NORMAL, Ill. -- Electrons racing about their atomic nuclei at nearly the speed of light bring new perspectives to the development of x-ray lasers. High-power, short-pulse lasers can coax electrons to yield x-rays, but they excite the electrons so much that the atoms can no longer hold onto them. A team at Illinois State University's Intense Laser Phys-ics Theory Unit, however, has theorized that a strong magnetic field and a laser orders of magnitude less intense can produce the same effects in a more stable system.
    The theory suggests that there is an alternative to the study of relativistic atomic electrons, but one that requires a large, static magnetic field, said Rainer Grobe and Qichang "Charles" Su, directors of the unit. They and their fellow researchers simulated the interaction of pulses from a 100-TW/cm² CO₂ laser and atomic electrons in a 1-kT magnetic field aligned to that of the laser. They predict in their report, which appeared in the April 10 issue of Physical Review Letters, that such a system could impel the electrons to speeds approaching 80 percent of the speed of light after a few cycles. It also could increase harmonic generation.
   

by Daniel S. Burgess