Nuclear Fusion

[WeAreBongo]

Just how close is mankind to successfully harnessing the energy potential of nuclear fusion? Will fossil fuels be rendered obsolete in the next hundred years? I believe there's an experiment about to be conducted that hopes to safely generate more energy than it took to initiate the reaction. Anyone know the official website? Cheers!

[beso]

We have been depending on fusion energy since our ancestor was a primitive cell. Apparently we can only enjoy this situation for about another about 4 Billion yrears.

[jake-the-peg]

There was a bit of a false start with nuclear fusion about 40 years ago that resulted in a common mis-aprehension that we are "always 40 years away"

There are a number of different methods under investigation.

The biggest and furthest advanced is the Tokamak - a kind of magnetic bottle that holds the plasma in a torus ("donut").

JET was a tokamak that was built in Culham, just south of Oxford as a European project. Jet achieved fusion but wasn't designed to produce more energy than it took to run. IE didn't reach breakeven.

Currently the next stage machine ITER ( http://www.iter.org ) is being built in Cardache in France. It will achieve
breakeven but it's still an experiment, it won't produce electricity. DEMO will follow and be the first electricity
generating system - probably in Japan - and that'll probably be around 2030.

There are other routes to fusion such as the Z-pinch or laser systems. It was one of these that reached a milestone this week.

The US National Ignition Facility was ready this week http://news.bbc.co.uk/1/hi/sci/tech/7972865.st m

This is a massive laser system but they've still got quite a lot of work to do too.

There was quite a good Horizon program recently with Brian Cox going over the current state of progress on Fusion.

Not sure if it's still on iplayer but you can see it on youTube https://www.youtube.com/watch?v=UNsEi1yL3jQ&fea ture=related

In the long run we have to get Fusion to work. Renewables are good but they can't sustain the planet's needs.

The question is whether we can do it before we run out

[Clanad]

Funny you should mention that... Seems Cold Fusion possibilities are back in the news. The significance of the latest lab tests is being hotly (no pun intended) debated even as we speak... read here:

http://news.yahoo.com/s/afp/20090324/ts_alt_af p/usscienceenergynuclear

[jake-the-peg]

Ah I forgot Cold fusion.

This started off as pretty much a bad joke, the idea that you could somehow get fusion to happen at room temperature by just passing an electric current through a special metal.

Well really a bunch of snake-oil. But there is one slightly interesting arm to come from that, what is known as muon catalised fusion.

Unlike the original cold-fusion ideas there is a real credible model for getting this to work. the drawback is that you need a lot of muons which are subatomic particles with a very short half life, mostly formed in collisions.

I wouldn't rule out MCF but it's a bit of an outside bet at the moment.

The US Navy group that Clanad's link refers to have been hailing triumphs for years:

http://www.dailytech.com/article.aspx?newsid=7 168 in 2007

http://video.google.com/videoplay?docid=-28439 14499166355574
2005

http://www.lenr-canr.org/Collections/USNavy.ht m 2003

Actuallly seems every 2 years (wonder if they're funded biannually)

Normally it shows some events like some neutron tracks that researchers claim is proof of cold fusion and either turns out to be from something else or nobody can reproduce it.

I wouldn't bet the farm on them running your car any time soon!

[beso]

There is a type of cold fusion that really does work. Its was developed in the late 1940s and its pioneers won a Nobel Prize.

It uses a short lived negatively charged particle called a muon that behaves like an electron except being much heavier it orbits much close to the nucleus.

Deuterium atoms bound together in a chemical reaction where the covalent electrons are replaced by muons pulls the nucleui close enough together to fuse and the muon is released. One muon can catalyse a few hundred reactons in its short life.

The process literally works at room temperature but its optimum temperature is about 700 degrees C which is precisely the temeperature used in steam turbines.

Unfortunately the energy required to make muons exceeds the fusion output by a factor of three. If muons could be produced more efficiently then cold fusion would become practical virtually overnight.

http://en.wikipedia.org/wiki/Muon-catalyzed_fu sion

[WeAreBongo]

Thanks folks, there's plenty of reading material to keep me occupied during work there! Cheers.