WHAT THE WORLD'S MOST POWERFUL X-RAY LASER WILL DO FOR SCIENCE

DEEP UNDER MENLO PARK, California, there is a threemile-long machine operating in a tunnel that scientists are keeping colder than even some of the deepest reaches of space.

- Robert Lea

Maintaining this patch at a temperature of -456 degrees Fahrenheit around 3 degrees higher than absolute zero, the hypothetical temp at which all atomic movement stops-allows scientists at the Department of Energy's SLAC National Accelerator Laboratory to operate the world's most powerful x-ray laser, the Linac Coherent Light Source (LCLS) II.

The LCLS-II laser produced its first high-energy radiation beams on September 12, 2023, ushering in an exciting new era of x-ray-based research.

When at full power, LCLS-II will be able to pump out around a million x-ray pulses per second, about 8,000 times more than its predecessor. This means LCLS-II can create an x-ray beam 10,000 times brighter than the original LCLS, making it the most powerful x-ray laser ever devised.

"LCLS-II represents quite a significant adjustment or paradigm shift for science," says the laser's project director, Greg Hays.

Thousands of researchers are eager to conduct research with the experiment, but what exactly do scientists need such a powerful x-ray laser for?