Controlling Nuclear Fusion
Have you been able to control nuclear fusion yet?
We heard in science class that you cannot control it yet.
Check out the internet newsgroup sci.physics.plasma for regular
updates on the achievements in nuclear fusion. When you actually
look into it, "controlling nuclear fusion" actually involves
a bunch of steps. A group at Princeton has already achieved one
early step - they have a big magnetic container called a tokamak,
and they pump in some deuterium and heat it up to really high
temperatures (millions of degrees), and they have seen fusion to
the extent that they can actually measure the power output
(I think it was in the Megawatt range), which they can keep
going for at least a few seconds at a time. However, I do not think
they have achieved "ignition", which would be the point at which
the fusion energy is sufficient to sustain the high temperature
of the plasma and keep the fusion going. That means they have to
keep pumping power in. So, controlled fusion has been achieved,
but it is not very useful yet.
There is also another way of getting fusion which is to build
huge lasers and focus them in on tiny pellets of deuterium and
tritium, causing them to collapse and produce a very tiny
and extremely hot plasma, which can also produce fusion. However,
I do not think the laser groups have reached a high enough temperature
to actually enhance the fusion rate into a useful region (you can
always have fusions happening at random even below the extremely
high temperatures these experiments are trying to get to).
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Update: June 2012