Newswise — Ronald C. Davidson, a pioneering plasma physicist for 50 years who directed the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) during a crucial period of its history and was a founding director of the Plasma Fusion Center at the Massachusetts Institute of Technology (MIT), passed away on May 19 at his home in Cranbury, New Jersey, from complications of pneumonia. He was 74.

“Ron was an anchor for the Laboratory both through his science and through his wisdom,” said Stewart Prager, director of PPPL. “His prodigious contributions not just to PPPL’s science but also to plasma physics writ large are clear and widely known. Within the Laboratory, he was a mentor and a guide to people young and old. His impact within the Laboratory was enormous.”

The physicist won numerous honors in his lifetime, including the prestigious James Clerk Maxwell Prize in Plasma Physics in 2008, the highest national honor in plasma physics. He was a fellow of both the American Physical Society and the American Association for the Advancement of Science.

Davidson was known as a prolific researcher, writer and academic who managed to keep many professional balls in the air at one time. He was editor of the Physics of Plasmas for 24 years from 1991 until last year. At the same time, he was a professor in Princeton University’s Department of Astrophysical Sciences until 2011. A prolific researcher up until his death, Davidson was the author of four graduate-level plasma physics textbooks and more than 500 articles.

Davidson was an expert in fields that include high-intensity charged particle beams, which studies the collective behavior of billions of charged particles that speed together through accelerators and can fly apart and burst against the accelerator's walls and ruin experiments. His contributions to understanding the behavior of these huge collections of particles, which are denser than those in today's accelerators, could be applied to inertial confinement fusion and could greatly increase the scientific contributions from future accelerators.

Director of PPPL from 1991 to 1996The director of PPPL from 1991 to 1996, Davidson “led the Laboratory through the tremendous accomplishments of the Tokamak Fusion Test Reactor,” Prager said. Davidson led PPPL when TFTR began using a mixture of half deuterium and half tritium for fuel in 1993. In November 1994, the TFTR achieved 10.7 million watts of fusion energy, a world record at the time and enough to power up to 3,000 homes. The machine was shut down in 1997 after Davidson stepped down as director. It set many world records.

Davidson was a native of Canada who grew up on a family dairy farm near Norwich, Ontario. He was driving a tractor by age 11, while attending elementary school in a one-room schoolhouse. He credited the hard work of farm life with teaching him the value of a strong work ethic, rising early, and getting work done on time.

He became interested in plasma physics while studying physics at McMaster University in Hamilton, Ontario. He had considered attending graduate school at the University of Illinois, but his fiancée, Jean, who was his high school sweetheart, wanted to go to the Princeton area. Davidson enrolled in the new Princeton Program in Plasma Physics, then directed by physicist Thomas Stix, and graduated in 1966 after just three years when he was 25.

Davidson worked at several institutions over the next decade or so. He did postdoctoral research at the University of California-Berkeley for two years. He went on to become a physics professor at the University of Maryland for a decade, with one year as a visiting researcher at Los Alamos National Laboratory. He spent two years as assistant director for Applied Plasma Physics in the Department of Energy in Washington, D.C., before going to M.I.T.

Director of MIT’s Plasma Fusion CenterAs director of MIT’s Plasma Fusion Center, Davidson was able to unify various departments into one central organization at a time when the Alcator C, an early version of today’s Alcator C-Mod tokamak, had just been completed.

“His biggest contribution was taking the plasma activities at MIT from a group of warring fiefdoms to a unified and productive laboratory,” said Ronald Parker, a professor of nuclear engineering and electrical engineering and computer science emeritus who succeeded Davidson as the director in 1988. “He basically put MIT’s Plasma Fusion Center on the map.”

“He established a whole new organization. I was very impressed with what he did,” said Miklos Porkolab, an MIT professor of physics and another former director of the Plasma Fusion Center at M.I.T. “What we have now is more or less following the way he set it up.”

After spending a decade as director at MIT and three more years on the faculty, Davidson became director of PPPL in 1991. He came to the Laboratory during a challenging time when the Lab was preparing the TFTR for experiments with deuterium and tritium, recalls Dale Meade, who was deputy director at that time. The experiment was a 24-hour-a-day, seven-day-a-week enterprise and broke new ground in fusion energy research, Meade said.

Davidson kept notes on all the experiments in small green spiral notebooks, Meade said. Every Sunday morning, he would call Meade and department heads for a full report. “He was just amazing in terms of how organized he was and how thorough in terms of analyzing the situation and developing plans to move forward,” Meade said. “What made it all even more pleasurable is he was so easy to work for and work with. He was extremely personable.”

