TOPICAL REVIEW: Heaviest nuclei from 48 Ca-induced reactions

After a brief introduction of the role of shell effects in determining the limiting nuclear masses, the experimental investigation of the decay properties of the heaviest nuclei is presented. For the production of superheavy nuclides fusion, reactions of heavy actinide nuclei with 48Ca-projectiles have been used. The properties of the new nuclei, the isotopes of elements 112–118, as well as of their decay products, together with the known data for the light isotopes with Z ≤ 113, give evidence of the significant increase of the stability with the neutron number of the heavy nucleus. The obtained results are discussed in the context of the theoretical predictions about the 'island of stability' of the hypothetical superheavy elements.

[1]  P. Reinhard,et al.  Systematics of fission barriers in superheavy elements , 2004 .

[2]  A. Sobiczewski.  PRESENT STATUS IN THE HALF-LIFE PREDICTIONS FOR SHE , 1978 .

[3]  V. Zagrebaev.  Fusion-fission dynamics of super-heavy element formation and decay , 2004 .

[4]  J. F. Wild,et al.  Experiments on the synthesis of element 115 in the reaction am-243(ca-48, xn) x-115-291 , 2004 .

[5]  W. Trzaska,et al.  Alpha decay of the new isotopes207, 208Ac , 1994 .

[6]  S. Antalic,et al.  New results on elements 111 and 112 , 2002 .

[7]  V. Strutinsky,et al.  Shell effects in nuclear masses and deformation energies , 1967 .

[8]  G. K. Vostokin,et al.  Synthesis of the isotopes of elements 118 and 116 in the {sup 249}Cf and {sup 245}Cm+{sup 48}Ca fusion reactions , 2006 .

[9]  Uppsala University,et al.  Search for the Production of Element 112 in the ^48Ca + ^238U , 2002 .

[10]  R. Eichler,et al.  Adsorption of Radon on Metal Surfaces: A Model Study for Chemical Investigations of Elements 112 and 114 , 2002 .

[11]  E. O. Fiset,et al.  Calculation of half-lives for superheavy nuclei , 1972 .

[12]  A. Baran,et al.  SUPERHEAVY NUCLEI IN DIFFERENT PAIRING MODELS , 2006 .

[13]  M. Itkis,et al.  Synthesis of superheavy elements with 48Ca beams , 2001 .

[14]  N. Trautmann,et al.  Isotope distributions in the reaction of /sup 238/U with /sup 238/U , 1978 .

[15]  F. A. Gareev,et al.  Closed Shells for Z > 82 and N > 126 in a Diffuse Potential Well; ZAMKNUTYE OBOLOCHKI S Z > 82 I N > 126 V RASCHETAKH S DIFFUZIONNYM POTENTSIALOM , 1966 .

[16]  J. Lattimer,et al.  The decompression of cold neutron star matter , 1977 .

[17]  J. Dechargé,et al.  Hartree-Fock-Bogolyubov calculations with the D 1 effective interaction on spherical nuclei , 1980 .

[18]  Y. Oganessian,et al.  Acceleration of 48Ca ions and new possibilities of synthesizing superheavy elements , 1976 .

[19]  J. Nix,et al.  Stability of heavy and superheavy elements , 1994 .

[20]  T. Skyrme.  The effective nuclear potential , 1958 .

[21]  Kouji Morimoto,et al.  Experiment on the Synthesis of Element 113 in the Reaction 209Bi(70Zn,n)278113 , 2004 .

[22]  W. Swiatecki,et al.  CALCULATIONS OF CROSS SECTIONS FOR THE SYNTHESIS OF SUPER-HEAVY NUCLEI IN COLD FUSION REACTIONS , 2004 .

[23]  J. F. Wild,et al.  Experiments on the synthesis of element 115 in the reaction 243 Am ( 48 Ca ,xn) 291-x 115 , 2004 .

[24]  D. Hoffman,et al.  Detection of Plutonium-244 in Nature , 1971, Nature.

[25]  W. Greiner,et al.  α-decay half-lives of superheavy nuclei , 2006 .

[26]  A. V. Belozerov,et al.  Chemical identification and properties of element 112 , 2003 .

