D Tibbets wrote: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
Go up thread. I run the numbers based on DPF graphs. .1W vs 10 MW = 1E8.
1E9 = 30 doublings so 1E8 = 27 doublings. I used 30 for convenience. Puts me off by a factor of 10. Not significant for this exercise.
Engineering is the art of making what you want from what you can get at a profit.
D Tibbets wrote: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
Go up thread. I run the numbers based on DPF graphs. .1W vs 10 MW = 1E8.
1E9 = 30 doublings so 1E8 = 27 doublings. I used 30 for convenience. Puts me off by a factor of 10. Not significant for this exercise.
OK, perhaps from your starting point the doublings would be almost 27 doublings. I was using my recollection that they were achieving a few hundred billion neutrons per shot in their best shots and I rounded up.. My starting point may have been higher on the chart than yours.
And I assume you mean 10^8 increase. 1^8 or 1E8 would not be much of an increase.
Go up thread. I run the numbers based on DPF graphs. .1W vs 10 MW = 1E8.
1E9 = 30 doublings so 1E8 = 27 doublings. I used 30 for convenience. Puts me off by a factor of 10. Not significant for this exercise.
OK, perhaps from your starting point the doublings would be almost 27 doublings. I was using my recollection that they were achieving a few hundred billion neutrons per shot in their best shots and I rounded up.. My starting point may have been higher on the chart than yours.
And I assume you mean 10^8 increase. 1^8 or 1E8 would not be much of an increase. :twisted:
Dan Tibbets
Uh. In physics notation 1E8 = 1 X 10^8
Engineering is the art of making what you want from what you can get at a profit.
Go up thread. I run the numbers based on DPF graphs. .1W vs 10 MW = 1E8.
1E9 = 30 doublings so 1E8 = 27 doublings. I used 30 for convenience. Puts me off by a factor of 10. Not significant for this exercise.
OK, perhaps from your starting point the doublings would be almost 27 doublings. I was using my recollection that they were achieving a few hundred billion neutrons per shot in their best shots and I rounded up.. My starting point may have been higher on the chart than yours.
And I assume you mean 10^8 increase. 1^8 or 1E8 would not be much of an increase.
Okay, so I was wrong about not hearing anything from LPP until August. The latest news is here.
Not all that much of an update, but there are some numbers—neutron counts, even. Meanwhile the FF-1 device is still being upgraded and is apparently expected to resume testing in August.
Oh, and I think they got the ITER completion date wrong. Last I heard it was 2019. 2025 sounds more like the target for break-even.
Temperature, density, confinement time: pick any two.
Giorgio wrote:I love the comparison pictures between the NIF and FOFU1 reaction chambers
Don't mention to the Big Fusion people that the DPF cores for pB11 will actually be even smaller than those currently used for DD testing. That would make them feel bad.
I know! Tell them instead that a working reaction chamber from a power generator will be at least a half meter larger in each dimension than the one Aaron is holding!
That should make them feel better... just don't mention that those chamber measurements would include the entirety of both of the power conversion assemblies...
Right now I think the better updates are to be found on Twitter:
On July 14, 2011 LPPX wrote:double-checking aluminum plates with the metal up on the machine, all within tolerances, go for snap-in bolts-Soon FoFu will flap its wings.
On July 18, 2011 LPPX wrote:aluminum transmission lines (ground plates) are being installed ;-D
Looks like the upgrade is almost complete and the experiment will finally be able to go forward again.
Temperature, density, confinement time: pick any two.
Looks like they're sticking with the business plan too - going for leverage via heavy xray applications first, energy generation is actually the 2nd product they're aiming at - very real.
looking forward to seeing that xray-onion thing coming off the drawing board soon too.
i suspect Eric Lerner will have no shortage of wana-be investors knocking at his door around now. So long as it remains his baby and this level of transparency and agility remains... great things perhaps...
I have big expectations from them too. If the aluminum plates will brig the expected results I am sure there will be a big surge of interest in their research.
Giorgio wrote:I have big expectations from them too. If the aluminum plates will brig the expected results I am sure there will be a big surge of interest in their research.
also, perfect lightweight (regenerative) shielding for their xray machines, and a perfect development test bed for Q>1 objectives. just block up the hole.
did they decide on aluminum already? is it optimum?
rcain wrote:did they decide on aluminum already? is it optimum?
If you talk about first wall there is not any optimum solution.
As all solutions would be compromise.
But aluminum or aluminum alloy can be considered as first wall material due to set of its properties.
If you talk about something else first wall, I do not know as did not read the thread from the beginning.
rcain wrote:did they decide on aluminum already? is it optimum?
If you talk about first wall there is not any optimum solution.
As all solutions would be compromise.
true.
Joseph Chikva wrote:
But aluminum or aluminum alloy can be considered as first wall material due to set of its properties.
also by the geometry of design in this case. i wonder about thermal scaling though. however, he plans small units only, so i'm confident he sees no problems in that area.
Joseph Chikva wrote:
If you talk about something else first wall, I do not know as did not read the thread from the beginning.
i recall reading the patent application (i think it was) - some other descriptions. very well known physics, in a great amount of detail. but a lot of engineering/implementation still to decide on.
i got the impression this can be/must be constructed as a pretty narrow-band device. some form of nano-scale composite/metamaterial might be interesting to consider?
rcain wrote:i got the impression this can be/must be constructed as a pretty narrow-band device. some form of nano-scale composite/metamaterial might be interesting to consider?
"Nano" - only a fashionable word.
May be in the future someone will create the material better answering to FW requirements. May be with utilization of nano-particles.
Now are considered stainless steel (SS) and aluminum I think first of all due to well known technology of their processing and acceptable enough set of other properties.
For ITER and NIF are considered main structure made from SS, and joined to that copper alloy modules with cooling channels + beryllium plates.
That would be the best choice as atom number of beryllium is equal to only 4 and in case of erosion they will less contaminate plasma.
As Bremstahlung intensity is proportional to atom number in square.
