John R. Clem

17 Physics Hall
Iowa State University
Ames, IA 50011
Phone 515-294-4223

Research Interests

The goal of my current research program has been to make significant theoretical advances con cerning the electrodynamic behavior of current-carrying superconductors subjected to mag netic fields. Recently I have been giving greatest attention to the high-temperature superconduc tors, first discovered in 1986. Problems that I am particularly interested in include flux pinning, critical currents, flux flow, ac losses, noise, spiral and intersecting vortices, instabilities, surface and interface effects, proximity effects, and two- and three-dimensional arrays of Josephson junctions. Although my focus is generally on the solution of fundamental problems, I always have been strongly motivated by the fact that a solidly based theoretical understanding of the above interrelated subjects is needed to make the most effective use of superconductors in various applications, both large-scale (e.g., wire and tapes for high-field magnets and power transmission lines) and small-scale (e.g., filters, resonators, and Josephson devices for use in sensitive detectors and logic devices.)

        Project Affiliations:

(Chronologically most recent on top)Education

  • Ph.D. Physics, University of Illinois, 1965
  • M.S. Physics, University of Illinois, 1962
  • B.S. Engineering Physics, University of Illinois, 1960

(Chronologically most recent on top)Professional Appointments

  • 2001 - 2010 Contract Associate (1/4 time), Ames Laboratory
  • 1992 - 1993 Visiting Scientist, Electric Power Research Institute, Palo Alto, CA
  • 1992 - 1993 Visiting Professor of Applied Physics, Stanford University, Stanford, CA
  • 1985 - 1986 Visiting Scientist, IBM Thomas J. Watson Research Center, Yorktown Heights, NY
  • 1982 - 1985 Chairman, Department of Physics, Iowa State University
  • 1975 - 2001 Senior Physicist, Ames Laboratory
  • 1974 - 1975 Fulbright Research Fellow, Kernforschungsanlage Jülich, Germany
  • 1971 - 2010 Various appointments as Consultant at Los Alamos National Laboratory, Argonne National Laboratory, Brookhaven National Laboratory, IBM Thomas J. Watson Research Center, Allied-Signal Aerospace Company, Underground Systems, Inc., American Superconductor Corporation, Pirelli Cable Corporation
  • 1970 - 1975 Physicist, Ames Laboratory
  • 1967 - 1970 Associate Physicist, Ames Laboratory
  • 1966 - 1967 Visiting Research Fellow, Technical University, Munich, Germany
  • 1965 - 1966 Research Associate, University of Maryland

(Chronologically most recent on top)Honors & Awards

  • 2010 American Physical Society Outstanding Referee
  • 2004 Fellow, Institute of Physics, London
  • 1999 Most Valuable Instructor (teaching award from graduate students in the Iowa State University Department of Physics and Astronomy, 2000)
  • 1997 Phi Kappa Phi Centennial Medalist, Iowa State University Chapter of Phi Kappa Phi
  • 1991 Teaching Award from Graduate Students in the Iowa State University Department of Physics and Astronomy
  • 1990 For contributions to the superconductivity community, Applied Superconductivity Conference, Inc.
  • 1988 DOE Annual Award for Sustained Outstanding Research in Solid State Physics
  • American Association of University Professors
  • 1982 Fellow, American Physical Society

(Chronologically most recent on top)Publications with the Ames Laboratory

Clem J R; Weigand M; Durrell J H; Campbell A M . 2011. Theory and experiment testing flux-line cutting physics. Superconductor Science & Technology. 24:062002. abstract
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Jones W A; Barnes P N; Mullins M J; Baca F J; Emergo R L S; Wu J; Haugan T J; Clem J R . 2010. Impact of edge-barrier pinning in superconducting thin films. Applied Physics Letters. 97:262503. abstract
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Connolly M R; Bending S J; Milosevic M V; Clem J R; Tamegai T . 2010. Continuum versus discrete flux behaviour in large mesoscopic Bi2Sr2CaCu2O8+delta disks. Physica C-Superconductivity and Its Applications. 470:S896-S897. abstract
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Clem J R . 2010. Corbino-geometry Josephson weak links in thin superconducting films. Physical Review B. 82:174515. abstract
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Curran P J; Clem J R; Bending S J; Tsuchiya Y; Tamegai T . 2010. Geometry-dependent penetration fields in superconducting Bi2Sr2CaCu2O8+delta platelets. Physical Review B. 82:134501. abstract
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Clem J R . 2010. Josephson junctions in thin and narrow rectangular superconducting strips. Physical Review B. 81:144515. abstract
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Clem J R; Malozemoff A P . 2010. Theory of ac loss in power transmission cables with second generation high temperature superconductor wires. Superconductor Science & Technology. 23:034014. abstract
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Sanchez A; Navau C; Del-Valle N; Chen D X; Clem J R . 2010. Self-fields in thin superconducting tapes: Implications for the thickness effect in coated conductors. Applied Physics Letters. 96:-. abstract
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Sadleir J E; Smith S J; Bandler S R; Chervenak J A; Clem J R . 2010. Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors. Physical Review Letters. 104:047003. abstract
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Clem J R . 2009. Field and current distributions and ac losses in superconducting strips. Physical Review B. 80:184517. abstract
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