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Effect of power line interference on microphone calibration measurements made at or near harmonics of the power line frequency
No full textThe electrical measurements required during the primary calibrations of laboratory standard microphones by the reciprocity method can be influenced by power line interference. Because of this influence, the protocols of international inter-laboratory key comparisons of microphone calibrations usually have not included measurements at power line frequencies. Such interference has been observed in microphone output voltage measurements made with a microphone pressure reciprocity calibration system under development at NIST. This system was configured for a particular type of standard microphone in such a way that measurements of relatively small signal levels, which are more susceptible to the effect of power line interference, were required. This effect was investigated by acquiring microphone output voltage measurement data with the power line frequency adjusted to move the frequency of the interference relative to the center frequency of the measurement system passband. These data showed that the effect of power line interference for this system configuration can be more than one percent at test frequencies harmonically related to the power line frequency. These data also showed that adjusting the power line frequency to separate the interference and test frequencies by as little as 1.0 Hz can reduce the effect of the interference by at least an order of magnitude. Adjustment of the power line frequency could enable accurate measurements at test frequencies that otherwise might be avoided
Extracting electron densities in N-type GaAs from Raman spectra: Theory
No full textIn this paper, we present the theory for calculating Raman line shapes as functions of the Fermi energy and finite temperatures in zinc blende, n- type GaAs for donor densities between 10(16) cm(-3) and 10(19) cm(-3). Compared to other theories, this theory is unique in two respects: 1) the many- body effects are treated self- consistently and 2) the theory is valid at room temperature for arbitrary values of the ratio R = (Q(2)/a), where Q is the magnitude of the normalized wave vector and a is the normalized frequency used in the Raman measurements. These calculations solve the charge neutrality equation self- consistently for a two- band model of GaAs at 300 K that includes the effects of high carrier concentrations and dopant densities on the perturbed densities of states used to calculate the Fermi energy as a function of temperature. The results are then applied to obtain the carrier concentrations from Fermi energies in the context of line shapes in Raman spectra due to the coupling between longitudinal optical phonons and plasmons. Raman measurements have been proposed as a non- destructive method for wafer acceptance tests of carrier density in semiconductor epilayers. The interpretation of Raman spectra to determine the majority electron density in ntype semiconductors requires an interdisciplinary effort involving experiments, theory, and computer- based simulations and visualizations of the theoretical calculations
Optical frequency metrology of an iodine-stabilized He-Ne laser using the frequency comb of a quantum-interference-stabilized mode-locked laser
No full textWe perform optical frequency metrology of an iodine-stabilized He-Ne laser using a mode-locked Ti: sapphire laser frequency comb that is stabilized using quantum interference of photocurrents in a semiconductor. Using this technique, we demonstrate carrier-envelope offset frequency fluctuations of less than 5 mHz using a 1 s gate time. With the resulting stable frequency comb, we measure the optical frequency of the iodine transition [I-127(2) R(127) 11-5 i component] to be 473 612 214 712.96 +/- 0.66 kHz, well within the uncertainty of the CIPM recommended value. The stability of the quantum interference technique is high enough such that it does not limit the measurements
He-4 thermophysical properties: New ab initio calculations
No full textSince 2000, atomic physicists have reduced the uncertainty of the helium-helium "ab initio" potential; for example, from approximately 0.6% to 0.1% at 4 bohr, and from 0.8% to 0.1% at 5.6 bohr. These results led us to: ( 1) construct a new interatomic potential phi(07), ( 2) recalculate values of the second virial coefficient, the viscosity, and the thermal conductivity of He-4 from 1 K to 10,000 K, and ( 3), analyze the uncertainties of the thermophysical properties that propagate from the uncertainty of phi(07) and from the Born-Oppenheimer approximation of the electron-nucleon quantum mechanical system. We correct minor errors in a previous publication [ J. J. Hurly and M. R. Moldover, J. Res. Nat. Inst. Standards Technol. 105, 667 ( 2000)] and compare our results with selected data published after 2000. The ab initio results tabulated here can serve as standards for the measurement of thermophysical properties
John W. Cahn
No full textJOHN W. CAHN
Inducted: 2007
Citation:
For the application of thermodynamic, crystallographic and kinetic principles to a wide range of materials-science problems in metals and ceramics including: solidification, solid state phase transformations, stress effects, capillary phenomena and the paradigm-breaking discovery of quasicrystals, metallic phases with long range orientational order but no translational symmetry.
