Although sometimes lost in the background, many of the important breakthroughs in science are made possible by advances in scientific instrumentation. This is particularly and most obviously true for particle physics. For a while now, the big news in this area has been about the trials and tribulations of the Large Hadron Collider (LHC) in Switzerland. However, as they say, it’s not the only game in physics-town. Just coming on-line for research is the world’s most powerful x-ray laser device, and with it comes the promise of cracking many secrets of atoms and molecules.
The first experiments are now underway using the world’s most powerful X-ray laser, the Linac Coherent Light Source, located at the Department of Energy’s SLAC National Accelerator Laboratory. [Menlo Park, California]
After SLAC’s linac accelerates very short pulses of electrons to 99.9999999 percent the speed of light, the LCLS takes them through a 100-meter stretch of alternating magnets that force the electrons to slalom back and forth. This motion causes the electrons to emit X-rays, which become synchronized as they interact with the electron pulses over this long slalom course, thereby creating the world’s brightest X-ray laser pulse. Each of these laser pulses packs as many as 10 trillion X-ray photons into a bunch that’s a mere 100 femtoseconds long—the time it takes light to travel the width of a human hair.
The LCLS’s quick, short, repetitive X-ray bursts enable researchers to take individual photos as molecules move and interact. By stringing together many such images to make a movie, researchers will for the first time have the ability to watch the molecules of life in action, view chemical bonds forming and breaking in real time, and see how materials work on the quantum level.