Talk-Polywell.org

I did a search and the term aerogel hasn't come up once. I know they're a bit hydroscopic, but there isn't any water involved, and they have some amazing thermal properties. give them a diamond coating and call it a day?

I presume you mean this as the protection scheme for superconductive MAGrids under the alpha bombardment? If so, perhaps it is time to railroad, because I have been looking at diamond as a good coating myself. Especially now that CVD methods have been improved so much.

There doesn't SEEM to be much effect on diamond, even under 40Mev alpha bombardment, except to change the color. the few studies I have been able to read don't suggest any deleterious effect on the structure of the material, not mentioning "sputtering" loss at all. Of course, I am pretty sure that the experiments weren't set up to detect minor effects, just the color change they were looking for.

Needs more work.

KitemanSA wrote:I presume you mean this as the protection scheme for superconductive MAGrids under the alpha bombardment? If so, perhaps it is time to railroad, because I have been looking at diamond as a good coating myself. Especially now that CVD methods have been improved so much.

There doesn't SEEM to be much effect on diamond, even under 40Mev alpha bombardment, except to change the color. the few studies I have been able to read don't suggest any deleterious effect on the structure of the material, not mentioning "sputtering" loss at all. Of course, I am pretty sure that the experiments weren't set up to detect minor effects, just the color change they were looking for.

Needs more work.

The high end for chemical bonds is around 15 eV. Even assuming a lattice effect of 10X that you are only up to 150 eV. The alphas will be coming in at about 2 MeV. Lots of sputtering.

If you are running a pB11 reactor the best thing is to have a Boron11 coating. No poisoning of the reaction. Sputtering just feeds in fuel.

MSimon wrote: If you are running a pB11 reactor the best thing is to have a Boron11 coating. No poisoning of the reaction. Sputtering just feeds in fuel.

This question has came up and been answered several times on various threads now and no one has countered it effectively so I believe you.
But, I have a question.

Is there any chance that sputtered Boron11 will flood the reactor with to much fuel? There are 3 alphas per reaction, 10 - 20 percent of them will impact Boron11 coating. How much B11 fuel will be sputtered off for each impact, I wonder?

Aero wrote:

MSimon wrote: If you are running a pB11 reactor the best thing is to have a Boron11 coating. No poisoning of the reaction. Sputtering just feeds in fuel.

This question has came up and been answered several times on various threads now and no one has countered it effectively so I believe you.
But, I have a question.

Is there any chance that sputtered Boron11 will flood the reactor with to much fuel? There are 3 alphas per reaction, 10 - 20 percent of them will impact Boron11 coating. How much B11 fuel will be sputtered off for each impact, I wonder?

Good question. So far there is no definitive answer. One gain is that the coils only get hit with 20% of the alphas. So there is a factor of 5X gain right there. Will it be enough? Stay tuned.

MSimon wrote:

Aero wrote:

MSimon wrote: If you are running a pB11 reactor the best thing is to have a Boron11 coating. No poisoning of the reaction. Sputtering just feeds in fuel.

This question has came up and been answered several times on various threads now and no one has countered it effectively so I believe you.
But, I have a question.

Is there any chance that sputtered Boron11 will flood the reactor with to much fuel? There are 3 alphas per reaction, 10 - 20 percent of them will impact Boron11 coating. How much B11 fuel will be sputtered off for each impact, I wonder?

Good question. So far there is no definitive answer. One gain is that the coils only get hit with 20% of the alphas. So there is a factor of 5X gain right there. Will it be enough? Stay tuned.

Unfortunately, I calculate it differently - 5 fusions is 15 alphas with 20% potentially resulting in sputter events, so I calculate only 1.7X gain. Do some of the impacts ricochet and not sputter? Do some of them sputter more than one B11? If so the answer may possibly be found in the geometry of the Magrid shielding.

Yes, I will stay tuned...

so aerogel coated in boron, doesn't change the fact that as far as insulation goes aerogel is hard to beat.

Professor Science wrote:so aerogel coated in boron, doesn't change the fact that as far as insulation goes aerogel is hard to beat.

Vacuum is better.

A quick googling found these specificationsfor a specific flavor of aerogel. Wikipedia mentions the most insulative aerogel is silica based with added carbon, but apparently lacks a citation, so take that with the obvious grain of salt.

MSimon wrote:

Professor Science wrote:so aerogel coated in boron, doesn't change the fact that as far as insulation goes aerogel is hard to beat.

Vacuum is better.

I recall reading that natures abhors vacuums, resulting in perpetual need for pumping to get even a reasonable vacuum. Aerogel would have the perk of stability wouldn't it?

MSimon wrote:The high end for chemical bonds is around 15 eV. Even assuming a lattice effect of 10X that you are only up to 150 eV. The alphas will be coming in at about 2 MeV. Lots of sputtering.

So what we have is an assessment that it SHOULD sputter, and many years of cyclotron modified diamond at 20 - 40 MeV without obvious mention of it. Hmm. Perhaps we need to actually get an ACTUAL study / experiment done to settle this.

I would put in some substantial $$.