Abstract by Scott Olsen
Physics and Astronomy
Extreme Ultraviolet Application Of Carbon Nanotube Collimator
Windows for extreme ultraviolet (EUV) sources are challenging because of the lack of transparent materials in these wavelengths. Thus, differential pumping apertures and slits are standard. Our group has developed a carbon nanotube (CNT) collimating window consisting of a dense array of square holes. The open high aspect ratio holes allow a large range of wavelengths to be collimated and the high density of holes gives a large open area. The aspect ratio restricts gas flow, allowing a large pressure difference with differential pumping. The versatility of CNTs allows us to select the collimating angle, peak transmission, and pressure ratio (low/high). We have observed at optical wavelengths collimating angle/peak transmission of 27°/0.93 and 37°/0.97 for (width-height in microns) 200-400 and 200-270, respectively; pressure ratios of 0.001, 0.0007, and 0.0005 have been observed for air at 298 K with 50-300, 50-650, and 50-1050 collimators, respectively for (high) pressures below 1 torr.