| 摘要 |
The invention relates to a fluorescent-lighting appliance, comprising an external translucent envelope which on the inside is covered with a material which fluoresces when exposed to ultraviolet light. The envelope contains a virtually inert gas which can be ionized when bombarded with electrons from a cathode, whilst the outer envelope encloses a cathode and an anode, said cathode having a number of openings or grooves which are delimited on either side by surfaces consisting of, or covered by, a metal or metal-containing preparation which provides a work function of less than 3.0 electron-volts and contains atoms of a metal which is able to emit radiation in the ultraviolet region of the spectrum. After ionization of the metal atoms in the gas phase and after extraction of such atoms into the gas phase by impingement of ions from the gas phase onto the coating layer, the pressure of the inert gas in the envelope being between the following limits: 2.0 < p x d/1.33 < 3.0, where p is the pressure of the gas in millibar and d is the distance in centimetres between the surfaces situated opposite one another 74, 104 (or 2.0 < p* x d < 3.0, if p* is the pressure of the gas in mm Hg) [lacuna].
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