Deleng sumberé Rutherfordium

{{Elementbox_header | number=104 | symbol=Rf | name=rutherfordium | left=[[lawrencium]] | right=[[dubnium]] | above=[[hafnium|Hf]] | below=(Upq) | color1=#ffc0c0 | color2=black }}
{{Elementbox_series | [[logam transisi]] }}
{{Elementbox_groupperiodblock | group=4 | period=7 | block=d }}
{{Elementbox_atomicmass_gpm | [267] }}
{{Elementbox_econfig | &#91;[[radon|Rn]]&#93; 5f<sup>14</sup> 6d<sup>2</sup> 7s<sup>2</sup> }}
{{Elementbox_epershell | 2, 8, 18, 32, 32, 10, 2 }}
{{Elementbox_section_physicalprop | color1=#ffc0c0 | color2=black }}
{{Elementbox_phase | presumably a [[padhet]] }}
{{Elementbox_density_gpcm3nrt | ora dimangertèni }}
{{Elementbox_section_atomicprop | color1=#ffc0c0 | color2=black }}
{{Elementbox_crystalstruct |ora dimangertèni }}
{{Elementbox_oxistates | 4}}
{{Elementbox_ionizationenergies1 | ora dimangertèni }}
{{Elementbox_atomicradiuscalc_pm | ora dimangertèni }}
{{Elementbox_covalentradius_pm | ora dimangertèni }}
{{Elementbox_section_miscellaneous | color1=#ffc0c0 | color2=black }}
{{Elementbox_cas_number | 53850-36-5 }}
{{Elementbox_isotopes_begin | color1=#ffc0c0 | color2=black }}
{{Elementbox_isotopes_decay | mn=267 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=1.3 h | dm=SF | de= | pn= | ps= }}
{{Elementbox_isotopes_decay2 | mn=263m | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=~15 m | dm1=SF | de1= | pn1= | ps1= |dm2=α | de2=7.90 ? | pn2= | ps2= }}
{{Elementbox_isotopes_decay | mn=263g | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=8 s| dm=SF | de= | pn= | ps= }}
{{Elementbox_isotopes_decay | mn=262 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=2.1 s| dm=SF | de= | pn= | ps= }}
{{Elementbox_isotopes_decay | mn=261m | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=1.1 m| dm=[[alpha decay|α]] | de=8.28 | pn=257 | ps=No }}
{{Elementbox_isotopes_decay2 | mn=261g | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=3.7 s | dm1=83% SF | de1= | pn1= | ps1= |dm2=17% α | de2=8.52 | pn2=257 | ps2=No }}
{{Elementbox_isotopes_decay | mn=260 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=20 ms| dm=SF| de=| pn= | ps= }}
{{Elementbox_isotopes_decay2 | mn=259 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=3.1 s| dm1=93% α | de1=8.87,8.77 | pn1=255 | ps1=No |dm2=7% SF | de2=| pn2= | ps2= }}
{{Elementbox_isotopes_decay | mn=258 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=13 ms| dm=SF| de= | pn=| ps= }}
{{Elementbox_isotopes_decay | mn=257m | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=4.0 s| dm=α| de=9.02,8.97 | pn=253| ps=No }}
{{Elementbox_isotopes_decay2 | mn=257g | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=3.5 s| dm1=89% α | de1=8.90,8.78,8.52,8.28 | pn1=253 | ps1=No |dm2=11% [[electron capture|ε]] | de2=| pn2=257 | ps2=Lr}}
{{Elementbox_isotopes_decay2 | mn=256 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=6.2 ms | dm1=99.7% SF | de1= | pn1= | ps1= |dm2=0.3% α | de2=8.79 | pn2=252 | ps2=No }}
{{Elementbox_isotopes_decay2 | mn=255 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=1.8 s | dm1=~50% α | de1=8.81,8.77,8.74,8.71| pn1=251 | ps1=No |dm2=~50% SF | de2= | pn2= | ps2=  }}
{{Elementbox_isotopes_decay | mn=254 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=0.022 ms| dm=SF| de= | pn=| ps= }}
{{Elementbox_isotopes_decay | mn=253 | sym=Rf | na=[[synthetic radioisotope|syn]] | hl=0.048 ms| dm=SF| de= | pn=| ps= }}
{{Elementbox_isotopes_end}}
{{Elementbox_footer | color1=#ffc0c0 | color2=black }}

'''Rutherfordium''' ({{pronEng|ˌrʌðɚˈfɔrdiəm}}) iku [[unsur kimia]] sajeroning  [[Tabel périodik]] kanthi simbul '''Rf''' lan [[nomer atom]] [[104]]. 
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This is a [[radioactive]] [[synthetic element]] whose most stable known [[isotope]] is <sup>267</sup>Rf with a [[half-life]] of approximately 1.3 hours. Chemistry experiments have confirmed that rutherfordium behaves as the heavier homologue to hafnium in group 4 (see below).

==Official discovery==
Element 104 was reportedly [[discovery of the chemical elements|first detected]] in 1966 at the [[JINR|Joint Institute of Nuclear Research ]] at [[Dubna]] ([[U.S.S.R.]]). Researchers there bombarded <sup>242</sup>[[plutonium|Pu]] with accelerated <sup>22</sup>[[neon|Ne]] [[ion]]s and separated the reaction products by gradient thermochromatography after conversion to chlorides by interaction with ZrCl<sub>4</sub>. The team identified a [[spontaneous fission]] activity contained within a volatile chloride portraying eka-hafnium properties. Although a half-life was not accurately determined, later calculations indicated that the product was most likely <sup>259</sup>Rf:<ref name=93TWG>[http://www.iupac.org/publications/pac/1993/pdf/6508x1757.pdf "DISCOVERY OF THE TRANSFERMIUM ELEMENTS"], '''IUPAC/IUPAP Technial Report''', ''Pure & Appl. Chem.'', Vol. 65, No. 8, pp. 1757-1814,1993. Retrieved on [[2008-03-04]]</ref>

:<math>\, ^{242}_{94}\mathrm{Pu} + \, ^{22}_{10}\mathrm{Ne} \to \, ^{264-x}_{104}\mathrm{Rf}\to \,^{264-x}_{104}\mathrm{RfCl}_{4}</math>

The Russian scientists proposed the name ''Kurchatovium'' for the new element.

