{"id":14384,"date":"2022-07-04T00:00:00","date_gmt":"2022-07-03T22:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/?post_type=purple_issue&p=14384"},"modified":"2022-09-16T09:05:32","modified_gmt":"2022-09-16T07:05:32","slug":"the-new-age-of-fusion","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/2022\/07\/04\/the-new-age-of-fusion\/","title":{"rendered":"The new age of fusion"},"content":{"rendered":"\n

THE NEW AGE OF FUSION<\/h2>\n\n

FOR DECADES, THE TECHNOLOGY TO DEVELOP CLEAN, SAFE FUSION POWER HAS REMAINED TANTALISINGLY OUT OF REACH. NOW, THOUGH, A NEW BREED OF START-UPS COULD HAVE CRACKED IT AT LAST. WILL WE FINALLY BE ABLE TO WAVE GOODBYE TO FOSSIL FUELS? <\/p>\n\n

by DR STUART CLARK <\/strong><\/p>\n\n

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The JET fusion reactor in Culham, Oxfordshire<\/figcaption><\/figure>\n\n

Flick through any collection of popular science magazines from the last 50 years and the chances are that you will encounter a feature about nuclear fusion. <\/p>\n\n

Nuclear fusion is the process of joining lightweight atoms together to release energy; it is the reason the Sun and the rest of the stars shine, and recreating that process on Earth promises an abundant form of low-carbon energy. <\/p>\n\n

As you look through the archival material, keep an eye open for when the pundits think fusion might arrive. It\u2019s an old joke that whatever the decade of the publication, fusion has always been \u201cabout 20 years away\u201d. Yet despite five decades of effort, no fusion plant can yet produce more energy than it takes to start the reaction. <\/p>\n\n

But don\u2019t let that bare fact make you think that fusion is as far away as ever. There has been a sea change recently that has shrunk the 20-year horizon to a mere decade away. <\/p>\n\n

For a start, there has been an increase in our understanding of the science of fusion. Second, there has been an undoubted set of technological breakthroughs. But it is the third reason that may be the deciding factor: a change in mindset. <\/p>\n\n

\u201cThe most important single thing that\u2019s changed in the world of fusion, in my opinion, over the last decade, is the very clear realisation that we need fusion,\u201d says Tim Bestwick. He is the chief technology officer and director of strategy, communications and business development at the UK Atomic Energy Association (UKAEA). <\/p>\n\n

\u201cTHE MOST IMPORTANT SINGLE THING THAT\u2019S CHANGED IN THE WORLD OF FUSION, IN MY OPINION, OVER THE LAST DECADE, IS THE VERY CLEAR REALISATION THAT WE NEED FUSION\u201d<\/p><\/blockquote>\n\n

He explains that the two principal factors in this realisation are climate change and energy security. In regard to climate change, fusion offers an abundant source of low-carbon energy that can be used in combination with renewable energy sources such as solar and wind power. This has been accepted for years now, and while energy security has also been talked about for a long time, the sharp need for it has only just recently come into focus, particularly with Russia\u2019s invasion of Ukraine causing many countries to rethink how they buy in energy and fuel from foreign powers. This all loads the dice in favour of fusion. <\/p>\n\n

The UK\u2019s fusion effort is headquartered at the Culham Centre for Fusion Energy in Oxfordshire. This is the home of a long-running experimental fusion reactor called JET, the Joint European Torus. JET is a tokamak, a five-metre-wide doughnut-shaped vessel. The name derives from a Russian word meaning \u2018toroidal chamber with magnetic field\u2019. Since starting operations in 1983, it has made major advances in understanding both the science of nuclear fusion and the engineering required to make it happen. And for inspiration, the researchers need only look up into the sky\u2026<\/span><\/p>\n\n

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The ITER tokamak is currently under construction in France <\/figcaption><\/figure>\n\n
CREATING THE SUN ON EARTH <\/h5>\n\n

The Sun is the nearest natural fusion reactor to Earth. Deep below its glowing surface, the temperature soars to 15 million degrees Celsius, and the pressure and density is similarly gigantic. <\/p>\n\n

Under these conditions, fusion naturally occurs. It starts with hydrogen and proceeds through a series of interactions that force the hydrogen nuclei together. First the reactions build isotopes of hydrogen and helium, and then ordinary helium itself. <\/p>\n\n

For an artificial fusion reactor, it is impossible to recreate the kinds of pressures and densities found inside the Sun. Inside JET, for example, the gas density rarely rises above that of the ordinary air outside, and so to compensate, the temperature must be boosted to more than 100 million degrees Celsius. At such temperatures, the gas becomes electrically charged. This state of matter is known as a plasma, and because of its electrical charge, it can be controlled by magnetic fields. The magnetic field is essential because no material can contain a gas at more than 100 million degrees Celsius. The magnetic field accelerates and controls the flow of the plasma within the reactor, allowing the particles to fuse and release energy. <\/p>\n\n

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A technician operates JET\u2019s remotely controlled MASCOT robotic arm<\/figcaption><\/figure>\n\n

\u201cJET has been an extraordinary machine. It has hugely outlived its expected life. I think its significance is around the fact that it is a deuterium-tritium machine,\u201d says Bestwick.<\/p>\n\n

Deuterium and tritium (DT) are isotopes of hydrogen. After a number of experiments at JET over the years, it\u2019s clear that deuterium and tritium will be the fuels that make fusion viable. So now that the science is sorted, the next step is for the engineers to actually build a reactor capable of generating more energy than it needs to run. This is where ITER comes in. <\/p>\n\n