Tenure: 1977-2006
Birth: 1928, Cologne, Germany
Education:
University of Michigan, Ann Arbor, BS (Chemistry), 1949
University of California, Berkeley, PhD (Physical Chemistry), 1953
Positions held:
Scientist, Center for Materials Science, 1977 - 1984
Senior NIST Fellow (Metallurgist), Materials Science and Engineering Laboratory, 1984 - 2006
NIST Scientist Emeritus, 2006-
Honors:
Bower Prize, Franklin Institute (2002)
Emil Heyn Medal, German Metallurgical Society (2001)
National Medal of Science (1999)
Bakhuis Roozeboom Lecturer and Gold Medal, Netherlands Academy of Science (1999)
Member, National Academy of Engineering (1998)
Harvey Prize, Israel Institute of Technology (1995)
Rockwell Medal; Hall of Fame for Engineering, Science and Technology (1994)
Michelson and Morley Prize, Case-Western University (1991)
Stratton Award, National Bureau of Standards (1986)
US Department of Commerce Gold Medal, (1984)
Fellow, Japan Society for the Promotion of Science (1981)
Fellow, American Academy of Arts and Sciences (1974)
Member, National Academy of Sciences (1973)
Honorary doctorates from Northwestern University and Evry University
Memberships:
Metallurgical Society of the American Institute of Mining, Metallurgical, and Petroleum Engineers
Fellow, Minerals, Metals, & Materials Society, and American Society for Metals, International
Publications:
Approximately 250 publications:
Cahn, J.W., "Thermodynamics of Solid and Fluid Surfaces," in Segregation to Interfaces, ASM Seminar Series, 3-23, (1978).
Allen, S.M. and Cahn, J.W., "A Microscopic Theory for Antiphase Boundary Motion and Its Application to Antiphase Domain Coarsening," Acta Metallurgica 27, 1085-1095 (1979).
Kikuchi, R. and Cahn, J.W., "Theory of Interphase and Antiphase Boundaries in FCC Alloys," Acta Metallurgica 27, 1337 (1979).
Moldover, M.R. and Cahn, J.W., “Interface Phase-Transition - Complete to Partial Wetting,” Science 207 (4435): 1073-1075 (1980).
Shechtman, D., Blech, I., Gratias, D., and Cahn, J.W., “Metallic Phase with Long-Range Orientational Order and No Translational Symmetry,” Physical Review Letters 53 (20): 1951-1953 (1984).
Larche, F.C. and Cahn, J.W., “The Interactions of Composition and Stress in Crystalline Solids,” Acta Metallurgica 33 (3): 331-357 (1985)
Howard Baum
No full textHOWARD BAUMInducted: 2007
Citation:
For developing and implementing widely applied analytical models and numerical tools for understanding and mitigating fire phenomena. These methods were major contributors to performing diverse investigations such as the World Trade Center collapse, containership fire safety standards and in the cleanup of marine oil spills.
