Free-Electron Laser Hits Record / FEL Potential Has Corporations Footing Part of Tab (Richmond Times-Dispatch)
A readout showed the Free-Election Laser was well on its way to setting a new 155-watt world record.
Free-Electron Laser Hits Record / FEL Potential Has Corporations Footing Part of Tab
By A. J. Hostetler, Richmond Times-Dispatch
June 18, 1998
One of the most powerful lasers ever built achieved first light yesterday as physicists at the Thomas Jefferson National Accelerator Facility herded millions of electrons through a maze of magnets.
The Free-Electron Laser broke the world's record for its kind, hitting 155 watts and surpassing the 11-watt mark held by Vanderbilt University for the past several years. The Jefferson team's goal was only 100 watts.
"It exceeded what it actually should be doing," said Dr. Hermann Grunder, Jefferson Lab director, as the laser team took a champagne-fueled break late in the afternoon.
The laser did so well that the project's leader, Dr. Fred Dylla, wasn't ready with plans of what to do next. Plans for a party, however, were already complete: the team will celebrate today with a cake inscribed, "Many hands make light work."
The FEL uses the electron to produce one of the most powerful and controllable light sources ever. At full power, the FEL will be about a million times more powerful than supermarket laser scanners.
Laser stands for "light amplification by stimulated emission of radiation." A laser beam is a concentrated beam of light confined to a single wavelength. The Jefferson FEL emits infrared light at five microns, so its beam can't be seen by the human eye, which sees only light at 0.7 microns, Dylla said.
Instead, the light shone yesterday was viewed on computer screens that showed a rainbow -- yellow, green, blue and red -- wrapped around the hair-thin beam emitted by the FEL.
The commercial potential for the Jefferson Lab FEL has corporations such as DuPont and Northrup Grumman so interested that they are helping the federal and state governments pay the laser's $34.2 million price tag. Potential uses for the laser include making food packaging resistant to bacteria, improving airplane speed and preventing metal corrosion.
Potential clients are willing to pony up major money because the FEL offers industry two major advantages over other tools: the FEL can cut through material faster and more accurately and it can easily alter the surfaces of materials, such as ceramics, metals and plastics, in a way that either can't be done today or is too costly.
|At right, Kevin Jordan (seated right), the project's electronic systems manager, and George R. Neil (seated left), the deputy program manager, and other staff and visitors watched the record being set.|
Commercial clients, including Virginia Power, are scheduled to begin experimenting with the FEL next month, Dylla said.
Fewer than two dozen FELs have been built since it was invented in 1977. A dozen others are under construction. The laser group at Jefferson Lab won financial support from governmental and industrial sources in part because its FEL uses some of the same components as the lab's particle accelerator, helping to shave $10 million off the project's costs.
Light production begins at the laser's injector, located underneath a two-story building not far from the particle accelerator. An electron gun shoots 40 million bunches of electrons per second into a 60-foot-long column.
The column is chilled in a superconducting chamber to minus 456 degrees and revs up the electrons to 40 million volts each before spewing them out at nearly the speed of light.
These supercharged electrons are then "wiggled" by a series of magnets so that they lose some of their energy. That energy is released as extremely intense light.
The laser beam, initially about a half-inch in diameter, is reflected out of its underground chamber and into any two of the six laboratories in the two-story building. Mirrors along the beam's path can change the size of the beam and magnets can change its wavelength.
The project is beginning with infrared light, but in a few years, the team hopes eventually to produce the more powerful ultraviolet light.
The laser is the practical, commercial side of the Jefferson Lab's $300 million particle accelerator, which aims hair-thin beams of electrons at various atoms to learn more about quarks, which make up protons and neutrons.
Construction on the FEL at the Jefferson Lab began just two years ago and ended last October. Physicists spent the past nine months putting the beam through its paces and checking the hardware. Last Friday, Dylla declared the beam ready, and by Monday, the team was revving it up.
For additional information, please visit https://www.jlab.org/FEL/