Plotting plasmas could influence fusion
Posted July 31, 2007
What Russel Caflisch does is like trying to grab a handful of fire.
Caflisch, a mathematician at the University of California at Los Angeles, is creating computer simulations of plasmas – clouds of ionized gas sometimes referred to as the fourth state of matter.
Plasmas are in neon lights and lightning. High-temperature plasmas
are at the heart of stars – and of proposed nuclear fusion
reactors, touted as clean energy sources for the future.
Computer simulations are critical to developing fusion because high-temperature plasmas are difficult to measure experimentally. Reactions take place in millionths of a second, at temperatures in the millions of degrees – much too high for most instruments.
With simulations, “You can see everything that’s going on,” Caflisch says. “You can slow it down artificially and you also can test things you wouldn’t be able to easily test experimentally.”
Simulations also can cost orders of magnitude less than experiments, he adds.
But computer simulations often run too slowly and produce unreliable results. “You’ll see that even today,” Caflisch says. “Two different simulations might give quite different results.”
To change that, Caflisch and his fellow researchers must bridge huge spans of space and time. They must combine mathematical methods depicting the tiniest particles with those depicting whole plasma clouds.
