Alternative Reactor Design

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Richard Hull
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Re: Alternative Reactor Design

Post by Richard Hull » Sun Jan 07, 2018 4:09 pm

There remains no source of continuous, un-interrupted, intense, stable neutron flux on earth, other than a functioning fission reactor..... Period!
Fusion??? Phooey......

Nothing on this planet breeds fission or fusion fuel like a real fission reactor. All other neutron sources don't rise to the elevated level of even dis-honorable mention. At best, they are struggling little putt-putt boats in a child's bathtub in comparison.

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Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Rich Feldman
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Re: Alternative Reactor Design

Post by Rich Feldman » Tue Jan 09, 2018 10:32 am

There are some world-class accelerator based neutron sources that get pretty darn close (as laboratory beamlines for studying materials or basic physics). When high neutron fluences are needed for production processes, whether breeding fuel or doping silicon ingots, the work has to be within or very close to a fission reactor core, like Richard said.
fluxes.JPG
Found that in a paper written by a spallation enthusiast: http://www.iaea.org/inis/collection/NCL ... 099436.pdf
It also has a tantalizing mention of pulsed fission reactors.
flux2.JPG
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Re: Alternative Reactor Design

Post by JoseRey » Tue Jan 09, 2018 9:10 pm

Rich Feldman wrote:
Tue Jan 09, 2018 10:32 am
There are some world-class accelerator based neutron sources that get pretty darn close (as laboratory beamlines for studying materials or basic physics). When high neutron fluences are needed for production processes, whether breeding fuel or doping silicon ingots, the work has to be within or very close to a fission reactor core, like Richard said.

fluxes.JPG
Found that in a paper written by a spallation enthusiast: http://www.iaea.org/inis/collection/NCL ... 099436.pdf
It also has a tantalizing mention of pulsed fission reactors.flux2.JPG
But spallation sources typically don't work continuously but pulsed, so background measurements can be taken and compared to those with the pulse.

Integrated over time the amount of neutrons produced by a spallation installations is much lower that a fission reactor, but they are ok to test products, processes and instruments, for continuous breeding a fission reactor can't be beaten, it's only necessary to have a right place to put your stuff.

Anyway, fusors neutron output is soooo low that it's basically useless, and theoretical big fusion reactor would harvest the kinetic energy, to create electricity, so they aren't suited either

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Re: Alternative Reactor Design

Post by Richard Hull » Tue Jan 09, 2018 9:37 pm

Thanks for recognizing that I was talking about absolute, 100% continuous neutron flux systems that are start'em up then walk away for months, years with a good stable flux. Only one exists....Fission reactors. Waste heat makes electricity. Fission reactor neutrons can make more fission and fusion fuel if you've got the guts to breed while putting out a giga-watt or more of electricity. About as straight forward a continuous, useful, neutron source as man will have into the very distant future.

Pretty darn close wins no cigar..........Close only counts in horse shoes and hand grenades.

Currently, we have no guts and therefore, will have no glory

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Re: Alternative Reactor Design

Post by danielchristensen » Wed Feb 14, 2018 5:53 pm

Hi all,

We actually operate a system that is conceptually similar to this idea at Northwest Nuclear Labs. I was involved with the project that ended up retrofitting the central cathode during the 2014-2015 school year. We did not, however, experiment with magnets because would cause complexity that is not necessarily beneficial to a team of high school freshmen that have very little experience around fusors. We were already operating a cathode that differed from the traditional geodesic grid, which can be seen in the image below (which is a helium plasma instead of deuterium).
Helium Plasma.png

My team went a step further and implemented a single ring as a cathode, which is seen in the below images. The top photo comes from my current research into Langmuir probe plasma imaging, which is a story for another time.
Probe in Plasma 3.jpg
Expanding Deuterium Plasma.jpg
When we implemented the linear cathode, we saw an increase in neutron flux of around 12%, which brought us up to the range of 1 million neutrons per second. We originally attributed this to higher plasma density, which was based solely on visual evidence (brighter plasma). We plan to test this claim once our imaging system is operational.

