The US tested its most powerful laser yet
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A laser named after the most powerful god in ancient Greece is living up to its name. According to University of Michigan’s Zettawatt-Equivalent Ultrashort Pulse Laser System (ZEUS), the first official test from this system yielded 2 Petawatts (2 Quadrillion Watts) of power. If you blink, you might miss the fact that this is more than 100-fold the amount of electricity produced on the planet. ZEUS’s debut demonstration required firing a pulse of laser light at a helium-filled cell. As the electrons were torn away from helium, the subsequent interaction created plasma. This resulted in a mixture both of positive ions as well as free electrons. In a phenomenon called wakefield acceleration, the electrons began to accelerate behind the laser pulse. The electrons are able to catch up with the laser beam because light travels slower in plasma. The free electrons have more time to accelerate due to the larger target chamber, and so reach higher speeds. The accelerating electrons in that test will also hit laser pulses coming the other way. This is where things get (even) more complicated–but to condense it down, the effect makes a 3-petawatt laser appear one million times more powerful, hence the “zettawatt-equivalent” in ZEUS’ name.
Accomplishing this and other experimental feats does require some safeguards. ZEUS uses optical devices called diffraction gratings to stretch out the infrared initial pulse over time. The ultimate goal is to create electron beams that have energies comparable to those of particle accelerators many feet longer than ZEUS, but at a fraction the size and cost. At only $16 million to construct, the University of Michigan previously described the machine as a “bargain.”
Years of construction, calibration, and expertise is showcased in an astoundingly short amount of time. ZEUS’s 2 petawatt firing lasted only 25 quintillionths a second. Future experiments will take advantage of these moments.
Johnny Nees and Paul Campbell, a laser engineer (left), work in Target Area 1 where the first user experiment of 2 petawatts will take place. Credit: Marcin Szczepanski / Michigan Engineering
“The fundamental research done at the NSF ZEUS facility has many possible applications, including better imaging methods for soft tissues and advancing the technology used to treat cancer and other diseases,” explained Vyacheslav Lukin, program director in the National Science d Division of Physics, which is responsible for the ZEUS project. Credit: Marcin Szczepanski / Michigan Engineering
“The fundamental research done at the NSF ZEUS facility has many possible applications, including better imaging methods for soft tissues and advancing the technology used to treat cancer and other diseases,” explained Vyacheslav Lukin, program director in the National Science d Division of Physics, which is responsible for the ZEUS project.
Meanwhile, ZEUS experiments could also help researchers explore the dynamics of positron jets that shoot out of black holes, or how gamma ray bursts operate. “One of the best things about ZEUS, is that it’s not one big laser hammer. You can split the beams into multiple beams,” Franklin Dollar, a University of California Professor of Physics and Astronomy, who oversaw this 2 petawatt experimental, said. The U.S. is gaining a lot of high-intensity science thanks to a resource such as this that awards time to those who have the most innovative ideas for scientific advancement.
