Applied mathematician wins DOE grant to improve the safety of particle accelerators

The Advanced Photon Source (APS) at Argonne National Lab.
The Advanced Photon Source (APS) at Argonne National Lab.
This figure shows scratches and other damage to the infrastructure of the APS after a whole beam dump.
This figure shows scratches and other damage to the infrastructure of the APS after a whole beam dump. (Emily Cerf)

UC Santa Cruz Professor of Applied Mathematics Dongwook Lee has won a three-year, $1.1 million grant from the U.S. Department of Energy, which will fund his research on improving computer models for safety mechanisms within particle accelerators. 

For this project, Lee will collaborate with scientists on the Advanced Photon Source (APS) Upgrade (APS-U) project at Argonne National Laboratory, the site of one of five of the U.S.’s ultra-bright light source facilities. These sites, called X-Ray Light Source user facilities, produce X-ray beams studied by scientists for a wide range of applications in medicine, biology, material science, astrophysics, and more. 

The APS facility at Argonne National Lab is donut-shaped, with beams of electrons shot out from a linear particle accelerator in the center. The beams are then bent by magnets to travel in circles around the site at very close to the speed of light. When the electrons bend, they emit synchrotron radiation in the form of very bright X-ray light.

Amid this process, at some point, the electron beams must be stopped. This is what scientists call a “whole beam dump,” and special breakers, which are called collimators and made of solid metals, are used to prevent the beams from damaging the facility and injuring its employees when that happens. As the collimators stop the beams, they get scratched and damaged. The ongoing technical upgrade of the APS is expected to result in very intense electron beams, which will increase the damage to the collimators as they encounter extreme high-energy-density conditions that impact machine protection.

The crux of this project is to study these processes and ensure the integrity and reliability of the collimators. Lee’s role will primarily be to develop high-fidelity numerical models for the physics of the whole beam dumps with the new APS-U system. In addition to researchers at Argonne National Lab, Lee will collaborate with RadiaSoft, whose physicists study accelerator particle physics as well as particle and material interactions. 

“Unlike many other typical proposals, this team has very unique expertise in different areas,” Lee said. “This project is a fine example of how applied mathematics can help advance real world problems.”

For the last two years, Lee has been working on preliminary research into the gas dynamics of this problem with the support of seed funding from Argonne National Lab. The project team includes Lee’s former Ph.D. student Youngjun Lee, who worked on the initial studies with the seed funding and is now a postdoctoral researcher at Argonne. The funding will also support a new Ph.D. student in the UCSC Applied Mathematics Department. 

Lee uses Flash-X, a popular open-source community code for astrophysicists and high-energy-density physics, to develop his computational models. As part of the project, the team will deliver and make publicly available the numerical code for doing this research, making it available to the research community for the continuation of this pioneering work. 

“We want to deliver our science with more clarity and more transparency in our effort,” Lee said.