In 1969 researchers at the [[University of California, Berkeley]] conclusively synthesized the element by bombarding a [[californium|Cf]]-249 target with carbon-12 ions and measured the alpha decay of <sup>257</sup>104, correlated with the daughter decay of <sup>253</sup>102.
<ref name=69Gh01>[http://prola.aps.org/abstract/PRL/v22/i24/p1317_1 "Positive Identification of Two Alpha-Particle-Emitting Isotopes of Element 104"], '''Ghiorso et al'''., ''Phys. Rev. Lett. 22'', 1317-1320 (1969). Retrieved on [[2008-03-04]]</ref>

:<math>\,^{249}_{98}\mathrm{Cf}\ + \,^{12}_{6}\mathrm{C}\to \,^{257}_{104}\mathrm{Rf}\ + 4   \,^{1}_{0}\mathrm{n}</math>

The American scientists proposed the name ''Rutherfordium'' for the new element.

The American synthesis was independently confirmed in 1973 and secured the identification of element 104 as the parent by the observation of K X-rays in the elemental signature of the daughter <sup>253</sup>No.
<ref name=73Be01>[http://prola.aps.org/abstract/PRL/v31/i10/p647_1 "X-Ray Identification of Element 104"], '''Bemis et al.''', ''Phys. Rev. Lett. 31'', 647-650 (1973). Retrieved on [[2008-03-04]]</ref>

In 1992 the IUPAC/IUPAP Transfermium Working Group (TWG) assessed the claims of discovery and concluded that both teams provided contemporaneous evidence to the synthesis of element 104 and that credit should be shared between the two groups.<ref name=93TWG/>

The American group wrote a scathing response to the findings of the TWG, stating that they had given too much emphasis on the results from the Dubna group. In particular they pointed out that the Russian group had altered the details of their claims several times over a period of 20 years, a fact which the Russian team do not deny. They also stressed that the TWG had given too much credence to the chemistry experiments performed by the Russians and accused the TWG of not having appropriately qualified personnel on the committee. The TWG responded by saying that this was not the case and having assessed each point raised by the American group said that they found no reason to alter their conclusion regarding priority of discovery.
<ref>[http://www.iupac.org/publications/pac/1993/pdf/6508x1815.pdf "Responses on the Report DISCOVERY OF THE TRANSFERMIUM ELEMENTS"], ''Pure & Appl. Chem.'',Vol. 65, No. 8, pp. 1815-1824, 1993. Retrieved on [[2008-04-03]]</ref> 
It should be said that IUPAC finally used the name suggested by the American team (''rutherfordium'') which may in some way reflect a change of opinion.<ref name=97IUPAC>[http://www.iupac.org/publications/pac/1997/pdf/6912x2471.pdf "NAMES AND SYMBOLS OF TRANSFERMIUM ELEMENTS"], '''IUPAC''', ''Pure & Appl. Chem.'', Vol. 69, No. 12, pp. 2471-2473, 1997. Retrieved on [[2008-04-03]]</ref>

As a consequence of the initial competing claims of discovery, an [[element naming controversy]] arose. Since the Soviets claimed to have first detected the new element they suggested the name ''kurchatovium'' ({{pronEng|ˌkɝtʃəˈtoʊviəm}}, Ku, in honor of [[Igor Vasilevich Kurchatov]] ([[1903]]-[[1960]]), former head of [[Soviet nuclear research]]. 
The Americans, however, proposed ''rutherfordium'' (Rf) for the new element to honor [[Ernest Rutherford, 1st Baron Rutherford of Nelson|Ernest Rutherford]], who is known as the "father" of [[nuclear physics]]. 
The International Union of Pure and Applied Chemistry ([[IUPAC]]) adopted ''unnilquadium'' ({{IPA|/ˌjuːn<s>ɪ</s>lˈkwɒdiəm/}}, Unq, as a temporary, [[systematic element name]], derived from the Latin names for digits 1, 0, and 4. In 1994, IUPAC suggested the name ''dubnium'' to be used since ''rutherfordium'' was suggested for element 106 and IUPAC felt that the Dubna team should be rightly recognised for their contributions. However, there was still a dispute over the names of elements 104-107. However in 1997 the teams involved resolved the dispute and adopted the current name ''rutherfordium''.<ref name=97IUPAC/>

==Electronic structure==

[[Image:electron shell 104 Rutherfordium.svg|thumb|150px|left]]

Rutherfordium is element 104 in the Periodic Table. The two forms of the projected electronic structure are:

Bohr model: 2, 8, 18, 32, 32, 10, 2

Quantum mechanical model: 1s<sup>2</sup>2s<sup>2</sup>2p<sup>6</sup>3s<sup>2</sup>3p<sup>6</sup>4s<sup>2</sup>3d<sup>10</sup>
4p<sup>6</sup>5s<sup>2</sup>4d<sup>10</sup>5p<sup>6</sup>6s<sup>2</sup>4f<sup>14</sup>5d<sup>10</sup>
6p<sup>6</sup>7s<sup>2</sup>5f<sup>14</sup>6d<sup>2</sup>

==Extrapolated chemical properties of eka-hafnium/dvi-zirconium==
===Oxidation states===
Element 104 is projected to be the first member of the 6d series of transition metals and the heaviest member of group IV in the Periodic Table, below [[titanium]],[[zirconium]] and [[hafnium]].
The IV oxidation state is the only stable state for the latter two elements and therefore rutherfordium should also portray a stable +4 state.

