News & Events

A leading fusion expert retires from the UW

Amy Sprague
June 1, 2020

Driven to work through the remaining hurdles of affordable fusion energy, Tom Jarboe has just about got us there.

Tom Jarboe

By many accounts, UW aeronautics and astronautics professor Tom Jarboe’s decades-long relentless focus is largely responsible for bringing affordable fusion energy tantalizingly close to market. His dedication is understandable, because fusion, once some of the stickier details are worked out, promises an unlimited source of zero-emission energy with no long-lived hazardous waste. Proving that fusion energy can be produced on a municipal level with a similar cost profile as coal-fired power plants, as Jarboe and his colleagues are doing, is the holy grail of the future of energy.

We take a look at Jarboe's storied career, contributions toward a fusion future and exceptional intuition as he retires from the UW.

Jarboe’s commitment to fusion came early. He was a “youngster,” as he says, on an Illinois farm when the first hydrogen bomb was detonated in 1952. He “just thought we ought to figure out how to use all that energy for humanity.”

He enrolled at the University of Illinois where he reports to have had the biggest transformation of his life, entering as a farm boy and graduating as a physicist. He has worked on fusion ever since, earning a doctorate at Berkeley and moving on to Los Alamos National Lab (LANL).

Working through fusion challenges

Jarboe first began working on the spheromak concept for fusion energy in 1979 when it was proposed by physicists at the Princeton Plasma Physics Laboratory (PPPL). While little was known how to form or sustain a spheromak, Jarboe led his team at Los Alamos National Laboratory to many firsts in sustaining a spheromak, an essential stepping stone toward affordable energy production. Fusion laboratories around the world adapted his designs in their own research.

Tom Jarboe

Spheromaks are compact, doughnut-shaped magnetic vessels that confine plasma to undergo fusion at about 150 million degrees Celsius. Here, Jarboe is sitting in front of the HIT-SI3 Sustained Spheromak Experiment.

When Los Alamos stopped funding spheromak research in 1989, Jarboe moved to the UW to continue this research and also apply it to the tokamak, a related confinement device for thermonuclear fusion.

During this time at the UW, Jarboe made several advances in the confinement of plasma, which is predictably really hard to do given the temperatures plasma reaches, and the sustainment of a fusion plasma through helicity injection, or adding a corkscrew-like spin, which is being further advanced at PPPL, among other labs. His 1994 paper, “Review of spheromak research,” is considered the seminal paper on the subject and is still referenced frequently today.

Arguably, his most recent influential discovery is the Imposed-Dynamo Current Drive (IDCD), a method to inject magnetic energy and helicity into a plasma confinement chamber in a spheromak, which builds and sustains a stable spheromak better than any other method. Jarboe’s IDCD discovery makes possible cost-competitive fusion energy on a municipal scale.

Jarboe’s IDCD discovery makes possible cost-competitive fusion energy on a municipal scale.

With this breakthrough, Jarboe founded UW spinoff company CTFusion with then-doctoral student Derek Sutherland in 2015, now a spheromak leader himself. Several others from Jarboe’s lab have since joined the company. The company is preparing to construct a larger fusion reactor to reach higher temperatures as proof of concept, another major step towards the commercialization of fusion energy for power grids. Jarboe will continue the march toward affordable fusion energy at CTFusion.

The drive, intuition and motivation behind the physicist

In speaking to Jarboe’s colleagues from all stages of his career, his unique drive and intuition were repeated themes. Jarboe, it seems, has had an intuition about spheromaks that far preceded any proven physics. He has been working since 1979 to prove it. As the commitment to spheromaks fell in and out of favor with the Department of Energy and the national labs, Jarboe was not swayed. The stakes were too high as the world needs sustainable, safe energy production, and the spheromak is Jarboe’s horse in the race.

To Jarboe, advancing knowledge is making a good guess into the unknown and then doing an experiment to prove it.

Juan Fernandez, who worked under Jarboe at LANL, said, “Tom is one of the most intuitive people I’ve ever met. There are people who arrive at their conclusions through mathematical calculations. But Tom understood what the answer was before he could prove it. Not to say he wasn’t rigorous. He created experiments that would produce the weight of evidence. Everything Tom said you could take to the bank because it was supported by data and incontrovertible. Not every experiment would turn out as he expected, but he would tell the truth whether his results supported his hunch or not.”

Tom is one of the most intuitive people I’ve ever met. There are people who arrive at their conclusions through mathematical calculations. But Tom understood what the answer was before he could prove it. - Juan Fernandez

Jarboe’s A&A colleague professor Uri Shumlak reports that Jarboe tells him to “keep a young mind,” which Shumlak interprets as being open to new ideas that challenge your current understanding. It makes sense that this advice came from Jarboe, who is known for pushing his unconventional thinking. 

Last year, Jarboe’s intuition and observations of the instability of plasma through this spheromak research led him to publish a new model of solar behavior that solves the puzzle of the 11-year sunspot cycle. While Jarboe’s teaching schedule may be freed up next year, we are looking forward to seeing the hunches and intuitions he will be moving forward to advance our understanding of the universe as professor emeritus and continuing as president of CTFusion.

A special thank you to those interviewed for this piece: Paul Bellan (CalTech), Mike Brown (Swarthmore),Thomas Dolan (University of Illinois), Juan Fernandez (LANL), Ken Fowler (Berkeley), Bick Hooper (Lawrence Livermore National Laboratory), Aaron Hossack (UW / CTFusion), George Marklin (UW), Roger Raman (UW), Uri Shumlak (UW) and Derek Sutherland (UW / CTFusion).