Despite International Agreement On Fusion, Future Of Research In U.S. Remains Murky

U.S. Remains Murky Date: December 7, 1992 It's the worst of times, but in some ways it's also the best of times for fusion researchers. On the upside is a complex, four- party agreement that was signed in July, commiting the world fusion community to a collaborative effort to design the next- generation fusion experiment. The United States is joining Japan, Europe, and Russia to design the International Thermonuclear Experimental Reactor (ITER). The bad news is that the agreement is only to design the plant, not to actually build it. And, aside from this project, physicists complain that there really are no other major new experiments planned for U.S. researchers. Budget constraints have forced the domestic fusion effort to survive on experimental facilities built in earlier years and to put all its eggs into one basket, the tokamak design--a doughnut-shaped device that confines the fusion plasma via a magnetic field. This tokamak focus has led to the exclusion of many other alternative approaches. Institutions such as Los Alamos National Laboratory and Lawrence Livermore National Laboratory have experienced serious downsizing of their fusion work forces as a result of the budget squeeze. And many physicists fear that the overemphasis on the tokamak is committing the fusion program to a design that will be too large and too complex to ever be commercially successful. "The fusion budget has been flat for a long time and, in fact, it's been eaten into badly by inflation," says physicist Robert Park, spokesman for the American Physical Society. "And there's real suffering in that research community right now as a result." "What we're doing in the fusion program right now is living on past investments made in the 1970s," says plasma physicist Ian Hutchinson, head of the torroidal confinement division of the Plasma Fusion Center at the Massachusetts Institute of Technology. "Unless we get on with building new experiments, it's going to be a bleak season for fusion research in the U.S." Hutchinson says the glory days for fusion research came just after the Arab oil embargo of 1973, when alternatives to fossil fuels were pressed to the research forefront. But now the urgency has faded and the fusion budget, in real dollar terms, has been cut in half, according to U.S. Department of Energy (DOE) officials. The MIT center, which receives about $32 million of the $336 million federal fusion budget, has about 250 people working mainly on plasmas and on fusion, says Hutchinson. Their biggest experiment is called Alcator C-MOD, which has been in design and building phase since 1987 and is still being fine-tuned. Alcator C-MOD, a small, flexible experimental device, is "one of the few experiments built in the U.S. in the past 10 years," he says. Continuing to ride the downward spiral in research funding would be devastating, according to a September 1992 report from DOE's Fusion Energy Advisory Committee. "Under this budget scenario it is highly unlikely that the U.S. could be an effective participant in ITER construction and operation," according to the report. "Also, with the shutdown of TFTR [Tokamak Fusion Test Reactor] in FY 1994 and in the absence of resources to begin a major post-TFTR initiative as a national facility at the Princeton Plasma Physics Laboratory [PPPL], the U.S. position as a world leader in experimental confinement physics and the role of PPPL as a key national resource for fusion work in the U.S. will be seriously eroded. The loss of critical personnel with fusion expertise nationwide will be severe." Hope And Anxiety Hutchinson says there are some hopeful signs from Washington, D.C., that fusion's declining fortunes may soon be reversed. Fusion energy was included as part of the mix of resources called for in the National Energy Strategy, a comprehensive DOE plan published in 1991 that "lays the foundation for a more efficient, less vulnerable, and environmentally sustainable energy future." According to the strategy: "Fusion energy offers the potential to provide an inexhaustible supply of electricity with little, if any, environmental impacts." Hutchinson says that talk of a fusion budget hike began after a DOE-appointed task force reported in September 1991 that "funding for the magnetic fusion program must increase at a modest rate (e.g., 5 percent real growth per year) even at the expense of other programs." But this discussion was initiated during the Bush administration, and, he says, "I have no idea what view the new administration will take of fusion." Some insight into the new administration's viewpoint might be gleaned from Vice President-elect Al Gore, who on page 328 of his book Earth in the Balance (New York, Houghton Mifflin, 1992) says: "Research and development should continue vigorously, especially in technologies like fusion power which offer the prospect, however distant, of somewhat safer and more abundant sources of electricity." While such words may be reassuring to many in the fusion community, the wording of this year's Senate appropriations committee report was not. It allocated $336 million in fiscal year 1993 for fusion--about $1 million below FY 1992 and $23 million less than the administration request--and the committee warned an already lean research community to prepare for more belt tightening. "Given the present budgetary constraints, [DOE] is directed to prioritize the remaining magnetic fusion programs, identifying their contribution to ITER, tokamak improvements, and fusion technology. The Department is also directed to provide the Committee with a plan for consolidating its fusion efforts into fewer, more effectively utilized facilities by February 1, 1993," the report states. Congress did, however, give generously--$60 million--to ITER, with these funds to go out to U.S. industry, national labs, and university teams to support the engineering design activity for this multinational collaborative effort. For instance, DOE has already awarded Pittsburgh-based Rockwell International Corp. a $4 million, six-year contract to design a remote handling system for the ITER reactor. Other contracts to develop superconducting magnets have been granted to General Dynamics Corp. of St. Louis, and to Westinghouse Electric Corp., headquartered in Pittsburgh. Mirroring the U.S. fusion effort, the ITER will be working toward a tokamak design, originally developed in the early 1950s by Russian physicist and activist Andrei D. Sakharov as well as Igor Y. Tamm. In the tokamak, plasma is injected into the reactor vessel, and because that plasma is composed of positive and negative ions, it is confined by powerful magnets wrapped around the outside. Another set of magnets induces a current in the plasma that