===Chemistry===
In an analogous manner to zirconium and hafnium, rutherfordium is projected to form a very stable, high melting point oxide, RfO<sub>2</sub>. It should also react with halogens to form tetrahalides, RfX<sub>4</sub>, which hydrolyse on contact with water to form oxyhalides RfOX<sub>2</sub>. The tetrahalides should be volatile solids existing as monomeric tetrahedral molecules in the vapour phase.
In the aqueous phase, the Rf<sup>4+</sup> ion should hydrolyse less than titanium(IV) and to a similar extent to zirconium and hafnium, thus leading to the rutherfordyl oxyion, RfO<sub>2</sub><sup>2+</sup>. Treatment of the halides with halide ions promotes the formation of complex ions. The use of chloride and bromide ion should form the hexahalide complexes RfCl<sub>6</sub><sup>2-</sup> and RfBr<sub>6</sub><sup>2-</sup>. For the fluoride complexes, [[zirconium]] and [[hafnium]] tend to form hepta- and octa- complexes. Thus, for the larger rutherfordium ion, the complexes RfF<sub>6</sub><sup>2-</sup>, RfF<sub>7</sub><sup>3-</sup> and RfF<sub>8</sub><sup>4-</sup> are possible.

==Experimental chemistry==
===Gas phase chemistry===
Early work on the study of the chemistry of rutherfordium focused on gas thermochromatography and measurement of relative deposition temperature adsorption curves. The initial work was carried out at Dubna in an attempt to reaffirm their discovery of the element. Recent work is more reliable regarding the identification of the parent rutherfordium radioisotopes. The isotope <sup>261m</sup>Rf has been used for these studies. 
The experiments relied on the expectation that rutherfordium would begin the new 6d series of elements and should therefore from a volatile tetrachloride due to the tetrahedral nature of the molecule:

[[Image:RfCl4.png|thumb|100px|left|The tetrahedral molecule RfCl<sub>4</sub>]]

As series of experiments have confirmed that rutherfordium behaves as a typical member of group 4 forming a tetravalent chloride (RfCl<sub>4</sub>) and bromide (RfBr<sub>4</sub>) as well as an oxychloride (RfOCl<sub>2</sub>).
<ref>http://lch.web.psi.ch/pdf/TexasA&M/TexasA&M.pdf (Gas Chem 2007 Review)</ref>

===Aqueous phase chemistry===
Rutherfordium is expected to have the electron configuration [Rn]5f<sup>14</sup> 6d<sup>2</sup> 7s<sup>2</sup> and therefore behave as the heavier homologue of [[hafnium]] in group 4 of the [[Periodic Table]]. It should therefore readily form a hydrated Rf<sup>4+</sup> ion in strong acid solution and should readily form complexes in hydrochloric acid, hydrobromic or hydrofluoric acid solutions.
The most conclusive aqueous chemistry studies of rutherfordium have been performed by the Japanese tean at JAERI using the radioisotope <sup>261m</sup>Rf. Extraction experiments from hydrochloric acid solutions using isotopes of rutherfordium, hafnium, zirconium and thorium have proved a non-actinide behaviour. A comparison with its lighter homologues placed rutherfordium firmly in group 4 and indicated the formation of a hexachlororutherfordate complex in chloride solutions, in a  manner similar to hafnium and zirconium.
<ref>http://wwwsoc.nii.ac.jp/jnrs/paper/JN62/jn6202.pdf (Rf aqueous chem JAERI)</ref>

:<math>\,^{261m}\mathrm{Rf} + 6\mathrm{Cl}^{-}\, \to\ [\,^{261m}\mathrm{RfCl}_{6}]^{2-}</math>

Very similar results were observed in hydrofluoric acid solutions. Differences in the extraction curves were interpreted as a weaker affinity for fluoride ion and the formation of the hexafluororutherfordate ion, whereas hafnium and zirconium ions complex seven or eight fluoride ions at the concentrations used:

:<math>\,^{261m}\mathrm{Rf} + 6\mathrm{F}^{-}\, \to\ [\,^{261m}\mathrm{RfF}_{6}]^{2-}</math>

===Summary of compounds and complex ions===

{| class="wikitable"
|-
! Formula
! Names(s)
|-
| RfCl<sub>4</sub>
| rutherfordium tetrachloride ; rutherfordium(IV) chloride
|-
| RfBr<sub>4</sub>
| rutherfordium tetrabromide ; rutherfordium(IV) bromide
|-
| RfOCl<sub>2</sub>
| rutherfordium oxychloride ; rutherfordium(IV) dichloride oxide ; rutherfordyl(IV) chloride
|-
| [RfCl<sub>6</sub>]<sup>2-</sup>
| hexachlororutherfordate(VI)
|-
| [RfF<sub>6</sub>]<sup>2-</sup>
| hexafluororutherfordate(VI)
|-
| K<sub>2</sub>[RfCl<sub>6</sub>]
| potassium hexachlororutherfordate(VI)
|}

==History of synthesis of isotopes by cold fusion==
===<sup>208</sup>Pb(<sup>50</sup>Ti,xn)<sup>258-x</sup>Rf (x=1,2,3)===
This reaction was first studied in 1974 by the team at Dubna. They measured a spontaneous fission activity assigned to <sup>256</sup>Rf.
<ref>[http://www.springerlink.com/content/m87v320736564810/ "Experiments on the synthesis of neutron-deficient isotopes of kurchatovium in reactions with accelerated <sup>50</sup>Ti ions"], '''Oganesyan et al'''., ''Nucl. Phys. A.'', 1975, 36, 6. Retrieved on [[2008-02-29]]</ref> 
The reaction was further studied in 1985 by the GSI team who measured the decay properties of the isotopes <sup>257</sup>Rf and <sup>256</sup>Rf. The team were able to determine some initial spectroscopic properties of <sup>257</sup>Rf and found that the alpha decay pattern was very complicated.
<ref>[http://www.springerlink.com/content/g721435j48022485/ "Study of evaporation residues produced in reactions of <sup>207</sup>,<sup>208</sup>Pb with <sup>50</sup>Ti"], '''Hessberger et al.''',  ''Z. Physik'' ,1984, 316, 19-26. Retrieved on [[2008-02-29]]</ref>

