The ZEUS laser, tucked away (as much as a giant laser can be) at the University of Michigan, just cranked out a pulse that makes it the most powerful laser beam in the country.
ZEUS’ peak power topped out at 2 petawatts, or a staggering 2 quadrillion watts, roughly 100 times the entire planet’s power output. Of course, that level of energy is fleeting; the pulse lasts just 25 quintillionths of a second—just enough time for researchers to do some pretty revolutionary science.
“This milestone marks the beginning of experiments that move into unexplored territory for American high field science,” said Karl Krushelnick, director of the Gérard Mourou Center for Ultrafast Optical Science, where ZEUS is housed, in a Michigan release.
ZEUS is short for Zettawatt Equivalent Ultrashort laser pulse System, and its power (at the risk of blasphemy) rivals that of the king of the Greek gods, who famously wields a lightning bolt as a symbol of his power. ZEUS is funded by the National Science Foundation, and scientists from around the world can apply to run experiments there—similar to the Linac Coherent Light Source II (or LCLS-II) at the SLAC National Accelerator Laboratory. Like LCLS-II—whose domain ranges from understanding photosynthesis and the cores of stars—the applications of ZEUS’ laser range from plasma and quantum physics to medical imaging, particle acceleration, and materials research.
“The energy of the individual photons in a pulse from LCLS is about 20,000 times greater than the photons from the ZEUS laser—but the peak power is 100,000 times lower,” Krushelnick told Gizmodo in an email. Krushelnick added that the use cases of ZEUS are manifold, but measuring physics at extreme intensities, the development of new radiation sources, laboratory astrophysics and imaging small-scale materials are a few of its principal scientific uses.
Franklin Dollar, a physicist at UC Irvine, will run the first 2-petawatt user experiment, aiming to produce electron beams with energies comparable to those from long particle accelerators. Should he and his team succeed, the electron beam energies will be between 5 and 10 times higher than any beams ZEUS has yet produced. ZEUS will accelerate electrons using wakefield acceleration, by which electrons essentially surf on plasma to accelerate to extremely high speeds.
“The quest for higher peak power lasers enables studies of the fundamental nature of light in the limit of extremely high instantaneous electromagnetic fields,” said Vyacheslav Lukin, program director in the NSF Division of Physics, which oversees the ZEUS project, in an email to Gizmodo. “Just as ocean waves begin to break and foam as they get higher, electromagnetic waves act differently when the light becomes very intense and the electromagnetic field gets extremely strong.”
The beam isn’t just powerful—it’s quite large. At its biggest, the laser pulse is one foot (0.3 meters) across and several feet long, according to the Michigan release. But the pulse is ultimately focused down to just 0.8 microns wide, to maximize the number of laser pulses available for experiments on ZEUS.
But the big show is set for later this year, when the facility will get a titanium-infused sapphire crystal that will increase the laser’s power to three petawatts. The crystal took nearly five years to manufacture and is about 7 inches (0.18 m) across. ZEUS’ electrons will smash into laser pulses from the opposite direction, increasing the experiment’s pulse to essentially zettawatt-scale in the frame of reference of the particle beam.
About 15 months of user experiments have already been conducted on ZEUS’ single petawatt laser, but now the facility is capable of hitting much more powerful energy pulses. With the new and improved laser, the team can better interrogate some of the universe’s most fundamental physics, with implications across the sciences.
