The Secret Lives of Particle Accelerators

The most complex machines ever built don't just hunt for obscure subatomic bits

Beneath the French-Swiss border, the Large Hadron Collider will help scientists seek answers to some of the most profound questions about the universe. Beyond this lofty goal, though, particle accelerators can be used for decidedly more down-to-Earth projects — like fighting cancer, cleaning up industrial waste and even shrink-wrapping your Thanksgiving turkey. More than 17,000 particle accelerators are in operation around the world, used for radial tires, computer chips and 3-D images of molecules, among other tasks.

The LHC, which was restarted this week, will run at half its maximum energy for the next year and a half, as scientists monitor electrical systems that have already forced delays. At 3.5 trillion electron volts, a half-power LHC will still be three times as powerful as the world’s previous atom-smashing king, Fermilab’s Tevatron.

As the LHC searches for the elusive Higgs boson, which is thought to endow all other particles in the universe with mass, we decided to takes a look at some other, perhaps more humble uses for particle accelerators, the “cathedrals of science.” Launch the gallery below:

Additional reporting by Molly Webster

Better X-Ray Machines Image Ancient Fossils in 3-D

The world’s most powerful X-ray machines are a byproduct of high-energy physics. Synchrotron particle accelerators are helping shed light on some of the world’s rarest fossils. Last spring, a synchrotron helped scientists create a 3-D image of a 300 million year-old brain. Synchrotrons use magnetic and electric fields to send electrons careening along a circular path; the process radiates X-rays that can be used to illuminate structures as small as atoms. In March 2009, scientists from France and the U.S. announced they had X-rayed remnants of a brain inside an Iniopterygian fossil from Kansas. Iniopterygians are extinct relatives of modern ratfishes, also known as “ghost sharks” or chimaeras. Chimaeras are related to sharks and rays. Like some of the best discoveries, it happened by accident. The team was using the synchrotron at the European Synchrotron Radiation Facility in Grenoble, France, to study the rare 3-D fossil (most are squashed flat), and the researchers noticed part of the fish’s head was denser than normal. Using X-ray holotomography — holographic mapping, basically — they realized they were looking at fossilized brain tissue. Along with studying fossils, accelerators can be used to search for priceless works of art. Some art historians believe Leonardo da Vinci’s greatest painting is hidden inside a wall in Florence’s city hall. Last fall, the New York Times reported on an Italian scientist’s plans to beam neutrons through the wall in hopes of finding the lost painting.

Onward and Upwards in Shrinkwrap Innovation

Next time you tuck into a freshly roasted turkey, give thanks to high-energy physics. The Butterball thawing in your fridge the week before Thanksgiving wouldn’t be possible without it. Heat-shrinkable film, or shrink wrap, is made from polyethylene plastic, which consists of long polymers strung together. The carbon atoms in the plastic are saturated, having bonded with two hydrogen atoms. Heated to the boiling point of water, the plastic melts. But when they are zapped with a beam of electrons from a particle accelerator, the polymer chains are desaturated. The hydrogen atoms get kicked out, and carbon atoms form bonds with other carbon atoms. Carbon chains are really strong, and can withstand extreme heat without breaking down. Once it cools down, the new, stronger plastic retains its expanded shape, and will accommodate anything from a turkey to a new CD to a Sea Knight Navy helicopter. Once heat is applied, it shrinks again, creating an air-tight, durable wrapping.

