Lawaranceville E-Newsletter
I'm not certain for what reason they will be using shorter electrodes for p+B11, but I believe Lerner's hypothesis is that a smaller electrode diameter is better, except that smaller electrodes are less able to withstand the extreme conditions of the plasma focus. I think Lerner feels he has found the right diameter, and will only be changing other parameters to get the results he is looking for. The parameters that I am aware of are voltage, fill gas pressure, and fill gas composition (in addition to electrode length). None of those parameters are fully tested yet, and mechanical problems have prevented them from achieving their target voltage to date.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.
Temperature, density, confinement time: pick any two.
I'm not sure what that has to do with things. I'd say most of LPP's publicity comes from a small, barely alive forum, with a few active members, and, much more importantly, more-or-less regular updates with a fair amount of detail.tomclarke wrote:But I guess John Slough is less Hollywood scientist photogenic than Eric Lerner.
And don't forget that John Slough was recently featured in Popular Mechanics. I'm fairly optimistic he'll find some funding soon.
Temperature, density, confinement time: pick any two.
Again, why pull them? To hide the fact that they were naively optimistic about a year ago?ladajo wrote:They should either pull them or update them. Maybe they are afriad of what they show? Flattened progress curve?
Maybe they should update them, but I think they have more pressing things to worry about. I expect once they get the new switches in place it will add a little "S" to their curve. Maybe they're waiting for that.
I don't see the point in worrying that a relatively obscure news story from a year ago will give people the wrong impression. All you have to do is read the more recent news stories to see what has happened since. Of course, that's assuming you found the graphs from the news stories rather than some other source....
Temperature, density, confinement time: pick any two.
The table - of where the increase comes from - is helpful.ladajo wrote:Don;t get me wrong, I think they are doing good work. And I think that they may have a shot. However, the graphs are not helping IMO.
If they published a running total of what multiplier had been acheived for each line of the table, and also what problems were preventing the multiplier, if they have tries for it but not got it, that would be perfect.
But in reality I think they are pretty good at PR. they have pretty pictures which glow violet. And twitter. And blogs.
EMC2, if it did that, would develop a cadre of breathless supporters all keen to raise funds for WB-D.
But maybe EMC2 is more concerned with working out true scaling laws from WB-8/WB-8.1.
They published tidbits of that here and there on their news releases.tomclarke wrote:If they published a running total of what multiplier had been acheived for each line of the table, and also what problems were preventing the multiplier, if they have tries for it but not got it, that would be perfect.
I remember that someone made a post of the expected increase according to the modified parameter.
Let me see if I can find it back and I will post it here.
They have not got the benefit from axial field that they want, but they have been struggling with no way to get consistent pinches until very recently, so do not give up help.Giorgio wrote:They published tidbits of that here and there on their news releases.tomclarke wrote:If they published a running total of what multiplier had been acheived for each line of the table, and also what problems were preventing the multiplier, if they have tries for it but not got it, that would be perfect.
I remember that someone made a post of the expected increase according to the modified parameter.
Let me see if I can find it back and I will post it here.
In fact that is how it all started. It is why TP is here. There used to be a rather large fan base. Now it is down to the hard core. But even the hard core admit that there is a fair to strong possibility it won't work. Compare and contrast with the Rossi fans. Or the EEStor fans a year ago.KitemanSA wrote:If the Navy funding ever stops, I suspect you will see that REAL soon! :Dtomclarke wrote: EMC2, if it did that, would develop a cadre of breathless supporters all keen to raise funds for WB-D.
Engineering is the art of making what you want from what you can get at a profit.
MSimon wrote:But there is still the scaling problem. If the scaling is r^3 can they keep doubling the size of the device ~10X power every month? For 10 months? A doubling in size every 3 months would still be very good. Where is the progress?
A DPF scales differently. Output goes linear with size, so increasing the size only allows you to increase I in a similar manner.Ivy Matt wrote:I'm not certain for what reason they will be using shorter electrodes for p+B11, but I believe Lerner's hypothesis is that a smaller electrode diameter is better, except that smaller electrodes are less able to withstand the extreme conditions of the plasma focus. I think Lerner feels he has found the right diameter, and will only be changing other parameters to get the results he is looking for. The parameters that I am aware of are voltage, fill gas pressure, and fill gas composition (in addition to electrode length). None of those parameters are fully tested yet, and mechanical problems have prevented them from achieving their target voltage to date.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.
The important scaling factor is I, as http://nextbigfuture.com/2011/05/new-sw ... lasma.html says. I don't know if it's I^5 or I^7, but it's something around that.
So the goal is to minimize size of the electrodes and to maximize amperage without breaking anything. And the plasma should form somewhat nicely.
Actually it is worse than that. If you double the circumference you HAVE to double the current to keep the B field constant.A DPF scales differently. Output goes linear with size, so increasing the size only allows you to increase I in a similar manner.
Now suppose you need to gain 30 doublings of power to get up to the desired energy output. You need roughly 40 X as much current (as I showed in a previous comment).
Peachy keen until the last couple of doublings where you get powers in the MW range. It will be difficult to cool a small device in such a thermal field. And that is true whether or not the I scaling factor is I^3 (my guess) or I^5 or I^7.
That doesn't make the device useless. It might be good as a pulsed neutron source.
Engineering is the art of making what you want from what you can get at a profit.
I'm shooting from the hip so I may be off, but if DPF has been reaching ~ 10^12 fusions per shot, then 30 doublings would be 1,000,000,000 X. That would be ~ 10^21 fusions per shot. If 1 billion fusions (10^9) equates to ~ 1 milliwatt of fusion power then this would represent ~ 1 billion watts per shot. Assuming 10 shots per second would result in ~ 10 GW.
As DPF is expected to operate closer to 1-10 million watts, the more appropriate number of doublings would be closer to 20 (1 million X). My numbers may be off by an order of magnitude or more, but that still leaves the doubling at ~ 23-27.
That eliminates the last few doublings that you say are increasingly difficult. Obviously still a challenge, but ~ 10-1,000 X less so that your numbers suggest.
Dan Tibbets
As DPF is expected to operate closer to 1-10 million watts, the more appropriate number of doublings would be closer to 20 (1 million X). My numbers may be off by an order of magnitude or more, but that still leaves the doubling at ~ 23-27.
That eliminates the last few doublings that you say are increasingly difficult. Obviously still a challenge, but ~ 10-1,000 X less so that your numbers suggest.
Dan Tibbets
To error is human... and I'm very human.