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This issue...

   Brieflies

  View from the Inside

  Sandia Sells Seashells

  Asymmetric Dancing Partners

  Working Science

  People

  Site Seeing

  E-mail Reminder

View from the Inside

The Fusion Program has Changed Direction

Anne Davies, Director of the Office of Fusion Energy Sciences, Tells Us About It

by Nona Shepard


Photo of N. Anne Davies
N. Anne Davies
View: Dr. Davies, there have been some big changes in your fusion program over the past few years. What were those changes; and what do you see as the future for your program?

Davies: Until three years ago, our goal was a fusion demonstration plant in operation by 2025. We didn't have the funding required but we had the goal. Then, three years ago, Congress reduced our budget by a third-from about $368 million in FY 1995 to about $244 million in FY 1996, with a further reduction in 1997, and gave us very clear direction to stop trying to be a goal-oriented, milestone-driven program and to redirect and restructure the program to be science-based and much broader. Today, we have a new mission statement—to acquire the science and technology base for an economically and environmentally attractive fusion energy source. What we're doing for the foreseeable future is science: experiments, theory, enabling technologies in support of the science experiments, and research on some of the long-range technologies that you would need for energy applications.

View: Would you elaborate a little, please, on the new direction Congress gave you?

Davies: Well, in addition to reducing our budget by more than a third over the course of two years, it was clear that Congress wanted us to do something different. Our program had focused almost exclusively on the Tokamak concept for magnetic confinement. Congress told us to broaden the program, focus on science and near-term goals while doing the work on alternate concepts. These cuts and this refocusing were difficult. For example, from the human resource point-of-view, we lost some 800 people out of the program and we had to shut down some facilities, too. But we emerged from this transition with the current science-based program that has energy as its long-term goal.

View: The program had focused on the Tokamak concept. Has broadening the program affected that focus?

Davies: Magnetic confinement is still focused on toroidal magnetic configurations. Tokamak is a Russian word that means toroidal magnetic chamber, but the "Tokamak" means a specific thing; it looks pretty much like a donut as opposed to a bicycle tire or an apple. Now we have bicycle tires and apples in the program, too.

The fact is that our fusion community had been uncomfortable having focused so much effort on the Tokamak. The Tokamak that we had just three years ago has evolved into a better Tokamak concept—called an Advanced Tokamak to distinguish it. And the program now includes a number of other toroidal concepts that are, more or less, related to the Tokamak, but different. They each have advantages over the Tokamak, but also possible disadvantages and uncertainties because we don't know them as well as the Tokamak yet. But we are carrying out research on a broad front, and we find many synergisms among these related toroidal configurations. Our expectation is that this broadening will result in an optimum toroidal magnetic confinement and lead to a better energy system and a much smaller power plant.

View: For electrical power generation?

Davies: Yes, for power generation or any of the other possible applications of fusion: for producing isotopes, for transmutation of waste, or for process heat. There are a number of applications that have lower requirements than central station electricity production. But our focus has been on electricity.

View: Fusion actually takes place in the plasma that is contained within the toroidal machine. Would you describe, or explain, plasma for us?

Davies: Plasma is not so common on the earth, but very pervasive in outer space. It permeates interstellar space; and stars like our sun are balls of plasma.

Plasma is called the fourth state of matter: if you heat a solid, it becomes a liquid; if you heat a liquid, it becomes a gas; if you heat a gas enough, it becomes a plasma. Plasma is a substance that fills its container. It doesn't have to be very dense, but it has to be hot enough that the atoms break down and the electrons are separated from the nucleus. So, it is a soup of charged particles. The electrons have a negative charge and the nucleus has a positive charge; and the electrons and the nuclei are always recombining in this plasma. When they do, light is emitted. A fluorescent light is a mercury vapor plasma. A neon light is a neon-vapor plasma. It's a low-density gas that has a current running through it. There is no wire down the middle of that bulb, only a plasma produced by a voltage across the ends.

View: I've heard that interesting new things have been learned about plasmas.

Davies: Well, we certainly have learned many new things about Tokamak plasmas, which are relatively high-temperature and relatively high-density plasmas. But what's most exciting is what came out of the review three years ago—that this Office should become the steward of plasma science. We're not the only ones in the government who fund plasma research—the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the Department of Defense (DoD) do also—but, through fusion research, we've been by far the largest funder of plasma science and we've trained most of the plasma scientists who work in the field. What we've not done in the past is fund general plasma science. We've begun to do that whether or not the research has any direct, near-term relevance to fusion science.

