For years, EMC2 Fusion Development Corp. has had to conduct its research into what’s known as Polywell fusion outside public view because the Navy wanted it that way. Now the Navy is phasing out its funding, and EMC2 Fusion is planning a three-year, $30 million commercial research program to see if its unorthodox approach can provide a fast track to cheap nuclear fusion power.
EMC2 Fusion’s latest findings on its Polwell approach are more positive than skeptics suspected but not as positive as some supporters hoped.
“This finding … is just one step along the way,” said M. Simon, a frequent contributor to the Talk-Polywell online discussion forum. “It makes the case that further experiments are warranted. In other words, no showstoppers.”
Nicholas Krall, a plasma physicist who has been working in the fusion field for more than a half-century and has been an adviser to EMC2 Fusion, was more enthusiastic. “I think this is the most exciting experimental advance that I’ve been involved in,” he told NBC News. ‘I’m stoked.”
EMC2 reports experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when beta (plasma pressure/magnetic field pressure) is order of unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high beta a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. The current experiment validates this theoretical conjecture for the first time and represents critical progress toward the Polywell fusion concept which combines a high beta cusp configuration with an electrostatic fusion for a compact, economical, power-producing nuclear fusion reactor.
The high-pressure confinement, also known as high-beta confinement, is what’s described in the ArXiv paper. One of the keys to solving that problem was to redesign the Wiffle-Ball to do away with the joints between the reactor’s rings, Park said.
However, the test device did not demonstrate the neutron production that would be required for an actual fusion reaction. “We tried to do it, but we just didn’t have enough equipment to do it,” Park said. “We thought that getting the Wiffle-Ball effect validated was a good accomplishment.”
Park is proud of the fact that his team proved the Wiffle-Ball design could work — confirming a theoretical claim that was first made 56 years ago by physicist Harold Grad. But EMC2 Fusion still has to show that the design can support a fusion reaction that eventually produces more power than is put into the system. Such a system would have to smash ions together in the center of a hot, magnetized cloud of electrons.
For the Navy-supported project, EMC2 Fusion concentrated on the prospects for an exotic kind of hydrogen-boron fusion known as pB11. But if the project goes commercial, the company would consider more mainstream options such as deuterium-tritium.
Park said he’s already been having discussions with potential backers for the next experimental phase.
“It’ll be great if we get funding,” he said. “But even if we don’t, I think there will be somebody who will be excited if they understand what all this means. There could be a bit of a race, too. If the race happens, I’m playing to win the race.”
Krall is anxious to see that race heat up. He acknowledged that EMC2 Fusion hasn’t yet determined whether or not a working Polywell fusion reactor is feasible — but at the age of 82, he’s counting on Park to get the answer to that question soon.
“He thinks we can reach break-even in seven years, and we can get to proof of principle in four years. Seven years, I can wait that long,” Krall told NBC News. “I’ve had a good career, but I’ll be a lot happier if I can see a break-even fusion device before I kick off.”
SOURCES – Arxiv, NBC New Alan Boyle, Talk Polywell