For the past 36 years, the Los Alamos Neutron Science Center has provided physicists worldwide with a unique user resource. And early this month, like clockwork, LANSCE resumed beam operations for another year, with a number of experiments waiting in the wings to provide researchers with important answers to fundamental questions.
But perhaps even more reliable than the steady stream of protons zipping along at nearly the speed of light within the pencil-thin, half-mile-long beam channel at LANSCE is the facility’s founder, Louis Rosen. As one of the Laboratory’s most distinguished scientists, Rosen continues to keep regular office hours at LANSCE despite having been retired for decades.
LANSCE will celebrate Rosen’s 90th birthday from 1 to 3 this afternoon at the auditorium that bears his name. Cake and light refreshments will help mark another vibrant year of life for Rosen, who spent much of the 1960s paving the political path for the proton accelerator.
Groundbreaking for LANSCE (formerly the Los Alamos Meson Physics Facility) took place in 1968 in the rocky soil atop a formerly nondescript mesa known as Mesita de Los Alamos. Just four years later, and after having spent the equivalent of $1 billion in today’s dollars that Rosen had secured from Washington for construction and startup, the LANSCE proton beam reached full energy of 800 million electron volts.
Through the years, LANSCE has helped researchers design better automobile engines, probe the intricacies of complex proteins, and answer some of the most basic questions about the world and universe we live in. Because LANSCE is an international user facility, anyone can write a proposal to set up an experiment at the facility during each annual run cycle. Competition for beam time is fierce.
Among today’s scientific users, the facility is more popular than ever. “This year we received 277 user proposals, which is the largest number of user proposals for a single call in the history of the Lujan Center,” said Alan Hurd, director of LANSCE’s Lujan Neutron Scattering Center, where protons slam into a tungsten target to provide experimenters with a steady blast of neutrons.
Hurd said about 300 materials researchers will have beam time at the Lujan Center for this year’s run cycle, which has begun and runs through mid December. A similar number of users are expected to utilize the Weapons Neutron Research (WNR) Facility.
In addition to experiments at the Lujan Center and WNR, LANSCE produces a steady stream of medical radioisotopes—a rare commodity for specialized medical research. Without LANSCE, the nation’s supply of such medical isotopes would be severely limited.
Getting the facility ready to deliver a reliable beam of protons throughout the run cycle is no trivial task. Much of the equipment at LANSCE is original. In many places along the beam line, you won’t find slick digital readouts, computer controlled adjustments or even a lot of integrated circuitry. Instead, toggle switches, plastic knobs, analog counters, and vacuum tubes dominate the array of controls running along the beam line.
“Getting a 36-year-old proton accelerator up and running presents its own brand of challenges, but the crew out here does a tremendous job making it happen,” said Hurd, who credited the Accelerator Operations and Technology (AOT) Division for an outstanding job.
This year AOT personnel began first preparations back in February, working at a feverish pace until they were ready to deliver the first trickles of beam in mid May.
Before that, AOT personnel repaired the front end of the accelerator, reconditioning the towering, picturesque stainless steel Cockcroft-Walton voltage multipliers, which provide the 750,000 volts of direct current necessary to start protons moving down the beam line.
But the start-up process doesn’t begin and end with equipment, Hurd said. The facility also pays special attention to safety.
“To ensure that LANSCE is safe, we go through numerous equipment readiness checks and instrument check-outs,” said Hurd. “In other words, at LANSCE we follow all the rigor of a startup of a nuclear facility, even though LANSCE is no longer categorized as a nuclear facility.”
In the coming years, LANSCE will continue with a refurbishment to bring the facility up to modern standards. In fiscal year 2010, the facility will replace the tungsten target where protons jar loose the neutrons that provide the basis for experiments at the Lujan Center. Other upgrades will make the facility more reliable and modern.
In the meantime, the spirit of pure science, accompanied by the very real Louis Rosen, continues to walk the hallways of LANSCE as it has for nearly four decades.
