Startup Seeks to Enable Pulsed Fusion

Article By : Maurizio Di Paolo Emilio

Startup First Light Fusion is demonstrating a 'Big Gun' device it hopes will advance the renewable energy source.

Development of new fusion energy schemes now includes a U.K. effort that uses high-compression inertial confinement to generate power via the fusing of atoms.

First Light Fusion completed development of its “Big Gun” fusion device in May, and has since finished testing and commissioning. At 22 meters in length and 25,000 kg in weight, Big Gun is considered the largest of its kind in the U.K. First Light Fusion was spun out from the University of Oxford. It employs a team of engineers and physicists, and works closely with university researchers.

The Oxford-based startup’s approach is based on an inertial confinement, which seeks to achieve fusion conditions by exposing fusion fuel to extremely high compression in a very short time. The approach uses the inertia of the fuel itself to maintain those conditions long enough to trigger a fusion reaction. Company founder Nick Hawker published a peer-reviewed paper in the Philosophical Transactions of the Royal Society showing that inertial confinement fusion could provide energy at prices competitive with existing renewables.

Gianluca Pisanello, the startup’s chief operating officer, said fusion is increasingly being seen as a future source of clean, base-load power. “It is a fact that we do not yet have a ‘market-ready’ fusion energy solution,” Pisanello said in an interview. “Until that happens, we will still be a future technology, while renewables like wind and solar are being rolled out worldwide.

“People are often risk-averse,” he added. “But without someone taking risks and achieving hard things, we would not now have the technologies that are shouldering the current decarbonization efforts. Solar, wind, and battery didn’t look like they had a chance two decades ago, and even a decade ago, they didn’t look like they could compete on price.”

U.K. fusion investments include a more than £200 million award for a Spherical Tokamak for Energy Production (STEP) project aimed at developing a commercially viable fusion power plant by 2040. Pisanello also noted growing private investment, with more than 30 companies pursuing different fusion technologies.

First Light Fusion’s Gianluca Pisanello.

First Light Fusion’s approach to inertial fusion aims to create the extreme temperatures and pressures required by compressing a target using a high-speed projectile. “In comparison with the vastly complex machines required for the more common magnetic fusion [like France’s ITER], First Light’s equipment is relatively simple,” said Pisanello. The approach would allow existing power plant operators to design and build plants based on its technology.

The U.K. startup’s scheme attempts to reduce the time required to achieve a temperature constant equivalent to a fraction of a second. It accomplishes this by directing the fuel toward a projectile. The framework also addresses some of the challenges associated with building fusion reactors.

Among fusion energy’s advantages over conventional fission power plants are reduced radioactive waste, the elimination of weapon-grade materials and no meltdown risk since fusion is not a chain reaction.

Pisanello and other proponents note that fusion power would help early adopters achieve targeted reductions in carbon emissions. They site advances such as a successful fusion reaction demonstration at Lawrence Livermore Laboratory’s National Ignition Facility (NIF).

First Light Fusion’s approach differs from the NIF’s in how the input energy is provided to compress fuel pellets to create fusion conditions. NIF employs multiple-direction lasers, whereas First Light employs a single-sided impact.

That approach address three potential “showstoppers,” Pisanello said: “managing the intense heat flux, preventing neutron damage to structural materials and generating the required tritium fuel.” The resulting benefits include “physical separation between the driver and the area where the fusion energy is released. Furthermore, this separation decouples the physics problem of the fusion process from the engineering ones, thereby allowing faster iterations in the fusion research and giving more flexibility in the design of the reaction vessel.”

Hypervelocity

Big Gun complements the startup’s Machine 3 electromagnetic launch device that allows projectiles to be launched at different velocities. The hypervelocity gas gun is housed in a 10-mm steel-clad structure called Citadel. Using about 3 kg of gun powder, projectiles can achieve a maximum velocity of more than 6.5 km/s, or 14,500 mph.

Projectiles are launched into a vacuum chamber containing a fusion target. Leveraging the startup’s amplification technology, the collapse velocity of the fusion fuel reaches more than 70 km/s, producing pressure 30 times greater than the center of Earth, thereby creating the conditions necessary for fusion. A series of launches is intended to demonstrate the inertial confinement approach. The goal is creating the extreme temperatures and pressures needed for fusion by compressing fuel using a hyper-speed projectile.

Along with the fusion demonstration, the startup is accelerating other workflows. “These include planning for our prototype gain-scale experiment and further grid-scale reactor development,” Pisanello added. It has also expanded its Oxford headquarters to accommodate its growing team of scientists and engineers along with new equipment.

Fusion infrastructure. (Source: First Light Fusion)

Energy demand

Global power demand is expected to double by 2040, and could increase five-fold by 2060 as electrification expands to new applications.  Pisanello said research commissioned by First Light Fusion found that 19,900 TWh per year could be generated from wind and solar by 2040, an eight-fold increase that would still meet less than half of projected demand. “Wind and solar power alone will not be able to meet projected energy demand, opening up a market for clean, base-load power to complement them. This is where fusion energy will play a key role,” he argued.

Indeed, fusion efforts are gaining traction as the need grows to reduce carbon emissions from power systems. “We firmly believe that clean energy sources should complement, not exclude, one another.”

The fusion startup asserts that decarbonizing the power system based primarily on wind and solar would only be achieved if global energy demand remained flat. “If power demand booms in the next two decades, as it is projected to do, especially in geographies with fast-growing populations and economies, then we will need new sources of clean power generation,” Pisanello said.

This article was originally published on EE Times.

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