Secondary electron multiplier (VEU, English electron multiplier ) - an electronic device for amplifying (multiplying) the flow of electrons based on secondary electron emission . A wind turbine is either part of some electrovacuum devices (a photoelectron multiplier , an electron-optical converter , a number of transmitting electron-beam devices - dissectors , superorthicons, and others, as well as receiving-amplifying lamps), or it is an independent electrovacuum device that serves for direct registration of electromagnetic radiation (in the wavelength range of 0.1 - 100 nm) or particles (for example, electrons with energies up to 10 - 20 keV). Such receivers, which are executed without a shell or having an unprotected (open) input window, are called open type wind turbines. They are used in installations operating under natural vacuum conditions (during space research), and in high-vacuum measuring devices ( scanning electron microscopes , mass spectrometers , etc.) at pressures of usually not more than 10 −3 Pa.
Depending on the design, wind turbines are divided into two main groups: with discrete dynode systems, in which electron fluxes are multiplied by separate electrodes - dynodes , and the potentials of dynodes in such wind turbines increase stepwise, and with distributed (continuous) dynode systems in which electron fluxes are multiplied along surfaces with a continuous change in potential (channel electron multiplier, microchannel plates, etc.). Depending on the focusing of the electron fluxes, electrostatic focusing multiplying systems that are most widely used are distinguished from systems operating in crossed electric and magnetic fields.
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Literature
- A. G. Berkovsky, V. A. Gavanin, I. N. Zaydel. Vacuum photoelectronic devices. - M .: Radio and communications, 1988 .-- 272 p. - ISBN 5-256-00133-7 .
- M.R. Ainbund, B.V. Polenov. Open-type secondary electronic multipliers and their application. - M .: Energoizdat, 1981. - 139 p. - ISBN 5-283-03128-4 .