Lawaranceville E-Newsletter

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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Ivy Matt
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Post by Ivy Matt »

chrismb wrote:The graph is still up there [from last year].
If I may ask, the graph is still up where? I didn't notice it in any of the recent reports. Do you want them to purge it from their site? As a historian (of sorts—I received a minor in history) I find the idea rather disturbing.
Temperature, density, confinement time: pick any two.

Ivy Matt
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Post by Ivy Matt »

MSimon wrote:I'm making some assumptions of course. I assume the B field is maxed out and all they have to get more power is size.
What led you to those assumptions? :?
Temperature, density, confinement time: pick any two.

zapkitty
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Post by zapkitty »

Skipjack wrote: Now that I can fully agree with and I am sure they are aware of that too.
My guess is that they are simply going to treat the electrodes as expendable parts and hope that somone will come up with a solution for the problem some other day (basically, not "their" problem).
The FF plan has been to change out the electrodes and reform/recycle the material. For a long while the talk was 90 days between changeouts, but in a recent video Lerner said the plan was for 30 days of use... probably from the actual experience they've been getting.

But when considering this a drawback of FF remember that these are non-hazardous metal parts that bolt in place... and it will only take 9 hours for an FF unit to "cool down" enough for such maintenance. (pesky C11)

Given the other advantages of aneutronics in general and FF in particular I wonder if even bi-weekly core changeouts would be a hindrance to adoption... when compared to the maintenance overhead of any steam cycle plant.
Last edited by zapkitty on Sat May 21, 2011 1:37 am, edited 1 time in total.

Skipjack
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Post by Skipjack »

The FF plan has been to change out the electrodes and reform/recycle the material.
Yeah, that was my impression that they were shooting for something like that. With 30 days they are on the lower side. On the other hand the electrodes are not that expensive parts. Maybe somebody will find a better solution. If they can get their Focus Fusion thing going and if they can really do PB11, then this will spark a ton of research and someone will come up with something eventually. At least that is what I assume they are speculating will happen.

scalziand
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Post by scalziand »

Ivy Matt wrote:
chrismb wrote:The graph is still up there [from last year].
If I may ask, the graph is still up where? I didn't notice it in any of the recent reports. Do you want them to purge it from their site? As a historian (of sorts—I received a minor in history) I find the idea rather disturbing.
Here's a slightly different version of the graph with the dates removed from last year.

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

It also has a table detailing where the expected gains in yield will come from.

MSimon
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Post by MSimon »

Ivy Matt wrote:
MSimon wrote:I'm making some assumptions of course. I assume the B field is maxed out and all they have to get more power is size.
What led you to those assumptions? :?
To get more B field they need to pump in more current in a system where electrode erosion is already a BIG problem.

As I showed above - scaling will be a problem because they need to up the current in larger devices to keep the field constant.
Engineering is the art of making what you want from what you can get at a profit.

MSimon
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Post by MSimon »

I actually believe this device can work. Getting enough energy out of it to make it a worthwhile energy producer will be a real trick though.
Engineering is the art of making what you want from what you can get at a profit.

MSimon
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Post by MSimon »

Skipjack wrote:
Yeah. Electrode erosion is going to be a b****.
Now that I can fully agree with and I am sure they are aware of that too.
My guess is that they are simply going to treat the electrodes as expendable parts and hope that somone will come up with a solution for the problem some other day (basically, not "their" problem).
The question is: will the stuff given off from electrode erosion poison the reaction or short out the electrode?
Engineering is the art of making what you want from what you can get at a profit.

Ivy Matt
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Post by Ivy Matt »

scalziand wrote:Here's a slightly different version of the graph with the dates removed from last year.

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

It also has a table detailing where the expected gains in yield will come from.
Thanks! I was actually considering posting that page.
MSimon wrote:To get more B field they need to pump in more current in a system where electrode erosion is already a BIG problem.
Are we talking about the current FF-1 experiment here, or the hypothetical future commercial reactor that will be firing at 500 Hz? Right the now the big problem is just getting switches that don't prefire and spark plugs with insulators that don't shatter. Once they've got the new ruggedized switches all firing simultaneously at 45 kV without breakage (which will hopefully be soon), then they can worry about the problems that will be coming up next.
As I showed above - scaling will be a problem because they need to up the current in larger devices to keep the field constant.
According to my understanding, the idea is to up the current in the device they already have, and they're almost there now. Actually, once they're finished testing with deuterium, they'll be replacing the current electrodes with shorter ones. According to Lerner's hypothesis, smaller device + higher current ( + heavier fill gas ) = bigger bang. Of course, the device can only be so small before you need to make it out of unobtainium.
MSimon wrote:The question is: will the stuff given off from electrode erosion poison the reaction or short out the electrode?
That is a good question. I don't think it will have to be answered in the current phase of the experiment, but I guess engineers like to think ahead.
Temperature, density, confinement time: pick any two.