imparts 1,000 electron volts of energy. To boost this plasma to the point at which deuterium and tritium will fuse requires injecting additional high-energy plasma components or supplying radio-frequency heating. Fusion of deuterium was achieved long ago, but even the best tokamak experiments have failed to reach break-even--the state at which energy supplied to the plasma equals the amount it produces in terms of energy, such as neutrons. The ITER is expected to go beyond break-even to produce a "burning plasma," for which no external energy will be required to further fuel the fusion reaction. And beyond the ITER would be the first demonstration reactor, possibly as early as 2025, at least according to the National Energy Strategy. But many physicists feel that keeping the ITER program on track will be a challenge, given that there are separate design centers in the U.S., Japan, and Europe. "We were very skeptical about whether you could make this work with three different geographic locations," says Anne Davies, director of DOE's office of fusion research. "But people think that this will work." While there may be logistical difficulties in having a mixed team of workers from each of the participating nations at each design center, it is a necessity of international politics. "Everyone wants to know how to design a whole reactor when this is done," Davies says. And given the high cost of going it alone on the $8 billion superconducting supercollider, Congress is not in the mood for any more high-priced physics projects. "So, I think we've garnered a lot of support [in Congress] by virtue of the internationalization of the project," she says. Meanwhile, what Davies terms America's "premier physics experiment," the Princeton University Plasma Physics Laboratory (PPPL) tokamak, is entering what researchers there are calling its "golden era." The excitement is that after years of fine- tuning a deuterium-deuterium fusion system, PPPL is poised to enter the next, more energetic phase--fusing deuterium with tritium, which will yield about 10 megawatts of power for every 30 MW put in. These are exciting times for PPPL, but the question many researchers there are asking is what comes next. With no funding for a big next step and with ITER just entering a six-year design phase, PPPL plasma physicist David Johnston says, "there's going to be a gap in the U.S. fusion program." Fellow PPPL physicist Mike Zarnstorff says, "it's pretty discouraging that all the major experiments in the U.S. are at or near the end of their lives." As is typical of fusion researchers, Zarnstorff's attraction to the field was not simply to do challenging physics but to work on a project with practical consequences. And his commitment is still strong despite "a fair degree of skepticism" that adequate funding for fusion will continue and that the ITER effort will ultimately gel into a reactor design that will be built. The fact that he and other principal researchers are still at PPPL indicates "we're going to persevere," Zarnstorff says. And, as Johnston adds, "We probably feel we all have a few years yet here at PPPL." However, if fusion continues its slide, Zarnstorff does not see his research career as over. "If fusion dried up and blew away, there's a good chance I'd go into computer science," he says. Others are not necessarily waiting until the final moment and have left PPPL for either academic posts or, in rare cases, appointments at foreign labs. "We've lost a number of people and we've not been able to fill their slots with anyone new. And that will continue," Zarnstorff says. PPPL director Ron Davidson is a fusion optimist, who believes that there are technological challenges, but no "insurmountable technical impediments," to developing a fusion energy reactor in the next century. And, he says, the subject still has "a great appeal" to graduate students, with six or seven admitted to Princeton each year. DOE's Davies agrees that the field is not being abandoned at the graduate level. "People tell me in the universities that they are still getting very excellent graduate students with an interest in fusion. This is gratifying to me because I've been worried people would desert the field," she says. Davidson says that while not all these grad students will go on with fusion research, they still get a valuable education in the burgeoning discipline of plasma physics. "Plasma's a rather pervasive state of matter, so it's hard to avoid," says Davidson. Some graduates will go on to study plasmas in the astrophysical realm, while others will develop industrial applications of hot, ionized gases, such as etching of semiconductor wafers, he says. Although tokamak research is currently ascendant, many physicists warn that if scaled up to commercial reactor size, tokamaks will be extremely expensive, enormous devices that no utility will want to build. So, another promising approach, called inertial confinement fusion (ICF), is under development both in the U.S. and abroad. In the ICF process, small fuel pellets are bombarded by high-intensity laser or particle beams to produce a small quantity of plasma. Whereas tokamaks require both the driver (the magnets) and the reaction chamber to be built as a single unit, with ICF the bombarding driver can be separated, making the reactor simpler. ICF could be a cheaper, smaller, faster-to-develop method of getting energy from fusion, according to some physicists. "There's no question in my mind that ICF may beat magnetic fusion to producing the first commercial reactor," says Gerald Kulcinski, director of the Fusion Technology Institute at the University of Wisconsin, Madison. DOE's Davies says, "I don't think ICF would be cheaper, but it could be faster to develop, if we chose the right driver." A modest sum, $9 million per year, is being devoted to developing a heavy-ion beam driver. If that driver succeeds in igniting a gas-filled pellet, ICF could make big inroads into the tokamak's leading role in the fusion research effort, says Kulcinski. As Kulcinski and colleagues wrote in the September issue of Physics Today (W.J. Hogan, et al., 45:43): "Inertial fusion energy's potential for low-cost development makes it an attractive fusion option. The inertial fusion energy community is prepared to take the next steps--demonstrating ignition and gain, developing a reaction driver, and choosing a reactor technology-- when the country determines it can afford to do so." But Princeton's Zarnstorff believes it will take another energy crisis for the public to again decide fusion is affordable. "I think if people started freezing in the dark, the fusion issue will come back."

Despite International Agreement On Fusion, Future Of Research In U.S. Remains Murky

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