Mercury-xenon lamps

Figure 5. Absorbance at 300 run of thermally degraded PVC films irradiated with unfiltered light from a high-pressure mercury-xenon lamp in the presence of various pressures of HCl (21). (0-0) 0 (X-X) 50 ( - ) 300 ( - ) 760 torr.

The spectral irradiance of a typical mercury xenon lamp is shown in Figure 45. There is a characteristic high intensity mercury emission at 313 nm and a low intensity emission at 334 nm The MUV projection printing tools isolate these two lines through insertion of band-pass filter sets into the optical path, such that little or no light to the blue of 300 nm or to the red of 350 nm is transmitted to the resist surface. The transmission of a filter set of this sort for the Perkin Elmer Micralign 500 is shown in Figure 46. 

Figure 45. The relative spectral irradiance of a high pressure mercury xenon lamp of the sort commonly used in optical aligners.

Mercury-xenon lamp for small area curing. (Courtesy of Hologenix Company.)... 

High Pressure Lamp.—A lamp filled with mercury or xenon vapor (or a mixture of them) operated at about 10 or more atmospheres pressure. Although the total output is very high, the emission is largely above 3000 A. In mercury or mercury-xenon lamps it consists of broad lines superimposed on a strong continuum. The 2537 A. line is almost entirely lost by self-absorption in the lamp. 

Deep-UV source brightness is another issue, because the power output of a 1-kW mercury-xenon lamp in the 200-250-nm range is only 30-40 mW. For this reason, excimer lasers (such as KrCl and KrF), which can deliver several watts of power at the required wavelengths, are being considered as alternatives (7). In fact, a deep-UV step-and-repeat projection system with an all-quartz lens and a KrF excimer laser with an output at 248 nm has been reported (8). Even the laser-based systems require resists with a sensitivity of 30-70 mj/cm2. 

Figure 2. Fluorescence spectrum in a nitrogen matrix at 15 K (excited by a 2.5-kW mercury-xenon lamp) of an adsorption chromatography fraction from a coking plant water sample. Compounds BbF, benzo[b]fluorene C, chrysene BeP, ben-zo[e]pyrene P, pyrene BkF, benzo[k]fluoranthene BaP, benzo[a]pyrene U, unknown ( ).

Mercury/Xenon arc lamp If the arc is not focused sharply on the back aperture, the specimen plane will be unevenly illuminated. In addition, fluctuations in the illumination intensity of the lamp will also result in variable intensity over the whole field of view. In order to avoid this, it is better to consider a fluorescence microscope wherein the light coming from the mercury/xenon lamp goes through a quartz optical fiber for light scrambling, resulting in an even illumination and less fluctuations (Fig. 4). 

Mercury-xenon lamp (Arc) An intense source of ultraviolet, visible, and near infrared radiation produced by an electrical discharge in a mixture of mercury vapor and xenon under high pressure. 

See also antimony-xenon, lamp, mercury-xenon lamp (arc). 

WATT PRESSURIZED SHORT ARC MERCURY/XENON LAMP... 

The effect of irradiating the poly(carbon suboxide) film with the full spectrum of a 200 watt mercury-xenon lamp on the ESR spectrum is illustrated in Figure 6. There is a significant and rapid increase in the signal to a steady-state level intensity but no change in spectrum shape or line width. A scan of 500 to 5500 gauss showed no half field transition or absorptions at any other magnetic field. 

The UV photolysis studies were performed under vacuum or in air using an unfiltered high-pressure mercury/xenon lamp purchased from Oriel. The films were located 30 cm from the lamp and separated from it by a heat filter. The output from the lamp was 9.1 mW cm"2. 

Fig. 6. SpectFal solar and mercury-xenon lamp energy distribution.

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