Fighting Cancer

Since the earliest days of particle accelerators, scientists and doctors have used healing beams of protons to kill cancer cells. Ernest Lawrence, the father of the cyclotron, used his invention in its infancy to treat his mother’s cancer. In 1938, just nine years after her son built the first cyclotron, Gunda Lawrence became the first cancer patient to be treated successfully with particles from cyclotrons, according to a medical archive maintained by Fermliab. text Today, accelerators producing X-rays, protons, neutrons or heavy ions can be found at every major medical center in the U.S. In December, the University of Pennsylvania dedicated its new $140 million Roberts Proton Therapy Center, the largest of its kind in the world. That cyclotron’s energy beam will be directed to five treatment rooms, each over two stories tall. Proton beams can be easily controlled because they are so precise; their accuracy makes them well suited for treating cancers in the brain, head, neck, eye and spinal cord, and in hard-to-reach organs like the liver, pancreas, and esophagus, according to the Penn School of Medicine. In this photo, a patient receives treatment at Loma Linda University Medical Center in California, the world’s first proton accelerator built specifically for a medical environment. The synchrotron accelerator was built at Fermilab and the first patients were treated in 1990.

Stop-Motion Photography on a Molecular Level

Accelerators have long been used to take photographs — magnetic resonance imaging, MRI, evolved from the magnets physicists used to speed up subatomic particles. Today, accelerators can take detailed images of individual molecules and even atoms in action. The SLAC Linear Accelerator Center at Stanford University is now home to the Linac Coherent Light Source, which acts as an ultrafast strobe light taking stop-motion pictures of atoms and molecules. Last year, the venerable two-mile-long linear accelerator, where charmed quarks were discovered, was converted into a new kind of powerful laser that will create super-brilliant X-ray pulses. The pulses are a billion times brighter than the light created by the most powerful synchrotron sources, and are used like flashes from a high-speed strobe light. The X-ray pulses have a shutter speed of less than 100 femtoseconds (100 femtoseconds = 1/10 of a trillionth of a second). Other accelerators are already used to take pictures of human proteins at work, helping doctors understand diseases and medicines. Researchers at the Advanced Photon Source at the Department of Energy’s Argonne National Laboratory have imaged insulin molecules and how they bind to human glycoprotein, in an effort to understand the prevention of juvenile diabetes.

Fighting Pollution

Beams of electrons can help clean water and air by breaking down pollutants into different molecular compounds. Though pilot tests were conducted in the late 1980s, today no facilities in the U.S. treat wastewater or sewage sludge with accelerated electrons. A number of countries in Asia, Europe, and the Middle East are pursuing the technology, however. In one coal power plant in Poland, flue gas is converted into sulfur and nitrogen byproducts that can be used as fertilizer. According to a study out of Daegu, Korea, an electron-beam accelerator inside a textile factory can remove toxic dye from 10,000 cubic meters of wastewater every day. Another study by the Russian Academy of Sciences showed electron beams successfully removed petroleum products, including diesel fuel, motor oil and residual fuel oil, from water. Along with cleaning up waste, particle accelerators help prevent more of it from accumulating on our coffee tables and our roads. Particle accelerators are used to create a paper substance that covers much modern furniture, preventing scratches and stains, and they’re used to treat material for radial tires, eliminating the use of solvents that pollute the environment.

Nuclear Weapons Forensics

It’s unlikely that particle accelerators could be used as weapons — although subatomic particles are careening through them at almost the speed of light, the energy of their collisions is almost immeasurably small. (If the LHC was operating at its full 7 trillion electron volt capacity, the colliding particles’ energy would equal what you’d get from eating 0.00013 micrograms of a candy bar.) But accelerators could be used to take inventory of weapons stockpiles, for instance, or to understand how materials have been modified, according to Jay Davis of the Hertz Foundation, who was the founding director at the Center for Accelerator Mass Spectrometry at Lawrence Livermore National Laboratory. He said at an accelerators conference last fall that accelerators could be used for forensics, such as determining a material’s origin, or for taking high-resolution pictures. Other security applications could include using neutrinos, which penetrate the Earth, to communicate with submarines. In the 1980s, some particle physicists even studied accelerator technology for use in the Strategic Defense Initiative, known as the Star Wars program, depicted in this 1984 artist’s impression.

