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Scientists at the Lawrence Livermore National Laboratory in Northern California have announced that a record-shattering nuclear fusion experiment at the National Ignition Facility generated an astonishing 10 quadrillion watts of power in a fraction of a second! This miniature sun-like reaction may have also revealed to us the secret of a sustained fusion reaction: a self-heating or “burning” plasma composed of neutron-heavy hydrogen or deuterium within the fuel capsule is the key.
“A burning plasma is when heating from the fusion reactions becomes the dominant source of heating in the plasma, more than required to initiate or jump-start the fusion,” Annie Kritcher, a physicist at the Lawrence Livermore National Laboratory (LLNL), told Live Science
The process they use to make this happen is absolutely insane, but they can use it to create about 10% of all the energy the Earth receives from the sun for about 100 trillionths of a second from a one-millimeter fuel source being pounded by 192 of the most powerful precision lasers in the world. Whenever the system fires (which is only about once a day) it consumes 400 Megajoules of energy, that’s about 1/10th of what it takes to power Miami, Florida.
According to Space.com, “The researchers said the reaction blasted out that much energy because the process of fusion itself heated the remaining fuel into a plasma hot enough to enable further fusion reactions.”
Fusion Is No Longer A Crazy Idea
Nuclear fusion occurs naturally in stars all over the galaxy and differs significantly from the fission we use to power our nuclear reactors on Earth. Instead of splitting atoms apart we’re merging them or ‘fusing’ them. Typcial fusion is powered by hydrogen fusing into helium, but this requires the immense gravitational pressure of a sun to happen naturally.
On Earth, those pressures are unimaginably unreachable. But what we can do is provide heat through highly focused and powerful lasers which is another route according to Gay-Lussac’s law (*In a given volume as the temperature increases so does pressure. It works in reverse too.) So that being said, if you can’t create pressure but you can create temperature, you just have to figure out how to do it safely.
Scientists’ solution to that is ‘inertial confinement’. Space.com reported that through the shaping of the fuel capsule made of polycarbonate diamond and a small cylinder of depleted uranium lined with gold called a hohlraum (this is a crazy expensive process) they were able to make the capsule expand outward while the fuel pellet “implodes” making the fuel fuse with such intense heat that it created its own plasma by melting the rest of the pellet.
“This is significant as it is a necessary step on the way to producing large amounts of energy from fusion relative to the energy we put in,” physicist Alex Zylstra told Live Science
“Burning plasmas [at] NIF are now in a new regime where we can scientifically study such conditions,” Zylstra said.
“This work is important as it provides access to a new regime of plasma physics which will provide a wealth of understanding for the entire fusion community,” she said.
