (22 February 2022). "Fission properties of Rf 253 and the stability of neutron-deficient Rf isotopes". Physical Review C. 105 (2). arXiv: 2202.11802 . doi:10.1103/PhysRevC.105.L021306. ISSN   2469-9985. S2CID   247072308 . Retrieved 16 June 2023.
  6. ↑ David, H. M.; Chen, J.; Seweryniak, D.; Kondev, F. G.; Gates, J. M.; Gregorich, K. E.; Ahmad, I.; Albers, M.; Alcorta, M.; Back, B. B.; Baartman, B.; Bertone, P. F.; Bernstein, L. A.; Campbell, C. M.; Carpenter, M. P.; Chiara, C. J.; Clark, R. M.; Cromaz, M.; Doherty, D. T.; Dracoulis, G. D.; Esker, N. E.; Fallon, P.; Gothe, O. R.; Greene, J. P.; Greenlees, P. T.; Hartley, D. J.; Hauschild, K.; Hoffman, C. R.; Hota, S. S.; Janssens, R. V. F.; Khoo, T. L.; Konki, J.; Kwarsick, J. T.; Lauritsen, T.; Macchiavelli, A. O.; Mudder, P. R.; Nair, C.; Qiu, Y.; Rissanen, J.; Rogers, A. M.; Ruotsalainen, P.; Savard, G.; Stolze, S.; Wiens, A.; Zhu, S. (24 September 2015). "Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in Rf 254". Physical Review Letters. 115 (13): 132502. doi:10.1103/PhysRevLett.115.132502. hdl: 1885/152426 . ISSN   0031-9007. PMID   26451549. S2CID   22923276 . Retrieved 16 June 2023.
  7. ↑ Heßberger, F. P.; Hofmann, S.; Ninov, V.; Armbruster, P.; Folger, H.; Münzenberg, G.; Schött, H. J.; Popeko, A. G.; Yeremin, A. V.; Andreyev, A. N.; Saro, S. (1 December 1997). "Spontaneous fission and alpha-decay properties of neutron deficient isotopes 257−253104 and 258106" (PDF). Zeitschrift für Physik A. 359 (4): 415–425. Bibcode:1997ZPhyA.359..415A. doi:10.1007/s002180050422. ISSN   1431-5831. S2CID   121551261 . Retrieved 16 June 2023.
  8. ↑ Chakma, R.; Lopez-Martens, A.; Hauschild, K.; Yeremin, A. V.; Malyshev, O. N.; Popeko, A. G.; Popov, Yu. A.; Svirikhin, A. I.; Chepigin, V. I.; Sokol, E. A.; Isaev, A. V.; Kuznetsova, A. A.; Chelnokov, M. L.; Tezekbayeva, M. S.; Izosimov, I. N.; Dorvaux, O.; Gall, B.; Asfari, Z. (31 January 2023). "Investigation of isomeric states in Rf 255". Physical Review C. 107 (1): 014326. doi:10.1103/PhysRevC.107.014326. ISSN   2469-9985. S2CID   256489616 . Retrieved 16 June 2023.
  9. ↑ Jeppesen, H. B.; Dragojević, I.; Clark, R. M.; Gregorich, K. E.; Ali, M. N.; Allmond, J. M.; Beausang, C. W.; Bleuel, D. L.; Cromaz, M.; Deleplanque, M. A.; Ellison, P. A.; Fallon, P.; Garcia, M. A.; Gates, J. M.; Greene, J. P.; Gros, S.; Lee, I. Y.; Liu, H. L.; Macchiavelli, A. O.; Nelson, S. L.; Nitsche, H.; Pavan, J. R.; Stavsetra, L.; Stephens, F. S.; Wiedeking, M.; Wyss, R.; Xu, F. R. (6 March 2009). "Multi-quasiparticle states in Rf 256". Physical Review C. 79 (3): 031303. Bibcode:2009PhRvC..79c1303J. doi:10.1103/PhysRevC.79.031303. ISSN   0556-2813 . Retrieved 16 June 2023.
