{"id":12463,"date":"2021-09-01T03:14:10","date_gmt":"2021-09-01T10:14:10","guid":{"rendered":"https:\/\/worldcampaign.net\/?p=12463"},"modified":"2021-09-03T03:26:29","modified_gmt":"2021-09-03T10:26:29","slug":"the-race-to-give-nuclear-fusion-a-role-in-the-climate-emergency-the-observer","status":"publish","type":"post","link":"https:\/\/worldcampaign.net\/?p=12463","title":{"rendered":"“The race to give nuclear fusion a role in the climate emergency”, The Observer"},"content":{"rendered":"

Arthur Turrell, London, 28 August 2021<\/p>\n

Power from fusion has proved too hard to generate at scale. Can recent breakthroughs and massive investment change that?<\/em><\/p>\n

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Physicist Vaughn Draggoo inspects the target chamber during its construction at the National Ignition Facility in Livermore, California, October 2001.<\/span> Photograph: Joe McNally\/Getty Images<\/figcaption><\/figure>\n<\/div>\n<\/div>\n<\/div>\n
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O<\/span><\/span>n 8 August 2021, a laser-initiated experiment at the United States National Ignition Facility (NIF), based at Lawrence Livermore National Laboratory in California, made a significant breakthrough<\/a> in reproducing the power source of the stars, smashing its own 2018 record for energy released from nuclear fusion reactions 23 times over. This advance saw 70% of the laser energy put in released as nuclear energy. A pulse of light, focused to tiny spots within a 10-metre diameter vacuum chamber, triggered the collapse of a capsule of fuel from roughly the size of the pupil in your eye to the diameter of a human hair. This implosion created the extreme conditions of temperature and pressure needed for atoms of hydrogen to combine into new atoms and release, kilogram for kilogram, 10m times the energy that would result from burning coal.<\/span><\/p>\n

The result is tantalisingly close to a demonstration of \u201cnet energy gain\u201d, the long sought-after goal of fusion scientists in which an amount greater than 100% of the energy put into a fusion experiment comes out as nuclear energy. The aim of these experiments is \u2013 for now \u2013 to show proof of principle only: that energy can<\/em> be generated. The team behind the success are very close to achieving this: they have managed a more than 1,000-fold improvement in energy release between 2011 and today. Prof Jeremy Chittenden, co-director of the Centre for Inertial Fusion Studies at Imperial College London, said last month<\/a> that \u201cThe pace of improvement in energy output has been rapid, suggesting we may soon reach more energy milestones, such as exceeding the energy input from the lasers used to kickstart the process.\u201d<\/p>\n

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If you\u2019re not familiar with nuclear fusion, it\u2019s different from its cousin, nuclear fission, which powers today\u2019s nuclear plants by taking big, unstable atoms and splitting them. Fusion takes small atoms and combines them to forge larger atoms. It is the universe\u2019s ubiquitous power source: it\u2019s what causes the sun and stars to shine, and it\u2019s the reaction that created most of the atoms we are made of.<\/p>\n

Scientists have long been excited about fusion because it doesn\u2019t produce carbon dioxide or long-lived radioactive waste, since the fuel it requires \u2013 two types of hydrogen known as deuterium and tritium \u2013 is plentiful enough to last for at least thousands of years, and because there is zero chance of meltdown. Unlike renewables such as wind and solar power, plants based on fusion would also take up little space compared with the power they would be able to generate.<\/p>\n

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The Tokamak of the Joint European Torus (Jet) at the Culham Science Centre \u2013 which will soon to attempt to produce the largest amount of fusion energy so far.<\/span> Photograph: AFP\/Getty Images<\/figcaption><\/figure>\n
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However, because the NIF\u2019s breakthrough is about demonstrating the principle only, the total amount of energy generated is not very impressive; it\u2019s only just enough to boil a kettle. Nor does the gain measurement account for the energy used to run the facility, just what\u2019s in the laser pulse. Despite this, it is nevertheless a landmark moment in the decades-long quest to produce fusion energy and use it to power the planet \u2013 which is, perhaps, the greatest scientific and technological challenge humanity has ever undertaken.<\/div>\n

Although the experiment may have happened in a vacuum, NIF\u2019s advance has not, and the pace of progress in fusion may surprise some long-time sceptics. Even Dr Mark Herrmann<\/a>, head of the NIF\u2019s fusion programme, says the latest development was \u201ca surprise to everyone\u201d. Many recent advances have been made with a different type of fusion device, the tokamak: a doughnut-shaped machine that uses a tube of magnetic fields to confine its fuel for as long as possible. China\u2019s Experimental Advanced Superconducting Tokamak (East) set another world record in May by keeping fuel stable for 100 seconds at a temperature of 120m degrees celsius \u2013 eight times hotter than the sun\u2019s core. The world\u2019s largest ever magnetic fusion machine, Iter, is under construction in the south of France and many experts think it will have the scale needed to reach net energy gain. The UK-based Joint European Torus (Jet), which holds the current magnetic fusion record for power of 67%, is about to attempt to produce the largest total amount of energy of any fusion machine in history. Alternative designs are also being explored: the UK government has announced plans for an advanced tokamak with an innovative spherical geometry, and \u201cstellarators<\/a>\u201d, a type of fusion device that had been consigned to the history books, are enjoying a revival having been enabled by new technologies such as superconducting magnets.<\/p>\n