After an upgrade of their facilities, they repeated the reaction in 1994 with much higher sensitivity and detected some 1100 atoms of <sup>257</sup>Rf and 1900 atoms of <sup>256</sup>Rf along with <sup>255</sup>Rf in the measurement of the 1n,2n and 3n excitation functions. The large amount of decay data for <sup>257</sup>Rf allowed the detection of an isomeric level and the construction of a partial decay level structure which confirmed the very complicated alpha decay pattern. They also found evidence for an isomeric level in <sup>255</sup>Rf.
<ref name=97He01>[http://www.springerlink.com/content/5hbgbgywe6q38ujf/ "Spontaneous fission and alpha-decay properties of neutron deficient isotopes <sup>257-253</sup>104 and <sup>258</sup>106"], '''Hessberger et al.''', ''Z. Phys. A'', 359, 4, 1997. Retrieved on [[2008-02-29]]</ref> 
The GSI team continued in 2001 with the measurement of the 3n excitation function.
In 2002, scientists at the Argonne University in Illinois began their first studies of translawrencium elements with the synthesis and alpha-gamma spectroscopy of <sup>257</sup>Rf.<ref>[http://adsabs.harvard.edu/abs/2007APS..DNP.JG010Q "Alpha decay of <sup>257</sup>Rf"], '''Qian et al.''', ''American Physical Society, 2007 Annual Meeting of the Division of Nuclear Physics'', October 10-13, 2007. Retrieved on [[2008-02-28]]</ref>
In 2004, the GSI began their spectroscopic studies of the <sup>257</sup>Rf isotope.

===<sup>207</sup>Pb(<sup>50</sup>Ti,xn)<sup>257-x</sup>Rf (x=2)===
This reaction was first studied in 1974 by the team at Dubna. They measured a spontaneous fission activity assigned to <sup>255</sup>Rf. The reaction was further studied in 1985 by the GSI team who measured the decay properties of the isotope <sup>255</sup>Rf. A further spectroscopic study was reported in 2000 which led to a first decay level scheme for the isotope.<ref>[http://www.edpsciences.org/articles/epja/abs/2001/09/epja1103/epja1103.html "Decay properties of neutron-deficient isotopes <sup>256,257</sup>Db, <sup>255</sup>Rf, <sup>252,253</sup>Lr"], '''Hessberger et al.''', ''Eur. Phys. J.'', A 12, 57-67 (2001). Retrieved on [[2008-02-29]]</ref> The isomeric level proposed in 1994 was not found. In 2006, the spectroscopy was continued and the decay scheme was confirmed and improved.
<ref>[http://www.edpsciences.org/articles/epja/abs/2006/15/10050_2006_Article_100239/10050_2006_Article_100239.html "Alpha-gamma decay studies of <sup>255</sup>Rf, <sup>251</sup>No and <sup>247</sup>Fm"], '''Hessberger et al'''., ''Eur. Phys. J. A 30'', 561-569 (2006). Retrieved on [[2008-03-04]]</ref>

===<sup>206</sup>Pb(<sup>50</sup>Ti,xn)<sup>256-x</sup>Rf (x=1,2)===
The team at GSI first studied this reaction in 1994 in an effort to study neutron deficient isotopes of rutherfordium. They were able to detect <sup>255</sup>Rf and 144 atoms of the new isotope <sup>254</sup>Rf, which decayed by [[spontaneous fission]].<ref name=97He01/>

===<sup>204</sup>Pb(<sup>50</sup>Ti,xn)<sup>254-x</sup>Rf (x=1)===
The team at GSI first studied this reaction in 1994 in an effort to study neutron deficient isotopes of rutherfordium. They were able to detect 14 atoms of the new isotope <sup>253</sup>Rf, which decayed by [[spontaneous fission]].<ref name=97He01/>

===<sup>208</sup>Pb(<sup>48</sup>Ti,xn)<sup>256-x</sup>Rf (x=1)===
In 2006, as part of a program looking at the effect of isospin on the mechanism of cold fusion, the team at LBNL studied this reaction. They measured the 1n excitation function and determined that the change of a Ti-50 projectile to a Ti-48 one significantly reduced the yield, in agreement with predictions.
<ref>[http://rnc.lbl.gov/nsd/annualreport2005/contributions/Dragojevic_LE.pdf "Measurement of <sup>208</sup>Pb(<sup>48</sup>Ti,n)<sup>255</sup>Rf excitation function"], '''Dragojevic et al.''', ''LBNL annual report 2005''. Retrieved on [[2008-02-29]]</ref>

===<sup>124</sup>Sn(<sup>136</sup>Xe,xn)<sup>260-x</sup>Rf===
In an important study, in May 2004, the team at GSI attempted the symmetric synthesis of rutherfordium by attempting to fuse two fission fragments. Theory suggests that there may be an enhancement of the yield. No product atoms were detected and a limit of 1000 pb was calculated.

