In the 25 years Ka-Ngo Leung has worked at Berkeley Lab, he’s pursued alternative energy sources, helped fabricate innovative microelectronics and medical devices, explored ways to expedite DNA sequencing, and helped make oil-well logging more efficient. In the future, he may even help explore Mars.

	Berkeley Lab’s portable ion source uses neutrons to peer inside luggage and shipping containers to determine if explosive and fissile materials lurk inside.

What do all of these technologies have in common? Not much, except they can all can be improved by cutting edge research conducted at Berkeley Lab’s Accelerator and Fusion Research Division. Here, Leung and colleagues develop ways to harness plasma, a highly ionized gas found in interstellar space, the sun, and, here on Earth, in laboratories like those run by Leung’s Plasma and Ion Source Technology Group.

His group develops ways to extract ion beams from plasma generators. He can wield these ion beams like a tiny lathe, milling intricate arterial stents and electronic components. Or, when coupled with special equipment, he can use ion beams to produce neutrons that can determine the chemical makeup of whatever lies hidden inside shipping containers and luggage, or deep underground.

How did Leung learn to coax ion beams from plasma, and put them to so many different uses? He was always interested in science as a student in Hong Kong. But his interest grew stronger when Tsung-Dao Lee and Chen Ning Yang shared the Nobel Prize in Physics in 1957, becoming the first Chinese scientists to win the coveted award. “That stimulated a lot of Chinese students to pursue high-energy physics, including me,” Leung says. In rapid succession, he received an undergraduate degree from the Chinese University of Hong Kong, a master’s from the University of Akron, Ohio; and a doctorate from the University of California at Los Angeles.

It was at UCLA that his focus shifted from high-energy physics to plasma physics. He switched for two reasons. First, he worried that high-energy physics had already peaked as a science, and the remaining research jobs would become scarce. Secondly, the nation was gripped in an energy crisis, and the Department of Energy was funding research on alternative energies such as fusion energy, which involves plasma physics.

“There were long lines at gas stations, and we needed to find other forms of energy,” Leung says. So, he came to Berkeley Lab in 1978 to join the Magnetic Fusion Energy Group, which is tasked with developing fusion-energy options.

“I was responsible for the negative ion source development for future neutral beam injectors,” Leung says. He has since applied his expertise in ion beams to a wide range of seemingly unrelated applications, from cancer therapy to oil-well logging. And aside from a brief stint as a visiting professor at the Institute of Applied Physics at Germany’s University of Frankfurt, Berkeley Lab has remained his home.

“Our research evolves into different applications based on the nation’s needs,” Leung says.