Promising pulses

R w Schoenlein and his collaborators at the Lawrence Berkeley
Laboratory, US, have reported the
generation of ultrashort pulses of X-
rays using an infrared laser. The X-
rays have a wavelength of 0.4
angstrom and the pulse duration is
300 femtoseconds (one femtosecond
is 10-15 seconds). They scattered a
pulsed in(rared laser beam with a
tightly focussed electron beam to
create theX-ray pulses. Though the
amount ofX-rays ( the flux) is small,
the technique is promising and
could result in the development of a
new source of ultrashort X-ray
pulses with many applications
(Science, Vol 274, No 5285).