• Number 302  |
• December 21, 2009

Perseverance, stopping power, and Yanwen Zhang

Bombarded by ions travelling millions of miles a minute, some materials stop the ions quickly, but not others. For designers of nuclear reactors, radiation detectors, and electronics on satellites, knowing a material’s stopping power is key. For years, the speed and size of ions made measuring this phenomenon difficult. That’s where Dr. Yanwen Zhang at the Department of Energy’s Pacific Northwest National Laboratory stepped in.

Working at DOE’s EMSL, a national scientific user facility at PNNL, Zhang’s persistence in studying ion collisions led her and her colleagues to devise a novel approach to measuring a material’s stopping power. The method uses high-resolution, time-of-flight spectroscopy to measure the ion’s speed before and after passing through a thin film of atoms. With these measurements, scientists can determine stopping power.

These measurements are guiding studies on reactions inside nuclear reactors, where energetic ions are the primary mode of energy dissipation, and could aid in maintaining today’s reactors and designing tomorrow’s. Cosmic radiation, another form of energetic ions, is a vital consideration in designing electronics to help explore space.

Throughout her research, Zhang has garnered several awards, including a 2005 Presidential Early Career Award for Scientists and Engineers. She has also written 120+ articles, given numerous presentations, and led high-profile projects and collaborations. 

“Her perseverance and her intellect will continue to lead her into exciting discoveries,” said her manager Theva Thevuthasan.

Submitted by DOE's Pacific Northwest National Laboratory