D-T Snowballs in ITER Hell

DeltaV · Post by **DeltaV** » Thu Nov 03, 2011 5:58 pm

Fusion researchers see frozen pellet tech as way to control ITER's plasma as well as fuel it

D Tibbets · Post by **D Tibbets** » Sat Nov 05, 2011 1:34 am

Frozen pellets might be a good way to inject fuel, and it might help instabilities and it may dampen the plasma quickly. But I read this as cooling. If a substantial portion of the fuel is injected in this way the plasma will be cooled, not heated. Generally, I understand that fuel is injected as hot neutral plasma beams (neutral beam heating) This is a major part, if not the dominate means of heating the plasma. This is already a herculean effort. If they impede this mechanism, how else will they heat the plasma. Do they anticipate that improved microwave heating can take up the slack?

Dan Tibbets

rcain · Post by **rcain** » Sat Nov 05, 2011 4:06 am

interesting.

initially, i too thought it a little counterintuitive to be dumping frozen fuel in. but then i read:

....The researchers are also experimenting with pellets of neon and argon to control plasma events....

which seems to make more sense.

who knows, maybe they will eventually tame this beast and get some useful work out of it.

MSimon · Post by **MSimon** » Sat Nov 05, 2011 5:37 am

rcain wrote:interesting.

initially, i too thought it a little counterintuitive to be dumping frozen fuel in. but then i read:

....The researchers are also experimenting with pellets of neon and argon to control plasma events....
which seems to make more sense.

who knows, maybe they will eventually tame this beast and get some useful work out of it.

I don't know if you have been following ITER in the news, but with the economic implosion in Europe they are scrambling for funds. So far none have been allocated for the following year.

Here is one from June that lays out the basics:

http://www.euractiv.com/science/funding ... ews-495057

So far nothing has changed wrt funding.

Giorgio · Post by **Giorgio** » Sat Nov 05, 2011 6:49 am

Should be about time for them to reconsider this monstrosity and to divert those money on different research.

They could divert 10% of those founds to stellarator research like the Wendelstein.
A 10% to Alternate routes like Polywell and similar concepts.
A 10% on Surface Material, plasma heating and power exploitation.
A final 10% on basic research on magnets and superconductors.

The final 60% they simply save it and cut it from budget (we don't have the money anyhow).

Here you go, you have a multilevel and multidisciplinary research program with enough money to close any gap still left in the basics of engineering and building of a thermal machine based on a fusion concept.

Just a dream unfortunately, it would require for those EU bureaucrats to actually know what they are doing and how to best spend our money......

GIThruster · Post by **GIThruster** » Sat Nov 05, 2011 7:16 am

I remember reading about a frozen fuel pellet launcher about 25 years ago. The point then was that in the short time it takes the fuel to get inside the plasma, it had gone through phase change but that time was enough to get the fuel into the reaction. I can even remember the pellet launcher described as the size of a shoebox. Can't be the pellet machine itself that's news.

rcain · Post by **rcain** » Sat Nov 05, 2011 11:05 pm

MSimon wrote:I don't know if you have been following ITER in the news, but with the economic implosion in Europe they are scrambling for funds. So far none have been allocated for the following year. ...

yes, looks like they might be in trouble given the current world financial calamities.

more recent article here: http://www.europeanvoice.com/article/20 ... 71210.aspx

suggests they are considering making up some of the shortfall by diverting funds from the EU Common Agricultural Fund of all places. That and 'funding in kind'. As you say, 2012 onward, the books look empty so far.

i also think this project is already showing it is just too big to manage efficiently (as the LHC has similarly shown).

as Giorgio suggests, maybe now is a good time (ie. not yet too late) to put ITER on hold. But then again, i don't trust them not to squander any savings made some other how.

D Tibbets · Post by **D Tibbets** » Sun Nov 06, 2011 1:21 am

Concerning my previous post, I realize I might have been off base- at least partially. I was referring to the difficulty of heating the plasma to ignition conditions. Once that mode of operation is reached, I could see frozen fuel pellet injection viable as there would be excess energy from the fusion reactions to keep the plasma warm. In this situation the frozen pellets not only provide fuel but a knob to limit excessive heating/ runaway fusion.
Would this have any significance for increasing the run times for a near steady state condition?

Dan Tibbets