Selective ion-cyclotron resonance ...

Discuss the technical details of an "open source" community-driven design of a polywell reactor.

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Tom Ligon
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Selective ion-cyclotron resonance ...

Post by Tom Ligon »

What brought this up was a search for an old 2-meter 50W transmitter I used to have. I was looking for it the night before last and could not turn it up. Somewhere in the back of my mind, I may have donated it to EMC2. I know we considered hooking it up to PXL-1.

We've looked at ECR here. Electrons all have identical rest mass, so their Electron Cyclotron Resonance is a function of magnetic field strength, and their low mass means high frequency, typically in the microwave range. Ions do the dance, too, but their resonant frequency is dependent on both mass and magnetic field. VHF starts looking interesting. The transmitter in question worked at 144-149 MHz.

I did find a lightning arrestor and a power/SWR meter that I very specifically purchased to allow me to hook up to the apparatus, although we never got around to trying it (ECR was working beautifully).

Thinking in terms of practical DD machines, I'm wondering if a suitably tuned transmitter might be used to deliberately excite undesirable ions in some boundary region, helping expel them from the system? Or might this trick instead simply heat other ions via collisions and kill the annealing process? I always had a problem with hydrogen dilution of the deuterium when running tests on PXL-1 and WB-3.

MSimon
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Re: Selective ion-cyclotron resonance ...

Post by MSimon »

Tom Ligon wrote:What brought this up was a search for an old 2-meter 50W transmitter I used to have. I was looking for it the night before last and could not turn it up. Somewhere in the back of my mind, I may have donated it to EMC2. I know we considered hooking it up to PXL-1.

We've looked at ECR here. Electrons all have identical rest mass, so their Electron Cyclotron Resonance is a function of magnetic field strength, and their low mass means high frequency, typically in the microwave range. Ions do the dance, too, but their resonant frequency is dependent on both mass and magnetic field. VHF starts looking interesting. The transmitter in question worked at 144-149 MHz.

I did find a lightning arrestor and a power/SWR meter that I very specifically purchased to allow me to hook up to the apparatus, although we never got around to trying it (ECR was working beautifully).

Thinking in terms of practical DD machines, I'm wondering if a suitably tuned transmitter might be used to deliberately excite undesirable ions in some boundary region, helping expel them from the system? Or might this trick instead simply heat other ions via collisions and kill the annealing process? I always had a problem with hydrogen dilution of the deuterium when running tests on PXL-1 and WB-3.
Thinking in terms of practical DD machines, I'm wondering if a suitably tuned transmitter might be used to deliberately excite undesirable ions in some boundary region, helping expel them from the system?

Rick has suggested this.
Engineering is the art of making what you want from what you can get at a profit.

chrismb
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Re: Selective ion-cyclotron resonance ...

Post by chrismb »

Tom Ligon wrote:Thinking in terms of practical DD machines
Are you thinking only of Polywell-based devices, or are you opening this up to any candidate device?

If the latter, you might be interested to note section E.2.2 ["Potential New Approaches..">"Closed Orbit, High Velocity Resonant Device"] on p.270 of Todd Rider's thesis "Fundamental Limitations on Plasma Fusion Systems not in thermodynamic equilibrium". ( http://dspace.mit.edu/handle/1721.1/11412 ) Is this the *essential* property of the device you were considering?

Tom Ligon
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Post by Tom Ligon »

Dr. Rider's abstract pretty much tells his opinion. I've not found his arguments in other papers convincing because he builds in assumptions that prevent any possibility of the machines working. It may be he is right, but I'm more interested in seeing what EMC2 turns up experimentally. I note a 1995 date ... during that period Dr. Bussard attempted to explain the errors he said were in Rider's papers but said he could not get him to listen.

I confidently predict Todd Rider will never build a successful fusion machine.

My question was focussed on the DD Polywell, and specifically plays on one of Dr. Rider's arguments for why it won't work, that upscattered ions will not be contained by the potential well (he presumed the Polywell would thermalize almost instantly). The thought is to selectively pump hydrogen to higher energy so it is lost from the trap and does not dilute the deuterium. Hydrogen with sufficiently excess energy should pass thru the annealing band with comparitively little opportunity to participate in the annealing process, although it would probably knock out any D ion it hit.

MSimon
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Post by MSimon »

Tom Ligon wrote:Dr. Rider's abstract pretty much tells his opinion. I've not found his arguments in other papers convincing because he builds in assumptions that prevent any possibility of the machines working. It may be he is right, but I'm more interested in seeing what EMC2 turns up experimentally. I note a 1995 date ... during that period Dr. Bussard attempted to explain the errors he said were in Rider's papers but said he could not get him to listen.

I confidently predict Todd Rider will never build a successful fusion machine.

My question was focussed on the DD Polywell, and specifically plays on one of Dr. Rider's arguments for why it won't work, that upscattered ions will not be contained by the potential well (he presumed the Polywell would thermalize almost instantly). The thought is to selectively pump hydrogen to higher energy so it is lost from the trap and does not dilute the deuterium. Hydrogen with sufficiently excess energy should pass thru the annealing band with comparitively little opportunity to participate in the annealing process, although it would probably knock out any D ion it hit.
Are you thinking of the 40% difference in velocity rather than energy?

BTW as I understand it Rider is not even in physics any more.
Engineering is the art of making what you want from what you can get at a profit.

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