Irradiating Food

Like pasteurization, irradiation kills bacteria and pathogens that can spoil food and make you sick. The difference is that it relies on radiation instead of heat. Though it’s fairly uncommon to see irradiated steaks in your grocer’s meat case, electron beam irradiation is a well-established practice, according to the U.S. Environmental Protection Agency. The food is not exposed to radioactive materials — rather, it’s zapped with a radiation beam, which the EPA compares to a big flashlight. The electron beams work by interfering with microorganism DNA. As shown in this diagram, food, such as large cuts of meat or packaged products, is placed on a conveyor belt under the electron beam. The belt moves at a certain speed, depending on the dose. Electron beams and X-ray accelerators can both be used to irradiate various shapes and sizes of food, although X-rays are better at penetrating large items. Iowa State University operates a linear accelerator attached to a slaughterhouse and a lab where researchers can examine the irradiated products.

Nuclear Cleanup and Nuclear Fusion

Modern nuclear power plants use nuclear fission, which splits atoms apart. But accelerators could potentially produce nuclear fusion, which fuses atomic nuclei together. Fusing heavy hydrogen isotopes requires lots of energy, partly because the nuclei are positively charged and repel each other. But a powerful beam of subatomic particles could be used to crush nuclei together strongly enough so they fuse. The U.S. Department of Energy has studied the concept. Until fusion power plants are built, accelerators can be used to clean up the fission ones. Scientists at Los Alamos National Laboratory are studying the use of particle accelerators to reduce nuclear waste. Most nuclear reactor waste is uranium, which by itself doesn’t need long-term storage. But roughly 5 percent of reactor waste is highly radioactive fission products, including plutonium and other actinides. The U.S. nuclear power industry will generate roughly 70,000 tons of high-level nuclear waste by 2015, according to Los Alamos. That includes about 550 tons of plutonium. Accelerator transmutation of waste, or ATW, could shrink that number to about 3,000 tons total, including than 1 percent plutonium. What’s more, the waste would only require a few centuries of storage, instead of 10,000 years. It works by cooking the uranium and its daughter products, called transuranics, with a focused proton beam. At an ATW treatment center, the uranium and some other less-hazardous material would be separated from the rest of the waste. Then the remaining transuranics would be transferred to a burner to be fissioned into more stable materials. The fission process would be controlled using neutrons produced by a linear accelerator’s proton beam. The best part is that the process can power itself — plutonium releases energy as it destroyed by fission, and that energy can power the burner. The niobium superconducting cavities shown here could prove useful for waste transmutation. That’s still just a theory, however. But it brings us to our next entry …


For centuries, scientists have tried to turn base metals into precious ones, most commonly lead into gold — even Isaac Newton, the father of modern science, was an alchemist. The mythical philosopher’s stone, or sorcerer’s stone, is said to be a chemical substance capable of turning lead into gold. Alchemy, or transmutation, has placed new elements on the periodic table, including plutonium. Nobel laureate Glenn Seaborg co-discovered 10 of those elements, including plutonium, and in 1980, he reportedly succeeded in transmuting several thousand bismuth atoms into gold atoms at Lawrence Berkeley National Laboratory. The process stripped protons and neutrons from the bismuth atoms, lowering the atoms’ weight to that of gold atoms. Despite this apparent success, it would be far too expensive and impractical to actually use this process to turn a tiny amount of atoms into gold. But hey, if particle physicists get this one down, the next LHC could pay for itself.

Breaking the Laws of Physics

As the Brookhaven National Laboratory proved this week, it’s possible — at least briefly. Scientists announced Monday that in a quark-gluon plasma, achieved by smashing gold nuclei together at 99.995 percent of light speed, quarks briefly lost their ability to tell right from left. This anomaly, which breaks the laws of physics, lasted a billionth of a billionth of a billionth of a second. A similar phenomenon, called symmetry breaking, is thought to have occurred shortly after the Big Bang and upset the balance between matter and antimatter, leaving the universe with more matter. Watch an animation of the discovery here.