nuclear fusion

24 Articles

ITER Dreams And The Practical Reality Of Making Nuclear Fusion Work On Earth

July 6, 2023 by 52 Comments

Doing something for the first time is tough. Yet to replicate the nuclear fusion process that powers the very stars, and do it right here on Earth in a controlled and sustained fashion is decidedly at the top of the list of ‘tough’ first times. What further complicates matters is when in order to even get to this ‘first’ you also add in a massive, international construction project and a heaping of geopolitics, all of which is a far cry from past nuclear fusion experiments.

With the International Thermonuclear Experimental Reactor (ITER) as the most visible part of nuclear fusion research, it is perhaps little wonder that the recent string of delays and budget increases is leading some to proclaim doom and gloom over the entire sector. This ironically in contrast with the recent news from the US’s NIF and its laser-based inertial confinement fusion, which is both state-funded and will never produce commercial power.

In light of this, it feels pertinent to ask the question of whether ITER is the proverbial white elephant, or even the mausoleum of international science that a recent article in Scientific American makes it out to be. Is fusion research truly doomed to peter out amidst the seemingly never-ending work on ITER?

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Laser Fusion Ignition: Putting Nuclear Fusion Breakthroughs Into Perspective

December 19, 2022 by 45 Comments

This month the media was abuzz with the announcement that the US National Ignition Facility (NIF) had accomplished a significant breakthrough in the quest to achieve commercial nuclear fusion. Specifically, the announcement was that a net fusion energy gain (Q) had been measured of about 1.5: for an input of 2.05 MJ, 3.15 MJ was produced.

What was remarkable about this event compared to last year’s 1.3 MJ production is that it demonstrates an optimized firing routine for the NIF’s lasers, and that changes to how the Hohlraum – containing the deuterium-tritium (D-T) fuel – is targeted result in more effective compression. Within this Hohlraum, X-rays are produced that serve to compress the fuel. With enough pressure, the Coulomb barrier that generally keeps nuclei from getting near each other can be overcome, and that’s fusion.

Based on the preliminary results, it would appear that a few percent of the D-T fuel did undergo fusion. So then the next question: does this really mean that we’re any closer to having commercial fusion reactors churning out plentiful of power?

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Plasma Channel Shows Off A Remarkably Stylish Fusor

October 27, 2022 by 19 Comments

We’ve seen our fair share of Farnsworth–Hirsch fusors over the years — these high-voltage devices can get ions cooking to the point of achieving nuclear fusion even on a hobbyist’s budget, and even though they won’t solve the world’s energy problems, they certainly make for an impressive light show. While “simple” to build in the relative sense, the examples we’ve seen in the past have still been bulky contraptions supported by a cart full of complex gear befitting a nuclear reactor.

Which is why the fusor [Jay Bowles] recently completed is so impressive. As you can see in the latest Plasma Channel video which we’ve placed below the break, this desktop “star in a jar” not only features an incredibly low part count, but looks more like a movie prop than anything you’d expect to find in a physics lab. If you ever considered building a fusor of your own but were put off by the size and complexity of existing designs, you’ll definitely want to check this out.
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Thirty Seconds At 100 Megakelvins

January 16, 2022 by 28 Comments

Back in Dec 2020 we wrote about the Korea Superconducting Tokamak Advanced Research (KSTAR) magnetic fusion reactor’s record-breaking feat of heating hydrogen plasma up to 100 megakelvins for 20 seconds. Last month it broke its own record, extending that to 30 seconds. The target of the program is 300 seconds by 2026. There is a bit of competition going, as KSTAR’s Chinese partner in the International Thermonuclear Experimental Reactor (ITER), the Experimental Advanced Superconducting Tokamak (EAST) did a run a week later reaching 70 million degrees for 1056 seconds. It should be noted that KSTAR is reaching these temperatures by heating ions in the plasma, while EAST takes a different approach acting on the electrons.

The news reports seem to be using Celsius and Kelvins interchangeably, but at millions of degrees, that’s probably much smaller than measurement error. These various milestones are but stepping stones along the path to create a demonstration large fusion reactor, the goal of the global ITER mega-project. Currently China, the EU including Switzerland and the UK, India, Japan, Russia, South Korea, and the United States are members of ITER, and Australia, Canada, Kazakhstan, and Thailand are participants. The ITER demonstration reactor is being constructed at the Cadarache facility located 60 km northeast of Marseille, France, and is on track for commissioning phase to begin in 2025, going operational ten years later.