==History of synthesis of isotopes by hot fusion==
===<sup>238</sup>U(<sup>26</sup>Mg,xn)<sup>264-x</sup>Rf (x=3,4,5,6)===
The hot fusion reaction using a uranium target was first reported in 2000 by Yuri Lazarev and the team at the Flerov Laboratory of Nuclear Reactions (FLNR). They were able to observe decays from <sup>260</sup>Rf and <sup>259</sup>Rf in the 4n and 5n channels.
<ref>[http://prola.aps.org/abstract/PRC/v62/i6/e064307 "Decay properties of <sup>257</sup>No, <sup>261</sup>Rf, and <sup>262</sup>Rf"], '''Lazarev et al.''', [[''Phys. Rev. C'']] 62, 064307 (2000). Retrieved on [[2008-02-29]]</ref> 
They measured yields of 240 pb in the 4n channel and 1.1 nb in the 5n channel.
In 2006, as part of their program on the study of uranium targets in hot fusion reactions, the team at LBNL measured the 4n,5n and 6n excitation functions for this reaction and observed <sup>261</sup>Rf in the 3n exit channel.
<ref>[http://rnc.lbl.gov/nsd/annualreport2005/contributions/Gregorich_LE.pdf "Systematic Study of Heavy Element Production in Compound Nucleus Reactions with <sup>238</sup>U Targets"], '''Gregorich et al.''', ''LBNL Annual Report 2005''. Retrieved on [[2008-02-29]]</ref><ref>[http://prc.aps.org/accepted "Synthesis of rutherfordium isotopes in the <sup>238</sup>U(<sup>26</sup>Mg,xn)<sup>264-x</sup>Rf reaction and study of their decay properties"], '''Gates et al.''', ''Phys. Rev. C'', Accepted 29-01-2008. Retrieved on [[2008-02-29]]</ref>

===<sup>244</sup>Pu(<sup>22</sup>Ne,xn)<sup>266-x</sup>Rf (x=4,5)===
This reaction was reported in 1996 at LBNL in an attempt to study the fission characteristics of <sup>262</sup>Rf. The team were able to detect the SF of <sup>262</sup>Rf and determine its half-life as 2.1 s, in contrast to earlier reports of a 47 ms activity. It was suggested that the two half-lives may be related to different isomeric states.
<ref name=96La01>[http://prola.aps.org/abstract/PRC/v53/i6/p2893_1 "Spontaneous fission properties of <sub>104</sub><sup>262</sup>Rf "], '''Lane et al'''., ''Phys. Rev. C 53'', 2893 - 2899 (1996). Retrieved on [[2008-04-03]]</ref>
The reaction was further studied in 2000 by Yuri Lazarev and the team at Dubna. They were able to observe 69 alpha decays from <sup>261</sup>Rf and [[spontaneous fission]] of <sup>262</sup>Rf.
<ref>[http://prola.aps.org/abstract/PRC/v62/i6/e064307 "Decay properties of <sup>257</sup>No, <sup>261</sup>Rf, and <sup>262</sup>Rf"], '''Lazarev et al.''', ''Phys. Rev. C 62'', 064307 (2000). Retrieved on [[2008-03-04]]</ref>
Later work on [[hassium]] has allowed a reassignment of the 5n product to <sup>261m</sup>Rf.

===<sup>242</sup>Pu(<sup>22</sup>Ne,xn)<sup>264-x</sup>Rf (x=3,4?,5?)===
The synthesis of element 104 was first attempted in 1964 by the team at Dubna using this reaction. The first study produced evidence for a 0.3 s [[spontaneous fission]] (SF) activity tentatively assigned to <sup>260</sup>104 or <sup>259</sup>104 and an unidentified 8 s SF activity. The former activity was later retracted and the latter activity associated with the now-known <sup>259</sup>104.<ref name=93TWG/>
In 1966, in their discovery experiment, the team repeated the reaction using a chemical study of volatile chloride products. The group was able to identify a volatile chloride decaying by short [[spontaneous fission]] with eka-hafnium properties. This gave strong evidence for the formation of [104]Cl<sub>4</sub> and the team suggested the name ''kurchatovium''. Although a half-life was not accurately measured, later evidence suggested that the product was most likely <sup>259</sup>104.
<ref name=93TWG/>
In 1968, the team searched for alpha decay from <sup>260</sup>104 but were unable to detect such activity. In 1970, the team repeated the reaction once again and confirmed the ~0.2 s SF activity. They also repeated the chemistry experiment and obtained identical results to their 1966 experiment and calculated a likely half-life of ~0.5 seconds for the SF activity. In 1971, the reaction was repeated again and 0.1 s and 4.5 s SF activities were found. The 4.5 s activity was correctly assigned to <sup>259</sup>104.<ref name=93TWG/>
A chemistry experiment in the same year reaffirmed the formation of a 0.3 SF activity for an eka-hafnium product.<ref name=93TWG/>
Later, the 0.1-0.3 s SF activity was retracted as belonging to a kurchatovium isotope but the observation of eka-hafnium reactivity remained and was the basis of their successful claim to discovery.<ref name=93TWG/>
The reaction was further studied in 2000 by Yuri Lazarev at [[Dubna]]. They were able to observe <sup>261</sup>Rf in the 3n channel, later reassigned to <sup>261m</sup>Rf.

===<sup>242</sup>Pu(<sup>20</sup>Ne,xn)<sup>262-x</sup>Rf===
This reaction was first studied in 1964 to assist in the assignments using the analogous reaction with a Ne-22 beam. The Dubna team were unable to detect any 0.3 s [[spontaneous fission]] activities.<ref name=93TWG/>
The reaction was later studied in 2003 at the Paul Scherrer Institute (PSI) in Bern, Switzerland.  They detected some [[spontaneous fission]] activities but were unable to confirm the formation of <sup>259</sup>Rf.<ref>{{cite web|url=http://lch.web.psi.ch/pdf/anrep03/03.pdf |title=20Ne On 244Pu - First Preliminary Results}}</ref>