[27]  W. Seidel,et al.  Experiments to produce isotopes of superheavy elements with atomic numbers 114–116 in 48Ca ion reactions , 1978 .

[28]  Skalski,et al.  Spontaneous-fission half-lives of deformed superheavy nuclei. , 1995, Physical review. C, Nuclear physics.

[29]  W. D. Myers,et al.  NUCLEAR MASSES AND DEFORMATIONS , 1966 .

[30]  J. F. Wild,et al.  Search for Superheavy Elements in the Bombardment of Cm-248 with Ca-48 , 1977 .

[31]  S. L. Nelson,et al.  Attempt to confirm superheavy element production in the 48Ca + 238U reaction , 2005 .

[32]  Y. Oganessian.  Nuclear physics: Sizing up the heavyweights , 2001, Nature.

[33]  H. Geiger,et al.  LVII. The ranges of the α particles from various radioactive substances and a relation between range and period of transformation , 1911 .

[34]  N. Bohr,et al.  Velocity-Range Relation for Fission Fragments , 1940 .

[35]  S. Nilsson.  Prediction of SHE half-lives on the basis of a single-particle potential , 1978 .

[36]  Y. Oganessian,et al.  Synthesis of 292116 in the 248Cm + 48Ca reaction , 2001 .

[37]  A. Sobiczewski.  Review of recent SHE predictions , 1974 .

[38]  N. Holden,et al.  Spontaneous fission half-lives for ground-state nuclide (Technical report) , 2000 .

[39]  F. Hessberger,et al.  Separation of actinide-made transurania by a gas-filled magnetic separator , 1995 .

[40]  S. Hofmann.  New elements - approaching , 1998 .

[41]  J. F. Wild,et al.  Measurements of cross sections for the fusion-evaporation reactions 244 Pu ( 48 Ca ,xn ) 292-x 114 and 245 Cm ( 48 Ca ,xn ) 293-x 116 , 2004 .

[42]  M. Schädel.  The Chemistry of Transactinide Elements-Experimental Achievements and Perspectives , 2002 .

[43]  A. Sobiczewski,et al.  Ground-state properties of the heaviest nuclei analyzed in a multidimensional deformation space , 1991 .

[44]  A. P. Kabachenko,et al.  The electrostatic separator VASSILISSA Performance and experimental results , 1997 .

[45]  Ishikawa,et al.  Transition energies of mercury and ekamercury (element 112) by the relativistic coupled-cluster method. , 1995, Physical review. A, Atomic, molecular, and optical physics.

[46]  S. Goriely,et al.  Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. IV: Neutron-matter constraint , 2005 .

[47]  Intermetallic compounds of the heaviest elements: the electronic structure and bonding of dimers of element 112 and its homolog Hg , 2002 .

[48]  W. Myers,et al.  Nuclear ground state masses and deformations , 1995 .

[49]  W. Greiner,et al.  Synthesis of Fermium and Transfermium Elements Using Calcium-48 Beam , 1977 .

[50]  W. Greiner,et al.  Shell structure of superheavy nuclei , 2000 .

[51]  D. Brink,et al.  Hartree-Fock Calculations with Skyrme's Interaction. I. Spherical Nuclei , 1972 .

[52]  T. Dong,et al.  New calculations of α-decay half-lives by the Viola-Seaborg formula , 2005 .

[53]  A. P. Kabachenko,et al.  Spontaneous-fission decay properties and production cross-sections for the neutron-deficient nobelium isotopes formed in the 44, 48Ca + 204, 206, 208Pb reactions , 2003 .

[54]  W. Nazarewicz,et al.  Shell structure of the superheavy elements , 1996, nucl-th/9608020.

[55]  J. F. Wild,et al.  Transfer cross sections from reactions with /sup 254/Es as a target , 1986 .

[56]  R. Hahn,et al.  Actinide production in collisions of /sup 238/U with /sup 248/Cm , 1982 .

[57]  Niels Bohr,et al.  Scattering and Stopping of Fission Fragments , 1940 .

[58]  K. Morita,et al.  INS gas-filled recoil isotope separator , 1987 .