Rich Hawryluk, the head of ITER and Tokamaks at PPPL, was head of TFTR when Davidson was director. He recalled Davidson was always a straight shooter. “You could go and talk to him and get a straight clear answer that lets you move forward,” he said.

PPPL physicist Rob Goldston, who succeeded Davidson as PPPL director, said he often went to Davidson for advice. “He just had a very clear moral compass,” Goldston said. “Many of us looked over his shoulder to see which was it was pointing. It was pretty clear to him what was right and wrong.”

Early textbook in the field Nat Fisch, director of the Princeton Program in Plasma Physics, recalls using Davidson’s 1972 book, “Methods in Nonlinear Plasma Theory,” in graduate school. “He believed in explaining himself and people grew up on his textbooks,” Fisch said. Davidson also wrote “Theory of Nonneutral Plasmas" (1974), "Physics of Nonneutral Plasmas" (1990), and, with PPPL physicist Hong Qin, “Physics of Intense Charged Particle Beams in High-Energy Accelerators” (2001).

A professor at Princeton University for 20 years, Davidson served as associate chair in the Department of Astrophysics. Adam Sefkow, a physicist at Sandia National Laboratory, one of many graduate students whom Davidson advised, recalled that Davidson was “an excellent mentor. He was very patient - a top-shelf scientist,” Sefkow said. “He led by example with his wisdom and judgment, his intelligence and productivity.”

Numerous research projects After stepping down as director of PPPL, Davidson continued his work editing the journal Physics of Plasmas and working on numerous research projects. He was deputy director of the U.S. Heavy Ion Fusion Science Virtual National Laboratory, a collaboration with the Lawrence Livermore and Lawrence Berkeley national laboratories. He also worked on the Paul Trap Simulator Experiment at PPPL, which simulated a particle accelerator. Both projects ended in 2012. “I felt like I couldn’t have been luckier to work under someone like Ron,” said PPPL physicist Erik Gilson. “The scientific direction, the way he led our programs, but also the mentoring, professional development, and guidance, was just invaluable.”

Davidson had a reputation for being a meticulous researcher and writer whose articles and equations needed little editing. “He was able to write just about flawlessly,” Hawryluk recalled. “The first thing he wrote down was just about ready to go to proof.” Davidson also amused colleagues by handing out holiday poems he had written at Christmas.

Qin, a physicist at PPPL and executive dean at the University of Science and Technology of China, received handwritten notes from Davidson on a paper the two were working on two days before he died. “Ron had a set of rules and standards to follow but he was not a perfectionist,” Qin said. “He was gentle and considerate to his collaborators.

“A story Ron told me is that his mother asked him to play piano when he was in that one-room country school,” Qin said. “He had to practice a few hours every day. Ron said he hated every minute of it and would rather use that time to derive equations, a habit that he kept all his life.”

Davidson served on nearly 30 review committees on fusion and plasma physics at institutions all over the United States and as far away as Japan and the former Soviet Union. He was chair of the American Physical Society’s Division of Plasma Physics and Division of Particle Beams and was co-chair of the National Research Council Review Committee on Inertial Fusion in 2010.

Davidson often talked about his early life as a farmer, but Fisch said his ability to chart a clear course as an administrator, a researcher, a professor, and a mentor, reminded him of a sailor. “He had a sailor’s instincts, just to pick the right direction, whether it was science or administration, in full view of the winds and currents of life. He had to guide the Laboratory and he just seemed to do it like a sailor.”

A lifetime doing what he lovedIn a 2014 interview, Davidson said he was optimistic about fusion energy becoming a reality, noting that “scientific progress in fusion has been enormous. What the field has accomplished with increasingly sophisticated diagnostic tools, major experimental facilities, and advanced numerical simulations is quite stunning,” he said.

In reflecting on his long career, Davidson said he had spent a lifetime doing what he loved. “When you talk about physicists working,” he said, “you should keep in mind that they are engaged in activities that they enjoy very much.”

Davidson is survived by Jean Davidson, his wife of 53 years; his daughter, Cynthia Premru, of Groton, Massachusetts; son, Ronald Crosby Davidson Jr., of Princeton; and four grandchildren, Will and Maddy Premru, and Crosby and Cayley Davidson.

A memorial service will be held on Thursday, May 26, at 1:30 p.m. at the Princeton United Methodist Church, 7 Vandeventer Ave., Princeton, New Jersey. In lieu of flowers, contributions may be made in Davidson’s memory to the "Prof. Ronald Davidson Memorial Scholarship Fund" at Princeton University. Contributions can be made online at makeagift.princeton.edu. Please note the fund's name in the comments box.

PPPL, on Princeton University's Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

*PPPL Science Editor John Greenwald contributed to this story.