frog wrote:....(snip) Advanced Ceramics Research has done work for NASA in this area and may be a helpful resourse.
Well I hope my blather is somthing more than just taking up this space and time. What do you think? Anything to this?
What can you tell me about Advanced Ceramics Research? Their website doesn't go in much details about their ceramics, onlny their application of it.
or am I looking in the wrong direction? http://www.acrtucson.com/
Hello Frog,
The mechanical forces on the polywell MaGrid are considerable. Tesla fields confined next to each other require serious structural restraint or they will just fly apart.
At present, the MaGrid coils are supported on four standoffs, two to take current to the coils and two to provide some mechanical support. Some designs I have seen have four standoffs per coil, supported from the roof or walls or floor. The standoffs provide restraint as well as keeping the coils in alignment. The major stability of the MaGrid assembly at present is the six touchpoints which anchor each coil cover to its neighbour. These touchpoints represent a potential point of electron loss (a bad thing, which will prevent the polywell from reaching breakeven).
tonybarry wrote:At present, the MaGrid coils are supported on four standoffs...
...Some designs I have seen have four standoffs per coil, supported from the roof or walls or floor...
...These touchpoints represent a potential point of electron loss...
Tony, does this also mean that the standoffs are also points of electron loss?
Does this means that any means to suspend the coils is a certain way to lose electrons?
Isn't there a way to make the standoffs create their own magnetic field that will bend the coil's magnetic fields around them? This might decrease the chance of electrons hitting the standoff's (they might get stuck around them though).
If you want to tackle a project like this, ...
...From what i've been reading the necessary equipment to maintain a high vacum is very expensive, but i'm thinking it might be obtainable surplus.
Actually, the getting there I find fun and entertaining.
And the vacuum chamber part, wouldn't a university be willing to stick a test-ready contraption into a vacuum chamber for a decent price?
They bought the thing, and if it's doing nothing, it's actually eating money just by taking in space.
They probably would except for one thing. I suspect the electric feeds for the magnets and the electron gun, as well as the plumbing for the
cooling system for the magnets as well as the gas injector system, etc. are likely going to require a custom vacum chamber.
While it might be possible that a University has a vacum chamber of sufficient size with a sufficient number of suitable feed throughs,
that would be just TOO easy.
Of course that points up the first step. Check with your local University and see !
Another thought. Preparing the vacum chamber and the aparatus to operate might require a lot more exclusive time for their chamber than a University would be willing to provide. I dunno, but it's definitely well worth checking into.
Oh, and I don't think Universities really care about eating money.
Its current cost is less than copper for equivalent current carrying capacity.
And that is in low volume production. Once the production rates get up it will cost much less.
For our purposes it is an ideal material. You extract the B10 and use it as part of the shielding - plus a B11 only MgB SC should add another order of magnitude or more to dose toleration. It does require dropping the operating temp 1 or 2 deg K.
Yeah, I followed your links. If the company's projections are correct, they are talking $ 2.00 / Meter for 2008. Considering the price of copper nowadays, MgB2 is getting more competitive every year !
I think operating at 1 or 2 deg K makes things a lot tougher. Hopefully something that works at liquid nitrogen temperatures can be developed.
vernes wrote:Isn't there a way to make the standoffs create their own magnetic field that will bend the coil's magnetic fields around them? This might decrease the chance of electrons hitting the standoff's (they might get stuck around them though).
I believe so. To repost an idea from the magrid brainstorming thread: viewtopic.php?t=289&start=0
Have the outer sections of the coils outside the negative grid. Or case the magnets in an insulator and charge up only the inner section. Other potential configurations may exist.
Vernes wrote:Tony, does this also mean that the standoffs are also points of electron loss?
Does this means that any means to suspend the coils is a certain way to lose electrons?
Isn't there a way to make the standoffs create their own magnetic field that will bend the coil's magnetic fields around them? This might decrease the chance of electrons hitting the standoff's (they might get stuck around them though).
Hello Vernes,
Standoffs tend to be made of a conductive centre shaft with a ceramic layer around them, like a power pole insulator.
My limited understanding is that the standoffs are a second-order loss mechanism, because they exist on the "other" side of the polywell. The outside of the standoff will accumulate a static surface charge of itself because it's an insulator. I believe once this surface charge has accumulated, losses into the standoff itself reduce to a minimum.
tonybarry wrote:(snip)...I believe once this surface charge has accumulated, losses into the standoff itself reduce to a minimum.
Thank you, I understand now.
This also means that it is quite possible to give each coil it's own standoffs (from walls, ceiling) and remove the connection between coils.
...
But does that also mean the outer surface of the coils are also building up this surface charge? I mean, with the standard polywell design, the material connecting the coils to eachother also gets hit by electrons, this charge would be shared with the coils, correct?
Sorry if this is something obvious, I'm not quite that experienced with the subject.
Any electrons hitting the grid surface will be replaced by the power supplies(positive). Alpha particles hitting the surface will reduce power supply requirements.
The grids are made of metal so charges will flow in them and distribute according to the electric field.
Engineering is the art of making what you want from what you can get at a profit.