Regards,
Daniel Christensen

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Richard Hull
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Re: Alternative Reactor Design

Post by Richard Hull » Wed Feb 14, 2018 9:05 pm

Thanks Daniel. A number of years ago Jon Rosenstiel experimented with a number of different grids even a solid ball and it did fusion! The grid design is not hyper critical. A needle point will do fusion just fine. Doug Coulter has used only a cylinder grid in his superb fusor for years. This is just a form of a ring with large width. We never touted or offered the spherical or the geodesic as as the absolute and only grid, but just a typical original design.

We look forward to your future reports on the ring grid. Keep us in the loop. We are now seeing, through others efforts, that a spherical chamber of larger size is not needed. Smaller may be better.

Folks pokin' around in the fusor area is always a good thing. Remember, "Research is what I'm doing when I don't know what I am doing."

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Patrick Lindecker
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Re: Alternative Reactor Design

Post by Patrick Lindecker » Sun Nov 25, 2018 11:51 pm

Hello Dan,

>Beam- beam fusion has advantages, but it is more challenging. If you can focus two opposing beams of fusable ions through a tiny
>intercept area and have at least some degree of ion repeat passes, even a low density , perhaps below the Brillion limit might
>produce enough fusion , at least for the fusion/ fission approach. But, if this was easy, then it would have been done long ago.

Old but interesting post. So one remark:

I simulated this type of working in the following conditions. I supposed a symmetrical linear trap with Einzel lenses for ions confinement. I supposed a D2 GFIS (to say very brillant) (at 12 KV) ion source in one side and a T2 GFIS ion source (at 12 KV) in the other side. Voltage on electrode is reasonable (<200 kV) (to avoid a discharge beween electrodes). If you suppose that the GFIS source ions supply ions in an area such that the diameter is equal to 2 nm (0.002 microns), with a current of 7 mA (if fact impossible for a GFIS but it is an hypothesis), the trajectories being parallel (i.e the source emittance being equal to 0), it works (in simulation ☺). You can produce up to 5000 W of fusion power for 7x12x2=168 W of kinetic power. The Einzel lenses are able to confine (or lets's say able to limit) the space charge effect and coulombian collisions effect. The problem is that source ions emittance is not equal to 0 (for example a GFIS sends ions inside a solid angle of about 1°). Einzel lenses cannot prevent trajectories to quit the ideal tube of 2 nm of diameter. I tried also with a magnetic field up to 1 Tesla, but it does not work (as it is too much weak).

One solution would be to suppose very high voltages on electrodes (let's say 10 MV or more), to make Einzel lenses extremely efficient which is not possible without discharge and/or very high magnetic fields which is not possible either.

So there is no trivial solutions (even simulated)...

Patrick

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Re: Alternative Reactor Design

Post by Niels Geerits » Fri Nov 30, 2018 5:41 pm

There actually is a continuous spallation source at PSI. I think it produces about 1 order of magnitude fewer neutrons than the ILL reactor. Though other spallation sources are pulsed, this can be advantagous depending on your application, since the pulsed nature gives you wavelength resolution. So it really depends on your application which source is more suited. If flux (integrated over energy) is the only parameter you are after then yes a power generating reactor wins everytime: ILL is the highest power research reactor at 60MW or so a power generating reactor will easily be in the GW range. Useful for breeding sure, they aren't used for science AFAIK.
Last edited by Niels Geerits on Sat Dec 01, 2018 3:54 pm, edited 1 time in total.

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Re: Alternative Reactor Design

Post by John Futter » Fri Nov 30, 2018 11:35 pm

For gods sake stop repeating what others have written
you are not paying for the server data storage are you????
We can all read and seeing it posted again is a pain in the backside

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Re: Alternative Reactor Design

Post by Richard Hull » Sat Dec 01, 2018 5:20 am

It seems only John and I press for this noise reduction factor on a regular basis.

This is not your average zip through blog or forum but a serious forum of relatively smart and serious folks who can read and do read each and every thread and can actually remember key points in the thread's previous main subject and its many replies.

Quoting is OK if you see some good quotes or ideas worth considering from other entirely different posted past threads to perhaps bring home a number of points in a new thread that you deem relevant to you effort within the new thread. A reference to the URL of the thread from which you dragged over the quote is always appreciated.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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