Change of the arc attachment mode and its effect on the lifetime in automotive high intensity discharge lamps
| Autor: | J. Mentel, Alexander Alexejev, Peter Awakowicz, Peter Flesch |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Gas-discharge lamp Chemistry business.industry Analytical chemistry General Physics and Astronomy chemistry.chemical_element Sodium-vapor lamp Tungsten 01 natural sciences 010305 fluids & plasmas law.invention Xenon law 0103 physical sciences Electrode Optoelectronics Scandium Gas-filled tube business Common emitter |
| Zdroj: | Journal of Applied Physics. 120:133301 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.4963280 |
| Popis: | In modern cars, the new generation Hg-free high intensity discharge (HID) lamps, the so called xenon lamps, take an important role. The long lifetime of these lamps is achieved by doping the tungsten electrodes with thorium. Thorium forms a dipole layer on the electrode surface, thus reducing the work function of tungsten. However, thoriating the electrodes is also an issue of trade and transport regulation, so a substitute is looked into. This work shows the influence of the arc attachment mode on the lifetime of the lamps. The mode of the arc attachment changes during the run-up phase of automotive HID lamps after a characteristic time period depending, i.e., on the filling of the lamps, which is dominated by scandium. It will be shown that this characteristic time period for the change of the attachment mode determines the long term performance of Hg-free xenon lamps. Measurements attributing the mode change to the scandium density in the filling are presented. The emitter effect of scandium will be suggested to be the reason of the mode change. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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