Energy conversion...

[Heath_h49008]

This might not be "bleeding edge" enough for this crowd, but I haven't noticed this on the board.


http://www.askmar.com/Fusion_files/Venetian%20Blind.pdf

It's from Livermore, so you may already have it...

[Skipjack]

I am pretty sure that this has been discussed here before. At least it sounds very familiar to me.

[Betruger]

It was discussed. At least one person argued it had technical issues with it, I can't recall who.

[MSimon]

The issue is collection voltages vs. particle energy distributions.

Since particle energy distributions are unknown there is no way to tell (even BOE) how it will work.

[Heath_h49008]

With a WB type core, we should have a good idea of where our high energy products will exit. Unless I'm forgetting something, we should have predictable "hot spots" that correspond to the cusp openings.

[MSimon]

With a WB type core, we should have a good idea of where our high energy products will exit. Unless I'm forgetting something, we should have predictable "hot spots" that correspond to the cusp openings.

If the gyroradius of the alphas is smaller than the "holes" in the donuts then the alphas should just come out of the holes. It depends on the magnetic fields. A 3T field with a 1 m hole works. Scale that up or down (6T field for .5 m hole for example).

Since the assumed parameter for a working reactor is 10 T for a 2 m hole it should work fine.

[KitemanSA]

If you search back thru the old topics, you will find a series of postings with some pretty good graphics of such a system integrated with a Polywell. However, it was then dropped because "oops, the alphas go out in every direction!" Only after the topic had been dropped for numerous months did Dr. N. say, "nope, the alphas would preferentially exit the cusps after all". Maybe it is time to reprise the old discussions?

[Heath_h49008]

I wouldn't be opposed. I'm a bit new here, and not a particle physicist... I can be a bit slow to reach the same velocity as everyone else in a conversation.

[chrismb]

If you search back thru the old topics, you will find a series of postings with some pretty good graphics of such a system integrated with a Polywell. However, it was then dropped because "oops, the alphas go out in every direction!" Only after the topic had been dropped for numerous months did Dr. N. say, "nope, the alphas would preferentially exit the cusps after all". Maybe it is time to reprise the old discussions?

weeell.. not really. If polywell works as stamped, I might even agree the alphas come out predictably. The issue isn't the distribution of their directions but the distribution of their energies, as MSimon states [actually demonstrating *some* knowledge of the plasma physics well enough].

[KitemanSA]

weeell.. not really. If polywell works as stamped, I might even agree the alphas come out predictably. The issue isn't the distribution of their directions but the distribution of their energies, as MSimon states [actually demonstrating *some* knowledge of the plasma physics well enough].

IIRC, the discussions back then spent a significant effort on handling the distribution of energies. Don't condemn until you read.

[mad_derek]

IIRC, the discussions back then spent a significant effort on handling the distribution of energies. Don't condemn until you read.

Yes, you do.

The real question is: if it works how many grids are needed such that the released energy cost is lowest.

[MSimon]

IIRC, the discussions back then spent a significant effort on handling the distribution of energies. Don't condemn until you read.

Yes, you do.

The real question is: if it works how many grids are needed such that the released energy cost is lowest.

And that question is not only one of the number of grids but also how to handle the residual heat load.

[KitemanSA]

One other point for optimization that I don't recall being dicussing in THIS context but has been discussed in general is the sputtered material due to non-optimized conversion. Thoughts?

[chrismb]

IIRC, the discussions back then spent a significant effort on handling the distribution of energies. Don't condemn until you read.

I read, commented, re-read, re-commented, &c. and now feel well placed to condemn. Show me the extra-ordinary proof this extra-ordinary thing can work, and whoever does so will get a "fancy that, it works!!" out of me.

[MSimon]

IIRC, the discussions back then spent a significant effort on handling the distribution of energies. Don't condemn until you read. :wink:

I read, commented, re-read, re-commented, &c. and now feel well placed to condemn. Show me the extra-ordinary proof this extra-ordinary thing can work, and whoever does so will get a "fancy that, it works!!" out of me.

It is not extraordinary chris. As far as I can tell it is just electrostatics. If you can accelerate particles with electrostatics why can't you decelerate them?