With its powerful linear accelerator and five state‑of‑the‑art experimental areas, the Los Alamos Neutron Science Center (LANSCE) at Los Alamos National Laboratory contributes to a range of national security goals. The world-renowned facility supports the Lab’s stockpile stewardship program, helps advance the science of medical radioisotopes, improves the understanding of hydrodynamics, and more.
LANSCE celebrated its 50th anniversary in June 2022. While many years have passed since the accelerator’s creation, it continues to serve the nation. “Since 1972, LANSCE has been the Lab’s major experimental science facility,” says Alan Carr, senior historian at the National Security Research Center, the Laboratory’s classified library and archives. “LANSCE underpins Los Alamos as a world-class scientific institution. This was true 50 years ago and is still true today.”
The father of LANSCE
In 1962, Lab physicist Louis Rosen proposed the creation of an interdisciplinary facility that would help secure Los Alamos Scientific Laboratory (as the Lab was then called) as a leader in nuclear technology. His proposed facility would be a place where science would meet the challenges of national security, including energy security, medicine, environmental stewardship, and nuclear nonproliferation. “Louis Rosen knew nuclear science played a key role in helping address these challenges,” says historian-archivist Madeline Whitacre.
Rosen was particularly interested in using a high-energy accelerator to study subatomic particles. The accelerator would use electrical fields to accelerate protons (positively charged subatomic particles) to then-unheard-of speeds. The beam of protons would be directed to various experimental areas, where it would smash into metal targets—a process called scattering, which results in neutrons that can be used for a variety of experiments.
“No one could guarantee it could be done,” Rosen said later. “And, in fact, people who really knew the game were betting we would fail.”
But the Lab director at the time, physicist Norris Bradbury, saw the value in Rosen’s proposal. At this point in the Laboratory’s history, many of the bright minds who’d come to Los Alamos during the Manhattan Project had returned to civilian life following the end of World War II. Rosen and Bradbury both viewed the promising facility as a way for Los Alamos to stay relevant and attract the next generation of great scientists. “I convinced myself that we had to do something really major in nuclear science if we were, on the one hand, to fulfill our obligations to support a strong nuclear weapons program and, on the other hand, to maintain the prestige and credentials that would permit us to attract the very highest caliber of scientific people,” Rosen said. And in 1985, he wrote, “Los Alamos, under the able leadership of Norris Bradbury, was seeking ways to diversify its contributions to the nation while enhancing its viability and vitality as one of the nation’s foremost national security laboratories.”
Of course, the facility Rosen and Bradbury envisioned was so abstract for the time that many people thought it wasn’t possible. “It takes people of extraordinary courage to stake their scientific future, their professional careers, on something that is really very risky,” Rosen later recalled to Los Alamos Science magazine. “But people do it all the time. They take the gamble and they may lose. But unless you take these gambles, you can never win.”
A dream and a gamble
By 1963, a proposal for what was originally called the Los Alamos Meson Physics Facility (LAMPF) was presented to the Atomic Energy Commission (AEC), which was the predecessor of today’s Department of Energy (DOE).
In March 1964, a scientific advisory panel, headed by Nobel laureate and former Los Alamos physicist Hans Bethe supported the proposal and recommended that such a facility be built “for the vigorous pursuit of the study of nuclear structure.” That same month an AEC special advisory committee recommended the facility be constructed at Los Alamos.
By December 1965, Congress authorized $1.2 million (the equivalent of nearly $11 million today) for the facility’s architectural and engineering design. The official groundbreaking was in February 1968, and construction began that October. The building’s costs would total $57 million, equivalent to more than $470 million today.
“I never doubted we’d get the facility built,” says Jerome Peterson, a professor at the University of Colorado who, with his experience working on the cyclotron in Boulder, was asked to help design some of LAMPF’s beam lines—the vacuum tubes that used electromagnetic pulses to speed and steer protons. “Louis was a master of manipulation. Not in a bad way, he just had a sense for how to get things done in the political sense. For example, when he received funding to examine the nature of rock, he used some of the money to excavate a trench line for a future accelerator beam. Because once the trench was built, why not finish the job?”
Once completed, LAMPF stretched for more than half a mile atop one of Los Alamos County’s many long, narrow mesas. In June 1970, the first section of the facility’s accelerator produced the first proton beam at 5 million electron volts (an electron volt is the unit of measurement for the kinetic energy of a proton accelerated from a state of rest). A year later, in June 1971, a proton beam with an energy of 100 million electron volts was produced. And a year after that, on June 9, 1972, the much-anticipated energy of 800 million electron volts was achieved, making LAMPF the most powerful linear accelerator in the world at that time.
A user facility
LAMPF was the first “open user” facility at Los Alamos, meaning scientists from across the country could harness its power for research. During 1974—LAMPF’s first full year of operation—the facility beam was part of 73 experiments on behalf of 331 scientists from 72 institutions.