===<sup>248</sup>Cm(<sup>22</sup>Ne,αxn)<sup>266-x</sup>Rf (x=3?)===
This reaction was studied in 1999 at the University of Bern, Switzerland in order to search for the new isotope <sup>263</sup>Rf. A rutherfordium fraction was separated and several SF events with long lifetimes and alpha decays with energy 7.8 MeV and 7.9 MeV were observed. A second experiment using a study of the fluoride of rutherfordium products also produced 7.9 MeV alpha decays.<ref>[http://www.ulrich-rieth.de/publikationen/RCA0301_059.PDF "An EC-branch in the decay of 27-s <sup>263</sup>Db: Evidence for the new isotope <sup>263</sup>Rf"], '''Kratz et al.''', ''GSI Annual report 2001''. Retrieved on [[2008-02-29]]</ref>

===<sup>248</sup>Cm(<sup>18</sup>O,xn)<sup>266-x</sup>Rf (x=3?,5)===
This reaction was first studied in 1970 by Albert Ghiorso at the Lawrence Berkeley National Laboratory (LBNL). The team identified <sup>261</sup>Rf in the 5n channel using the method of correlation of genetic parent-daughter decays. A half-life of 65 s was determined.
<ref name=70Gh01>[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVN-473DDK8-15&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=f50dd21999d4152c92b105d7e4656634 "<sup>261</sup>Rf; new isotope of element 104"], '''Ghiorso et al.''', ''Phys. Lett. 32B'', 1970, 2, Pages 95-98. Retrieved on [[2008-03-04]]</ref>
A repeat later that year using cation exchange chromatography indicated that the product did not form a +2 or +3 cation and behaved as eka-hafnium.
A study of the properties of rutherfordium isotopes was performed in 1981 at the LBNL. In a series of reactions, a 1.5 s SF activity was identified and assigned to a fermium descendant although later evidence indicates a possible assignment to <sup>262</sup>Rf.
In contrast, in a subsequent review of isotope properties by Somerville et al. at LBNL in 1985, a 47 ms SF activity was assigned to <sup>262</sup>Rf. This assignment has not been verified.
<ref>[http://prola.aps.org/abstract/PRC/v31/i5/p1801_1 "Spontaneous fission of rutherfordium isotopes"], '''Somerville et al.''', ''Phys. Rev. C 31'', 1801-1815 (1985). Retrieved on [[2008-03-04]]</ref> 
The reaction was further studied in 1991 by Czerwinski et al. at the LBNL. In this experiment, [[spontaneous fission]] activities with long lifetimes were observed in rutherfordium fractions and tentatively assigned to <sup>263</sup>Rf.
In 1996, chemical studies on the chloride of rutherfordium was published by the LBNL. In this experiment, the half-life was improved to 78 s. A repeat of the experiment in 2000 assessing the volatility of the bromide further refined the half-life to 75 s.

===<sup>248</sup>Cm(<sup>16</sup>O,xn)<sup>264-x</sup>Rf (x=4)===
This reaction was studied in 1969 by Albert Ghiorso at the University of California. The aim was to detect the 0.1-0.3 s SF activity reported at Dubna, assigned to <sup>260</sup>104. They were unable to do so, only observing a 10-30 ms SF activity, correctly assigned to <sup>260</sup>104. The failure to observe the 0.3 s SF activity identified by Dubna gave the Americans the incentive to name this element ''rutherfordium''.<ref name=93TWG/>

===<sup>246</sup>Cm(<sup>18</sup>O,xn)<sup>264-x</sup>Rf===
In an attempt to unravel the properties of [[spontaneous fission]] activities in the formation of rutherfordium isotopes, this reaction was performed in 1976 by the FLNR. They observed an 80 ms SF activity. Subsequent work led to the complete retraction of the 0.3s - 0.1s - 80 ms SF activities observed by the Dubna team and associated with background signals.<ref name=93TWG/>

===<sup>249</sup>Bk(<sup>15</sup>N,xn)<sup>264-x</sup>Rf (x=4)===
This reaction was studied in 1977 by the team in Dubna. They were able to confirm the detection of a 76 ms SF activity. The assignment to rutherfordium isotopes was later retracted.
The LBNL re-studied the reaction in 1980 and in 1981 they reported that they were unable to confirm the ~80 ms SF activity. The Dubna team were able to measure a 28 ms SF activity in 1985 and assigned the isotope correctly to <sup>260</sup>104.<ref name=93TWG/>

===<sup>249</sup>Cf(<sup>13</sup>C,xn)<sup>262-x</sup>Rf (x=4)===
This use of californium-249 as a target was first studied by Albert Ghiorso and the team at the University of California in 1969. They were able to observe a 11 ms SF activity which they correctly assigned to <sup>258</sup>104.<ref name=69Gh01/>

===<sup>249</sup>Cf(<sup>12</sup>C,xn)<sup>261-x</sup>Rf (x=3,4)===
In their 1969 discovery experiments, the team at University of California also used a C-12 beam to irradiate a Cf-249 target. They were able to confirm the 11 ms SF activity found with a C-13 beam and again correctly assigned to <sup>258</sup>104. The actual discovery experiment was the observation of alpha decays genetically linked to <sup>253</sup>102 and therefore positively identified as <sup>257</sup>104.<ref name=69Gh01/> 
In 1973, Bemis and his team at Oak Ridge confirmed the discovery by measuring coincident X-rays from the daughter <sup>253</sup>102.<ref name=73Be01/> 
-->
== Sintesis isotop minangka produk turunan (''decay'') ==
<!--
Isotopes of rutherfordium have also been identified in the decay of heavier elements. Observations to date are summarised in the table below:
-->
{| class="wikitable"
|-
! Sisa/residu Evaporasi
! Isotop Rf kang katon
|-
| <sup>288</sup>115 
| <sup>268</sup>Rf (manawa EC saka <sup>268</sup>Db)
|-
| <sup>291</sup>116, <sup>287</sup>114, <sup>283</sup>112    
| <sup>267</sup>Rf
|-
| <sup>282</sup>113 
| <sup>266</sup>Rf (EC of <sup>266</sup>Db)
|-
| <sup>271</sup>Hs  
| <sup>263g</sup>Rf
|-
| <sup>263</sup>Db 
| <sup>263m</sup>Rf (EC of <sup>263</sup>Db)
|-
| <sup>266</sup>Sg (possibly <sup>266m</sup>Sg) 
| <sup>262</sup>Rf (possibly <sup>262m</sup>Rf)
|-
| <sup>277</sup>112, <sup>273</sup>Ds, <sup>269</sup>Hs, <sup>265</sup>Sg   
| <sup>261m</sup>Rf, <sup>261</sup>Rf 
|-
| <sup>271</sup>Ds, <sup>267</sup>Hs, <sup>263</sup>Sg 
| <sup>259</sup>Rf
|-
| <sup>269</sup>Ds, <sup>265</sup>Hs, <sup>261</sup>Sg   
| <sup>257</sup>Rf
|-
| <sup>264</sup>Hs, <sup>260</sup>Sg 
| <sup>256</sup>Rf
|-
| <sup>259</sup>Sg 
| <sup>255</sup>Rf
|}

