From University of California - Los Angeles
UCLA receives $4.8 million grant to support research in world’s best plasma physics facility In experiments that last a hundred-millionth of a second or just slightly longer, physicists are learning the secrets of plasma — the turbulent, hot, ionized, gas-like matter that may help us destroy toxic waste and chemical and biological weapons, and perhaps help generate unlimited energy through fusion.
UCLA’s Basic Plasma Science Facility has been awarded a $4.8 million grant by the U.S. Department of Energy and the National Science Foundation to become the country’s first national research facility for scientists worldwide to study the mysterious properties of plasma. Plasma is believed to make up more than 99 percent of the visible universe, including the sun, the stars, galaxies and the vast majority of the solar system. Plasma is a fourth state of matter, distinct from solids, liquids and gases, in which electrons have been stripped away to leave positively charged atoms or molecules.
“This is the best facility in the world for physicists to conduct controlled experiments to understand the properties of plasma — research that could have significant applications for this country,” said Tony Chan, dean of physical sciences in UCLA’s College of Letters & Science. “UCLA will be host to international physicists working at the forefront of plasma physics.”
The centerpiece of the facility is an enormous machine called the Large Plasma Device (LAPD), which weighs more than 80 tons.
Walter Gekelman, UCLA professor of physics and director of the facility, and five of his colleagues, built the machine — from the sophisticated electronics and the plasma source to the plumbing and welding — over three-and-a-half years. The machine is unique in the world, and allows physicists to create and analyze plasma and plasma waves of superheated, energized gas.
“Studying plasma waves in space is like finding one tooth of a dinosaur and trying to determine what the whole dinosaur looked like,” Gekelman said. “In our machine, we can see the whole dinosaur.
“Much about plasmas and how they behave is very poorly understood,” he said. “Our machine will help us understand plasmas. We can make measurements in tens of thousands of locations, using technology we have developed over 30 years.”
Experiments using LAPD last as little as a hundred-millionth of a second, and always much less than a one-thousandth of a second, Gekelman said. Plasmas in space support thousands of waves that may be 100,000 miles long, exist nowhere else in nature and dictate how the plasma behaves.
“We can study these waves in tremendous detail, and are able to scale them so they fit in our device,” Gekelman said.
Gekelman and his research team will use the facility half the time for research, and other physicists worldwide will propose experiments to use the LAPD for the other half. The Westwood facility operates 24 hours a day.
Plasmas could have many practical uses, including plasma torches that cut through steel like butter (which Gekelman used in making LAPD), weigh no more than a pencil and may eventually be used to destroy toxic waste; devices that instantly destroy chemical and biological weapons such as anthrax; improved computer chips; devices into which garbage can be thrown and recycled; and perhaps for generating a clean and unlimited supply of energy in the future through fusion — the energy source of the sun.
“We are doing pure research on fundamental issues such as understanding how heat and energy are transported through a plasma, and learning the structure of plasmas, but the payoff could be tremendous,” Gekelman said. “Understanding these fundamental issues could help enormously with designing and building better devices, including, perhaps, a better fusion reactor. Until we understand the fundamental science of plasma physics, it is like trying to cure a brain disease without knowing what part of the brain is involved. Transport, for example, is one of the factors preventing fusion from being a reality. If scientists understood transport, we could design more efficient fusion devices.”
Hydrogen bombs are plasma, and after the first hydrogen bomb was exploded, scientists realized an unlimited supply of energy could be tapped if we can control fusion, Gekelman noted. Efforts to do so in the 1950s failed, he said, because attempts to force enormous amounts of energy and enormous magnetic fields into small regions of space achieved not temperatures and conditions needed for fusion, but rather a violent, unstable plasma. Plasmas stick to magnetic fields and ride them like a cowboy on a bronco. The electrically charged plasma tore itself apart before fusion could occur.
“The problem,” Gekelman said, “was we didn’t understand plasma physics, and to a large extent, we still don’t.”
Plasmas are very odd. Remarkably, the temperature in a plasma within a magnetic field can differ tremendously in different directions.
“Looking one way from one particular spot, it could be a million degrees, while looking another way it could be only a thousand,” Gekelman said. “An analogy would be your face is at a million degrees and your shoulder is freezing.”
As they move through oscillating plasma, superheated and energized plasma waves can transform themselves and can change the properties of the plasma.
The Earth is too cold for plasmas to exist here naturally. “Plasmas start above the Earth’s atmosphere; a few hundred miles up, it’s all plasma,” Gekelman said. “From then on out, the whole solar system is filled with plasma.”
The Department of Energy and the National Science Foundation have initially funded the facility for five years. The predecessor to this machine was funded by the U.S. Navy. In addition to the $4.8 million to fund the UCLA national user facility, Gekelman’s research team has been funded $600,000 annually from the Department of Energy and the U.S. Navy to support their own research.
Gekelman, who has conducted research in plasma physics since earning his Ph.D. in 1971, built several earlier, less sophisticated devices for studying the behavior of plasmas.
Gekelman’s team includes research scientists Jim Maggs, David Leneman and Steve Vincena; technician Marvin Drandell; and Karen McBride, associate director of the Basic Plasma Science Facility.
In addition to conducting research and teaching, Gekelman has built the country’s only plasma physics laboratory for high school students, with funding from another DOE grant. Students and their teachers from some two dozen Los Angeles-area high schools conduct plasma physics experiments in this laboratory. Any high school can participate.
“The high school students use the same techniques we do, the same software and much of the same equipment (but not the new LAPD),” said Gekelman, who has worked with high school students in his lab for several years.