[59]  Y. Tsyganov,et al.  Evaporation residue collection efficiencies and position spectra of the Dubna gas-filled recoil separator , 2002 .

[60]  G. Münzenberg,et al.  The velocity filter ship, a separator of unslowed heavy ion fusion products , 1979 .

[61]  R. Smolańczuk.  Production mechanism of superheavy nuclei in cold fusion reactions , 1999 .

[62]  S. G. Thompson,et al.  Stability of superheavy nuclei and their possible occurrence in nature , 1969 .

[63]  G. Munzenberg.  REVIEW ARTICLE: Recent advances in the discovery of transuranium elements , 1988 .

[64]  A. H. Wapstra,et al.  The AME2003 atomic mass evaluation . (II). Tables, graphs and references , 2003 .

[65]  W. Greiner,et al.  Heavy elements and related new phenomena , 1999 .

[66]  J. F. Wild,et al.  Heavy element research at Dubna , 2004 .

[67]  W. Hillebrandt,et al.  The beta strength function and the astrophysical site of ther-process , 1981 .

[68]  Chemical identification of dubnium as a decay product of element 115 produced in the reaction 48Ca + 243Am , 2005 .

[69]  J. Nix,et al.  Calculation of fission barriers for heavy and superheavy nuclei. , 1972 .

[70]  A. Sobiczewski,et al.  Main deformed shells of heavy nuclei studied in a multidimensional deformation space , 1991 .

[71]  S. Goriely,et al.  Hartree-Fock mass formulas and extrapolation to new mass data , 2002 .

[72]  Yu.A. Musychka.  Single-particle potentials and the stability of superheavy nuclei , 1969 .

[73]  Y. Oganessian,et al.  Fusion-fission dynamics and perspectives of future experiments , 2003 .

[74]  B. Cohen,et al.  Fission-fragment mass separator and the nuclear charge distribution of fission fragments of a single mass , 1958 .

[75]  P. Möller,et al.  Theoretical Estimates of Spontaneous-Fission Half-Lives for Superheavy Elements Based on the Modified-Oscillator Model , 1974 .

[76]  W. Greiner,et al.  Compactness of the {sup 48}Ca induced hot fusion reactions and the magnitudes of quadrupole and hexadecapole deformations , 2006 .

[77]  A. Sobiczewski,et al.  Calculated masses of heaviest nuclei , 2003 .

[78]  Ani Aprahamian,et al.  Capture Gamma-Ray Spectroscopy and Related Topics : 12th International Symposium, Notre Dame, Indiana, 4 - 9 September 2005 , 2006 .

[79]  J. H. Landrum,et al.  Search for volatile superheavy elements from the reaction 248Cm + 48Ca , 1978 .

[80]  P. Schwerdtfeger,et al.  The chemistry of the superheavy elements. I. Pseudopotentials for 111 and 112 and relativistic coupled cluster calculations for (112)H+, (112)F2, and (112)F4 , 1997 .

[81]  Matthias Brack,et al.  Funny Hills: The Shell-Correction Approach to Nuclear Shell Effects and Its Applications to the Fission Process , 1972 .

[82]  Stéphane Goriely,et al.  A Hartree-Fock Nuclear Mass Table , 2001 .

[83]  Peter Ring,et al.  Relativistic mean field theory in finite nuclei , 1996 .

[84]  R. Eichler,et al.  On the decay properties of 269Hs and indications for the new nuclide 270Hs , 2003 .

[85]  B. Eichler,et al.  Adsorption of Radon on Ice Surfaces , 2000 .

[86]  V. Strutinsky,et al.  “Shells” in deformed nuclei , 1968 .

[87]  R. Smolańczuk.  Formation of superheavy elements in cold fusion reactions , 2001 .

[88]  Chin-Fu Tsang,et al.  On the nuclear structure and stability of heavy and superheavy elements , 1969 .

[89]  W. Greiner,et al.  Potential energy surfaces of superheavy nuclei , 1998, nucl-th/9902058.

[90]  W. Greiner,et al.  Unified consideration of deep inelastic, quasi-fission and fusion fission phenomena , 2005 .

[91]  Niels Bohr,et al.  The Mechanism of nuclear fission , 1939 .

