Broad Scientific and Societal Impact

Research at ZEUS promises advancements in medicine, national security, materials science, astrophysics, and fundamental plasma and quantum physics. Funded by the U.S. National Science Foundation, ZEUS operates as a user facility, allowing domestic and international research teams to submit proposals that are evaluated through an independent selection process.

Figure 1. ZEUS Fires Its First 2-Petawatt Laser Shot.

“One of ZEUS’s strengths is that it’s not just a single laser, but can split its light into multiple beams,” said Franklin Dollar, physics and astronomy professor at the University of California, Irvine, whose team is conducting the first 2-petawatt user experiment. “A national facility like this, which allocates time to the most promising experiments, is revitalizing high-intensity laser science in the U.S.” Figure 1 shows ZEUS Fires Its First 2-Petawatt Laser Shot.

Generating Particle Accelerator-Level Beams

Dollar’s team aims to produce electron beams with energies comparable to those from multi-hundred-meter particle accelerators—5 to 10 times greater than previous ZEUS experiments.

“We plan to achieve higher electron energies using two laser beams: one to form a guiding channel, the other to accelerate electrons through it,” said Anatoly Maksimchuk, U-M research scientist in electrical and computer engineering, who oversees the development of the experimental areas.

Innovative Target Design and Wakefield Acceleration

A key part of this effort is a redesigned target: the team extended the gas cell containing helium, into which the laser pulse is directed. As the pulse passes through, it strips electrons from the atoms, forming plasma—a mixture of free electrons and positively charged ions. The freed electrons are then pulled along in the wake of the laser pulse, much like surfers riding waves behind a speeding boat, in a process called wakefield acceleration.

Because light slows down in plasma, the electrons can catch up to the laser pulse. With a longer, less dense target, they have more time to accelerate before overtaking the pulse, allowing them to reach much higher speeds.

Toward Zettawatt-Scale Experiments

This demonstration showcases ZEUS’s capabilities and paves the way for a landmark experiment later this year, where accelerated electrons will collide with counter-propagating laser pulses. From the electrons’ perspective, a 3-petawatt laser pulse will appear amplified to the scale of a zettawatt—hence the facility’s full name: the “Zettawatt Equivalent Ultrashort laser pulse System.”

“The fundamental research at the NSF ZEUS facility has many potential applications, from improved imaging of soft tissues to advancing cancer treatment technologies,” said Vyacheslav Lukin, program director in the NSF Division of Physics. “By harnessing ZEUS’s unique capabilities, scientists will push the boundaries of knowledge and open new opportunities for American innovation and economic growth.”

The ZEUS facility occupies a space roughly the size of a school gymnasium. In one corner, a laser generates the initial infrared pulse. Diffraction gratings—special optical devices—stretch the pulse in time so that when the pump lasers add energy, it doesn’t become so intense that it ionizes the air. At its largest, the pulse measures about 12 inches across and several feet long.

After four rounds of energy-boosting by the pump lasers, the pulse enters the vacuum chambers. Another set of gratings flattens it into a 12-inch disk just 8 microns thick—roughly 10 times thinner than a sheet of printer paper. Even at this width, the pulse is powerful enough to turn air into plasma. It is then focused down to 0.8 microns wide to deliver maximum intensity to the experiments.

A Nimble, Midscale Facility

“As a midscale facility, we can operate more nimbly than large installations like particle accelerators or the National Ignition Facility,” said John Nees, U-M research scientist in electrical and computer engineering, who leads the ZEUS laser construction. “This flexibility draws innovative ideas from a wider community of scientists.”

Challenges in Reaching Full Power

Reaching 2 petawatts has required careful, deliberate effort. Even sourcing the necessary components has proven more difficult than expected. The most critical piece is a sapphire crystal infused with titanium atoms, nearly 7 inches in diameter, which serves as the heart of the final amplifier that brings the laser pulse to full power.

Source:SciTECHDaily

Cite this article:

Priyadharshini S (2025), America’s Strongest Laser Delivers its First 2-Petawatt Blast, AnaTechMaz, pp. 290