LeRoy Apker

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LeRoy Apker (born June 11, 1915 in Rochester (New York) , † 1970 ) was an American experimental solid-state physicist.

Life

Apker studied at the University of Rochester with a bachelor's degree in 1937 and a doctorate from Lee DuBridge in 1941. He then conducted research at General Electric in their research laboratories in Schenectady.

Apker investigated the photoelectric effect on semiconductors and found in 1948 with E. A. Taft and Jean Dickey (his wife) that some semiconductors behaved differently from metals with a comparable work function (the electrons released moved more slowly). They thus confirmed predictions by Edward Condon (1938) and Robert Andrews Millikan .

While studying the spectroscopic properties of alkali halide crystals, especially potassium iodide, he discovered exciton- induced photoemission in 1950 with E. Taft .

In 1948, he invented the flash filament method in vacuum technology for measuring very low pressures: gas adsorption on a tungsten wire over a certain period of time is measured by the pressure that is generated when the wire is suddenly heated by the release of the adsorbed gas.

In 1955 he received the Oliver E. Buckley Condensed Matter Prize .

The American Physical Society's LeRoy Apker Award is named after him. It is awarded annually to undergraduates for outstanding achievement and is endowed with 5000 dollars.

Web links

  • Leroy Apker. In: Array of Contemporary American Physicists. Retrieved October 15, 2012 (biography from AIP).

Individual evidence

  1. ↑ L. Apker, E. Taft, J. Dickey: Photoelectric Emission and Contact Potentials of Semiconductors . In: Physical Review . tape 74 , no. 10 , November 15, 1948, p. 1462-1474 , doi : 10.1103 / PhysRev.74.1462 .
  2. ↑ L. Apker, E. Taft: Photoelectric Emission from F-Centers in KI . In: Physical Review . tape 79 , no. 6 , September 15, 1950, p. 964-966 , doi : 10.1103 / PhysRev.79.964 .
  3. ↑ L. Apker, E. Taft: exciton Enhanced Photoelectric emission from F-centers in RbI near 85 ° K . In: Physical Review . tape 81 , no. 5 , March 1, 1951, p. 698-701 , doi : 10.1103 / PhysRev.81.698 .
  4. ↑ Le Roy Apker: Surface Phenemona Useful in Vacuum Technique . In: Industrial & Engineering Chemistry . tape 40 , no. 5 , May 1, 1948, p. 846-847 , doi : 10.1021 / ie50461a016 .
  5. ↑ Apker Awards
personal data
SURNAME Apker, LeRoy
BRIEF DESCRIPTION American physicist
DATE OF BIRTH June 11, 1915
PLACE OF BIRTH Rochester (New York)
DATE OF DEATH 1970