isotopes of ununpentium - wikipedia, the free encyclopedia

From Wikipedia, the free encyclopedia

Ununpentium (Uup) is an artificial element, and thus a standard atomic mass cannot be given. Like all artificialelements, it has no stable isotopes. The first isotope to be synthesized was 288Uup in 2004. There are fourknown radioisotopes from 287Uup to 290Uup.

1 Table1.1 Notes

2 Nucleosynthesis2.1 Target-projectile combinations2.2 Hot fusion

2.2.1 238U(51V,xn)289−xUup2.2.2 243Am(48Ca,xn)291−xUup (x=2,3,4)2.2.3 Reaction yields

2.3 Theoretical calculations2.3.1 Decay characteristics2.3.2 Evaporation residue cross sections

3 References

nuclidesymbol Z(p) N(n)

isotopic mass (u)

half-life decay mode(s) daughter

isotope(s)nuclear

spin

287Uup 115 172 287.19070(52)# 32(+155-14) ms α 283Uut288Uup 115 173 288.19274(62)# 87(+105-30) ms α 284Uut289Uup[n 1] 115 174 289.19363(89)# 220 ms[1] α 285Uut290Uup[n 2] 115 175 290.19598(73)# 16 ms[1] α 286Uut

^ Not directly synthesized, created as decay product of 293Uus1.^ Not directly synthesized, created as decay product of 294Uus2.

Notes

Values marked # are not purely derived from experimental data, but at least partly from systematic trends.Spins with weak assignment arguments are enclosed in parentheses.Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertaintyvalues denote one standard deviation, except isotopic composition and standard atomic mass from IUPACwhich use expanded uncertainties.

Isotopes of ununpentium - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Isotopes_of_ununpentium

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Chronology of isotope discoveryIsotope Year discovered Discovery reaction287Uup 2003 243Am(48Ca,4n)288Uup 2003 243Am(48Ca,3n)289Uup 2009 249Bk(48Ca,4n)[1]

290Uup 2009 249Bk(48Ca,3n)[1]

Target-projectile combinations

The table below contains various combinations of targets and projectiles which could be used to form compoundnuclei with Z=115. Each entry is acombination for which calculations have provided estimates for cross sectionyields from various neutron evaporation channels. The channel with the highest expected yield is given.

Target Projectile CN Attempt result208Pb 75As 283Uup Reaction yet to be attempted232Th 55Mn 287Uup Reaction yet to be attempted238U 51V 289Uup Failure to date

237Np 50Ti 287Uup Reaction yet to be attempted244Pu 45Sc 289Uup Reaction yet to be attempted243Am 48Ca 291Uup[2][3] Successful reaction241Am 48Ca 289Uup Planned Reaction248Cm 41K 289Uup Reaction yet to be attempted249Bk 40Ar 289Uup Reaction yet to be attempted249Cf 37Cl 286Uup Reaction yet to be attempted

Hot fusion

Hot fusion reactions are processes that create compound nuclei at high excitation energy (~40–50 MeV, hence"hot"), leading to a reduced probability of survival from fission. The excited nucleus then decays to the groundstate via the emission of 3–5 neutrons. Fusion reactions utilizing 48Ca nuclei usually produce compound nucleiwith intermediate excitation energies (~30–35 MeV) and are sometimes referred to as "warm" fusion reactions.This leads, in part, to relatively high yields from these reactions.

238U(51V,xn)289−xUup

There are strong indications that this reaction was performed in late 2004 as part of a uranium(IV) fluoridetarget test at the GSI. No reports have been published suggesting that no products atoms were detected, asanticipated by the team.[4]


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243Am(48Ca,xn)291−xUup (x=2,3,4)

This reaction was first performed by the team in Dubna in July–August 2003. In two separate runs they wereable to detect 3 atoms of 288Uup and a single atom of 287Uup. The reaction was studied further in June 2004 inan attempt to isolate the descendant 268Db from the 288Uup decay chain. After chemical separation of a +4/+5fraction, 15 SF decays were measured with a lifetime consistent with 268Db. In order to prove that the decayswere from dubnium-268, the team repeated the reaction in August 2005 and separated the +4 and +5 fractionsand further separated the +5 fractions into tantalum-like and niobium-like ones. Five SF activities wereobserved, all occurring in the +5 fractions and none in the tantalum-like fractions, proving that the product wasindeed isotopes of dubnium.

In a series of experiments between October 2010 – February 2011, scientists at the FLNR studied this reactionat a range of excitation energies. They were able to detect 21 atoms of 288115 and one atom of 289115, from the2n exit channel. This latter result was used to support the synthesis of ununseptium. The 3n excitation functionwas completed with a maximum at ~8 pb. The data was consistent with that found in the first experiments in2003.

Reaction yields

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

Projectile Target CN 2n 3n 4n 5n48Ca 243Am 291Uup 3.7 pb, 39.0 MeV 0.9 pb, 44.4 MeV

Theoretical calculations

Decay characteristics

Theoretical calculations using a quantum-tunneling model support the experimental alpha-decay half-lives.[5]

Evaporation residue cross sections

The table below contains various target-projectile combinations for which calculations have provided estimatesfor cross section yields from various neutron evaporation channels. The channel with the highest expected yieldis given.

