Lead glass

In the lead crystal glass that variety, replacing the alkaline earths contained in many glasses as calcium oxide by lead oxide. The proportion of genuine lead crystal glass has to be at least 24%. Cut lead glass is often referred to as lead crystal. Lead crystal glass is clear even in thick-walled vessels and can be sanded well. Lead crystal glass is characterized by a high refractive index, colorless, shine and a beautiful sound. It is also characteristic, the high density of 3.5 to 4.8 g/cm3.

For a glass having at least 18 % PbO, the term press- lead crystal is used, more than 30 % of lead oxide contained is referred to as high- lead crystal.

The definition of lead glass results from the Zschimmerschen usually alkali content = (76% - % PbO ) x 0.27, where the vast alkali content is introduced by K2O.

Applications

A lead glass with very high lead oxide content (> 40 %) is the flint glass used in optics.

The rhinestones used as a gemstone replacement is also a special lead glass.

Due to the high density window with leaded glass for shielding of radiation sources in radiology, nuclear medicine, in technology and in the manufacture of cathode ray tubes used (eg in TV ), where a clear view of the radiation field or to the generated image necessary is.

Lead glass is used in nuclear and particle physics as the detection medium and the energy determination of fast, charged elementary particles. This lead glasses in the form of typically 20 to 30 centimeters long blocks are stacked to form walls, at the back of the resulting in lead glass Cherenkov radiation with photomultiplier tubes ( PMT ) is converted into voltage signals. Such lead glass walls can consist of several thousand blocks and thus cover areas of several square meters. Due to their use for energy measurement of electrons, positrons and photons lead glass walls are also attributed to the electromagnetic calorimeters. An example of a proof detector with large leaded glass walls of -been in operation at CERN universal detector of the UA2 experiment for the study of proton -antiproton collisions.

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