Steven W. Yates

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Education: 
B.S., University of Missouri at Columbia, 1968
Ph.D., Purdue University, 1973
Graduate Training: 
Nuclear Chemistry and Radiochemistry
Research: 

For many years it has been recognized that nuclei in certain mass regions exhibit stable deformations, while those in other regions are essentially spherical. The shell model, an independent-particle model, has been used to explain the properties of spherical nuclei by assigning orbitals to each of the neutrons and protons of the nucleus. These orbitals are then filled in order of increasing energy, similar to the "aufbau" process in atoms. With this approach, it is possible to understand the exceptional stability of nuclei containing closed shells (or magic numbers), i.e., nuclei composed of 2, 8, 20, 28, 50, 82, and 126 neutrons or protons. In nuclei at or near closed shells, we are examining multiphonon vibrational excitations of quadrupole and octupole types.

Away from these closed shells, collective nuclear motions dominate over independent-particle modes. The best evidence for collective excitations is the rotational nuclear level structure observed for nuclei of the rare earth and actinide regions. Sequences of low-lying states closely obeying the quantum relationship for a rigid rotor occur and are reminiscent of the rotational levels known for diatomic molecules. For such open-shell nuclei, ample evidence has long been available to confirm that these nuclei have an intrinsic deformed shape. In measurements on deformed nuclei, we have sought to identify two-phonon states, to characterize "scissors mode" and "mixed-symmetry" excitations in which the neutrons and protons oscillate independently, and to search for other exotic modes.

In addition to searching for new degrees of freedom in nuclei, we have focussed on the complex transition between deformed and spherical shapes in our studies at the Accelerator Laboratory at the University of Kentucky. We have extensively utilized the inelastic neutron scattering (INS) reaction and gamma-ray emission spectroscopy to examine many nuclei. INS, coupled with detection of the de-exciting gamma rays, is distinctly superior to other nuclear reactions for the study of low-lying, low-spin nuclear states. With this method, we can obtain excellent sensitivity for observing weakly excited states, and the INS reaction is not restricted by spin and parity selection rules. We have developed methods for measuring short nuclear lifetimes with the Doppler-shift attenuation method, and gamma-gamma coincidence measurements are now performed routinely. We are currently exploiting these unique advantages to examine a variety of structural features of nuclei and to search for new, exotic nuclear modes.

 Awards and Honors

  • 1972-1973 Procter and Gamble Fellow
  • 1981 University of Kentucky (UK) Research Foundation Award
  • 1983 Student Affiliates of the American Chemical Society (SAACS) Teacher of the Year
  • 1985 Chairman, Lexington Section of the American Chemical Society (ACS)
  • 1987-1989 Councilor, Lexington Section of ACS
  • 1992-1993 University Research Professor, UK
  • 1992 Chancellor's Award for Outstanding Teaching, UK
  • 1992 Chairman, Division of Nuclear Chemistry and Technology, ACS
  • 1993-1994 Distinguished Professor of the College of Arts and Sciences, UK
  • 1994 William B. Sturgill Award for Outstanding Contributions to Graduate Education, UK
  • 1995-2003 Councilor, Division of Nuclear Chemistry and Technology, ACS
  • 2002 Fellow of the International Union of Pure and Applied Chemistry (IUPAC)
  • 2004-present, Professor of Physics and Astronomy, UK
  • 2005-2009 Chair, Department of Chemistry, UK
  • 2006 Glenn T. Seaborg Award for Nuclear Chemistry, ACS
  • 2008-2013 Councilor, Division of Nuclear Chemistry and Technology, ACS
  • 2008-present, Arts and Sciences Distinguished Professor, UK
  • 2009 Fellow of the American Chemical Society, Member of the Inaugural Class of ACS Fellows
  • 2010 Award in Recognition of Fifteen Years of Service on the Council of the American Chemical Society
  • 2012 Southeastern Conference Academic Consortium (SECAC) Faculty Achievement Award, Inaugural UK Representative

Visiting Appointments

  • NSF Undergraduate Research Fellow, Lawrence Berkeley Laboratory, summer 1967
  • Visiting Scientist, Oak Ridge National Laboratory, summer 1976
  • Gastwissenschaftler, Kernforschungsanlage Juelich, Germany, 1981-1982
  • Participating Guest, Lawrence Livermore National Laboratory, 1984-2005
  • Visiting Scientist, Lawrence Livermore National Laboratory, 1989-1990
  • Guest Scientist and Visiting Professor, Los Alamos National Laboratory, 1997, 1998
  • Visiting Scientist, TRIUMF, University of British Columbia, Canada, 2009-2010 