== Kronologi temon isotop ==

{| class="wikitable"
|-
! Isotop
! Taun tinemu
! reaksi
|-
| <sup>253</sup>Rf
| 1994
| <sup>204</sup>Pb(<sup>50</sup>Ti,n) <ref name=97He01/>
|-
| <sup>254</sup>Rf
| 1994
| <sup>206</sup>Pb(<sup>50</sup>Ti,2n) <ref name=97He01/>
|-
| <sup>255</sup>Rf
| 1974? 1985
| <sup>207</sup>Pb(<sup>50</sup>Ti,2n)
|-
| <sup>256</sup>Rf
| 1974? 1985
| <sup>208</sup>Pb(<sup>50</sup>Ti,2n)
|-
| <sup>257</sup>Rf<sup>g,m</sup>
| 1969
| <sup>249</sup>Cf(<sup>12</sup>C,4n) <ref name=69Gh01/> 
|-
| <sup>258</sup>Rf
| 1969
| <sup>249</sup>Cf(<sup>13</sup>C,4n) <ref name=69Gh01/> 
|-
| <sup>259</sup>Rf
| 1969
| <sup>249</sup>Cf(<sup>13</sup>C,3n) <ref name=69Gh01/> 
|-
| <sup>260</sup>Rf
| 1969
| <sup>248</sup>Cm(<sup>16</sup>O,4n)
|-
| <sup>261</sup>Rf<sup>m</sup>
| 1970
| <sup>248</sup>Cm(<sup>18</sup>O,5n) <ref name=70Gh01/>
|-
| <sup>261</sup>Rf<sup>g</sup>
| 1996
| <sup>208</sup>Pb(<sup>70</sup>Zn,n) <ref name=E112ref>see [[kopernisium]]</ref>
|-
| <sup>262</sup>Rf
| 1996
| <sup>244</sup>Pu(<sup>22</sup>Ne,4n) <ref name=96La01/>
|-
| <sup>263</sup>Rf<sup>m</sup>
| 1990?
| <sup>248</sup>Cm(<sup>18</sup>O,3n)
|-
| <sup>263</sup>Rf<sup>g</sup>
| 2004
| <sup>248</sup>Cm(<sup>26</sup>Mg,3n) <ref>see [[hassium]]</ref>
|-
| <sup>264</sup>Rf
| unknown
| 
|-
| <sup>265</sup>Rf
| unknown
| 
|-
| <sup>266</sup>Rf
| 2006?
| <sup>237</sup>Np(<sup>48</sup>Ca,3n) <ref name=E113ref>see [[ununtrium]]</ref>
|-
| <sup>267</sup>Rf
| 2003/2004
| <sup>238</sup>U(<sup>48</sup>Ca,3n) <ref name=E112ref/>
|-
| <sup>268</sup>Rf
| 2003?
| <sup>243</sup>Am(<sup>48</sup>Ca,3n) <ref name=E115ref>see [[ununpentium]]</ref>
|}
<!--
==Isomerism in rutherfordium nuclides==
===<sup>263</sup>Rf===
Initial work on the synthesis of rutherfordium isotopes by hot fusion pathways focused on the synthesis of <sup>263</sup>Rf. Several studies have indicated that this nuclide decays primarily by [[spontaneous fission]] with a long [[half-life]] of 10-20 minutes. Alpha particles with energy 7.8-7.9 MeV have also been associated with this nucleus. More recently, a study of [[hassium]] [[isotope]]s allowed the synthesis of an atom of <sup>263</sup>Rf decaying by [[spontaneous fission]] with a short [[half-life]] of 8 seconds. These two different decay modes must be associated with two isomeric states. Specific assignments are difficult due to the low number of observed events. It is reasonable to tentatively assign the long-liver to a meta-stable state, namely <sup>263m</sup>Rf, and the shorter-liver to the ground state, namely <sup>263g</sup>Rf. Further studies are required to allow a definite assignment.

===<sup>261</sup>Rf===
Early research on the synthesis of rutherfordium isotopes utilised the <sup>244</sup>Pu(<sup>22</sup>Ne,5n)<sup>261</sup>Rf reaction. The product was found to undergo exclusive 8.28 MeV [[alpha decay]] with a [[half-life]] of 78 seconds. Later studies by the [[GSI]] team on the synthesis of [[ununbium|element 112]] and [[hassium]] isotopes produced conflicting data. In this case, <sup>261</sup>Rf was found to undergo 8.52 MeV alpha decay with a short half-life of 4 seconds. Later results indicated a predominant fission branch. These contradictions led to some doubt on the discovery of [[ununbium|element 112]]. However, it is now understood that the first nucleus belongs to an isomeric meta-stable state, namely <sup>261m</sup>Rf and the latter to the ground state isomer, namely <sup>261g</sup>Rf.
<ref>[http://lch.web.psi.ch/pdf/anrep01/B-02heavies.pdf "EVIDENCE FOR ISOMERIC STATES IN <sup>261</sup>Rf"], '''Dressler et al.''', ''PSI Annual Report 2001''. Retrieved on [[2008-01-29]]</ref>  
The discovery and confirmation of <sup>261g</sup>Rf provided proof for the discovery of [[ununbium]] in 1996.

