Earth metals aren't the only rare elements that are essential to modern technology. Helium, the lighter-than-air gas that buoys balloons, also plays roles in powering space shuttles, modern electronics and next-generation nuclear reactors.
Helium, a nonrenewable resource that's extracted from natural gas, has been getting scarce in the U.S., according to speakers at a U.S. Senate hearing held May 11. The U.S. has an enormous Federal Helium Reserve – originally created in the 1920s, when the government considered using blimps as military aircraft – but it's been selling off its supply at artificially low prices, according to a 2010 report by the National Research Council. To better meet demand, the Senate hearing considered a bill that would change how the reserve sells helium.
A helium shortage would affect the U.S. in myriad ways. Besides filling balloons, the element helps cool the superconducting magnet in MRI machines, which doctors use to diagnose cancers, brain injuries and more. Beyond MRIs, the extremely stable gas is also important to high-tech science and defense in the U.S.
According to a U.S. Geological Survey report, almost a third of the helium the U.S. used last year went to cryogenics, the study of very low temperatures and its effects. Helium is a stable refrigerant that is able to cool things down to thousandths of a Kelvin, or less than minus 450 degrees Fahrenheit (minus 267 degrees Celsius). No other coolant on Earth compares.
Liquid helium cools the superconducting equipment in particle accelerators, including several facilities in the U.S. and the Large Hadron Collider in Europe. Accelerators can be several miles long and require cooling all along their bodies, so they use large amounts of helium. Once an accelerator is filled with helium, however, it is able to continually reuse the refrigerant, so researchers only need to top off the supply to account for the small amount that leaks and drifts away from the accelerator every year.
Super magnets and brain cell research
Labs all over the U.S. use liquid helium to cool instruments that will only work at super-low temperatures. The devices that measure very small magnetic fields for brain cell research need liquid helium, for example, as do the world's most powerful magnets. Liquid nitrogen can work as a replacement in some cases, but it doesn't reach temperatures as low as liquid helium.
Helium is also important to Internet use. One method of creating semiconductors, which appear in virtually all electronic devices today, requires liquid helium to cool the magnets used in the manufacturing process. Meanwhile, the fiber optic cables that bring Internet access and cable TV to people's homes need to be made in an all-helium atmosphere to prevent bubbles from getting trapped inside.
Military and defense
The U.S. military's submarine detectors use liquid helium to clean up noisy signals, and the U.S. Air Force uses helium in experiments on superconductors as a power source, according to the National Research Council. Liquid helium is also important as a reference point for heat-guided missiles, Peter Madrid, a helium analyst for the U.S. Bureau of Land Management in Amarillo, Texas, told InnovationNewsDaily.
Space shuttles use liquid hydrogen and oxygen, not helium, for fuel. But they still need liquid helium to clean out their fuel tanks. Because the tanks are so cold, other liquids would freeze and clog the pipes. Other materials may also react with lingering oxygen in tanks and explode, but helium is inert and won't combust.
The party balloon industry actually uses "significant amounts of helium," according to the National Research Council, but they're not the only balloons out there. Weather balloons, research balloons and Department of Defense survey balloons all use helium. The Department of Defense is currently developing a helium-filled balloon called JLENS that would permanently survey U.S. skies for cruise missiles.
Magnetic resonance imaging machines require liquid helium to cool the superconducting magnet that provides their magnetic field. Doctors use MRIs to diagnose cancers, tumors, strokes, heart damage and brain diseases, while researchers use them for experiments in chemistry, biology and medicine. Newer machines use "dramatically less helium," but developing a magnet that doesn’t need any liquid helium would take at least five years and may not happen at all, according to the National Research Council.
Next-gen nuclear reactors
The next generation of nuclear power plants may need helium as a coolant. U.S. labs are working on creating high-temperature reactors (700 to 900 degrees Celsius, or 1,292 degrees to 1,742 degrees Fahrenheit) and very-high-temperature reactors (more than 1,000 degrees Celsius, or 1,832 degrees Fahrenheit) that would be safer, more affordable and faster to build than current reactors. Researchers aren't sure yet how much helium a reactor would use, National Research Council scientists said.
The future of helium in the U.S.
If the U.S. does face a helium shortage in the future, it will have to ramp up its helium recycling programs. "It is imperative to look into recycling programs," Madrid said. MRI machines and fiber optic company Owens Corning already recycle their helium.
The U.S. will also try to extract more helium from its land. The U.S. Geological Survey found Qatar and Algeria have major helium deposits, but because a domestic supply would be much cheaper, Madrid said it's unlikely the U.S. will start importing more helium. The U.S., which imports only minute quantities of helium now, will just drill for more domestically. "It's highly unlikely if the United States does not make advances to seek out new gas-bearing fields for helium," he said.
The Bureau of Land Management already knows which natural gas deposits probably have high helium content: those in Wyoming, southeastern Utah and central-eastern Arizona.