For these experiments to be successful, the accelerator had to deliver full-energy beam, which means that the facility’s thousands of vacuum, radiofrequency, electronic, cooling, electrical, and control circuits all had to function properly. “If any one of them fails, the beam goes down, and sometimes diagnosing and repairing the issue can take hours, days, or even weeks in the worst cases,” explains LANSCE Director Mike Furlanetto. “That reliability has gotten better as we’ve improved the systems over decades, but even now we only deliver beam approximately 70 percent of the time that we plan to do so.”
John C. Browne, who would later become the director of Los Alamos, worked at Lawrence Livermore National Laboratory in the early 1970s and traveled to Los Alamos specifically to run experiments at LAMPF. “I started to do experiments when the beam reliability was very low,” he remembers. “I’d bring my equipment, and we might sit there all night waiting for the beam and it might not show up until 4 a.m., or it might not show up at all, so we’d go back to our hotel and wait.”
One of Browne’s favorite stories from the early days of LAMPF is when a well-known professor at Yale University asked to run an experiment at the last minute, and Browne’s team was bumped. “I went to Louis’ office and told him it wasn’t fair,” Browne remembers. “I said, ‘I know I’m a young scientist, but our project was reviewed, and my whole team is here.’ Louis looked at me and said, ‘I think you’re right.’ After he told the professor, Louis came to me with a smile and said my beam time was back on. But he cautioned, ‘Just don’t go near this guy for a while because you’re on the top of his you‑know‑what list.’”
The memory sticks out to Browne because as an open‑user facility, LAMPF was egalitarian—a place where the science and not the scientist mattered most.
Today, a user group manages proposals for beam time and ensures that scientists outside the Laboratory continue to have the opportunity to use the facility. “LANSCE has had a user group since the LAMPF days, which was another brilliant idea of Louis Rosen’s,” Furlanetto says. “By tying science at LANSCE to the broader community, we ensure that our science stays world-class and that we have a chance to recruit the best students and postdocs to work at Los Alamos.”
Carr adds that “For 50 years, LANSCE’s main linear accelerator has provided unique capabilities to Laboratory researchers and external partners. The facility continues to support our national security mission as well as basic research and development.”
LANSCE’s many uses
In 1995, LAMPF was renamed the Los Alamos Neutron Science Center, or LANSCE, with the new name meant to be more reflective of the broad range of neutron science topics that the facility had come to support. Today, LANSCE’s proton beam is delivered to five state‑of-the-art experimental areas, a capability that makes the accelerator stand out among its peers.
“LANSCE is unique in that many accelerators have just a single mission focus,” says Los Alamos Director Thom Mason. “With five areas, we can work on many different types of complicated problems across scientific fields. At LANSCE, our research program in nuclear physics and materials science, as well as our fundamental science and medical isotopes programs, are as essential today as they have ever been.”
Isotope Production Facility
Starting from the accelerator’s injector system and traveling east, the proton beam’s first destination, traveling at just over 100 megaelectron volts, is the Isotope Production Facility, a key facility within the Department of Energy’s Isotope Program and part of a tri-lab effort with Brookhaven and Oak Ridge national laboratories. In April 2020, as facilities shut down during the pandemic, LANSCE started the beam up ahead of its normal run schedule to fill a supply chain gap and deliver critical supplies of the isotope strontium-82, which is used in heart imaging, and the isotope germanium-68, which is used in cancer diagnostics.
The Isotope Production Facility excels in the basic science and applied engineering needed to produce and purify useful isotopes that can then be produced at scale in the marketplace. In the fight against cancer, recent and current clinical trials are yielding promising results with the short-lived isotope actinium-225, which delivers high-energy radiation to a cancer tumor without greatly affecting the surrounding tissue. The isotope can be chemically modified to target certain cancers—prostate cancer, colorectal cancer, melanoma and others—that produce a distinctive antigen.
“Unfortunately, almost everyone is affected by cancer, themselves or the people they know and love,” says Kirk Rector, the Los Alamos point-of-contact for the DOE Isotope Program. “That’s part of what makes the work around actinium-225 for cancer in particular very exciting. The results from clinical trials using actinium-225 to treat even late-stage prostate cancer suggest that it could be a pretty significant way to attack that horrible disease.”
New Los Alamos research indicates that actinium-225 may also be effective against bacteria, especially important in an age of increased antibiotic resistance.
Ultracold Neutron Facility
Powered up to 800 megaelectron volts, and now traveling at 84 percent the speed of light (over 250 million meters, or almost 20 laps around the Earth per second) the proton beam can be delivered to four more areas, each more than a half mile from the injector system.
At the Ultracold Neutron Facility, protons are cooled to near absolute zero, about minus 460 degrees Fahrenheit, so that the basic properties of particles can be explored. Last year a research team measured the lifetime of a neutron with the most precision ever, finding that a lone neutron lasts for 877.75 seconds before disintegrating. Those precise measurements can impact the search for physics beyond the standard model—helping unlock the mysteries of new particles, even dark matter. The results could also advance understanding of the abundance of nuclei in the early universe and the formation of elements.
