X-ray Beam

The purple light in this image comes from helium atoms excited by intense pulses of red laser light.  The helium also emits an invisible beam of X-rays - the first hint of an X-ray laser.

An Austrian-German collaboration, led by Ferenc Krausz of the Max-Planck-Institute of Quantum Optics, was able to create the laser-like X-rays using a technique currently in use to generate laser-like ultraviolet beams.  To make the jump to X-rays, the team had to increase the intensity of the red laser that excites the helium gas.

But boosting the intensity can rip the helium atoms apart before they emit any X-rays.  To overcome this challenge, the team had to use pulses of laser light only 5 millionths of a billionth of a second long.

The result is a narrow beam of X-rays that could one day improve the resolution in clinical X-ray images, as well as reduce the radiation dose to patients.

As of now, however, the X-ray beam delivered by the new source is too weak for any practical applications, but the researchers are confident that technical improvements will boost the power.

The results were published in a recent issue of Nature.

-- LiveScience Staff

Credit: J. Seres, Vienna University of Technology