World’s Sharpest X-Ray Beam Developed at DESY: 10,000 Times Thinner Than Hair Strand

A team of scientists has generated world's sharpest X-ray beam that is ten thousand times thinner than a human hair.

The X-ray  beam is five nanometers in diameter and was created by researchers from University of Gottingen.   This fine X -ray beam is expected to  accelerate materials research.

The team included Prof. Tim Salditt from the Institute for X-Ray Physics and Prof. Hans-Ulrich Krebs from the Institute of Materials Physics.

For this study, the researchers used the Fresnel lens instead of ordinary lenses as the high-energy X-rays cannot focus as easily as visible light with a magnifying glass. The central carrier was a fine tungsten wire, which was almost thousand millimeters thick. Around the wire were layers of nanometer-thin silicon and tungsten layers, applied alternately. Researchers then cut a thin slice from the coated wire, according to the press release.

The team explains, "On this disc is 50 to 60 silicon and tungsten layers draw like the rings of a tree disc... And whose thickness must be highly accurate."

The two-thousandths-of-a-millimeter-thick wire was used as a lens and it scattered the light, generating a pattern of dark and bright areas. They designed the thickness of the layer in such a way that the light areas of the diffraction pattern occurred at one point.

By adopting this technique the physicists were able to generate an X-ray beam of 4.3 nanometers in diameter in the horizontal direction and 4.7 nanometers in diameter in the vertical direction. Until the latest study, researchers weren't sure about whether fundamental limits of X-ray optics would work against the tiny focal widths, but DESY's X-ray source PETRA III has proved that it has a usable nanofocus reach.

"Normally you can, for example, in the study of the chemical composition of a sample only resolve structures that are larger than the beam itself In this experiment, the limitation still at about 20 nanometers," says DESY researchers Dr. Michael jump, who is in charge of the PETRA station P10.

The researchers plan to improve the technology and study nanostructures with their new ultra-fine jet.

The findings are documented in the journal "Optical Express."