Sunlight generates its energy by fusing two small atomic nuclei together; humans could mimic this process at power stations to generate abundant, clean electricity that could provide nearly limitless sources.
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| Nuclear Fusion: |
Scientists at Lawrence Livermore National Laboratory had successfully ignited nuclear fusion. But what does that really entail?
The ultimate source of energy or a pipe dream?
Scientists are exploring nuclear fusion as an energy source to power our sun and stars; an endeavor which would produce limitless, clean power; however, progress has been slow and frustrating. Fusion works by joining two hydrogen atoms together and producing deuterium isotope, which releases its stored energy at an exponentially greater rate than when introduced into fusion process - providing electricity, heat or propulsion power sources.
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But how can we produce self-sustaining fusion reactions on Earth to make this technology commercially viable? One hope lies with devices known as tokamaks or stellarators, which use magnetism to contain plasma of deuterium and tritium to achieve temperatures up to 100 million Kelvins (several times hotter than the core of our sun) needed for fusion reaction.
Fusion research is an international undertaking. The United States, Russia and China all maintain extensive programmes dedicated to it; additional vigorous work can also be found in Japan, the UK and Europe. In 2035, European Union's International Thermonuclear Experimental Reactor, or ITER should go fully into operation - though its director general Pietro Barabaschi recently advised against expecting full phase operation within weeks or months of starting construction work on ITER.
ITER's main challenge is reaching the necessary temperatures, which must remain steady long after hydrogen atoms fuse. A secondary objective is producing electricity which will offset the costs associated with producing plasma, while its third goal is harnessing fusion energy beyond electricity production and safely sourcing tritium from it.
Private fusion energy companies have emerged to try and expedite development of fusion energy, with some raising substantial capital. Helion Energy raised $570 million from investors including Sam Altman of OpenAI in 2021; they anticipate being able to demonstrate their technology at a demonstration plant by 2023.
Helion's seventh-generation machine, due to go live next year, will use pulsed high-power magnet technology in an effort to produce fusion energy. But Cowley cautions that it could take two or three decades before this technology becomes practical enough for incorporation in power stations.
The challenges
Stars produce tremendous amounts of energy by fusing hydrogen atoms into heavier helium isotopes that emit heat, producing vast quantities of heat energy that could potentially power an almost limitless source of clean and renewable power without emitting greenhouse gases or leaving long-lived radioactive waste behind. Harnessing that process in a reactor could provide nearly limitless clean power without emitting greenhouse gases or long-term radioactive waste - however it will present many challenges and be an enormous undertaking.
Fusion has long been one of the cornerstones of scientific inquiry. While hundreds of experimental reactors have been built worldwide, none has managed to keep its reaction going for more than a few seconds and generate more energy than it consumes. That might change soon: in France alone is underway construction on ITER -- likely its most advanced and groundbreaking yet project ever -- which promises to demonstrate whether sustained nuclear fusion can indeed become economically feasible.
However, to effectively control hydrogen fireballs within its confinement vessel and prevent hydrogen from collapsing into fireballs after each reaction cycle. Furthermore, magnetic fields more powerful than nuclear particles must confine fusion plasma within its reactor and remain confined within it for every reaction cycle. Furthermore, after every reaction cooled down after every cycle to prevent hydrogen fireballs bursting from its confinement vessel and blasting out into space.
Researchers are also exploring other fusion technologies, including "aneutronic" reactors that use heavier isotopes of hydrogen such as deuterium and tritium without producing neutrons - these may prove easier to build and operate than conventional reactors due to lower temperature requirements or denser plasma needs.
Even amid difficulties, science continues to advance. A team in Culham, England reported in February that they had succeeded in keeping a fusion reaction going for five seconds -- enough time to boil 60 kettles of water! Although this may not sound significant at first glance, given that preparation of their reactor and energy generation took months of work and preparation of necessary materials was required before being even close to reaching this stage of research.
But even if ITER succeeds, it won't be enough to demonstrate commercial-scale fusion power. Scientists must improve efficiency of experiments while simultaneously making them cheaper; additionally, they need a way of recovering energy used during fusion reactions that has been lost during conversion processes.
The opportunities
Nuclear fusion has the potential to become an environmentally-friendly source of renewable and limitless energy that could replace fossil fuels while simultaneously decreasing pollution-induced health problems. Requiring no mining or drilling for raw materials and producing no greenhouse gasses that contribute to global warming, nuclear fusion could produce hydrogen as the most abundant element on our universe and generate electricity without needing scarce uranium to generate electricity fusion can make hydrogen production viable for production purposes as well as providing clean electricity without mining for it on Earth.
Scientists seek to harness the power of fusion by building a reactor capable of supporting long-term fusion reactions; one in which energy generated exceeds what is consumed. ITER, a seven-nation project including United States, China, European Union Russia India and Japan alliance is trying to overcome past failures and build this kind of energy reactor.
One of the obstacles to fusion lies in its requirements that its plasma must be hotter than that found near the center of our Sun, and can only remain contained via immense magnetic fields. Seife takes us on an engaging tour through science, politics, and people involved with this most ambitious of projects, featuring daring geniuses such as Andrei Sakharov and Edward Teller; monomaniacal villains like Ronald Richter who embarrassed his country with false claims of success; Stanley Pons and Martin Fleischmann whose duplicity led to one of most well-known scientific scandals ever known today.
Fusion will require billions in funding and decades of experimentation, but there are encouraging signs that breakthrough may be nearer than we think. A recent announcement by the US Department of Energy that Lawrence Livermore National Laboratory scientists had achieved net energy from nuclear fusion was a notable milestone - this may herald a new era of reactors without radioactive waste production similar to fission reactors that currently power most global nuclear plants.
The science
Nuclear fusion provides the energy that fuels our Sun and other stars. This process occurs when hydrogen atoms fuse to form helium and release energy, which requires immense pressures and temperatures in order to overcome the positively charged electrostatic forces that normally prevent nuclear nuclei from uniting. Scientists have attempted to replicate this reaction for over 60 years on Earth; recently in California however a team announced that their experiment produced more energy than was consumed - an outstanding milestone achievement!
This experiment involved beaming 192 lasers at a small target in a vacuum chamber to generate heat for the NIF device to use to produce plasma - an ionised gas composed of hydrogen isotopes - from which collisions between particles produced more energy than they consumed, creating 1.5 megajoules faster than light could travel an inch.
While this accomplishment marks an impressive milestone, its commercial viability remains far off. Helion, the company behind this project, plans on creating a seventh-generation machine capable of producing electricity within one year - an ambitious target backed by over $5 billion from private investors including OpenAI founder Sam Altman himself.
!st fusion technology will likely take some time before becoming commercially viable energy source.
The primary obstacle in the way of creating self-sustaining fusion in a laboratory lies in its complexity: to do this requires close enough proximity between deuterium and tritium nuclei that their positive charges cancel each other out to release neutrons; something which requires tremendous temperatures and pressures which are hard to produce or sustain on Earth.
Financial and logistical barriers remain to wide-scale fusion research; yet the research community remains confident of its prospects of achieving it on a large scale. ITER's director general recently stated in a speech that, should plasma production start before 2025, operations could start within three decades - although he cautioned of its long journey toward creating carbon-free future.
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