MD = multi-dimensional; DNS = Di-nuclear system; σ = cross section

Target Projectile CN Channel (product) σmax Model Ref243Am 48Ca 291Uup 3n (288Uup) 3 pb MD [2]

243Am 48Ca 291Uup 4n (287Uup) 2 pb MD [2]

243Am 48Ca 291Uup 3n (288Uup) 1 pb DNS [3]

242Am 48Ca 290Uup 3n (287Uup) 2.5 pb DNS [3]


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^ a b c d Oganessian, Y. T.; Abdullin, F. S.; Bailey, P. D. et al. (2010). "Synthesis of a New Element with AtomicNumber Z=117" (http://www.researchgate.net/publication/44610795_Synthesis_of_a_new_element_with_atomic_number_Z__117). Physical Review Letters 104 (14):142502. Bibcode:2010PhRvL.104n2502O (http://adsabs.harvard.edu/abs/2010PhRvL.104n2502O).doi:10.1103/PhysRevLett.104.142502 (http://dx.doi.org/10.1103%2FPhysRevLett.104.142502). PMID 20481935(//www.ncbi.nlm.nih.gov/pubmed/20481935).

1.

^ a b c Zagrebaev, V (2004). "Fusion-fission dynamics of super-heavy element formation and decay"(http://nrv.jinr.ru/pdf_file/npa_04.pdf). Nuclear Physics A 734: 164. Bibcode:2004NuPhA.734..164Z(http://adsabs.harvard.edu/abs/2004NuPhA.734..164Z). doi:10.1016/j.nuclphysa.2004.01.025 (http://dx.doi.org/10.1016%2Fj.nuclphysa.2004.01.025).

2.

^ a b c Feng, Z; Jin, G; Li, J; Scheid, W (2009). "Production of heavy and superheavy nuclei in massive fusionreactions". Nuclear Physics A 816: 33. arXiv:0803.1117 (//arxiv.org/abs/0803.1117).Bibcode:2009NuPhA.816...33F (http://adsabs.harvard.edu/abs/2009NuPhA.816...33F).doi:10.1016/j.nuclphysa.2008.11.003 (http://dx.doi.org/10.1016%2Fj.nuclphysa.2008.11.003).

3.

^ "List of experiments 2000–2006" (http://web.archive.org/web/20070723094218/http://opal.dnp.fmph.uniba.sk/~beer/experiments.php). Univerzita Komenského v Bratislave.

4.

^ C. Samanta, P. Roy Chowdhury and D.N. Basu (2007). "Predictions of alpha decay half lives of heavy andsuperheavy elements". Nucl. Phys. A 789: 142–154. arXiv:nucl-th/0703086 (//arxiv.org/abs/nucl-th/0703086).Bibcode:2007NuPhA.789..142S (http://adsabs.harvard.edu/abs/2007NuPhA.789..142S).doi:10.1016/j.nuclphysa.2007.04.001 (http://dx.doi.org/10.1016%2Fj.nuclphysa.2007.04.001).

5.

Isotope masses from:M. Wang, G. Audi, A.H. Wapstra, F.G. Kondev, M. MacCormick, X. Xu, et al. (2012). "TheAME2012 atomic mass evaluation (II). Tables, graphs and references." (http://amdc.in2p3.fr/masstables/Ame2012/Ame2012b-v2.pdf). Chinese Physics C, 36 (12): 1603–2014.Bibcode:2012ChPhC..36....3M (http://adsabs.harvard.edu/abs/2012ChPhC..36....3M).doi:10.1088/1674-1137/36/12/003 (http://dx.doi.org/10.1088%2F1674-1137%2F36%2F12%2F003).G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluationof nuclear and decay properties" (http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf).Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A (http://adsabs.harvard.edu/abs/2003NuPhA.729....3A). doi:10.1016/j.nuclphysa.2003.11.001 (http://dx.doi.org/10.1016%2Fj.nuclphysa.2003.11.001).

Isotopic compositions and standard atomic masses from:J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P.Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)"(http://www.iupac.org/publications/pac/75/6/0683/pdf/). Pure and Applied Chemistry 75 (6):683–800. doi:10.1351/pac200375060683 (http://dx.doi.org/10.1351%2Fpac200375060683).M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)"(http://iupac.org/publications/pac/78/11/2051/pdf/). Pure and Applied Chemistry 78 (11):2051–2066. doi:10.1351/pac200678112051 (http://dx.doi.org/10.1351%2Fpac200678112051). Laysummary (http://old.iupac.org/news/archives/2005/atomic-weights_revised05.html).

Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talkpage.

G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluationof nuclear and decay properties" (http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf).Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A (http://adsabs.harvard.edu/abs/2003NuPhA.729....3A). doi:10.1016/j.nuclphysa.2003.11.001 (http://dx.doi.org/10.1016%2Fj.nuclphysa.2003.11.001).National Nuclear Data Center. "NuDat 2.1 database" (http://www.nndc.bnl.gov/nudat2/).


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Brookhaven National Laboratory. Retrieved September 2005.N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry andPhysics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.

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isotopes of ununpentium - wikipedia, the free encyclopedia

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