  10. ↑ Heßberger, F. P.; Hofmann, S.; Ninov, V.; Armbruster, P.; Folger, H.; Münzenberg, G.; Schött, H. J.; Popeko, A. G.; Yeremin, A. V.; Andreyev, A. N.; Saro, S. (1 December 1997). "Spontaneous fission and alpha-decay properties of neutron deficient isotopes 257−253104 and 258106" (PDF). Zeitschrift für Physik A. 359 (4): 415–425. Bibcode:1997ZPhyA.359..415A. doi:10.1007/s002180050422. ISSN   1431-5831. S2CID   121551261 . Retrieved 16 June 2023.
  11. ↑ AME 2020 atomic mass evaluation
  12. 1 2 Hauschild, K.; Lopez-Martens, A.; Chakma, R.; Chelnokov, M. L.; Chepigin, V. I.; Isaev, A. V.; Izosimov, I. N.; Katrasev, D. E.; Kuznetsova, A. A.; Malyshev, O. N.; Popeko, A. G.; Popov, Yu. A.; Sokol, E. A.; Svirikhin, A. I.; Tezekbayeva, M. S.; Yeremin, A. V.; Asfari, Z.; Dorvaux, O.; Gall, B. J. P.; Kessaci, K.; Ackermann, D.; Piot, J.; Mosat, P.; Andel, B. (18 January 2022). "Alpha-decay spectroscopy of $$^{257}$$Rf". The European Physical Journal A. 58 (1): 6. doi:10.1140/epja/s10050-021-00657-8. ISSN   1434-601X. S2CID   233394478 . Retrieved 17 June 2023.
  13. ↑ Heßberger, F. P.; Antalic, S.; Mistry, A. K.; Ackermann, D.; Andel, B.; Block, M.; Kalaninova, Z.; Kindler, B.; Kojouharov, I.; Laatiaoui, M.; Lommel, B.; Piot, J.; Vostinar, M. (20 July 2016). "Alpha- and EC-decay measurements of 257Rf". The European Physical Journal A. 52 (7): 192. doi:10.1140/epja/i2016-16192-0. ISSN   1434-601X. S2CID   254108438 . Retrieved 17 June 2023.
  14. ↑ Streicher, B.; Heßberger, F. P.; Antalic, S.; Hofmann, S.; Ackermann, D.; Heinz, S.; Kindler, B.; Khuyagbaatar, J.; Kojouharov, I.; Kuusiniemi, P.; Leino, M.; Lommel, B.; Mann, R.; Šáro, Š.; Sulignano, B.; Uusitalo, J.; Venhart, M. (1 September 2010). "Alpha-gamma decay studies of 261Sg and 257Rf" (PDF). The European Physical Journal A. 45 (3): 275–286. Bibcode:2010EPJA...45..275S. doi:10.1140/epja/i2010-11005-2. ISSN   1434-601X. S2CID   120939068 . Retrieved 17 June 2023.
  15. ↑ Berryman, J. S.; Clark, R. M.; Gregorich, K. E.; Allmond, J. M.; Bleuel, D. L.; Cromaz, M.; Dragojević, I.; Dvorak, J.; Ellison, P. A.; Fallon, P.; Garcia, M. A.; Gros, S.; Lee, I. Y.; Macchiavelli, A. O.; Nitsche, H.; Paschalis, S.; Petri, M.; Qian, J.; Stoyer, M. A.; Wiedeking, M. (29 June 2010). "Electromagnetic decays of excited states in Sg 261 ( Z = 106 ) and Rf 257 ( Z = 104 )". Physical Review C. 81 (6): 064325. doi:10.1103/PhysRevC.81.064325. ISSN   0556-2813 . Retrieved 17 June 2023.
