Gaseous discharge lamps

Gaseous discharge lamps which contain internal electrodes also can serve as sources for atomic absorption. They are variously called arc lamps, spectral lamps, vapor lamps, and by the name of the manufacturer, such as Osram lamps and Philips lamps. Gaseous discharge lamps contain an inert gas at low pressure and a metal or metal salt. They are especially suited to metals of relatively high vapor pressure, such as the alkali metals and some other metals such as mercury, cadmium, and lead. 

Gaseous discharge lamps have been useful as sources, particularly for alkali metals, because hollow cathode sources for these elements are troublesome. Recent improvements in alkali metal hollow cathode sources have led to their increasing use. 

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Gaseous Discharge Lamps. Gaseous discharge lamps consist of an electrically operated source of radiant energy characterized by the emission of radiation from a stream of ionized gas carrying current between electrodes in the lamp (See Fig G10). Lamps in common use include fluorescent, mercury-vapor and neon lamps. In general,... 

In a photoelectric experiment monochromatic radiation, 1w, causes ionization of matter, and the properties of the ejected electrons are measured. Radiation is of three main types X-ray, U.V. (normally from an inert gas discharge lamp), and synchrotron radiation. The matter is usually in the solid or gaseous state, though some experiments have also been carried out on liquids and on matrix isolated species. Measurement of the kinetic energy, m v2, of the ionized electrons and use of the Einstein equation... 

Neon lamps generate a pleasant pink-red glow. Gaseous neon within the tube (at low pressure) is subjected to a strong electric discharge. One electron per neon atom... 

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