[92]  A. Yeremin,et al.  Production and decay of269110 , 1995 .

[93]  V. Zagrebaev.  Synthesis of superheavy nuclei: Nucleon collectivization as a mechanism for compound nucleus formation , 2001 .

[94]  A. J. Pacheco,et al.  Capture reactions in the sup 40,48 Ca+ sup 197 Au and sup 40,48 Ca+ sup 208 Pb systems , 1992 .

[95]  W. Nazarewicz,et al.  Structure of Odd-N Superheavy Elements , 1999 .

[96]  Hongfei Zhang,et al.  α decay half-lives of new superheavy nuclei within a generalized liquid drop model , 2006, nucl-th/0607060.

[97]  B. Mottelson,et al.  Classification of the Nucleonic States in Deformed Nuclei , 1955 .

[98]  M. G. Mayer.  On Closed Shells in Nuclei. II , 1948 .

[99]  S. Mitsuoka,et al.  Fusion of deformed nuclei in the reactions of76Ge+150Ndand28Si+198Ptat the Coulomb barrier region , 2000 .

[100]  M. Fowler,et al.  A search for superheavy elements with half-lives between a few minutes and several hundred days, produced in the 48Ca+248Cm reaction , 1978 .

[101]  J. F. Wild,et al.  Synthesis of superheavy nuclei in 48Ca+244Pu interactions , 2000 .

[102]  G. Seaborg,et al.  Nuclear systematics of the heavy elements—II Lifetimes for alpha, beta and spontaneous fission decay , 1966 .

[103]  R. Smolańczuk.  Properties of the hypothetical spherical superheavy nuclei , 1997 .

[104]  A. Kalimov,et al.  The project of the mass separator of atomic nuclei produced in heavy ion induced reactions , 2003 .

[105]  Hans E. Suess,et al.  On the "Magic Numbers" in Nuclear Structure , 1949 .

[106]  H. Sann,et al.  Dynamics of the fusion process , 1982 .

[107]  G. Münzenberg,et al.  The discovery of the heaviest elements , 2000 .

[108]  W. Greiner,et al.  On the stability of superheavy nuclei against fission , 1969 .

[109]  A. Latina,et al.  Shell effects in fission and quasi-fission of heavy and superheavy nuclei , 2004 .

[110]  K. Pitzer.  Are elements 112, 114, and 118 relatively inert gases? , 1975 .

[111]  J. Frenkel.  On the Splitting of Heavy Nuclei by Slow Neutrons , 1939 .

[112]  S. Goriely,et al.  Nuclear mass formula with Bogolyubov-enhanced shell-quenching: application to r-process , 1996 .

[113]  S. Lobastov,et al.  Exit charge-state distributions of 242.8 MeV and 264.5 MeV 48Ca ions incident on carbon and gold foils , 2005 .

[114]  Y. Oganessian.  Synthesis and decay properties of the heaviest nuclei , 2006 .

[115]  G. Rudolph,et al.  K∗(890) production in K−p → NKπ at 16 GeV/c , 1974 .

[116]  R. Bass.  Fusion reactions: Successes and limitations of a one-dimensional description , 1980 .

[117]  Y. Tsyganov,et al.  Detection system for heavy element research: present status , 2004 .

[118]  A. Yeremin,et al.  Spontaneous fission and alpha-decay properties of neutron deficient isotopes 257−253104 and 258106 , 1997 .

[119]  T. Wada,et al.  Fluctuation-dissipation model for synthesis of superheavy elements , 1999 .

[120]  Y. Tsyganov,et al.  Measurements of cross sections and decay properties of the isotopes of elements 112, 114, and 116 produced in the fusion reactions {sup 233,238}U, {sup 242}Pu, and {sup 248}Cm+{sup 48}Ca , 2004 .

[121]  H. Gäggeler,et al.  Cold fusion reactions with 48Ca , 1989 .

[122]  R. Eichler,et al.  Thermochromatographic studies of mercury and radon on transition metal surfaces , 2005 .

[123]  R. Dressler,et al.  Decay properties of {sup 265}Sg(Z=106) and {sup 266}Sg(Z=106) , 1998 .

