The HERCULES laser, a scientific instrument used to study particle physics that's housed in the University of Michigan’s Center for Ultrafast Optical Science, is getting a power upgrade after receiving a $2 million donation from the National Science Foundation. HERCULES currently holds the Guinness World Record for being the highest intensity focused laser, but this upgrade provides even more opportunity for advancement.
The laser can utilize this power for only fractions of a second, but the scale of this power is immense. To give the power a frame of reference, Anatoly Maksimchuk, a research scientist in CUOS, compared the laser’s power to all power available in the United States’ grid.
“The whole grid of the United States is only one terawatt,” Maksimchuk said. “With our laser, in one room, you have 300 terawatts. So compared to the whole grid of the U.S., it is 300 times more just in a single room.”
With the upgrade, HERCULES researchers hope to bump up the power to two to three times its current capacity — to 500 or 1,000 terawatts. To do this, they’ll replace outdated lasers, some of which are homemade. The laser industry has progressed since the time of these homemade lasers, and researchers can now order more advanced versions. With this new equipment, HERCULES can reach new heights of power and intensity.
Assistant EECS professor Louise Willingale specializes in performing experiments with the HERCULES laser. She looks forward to the new experimental opportunities the upgrade provides.
“We’re hoping that with the upgrade we’ll be able to design new experiments that weren’t possible before,” Willingale said.
One new experiment they will attempt is called “boiling the vacuum.” When a laser reaches an extremely high intensity and encounters a single electron, the two can collide in such a way that they’ll create particles out of nothing. The upgraded HERCULES is expected to mimic this environment so researchers will be able to better study this phenomenon.
HERCULES will also make exciting new ventures in particle acceleration — a process that propels particles to faster speeds. Alexander Thomas, associate professor of nuclear engineering and radiological sciences, compared this process to wave surfing.
“Replace the boat with a laser pulse, which pushes through plasma, which is like the water, and the electron beam is the person gaining energy, being dragged in by the wave,” Thomas said.
Particle accelerators can be hundreds of yards long, but the HERCULES laser can accomplish the same job in a few yards or less.
“You’re reducing something that’s three miles long to something that can fit on a tabletop that impacts all of science, and that’s pretty exciting,” he said.
Increasing the energy and intensity of the laser is only one feature of the upgrade. Thomas discussed another area of improvement: a higher repetition rate, which allows the laser to shoot out pulses more frequently. Originally, researchers would have to wait about a minute between the trials of their experiments. The laser’s new technology will shorten this waiting time and allow for more repetitions.
“In terms of experiment techniques, it opens up much more,” he said.
Rackham student Amina Hussein, a graduate research assistant in the College of Engineering, has been working with HERCULES for two years. She discussed how incredible it is to have the opportunity to operate the laser herself.
“Getting an upgrade in a group like this where we work as collaborators who use the system and also get to take some ownership of the chambers is a really cool opportunity that I think is unparalleled in other groups that might have similar systems,” Hussein said.
She is excited for what the upgrade will permit HERCULES to accomplish.
“It’ll just allow us to continue pushing the envelope and do cutting edge science with these laser systems that are rare in the world,” she said.