New Code Connects Microscopic Insights to the Macroscopic World
While conducting his Ph.D. in mechanical and aerospace engineering in residence at Lawrence Livermore National Laboratory, or LLNL, through the University of California, Davis, recent alum Tim Linke led the development of a new framework that couples tiny, atom-scale simulations to code that describes the macroscopic world, all within the same simulation.
“We're talking about atoms on the order of nanometers versus, on the other hand, large flow fields on the order of meters,” said Linke. “The connection between those two lies in the material.”
In inertial confinement fusion, a capsule of fuel begins at temperatures near zero and pressures close to vacuum. When lasers compress that fuel to trigger fusion, the material heats up to millions of degrees and reaches pressures similar to the core of the sun. That process happens within a miniscule amount of space and time.
To understand this process, scientists need to know about the large-scale conditions, like temperature and pressure, throughout the target chamber. But they also want detailed information about the material — and the atoms — contained within. Until now, computer models have struggled to bridge that gap across the wide range of conditions encountered in such experiments.
Running the new framework, described in a recent study published in Physical Review E, requires massive computational power. The type, Linke says, that is only available at a national laboratory. Linke feels extremely fortunate to have been able to leverage the relationship between UC Davis and LLNL to pursue this research.
“The work would not have been possible without access to the supercomputer that they have, which is the most powerful in the world, and UC Davis researchers have access to it. That's amazing to me,” he said. “Collaborating with a place like LLNL is just a fantastic opportunity to expand on what a graduate student experience can be.”
For this research, Linke collaborated with LLNL scientists and was advised by Jean-Pierre Delplanque, professor of mechanical and aerospace engineering and the vice provost and dean of graduate studies at UC Davis.