Reply To: Global Warming

[zapkitty]

Earl of Plasma wrote: I’m trying my best to understand this process of fusion so I have some Questions.

Welcome to the Focus Fusion Society forums!

Earl of Plasma wrote: “First temperature. PPL are talking about several hundred milj kelvin acheaved in experiments. Other have problems to reach even 100 milj Kelvin. Just with electrodes as it seems? For exemple a Tokamak use current and radio waves just to reach 100 milj degrees. How is that possibly? How do they do?

Size is the key… or lack of it 🙂

LPP (Lawrenceville Plasma Physics) achieved the confinement of ions with energies in excess of 100 keV (100,000 electron volts) which is the equivalent of a temperature of over 1 billion degrees Celsius. They did this in a device called a dense plasma focus… and the plasmoid where this occurred was only a few hundred microns across and lasted only for a few microseconds.

But that was enough to achieve the desired temperatures and confinement times for boron-hydrogen fusion and that’s what matters. Now LPP is working on increasing the density of their plasmoids.

ITER, on the other hand… well, although ITER only needs to reach a temperature of 100 million degrees to fuse its deuterium-tritium fuel its tokamak design has to try to heat a volume of plasma of 840 cubic meters to that temperature for about 300-500 seconds at a time… and that’s proven to be quite a challenge for them.

Earl of Plasma wrote: Magnetic field. PPL are talking about giga Gauss in the magnetic field of the plasma. 1 giga Gauss is about 100 000 Tesla. 100 Tesla is pretty much and is hard to achieve for long time. How is that possibly?

Same way the temperatures are achieved: in a very small space for a very short time.

Rather than trying to fight the natural instabilities of the process the Focus Fusion design takes advantage of them and lets them run their course.

And LPP and Focus Fusion advocates are not the only ones to have noticed that smaller and faster might be a better route to fusion. Indeed, quite a few alternative non-tokamak fusion designs are now under development and are seeking funding.

And yet President Obama’s new budget proposal once again cuts domestic fusion research funding and transfers it to ITER…