                                                                                                                                                                                                                                    

Selected Publications: 

Publications from INSPIRE-HEP database

  • E. Elhami, J. N. Orce, S. Mukhopadhyay, S. N. Choudry, M. Scheck, M. T. McEllistrem, and S. W. Yates, “Anomalous Behavior of the 2+ Mixed-Symmetry State in 94Zr”, Phys. Rev. C 75, 011301(R), 2007.
  • J. N. Orce, C. Fransen, A. Linnemann, C. J. McKay, S. R. Lesher, N. Pietralla, V. Werner, G. Friessner, C. Kohstall, D. Mücher, H.H. Pitz, M. Scheck, C. Scholl, F. Stedile, N. Warr, S. Walter, P. von Brentano, U. Kneissl, M. T. McEllistrem, and S. W. Yates, “Lifetime measurements in 93Nb from photon and inelastic neutron scattering”, Phys. Rev. C 75, 014303 (2007).
  • S. R. Lesher, C. J. McKay, M. Mynk, D. Bandyopadhyay, N. Boukharouba, C. Fransen, J. N. Orce, M. T. McEllistrem, and S. W. Yates, “Study of the Low-Spin Structure of 96Mo with the (n,n'g) Reaction”, Phys. Rev. C 75, 034318 (2007).
  • M. Scheck, P. von Brentano, C. Fransen, U. Kneissl, C. Kohstall, A. Linnemann, D. Mücher, N. Pietralla, H. H. Pitz, C. Scholl. F. Stedile, S. Walter, V. Werner, and S. W. Yates, “Dipole Strength Distributions of the Stable odd-mass N = 82 isotones 139La and 141Pr”, Phys. Rev. C 75, 044313 (2007).
  • P. E. Garrett, K. L. Green, H. Lehmann, J. Jolie, C. A. McGrath, M. Yeh, and S. W. Yates, “Properties of 112Cd from the (n,n'g) Reaction: Lifetimes and Transition Rates”, Phys. Rev. C 75, 054310 (2007).
  • J. N. Orce, S. N. Choudry, B. Crider, E. Elhami, S. Mukhopadhyay, M. Scheck, M. T. McEllistrem, and S. W. Yates, “21+ --> 01+ Transition Strengths in the Sn Nuclei”, Phys. Rev. C 76, 021302(R) (2007); Phys. Rev. C 77, 029902(E) (2008).
  • S. R. Lesher, J. N. Orce, Z. Ammar, C. D. Hannant, M. Merrick N. Warr, T. B. Brown, N. Boukharouba, C. Fransen, M. Scheck, M. T. McEllistrem, and S. W. Yates, “Study of 0+ Excitations in 158Gd with the (n,n'g) Reaction”, Phys. Rev. C 76, 034318 (2007).
  • D. Bandyopadhyay, S. R. Lesher, C. Fransen, N. Boukharouba, P. E. Garrett, K. L. Green, M. T. McEllistrem, and S. W. Yates, “An Investigation of Phonon Excitations in 114Cd with the (n,n'g) Reaction”, Phys. Rev. C 76, 054308 (2007).
  • I. Ahmad, F. G. Kondev, Z. M. Koenig, W. C. McHarris, and S. W. Yates, “Two-quasiparticle states in 250Bk studied by Decay Scheme and Transfer Reaction Spectroscopy”, Phys. Rev. C 77, (2008).
  • J. N. Orce, S. N. Choudry, B. Crider, E. Elhami, S. Mukhopadhyay, M. Scheck, M. T. McEllistrem, and S. W. Yates, “21+ --> 01+ Transition Strengths in the Sn Nuclei,” Phys. Rev. C 76, 021302(R) (2007), Phys. Rev. C 77, 029902(E) (2008).
  • J. N. Orce, B. Crider, S. Mukhopadhyay, E. Peters, E. Elhami, M. Scheck, B. Singh, M. T. McEllistrem, and S. W. Yates, Determination of the 21+ --> 01+ Transition Strengths in 58Ni and 60Ni,” Phys. Rev. C 77, 064301 (2008).
