In a scientific complex on 88 bucolic acres near here, some astonishingly talented people are advancing a decades-long project to create a sun on Earth. When â?? not if; when â?? decades hence they and collaborators around the world succeed, their achievement will be more transformative of human life than any prior scientific achievement.
TheÂ Princeton Plasma Physics Laboratoryâ??s (PPPL) focus â?? magnetic fusion research â?? began at the university inÂ 1951. It was grounded in the earlier work of a European scientist then living in Princeton.Â Einsteinâ??s theoryÂ that mass could be converted into energy had been demonstrated six years earlier nearÂ Alamogordo, N.M., by fission â?? the splitting of atoms, which released the energy that held the atoms together. By the 1950s, however, attention was turning to an unimaginably more promising method of releasing energy from transforming matter â?? the way the sun does, by fusion.
Every secondÂ the sun produces a million times more energy than the world consumes in a year. But to â??take a sun and put it in a boxâ?ť â?? the description of one scientist here â?? requires developing the new field of plasma physics and solving the most difficult engineering problems in the history of science. The objective is to create conditions for the controlled release of huge amounts of energy from the fusion of two hydrogen isotopes,Â deuteriumÂ andÂ tritium. Hydrogen is the most abundant element in the universe; Earthâ??s water contains a virtually inexhaustible supply (10 million million tons) of deuterium, and tritium is â??bredâ?ť in the fusion plant itself.
TheÂ sunÂ is a huge sphere of plasma, which is a hot, electrically charged gas. The production and confinement of plasma in laboratories is now routine. The task now is to solve the problem of â??net energyâ?ť â?? producing more electrical power than is required for the production of it.
Magnets produce a field sufficient to prevent particles heated beyond the sunâ??s temperature â?? more thanÂ 100 million degrees CelsiusÂ â?? from hitting the walls of the containment vessel. Understanding plasmaâ??s behavior requires the assistance ofÂ Titan, one of the worldâ??s fastest computers, which is located atÂ Oak Ridge National LaboratoryÂ in Tennessee and can performÂ more than 17 quadrillionÂ â?? a million billion â?? calculations a second.
As in todayâ??sÂ coal-fired power plants, the ultimate object is heat â?? toÂ turn water into steamthat drives generators. Fusion, however, produces no greenhouse gases, no long-lived nuclear waste and no risk of the sort of runaway reaction that occurred atÂ Fukushima. Fusion research here and elsewhere is supported by nations with half the worldâ??s population â?? China, India, Japan, Russia, South Korea and the European Union. The current domestic spending pace would costÂ $2.5â??billion over 10 yearsÂ â??Â about one-thirtiethÂ of what may be squandered inÂ California on a 19th-century technologyÂ (a train).Â By one estimate, to bring about a working fusion reactor inÂ 20 years would cost $30â??billionÂ â?? approximately the cost of one week of U.S. energy consumption.
Given the societal will, commercially feasible production of fusion energy is possible in the lifetime of most people now living. TheÂ cost of operating the PPPL complex, which a century from now might be designated a historic site, isÂ 0.01â??percent of U.S. energy spending. PPPLâ??s budget is a minuscule fraction of U.S. energy infrastructure investment (power plants, pipelines). Yet the laboratory, which once had a staff of 1,400, today has only 450.
TheÂ Apollo space programÂ was much less technologically demanding and much more accessible to public understanding. It occurred in the context of U.S.-Soviet competition; it was directly relevant to national security (ballistic missiles; the coin of international prestige); it had a time frame for success â?? President Kennedyâ??s pledge to go to the moon in the 1960s â?? that could hold the publicâ??s attention and incremental progress (orbital flights) the public could comprehend.
Because the fusion energy program lacks such immediacy, transparency and glamour, it poses a much more difficult test for the political process. Because of its large scale and long time horizon, the fusion project is a perfect example of a public good the private sector cannot pursue and the public sector should not slight. Most government revenues now feed the publicâ??s unslakable appetite for transfer payments. The challenge for todayâ??s political class is to moderate its subservience to this appetite sufficiently to enable the basic science that will earn tomorrowâ??s gratitude.