Thinking Out Loud About Snowmass

Thinking Out Loud About Snowmass^1,2

Dr. Pete Politzer
General Atomics, San Diego, CA

politzer@fusion.gat.com

February 6, 2002

The question is "why bother with this Snowmass exercise?"

Three more specific questions which help in generating an answer to "why bother": What is the Snowmass meeting for? What do I (and my lab, OFES, the "cause of fusion", etc.) gain or lose by having this meeting and having me attend /participate? Why are the participants going through all of the preparatory exercises?

The following monologue is an attempt to find some answers to these questions.

Take a couple of steps backward. In the late 1970's the U.S. fusion program underwent an enormous expansion, largely in response to the oil shocks of that decade. Major new experimental facilities were built. The prospect of proceeding through the steps of D-T burning, engineering test reactors, and demonstration power plants was real. Success was expected to follow success.

The reality has been different.

The figure below gives the annual US fusion budget since the program's inception. The magnetic fusion program budget has been in decline for the past 25 years. Although the peak budget occurred in FY84 ($468M), in constant 2001 dollars the peak was in FY77 ($935M, adjusted). We are now at roughly a quarter of that number. Although OFES spending on fusion has been steady for the past five years, the trend has been step-wise downward; a stable period of 4-6 years followed by a drop.

plot of budget vs time

Several conclusions can be drawn from the budget numbers.

1) The idea of fusion does get strong and continuing support from the government. This research has been funded since 1951(!), for a cumulative total of $17.4B (in 2001$). And the support continues, even without much change in the standard "30 years from now" reply to the availability question. This is a credit to the fundamental promise of fusion energy. It is our biggest asset and should not be squandered.

2) Support for fusion R&D is steadily decreasing. In part this may be due a lack of motivation on the part of the government, perhaps because of cheap oil and gas. But there also has to be a decline in enthusiasm because of the failure to deliver a product in this period. Many knowledgeable people are expressing the opinion that fusion was a worthy goal, the U.S. gave it a generous try, but it just wasn't there.

3) No major new research facilities have been built since the early 1980's. The response to the budget cuts in the mid-80's, and again in the mid-90's, was to eliminate capital investment and to try to maintain staff levels as much as possible. This might have been a good short-term strategy, but now we have to deal with the long-term consequences.

4) Not only is the number of people involved in development of fusion declining, but those who remain are getting older. There was a big increase in research staff in the 1977-84 period, as major new facilities were built. This was the fusion "baby boom". Soon (within a decade), these people will begin to retire.

The inescapable conclusion is that, if fusion research and development in the U.S. continues in its present course, with the facilities we have now, in ten years or so the fusion program will quietly vanish.³

What will remain is a basic plasma physics research effort. It will likely be supported by some combination of DoE Basic Sciences, the NSF, and NASA. Without the fusion mission, the emphasis will be on magnetospheric, solar, and galactic plasmas— mostly theory and satellites. Low temperature plasmas, arcs-and-sparks, plasma processing, etc., have long since become completely separate fields. The equilibrium funding level is hard to estimate, but I'd guess that $50M/year would be generous. Without fusion, no one will be interested in things like tokamaks, RFPs, or any other laboratory plasma confinement device.

This is the gloomy condition the fusion program finds itself in. We can congratulate each other on major accomplishments, but from the outside the "so what" test is getting steadily more difficult to satisfy.

The only alternative scenario seems to be a "great leap forward".

This has to be an aggressive attempt to make a major step toward making fusion power a reality. It has to be something that will (a) convince our increasingly skeptical friends that fusion is still worth pursuing, (b) reverse the decline in the budget so that the prospect of implementing fusion power occurs within a finite time horizon, and (c) attract a new cadre of skilled and enthusiastic people to the field.

The only thing on the table at this point is a burning plasma experiment (a BPX).

This is what Snowmass is about.

By the way, the above three goals are consequences of making a great leap forward. Convincing the skeptics, increasing the budget, and attracting new people will come as a result of a burning plasma experiment—they can't be made preconditions. Some change will accompany the design and construction of this facility, but the big results will depend on major technical accomplishment. The risk is in taking the great leap, but the reward comes only when the leap is done.

The difference between now and all of the previous attempts at a "next step" is that the program is approaching the endgame I've described. Whether this is the last chance, or the next-to-last doesn't matter; it's clear that there are very few opportunities remaining.

So back to "why bother with Snowmass?"

First of all, it's a cumbersome, complicated, and infuriatingly slow process to turn the present trend in the fusion program around and to get the government (and the people it consults) to agree to support a burning plasma experiment. The Snowmass convocation seems to play a key role in this process. The senior advisory body devoted to fusion, FESAC, has officially recognized the obvious and announced that "it is now time to proceed" with a burning plasma. This an essential step: the fusion community recognizes that there is no scientific impediment to proceeding.
Next comes Snowmass, which is important because such a gathering will be understood as the rank-and-file of the fusion community blessing the notion of a burning plasma experiment. At this level, what happens at Snowmass doesn't matter (as long as there isn't a major revolt against the idea of a BPX). It is the fact that the fusion "community" appears to be getting its collective act together that's important.

There is one other feature of Snowmass that does relate to making a BPX happen. The stated purpose is to examine proposed facilities for a burning plasma experiment, and to assess their technical readiness to do the job. Regardless of the details of the outcome, the fact that this has been done will be seen as adding "we also know how to proceed" to the FESAC conclusions. It is at this point that many of those involved in specific facilities have concerns. Although it is not a formal goal of the Study, there is the strong possibility that one proposal will be seen as significantly "better" or "worse" than the others.

The next steps after Snowmass are to get a recommendation from another FESAC panel as to which BPX concept is favored [small (Ignitor), medium(FIRE), or large (ITER)], and to get an independent scientific review, by a panel of the National Academy of Sciences. Presumably after that, and taking into consideration the convoluted and mysterious process of the international ITER negotiations, an attempt will be made to bring the people who count into line (the Secretary of Energy, the President's Science Advisor, OMB, key Congressional people, etc.).

This seems to be where Snowmass fits into the grand scheme of things. So if it's crucial that the fusion program proceed with a burning plasma experiment, the body count at Snowmass is important.

There is bound to be an upheaval in the structure of the fusion program if a burning plasma experiment goes ahead. Money and people will be moved around, new programs will be started, old ones will be shut down. The dislocation will be painful for some, but the alternative for almost all people and institutions now involved in fusion is likely to be worse.

Finally, regarding the technical work being done to "prepare" for Snowmass. It would seem that the best reason for doing this is to enable the discussion at Snowmass to cut through the smokescreens of unsubstantiated claims and allow an informed discussion of the relative merits of small, medium, or large. Whether this actually happens can only be judged this summer in Colorado. Those who favor one of the approaches (or want to make a case for no burning plasma experiment) should go and argue their case.

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[1] The 2002 Fusion Summer Study at Snowmass, Colorado.

[2] This discussion is confined, more or less, to the issues of magnetic fusion. The IFE folk have their own problems to deal with.

[3] A hard-core techie with no sympathy for political issues would have no qualms about fitting a curve to the budget data and extrapolating. For these folks: fitting a straight line to the adjusted numbers since 1977 gives a zero budget in 2007. A fitted exponential has a time constant of 16 years and an asymptote of $13M. Make of this what you will.