DURHAM, N.C. -- A record-setting Russian ultraviolet free-electron laser
(FEL) has begun operating at its new home at Duke University, where investigators
expect to harness it soon for medical research such as improved laser surgical
The device also is producing intense beams of gamma rays, which other physicists hope will help answer major questions in nuclear physics such as understanding thermonuclear processes inside stars like the sun.
The OK-4 optical klystron FEL, originally developed at the Budker Institute of Nuclear Physics in Novosibirsk, Russia, was moved to Duke in May 1995 to take advantage of a much more powerful 1.1 billion electron volt electron "racetrack" at Duke's Free-Electron Laser Laboratory.
After being reassembled and joined to the laboratory's electron ring, the OK-4 began producing ultraviolet laser light late on Nov. 13. Within two days, physicists had also induced the system to produce gamma rays by colliding the laser beam with the same electron beam that feeds it.
Duke's FEL Laboratory is funded by a U.S. Department of Defense program for advancing laser technology in medicine.
Free-electron lasers are like no others because they produce laser light by perturbing beams of "free" electrons that have been liberated from their normal bondage to atoms. Because electrons that provide the energy of other lasers are held within the structure of their atoms, such lasers can emit only a limited number of discrete wavelengths of light. FELs, in contrast, can be "tuned" to a large variety of different wavelengths. Also, FELs' beam pulse structures and power levels are extremely easy to manipulate.
FELs produce light by passing such free-electron beams through a series of magnets. As in all lasers, the energized electrons emit light, which is then amplified and concentrated into a sharp beam by rapidly bouncing the light between mirrors within an "optical cavity."
Contact: Monte Basgall