The Underground Tunnel Where the Laws of Physics Are Rewritten

By Andrew Tarantola on at

Thirty feet beneath the hills of Menlo Park, California, scientists at the Stanford Linear Accelerator have worked for the past half century to alter our fundamental understanding of the universe. The 1.9-mile-long structure, where electrons fly at nearly the speed of light, is reputed to be the straightest object on earth. Here's a peek inside.

The SLAC National Accelerator Laboratory is just west of the main Stanford University campus. While the accelerator's beam line is three stories underground, the 250-unit Klystron linear-beam vacuum tube gallery that powers it is located on the surface, housed in the longest building in the United States. In addition to the accelerator, the SLAC facitility also houses the Linac Coherent Light Source (LCLS), a free electron laser that utilises hard x-rays ten billion times brighter than traditional synchotron X-rays to take exceptionally detailed "snapshots" of atoms. The facility also contains the Stanford Synchrotron Radiation Lightsource (SSRL), used to study the structure of molecules for materials science and biology, and the now-defunct PEP-II electron-positron collider, which was originally used in the BaBar experiment.

The lab was founded in 1962, and by 1966, it was slinging particles at 99.9999999 percent of the speed of light. The researchers soon began making groundbreaking discoveries. In 1976, researchers at the facility discovered the charm quark. In 1990, a trio of scientists modeled the quark structure within protons and neutrons based on their research at SLAC. And in 1995, Martin L. Perl discovered the Tau lepton. All three of these discoveries earned a Nobel Prize in Physics.

Today, SLAC hosts 3,400 scientists from around the world. More than a thousand scientific papers are published each year based on their research. As part of the 50th anniversary celebration, Gizmodo was invited to tour the labs to take a look at what goes on down there.

Name: Stanford Linear Accelerator Center

Location: Stanford University, Menlo Park, California

Money Invested: £11,500,000 in preconstruction research and development; $£72,000,000 for design and construction.

Prized Possession: The 1.9 mile-long Linear Accelerator, the longest such device on the planet and one of the longest buildings on Earth. Six researchers have earned Nobel Prizes through their work at SLAC.

Theft Deterrent: The biggest deterrent could be obscure physics jargon. As Andy Freeberg, SLAC's Media Relations Manager, told Gizmodo:

We really have two different security areas. The area right when you enter is actually a pretty low security area. They check to make sure people are coming into the lab for a reason, but you don't need to be badged. However, to get back to the accelerator, LCLS and SSRL, you need to be badged and escorted. There are many pieces of equipment at SLAC that emit potentially lethal radiation levels so we obviously don't want people wandering around back there if they aren't familiar with the place.

The highest security is to protect places called radiologically controlled areas, or RCAs. For those, you are required to wear a dosimeter to go in. SLAC doesn't deal with nearly the radiation dangers of some of the labs that do nuclear work have to, but we monitor very closely and have lots of safety restrictions all the same. No one visiting or working at SLAC is exposed to any out-of-the-ordinary radiation levels and we've never had someone hurt by radiation, but when you have particles flying around and things being ionized at high energy levels, you're best off having significant security in place.

As for electronic security, if you're talking data/IT security, we actually aren't particularly secure. We're not the type holding government secrets, we're far more the types working on enormous collaborations and sharing data liberally. That's part of why, in 1991, SLAC had the first website in North America (brought over by physicists who worked with Tim Berners-Lee at CERN). And, now, that's why you see the Fermi space telescope sharing all of its data.

So, the security is really about safety, not about keeping secrets or keeping people out. We have really nothing to hide.

Geekiest Gear: The Facility for Advanced Accelerator Experimental Tests aims to improve the power and efficiency of particle accelerators. Using a process known as Plasma Wakefield Acceleration, electrons are pushed ahead of a wall of plasma, generating high-density positron and electron beams at 1,000 times greater energies over a given distance than what current technology can muster. Eventually, they could be scaled down for use in a wider variety of fields, the same way the microprocessor helped computers go from mainframes to PCs.

On the Wish List: SLAC isn't limited to just particle physics. The facility also performs extensive research on the galactic scale. To that end, SLAC is currently constructing the Large Synoptic Survey Telescope (LSST), the world's biggest digital camera. This wide-field reflecting telescope will be installed atop a Chilean mountain in 2014 and will survey the entirety of the Southern sky every few nights, snapping a 3.2 gigapixel image every 20 seconds.

Top art courtesy of SLAC


The beamline

High nickel-content metal wraps around the length of the beamline in order to shield it from the Earth's magnetic field

Magnets along the beamline

Heavy-duty magnets used to align the beam as it enters the LCLS.

John Bozek, LCLS Instrument Scientist, explaining the function of the LCLS

The Near experiment room (named because it is closer to the beam source than the Far experiment room)