- News Home
17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
Fusion Research Gets a New Squeeze
6 April 2000 7:00 pm
A new technique brings scientists closer than ever to harnessing the power of fusion, the process that fuels the sun. A fusion reactor is still a long way away, but tests bode well for a new way to contain fusion's fuel, hydrogen plasma.
Unlike starting fission reactions, which need only a minor nudge to get going, fusing hydrogen atoms is a very difficult task. Hydrogen nuclei repel each other, so the plasma that contains them must be very dense and very hot for the nuclei to collide strongly enough to fuse. Tokamaks--doughnut-shaped magnetic bottles--have long been the method of choice for maintaining a hot, dense plasma, but even the doughnut's magnetic fields need help in keeping the hydrogen atoms from drifting away and dissipating the plasma.
Now plasma physicists led by Olivier Sauter of the Swiss Federal Institute of Technology in Lausanne have shown that there is a better way to keep hydrogen atoms swarming together than the method currently being used at tokamaks. In a process called electron cyclotron current drive, the researchers point microwave beams at the plasma. The microwaves are tuned to the speed at which electrons in the plasma spin in the vertical plane. By controlling the angle of the microwaves, scientists can give an extra kick to electrons moving in one direction around the magnetic torus, which in turn induces a current around the doughnut and keeps the hydrogen atoms in the plasma from drifting apart, the researchers report in the 10 April issue of Physical Review Letters.
"It's very significant that they actually made it work," says Frank Skiff, a plasma physicist at Iowa State University in Ames. The big hurdles for fusion projects are political, however, as governments around the world have been scaling back their fusion programs in recent years. Compared to confining plasma, mustering political support for fusion research "is a much more difficult task," Sauter says.