The world’s brightest X-ray machine, called the Linac Coherent Light Source II (LCLS-II) X-ray laser at SLAC National Accelerator Laboratory in California, has recently produced its first record-breaking X-rays. These X-rays will enable researchers to observe atoms, molecules, and chemical reactions in unprecedented detail.
The upgrade process for the LCLS-II began over a decade ago, and the X-rays it now generates are on average 10,000 times brighter than those produced by the original LCLS facility.
LCLS-II uses a complex process involving lasers, electrons, microwaves, and magnets to generate X-rays. Researchers first use an ultraviolet laser to remove electrons from a copper plate. These electrons are then accelerated using intense microwave pulses and guided through a maze of magnets, causing them to emit X-rays in controlled bursts. The resulting X-rays are a trillion trillion times brighter than those used in medical procedures.
The brightness of the X-rays produced by LCLS-II is due in part to the refurbishment of the metal tube through which the electrons travel. The tube has been lined with niobium, a metal that can withstand exposure to extremely energetic electrons when cooled to about -271°C. To keep the tube cool, a large cryogenic plant has been installed below ground.
Calibrating the maze magnets with extreme precision was another challenge faced by the SLAC team to ensure the correct shape of the X-ray pulses. Mike Dunne, a researcher at SLAC, states that every part of this system had to work together perfectly. Over the past 12 months, Dunne and his colleagues have been calibrating the machine and gradually increasing its power.
According to Nadia Zatsepin from La Trobe University in Australia, LCLS-II will enable researchers to capture “molecular movies” of biological processes at the atomic scale, such as mammalian vision, photosynthesis, drug binding, and gene regulation.
Dunne emphasizes that besides producing bright X-rays, LCLS-II can also generate a large number of X-rays in a very short time. This capability will allow researchers to study the internal properties of technologically important materials, including artificial photosynthetic devices and next-generation semiconductors. Additionally, LCLS-II’s X-rays could provide insights into exotic materials like superconductors and topological phases, which are not yet fully understood at the quantum level.
In summary, LCLS-II is a powerful scientific tool that can be applied in a wide range of fields, from quantum materials and biology to catalytic chemistry and atomic physics.
