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Laser fusion trio team up to
develop clean power
There's a big new kid on the nuclear energy block. Last week British firm
AWE (formerly the Atomic Weapons Establishment), based in Aldermaston,
the Rutherford Appleton Laboratory in Harwell, UK, and the Lawrence
Livermore National Laboratory in California said they would team up to
develop laser fusion as a clean energy source.
Laser fusion is an alternative to magnetically induced nuclear fusion, which
is used in the Joint European Torus (JET) now operating in Culham, UK, and
the test reactor ITER, under construction in Cadarache, France.
Historically, laser fusion has been used focused mostly for weapons
testing, while power generation research has concentrated on magnetic
fusion. Is that about to change? New Scientist has the answers.
What is laser fusion?
At high temperatures and pressures, the nuclei of the heavy hydrogen
isotopes deuterium and tritium form a plasma and can be fused to form
helium, releasing energy and a neutron. Firing a synchronised barrage of
laser pulses
can vaporise the surface of a pellet filled with these
isotopes, forcing the pellet to implode and so producing fusion conditions
inside the pellet for a few billionths of a second.
The physics resembles the detonation of a thermonuclear (or hydrogen)
bomb – although on a much smaller scale – and so the US has used laser
fusion to simulate these explosions.
What advantages does it have over magnetic fusion?
Magnetic fusion reactors zap heavy hydrogen gas with a powerful electrical
pulse to produce a plasma. A strong magnetic field is then required to
confine the plasma before fusion can take place. That's hard, because
plasmas can quickly leak or become unstable. By contrast, laser fusion
produces much higher temperature and pressures, so fusion occurs faster,
and the plasma must be confined for only billionths of a second.
Fusion of either kind is attractive as a power source because the fuel is
more abundant than uranium, and the process does not produce the highly
radioactive isotopes generated by splitting uranium atoms.
What stage is the tech at, and who is working on it?
Laser fusion has been studied since the 1960s, with most US funding
coming from the nuclear weapons programme. Today's biggest fusion laser
is the National Ignition Facility (NIF) at Livermore. By the end of next year,
Livermore hopes to reach "ignition" by producing more energy from fusion
than is needed to generate the laser pulse.
Smaller lasers are used in fusion programmes at Rutherford Appleton, the
University of Rochester in New York and Osaka University, Japan; France is
building a NIF-sized system called Megajoule Laser. ITER, meanwhile, is
adecade from igniting magnetic fusion.
When will laser fusion come to the power grid?
Livermore's Mike Dunne says that if all goes well, a plant delivering about
440 megawatts of electricity could be up and running in a decade;
full-scale versions that follow would deliver about 1000 megawatts.
But don't hold your breath. "So far this is at the border of science fiction,"
says Hans Kristensen, director of the nuclear information project of the
Federation of American Scientists. "The technological hurdles are not
nearly explored yet."
Is there anything I need to worry about?
Laser fusion reactors will not have a large volume of hot material that
might melt down if power failed, as occurred at the Fukushima Daiichi plant
in Japan earlier this year. But fusion neutrons are hazardous and will make
other materials in the reactor radioactive. The tritium in the fuel is also
radioactive: it emits beta particles so is dangerous if inhaled and has a
half-life of 12.5 years.
Laser fusion trio team up to develop clean power - tech - 13 September 2011 - New Scientist
This video explains it really well: Video - Laser fusion - New Scientist
develop clean power
There's a big new kid on the nuclear energy block. Last week British firm
AWE (formerly the Atomic Weapons Establishment), based in Aldermaston,
the Rutherford Appleton Laboratory in Harwell, UK, and the Lawrence
Livermore National Laboratory in California said they would team up to
develop laser fusion as a clean energy source.
Laser fusion is an alternative to magnetically induced nuclear fusion, which
is used in the Joint European Torus (JET) now operating in Culham, UK, and
the test reactor ITER, under construction in Cadarache, France.
Historically, laser fusion has been used focused mostly for weapons
testing, while power generation research has concentrated on magnetic
fusion. Is that about to change? New Scientist has the answers.
What is laser fusion?
At high temperatures and pressures, the nuclei of the heavy hydrogen
isotopes deuterium and tritium form a plasma and can be fused to form
helium, releasing energy and a neutron. Firing a synchronised barrage of
laser pulses
can vaporise the surface of a pellet filled with theseisotopes, forcing the pellet to implode and so producing fusion conditions
inside the pellet for a few billionths of a second.
The physics resembles the detonation of a thermonuclear (or hydrogen)
bomb – although on a much smaller scale – and so the US has used laser
fusion to simulate these explosions.
What advantages does it have over magnetic fusion?
Magnetic fusion reactors zap heavy hydrogen gas with a powerful electrical
pulse to produce a plasma. A strong magnetic field is then required to
confine the plasma before fusion can take place. That's hard, because
plasmas can quickly leak or become unstable. By contrast, laser fusion
produces much higher temperature and pressures, so fusion occurs faster,
and the plasma must be confined for only billionths of a second.
Fusion of either kind is attractive as a power source because the fuel is
more abundant than uranium, and the process does not produce the highly
radioactive isotopes generated by splitting uranium atoms.
What stage is the tech at, and who is working on it?
Laser fusion has been studied since the 1960s, with most US funding
coming from the nuclear weapons programme. Today's biggest fusion laser
is the National Ignition Facility (NIF) at Livermore. By the end of next year,
Livermore hopes to reach "ignition" by producing more energy from fusion
than is needed to generate the laser pulse.
Smaller lasers are used in fusion programmes at Rutherford Appleton, the
University of Rochester in New York and Osaka University, Japan; France is
building a NIF-sized system called Megajoule Laser. ITER, meanwhile, is
adecade from igniting magnetic fusion.
When will laser fusion come to the power grid?
Livermore's Mike Dunne says that if all goes well, a plant delivering about
440 megawatts of electricity could be up and running in a decade;
full-scale versions that follow would deliver about 1000 megawatts.
But don't hold your breath. "So far this is at the border of science fiction,"
says Hans Kristensen, director of the nuclear information project of the
Federation of American Scientists. "The technological hurdles are not
nearly explored yet."
Is there anything I need to worry about?
Laser fusion reactors will not have a large volume of hot material that
might melt down if power failed, as occurred at the Fukushima Daiichi plant
in Japan earlier this year. But fusion neutrons are hazardous and will make
other materials in the reactor radioactive. The tritium in the fuel is also
radioactive: it emits beta particles so is dangerous if inhaled and has a
half-life of 12.5 years.
Laser fusion trio team up to develop clean power - tech - 13 September 2011 - New Scientist
This video explains it really well: Video - Laser fusion - New Scientist