[124]  D. Lunney,et al.  Recent trends in the determination of nuclear masses , 2003 .

[125]  D. Schumann.  Chemical procedure applied for the identification of Rf/Db produced in the 48Ca +243Am reaction , 2005 .

[126]  A. P. Kabachenko,et al.  Second experiment at VASSILISSA separator on the synthesis of the element 112 , 2004 .

[127]  I. Zvara.  Simulation of Thermochromatographic Processes by the Monte Carlo Method , 1985 .

[128]  J. E. Lynn,et al.  The double-humped fission barrier , 1980 .

[129]  Y. Oganessian.  Reactions of synthesis of heavy nuclei: Brief summary and outlook , 2006 .

[130]  A. V. Yeremin,et al.  The new element 111 , 1995 .

[131]  J. Berger,et al.  Microscopic analysis of collective dynamics in low energy fission , 1984 .

[132]  J. F. Wild,et al.  Spontaneous fission properties of 252,254No and 256,258[104] and the disappearance of the outer fission barrier , 1994 .

[133]  A. P. Kabachenko,et al.  Search for new isotopes of element 112 by irradiation of 238U with 48Ca , 1999 .

[134]  Moody,et al.  Discovery of enhanced nuclear stability near the deformed shells N=162 and Z=108. , 1994, Physical review letters.

[135]  R. Eichler,et al.  IVO, a device for In situ Volatilization and On-line detection of products from heavy ion reactions , 2002 .

[136]  R. Eichler,et al.  Chemical investigation of hassium (element 108) , 2002, Nature.

[137]  V. Chechetkin,et al.  Nucleosynthesis in supernova outbursts and the chemical composition of the envelopes of neutron stars , 1974 .

[138]  S. Goriely,et al.  Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. III: Role of particle-number projection , 2004, nucl-th/0409006.

[139]  I. Skwira-Chalot,et al.  CALCULATIONS OF FUSION-EVAPORATION CROSS SECTIONS IN THE 48Ca + 206Pband48Ca + 208Pb REACTIONS , 2006 .

[140]  P. Armbruster.  On the Production of Heavy Elements by Cold Fusion: The Elements 106 to 109 , 1985 .

[141]  W. Nazarewicz,et al.  Shape coexistence and triaxiality in the superheavy nuclei , 2005, Nature.

[142]  A. Sobiczewski,et al.  Description of structure and properties of superheavy nuclei , 2007 .

[143]  J. Stone.  TOPICAL REVIEW: Self-consistent Hartree Fock mass formulae: a review , 2005 .

[144]  D. C. Hoffman.  Spontaneous fission properiies and lieftime systematics , 1989 .

[145]  T. Legou,et al.  Production of superheavy elements at GANIL , 2000 .

[146]  J. Berger,et al.  Superheavy, hyperheavy and bubble nuclei , 2001 .

[147]  Y. Oganessian,et al.  Heavy ion physics : VI International School-Seminar, Dubna, Russia, 22-27 September 1997 , 1998 .

[148]  Attempts to chemically investigate element 112 , 2005 .

[149]  R. Janik,et al.  The new element 112 , 1996 .

[150]  Microscopic description of superheavy nuclei , 2005, nucl-th/0505067.

[151]  A. P. Kabachenko,et al.  Synthesis of nuclei of the superheavy element 114 in reactions induced by 48Ca , 1999, Nature.

[152]  J. F. Wild,et al.  MEASUREMENTS OF CROSS SECTIONS FOR THE FUSION-EVAPORATION REACTIONS 204,206,207,208PB+48CA and 207PB+34S: DECAY PROPERTIES OF THE EVEN-EVEN NUCLIDES 238CF AND 250NO , 2002 .

[153]  M. Gupta,et al.  Nuclear Data Sheets for A = 266–294* , 2005 .

[154]  Y. Lobanov,et al.  On the synthesis of element 105 , 1971 .

[155]  Y. Oganessian,et al.  Experimental Studies of the Formation and Radioactive Decay of Isotopes with Z = 104—109 , 1984 .

[156]  J. Dufour,et al.  Sassy, a gas-filled magnetic separator for the study of fusion reaction products , 1988 .