NEW YORK — Ronald C. Davidson, who oversaw one of the biggest advances in fusion energy research, attempting to replicate the power of the sun, died May 19 at his home in Cranbury, N.J. He was 74.
The cause was complications from pneumonia, said the Princeton Plasma Physics Laboratory, where Dr. Davidson was director from 1991 to 1996. Before that, he was the director of the Plasma Fusion Center at the Massachusetts Institute of Technology.
Fusion is the process that powers the sun, generating energy through the merging of atoms, and, for decades, scientists have tried to reproduce that on Earth. During Dr. Davidson’s tenure, the Princeton lab made major advances toward that goal, studying ways to make the fusion self-sustaining.
In 1993, the laboratory’s immense Tokamak Fusion Test Reactor began a series of runs using a mix of deuterium and tritium, two heavier forms of hydrogen. (“Tokamak” is an acronym of three Russian words that mean “toroidal magnetic chamber,” referring to the doughnut-shaped reactor that housed the ultrahot gases.)
In November 1994, the reactor generated 10.7 million watts of fusion energy, a world record at the time and enough to power 3,000 homes, if only for an instant.
“Very exciting times,” said Robert J. Goldston, a laboratory scientist who succeeded Dr. Davidson as director in 1996. “He guided that with a very steady and calm hand in what were fairly trying circumstances.”
With that much energy, “You had to do this very, very safely,” Goldston said. “We never had a problem with safety, but we had problems that made you think we better be careful.’’
The experiments laid the groundwork for future advances, including Iter, a much larger reactor under construction in France. The Princeton Tokamak reactor was shut down in 1997.
Born on July 3, 1941, in Norwich, Ontario, Ronald Crosby Davidson grew up on a dairy farm, learning to drive a tractor by 11. After graduating in 1963 with an undergraduate physics degree from McMaster University in Hamilton, Ontario, he enrolled in the plasma physics program at Princeton. He completed his doctorate in three years.
After a postdoctoral fellowship at the University of California Berkeley, he became a professor at the University of Maryland. He then moved to the Massachusetts Institute of Technology, where he was the founding director of the plasma fusion center.
“His biggest contribution was taking the plasma activities at MIT from a group of warring fiefdoms to a unified and productive laboratory,” Ronald Parker, who succeeded Dr. Davidson as the director, said in a Princeton statement.
In 1991, he was enticed to move back to Princeton, where Harold P. Furth had spearheaded the efforts to build the Tokamak Fusion Test Reactor. Furth stepped down in 1990 as director of the laboratory because of health problems.
After Dr. Davidson left as director, he returned to research, continuing as a professor in Princeton’s astrophysics department until 2011.
He was an author on more than 500 scientific papers and four textbooks. He also edited the journal Physics of Plasmas.
Dr. Davidson leaves his wife of 53 years, Jean; a daughter, Cynthia Premru, of Groton, Mass.; a son, Ronald Jr., of Princeton Junction; and four grandchildren.
A memorial service will be held at 1:30 p.m. Thursday, at the Princeton United Methodist Church.
Dale Meade, deputy director under Dr. Davidson, recalled phone calls with him every Sunday promptly at 9 a.m. to discuss the tasks for the week.
“He was highly organized and structured,” Meade said, recalling separate small green notebooks — one for his tasks as journal editor, one for what he needed to do as director, one for his personal research.
“He had lots of persistence,” Meade said. “Maybe that’s how he was able to inspire people without having to raise his voice.’’