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Jefferson Lab doubles particle accelerator capacity

May 12, 2018

NEWPORT NEWS, Va. (AP) — Enter what looks like an industrial garage on the Thomas Jefferson National Accelerator Facility campus, make your way about 25 feet underground and you’ll find yourself standing in the midst of scientific history.

Under the hum of massive machines that intricately weave a jumble of colorful wires and metal tubes, millions of sub-microscopic particles jump and race, colliding with others at nearly the speed of light.

This symphony of science is orchestrated by the nuclear physicists at what’s known commonly as Jefferson Lab, and they are using newer technology than ever before.

The lab recently completed a $338 million overhaul to its central feature, the Continuous Electron Beam Accelerator Facility, doubling its energy capacity. Scientists say that will allow them to probe deeper into the elements of matter, discovering things about our universe no one has yet had the ability to see.

The accelerator, located underground to shelter it from the elements and vibrations of passing traffic, is a sort of racetrack for electrons.

But first, a refresher.

Everything in the universe is made up of tiny units of matter called atoms. In the center of an atom is its nucleus. In the center of the nucleus hover protons and neutrons; electrons circle around them. Further still within each of those particles are tinier ones called quarks.

Those are the fundamental building blocks of life that Jefferson Lab’s scientists want to better understand.

The lab sitting on 110 acres off Jefferson Boulevard is one of 17 around the country run by the U.S. Department of Energy. With 1,600 researchers who drift in and out, it’s “the largest nuclear physics user scientist community in the world,” said Allison Lung, manager of the upgrade project, which took more than a decade from start to finish.

Nuclear physicists send electrons into the accelerator at 12 giga-electronvolts. Before the recent upgrade, it was 6.

What does the electron do in that tube?

Nothing, really. It just goes around and around, gaining energy — which means it gains mass, if you remember your handy Einstein equation, e=mc. Think of it like an accelerated workout for the electron, during which it bulks up and becomes a trillion times more powerful than sunlight.

“We take a marble and turn it into a bowling ball,” said Kandice Carter, a lab spokeswoman.

After up to five laps around the tube, it’s big enough to research, and gets spit out at one of the four experimental halls.

Millions of electrons move through the accelerator at a time, in a beam the width of a human hair. Scientists carefully steer the string around the track using magnets.

The equipment is cooled to about -456 degrees Fahrenheit — near absolute zero — to reduce friction.

The accelerator runs continuously from the fall season through May, stopping during the summer so as not to draw too much on the local electric grid, Carter said. It collects 34 trillion bytes of data per day, fed to an aboveground control room where researchers run the equipment.

When the accelerator is running, no one is allowed in. Radiation inevitably created by the nuclear interactions is way too strong.

So what are researchers studying, anyway?

Once the electrons come out of the accelerator, they collide with other materials in large systems called detectors in the experimental halls. The materials could be as light as helium gas or as heavy as gold, Lung said. Scientists then observe the way the particles interact with each other.

One of the main questions scientists are trying to answer: Why can’t a quark ever be by itself?

The quarks are clustered in twos and threes, and when researchers try to force them apart, they form anew. The conundrum is called quark confinement.

“For the first time we have the ability to probe beyond the quarks and understand the strong force that’s holding those quarks together inside each proton and neutron,” Lung said. “Many other fields of science make assumptions about what quark behavior is. Our job is to get in there and find out if those assumptions are correct or not.”

Other goals include capturing the first 3D images of protons and neutrons and studying what scientists call the “glue” carrying force between quarks.

The new energy capability, coupled with other new equipment, makes the lab in Hampton Roads’ backyard “the only place in the world where this science can be done. Period.”

So says Latifa Elouadrhiri, a senior staff scientist. She said they already had a theoretical framework, but the upgrade gives them the ability to test their theories. Nine years of experiments are already planned.

For those in nuclear physics, “this is the newest aircraft carrier or submarine,” Stuart Henderson, Jefferson Lab’s director, told a crowd 2 that gathered to celebrate the milestone on May 2.

But why should you care?

“Part of it is our scientific curiosity, part of it is we want to understand what our universe is made of, and the other part is what can we do with it,” Carter said. “That’s why we’re here.”

Discoveries made by the lab can later translate to real-world uses. But as physicist David Lawrence put it, “it’s like asking Ben Franklin to predict the iPhone.” You need his understanding of electricity to make the phone, but it takes some time in between.

The lab has previously, for example, licensed out technology to a company that uses it for breast imaging on the molecular level, helping with early cancer detection. Lung said she’s gone to the hospital for a mammogram before, only to see the same detector that she’d been calibrating over at the lab.

“Our community is very proud of that,” she said.

As for the more general implications?

“It could change our understanding of the universe,” Lung said.

Seems like a pretty good place to start.


Information from: The Virginian-Pilot, http://pilotonline.com

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