TRAPPED!

(continued)

The measurement of the helium-6 charge radius will be a key benchmark for all future few-body nuclear structure theories. The Physics Division's nuclear theory group is using this data to predict the size of the helium-6 nucleus using two different methods. These measurements require hundreds of hours using the JAZZ supercomputer in Argonne's Mathematics and Computer Science Division.
Lu readily admits the work he and his fellow physicists do can be hard to translate for a lay person. “It's not that the work we do is not important,” he stresses. “It's just that it's hard for people to relate to. But we believe what we do will have an impact on society, even the most esoteric research, but maybe not for 100 years.
“ Determining the charge radius of helium-6 is a small but important step toward reaching the goal of finding the way to describe the force that binds nuclei together,” Lu said.
Lu, who has been at Argonne since 1997, finds the pursuit of these small but important challenges personally gratifying. “I always enjoy learning simple, elegant ways of nature,” he says. “In physics I find plenty of such joy, whether I learn a great idea or discovery while attending a lecture, reading a paper, talking to colleagues or through my own work in the lab.”
Next Steps
In the near future, the collaboration hopes to tackle helium-8, which is the most neutron-rich matter on Earth. Preliminary testing began in February with experiments at ATLAS to determine the best combination of beam and target material.
Mueller will lead the helium-8 project. And since his appointment at Argonne was about to end, it was a great relief to all when he was named Argonne's Willard Frank Libby Fellow this spring, earning a new two-year appointment at the lab. Argonne offers special postdoctoral fellowships like this one to encourage the development of outstanding young researchers with promising careers. The fellowships are named after scientific and technical luminaries who have been associated with the laboratory, its predecessors and the University of Chicago since the 1940s.
According to Lu, Mueller has been an integral part of the helium-6 project from the beginning, and conducting the next experiment involving helium-8 without him would be next to impossible. “Li-Bang and Peter built this system,” Lu says.
“ Argonne provides a good working environment,” Mueller said. He especially enjoys his collaboration with Lu and looks forward to working on projects that will have an impact not just on one small specialized area, but on the field of physics as a whole.
“ In the last century, we learned to understand atomic structure very well,” Lu said. “Atoms we can calculate to exceedingly high precision using quantum mechanics and electromagnetic theory. But our understanding of nuclear forces is still growing rapidly. And I hope that in this century, we'll be able to solve this part of the mystery.”
Funding for this project was provided by the U.S. Department of Energy's Office of Nuclear Physics.