secondary emission

secondary emission
the emission of electrons (secondary electrons) from a material that is bombarded with electrons or ions.
[1930-35]

* * *

      ejection of electrons (electron) from a solid that is bombarded by a beam of charged particles. Some electrons within the surface of a material are given enough energy to break free from the attractive force holding them to the surface by a transfer of kinetic energy from the bombarding particles. For a given energy, electrons themselves are a more efficient bombarding particle than the much heavier ions (ion) (atoms (atom) that have lost or gained at least one electron). An excellent target material is cesium oxide, which may emit a current of secondary electrons 10 times stronger than the primary, or bombarding, current. This magnification of the electron current by secondary emission is an essential feature of photomultiplier tubes (photomultiplier tube) used to detect weak electric currents (electric current), especially in certain radiation detectors. The effect also is employed in image intensifiers that produce a bright image of a faintly illuminated object.

      Ions, too, may be ejected from solids by secondary emission produced when positive ions bombard their surfaces.

* * *


Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Secondary emission — is a phenomenon where additional electrons, called secondary electrons, are emitted from the surface of a material when an incident particle (often, charged particle such as electron or ion) impacts the material with sufficient energy. The number …   Wikipedia

  • secondary emission — n. 1. the emission of electrons (secondary electrons) from a material, following impact by high speed electrons 2. the emission of electrons or electromagnetic radiation from a liquid, solid, or gas, following impact by a charged particle or… …   English World dictionary

  • secondary emission — n the emission of electrons from a surface that is bombarded by particles (as electrons or ions) from a primary source …   Medical dictionary

  • secondary emission —  Secondary Emission  Вторичная эмиссия   Испускание элементарных частиц веществом, например, газом или металлической поверхностью, при бомбардировке его первичным (только что порожденным) излучением или частицами. Так, вторичные космические лучи… …   Толковый англо-русский словарь по нанотехнологии. - М.

  • secondary emission — noun the emission of electrons from a surface that is bombarded by higher energy primary electrons • Hypernyms: ↑emission * * * noun : the emission of electrons from a surface that is bombarded by electrons or ions from a primary source * * * the …   Useful english dictionary

  • secondary emission — antrinis spinduliavimas statusas T sritis fizika atitikmenys: angl. secondary emission; secondary radiation vok. Sekundärstrahlung, f rus. вторичное излучение, n pranc. émission secondaire, f; radiation secondaire, f …   Fizikos terminų žodynas

  • secondary emission — antrinė emisija statusas T sritis fizika atitikmenys: angl. secondary emission vok. Sekundäremission, f rus. вторичная эмиссия, f pranc. émission secondaire, f …   Fizikos terminų žodynas

  • secondary emission current — antrinės emisijos srovė statusas T sritis fizika atitikmenys: angl. secondary electron current; secondary emission current vok. Sekundärelektronenstrom, m; Sekundäremissionsstrom, m rus. ток вторичной эмиссии, m; ток вторичных электронов, m pranc …   Fizikos terminų žodynas

  • secondary emission factor — antrinės emisijos faktorius statusas T sritis radioelektronika atitikmenys: angl. secondary emission factor vok. Sekundäremissionsfaktor, m rus. коэффициент вторичной эмиссии, m pranc. taux d émission secondaire, m …   Radioelektronikos terminų žodynas

  • secondary emission method — antrinės emisijos metodas statusas T sritis Standartizacija ir metrologija apibrėžtis Analizės metodas, pagrįstas antrine elektronų arba jonų emisija. atitikmenys: angl. secondary emission method rus. вторичноэмиссионный метод, m pranc. méthode… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”