Physicist honored with new APS award
It’s fitting that Theory Department physicist Ilya Dodin was the first to receive the American Physical Society’s Thomas H. Stix Award for Outstanding Early Career Contributions to Plasma Physics Research.
Dodin, honored at the annual APS-Division of Plasma Physics meeting in New Orleans in October, was recognized for his research on waves in plasmas. The award is named for the late Princeton University Physics Professor Thomas H. Stix, a pioneering plasma physicist at PPPL and director of the Princeton graduate program in Plasma Physics. Stix, who died in 2001, wrote one of the most influential books about waves in plasmas.
There are numerous different types of waves in plasma, an electrically charged gas. Dodin’s work devising mathematical formulas that can accurately describe how they operate may provide the key to learning how to control them.
Dodin, who splits his time between the University and PPPL, uses Stix’s textbook “The Theory of Plasma Waves” as a resource in a graduate course he teaches. Stix also taught the course, “Plasma Waves and Instabilities,” for many years. The course is compulsory for all graduate students in plasma physics, including Dodin, who took the course himself in 2000.
“I appreciate Ilya being the first recipient of the Thomas Stix award,” said Amitava Bhattacharjee, head of the Theory Department at PPPL. “It’s especially appropriate that he has won the prize in an area of work for which Professor Stix was celebrated.”
“I was really surprised and honored and I was very happy,” Dodin said after receiving the award during the conference. “I have recently been working with students a lot and this is very inspiring.”
From graduate student to “valued colleague
A native of the city Nizhniy Novgorod in Central Russia, Dodin graduated from the Advanced School of General and Applied Physics at Nizhniy Novgorod State University, where he received bachelor’s and master’s degrees. He arrived as a graduate student at PPPL and Princeton University’s Department of Astrophysical Sciences in 2000 and has never left. Dodin and his wife Eugenia Dodin, a pharmacist at University Hospital in Newark, live in Cranford, N.J.
Nat Fisch, director of the Program in Plasma Physics, was Dodin’s thesis advisor. Fisch said his former student is now a “valued colleague.” “He now teaches me more than I teach him. “Besides teaching me,” Fisch said, “Ilya Dodin has gotten glowing reviews from students taking his class precisely because he brings his own research into the classroom. He teaches students the mathematical formulas he has developed that describe plasma waves. I think students appreciate when you’re teaching a class and you bring a subject to life and point out not just what people know but how people use these tools in figuring out what they don’t know.”
Fisch said Dodin is not only “invaluable” to PPPL’s physics program and a brilliant researcher. “He also has a nice way about him in approaching problems in physics together with colleagues. He has a gentle way in dealing with people.”
There are a large variety of waves in plasma. The magnetic fields that confine the plasma in donut-shaped tokamaks, which are designed for controlled nuclear fusion experiments, allow the plasma to support an even greater variety of waves. Waves at radio frequency (RF waves) are injected into the plasma, heating it to 100 million degrees centigrade or more in order to create temperatures conducive to nuclear fusion. Still other waves can disrupt plasmas.
Formulas describe the behavior of waves
Dodin’s formulas describe the behavior of waves even as the parameters governing them change. “By putting equations in a simplified but robust form, you can see dynamics that are much harder to see from all-inclusive equations,” Dodin said.
“Some of the questions that drive Ilya Dodin are the subtle ones we’ve been asking ourselves,” Fisch said, “such as, ‘What is the momentum in a wave?’ ‘What happens to waves when a plasma is compressed?’,‘Can you construct a wall out of a wave in which some particles bounce off and some go through?’ and ‘Can you control waves with other waves?’”
Fisch has collaborated with Dodin over many years. “We had posted together a number of questions,” he said, “but the sophisticated methods to solve them are really Ilya Dodin’s own invention. It was Ilya’s own general approach that enabled us to reach solutions rigorously, and now Ilya has himself taken this approach much, much further than that.”
“The formulas he derived allow Ilya to look at waves “kind of like mathematical objects and that unique perspective allows him insights into the behavior of waves in general,” Fisch said.
Dodin’s formulas could apply to essentially all types of waves from light waves to sound waves. “The work that I’ve been doing is about learning how to make the approximations right for the general theory of these waves,” Dodin said. “We also apply it to specific waves too but the main point at this stage is to get the fundamental theory right.”
Dodin’s research could provide a more efficient way of analyzing waves found in fusion energy experiments like PPPL’s National Spherical Torus Experiment and ITER, the international fusion experiment in Cadarache, France. The formulas could eventually lead to codes that could be used in simulations aimed at controlling plasmas in fusion experiments. “If the code is more efficient you can experiment with it more and eventually you can predict the behavior of waves better. That can also lead to better ways of launching waves in a tokamak,” Dodin said.
Applications to other physics fields
The possibility of applying Dodin’s research to all kinds of waves has attracted the attention of researchers in other physics fields. For example, Dodin has been invited to talk to a group of atomic physicists. Because of his work on the very basic mathematical aspects of classical waves, he was also asked recently to write a chapter on waves in a book on the foundations of quantum mechanics. “I realized there are important connections with quantum mechanics,” Dodin said. “Quantum waves behave in a very similar manner to waves we have in plasma and there may be a lot of potential in bridging the quantum and plasma theories.”
Fisch predicts that Dodin’s formulas will have an even greater impact in the future as more physicists become aware of them and put them to use in their own research. “The greatest part of the impact is yet to come when people will begin to adopt these methods,” he said.
Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.
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