Scientists
have moved a step closer to achieving sustainable nuclear fusion and almost
limitless clean energy
theguardian.com,
Ian Sample, science correspondent, Wednesday 12 February 2014
![]() |
The sun is powered by nuclear fusion, which smashes hydrogen nuclei together to make helium. Photograph: EPA/Corbis |
US
researchers have achieved a world first in an ambitious experiment that aims to
recreate the conditions at the heart of the sun and pave the way for nuclear
fusion reactors.
The
scientists generated more energy from fusion reactions than they put into the
nuclear fuel, in a small but crucial step along the road to harnessing fusion
power. The ultimate goal – to produce more energy than the whole experiment
consumes – remains a long way off, but the feat has nonetheless raised hopes
that after decades of setbacks, firm progress is finally being made.
Fusion
energy has the potential to become a radical alternative power source, with
zero carbon emissions during operation and minimal waste, but the technical
difficulties in demonstrating fusion in the lab have so far proved
overwhelming. While existing nuclear reactors generate energy by splitting
atoms into lighter particles, fusion reactors combine light atomic nuclei into
heavier particles.
In their
experiments, researchers at the National Ignition Facility at the Lawrence
Livermore National Laboratory in California use a bank of 192 powerful lasers
to crush a minuscule amount of fuel so hard and fast that it becomes hotter
than the sun.
The process
is not straightforward. The lasers are fired into a gold capsule that holds a
2mm-wide spherical pellet. The fuel is coated on the inside of this plastic
pellet in a layer as thin as a human hair.
When the
laser light enters the gold capsule, it makes the walls of the gold container
emit x-rays, which heat the pellet and make it implode with extraordinary
ferocity. The fuel, a mixture of hydrogen isotopes called tritium and
deuterium, partially fuses under the intense conditions.
The
scientists have not generated more energy than the experiment uses in total.
The lasers unleash nearly two megajoules of energy on their target, the
equivalent, roughly, of two standard sticks of dynamite. But only a tiny
fraction of this reaches the fuel. Writing in Nature, the scientists say fusion
reactions in the fuel released at best 17 kilojoules of energy.
Though
slight, the advance is welcome news for the NIF scientists. In 2012, the
project was restructured and given more modest goals after six years of failure
to generate more energy than the experiment consumes, known as
"ignition".
Results
from the NIF facility will help scientists work out how to build a fusion
reactor, but the centre is funded primarily to help the US understand how its
stockpile of nuclear weapons is ageing. The experiments help to verify computer
models that are used in place of nuclear tests, which are now banned.
Omar
Hurricane, the lead author of the report, said the latest improvement came by
controlling the implosion of the spherical pellet more carefully. In previous
experiments, the pellet distorted as it was crushed, which seemed to reduce the
efficiency of the process. By squashing the fuel more softly, helium nuclei
that are produced in the fusion reactions dump their energy into the fuel,
heating it up even further, and driving a cycle of ever more fusion.
"We
are finally, by harnessing these reactions, getting more energy out of that
reaction than we put into the DT fuel," Hurricane said. The report appears
in the journal Nature.
The dream
of controlled fusion remains a distant hope, and Hurricane said it was too
early to say whether it was even possible with the NIF facility. The
researchers need to get a hundred times more energy from the fusion reactions
before the process can run itself, and more for it to deliver an overall
surplus of energy.
Steven
Cowley, director of the Culham Centre for Fusion Energy near Abingdon in the
UK, said the study was "truly excellent" and began to address the
core challenges of what is known as inertial fusion in the lab. He said the
team may need a bigger laser, or a redesigned capsule that can be squashed more
violently without becoming unstable. "Livermore should be given plenty of
time to develop a better capsule. It strikes me that we have only just begun to
understand the fusion regime," Cowley told the Guardian.
The Culham
lab has taken a different approach, called magnetic confinement. As long ago as
1997, the facility generated 16MW of power with 24MW put into the device.
"We have waited 60 years to get close to controlled fusion. We are now
close in both magnetic and inertial. We must keep at it. The engineering
milestone is when the whole plant produces more energy than it consumes,"
Cowley said.
The
experimental fusion reactor Iter, which is being built in France, is expected
to be the first plant to produce more energy than it consumes. The project has
faced delays of more than two years and overrun budgets, but is still an
international flagship for fusion research. "Iter is going slowly but
progress is happening," said Cowley.
Related Articles:
"Recalibration of Knowledge" – Jan 14, 2012 (Kryon channelled by Lee Carroll) - (Subjects: Channelling, God-Creator, Benevolent Design, New Energy, Shift of Human Consciousness, (Old) Souls, Reincarnation, Gaia, Old Energies (Africa,Terrorists, Cuba, Iran, North Korea, Venezuela ... ), Weather, Rejuvenation, Akash, Nicolas Tesla / Einstein, Cold Fusion, Magnetics, Lemuria, Atomic Structure (Electrons, Particles, Polarity, Self Balancing, Magnetism, Higgs Boson), Entanglement, "Life is necessary for a Universe to exist and not the other way around", DNA, Humans (Baby getting ready, First Breath, Stem Cells, Embryonic Stem Cells, Rejuvenation), Global Unity, ... etc.) - (Text Version)
“… The energy of your time is now appropriately ready for some of the theories that were before their time, which were just as accurate then as they are now. Watch for entirely new science to suddenly erupt with solutions for problems that you have been working on for years, solutions where you say, "Why didn't they think of that before?"
Expect cold fusion, by the way. I've told you this before. The experiment with cold fusion was accurate [speaking of the much-discounted Ponds and Fleshman experiment in the past]. The experimenters could not repeat their discovery because they were not aware of the attribute of magnetics that was influencing their experiment [which was done in a basement with the electric utility panels around them]. They thought it was simple chemistry. It wasn't. It was an accidental discovery of physics that remains a mystery at the moment, but that combines chemistry with magnetics, which few are trying. The same thing happened to Tesla, where he was actually able to observe an object fly off the bench, but really didn't know why. He knew it had to do with the design of magnetics, but couldn't begin to do the design with the tools and technology of the day. Can you imagine such a thing? Now you understand his depression. Such is the way advancement often happens on the planet. …”
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.