===<sup>257</sup>Rf===
A detailed spectroscopic study of the production of <sup>257</sup>Rf nuclei using the reaction <sup>208</sup>Pb(<sup>50</sup>Ti,n)<sup>257</sup>Rf allowed the identification of an isomeric level in <sup>257</sup>Rf. The work confirmed that <sup>257g</sup>Rf has a very complicated spectrum with as many as 15 alpha lines. A level structure diagram was calculated for both isomers.

==Spectroscopic decay level schemes for rutherfordium isotopes==
===<sup>257</sup>Rf=== 
[[Image:257Rf decay scheme 2006.png|thumb|325px|none|This is the currently suggested decay level scheme for <sup>257</sup>Rf<sup>g,m</sup> from the study performed in 2004 by Hessberger et al. at GSI]]<ref name=97He01/>

===<sup>255</sup>Rf=== 
[[Image:255Rf decay scheme 2006.png|thumb|325px|none|This is the currently suggested decay level scheme for <sup>255</sup>Rf from the study reported in 2007 by Hessberger et al. at GSI]]

==Unconfirmed isotopes==
===<sup>268</sup>Rf===
In the synthesis of [[ununpentium]], the isotope <sup>288</sup>115 has been observed to decay to <sup>268</sup>Db which undergoes [[spontaneous fission]] with a half life of 29 hours. Given that the [[electron capture]] of <sup>268</sup>Db cannot be detected, these SF events may in fact be due to the SF of <sup>268</sup>Rf, in which case the half-life of this isotope cannot be extracted.
<ref name=E115ref/>

===<sup>266</sup>Rf===
In the synthesis of [[ununtrium]], the isotope <sup>282</sup>113 has been observed to decay to <sup>266</sup>Db which undergoes [[spontaneous fission]] with a half life of 22 minutes. Given that the [[electron capture]] of <sup>266</sup>Db cannot be detected, these SF events may in fact be due to the SF of <sup>266</sup>Rf, in which case the half-life of this isotope cannot be extracted.
<ref name=E113ref/>

==Retracted isotopes==
===<sup>265</sup>Rf===
In 1999, American scientists at the University of California, Berkeley, announced that they has succeeded in synthesizing three atoms of <sup>293</sup>118. These parent nuclei successively emitted seven alpha particles to form <sup>265</sup>Rf nuclei. Their claim was retracted in 2001. As such, this rutherfordium isotope is unconfirmed or unknown.<ref>see [[ununoctium]]</ref>

===<sup>255m</sup>Rf===
A detailed spectroscopic study of the production of <sup>255</sup>Rf nuclei using the reaction <sup>206</sup>Pb(<sup>50</sup>Ti,n)<sup>255</sup>Rf allowed the tentative identification of an isomeric level in <sup>255</sup>Rf. A more detailed study later confirmed that this was not the case.
-->
== Kasil kimia saka isotop ==
=== Fusi adhem ===
<!--
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.
-->
{| class="wikitable"
|-
! Proyektil
! Target
! CN
! 1n 
! 2n
! 3n
|-
| <sup>50</sup>Ti
| <sup>208</sup>Pb
| <sup>258</sup>Rf
| '''38.0 nb, 17.0 MeV'''
| '''12.3 nb, 21.5 MeV'''
| '''660 pb, 29.0 MeV'''
|-
| <sup>50</sup>Ti 
| <sup>207</sup>Pb
| <sup>257</sup>Rf
| 4.8 nb
| 
|
|-
| <sup>50</sup>Ti 
| <sup>206</sup>Pb
| <sup>256</sup>Rf
| 800 pb, 21.5 MeV
| 2.4 nb, 21.5 MeV
|
|-
| <sup>50</sup>Ti 
| <sup>204</sup>Pb
| <sup>254</sup>Rf
| 190 pb, 15.6 MeV
| 
|
|-
| <sup>48</sup>Ti 
| <sup>208</sup>Pb
| <sup>256</sup>Rf
| '''380 pb, 17.0 MeV'''
|
| 
|}

=== Fusi panas ===
<!--
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.
-->
{| class="wikitable"
|-
! Proyektil
! Target
! CN
! 3n 
! 4n
! 5n
|-
| <sup>26</sup>Mg
| <sup>238</sup>U
| <sup>264</sup>Rf
| 
| 240 pb
| 1.1 nb
|-
| <sup>22</sup>Ne 
| <sup>244</sup>Pu
| <sup>266</sup>Rf
| 
| +
| 4.0 nb
|-
| <sup>18</sup>O
| <sup>248</sup>Cm
| <sup>266</sup>Rf
| 
| +
| 13.0 nb
|}
<!--
==Future experiments==
The team at GSI are planning to perform first detailed spectroscopic studies on the isotope <sup>259</sup>Rf. It will be produced in the new reaction:

:<math>\,^{238}_{92}\mathrm{U}\ + \,^{24}_{12}\mathrm{Mg}\to \,^{259}_{104}\mathrm{Rf}\ + 3   \,^{1}_{0}\mathrm{n}</math>
== Rujukan ==
{{reflist|2}}
-->

== Rujukan ==
{{reflist}}

== Pranala njaba ==
* [http://www.webelements.com/webelements/elements/text/Rf/index.html WebElements.com - Rutherfordium]

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