Sitall (also known as Sitall CO-115M or Astrositall) is a crystalline glass-ceramic with ultra-low coefficient of thermal expansion (CTE). It was originally manufactured in the former Soviet Union and was used in the making of primary mirrors for the Russian Maksutov telescopes, but since dissolution has diminished in quality.[1] It has a CTE of only 0 ± 1.5×10−7 °C−1 in the temperature range −60 to 60 °C, placing it in a small group of transparent materials with low CTE such as Vycor, Zerodur, Cer‑Vit and fused quartz.[2]
Materials of low coefficient of thermal expansion are critical in the manufacture of optical elements for telescopes. In segmented mirror telescopes, it is desirable to have this coefficient as near zero as possible, and to have a high degree of homogeneity in the material. The Southern African Large Telescope (SALT) selected Sitall for the manufacture of its 91 primary mirror segments by Lytkarino Optical Glass Plant. The choice arose out of increased scientific collaboration between Russia and South Africa since 1994.[3][4][5] Sitall was also used for the primary and secondary mirrors of the VLT Survey Telescope.
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^"Welcome to Star Instruments Online!". Star-instruments.com. Retrieved 9 November 2014.
^"South Africa and Russia consolidate scientific ties". Engineeringnews.co.za. Retrieved 9 November 2014.
^[1] [dead link]
^"LZOS". Spiedlaop.org. Retrieved 9 November 2014.
Sitall (also known as Sitall CO-115M or Astrositall) is a crystalline glass-ceramic with ultra-low coefficient of thermal expansion (CTE). It was originally...
Rod. "Thermal Expansion Coefficients at 20 C". Georgia State University. "Sitall CO-115M (Astrositall)". Star Instruments. "Thermal Expansion table" (PDF)...
alloy with relatively constant elasticity over a range of temperatures Sitall and Zerodur, ceramic materials with a relatively low thermal expansion Borosilicate...
substantially similar to other glass CorningWare Macor Ring laser gyroscope Sitall "Secondary Mirror of ELT Successfully Cast - Largest convex mirror blank...
ceramic inserts covering the base M60A1 vehicle. Track skirts consisted of Sitall and high-hardness steel for the hull sides as well as Kevlar spall liners...
arcminutes at prime focus. Each of the 91 mirrors is made of low-expansion Sitall glass and can be adjusted in tip, tilt and piston in order to properly align...
Avanhard M. Shakhtar T. Sitall Shakhtar Azovets Shakhtar KL Khimik Komunarets Shakhtar K. none FC Stal Dnipropetrovsk FC Sitall Kostiantynivka none Source:...
camera. Both mirrors are made from a crystalline ceramic material called Sitall, chosen for its low coefficient of thermal expansion. The VST primary mirror...
1868—2003 годы [The history of Itkul Distillery, 1868—2003] (in Russian). Sitall. ISBN 5-98708-001-0. "Иткульский спиртзавод". Алтайская краевая универсальная...
Shakhtar H Lokomotyv D. Start Avanhard Kr. Avanhard M. Shakhtar T. Uholyok Sitall Industriya Shakhtar S. Shakhtar KL Avanhard R Komunarets Avanhard A One...
Shakhtar H Lokomotyv D. Start Avanhard Kr. Avanhard M. Shakhtar T. Uholyok Sitall Industriya Shakhtar S. Shakhtar KL Avanhard R Komunarets Shakhtar K. none...
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