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Helium FactsUnique Physical Properties
Helium has the lowest melting and boiling points. It exists as a gas except under extreme conditions. At temperatures close to absolute zero, helium is a fluid; most materials are solid when cooled to such low temperatures. Helium is found in natural gas. Geological conditions in Texas, Wyoming, Oklahoma and Kansas make the natural gas in those areas the most helium rich in the United States (from about 0.5 percent to 1.5 percent). Helium UsesHelium helps NASA’s shuttle get into space. The space shuttle’s main engines generate the enormous amount of power needed to propel the shuttle off the earth by burning liquid hydrogen and oxygen. When the fuel is burned it becomes a gas. Mixing of the hot gas and the ultra-cold liquid fuel would be very dangerous; they’re kept separate by a cavity that must be continuously purged by helium gas. Helium is important to anyone who needs an MRI scan to help diagnose their illness or injury. MRIs use superconducting magnets to generate an intense, steady magnetic field by cooling the wire to extremely low temperatures. Cooling the wire decreases resistance to electrical flow, enabling a stronger, steadier magnetic field. Superconducting magnets that require helium are also used in state-of-the art-particle physics research. Using particle accelerators, researchers at the Department of Energy’s Fermilab can make particles move at speeds close to the speed of light. When particles collide, they break into their component parts (like quarks) which can then be studied. When the particles fracture they release energy in the form of heat. Because helium is an effective heat conductor, it’s used to transfer this energy. Thermographic cameras detect heat instead of visible light. With this camera, search and rescue teams can locate people among rubble or through smoke. Technicians can identify overheated electrical equipment in need of repair. Medical professionals can monitor certain physiological processes. Liquid helium is used to cool some thermographic cameras. Cooled cameras are much more sensitive to minor variations in temperature. Various industries use helium to detect gas leaks in their products. Helium is a safe tracer gas because it is inert. Manufacturers of aerosol products, tires, refrigerators, fire extinguishers, air conditioners and other devices inject helium into the parts of their products that contain gas and put the part into a vacuum. Then they can measure whether or not any helium has leaked into the vacuum. The first laser invented, a helium-neon laser, is today used in laser eye surgery and laser pointers. Some additional uses of helium include:
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Helium has many special characteristics that make it an important resource. Of all the elements, helium is the most stable; it will not burn or react with other elements.