  16. ↑ Heßberger, F. P.; Antalic, S.; Ackermann, D.; Andel, B.; Block, M.; Kalaninova, Z.; Kindler, B.; Kojouharov, I.; Laatiaoui, M.; Lommel, B.; Mistry, A. K.; Piot, J.; Vostinar, M. (11 November 2016). "Investigation of electron capture decay of 258Db and $\alpha$decay of 258Rf". The European Physical Journal A. 52 (11): 328. doi:10.1140/epja/i2016-16328-2. ISSN   1434-601X. S2CID   125302206 . Retrieved 18 June 2023.
  17. ↑ Lazarev, Yu. A.; Lobanov, Yu. V.; Oganessian, Yu. Ts.; Utyonkov, V. K.; Abdullin, F. Sh.; Polyakov, A. N.; Rigol, J.; Shirokovsky, I. V.; Tsyganov, Yu. S.; Iliev, S.; Subbotin, V. G.; Sukhov, A. M.; Buklanov, G. V.; Mezentsev, A. N.; Subotic, K.; Moody, K. J.; Stoyer, N. J.; Wild, J. F.; Lougheed, R. W. (13 November 2000). "Decay properties of 257 No , 261 Rf , and 262 Rf". Physical Review C. 62 (6): 064307. Bibcode:2000PhRvC..62f4307L. doi:10.1103/PhysRevC.62.064307. ISSN   0556-2813 . Retrieved 17 June 2023.
  18. ↑ Sylwester, E. R.; Adams, J. L.; Lane, M. R.; Shaughnessy, D. A.; Wilk, P. A.; Hoffman, D. C.; Gregorich, K. E.; Lee, D. M.; Laue, C. A.; McGrath, C. A.; Strellis, D. A.; Kadkhodayan, B.; Tuerler, A.; Kacher, C. D. (1 July 2000). "On-line gas chromatographic studies of Rf, Zr, and Hf bromides". Radiochimica Acta. 88 (12): 837–844. doi:10.1524/ract.2000.88.12.837. S2CID   201281991 . Retrieved 17 June 2023.
  19. ↑ Henderson, Roger. "Chemical and Nuclear Properties of Lawrencium (Element 103) and Hahnium (Element 105)" (PDF). University of California, Berkeley. Retrieved 17 June 2023.
  20. ↑ Kadkhodayen, B.; Tuerler, A.; Gregorich, K. E.; Baisden, P. A.; Czerwinski, K. R.; Eichler, B.; Gaeggeler, H. W.; Hamilton, T. M.; Jost, D. T.; Kacher, C. D.; Kovacs, A.; Kreek, S. A.; Lane, M. R.; Mohar, M. F.; Neu, M. P.; Stoyer, N. J.; Sylwester, E. R.; Lee, D. M.; Nurmia, M. J.; Seaborg, G. T.; Hoffman, D. C. (1 August 1996). "On-line gas chromatographic studies of chlorides of rutherfordium and homologs Zr and Hf". Radiochimica Acta. 72. Retrieved 17 June 2023.
  21. ↑ Haba, H.; Kaji, D.; Kikunaga, H.; Kudou, Y.; Morimoto, K.; Morita, K.; Ozeki, K.; Sumita, T.; Yoneda, A.; Kasamatsu, Y.; Komori, Y.; Ooe, K.; Shinohara, A. (2011). "Production and decay properties of the 1.9-s isomeric state in 261Rf". Physical Review C. 83 (3): 034602. Bibcode:2011PhRvC..83c4602H. doi:10.1103/physrevc.83.034602.
  22. ↑ Gorshkov; et al. "Measurements of 260-262Rf produced in 22Ne + 244Pu fusion reaction at TASCA" (PDF). GSI. Retrieved 16 June 2023.