Proton Radiography Facility
LANSCE also helps researchers evaluate the reliability of the nation’s nuclear weapons stockpile. The most recent full-scale nuclear test conducted by the United States took place in September 1992. As the nation moved away from nuclear testing, additional facilities were needed to understand and certify stockpiled nuclear weapons.
LAMPF veterans working at LANSCE rose to that challenge. In the mid-1990s, they invented proton radiography (pRad), a new technique for imaging the insides of explosions while they occur.
“Even the data from those early pRad experiments impacted decisions relating to our nuclear stockpile,” Furlanetto says. “The ensuing 25 years of data have made major impacts on our understanding of stockpile science and nuclear counterterrorism.”
At LANSCE, America’s scientists are able to examine individual parts in weapons under high explosive blasts, using the pRad Facility to take videos of the results. LANSCE has also helped scientists understand the point at which fusion occurs and becomes self-sustaining, which became vital to fine‑tuning the codes that scientists use with supercomputers to digitally replicate the physics of our nuclear weapon performance.
“There were certain computer models that worked well to explain how nuclear implosions worked,” Browne says. “But with LANSCE, and abilities like those offered by pRad, we could watch in real time what happens. The modeling people were ecstatic because they had something that could verify their codes.”
Lujan Neutron Scattering Center
At the Lujan Neutron Scattering Center, another user center at the end of the main proton line, a neutron beam is produced that can offer the microstructural characterization researchers need to probe the properties of materials and learn how they react under different conditions.
For example, Los Alamos scientists have probed aging plutonium in pits, key components of nuclear weapons, at the atomic level to ensure they function properly and to learn more about their material properties. This capability has become especially relevant as the Laboratory is currently working to produce 30 plutonium pits a year, all of which will be made from existing pits that are decades old.
“Understanding materials as they age, along with their interaction with neutrons, represents a key challenge to our physical understanding of weapons as we continue to ensure the safety and effectiveness of the aging nuclear stockpile,” says Bob Webster, deputy Laboratory director for Weapons. “The essential data we gather at LANSCE through real-world experimentation complements the modeling and simulation integral to stockpile stewardship.”
Weapons Neutron Research Facility
The benefits of that data extend beyond the national security mission. For instance, at the Weapons Neutron Research Facility, obtaining the right safety measurements for criticality—the point at which a fission reaction becomes self-sustaining—are crucial data not only for key Laboratory activities but also for the nuclear industry overall. Understanding the physics properties of materials, including radiation effects on reactor components, helps ensure the safety of civilian reactors and the people who operate them.
The capabilities of the Weapons Neutron Research Facility also mean LANSCE is the premier and only U.S. facility for electronics testing and certification with neutron beams—technology that is applied to avionics, vehicles, medical devices and more.
Improvements enhance capabilities
Recent upgrades at LANSCE ensure that the facility remains relevant in the coming decades. For example, the spallation target (the source of neutrons) at the Lujan Center was improved. In the process, the system was redesigned to enhance its performance. In doing so, the Lujan Center is now able to study the kiloelectron volt range, a new energy regime for nuclear physics.
Across the accelerator, teams are replacing old electrical components with newer and safer components. Additionally, in keeping with the Lab’s broader sustainability initiatives, systems that use greenhouse gases are being replaced.
“The improvements and the investments we’re making result in a safer machine able to do better science,” Furlanetto says. “The kind of experiments we are able to do now were almost unimaginable when I joined the Laboratory 17 years ago, and I’m sure that in another 20 years we will be delivering even more exciting data.”
The accelerator is a complicated piece of machinery, and it takes a cross-organizational effort of more than 500 people—engineers, scientists, technicians, and others—to keep it performing. Those individuals are each committed to the goal of delivering science that tackles difficult challenges, whether enhancing national security, understanding the origins of the universe, or developing medicines that allow people to live longer and healthier. That work represents an abiding mission for the decades to come.
During a special event in September 2022, Los Alamos employees and distinguished visitors celebrated the 50th anniversary of LANSCE. Laboratory Director Thom Mason highlighted the multifaceted mission areas at LANSCE, from nuclear deterrence, to medical isotope production for medical imaging and therapy, to proton radiography.
“As you look at how this facility has evolved, one of the really striking things is the breadth of the programs supported here,” Mason said. “Accelerators are very versatile facilities, and if they’re well taken care of, they’ll grow and evolve and develop new capabilities over their lifetimes. LANSCE has evolved to do things that no one anticipated when it was built.”
For example, isotope production and proton radiography were not initially conceived of as part of LANSCE but have emerged as key capabilities. Isotopes are developed by the Isotope Production Facility for trials and then produced by private companies, and proton radiography technology provides crucial imaging data for the safe maintenance of the deterrent arsenal.
Furlanetto praised the hard work of the employees who contribute to the facility’s operations and achievements, an interdisciplinary endeavor that often means working nights, weekends, and even holidays to maintain the accelerator and meet production targets. “Though we have all this great equipment, what makes this place work is the people,” Furlanetto said. “They sacrifice to get data and research out and to make the world a better place.” ★