Tenure: 1975-2006
Birth: 3 April 1936, New York City, New York
Education:
Polytechnic University, New York City, BS (Aeronautical Engineering), 1957
Polytechnic University, NYC, MS (Applied Mathematics), 1959
Harvard University, Cambridge, PhD (Applied Mathematics), 1964
Positions held:
Research Physicist, Center for Fire Research, 1975-1983
NIST Fellow, Building and Fire Research Laboratory, 1983-2006
NIST Scientist Emeritus, 2006-
Honors:
U.S. National Academy of Engineering (2000)
U.S. Department of Commerce Gold Medals (1985 and 2005) and Silver Medal (1981)
Emmons Lectureship Award for Distinguished Achievement in Fire Safety Science, International Association for Fire Safety Science (2005)
Arthur B. Guise Medal by the Society of Fire Protection Engineers (1999)
Fellow and Chartered Physicist, Institute of Physics (1999)
Phillip Thomas Medal of Excellence, International Association for Fire Safety Science (1991 and 1999)
Japan Society Award for Promotion of Science Fellowship (1994)
Russell Severance Springer Visiting Professor, University of California, Berkeley (1985)
Distinguished Paper Award, Thirty-first International Symposium on Combustion (2006)
Memberships:
Combustion Institute
International Association for Fire Safety
Institute of Physics
Sigma Xi
Society for Industrial & Applied Mathematics
Publications:
More than 170 publications, including:
Rehm, R.G. and Baum, H.R., "The Equations of Motion for Thermally Driven, Buoyant Flows", J. Research Nat. Bur. Stds,. 83, pp. 297-308 (1978).
Baum, H.R. and Rehm, R.G., "Calculations of Three Dimensional Buoyant Plumes in Enclosures", Combustion Science and Technology, 40, pp. 55-77 (1984).
Baum, H.R. and Rockett. J.A., "Analysis of the Forced Ventilation in Containership Holds", J. Fluid Mech., 142, pp. 309-342 (1984).
Baum, H.R., Ezekoye, O.A., McGrattan, K.B., and Rehm, R.G., "Mathematical Modeling and Computer Simulation of Fire Phenomena", Theoretical and Computational Fluid Dynamics, 6, pp. 125-139 (1994).
McGrattan, K.B., Baum, H.R., and Rehm, R.G., "Large Eddy Simulations of Smoke Movement", Fire Safety Journal, 30, pp. 161-178 (1998).
Baum, H.R. and Atreya, A. "A Model of Transport of Fuel Gases in a Charring Solid and its Application to Opposed-Flow Flame Spread'', Proc. Combustion Institute, 31, pp. 2633-2641 (2007)
(Transcript) Oral history interview of James E. Hill , July 27, 2007 / with David Lide, Noel Raufaste, Gregory Tassey, and Richard Wright.
No full textJames Hill recalls his career at NIST from 1972-2007. He served as the acting Deputy Director of NIST from the summer of 2006 until his retirement in April 2007
FREDERICK R. FICKETT
No full textFREDERICK R. FICKETT
Inducted: 2007
Citation:
For research excellence in electromagnetic and mechanical properties of pure metals, magnetic materials, and superconductors, and for program leadership in materials science, engineering, and solid state physics
Tenure: 1967-2003
Birth: 1937, Portland, Maine
Education:
University of New Hampshire, BS (Physics), 1960
University of Arizona, MS (Plasma Physics), 1962
Oregon State University, PhD (Solid State Physics), 1967
Positions held:
National Research Council Postdoctoral Associate, NBS, 1967-1969
Staff Physicist, Cryogenics Division, 1969–1976
Senior Staff Physicist/Project Leader, Electromagnetic Technology Division, 1976–1987
Group Leader, Magnetic Measurements, Electromagnetic Technology. Division, 1987–1995
Group Leader, Microscale Measurements, Materials Reliability Division,1995–1999
Division Chief, Magnetic Technology Division, EEEL, (concurrent) 2000–2001
Division Chief, Materials Reliability Division, MSEL, 1999–2003
Honors:
Fellow, American Physical Society
U.S. Department of Commerce Silver Medal (1985)
Board Member, International Cryogenic Materials Conference (emeritus)
Memberships:
American Physical Society and Instrument and Measurement Science Topical Group, Executive Committee
Institute of Electrical and Electronics Engineers
American Society of Testing and Materials, Committees A6, B1
Colorado Advanced Materials Institute
Colorado School of Mines Engineering Division CAB
University of Colorado Mechanical Engineering Advisory Panel
Editor, Advances in Cryogenic Engineering
Publications:
More than 85 publications including:
F.R. Fickett, “A Review of Resistive Mechanisms in Aluminum,” Cryogenics, vol. 11, pp. 349-367 (October 1971).