  23. ↑ Kacher, Christian D. (30 October 1995). "Chemical and nuclear properties of Rutherfordium (Element 104)". Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). doi:10.2172/193914. OSTI   193914 . Retrieved 18 June 2023.{{cite journal}}: Cite journal requires |journal= (help)
  24. ↑ Dvorak, J.; Brüchle, W.; Chelnokov, M.; Düllmann, Ch. E.; Dvorakova, Z.; Eberhardt, K.; Jäger, E.; Krücken, R.; Kuznetsov, A.; Nagame, Y.; Nebel, F.; Nishio, K.; Perego, R.; Qin, Z.; Schädel, M.; Schausten, B.; Schimpf, E.; Schuber, R.; Semchenkov, A.; Thörle, P.; Türler, A.; Wegrzecki, M.; Wierczinski, B.; Yakushev, A.; Yeremin, A. (3 April 2008). "Observation of the 3 n Evaporation Channel in the Complete Hot-Fusion Reaction Mg 26 + Cm 248 Leading to the New Superheavy Nuclide Hs 271". Physical Review Letters. 100 (13): 132503. doi:10.1103/PhysRevLett.100.132503. ISSN   0031-9007. PMID   18517941 . Retrieved 16 June 2023.
  25. 1 2 Oganessian, Yu. Ts.; et al. (2007). "Synthesis of the isotope 282113 in the Np237+Ca48 fusion reaction". Physical Review C. 76 (1): 011601. Bibcode:2007PhRvC..76a1601O. doi:10.1103/PhysRevC.76.011601.
  26. 1 2 3 Oganessian, Yuri (8 February 2012). "Nuclei in the "Island of Stability" of Superheavy Elements". Journal of Physics: Conference Series. 337 (1): 012005. Bibcode:2012JPhCS.337a2005O. doi: 10.1088/1742-6596/337/1/012005 .
  27. 1 2 "CERN Document Server: Record#831577: Chemical Identification of Dubnium as a Decay Product of Element 115 Produced in the Reaction 48Ca + 243Am". Cdsweb.cern.ch. Retrieved 2010-09-19.
  28. 1 2 Stock, Reinhard (13 September 2013). Encyclopedia of Nuclear Physics and its Applications. John Wiley & Sons. ISBN   9783527649266 . Retrieved 8 April 2018– via Google Books.
  29. ↑ Fritz Peter Heßberger. "Exploration of Nuclear Structure and Decay of Heaviest Elements at GSI - SHIP". agenda.infn.it. Retrieved 2016-09-10.
  30. 1 2 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 .
  31. ↑ Armbruster, Peter & Munzenberg, Gottfried (1989). "Creating superheavy elements". Scientific American. 34: 36–42.
  32. ↑ Fleischmann, Martin; Pons, Stanley (1989). "Electrochemically induced nuclear fusion of deuterium". Journal of Electroanalytical Chemistry and Interfacial Electrochemistry. 261 (2): 301–308. doi:10.1016/0022-0728(89)80006-3.
  33. 1 2 3 "Discovery of the transneptunium elements", IUPAC/IUPAP Technical Report, Pure Appl. Chem., Vol. 65, No. 8, pp. 1757-1814,1993. Retrieved on 2008-03-04
  34. ↑ Ghiorso, A.; Nurmia, M.; Eskola, K.; Eskola, P. (1970). "261Rf; new isotope of element 104". Physics Letters B. 32 (2): 95–98. Bibcode:1970PhLB...32...95G. doi:10.1016/0370-2693(70)90595-2.
  35. ↑ Sylwester; Gregorich, K. E.; et al. (2000). "On-line gas chromatographic studies of Rf, Zr, and Hf bromides". Radiochimica Acta. 88 (12_2000): 837. doi:10.1524/ract.2000.88.12.837. S2CID   201281991.
  36. ↑ Somerville, L. P.; Nurmia, M. J.; Nitschke, J. M.; Ghiorso, A.; Hulet, E. K.; Lougheed, R. W. (1985). "Spontaneous fission of rutherfordium isotopes". Physical Review C. 31 (5): 1801–1815. Bibcode:1985PhRvC..31.1801S. doi:10.1103/PhysRevC.31.1801. PMID   9952719.