Image of CFS's SPARC reactor

Commonwealth Fusion’s 20 Tesla Magnet: A Bright SPARC Towards Fusion’s Future

September 27, 2021 by 62 Comments

After decades of nuclear fusion power being always ten years away, suddenly we are looking at a handful of endeavours striving to be the first to Q > 1, the moment when a nuclear fusion reactor will produce more power than is required to drive the fusion process in the first place. At this point the Joint European Torus (JET) reactor holds the world record with a Q of 0.67.

At the same time, a large international group is busily constructing the massive ITER tokamak test reactor in France, although it won’t begin fusion experiments until the mid-2030s. The idea is that ITER will provide the data required to construct the first DEMO reactors that might see viable commercial fusion as early as the 2040s, optimistically.

And then there’s Commonwealth Fusion Systems (CFS), a fusion energy startup.  Where CFS differs is that they don’t seek to go big, but instead try to make a tokamak system that’s affordable, compact and robust. With their recent demonstration of a 20 Tesla (T) high-temperature superconducting (HTS) rare-earth barium copper oxide (ReBCO) magnet field coil, they made a big leap towards their demonstration reactor: SPARC.

A Story of Tokamaks

CFS didn’t appear out of nowhere. Their roots lie in the nuclear fusion research performed since the 1960s at MIT, when a scientist called Bruno Coppi was working on the Alcator A (Alto Campo Toro being Italian for High Field Torus) tokamak, which saw first plasma in 1972. After a brief period with a B-revision of Alcator, the Alcator C was constructed with a big power supply upgrade. Continue reading “Commonwealth Fusion’s 20 Tesla Magnet: A Bright SPARC Towards Fusion’s Future” →

Fusion Ignition: What Does The NIF’s 1.3 MJ Yield Mean For Fusion Research?

August 30, 2021 by 37 Comments

Earlier this month, Lawrence Livermore National Laboratory (LLNL) announced to the world that they had achieved a record 1.3 MJ yield from a fusion experiment at their National Ignition Facility (NIF). Yet what does this mean, exactly? As their press release notes, the main advancement of these results will go towards the US’s nuclear weapons arsenal.

This pertains specifically to the US’s nuclear fusion weapons, which LLNL along with Los Alamos National Laboratory (LANL) and other facilities are involved in the research and maintenance of. This traces back to the NIF’s roots in the 1990s, when the stockpile stewardship program was set up as an alternative to nuclear weapons testing. Much of this research involves examining how today’s nuclear weapons degrade over time, and ways to modernize the existing arsenal.

In light of this, one may wonder what the impact of these experimental findings from the NIF are beyond merely ensuring that the principle of MAD remains intact. To answer that question, we have to take a look at inertial confinement fusion (ICF), which is the technology at the core of the NIF’s experiments.

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Fueling Up For Fusion: MAST’s Super-X, JET’s Deuterium-Tritium Experiments For ITER, And More

June 2, 2021 by 38 Comments

We’ve had nuclear fission reactors in operation all over the world for ages, but nuclear fusion always seems to be a decade or two away. While one cannot predict when we’ll reach the goal of sustained nuclear fusion, the cutting edge in test hardware is advancing at a rapid pace that makes us optimistic. Beginning as soon as this month and extending over a few years, we’re living through a very exciting time for nuclear fusion and plasma physics.

The Mega Ampere Spherical Tokamak (MAST) got a big upgrade to test a new cooled divertor design. JET (Joint European Torus) will be testing the deuterium-tritium fuel mixture that will be powering the ITER (the research project whose name began as an acronym for International Thermonuclear Experimental Reactor but has since been changed to just ITER). And the Wendelstein 7-X stellarator is coming back online with upgraded cooled divertors by next year.

Here the MAST Upgrade’s Super-X divertors have so far shown a ten-fold decrease in the temperature which the divertor is exposed to while carrying thermal energy out of the tokamak reactor. This means a divertor design and ultimately a fusion reactor that will last longer between maintenance sessions. On the stellarator side of things, Wendelstein 7-X’s new divertors may allow it to demonstrate the first continuous operation of a stellarator fusion reactor. Meanwhile, JET’s fuel experiments should allow us to test the deuterium-tritium fuel while ITER is working towards first plasma by 2025.

Continue reading “Fueling Up For Fusion: MAST’s Super-X, JET’s Deuterium-Tritium Experiments For ITER, And More” →