| 单词 | thermionic emission |
| 释义 | thermionic emission The emission of electrons, usually into a vacuum, from a heated conductor. The emitted current density, J, is given by the Richardson (or Richardson—Dushman) equation , i.e. J = AT2exp(-W/kT) , where T is the thermodynamic temperature of the emitter, W is its work function, k is the Boltzmann constant, and A is a constant. Thermionic emission is the basis of the thermionic valve and the electron gun in cathode-ray tubes. The equation was derived by the British physicist Sir Owen Richardson (1879–1959) from thermodynamics and later confirmed by the Russian-born US physicist Saul Dushman (1883–1954) using quantum mechanics |
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