  37. 1 2 3 Kratz; Nähler, A.; et al. (2003). "An EC-branch in the decay of 27-s263Db: Evidence for the new isotope263Rf" (PDF). Radiochim. Acta. 91 (1–2003): 59–62. doi:10.1524/ract.91.1.59.19010. S2CID   96560109. Archived from the original (PDF) on 2009-02-25.
  38. 1 2 Ghiorso; et al. (1969). "Positive Identification of Two Alpha-Particle-Emitting Isotopes of Element 104". Phys. Rev. Lett. 22 (24): 1317–1320. Bibcode:1969PhRvL..22.1317G. doi: 10.1103/physrevlett.22.1317 .
  39. ↑ Lane; Gregorich, K.; et al. (1996). "Spontaneous fission properties of 104262Rf". Physical Review C. 53 (6): 2893–2899. Bibcode:1996PhRvC..53.2893L. doi:10.1103/PhysRevC.53.2893. PMID   9971276.
  40. 1 2 Lazarev, Yu; et al. (2000). "Decay properties of 257No, 261Rf, and 262Rf". Physical Review C. 62 (6): 64307. Bibcode:2000PhRvC..62f4307L. doi:10.1103/PhysRevC.62.064307.
  41. ↑ Gregorich, K. E.; et al. (2005). "Systematic Study of Heavy Element Production in Compound Nucleus Reactions with 238U Targets" (PDF). LBNL annual report. Retrieved 2008-02-29.
  42. ↑ Gates; Garcia, M. A.; et al. (2008). "Synthesis of rutherfordium isotopes in the 238U(26Mg,xn)264−xRf reaction and study of their decay properties". Physical Review C. 77 (3): 34603. Bibcode:2008PhRvC..77c4603G. doi:10.1103/PhysRevC.77.034603. S2CID   42983895.
  43. ↑ Oganessian, Yu. Ts.; Demin, A. G.; Il'inov, A. S.; Tret'yakova, S. P.; Pleve, A. A.; Penionzhkevich, Yu. É.; Ivanov, M. P.; Tret'yakov, Yu. P. (1975). "Experiments on the synthesis of neutron-deficient kurchatovium isotopes in reactions induced by 50Ti Ions". Nuclear Physics A. 38 (6): 492–501. Bibcode:1975NuPhA.239..157O. doi:10.1016/0375-9474(75)91140-9.
  44. ↑ Heßberger, F. P.; Münzenberg, G.; et al. (1985). "Study of evaporation residues produced in reactions of 207,208Pb with 50Ti". Zeitschrift für Physik A. 321 (2): 317–327. Bibcode:1985ZPhyA.321..317H. doi:10.1007/BF01493453. S2CID   118720320.
  45. 1 2 Heßberger, F. P.; Hofmann, S.; Ninov, V.; Armbruster, P.; Folger, H.; Münzenberg, G.; Schött, H. J.; Popeko, A. K.; Yeremin, A. V.; Andreyev, A. N.; Saro, S. (1997). "Spontaneous fission and alpha-decay properties of neutron deficient isotopes 257−253104 and 258106". Zeitschrift für Physik A. 359 (4): 415–425. Bibcode:1997ZPhyA.359..415A. doi:10.1007/s002180050422. S2CID   121551261.
  46. ↑ Heßberger, F. P.; Hofmann, S.; Ackermann, D.; Ninov, V.; Leino, M.; Münzenberg, G.; Saro, S.; Lavrentev, A.; Popeko, A. G.; Yeremin, A. V.; Stodel, Ch. (2001). "Decay properties of neutron-deficient isotopes 256,257Db, 255Rf, 252,253Lr"]". European Physical Journal A. 12 (1): 57–67. Bibcode:2001EPJA...12...57H. doi:10.1007/s100500170039. S2CID   117896888.
