Electrode Degradation Solution?

[Phil’s Dad]

Sorry – not spel cheked.

[Brian H]

Phil’s Dad wrote: Hmm 🙂 You really would need to produce a heck of a lot more energy to produce a thermal inbalance given the amount we get from the sun. Especialy given the low relative heat output of fusion energy. In fact the amount of heat at the surface is less relevant than how long it sticks around. I wonder if we are not just saying “Let it go”. It seems counter intuative right now because of the prsoius nature of current energy supplies, but all that is about to change. :cheese:

Sorry – not spel cheked

Kwite orrite. Just done dune it agin!
😛

Now that I think of it, even nuclear heat isn’t a new thing for the planet. The reason the Earth’s core is still molten, and not cooled and hardened, is radioactive warming. We’re standing on a big, slow reactor! :bug:

P.S. What DID you mean by “prsoius”? Precious? Porous? Precarious? Pertinacious? I can’t come up with a good guess, and it’s moggling my bind!

[Aeronaut]

texaslabrat wrote:

Indeed…however if the predictions on the ultra-low cost per unit and per kWh hold true…you can bet that there will be millions of them built and then much more overall waste heat will be produced as we consume orders of magnitude more power in our society due to the near-free cost of it 😉 That old supply-and-demand curve thing.

No one would ever need more than a megawatt.

Just as no one would ever need more than 640K bytes of memory in their computer.

-Dave

ROFL absolutely!

How’s this scenario- 20 years from now, (if that) when the X-ray converter engineering is cut-and-dry, and ever smaller, lighter packaging become THE competitive advantages for FF factories, the electric air car will become the new Model T. Imagine at least one FF in every garage or back yard…

[Phil’s Dad]

Brian H;

“P.S. What DID you mean by “prsoius”? Precious? Porous? Precarious? Pertinacious? I can’t come up with a good guess, and it’s moggling my bind!”

What has it got in its pockets my…

(Your first guess)

[Rezwan]

Phil’s Dad wrote: Sorry – not spel cheked.

Some basic tips on forums: While you can’t edit other people’s posts, you should be able to edit your own, even after you’ve posted.

The button is right there on your own posts, on the same line with “quote”. Also, I think you can delete your own posts. Handy, if you want to hide the evidence. Although what you write’s been cached somewhere, and if someone’s quoted you, there’s no deleting it anymore.

OK. Now to go back and figure out where to cut this post and start the new thread.

[Rezwan]

jamesr wrote: I’m fully aware of what DPF & ITER are. As Brian said, I was trying to suggest that although some may regard the large scale & expensive tokamak projects as ‘the enemy’, there is a lot of valuable research going on in that field to do with materials properties and the interactions of plasmas with solid interfacing components.

Some of this may be applicable to the plasma/solid boundaries in a DPF. We need to take advantage of all the modelling and experimental results they get.

I should disclose my interest – I have just finished a Masters in nuclear physics, and will be starting a PhD in a few weeks modelling edge turbulence and instabilities in tokamaks and stellarators. Initially using data from the Mega Amp Spherical Tokamak (MAST) at Culham, UK and the Large Helical Device (LHD) in Japan.

Although my research may be from the mainstream side (I needed funding), I hope to be able to apply it different scenarios like focus fusion.

James

Hello! Just split the “earth’s core” debate off of this post. It seems to me like the rest of this is still about electrodes. Although I can take the quote above and start another thread on “My “enemy” is no longer my enemy when I’m taking advantage of their modeling and experimental results” – or “Blasting the boundaries of different experimental approaches: Learning from our esteemed colleagues and the Tokamak”…

Congratulations on your Masters, James!

[Henning]

Boron actually is one of the hardest materials. Ok, hardness might be not the only thing to prevent electrode degradation.

In some configurations it even outperforms diamond:
http://www.newscientist.com/article/mg20327241.200-diamonds-are-for-softies–boron-is-harder.html?full=true&print=true

As pure boron (B28), which is half as hard as diamond (see above), it looks like this:
http://www.ethlife.ethz.ch/archive_articles/090129_Oganov_Bor/index_EN

Might be still hard to produce anyway.

[JimmyT]

Aeronaut wrote:

Indeed…however if the predictions on the ultra-low cost per unit and per kWh hold true…you can bet that there will be millions of them built and then much more overall waste heat will be produced as we consume orders of magnitude more power in our society due to the near-free cost of it 😉 That old supply-and-demand curve thing.

No one would ever need more than a megawatt.

Just as no one would ever need more than 640K bytes of memory in their computer.

-Dave

ROFL absolutely!