ITER is a tokamak twice the diameter of JET. It is being built in southern France by a consortium of 35 countries, including the UK. The tokamak itself is scheduled to be completed this year, but then it must be encased in its surrounding machinery. Operation is expected to begin in 2025, followed by a decade of gradually ramping up the reactor to its full capacity. Eventually, ITER is expected to be able to return 10 times the energy required to start the process. <\/p>\n\n

Beyond ITER, UKAEA is also designing a reactor called STEP (Spherical Tokamak for Energy Production) that will be the world\u2019s first prototype nuclear fusion energy plant. The site for its construction will be chosen by the end of this year. Construction is slated to begin in the 2030s, with commissioning several years later. And they are not alone. <\/p>\n\n

SHARING KNOWLEDGE<\/h5>\n\n

The diffusion of knowledge about what it takes to spark fusion, combined with the march of technological progress, mean that building a commercial fusion power plant is now largely an engineering challenge, rather than a leap into the scientific research and development. As a result, the last few years have seen a profusion of private companies interested in developing their own approaches to fusion.<\/span><\/p>\n\n

\u201cTwenty years ago, fusion was the preserve of governments. Now there are more than 25 private fusion companies around the world and they\u2019re attracting huge amounts of investment,\u201d says Valerie Jamieson, who manages the newly inaugurated Fusion Cluster at Culham. <\/p>\n\n

Aiming for its official launch later this year, the Fusion Cluster is attracting start-up companies interested in building or contributing to fusion reactors. They will be housed next to JET\u2019s facilities, allowing expertise and opportunities to build up in one place. It\u2019s a tried and tested formula. <\/p>\n\n

\u201cThe best-known technology cluster is Silicon Valley,\u201d says Jamieson, \u201cHaving all your customers and collaborators nearby just oils the wheels and makes everything run more smoothly.\u201d <\/p>\n\n

Another UK science cluster exists at the Harwell Science and Innovation Campus, also in Oxfordshire. It started around a decade ago with a handful of companies and now boasts more than 100 space organisations. Of course, when it comes to private space companies, the most obvious success story is Elon Musk\u2019s SpaceX, which now routinely ferries astronauts to and from the International Space Station. This is the sort of success that the cluster hopes to emulate.<\/span><\/p>\n\n

\u201cTWENTY YEARS AGO, FUSION WAS THE PRESERVE OF GOVERNMENTS. NOW, THERE ARE MORE THAN 25 PRIVATE FUSION COMPANIES AROUND THE WORLD\u201d<\/p><\/blockquote>\n\n

The successes have already begun for two of the more established companies in the cluster. <\/p>\n\n

Tokamak Energy (see Case Study 2) recently achieved the necessary plasma temperature for fusion in their one-metre-wide reactor, and First Light Fusion (see Case Study 1) achieved fusion for the first time using a different approach from tokamaks.<\/p>\n\n

And it is not just reactor companies that the cluster wants to attract. It also wants companies that can provide essential services for the reactors. Two of those essential services are robotics and artificial intelligence. <\/p>\n\n

<\/div>
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CASE STUDY 1: FIRST LIGHT <\/span><\/strong><\/h4>\n\n\n\n
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IMPLODING FUEL TO RELEASE ENERGY <\/span><\/h5>\n\n\n\n

There are a number of approaches to nuclear fusion. Beyond the swirling plasmas of the tokamaks, another approach is called \u2018inertial fusion\u2019. In this method, a fuel pellet is compressed to temperatures and densities that allow fusion to take place. <\/p>\n\n\n\n

At the National Ignition Facility (NIF) in the US, the compression is achieved by a bank of 192 extraordinarily powerful lasers. At First Light Fusion, a private company that is part of the Culham fusion cluster, it is achieved by shooting a target containing the fuel with a projectile fired from a hyper-velocity gun. The projectile is accelerated to 6.5 kilometres per second, but when it hits the target, the top secret design focuses and amplifies the impact to make the fuel implode at over 70 kilometres per second. This triggers fusion and releases a pulse of energy.<\/p>\n\n\n\n

First Light founder Nicholas Hawker heard about fusion while doing his A-Levels in the early 2000s, but it was not until his PhD that he took up the mantle to study how to advance inertial fusion, which back then was a completely new approach. \u201cBeing off the edge of the map and finding new ways of doing things is what really appealed to me,\u201d says Hawker. <\/p>\n\n\n\n

Now that the technology has been shown to work, First Light is designing a demonstrator reactor to be built in the second half of the 2020s. First Light is also working towards completing a pilot power plant in the 2030s, in line with other fusion start-ups and government-run initiatives.<\/p>\n<\/div><\/section>\n\n

HELPING HAND<\/h5>\n\n

Just across the campus from JET is the UKAEA\u2019s Remote Applications in Challenging Environments (RACE). Inside their hangar-like work area, a giant robotic arm is being tested. Once the reactors are up and running, humans will not be able to enter the reactors to perform maintenance. This is because deuterium-tritium fusion produces its energy in the form of neutrons, which create high levels of short-lived radiation. So robots will perform the tasks that humans cannot. This already happens at JET, where a 12-metre-long robotic arm with two \u2018hands\u2019 is remotely operated by a team of technicians. Called MASCOT, it can snake its way into the tokamak and replace wall tiles, tighten screws or remove worn components. <\/span>While the technicians are highly skilled at controlling the arm \u2013 they play Jenga <\/em>with it as part of their training \u2013 it is still a slow process. Therefore, similar but more sophisticated devices for ITER will be needed.<\/span><\/p>\n\n