Boron Handling

[Giorgio]

A couple of interesting posts from Focusfusion about handling of Decaborane and the design of the related chamber:

http://focusfusion.org/index.php/site/a ... ng_issues/

http://focusfusion.org/index.php/site/a ... um_system/

[Aeronaut]

If I'm understanding it correctly, the apparent borane challenges are due to the single-shot test environment. Cooling system permitting, the ideal freq is quoted at ~1kHz to keep the fuel in gaseous form. The helium "ash" is automatically ejected as the ion beam headed for inductive conversion to an electrical pulse. Comments, please?

[IntLibber]

If I'm understanding it correctly, the apparent borane challenges are due to the single-shot test environment. Cooling system permitting, the ideal freq is quoted at ~1kHz to keep the fuel in gaseous form. The helium "ash" is automatically ejected as the ion beam headed for inductive conversion to an electrical pulse. Comments, please?

Boranes are notorious for leaving glassy deposits that are extremely resistant to high temperatures and difficult to remove, when combusted in rocket and turbine engines. Unless these guys get 100% conversion of all borane to helium, they are going to have accumulation of unfused boron compounds to deal with.

[KitemanSA]

Maybe that just adds to the neutron shielding.

[Nik]

Uh, I don't think the deposit thickness would have much impact on neutron flux, but it might provide a self-healing 'front surface' for the wall etc.

Like halogen lamps' halogen trace 'heals' hot-spots on the filament and removes spatter on the glass ??

( Within limits, of course, of course'

[KitemanSA]

Can you say "facetious"?

[hanelyp]

Boranes are notorious for leaving glassy deposits that are extremely resistant to high temperatures and difficult to remove, when combusted in rocket and turbine engines. ...

I expect reaction with oxygen is a major part of that process. In a polywell you might get straight boron or heavy boranes deposited. Good first wall if it doesn't get too heavy.

[D Tibbets]

I believe first wall issues are mostly irrelevant in a P-B11 Polywell (or DPF) as neutron production is relatively very low. The issues is if the elemental boron, or boron - hydrogen compounds deposited on surfaces modify the function (insulation issues) of those structures. Boron oxygen or boron nitride ceramics should not form in the machines as oxygen and nitrogen should be absent in the vacuum (the trace amounts might be an issue for longer lifetime mchines).

Dan Tibbets

[WizWom]

I believe first wall issues are mostly irrelevant in a P-B11 Polywell (or DPF) as neutron production is relatively very low. The issues is if the elemental boron, or boron - hydrogen compounds deposited on surfaces modify the function (insulation issues) of those structures. Boron oxygen or boron nitride ceramics should not form in the machines as oxygen and nitrogen should be absent in the vacuum (the trace amounts might be an issue for longer lifetime machine).

It would seem to me that if boride deposits form on the surfaces in a polywell, they should quickly vaporise in operation, and then could be balanced with appropriate injection of protons.

[Aeronaut]

Boron or borane deposits shouldn't be a problem on the chamber wall unless they significantly inhibit cooling.

But additional electrode resistance and or impedance will hurt, and either has the potential to make operation sporadic until the accumulations cripple it.

An automotive example is a spark plug fouling ever more until the car is undrivable.

[IntLibber]

There is actually an issue with formation of boron nitride compounds, these are the preponderance of the coking problem, whereas boron oxide is more commonly bauxite and will precipitate as an ash.

[Henning]

There's a post on focusfusion.org of a professor who is specialized in boron chemistry research:
http://focusfusion.org/index.php/forums ... /585/#6139

[Giorgio]

There's a post on focusfusion.org of a professor who is specialized in boron chemistry research:
http://focusfusion.org/index.php/forums ... /585/#6139

And this gentlemen, is a clear example of the power of Internet in helping solving experimental issues.
Good for Dr. Lerner. He choose to be open about results and issues he is facing and now he is getting the payback for his choice.

[ladajo]

sigh...
That is what it felt like when Rick was still posting...open science...
sigh...

[Torulf2]

This open research is superior. In combination with internet it can bring to gather knowledge that would be hard to do in the standard way of research. For secret project it may be impossible to get help from outside. The researchers may not even know there to ask.