Walter D. Knight

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Walter David Knight (born October 14, 1919 in New York City , † June 28, 2000 in Marlborough (New Hampshire) ) was an American physicist.

Life

Knight, the son of a leading Presbyterian clergyman, grew up in New York City and in the Marlborough, New Hampshire countryside, where his family came from. He graduated from Middlebury College in Vermont with a bachelor's degree in 1941, was a radar officer in the Navy during World War II and continued his studies at Duke University , where he received his PhD in 1950, while he was an assistant professor at Trinity College, Hartford. From 1950 he was at the University of California, Berkeley , where he became a professor and from 1967 to 1972 dean of the College of Letters and Science. He had previously been Associate Dean and led faculty protests against the random selection of qualified undergraduates for further study. In 1990 he retired.

plant

The Knight Shift is named after him, a frequency shift in NMR in metals and a consequence of the paramagnetism of the conduction electrons. The discovery came about while working on his dissertation. Charles Townes was the informal advisor on his dissertation, for which he carried out experiments at Brookhaven National Laboratory . During the subsequent investigation of NMR shifts in various (non-cubic) metals, he was the first to discover nuclear quadrupole resonance in a metal ( gallium ). With the help of the Knight shift, he was also able to predict the BCS theory of superconductivity (decrease in spin paramagnetism and the Knight shift of electrons as the temperature approaches the superconductivity transition due to the increasing pairing).

From the 1960s he also investigated nanoclusters of metals with Knight's shift and (following a proposal with his student P. Yee 1975) with molecular beams of clusters. In the 1980s, shell effects (magic numbers) such as those of atoms and atomic nuclei were also demonstrated. Part of the work was done with his doctoral student Walter de Heer .

Memberships and honors

In 1955 he became a Sloan Research Fellow . He was a Fellow of the American Physical Society , the American Association for the Advancement of Science and, since 1985, a member of both the National Academy of Sciences and the American Academy of Arts and Sciences . He received the Berkeley Citation (the university's highest honor) in 1990 and was an honorary doctor of Middlebury College and EPFL in Lausanne.

He is co-author (with Charles Kittel and Malvin Ruderman , Burton J. Moyer, and A. Carl Helmholz) on the Berkeley Physics course in mechanics.

Fonts (selection)

Except for the works cited in the footnotes.

  • Electron paramagnetism and nuclear magnetic resonance in metals, Solid State Physics, Volume 2, 1956, p. 93
  • Knight, G. Androes, R. Hammond, Nuclear magnetic resonance in a superconductor, Phys. Rev., Volume 104, 1956, p. 852
  • Knight, Androes, Nuclear magnetic resonance in superconducting tin, Phys. Rev., Vol. 121, 1961, p. 779

literature

Web links

Individual evidence

  1. ^ Knight, Nuclear Magnetic Resonance Shift in Metals, Physical Review, Volume 76, 1949, pp. 1259-1260
  2. ↑ Knight, R. Hewitt, M. Pomerantz, Nuclear quadrupole resonance in metals, Phys. Rev., Volume 104, 1956, p. 271
  3. ↑ Knight, Yee, Quantum size effects in copper: NMR in small particles, Phys. Rev. B, Vol. 11, 1975, p. 3261
  4. ↑ Knight, Clemenger, de Heer, Saunders, Chou, Cohen, Electronic Shell Structure and Abundances of Sodium Clusters, Phys. Rev. Lett., Vol. 52, 1984, p. 2141, Abstract
  5. ↑ Knight, de Heer, Saunders, Clemenger: Photoionization and shell structure of potassium clusters, Phys. Rev. B, Vol. 32, 1985, p. 1366
  6. ↑ Knight, de Heer, MY Chou, ML Cohen, Electronic shell structure and metal clusters, Solid State Physics, Volume 40, 1987, p. 93
personal data
SURNAME Knight, Walter D.
ALTERNATIVE NAMES Knight, Walter David (full name)
BRIEF DESCRIPTION American physicist
DATE OF BIRTH October 14, 1919
PLACE OF BIRTH New York City
DATE OF DEATH June 28, 2000
Place of death Marlborough, New Hampshire