  47. ↑ Hofmann, S. (2009). "Superheavy Elements". The Euroschool Lectures on Physics with Exotic Beams, Vol. III Lecture Notes in Physics. Vol. 764. Springer. pp. 203–252. doi:10.1007/978-3-540-85839-3_6. ISBN   978-3-540-85838-6.
  48. ↑ Oganessian, Yu. Ts.; Utyonkov, V.; Lobanov, Yu.; Abdullin, F.; Polyakov, A.; Shirokovsky, I.; Tsyganov, Yu.; Gulbekian, G.; Bogomolov, S.; Gikal, B. N.; et al. (2004). "Measurements of cross sections and decay properties of the isotopes of elements 112, 114, and 116 produced in the fusion reactions 233,238U, 242Pu, and 248Cm+48Ca" (PDF). Physical Review C. 70 (6): 064609. Bibcode:2004PhRvC..70f4609O. doi:10.1103/PhysRevC.70.064609.
  49. ↑ Oganessian, Yuri (2007). "Heaviest nuclei from 48Ca-induced reactions". Journal of Physics G: Nuclear and Particle Physics. 34 (4): R165–R242. Bibcode:2007JPhG...34R.165O. doi:10.1088/0954-3899/34/4/R01.
  50. ↑ Ellison, P.; Gregorich, K.; Berryman, J.; Bleuel, D.; Clark, R.; Dragojević, I.; Dvorak, J.; Fallon, P.; Fineman-Sotomayor, C.; et al. (2010). "New Superheavy Element Isotopes: ". Physical Review Letters. 105 (18): 182701. Bibcode:2010PhRvL.105r2701E. doi:10.1103/PhysRevLett.105.182701. PMID   21231101.
  51. ↑ Oganessian, Yury Ts; Dmitriev, Sergey N (2009). "Superheavy elements in D I Mendeleev's Periodic Table". Russian Chemical Reviews. 78 (12): 1077–1087. Bibcode:2009RuCRv..78.1077O. doi:10.1070/RC2009v078n12ABEH004096. S2CID   250848732.
  52. ↑ Krebs, Robert E. (2006). The history and use of our earth's chemical elements: a reference guide. Greenwood Publishing Group. p. 344. ISBN   978-0-313-33438-2 . Retrieved 2010-09-19.
  53. ↑ Hofmann, S. (2009). "Superheavy Elements". The Euroschool Lectures on Physics with Exotic Beams, Vol. III Lecture Notes in Physics. Vol. 764. Springer. p. 229. doi:10.1007/978-3-540-85839-3_6. ISBN   978-3-540-85838-6.
  54. ↑ Streicher, B.; et al. (2010). "Alpha-gamma decay studies of 261Sg and 257Rf". The European Physical Journal A. 45 (3): 275–286. Bibcode:2010EPJA...45..275S. doi:10.1140/epja/i2010-11005-2. S2CID   120939068.
  55. ↑ Dressler, R.; Türler, A. Evidence for isomeric states in 261Rf (PDF) (Report). PSI Annual Report 2001. Archived from the original (PDF) on 2011-07-07. Retrieved 2008-01-29.
  56. ↑ Barber, R. C.; Gaeggeler, H. W.; Karol, P. J.; Nakahara, H.; Vardaci, E; Vogt, E. (2009). "Discovery of the element with atomic number 112" (IUPAC Technical Report). Pure Appl. Chem. 81 (7): 1331. doi:10.1351/PAC-REP-08-03-05. S2CID   95703833.
  57. ↑ Qian, J.; et al. (2009). "Spectroscopy of Rf257". Physical Review C. 79 (6): 064319. Bibcode:2009PhRvC..79f4319Q. doi:10.1103/PhysRevC.79.064319.
  58. ↑ Jeppesen; Dragojević, I.; et al. (2009). "Multi-quasiparticle states in256Rf". Physical Review C. 79 (3): 031303(R). Bibcode:2009PhRvC..79c1303J. doi:10.1103/PhysRevC.79.031303.
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