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Let's do some fusion!

Nuclear fusion... it's the clean, green energy source of the future.

Or so we have been told for many decades now.

In theory, fusion is really simple stuff. Just get one element, strip the electrons from the protons (and neutrons if any) into a atomic soup called "plasma" then apply lots of pressure so as to force them to recombine in the form of a new element or elements whilst at the same time releasing huge amounts of energy.

So what are we going to need?

A some hydrogen, a Bic lighter, a hammer and some safety glasses -- right?

Well unfortunately it's not quite that easy -- as scientists who have been working on the problem for many decades, keep rediscovering.

Several different concepts for fusion reactors have been mooted and even built over the years and most of them have worked.

Creating plasma is a piece of cake. Just heat up your "stuff" until it gets so hot that, at an atomic level, it flies apart into its constituent components. Sadly, a Bic lighter doesn't come close to generating the necessary temperatures so it becomes necessary to use electrical or light energy to create plasma.

But then comes the really hard part.

Convincing this soup of atom-bits to re-assemble into new, denser elements (with spare bits left over that get turned into energy) is not so trivial. That's because the nuclei of the atoms are all positively charged and will thus repel each other very strongly. What's more, they're free to move around so if you try to hit them with your hammer, they'll just move out of the way.

Perhaps the best analogy is like trying to make diamonds by smacking powdered carbon with your fist. We know it takes heat and pressure to turn carbon into diamond but your fist and a Bic lighter fall well short of the mark -- so it is with nuclear fusion.

What's required to do this is enormous overall pressure. Basically we've got to confine then squeeze these bits so much that they are literally *forced* together and that's hard. Really, really hard!

Several strategies have been tried so far and they include:

Inertial confinement...

This method works by creating the plasma and its containment vessel so quickly that its pressure peaks to massive levels simply because it can't get out of its own way quickly enough as it tries to expand. To date, this has been done by taking tiny glass beads filled with deuterium and tritium (isotopes of hydrogen) and blasting them with an incredibly short but powerful laser pulse.

The problem with this form of fusion is that we still can't get enough energy out of the fusion to make it viable. That laser pulse usually involves petawatts of energy and, although some fusion is created, the energy returned still falls short of any useful amount because of the small quantities of material being fused.

The next strategy is magnetic confinement...

In order that larger amounts of material can be fused, and thus greater energy generated, magnetic confinement has been attempted.

In this case, the hydrogen isotopes are converted into a plasma (usually by a powerful electrical current passing through them) and attempts are made to "squeeze" the plasma cloud using a magnetic field.

This might sound pretty simple -- until you realise that it's somewhat akin to trying to juggle jelly. The plasma cloud is a seething writhing mass and when the magnetic field squeezes on it, there is a tendency for it to squirt out through any area of inconsistency or weakness in that field. To date, even the most sophisticated forms of magnetic containment have been unable to sustain any form of fusion reaction long enough to provide practical levels of energy generation.

Then, of course, there is "cold fusion"...

Although there was a burst of interest in the prospect of CF some years ago when P&F claimed to have achieved such, this has been widely debunked as bad science. However, there is still no guarantee that some form of CF might not be possible -- perhaps using a catalyst such as palladium or nickel to fuse the nuclei of certain elements into new ones... releasing excess energy in the process. The most dangerous thing to science is a closed mind!

So why have I blathered on about this subject today?

Well I mentioned a few columns ago that I was going to embark in a somewhat new direction -- my ability to earn a living from my RC model videos now having effectively been taken from me by the actions of grumpy old men at MFNZ and the new diktats from CAA. I won't be giving up making YouTube videos though and I figure that perhaps I'll focus on some creating some outrageous DIY science projects.

The first of these will be a DIY nuclear fusion reactor.

No, I'm not kidding. The reality is that building a fusion reactor is not at all beyond the abilities of anyone with some basic tools and understanding of what's involved.

The catch however, is that such a reactor will produce only *minuscule* levels of energy -- many orders of magnitude less than the energy that is input. Fusion is easy -- sustainable over-unity fusion is still impossible, based on the technology we've used to date. So far the largest fusion reactions created by mankind have been in the form of H-bombs and I don't think we'll be doing that in the shed out back.

However, I will show folk how to create the atomic soup that is plasma and how to check if some form of fusion is occurring -- even at very, very low levels.

One of the first videos will also show how to use nuclear fusion to disintegrate common household products. Yes, I *will* be building a nuclear fusion powered "destructor-ray" for $4. A device that can melt metal, incinerate most substances and destroy almost anything you place before it -- no, I am *not* kidding (but think about it a little).

In order to make the money necessary for survival, I have to create videos that have a broad appeal -- this means "sizzle" as well as steak. Through these videos I hope to educate, inform and most definitely -- entertain.

Stay tuned, I hope you'll like it!

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