Yale prepares for atom smasher’s farewell, sets stage for new physics era

Yale University has begun a multi-phase renovation of the former Wright Nuclear Structure Laboratory that will reinvent the landmark nuclear physics lab for a new era in physics research.

Expected to take at least three years, the project will transform the bunker-like home of what once was the world’s most powerful atom smasher of its kind into a site for teaching, research, and development related to two of the hottest topics in 21st-century physics — the study of neutrinos and the hunt for dark matter.

“This is the start of a new research effort,” said Karsten Heeger, the Yale physicist who directs the facility, recently renamed Wright Lab. “The nature of the place will change.”

Neutrinos are abundant subatomic particles that might help explain a mystery of the universe: why we live in a world of matter rather than anti-matter, although both exist in the laboratory. Dark matter is believed to make up as much as 85 percent of the universe’s matter, yet has never been directly detected.

Built in the late 1960s and originally known as the A.W. Wright Nuclear Structure Laboratory, the Wright Lab once housed the world’s largest university-based nuclear accelerator and was the site of major experiments in nuclear structure physics, nuclear astrophysics, and heavy ion physics. Wright alumni have risen to a variety of major posts in science and science policy, including founding director, D. Allan Bromley. He became President George H.W. Bush’s assistant for science and technology and director of the Office of Science and Technology Policy.

“The Wright Laboratory has a long tradition as one of the leading nuclear physics facilities in the country,” said Steven Girvin, Yale’s deputy provost for science and technology. “The important experimental discoveries and decisive tests of theoretical predictions achieved there in the second half of the 20th century fundamentally advanced our understanding of atomic nuclei and deepened our insight into the role of nuclear phenomena in important astrophysical processes such as star formation and evolution.”

From the start, the lab’s defining instrument was a nuclear accelerator, a massive device for generating and smashing high-velocity streams of atoms, allowing scientists to probe the nuclei of “hydrogen to gold and everything between,” said Jeff Ashenfelter, former director of accelerator operations.

The original machine, installed in the 1960s, was replaced in the 1980s by a larger, more powerful — 22 million-volt — version that could propel atoms at tens of millions of miles per hour. In 1987 Bush, then vice president, attended a ceremony at Yale marking the activation of that machine, a stand-alone tandem Van de Graaf accelerator.

By the late 2000s, accelerator operations began winding down as more powerful accelerators were built elsewhere and research interests shifted. The accelerator was shut off in the summer of 2011 and has not been used since, leaving the multi-level subterranean lab on Yale’s campus available for new purposes.

Researchers at the lab will develop new experiments that will take place at sites around the world.

“For the 21st century the lab is turning to the study and testing of fundamental symmetries in nature and to the physics of neutrinos,” said Girvin. “We are extremely fortunate to have been able to recruit Karsten Heeger to lead the lab in these exciting new directions.”

The first phase of the Wright Lab’s new life involves clearing the subterranean warren of old instruments. Much of this has already happened. Beam lines that channeled speeding atoms into detection chambers went to the University of Michigan. Some of the detectors themselves went to the Argonne National Laboratory in Illinois. Texas A&M will get a huge magnet. A giant spectrometer known as the “multi gap tank,” which looks like a massively magnified blue gumball, will be scrapped. Other choice relics may become part of the Yale Peabody Museum’s collection.

Removing the accelerator tank — imagine a bloated, blue mini submarine — represents a major task for the year ahead. With a volume of 39,000 cubic feet, it is more than 30 meters long and, with related equipment, occupies floor space of about 14,000 square feet. When it was installed in the 1980s, near the corner of Whitney Avenue and Edwards Street, the building was closed around it.

Heeger said the tank will most likely be cut apart and scrapped, unless a new home elsewhere is found soon. The U.S. Department of Energy owns the accelerator.

Before it vanishes, Heeger plans to open the tank for public viewing.

“This would be a rare opportunity for people to walk inside a nuclear accelerator and learn hands-on,” he said. “People will see what it takes to accelerate nuclei and atoms.”

Visitors have already demonstrated interest: During the inauguration festivities for Yale President Peter Salovey in October, about 200 guests toured Wright Lab. No one was able to go inside the accelerator tank itself.

Heeger said he expects the innards of the former accelerator lab to be completely removed by 2015. Initial renovation work began this month and will proceed in phases through the next two or three years at least.

He and his fellow researchers won’t be twiddling their thumbs meanwhile:  “We’re setting up temporary labs now,” he said.

Heeger and other Yale physicists are deep in the planning of a Center for Weak Interactions and Fundamental Interactions that would be based at Wright Lab. It will encompass experimental and theoretical studies on campus, foster collaborations with Brookhaven National Laboratory on Long Island and the National Institute of Standards and Technology in Maryland, and support new collaborations with scientists in the United States and overseas.

New neutrino and dark matter experiments led by Yale scientists are already underway.

“Things are changing very fast here,” Heeger said.

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