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 — not if; when — decades hence they and collaborators around the world succeed, their achievement will be more transformative of human life than any prior scientific achievement.
The Princeton Plasma Physics Laboratory’s (PPPL) focus — magnetic fusion research — began at the university in 1951. It was grounded in the earlier work of a European scientist then living in Princeton.
Albert Einstein’s theory that mass could be converted into energy had been demonstrated six years earlier near Alamogordo, N.M., by fission — 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: the way the sun does, by fusion.
Every second the sun produces a million times more energy than the world consumes in a year. But to “take a sun and put it in a box” — the description of one scientist here — 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, deuterium and tritium. Hydrogen is the most abundant element in the universe; Earth’s water contains a virtually inexhaustible supply (10 million million tons) of deuterium, and tritium is “bred” in the fusion plant itself.
The sun 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 “net energy” — producing more electrical power than is required for the production of it.
Magnets produce a magnetic field sufficient to prevent particles heated beyond the sun’s temperature, more than 100 million degrees Celsius, from hitting the walls of the containment vessel. Understanding plasma’s behavior requires the assistance of Titan, one of the world’s fastest computers, which is located at Oak Ridge National Laboratory in Tennessee and can perform more than 17 quadrillion — a million billion — calculations a second.
As in today’s coal-fired power plants, the ultimate object is heat to turn water into steam that drives generators. Fusion, however, produces no greenhouse gases, no long-lived nuclear waste and no risk of the sort of runaway reaction that occurred at Fukushima.
The current domestic spending pace would cost $2.5 billion over 10 years. By one estimate, to bring about a working fusion reactor in 20 years would cost $30 billion, 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 lifetimes of most people now living. The cost of operating the PPPL complex, which a century from now might be designated a historic site, is 0.01 percent of U.S. energy spending. PPPL’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.
The Apollo space program 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 — President John F. Kennedy’s pledge to go to the moon in the 1960s — that could hold the public’s attention, and it offered 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 public’s unslakable appetite for transfer payments. The challenge for today’s political class is to moderate its subservience to this appetite sufficiently to enable the basic science that will earn tomorrow’s gratitude.
