John A. Nation, professor emeritus of electrical and computer engineering, whose research on high-power microwave generation helped drive Cornell’s role in advancing plasma studies and fusion energy, died on Sept. 3 in Rye, New Hampshire. He was 89.

Nation joined the Cornell faculty in 1965 and served as associate director of the Laboratory for Plasma Studies before serving as director of the School of Electrical and Computer Engineering from 1984 to 1989.

Nation was the first to apply pulsed, relativistic electron-beam technology to the generation of intense microwave signals, which were capable of providing power in magnitudes not available from other sources. Over the years, Nation designed and built several pulsed-power machines and diagnostics that contributed to the evolution of plasma studies at Cornell and elsewhere. He and other researchers saw applications in controlled thermonuclear fusion – a research emphasis brought by the U.S. energy crisis of the early 1970s.

A fellow of the Institute of Electrical and Electronics Engineers and the American Physical Society, Nation was awarded the IEEE Centennial Medal in 1983 for his outstanding contributions to electrical engineering.

Aside from his research, Nation developed and taught courses in electromagnetic fields and waves, and he was the first instructor at Cornell to introduce the use of computers in those courses.

Nation’s research record attracted talented graduate students from a wide range of backgrounds – students who benefited from his expertise in experimental plasma physics and the opportunities he provided to broaden their knowledge and technical skills, said Graham Kerslick, professor emeritus and former executive director of the Cornell Atkinson Center for Sustainability.

“John also ensured that the group’s technical staff were included at every stage of research planning. The students were encouraged to work with staff members to learn fabrication techniques and develop the skills that would serve them well in their future careers,” said Kerslick, who was a postdoctoral researcher under Nation before joining him in the Laboratory for Plasma Studies from 1983 to 1997. “In talking with John’s students over the years it was clear to me that they really appreciated John’s open and approachable manner in mentorship.”

Born in England, Nation received his B.S. in physics from Imperial College, London, in 1957, followed by a Ph.D. in 1960. His early career included work at the Comitato Nazionale per l’Energia Nucleare Laboratory in Frascati, Italy, and the Central Electricity Generating Board’s research laboratories in England. He was a consultant to several industrial and government research laboratories and served as a reviewer for various professional journals.

After retiring in 2000, Nation moved to Arizona with his wife, Sally. Following her death in 2022, Nation relocated to New Hampshire to be closer to his family. He is survived by his sons Robert and Philip.

Syl Kacapyr is associate director of marketing and communications for Cornell Engineering.