Owen Willans Richardson
1879–1959, Dewsbury, Yorkshire, England, Alton, Hampshire, England
English physicist who discovered the law of thermionic emission named after him; he received the 1928 Nobel Prize in Physics.
Richardson was born in Dewsbury, Yorkshire, and studied physics at Trinity College, Cambridge, under J. J. Thomson at the Cavendish Laboratory. In 1906 he moved to the United States as professor of physics at Princeton University, where he perfected his studies of thermionic emission and wrote the classic monograph The Emission of Electricity from Hot Bodies (1916).
He returned to Britain in 1914 to take the Wheatstone chair of physics at King's College London, later serving as director of physics research. He was knighted in 1939. His work on the electrons evaporating from heated metal wires laid the scientific foundation of vacuum tubes and electron sources.
Nobel-winning work
From 1901 to 1911, Richardson studied the electric current emitted by heated metal wires — the thermionic phenomenon already observed by Edison and others but never explained. He showed the current arose from electrons 'evaporating' from the metal over a surface potential barrier, and established the law J = AT²e^(−W/kT), in which current density grows as the square of absolute temperature and falls exponentially with the work function W.
Richardson's law allowed measurement of material work functions and revealed the quantum mechanism of emission — later refined into the Richardson–Dushman equation. The work underpinned vacuum tubes, cathode-ray tubes, and every modern electron source, and earned him the 1928 Nobel Prize in Physics 'for his work on the thermionic phenomenon and especially for the discovery of the law named after him'.
Workplaces: Princeton University, King's College London
United Kingdom