  • W. D. Kulp, J. L. Wood, P. E. Garrett, C. Y. Wu, D. Cline, J. M. Allmond, D. Bandyopadhyay, D. Dashdorj, S. N. Choudry, A. B. Hayes, H. Hua, M. G. Mynk, M. T. McEllistrem, C. J. McKay, J. N. Orce, R. Teng, and S. W. Yates, “Search for Intrinsic Collective Excitations in 152Sm,” Phys. Rev. C 77, 061301(R) (2008).
  • M. Scheck, S. N. Choudry, E. Elhami, M. T. McEllistrem, S. Mukhopodyay, J. N. Orce, and S. W. Yates, “Pauli blocking in the  low-lying, low-spin states of 141Pr,” Phys. Rev. C 78, 034302 (2008).
  • S. Mukhopadhyay, M. Scheck, B. Crider, S. N. Choudry, E. Elhami, E. Peters, M. T. McEllistrem, J. N. Orce, and S. W. Yates, “Multiphonon states in 136Ba”, Phys. Rev. C 78, 034317 (2008).
  • E. Elhami, J. N. Orce, M. Scheck, S. Mukhopadhyay, S. N. Choudry, M. T. McEllistrem, S. W. Yates, C. Angell, M. Boswell, B. Fallin, C. R. Howell, A. Hutcheson, H. J. Karwowski, J. H. Kelly, Y. Parpottas, A. P. Tonchev, and W. Tornow, “Experimental study of the low-lying structure of  94Zr with the (n,n'g) reaction,” Phys. Rev. C 78, 064303 (2008).
  • S. F. Hicks, J. R. Vanhoy, and S. W. Yates, “Fragmentation of Mixed-Symmetry Excitations in Stable Even-Even Te Nuclei,” Phys. Rev. C 78, 054320 (2008).
  • S. W. Yates, "Probing Nuclear Structure with Fast Neutrons," AIP Conference Proceedings (2009) 1090  (Capture Gamma-Ray Spectroscopy and Related Topics), 517-523.
  • P. E. Garrett, W. D. Kulp, J. L. Wood, D. Bandyopadhyay, S. Choudry, D. Dashdorj, S. R. Lesher, M. T. McEllistrem, M. Mynk, J. N. Orce, and S. W. Yates, "New Features of Shape Coexistence in 152Sm, Phys. Rev. Lett. 103, 062501 (2009).
  • K. L. Green, P. E. Garrett, R. A. E. Austin, G. C. Ball, D. S. Bandyopadhyay, S. Colosimo, D. Cross, G. A. Demand, G. F. Grinyer, G. Hackman, W. D. Kulp, K. G. Leach, A. C. Morton, C. J. Pearson, A. A. Phillips, M. A. Schumaker, C. E. Svensson, J. Wong, J. L. Wood, and S. W. Yates, "Degeneracy at 1871 keV in 112Cd and Implications for Neutrinoless Double Electron Capture," Phys. Rev. C 80, 032502(R), 2009.
  • L. Caballero, B. Rubio, P. Kleinheinz, S. W. Yates, A. Algora, A. Dewald, A. Fitzler, A. Gadea, J. Jolie, R. Julin, A. Linnemann, S. Lunardi, R. Menegazzo, O. Möller, E. Nácher, M. Piiparinen, and J. Blomqvist, “Two-Phonon Octupole Excitation in 146Gd,” Phys. Rev. C 81, 031301(R), (2010).
  • M. Scheck, P. A. Butler, C. Fransen, V. Werner, and S. W. Yates, “Strong M1 Components in 3- --> 3- Transitions in Nearly Spherical Nuclei: Evidence for isovector-octupole excitations,” Phys. Rev. C 81, 064305 (2010).
  • J. N. Orce, J. D. Holt, A. Linnemann, C. J. McKay, S. R. Lesher, C. Fransen, V. Werner, T. T. S. Kuo, M. T. McEllistrem, N. Pietralla, and S. W. Yates, “Fermionic-Bosonic Couplings in a Weakly-Deformed Odd-Mass Nucleus, 93Nb ” Phys. Rev. C 82, 044317 (2010) 11 pages.
  • A. Chakraborty, J.  N. Orce, S. F. Ashley, B. A. Brown, B. Crider, E. Elhami, M. T. McEllistrem, S. Mukhopadhyay, E. Peters, and S. W. Yates, “Status of vibrational structure in 62Ni,” Phys. Rev. C 83, 034316 (2011).
