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Tokamak Energy, based near Oxford, UK, has demonstrated a world-first with its privately-funded ST40 spherical tokamak. The reactor achieved a plasma temperature of 100 million degrees Celsius, the threshold required for commercial fusion energy.

At nearly seven times hotter than the centre of the Sun, this is by far the highest temperature ever generated within a spherical tokamak and also by any privately-funded tokamak. The ST40 had previously achieved a temperature of 15 million degrees in June 2018. While several government laboratories have reported plasma temperatures above 100 million degrees in conventional tokamaks, this milestone has been achieved in just five years, for a cost of less than £50m ($70m) and in a much more compact fusion device. This provides further proof that spherical tokamaks are a viable route to the delivery of clean, secure, low cost, scalable fusion energy.

A team of researchers from Lawrence Livermore National Laboratory, the University of California at Berkeley and Princeton University has developed plasma-based techniques to build a lens for laser beams with petawatt-scale power. In their paper published in the journal Physical Review Letters, the group describes the two techniques they developed.

Physicists conducting work with particle accelerators and fusion research efforts are hopeful that other researchers will build lasers that are more powerful than those currently available. Such work has been held up by the solid-state optics technology used to create lasers—giving them more power would damage the parts used to generate the laser, making them useless. In this new effort, the researchers noted that other researchers have found that plasma can be used to create optic components such as amplifiers and mirrors. They wondered if the same might be true for the kind of lens needed to produce extremely powerful laser beams. They came up with a concept that involved inducing patterns of high and low density in a given plasma. Light moving through it, they note, would experience a phase shift based on the density of the plasma.

The researchers did not actually build such a laser, but instead, proposed two ways that it might be built. The first method involved firing two pump lasers at a gas sample. The first laser ionized the gas into a plasma, while the second did not. The result was a plasma with a bulls-eye configuration of high and low-density plasma rings, which could be used as a laser lens.

If nuclear fusion reaction – the process that powers the Sun and other stars – could be used on a consistent basis on Earth, it would be a source of virtually unlimited clean energy. But there are still a lot of obstacles to overcome.

U.K.-based nuclear fusion firm Tokamak Energy has demonstrated a world-first with its privately-funded ST40 spherical tokamak, achieving a plasma temperature of 100 million degrees Celsius. This threshold is necessary for the future deployment of commercially successful fusion power. According to the company, this is by far the highest temperature ever achieved in a spherical tokamak and by any privately funded tokamak.

Several government laboratories have reported plasma temperatures above 100 million degrees in conventional tokamaks, including South Korea’s KSTAR reactor and China’s “artificial sun” EAST tokamak reactor. However, Tokamak Energy highlights that its milestone has been achieved in just five years, or a cost of less than £50m ($70m), in a much more compact fusion device. This achievement further substantiates spherical tokamaks as the optimal route to the delivery of clean, secure, low-cost, scalable, and globally deployable commercial fusion energy.

OXFORD, England 0, March 10, 2022 /PRNewswire/ — Tokamak Energy has demonstrated a world-first with its privately-funded ST40 spherical tokamak, achieving a plasma temperature of 100 million degrees Celsius, the threshold required for commercial fusion energy.

This is by far the highest temperature ever achieved in a spherical tokamak and by any privately funded tokamak. While several government laboratories have reported plasma temperatures above 100M degrees in conventional tokamaks, this milestone has been achieved in just five years, for a cost of less than £50m ($70m), in a much more compact fusion device. This achievement further substantiates spherical tokamaks as the optimal route to the delivery of clean, secure, low cost, scalable and globally deployable commercial fusion energy.

In findings that could help advance another “viable pathway” to fusion energy, research led by Lawrence Livermore National Laboratory (LLNL) physicists has proven the existence of neutrons produced through thermonuclear reactions from a sheared-flow stabilized Z-pinch device.

The researchers used advanced computer modeling techniques and diagnostic measurement devices honed at LLNL to solve a decades-old problem of distinguishing neutrons produced by thermonuclear reactions from ones produced by ion beam-driven instabilities for plasmas in the magneto-inertial fusion regime.

While the team’s previous research showed neutrons measured from sheared-flow stabilized Z-pinch devices were “consistent with thermonuclear production, we hadn’t completely proven it yet,” said LLNL physicist Drew Higginson, one of the co-authors of a paper recently published in Physics of Plasmas.

The superconducting magnet seen here could be the key ingredient in finally producing a commercial fusion reactor.

The magnet will be deployed in the SPARC tokamak developed by MIT which is currently under construction with a 2025 completion date.

A nuclear reactor at an Illinois energy plant is helping University of Chicago scientists learn how to catch and understand the tiny, elusive particles known as neutrinos.

At Constellation’s (formerly Exelon) Dresden Generating Station in Morris, Illinois, the team took the first measurements of neutrinos coming off a nuclear reactor with a tiny detector. These particles are extremely hard to catch because they interact so rarely with matter, but power reactors are one of the few places on Earth with a high concentration of them.

“This was an exciting opportunity to benefit from the enormous neutrino production from a reactor, but also a challenge in the noisy industrial environment right next to a reactor,” said Prof. Juan Collar, a particle physicist who led the research. “This is the closest that neutrino physicists have been able to get to a commercial reactor core. We gained unique experience in operating a detector under these conditions, thanks to Constellation’s generosity in accommodating our experiment.”

Do two promising structural materials corrode at very high temperatures when in contact with “liquid metal fuel breeders” in fusion reactors? Researchers of Tokyo Institute of Technology (Tokyo Tech), National Institutes for Quantum Science and Technology (QST), and Yokohama National University (YNU) now have the answer. This high-temperature compatibility of reactor structural materials with the liquid breeder—a lining around the reactor core that absorbs and traps the high energy neutrons produced in the plasma inside the reactor—is key to the success of a fusion reactor design.

Fusion reactors could be a powerful means of generating clean electricity, and currently, several potential designs are being explored. In a fusion reactor, the fusion of two nuclei releases massive amounts of energy. This energy is trapped as heat in a “breeding blanket” (BB), typically a liquid lithium alloy, surrounding the reactor core. This heat is then used to run a turbine and generate electricity. The BB also has an essential function of fusion fuel breeding, creating a closed fuel cycle for the endless operation of the reactors without fuel depletion.

The operation of a BB at extremely high temperatures over 1,173 K serves the attractive function of producing hydrogen from water, which is a promising technology for realizing a carbon-neutral society. This is possible because the BB heats up to over 1,173 K by absorbing the energy from the fusion reaction. At such temperatures, there is the risk of structural materials in contact with the BB becoming corroded, compromising the safety and stability of the reactors. It is thus necessary to find structural materials that are chemically compatible with the BB material at these temperatures.