'Lasetron' Promises Ultrafast Pulses, Strong Magnetic Fields

Laser light could help scientists observe the mysterious strong-force reactions responsible for holding the nucleus of an atom together, but these occur on the timescale of about 10^-21 to 10^-22 s -- rendering today's fastest lasers five orders of magnitude too slow. It may come as no surprise that researchers working with some of the world's most powerful lasers expressed interest when Alexander Kaplan from Johns Hopkins University in Baltimore and Peter Shkolnikov at the State University of New York at Stony Brook devised a tool called a "lasetron" that would use a high-power laser to cause electrons in subwavelength-size particles to break free and emit zeptosecond pulses.

Shkolnikov said several lasers are being constructed that could generate the required petawatt beam; however, there are no negotiations for the device's implementation. Instead, the designers expect that lower-power lasers will be used within two years to investigate the ~10⁶-T magnetic field predicted to accompany the lasetron's effect. The field should resemble those of astrophysical objects such as white dwarves. The physicists described the lasetron in the Feb. 18 issue of Physical Review Letters.