ARPA-E, the U.S. government agency for funding innovative energy technologies, is preparing to launch a program to support alternative approaches to fusion energy that have the potential to steal a march on existing mainstream projects. The news will come as a relief to some fusion researchers at government labs, who had their funding cut completely in this fiscal year because of the ballooning cost of the U.S. contribution to the international ITER fusion reactor project in France. And it will offer an opportunity to a small number of privately funded fusion efforts that are proposing alternatives to traditional tokamaks and laser fusion approaches.
On 11 August, ARPA-E gave advanced warning of the new funding stream, called Accelerating Low-cost Plasma Heating and Assembly (ALPHA), so that researchers would have time to form into teams to bid for funding. The funding opportunity will be formally announced later this month or in September. Programs at ARPA-E, a part of the Department of Energy (DOE), typically have budgets of about $30 million and award 3-year grants of roughly $3 million each.
Creating a fusion reaction that can produce energy requires taking an ionized gas, or plasma, and heating it, compressing it, or both until it reaches hundreds of millions of degrees—much hotter than the core of the sun. Different types of reactors take different approaches: Tokamaks aim for low plasma densities but long confinement time; laser fusion opts for extremely high density but only for billionths of a second.
ALPHA will seek to explore the largely untested middle ground—moderate density for pulses measured in millionths or thousands of a second. It will also focus separately on “targets”—ways of getting the plasma into a stable, contained state—and “drivers”—the systems for delivering energy into the plasma to raise its temperature and density.
DOE previously funded such approaches through a program called High Energy Density Plasma (HEDP). It supported experiments in compressing plasma with electrical pulses, magnetic fields, lasers, and high explosives at national laboratories, including the Sandia and Los Alamos labs in New Mexico, and the Lawrence Livermore lab in California. But the ever increasing cost of building components for ITER has put a squeeze on such approaches as the DOE fusion budget has remained flat. HEDP was zeroed out of the budget altogether in the 2014 fiscal year, which began this past 1 October.
ARPA-E first expressed its interest in fusion in October 2013 when it organized a workshop on drivers for economical fusion technologies. ARPA-E staff visited many of the national labs to see HEDP projects. But insiders say that the program was held up because DOE’s Office of Fusion Energy Sciences objected to another DOE agency spending money on fusion when it was struggling to meet its commitments to ITER and other projects.
“I am delighted that ARPA-E has chosen to look for a fusion approach that might offer a lower cost development path than the traditional magnetic and inertial fusion approaches,” says Stephen Dean, director of the Gaithersburg, Maryland–based educational foundation Fusion Power Associates. “By choosing to focus on plasma fuel densities intermediate between the lower density tokamaks and the very high density laser approaches, they have laid claim to a regime that has been largely ignored by the large government-funded programs.”
*Update, 15 August, 11:08 a.m.: This article has been updated to include a statement from Fusion Power Associates' Stephen Dean.