A Study of the Primary and Secondary Emission from Coated Cathodes with the Electron Microscope |
Common terms and phrases
700 volt electrons absolute zero activate or de-activate active coating band barium and oxygen barium and strontium barium atom barium in bulk barium on tungsten barium oxide bombarding voltage bombardment by 700 bombardment may activate broadened caesium compound de-activate a coating effect electric field electron bombardment electron microscope electrons leaving Emery Meschter energies greater energy loss FIGURE 17 filament focussed free barium function of tungsten Hence hour bombardment Images from secondary ionization potential layer of barium lenses lithium main tube mixture of barium molecule monatomic layer nickel OBJECT ASSEMBLY occupied Fermi levels oxygen and barium oxygen atom Oxygen on tungsten Phys positive barium positive ion bombardment Primary voltage producing a double reflected without energy rubidium secondary electrons Secondary Emission shown in Figure strontium oxide substances test temperature thick layer true secondary tungsten 4.5 volts tungsten lowers tungsten surface valence band valence electron valence level VIRTUAL LEVEL Vp 700 volts willemite