Sir Steven Cowley *85 became the director of the Princeton Plasma Physics Laboratory in 2018. His world-class physics expertise and demonstrated ability to lead large scientific projects make him the ideal director for the lab at this time. I have invited him to share his goals for the future of PPPL.—C.L.E.

Steven Cowley *85, director of the Princeton Plasma Physics Laboratory
Courtesy of the Royal Society

Ninety-nine years ago, in a public lecture, astrophysicist Sir Arthur Stanley Eddington concluded that the prevailing theories of the sun were wrong. Assembling the earliest evidence for our modern understanding, he surmised that the sun must be powered by converting hydrogen into helium. Today we call it fusion power. Eddington mused about fusion’s potential, saying: “…we sometimes dream that [humanity] will one day learn how to release it and use it for [their] service. The store is well-nigh inexhaustible, if only it could be tapped.”

Eddington was right on all counts. Fusion—the process powering the sun and stars—is the perfect way to deliver the carbon-neutral, safe, and abundant source of energy that the world needs. Millions of years of fuel is available in sea water and fusion will have minimal environmental impact. There’s only one problem: we have not yet fully mastered the technology.

In 1951, Lyman Spitzer, then director of the Princeton Observatory, was among the first to take up the challenge of making a controlled fusion reactor on Earth. Since that time, the Princeton Plasma Physics Laboratory (PPPL) has been at the forefront of fusion research. Much of the field of plasma science, the physics of hot ionized gasses, was invented here. Many of the pioneers worked at PPPL and our graduate students have gone on to become scientific leaders in the field. Over the years, key advances in fusion research took place at PPPL. Indeed, our Tokamak Fusion Test Reactor was the first experiment to generate significant fusion power—10 megawatts.

I returned to Princeton 15 months ago to become the seventh director of PPPL with two overriding goals. First, we aim to drive the science and technology innovations necessary for commercial fusion power—in a sense, to complete the job Spitzer started. While we know how to do fusion, we cannot yet make electricity from fusion at a reasonable cost. However, promising new research is underway. For example, the U.S. Department of Energy (DOE) recently approved the rebuilding of our flagship experiment, the National Spherical Torus Experiment- Upgrade (or NSTX-U, for short), to investigate smaller and less expensive reactor concepts. The recent flood of venture capital into fusion research is also helping fund new ideas and launch new initiatives at PPPL. To test these innovations at scale, the U.S. will need a major new fusion research facility before the end of the 2020s. The obvious place for such a facility is PPPL. We are working hard to ensure it comes here.

My second goal is to diversify PPPL’s research by leveraging the connection to Princeton University. We want to make PPPL a truly multi-purpose National Laboratory. The DOE and the University trustees have endorsed this goal and it has been incorporated into the June 2019 update to the University’s strategic framework. Several specific initiatives are already underway.

The laboratory, with help from campus faculty, has begun a large collaboration with the microelectronics industry to develop the science of the next generation of plasma-fabricated computer chips. Our expertise in plasma science, largely developed in fusion research, makes us uniquely qualified to advance the field. PPPL’s plasma and engineering expertise will enable Princeton faculty in related areas to take their research to a larger scale—a scale that requires the engineering and project management that the laboratory can provide.

Since plasmas are so common around the universe—from the vast plasmas in galaxy clusters to the highly energetic plasmas swirling around black holes—it is not surprising that an astrophysicist founded PPPL. Over the past decade, PPPL has strengthened its connection to the Department of Astrophysical Sciences to address some of the most compelling problems in the universe. For example, the explosive release of magnetic energy (such as solar flares) in astrophysical plasmas will be studied in the Facility for Laboratory Reconnection Experiments, which has been transferred from campus to PPPL and will become a national user facility.

To advance our vision, new laboratories and collaborative computing spaces are needed. The DOE and the University are supporting the modernization of the laboratory infrastructure, and the DOE has approved the mission need for a new research building. The next few years will challenge the laboratory’s expansion capacities—but it is a challenge we welcome.

I first came to Princeton (and to PPPL) as a graduate student in the summer of 1981. It was thrilling to study and work alongside frighteningly smart people at the laboratory and on the campus. I experienced that same thrill returning last year, but with a new sense of urgency. Climate change is perhaps the most critical challenge facing humanity today and fusion energy—with millennia worth of clean fuel and no carbon emissions or nuclear waste—is the lasting solution that we need. Delivering it is the mission of PPPL.