One of the first things we did was join with the NSF in a joint program to fund general plasma science: plasma physics; plasma chemistry; and plasma engineering, including experiments, theory, and modeling. We did a joint solicitation and funded 37 university grants. We are funding more of them this year. The Department itself instituted a "junior faculty award" in plasma science research for tenure track faculty at universities, particularly at universities not already involved in fusion research. So this was a double effort to bring both additional institutions and young faculty members into the program for a few years until they can establish themselves and apply for standard grants. We've got really excellent young researchers now under grants from this Office.

Plasma science, especially low-temperature plasma science, may not be particularly relevant to the fusion research program right now. But our belief, our philosophy, is that through funding plasma science, because it is the foundation science for fusion, the fusion program will benefit in the long term. And because plasma science can lead you to better coatings and better materials that can make better furnaces and better engines, this research can contribute to DOE's other energy missions. For example, the pistons in the Saturn [automobile] engines are hardened by a plasma implantation process.

View: What's the biggest scientific issue in fusion energy?

Davies: The next scientific issue is what happens when you have a self-sustaining plasma; a plasma hot enough, dense enough, and confined enough to keep the reactions going so that you can light it and take away the match and it will keep burning. That is a major experiment and costly. We've recognized for some time that the only way the U.S. would be able to do this would be through international collaboration, and we've been participating in the International Thermonuclear Experimental Reactor (ITER) project with the European Union, Japan and the Russian Federation. Last year, however, Congress told us to resign from ITER and so we are spending this year withdrawing. We've brought our people back from the design team, we've closed the design center that we hosted in San Diego, we've sent our partners' scientists who were in the U.S. to the other design centers, one in Japan and one in Germany, and we're finishing the R&D on components this fiscal year. I'm hoping our partners will be able to go forward without us, because if they're able to build ITER, it will be a remarkable achievement for fusion.

View: Why do you think Congress was so tough in making the U.S. withdraw from ITER?

Davies: The goal of ITER is to demonstrate the scientific and technological feasibility of fusion energy. The combination means ITER will have to be large-scale and costly. Our partners in ITER declared that they didn't want to do only the science, at the lowest possible cost, because that is a technology that doesn't extrapolate to a power plant. Congress felt that the U.S., because of budget constraints, couldn't be a full partner in this effort and feared that the other partners might not ultimately go forward with it. So, we're going to focus on what we need to do domestically. Our research will be very open and we will willingly share the results with our ITER partners. If our partners go forward with ITER, we would consider whether to propose participating in some way by bringing something to the science part of the program.

View: What else is going on within the Office of Fusion Energy Sciences?

Davies: Well, I've been talking only about the magnetic fusion program. We've got a small, but high-leverage part of a program that's called Inertial Fusion Energy (IFE)—to distinguish it from the Defense Programs' Inertial Confinement Fusion (ICF) program.

In inertial fusion, a tiny pellet is compressed and heated very quickly by beams of particles or light. The defense people study the target physics. They're imploding pellets and measuring what happens, but they don't care how efficient the driver is. They might only pulse it a couple of times a day. If you want to turn that physics into an energy system, it has to have a really efficient driver at about 5 pulses per second. If we're going to put this on someone's electricity grid , it's our job to develop the components that you would need to turn this physics into an energy system with efficient drivers that can operate repetitively. We've been funding, at a very modest level, heavy ion accelerator research because that has been considered the most likely candidate for the energy driver. But we're also funding some smaller efforts on target chambers; for example, how to get all the debris cleaned out in time to make another pulse a fraction of a second later.

View: Accomplishing fusion energy has already taken decades. Are you discouraged?

Davies: I'm not discouraged at all because the science has been coming along very well. I think people who are involved in it and know it are more confident today that fusion can be used as an energy source than they were 10 years ago. The questions are more: Will it be economical? Will it be environmentally acceptable since it is still a nuclear process? It's orders of magnitude safer than fission when you consider the volatility and the biological hazards of the materials in the plant. But is it safe enough? Will the public accept it? I'm optimistic that the public will because the climate change issues are going to continue to be with us. There are issues associated with every energy source and I really believe that the country and the world needs a portfolio of energy sources and that fusion can and should play an important role. Three years ago, the President's Committee of Advisors on Science and Technology concluded that, too. When people take the time to review the fusion program, its goals and its accomplishments, they see its value and conclude that fusion should be an element in the country's energy R&D portfolio.

View: And that's a positive note on which to end. Thank you, Dr. Davies, for sharing your insights with us.


N. Anne Davies, Ph.D., joined the Atomic Energy Commission in 1974 as a physicist in the fusion program office. Since that time, she has held various positions within what is now the Department of Energy's Office of Fusion Energy Sciences. Davies has served as the Director of the Office since 1989. She is a member of the American Physical Society and has received DOE's Meritorious Services Award (1984), the Meritorious Executive Presidential Rank Award (1991), and the Secretary's Award (1997).

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