How’s this scenario- 20 years from now, (if that) when the X-ray converter engineering is cut-and-dry, and ever smaller, lighter packaging become THE competitive advantages for FF factories, the electric air car will become the new Model T. Imagine at least one FF in every garage or back yard…

Yes and I can see implementation of the Moller-skycar finally becoming a reality. And people will still be talking on their cell phones while driving/flying and applying their make-up. Only instead of having a fender bender as a result, they will come crashing thru your roof.

[Aeronaut]

JimmyT wrote:

Indeed…however if the predictions on the ultra-low cost per unit and per kWh hold true…you can bet that there will be millions of them built and then much more overall waste heat will be produced as we consume orders of magnitude more power in our society due to the near-free cost of it 😉 That old supply-and-demand curve thing.

No one would ever need more than a megawatt.

Just as no one would ever need more than 640K bytes of memory in their computer.

-Dave

ROFL absolutely!

How’s this scenario- 20 years from now, (if that) when the X-ray converter engineering is cut-and-dry, and ever smaller, lighter packaging become THE competitive advantages for FF factories, the electric air car will become the new Model T. Imagine at least one FF in every garage or back yard…

Yes and I can see implementation of the Moller-skycar finally becoming a reality. And people will still be talking on their cell phones while driving/flying and applying their make-up. Only instead of having a fender bender as a result, they will come crashing thru your roof.
Yep, much like Moller. Except there’s a new pilot’s license classification and air traffic control infrastructure in the works where we’ll fly like airliners- on autopilot, with the autopilot being coached from the ATC computers. Government’s not as dumb as it may appear at times, lol.

[Tasmodevil44]

I don’t know if a rotating insulator would work. Especially when considering the short few picoseconds it all has to take place. Interesting concept, though. But never give – up thinking outside the usual paradign of thought. Sooner or later, one of these hair – brained ideas will strike the pot of gold at the end of the rainbow…… er, ah……. plasmoid ! ! ! 🙂

[Brian H]

Henning wrote: Boron actually is one of the hardest materials. Ok, hardness might be not the only thing to prevent electrode degradation.

In some configurations it even outperforms diamond:
http://www.newscientist.com/article/mg20327241.200-diamonds-are-for-softies–boron-is-harder.html?full=true&print=true

As pure boron (B28), which is half as hard as diamond (see above), it looks like this:
http://www.ethlife.ethz.ch/archive_articles/090129_Oganov_Bor/index_EN

Might be still hard to produce anyway.

You threw me a bit with that. B28? That would be, let’s see, 5 protons and 23 neutrons? Nah. But a crystal of 28 boron atoms: that’s quite a rig! On the downside, making boron a machine-tool resource would make it more valuable/costly. Oh, well.

[Henning]

Brian H wrote:
You threw me a bit with that. B28? That would be, let’s see, 5 protons and 23 neutrons? Nah. But a crystal of 28 boron atoms: that’s quite a rig!

Did it on purpose. 😉

[Brian H]

Aeronaut wrote:
…
a new pilot’s license classification and air traffic control infrastructure in the works where we’ll fly like airliners- on autopilot, with the autopilot being coached from the ATC computers. Government’s not as dumb as it may appear at times, lol.

Yes it is; just wait till the first exploits appear on the web to take over the autopilots or the ATC relics and organize big Mosh-Pits in the Sky over downtown Metropolis!

[vansig]

Getting seriously down to the topic of electrode erosion, here…
if i remember correctly, as of today it’s measured in the microns per pinch. Obviously this wont do for production. But the electrodes in use, today, are copper, rather than beryllium, which absorbs more xrays.
Are they also not as aggressively cooled as planned?

Cu
m.p. = 1357.77 K
heat capacity = 24.440 J·mol−1·K−1
thermal conductivity = 401 W·m−1·K−1
electrical resistivity = 16.78 nΩ·m

Be
m.p. = 1560 K
heat capacity = 16.443 J·mol−1·K−1
thermal conductivity = 200 W·m−1·K−1
electrical resistivity = 36 nΩ·m

What’s gained in higher melting point by using beryllium could be lost via increased electrical resistance, lower heat capacity, and lower thermal conductivity. On the other hand, with pulse timing in nanoseconds, the skin effect comes into play, as well. The beryllium should have a deeper skin depth (~9..90 μm through the pulse, as opposed to ~6..60 μm for copper).

Even so, unless a thin coating of something like tantalum-hafnium-carbide (m.p. 4488 K) can totally eliminate erosion, i’m not seeing an easy way to keep down xray absorption. Will it?

[Author]

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