X-ray

  • High-speed camera snaps bio-switch in action

    The riboswitch 'button' before, during and after coupling of the ligand (green), from left to right. Credit: Yun-Xing Wang and Jason Stagno, National Cancer Institute

    X-ray experiment opens new route to study biochemical reactions. With a powerful X-ray camera, scientists have watched a genetic switch at work for the first time. The study led by Yun-Xing Wang from the National Cancer Institute of the U.S. reveals the ultrafast dynamics of a riboswitch, a gene regulator that can switch individual genes on and off. The innovative technique used for this investigation opens up a completely new avenue for studying numerous fundamental biochemical reactions, as the team reports in a fast-track publication in the journal Nature.

  • Scientists shrink electron gun to matchbox size

    A miniature electron gun driven by Terahertz radiation: An ultraviolett pulse (blue) back-illuminates the gun photocathode, producing a high density electron bunch inside the gun. The bunch is immediately accelerated by ultra-intense single cycle Terahertz pulses to energies approaching one kilo-electronvolt (keV). These high-field optically-driven electron guns can be utilized for ultrafast electron diffraction or injected into the accelerators for X-ray light sources. Credit: W. Ronny Huang, CFEL/DESY/MIT

    Terahertz technology has the potential to enable new applications.In a multi-national effort, an interdisciplinary team of researchers from DESY and the Massachusetts Institute of Technology (MIT) has built a new kind of electron gun that is just about the size of a matchbox. Electron guns are used in science to generate high-quality beams of electrons for the investigation of various materials, from biomolecules to superconductors. They are also the electron source for linear particle accelerators driving X-ray free-electron lasers.