It's also an intriguing success story for science. Painted in 1876, Edgar Degas' 'Portrait of a Woman' is a striking example of French Impressionism. Here at Diamond, we use lead (and steel, and concrete) to shield the optics and experiment hutches on the beamlines and keep staff and users safe when the beam is on. Lead's high density and high atomic number mean it's great for stopping X-rays and gamma rays. One of the more modern uses of lead is for radiation shielding, protecting living organisms from the damage that can be inflicted by ionising radiation. The tetraethyl lead added to petrol for decades poisoned children and increased inner-city crime rates. This was brought to light in America by the water crisis in Flint, Michigan. Lead water pipes were common until the 1950s, and although they were later banned, ageing infrastructure can lead to lead poisoning. However, lead is toxic, and our historic uses cause problems today. Several towns in the USA are named galena, due to their mining history. It's also the state mineral of Wisconsin, where lead mining has been taking place since at least the 17th century. The largest lead deposits in the world are in Missouri (USA), which made galena the state mineral in 1967. Later they traded the ore to European settlers and learned how to melt it and form metal objects from them. Some Native Americans used lead to create black body paint, by grinding up the ore and mixing it with water. The smelting process can be as simple as putting rocks in a fire and extracting the lead from the ashes. Lead is relatively abundant, and our ancestors discovered that they could easily extract it from galena, lead sulfide ore. They traced the ores used to make it to the Taurus mountains (in what is now Turkey). Researchers found a smelted lead object dating back to the late 4000s BCE in Israel. We know that humans have been making use of lead for a very long time. Gallium and indium are semiconductors, and thallium is highly toxic and has been used as a pesticide.Ī soft metal with a low melting point, lead is easily shaped and doesn't corrode much, making it incredibly useful. Lead is now used in alloys, solder, and roofing. Lead is one of the seven metals of antiquity that humans identified and made use of in prehistoric times (the other six are gold, silver, copper, tin, iron, and mercury). Notable uses include bullets, and radiation shielding. A freshly cut lead surface is silvery blue, but it tarnishes to dull grey on exposure to air. Soft and malleable, it has a relatively low melting point. Lead is a heavy metal, with the highest atomic number of any stable element. Most are soft or brittle, with poor mechanical strength, and have melting points lower than the transition metals. These metallic elements include aluminium, gallium, indium, tin, thallium, lead, and bismuth. In the periodic table, the post-transition metals sit between the transition metals on their left, and the metalloids on their right. The second collimator (detector slits) is placed just in front of the detector front-plate and is hidden behind lead shielding. EDXD detector on Module 2 of Large Detector Table 2 (LDT2) on our I12 beamline.
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