F.R. Fickett, “Magnetoresistance of Very Pure Polycrystalline Aluminum,” Physical Review B, vol. 3, pp. 1941-1952 (March 1971).
F.R. Fickett and A.F. Clark, “Longitudinal Magnetoresistance Anomalies,” Journal of Applied Physics, vol. 42, pp. 217-219 (January 1971).
F.R. Fickett, “Oxygen Annealing of Copper,” Materials Science and Engineering, vol. 14, pp. 199-210 (June 1974).
F.R. Fickett and D.B. Sullivan, “Magnetic Studies of Oxidized Impurities in Pure Copper Using a SQUID System,” Journal of Physics F: Metal Physics, vol. 4, pp. 900-905 (June 1974).
F.R. Fickett, “Electrical and Magnetic Properties of Internally Oxidized Copper and Dilute Copper-Iron Alloys,” Journal of Physics F: Metal Physics, vol. 12, pp. 1753-1769 (August 1982)
James E. Leiss
No full textJAMES E. LEISS
Inducted: 2007
Citation:
For converting a 100 MeV betatron to a 180 MeV electron-synchrotron for photonuclear research and the first synchrotron-light facility, SURF I; for leading the development of the 100 MeV electron linear accelerator for photonuclear research; for facilitating development of a prototype electron-microtron accelerator; and for strengthening the role of NBS as a world leader in electron and photonuclear-physics research, and electron-accelerator design and construction.
Tenure: 1954-1986
Birth: 1924, Youngstown, Ohio
Death: 2008
Education:
Case Institute of Technology, BS (Physics), 1951
University of Illinois, MS (Physics), 1951
University of Illinois, PhD (Physics), 1955
Positions held:
Physicist: High Energy Radiation Section, Radiation Physics Division, 1954-1966
Chief, Accelerator Branch, Radiation Physics Laboratory, 1966-1967
Director, Linac Radiation Division, 1968-1978
Director, Center for Radiation Research, 1978-1986
Honors:
U.S. Department of Commerce Gold Medal (1965)
Memberships:
Chairman 1975 IEEE Particle Accelerator Conference in Washington, DC
Chairman 1985 APS Division of Physics of Beams
Member, EPA Electromagnet Radiation Management Advisory Council (ERMAC)
Publications:
More than 20 publications including:
Leiss, J. E., Robinson, C.S., and Penner, S., “Photoproduction of Pi+ Mesons from Hydrogen Near Threshold”, Phys. Rev. 98 (1955).
Leiss, J.E., and Schrack,, R.A., “Nuclear Matter Distributions from Coherent Neutral Pion Production”, Rev. Mod. Phys. 30 (1958).
Penfold, A.S. and Leiss, J.E., “Analysis of Photonuclear Cross Sections”, Phys. Rev. 114(5) 1332-1337 (1959).
Leiss, J.E., “Beam Loading in Linear Accelerators” IEEE Trans. Nucl. Sci 12-566, (1965).
Leiss, J.E., Norris, N.J., and Wilson, M.A., “The Design and Performance of a Long Pulse High Current Linear Induction Accelerator at the National Bureau of Standards”, Part. Accel, 10: 223-324 (1980).
Leiss, J.E., “Impact of Accelerators on U.S. Science, Technology, and Productivity”, IEEE Trans. Nucl. Sci. 30-1353-1356 (1983)
List of Names Mentioned in Oral history interview of James E. Hill , July 27, 2007 / with David Lide, Noel Raufaste, Gregory Tassey, and Richard Wright.
No full textJames Hill recalls his career at NIST from 1972-2007. He served as the acting Deputy Director of NIST from the summer of 2006 until his retirement in April 2007