MSimon
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Post by MSimon »

It is not the length of the electrodes that is the problem. It is the diameter. The current needs to go up with the circumference. But that may only be a requirement if they want to keep the output energy pulse length constant.

I haven't delved into device operation for about a year and I only did that with intense focus (heh) for a couple of months so I'm a little hazy on the operational details.

I do remember they were getting intense B fields as the field collapsed.

Energy collection is going to be tricky but that can be dealt with (maybe) after the device is producing fusion.
Engineering is the art of making what you want from what you can get at a profit.

chrismb
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Post by chrismb »

Ivy Matt wrote:
chrismb wrote:The graph is still up there [from last year].
If I may ask, the graph is still up where? I didn't notice it in any of the recent reports. Do you want them to purge it from their site? As a historian (of sorts—I received a minor in history) I find the idea rather disturbing.
Try hitting 'quote' on my post and you'll see the URL for that image.

A bit of minimal-effort investigative journalism wouldn't go amiss here?? (Last argument over 'sources' someone threw at me was because they couldn't work out how to use the search bar in wiki! :roll: )

tomclarke
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Post by tomclarke »

MSimon wrote:It is not the length of the electrodes that is the problem. It is the diameter. The current needs to go up with the circumference. But that may only be a requirement if they want to keep the output energy pulse length constant.

I haven't delved into device operation for about a year and I only did that with intense focus (heh) for a couple of months so I'm a little hazy on the operational details.

I do remember they were getting intense B fields as the field collapsed.

Energy collection is going to be tricky but that can be dealt with (maybe) after the device is producing fusion.
They think now that exact symmetry in electrodes is necessary to get good pinch. That compounds the already probably intractable problem of electrode wear...

I like D-T colliding FRC idea more than this. The scaling seems no more implausible than the DPF scaling? the engineering would be a lot easier.

But I guess John Slough is less Hollywood scientist photogenic than Eric Lerner.

Skipjack
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Post by Skipjack »

I like D-T colliding FRC idea more than this. The scaling seems no more implausible than the DPF scaling? the engineering would be a lot easier.
I fully agree with that one. As I have said before, IMHO of all proposals that I have seen so far, Slough has the highest chance of success.
I do want to add though that Lerner is aiming a lot higher with PB11 in the DPF.
So the comparison is not completely fair.

ladajo
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Post by ladajo »

scalziand wrote:
Ivy Matt wrote:
chrismb wrote:The graph is still up there [from last year].
If I may ask, the graph is still up where? I didn't notice it in any of the recent reports. Do you want them to purge it from their site? As a historian (of sorts—I received a minor in history) I find the idea rather disturbing.
Here's a slightly different version of the graph with the dates removed from last year.

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

It also has a table detailing where the expected gains in yield will come from.
This is better, but it still should separate theory goals versus acheivements for the life of the project. The blue should extend to the base, not just to the lastest testing.
The graph as is indicates a flattening progress against "inflated" goals which can be percieved to be a re-alignment of the actual progress projection.

This can be argued as an indication of fraud and does not help them IMO.

Ivy Matt
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Joined: Sat May 01, 2010 6:43 am

Post by Ivy Matt »

chrismb wrote:Try hitting 'quote' on my post and you'll see the URL for that image.

A bit of minimal-effort investigative journalism wouldn't go amiss here?? (Last argument over 'sources' someone threw at me was because they couldn't work out how to use the search bar in wiki! :roll: )
I usually just right-click and select "view image", but all that tells me is that the image is located on LPP's website. What is the context? Did they link to it in one of their recent updates, or something?

I'll see your URL and raise you two:

http://www.lawrencevilleplasmaphysics.c ... &Itemid=90

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

This story (or these two stories, depending on how you count it) from June of last year is the only place, as far as I am aware, where this image shows up (not counting out-of-context links on Talk Polywell or elsewhere). As scalziand has pointed out, it was shortly thereafter superseded by the graph that appears in this story:

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

Image
The pink points in the chart above correspond to yields actually achieved so far.

The blue points correspond to LPP’s goals based on the theories they are testing.
I agree with ladajo that both graphs have problems. I assume LPP agrees as well, because as far as I am aware they have not reused them in any of their updates for nearly 11 months.
Temperature, density, confinement time: pick any two.

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