  • P. E. Garrett, K. L. Green, R. A. E. Austin, G. C. Ball, D. S. Bandyopadhyay, S. Colosimo, D. C. Cross, G. A. Demand, G. F. Grinyer, G. Hackman, W. D. Kulp, K. G. Leach, A. C. Morton, C. J. Pearson, A. A. Phillips, M. A. Schumaker, C. E. Svensson, J. Wong, J. L. Wood, and S. W. Yates, Acta Physica Polonica B 42, 799 (2011). 
  • S. W. Yates, “On quadrupole vibrations in nearly spherical nuclei,” Proceedings of the Rutherford Centennial Conference on Nuclear Physics 2011, Journal of Physics: Conference Series 381, 012048 (2012).
  • N. Cooper, F. Reichel, V. Werner, L. Bettermann, B. Alikhani, S. Aslanidou, C. Bauer, L. Coquard, M. Fritzsche, Y. Fritzsche, J. Glorius, P.M. Goddard, T. Mӧller, N. Pietralla, M. Reese, C. Romig, D. Savran, L. Schnorrenberger, F. Siebenhühner, V. V. Simon, K. Sonnabend, M.K. Smith, C. Walz, S. W. Yates, O. Yevetska, and M. Zweidinger, “Photoresponse of 76Se below 9 MeV,” Phys. Rev. C 86, 034313 (2012).
  • P.E. Garrett, J. Bangay, A. Diaz-Varela, F. Corminboeuf, G.C. Ball, G.A. Demand, D.S. Cross, P. Finlay, A. Garnsworthy, L. Genilloud, K.L. Green, G. Hackman, C.D. Hannant, B. Jigmeddorj, J. Jolie, W.D. Kulp, K.G. Leach, J.N. Orce, A.A. Phillips, A.J. Radich, E.T. Rand, M.A. Schumaker, C.E. Svensson, C. Sumithrarachchi, S. Triambak, N. Warr, J. Wong, J.L. Wood, and S.W. Yates, ‘Detailed spectroscopy of 110Cd: Evidence for weak mixing and the emergence of γ-soft behavior,” Phys. Rev. C 86, 044304 (2012).
  • S. F. Hicks, J. C. Boehringer, N. Boukharouba, C. Fransen, S. Lesher, J. M. Mueller, J. R. Vanhoy, and S. W. Yates, “Collective and few-particle excitations in 128Te,” Phys. Rev. C 86, 054308 (2012) 21 pages.
  • A. Chakraborty, F. M. Prados-Estévez, S. N. Choudry, B. P. Crider, P. E. Garrett, W. D. Kulp, A. Kumar, M. T. McEllistrem, S. Mukhopadhyay, M. G. Mynk, J. N. Orce, E. E. Peters, J. L. Wood, and S. W. Yates, “New decay pattern of negative-parity states at N = 90,” Phys. Rev. C 86, 065314 (2012) 6 pages.
  • A. Chakraborty, E.E. Peters, B.P. Crider, C. Andreoiu, P.C. Bender, D.S. Cross, G.A. Demand, A.B. Garnsworthy, P.E. Garrett, G. Hackman, B. Hadinia, S. Ketelhut, Ajay Kumar, K.G. Leach, M.T. McEllistrem, J. Pore, F.M. Prados-Estévez, E.T. Rand, B. Singh, E.R. Tardiff, Z.-M. Wang, J.L. Wood, and S.W. Yates, “Collective Structure in 94Zr and Subshell Effects in Shape Coexistence,” Phys. Rev. Lett. 110, 022504 (2013) 4 pages.
  • V. Bildstein, P.E. Garrett, J. Wong, D. Bandyopadhyay, J. Bangay, L. Bianco, B. Hadinia, K.G. Leach, C. Sumithrarachchi, S.F. Ashley, B.P. Crider, M.T. McEllistrem, E.E. Peters, F.M. Prados-Estévez, S.W. Yates, and J.R. Vanhoy, “Comparison of deuterated and normal scintillators for fast-neutron detection,” Nucl. Instrum. Meth. Phys. Res. A729, 188-197 (2013).
  • E.E. Peters, A. Chakraborty, B.P. Crider, B.H. Davis, M.K. Gnanamani, M.T. McEllistrem, F.M. Prados-Estévez, J.R. Vanhoy, and S.W. Yates,  “Level lifetimes in the stable Zr nuclei: Effects of chemical properties in Doppler-shift measurements,” Phys. Rev. C 88, 024317 (2013), 10 pages.

 

 

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