The physics of discharge lamps

Photonic superdiffusive motion in resonance line radiation trapping Partial frequency redistribution effects

“…For strong resonance lines with short lifetimes the frequency redistribution is partial since only a few collisions occur before emission, and consequently the stochastic nature of the distribution must be considered. Partial Frequency Redistribution (PFR) effects are important in an astrophysical context, as is the case of the scattering of Lyα radiation in optically thick nebulae [20] and the Ca I resonance line in the solar spectrum [21], as well as in lab scale atomic vapors, notably the 185 nm mercury line in low-pressure lighting discharges (which can account for as many as 10% of the overall flux in a typical T12 fluorescence lamp) [22] and the 147 and 129 nm Xe VUV radiation used in Plasma Display Pannels (PDPs) applications [23,24]. For both mercury and xenon, the natural lifetimes of the corresponding excited states are less than about 3 ns and therefore only at very high densities is the collision rate high enough to approach CFR conditions.…”

The Metal-Halide Lamp Under Varying Gravity Conditions Measured by Emission and Laser Absorption Spectroscopy

“…They are high pressure lamps based on arc emission (Stormberg 1981;Rogoff et al 1987;Zollweg 1975;Dakin and Shyy 1989;Lister et al 2004;Bonvallet and Lawler 2003). These lamps are mainly used for outdoor applications; examples are shop lighting, street lighting, flood lighting of sport stadiums and city beautification.…”

“…These lamps are mainly used for outdoor applications; examples are shop lighting, street lighting, flood lighting of sport stadiums and city beautification. HID lamps have a high efficiency (up to 40%) (Lister et al 2004) and emit white light.…”

Note: Measuring breakdown characteristics during the hot re-ignition of high intensity discharge lamps using high frequency alternating current voltage

“…HID lamps are used in practical applications where there is a need for high intensity light from a small volume, for example xenon car headlights, stadium lighting, lighting in shops, and other indoor applications. 2,3 This broad range of use of HID lamps drives the research in the ignition of those lamps, especially in cases where fast and reliable ignition of the lamp is desired.…”

“…In a cold lamp the main component in the gas phase is a noble gas at low pressure which determines the ignition or breakdown voltage. 3 After the lamp has been ignited, the noble gas heats up and the vapor pressures of mercury and metal halide salts start to increase. Due to the addition of the buffer gas and metal halide salts to the gas phase, the pressure inside the lamp will increase to several bars during operation.…”