FUSION MUSINGS

IWhile this is certainly Earth-bound, its implications are far reaching! Space fusion based travel to the Earth to another Earth…..and on and on…

Did you know that MIT had a Plasma Science and Fusion Center? Neither did I. They are doing exciting experiments into the world of Fusion. Fusion is based off of something we all understand, the Sun. Nuclear fusion is a process that makes one singular heavy nucleus from two lighter nuclei. In this process it releases a considerable amount of energy (the mass of the nucleus is not as heavy as the two nuclei as the loss mass represents the energy released. Sound familiar? E=MC2)

You are in the middle of the Sun or some random star. You see all sorts of atoms around you. Not all of these atoms can be joined – heavier elements have a harder time than lighter one. Lighter ones such as Hydrogen atoms that fuse together to make Helium (& energy is released.) To go off topic a tad – when everything in a star that can, has fused often what is left cannot be fused, it is too heavy of an atom. Most likely it is iron. The iron nucleus cannot fuse with other nuclei. At this point the reactions die and so does the star. But we’re not in a star. But we are creating the same reaction all in order to obtain the energy released.

When you hear about nuclear often what is thought about is not good. Because what you hear about most likely is Fission. Nuclear fission is the reverse. It is the heavy nucleus being bombarded, splitting into two smaller nuclei and a heap of energy but also a heap of what we now know as nuclear waste. Because we are not a star, it is rather difficult to cause a nuclear reaction; at least a fusion reaction. Any success to date on a regular basis has been in weaponry. Nuclear fission may be easier, but it is neither safe nor clean (fusion is both.)

One of the concerns was how to hold on to a star. Not literally, but the hot plasma which is ten times hotter than the Sun must be contained while the energy is collected. A line must be walked between too big that the plasma is unable to heat up enough and too small and impurities are allowed to press up against the walls of the container, building up inside the hydrogen plasma and preventing reaching a steady state basically impossible.

Up until now what has been used in the attempt to broker the balance is something called the tokamakA – but don’t bother memorizing its name. The Shoelace Antennae is the one you want to know. Developed by MIT as an enhancer that drives the short wavelength fluctuations at the plasma boundary; the new antennae is used in conjunction with and not to replace the tokamak as their jobs are different.

Odd as it might sound, the controlled shaking at the plasma edge seems to provide the desired event of regulating heat and particle flows. This was managed previously through tuning the controls of the tokomak: Taking over from the turbulence and fixing outflows to favorable levels while suppressing violent bursts of heat & plasma but requiring fine tuning, always fine tuning.

 

Under the right conditions, special resonant vibrations appear naturally at the plasma edge. They take over from the turbulence, and often fix outflows at more favorable levels while suppressing violent bursts of heat and plasma. At present, the standard way to call up these edge fluctuations is to tune the control parameters of the tokamak until they turn on spontaneously.

According to MIT this is still a work in progress, but most of us don’t have works in progress that will change the world!