Posted: Sat Feb 07, 2009 5:21 pm
A much better place for it, as whatever the merits or demerits of these arguments, they don't belong in "News".
a discussion forum for Polywell fusion
https://talk-polywell.org/bb/
On behalf of the community, I express our gratefulness for this piece of clarification.What of the poor electrons shed by the deuterium ionized just inside the magrid? What are they to do? The fast electrons converge on the center volume. Let's assume they have sufficient current to space-charge-limit the center: they will lose their kinetic energy as the potential reaches something approaching the cathode potential from which they were emitted: a fully developed potential well inside the magrid. The cold electrons can't go there because they lack the kinetic energy to overcome the potential. Likewise they can't go outside the magrid toward the cathodic wall potential. What is left for them? Attempt to get to the anode, the magrid. But they are discouraged from a direct path by the encircling magnetic fields. All they can do is slide along the magnetic field, taking little jumps where they can to sneak up on the magrid, oscillating in a path that avoids the cathodic areas. There is one spot where they can do this. The cusps. The cusps are the home for cold electrons. What the cold electrons do in the cusps will be vitally important in understanding the behavior of the machine. And they're just as negatively charged as the fast electrons.
May I humbly ask for your closer considerations behind this acclamation?I am particularly looking forward to showing that even electrons at the wall potential and cold ions at the plasma edge will not save you from massive energy losses.
A man with a small soul builds a strong shell around his little thoughts. We are not here to win a contest, we are here to exchange arguments, thereby reaching a standpoint on a higher level.Useless snide remarks like these are not getting the understanding advanced
"Modern organisational theory" was devised by a variety of people from all walks of life and who freely express their opinions in a structured and relaxed way.Munchausen wrote:Modern organisational theory points out that good decisions are generally made in an environment where knowledgeable people from a variety of the walks of of life may freely express their opinions in a structured and relaxed way.
I challenge you to name a great scientific advance made by a group of relaxed people devised from a variety of walks of life.Munchausen wrote:A major point of the science of history is that a society where the elite can isolate themselves from the consequences of their actions generally tend to make less than ideal decisions.
An aspergers-type engineering/science geek with a lack of social skills is the archetypal source of all our great scientific advances. In this case I am sure you could name some exceptions, but on the whole for every big-souled, friendly, warm and caring advancor of human scientific and engineering knowledge, I will name you ten who are miserable gits and I will name you one-for-one those who either killed themselves or ended their days as burnt-out rejects of society.Munchausen wrote: A man with a small soul builds a strong shell around his little thoughts.
As this is a news item, I will justify my rant by concluding that Focus Fusion has been awarded a patent last week;Munchausen wrote:We are not here to win a contest, we are here to exchange arguments, thereby reaching a standpoint on a higher level.
Then a few thousand years ago, geeks evolved, we developed agriculture, and we became civilized.Munchausen wrote:Modern anthropological research shows that during the quarter of amilion years before the advent of agriculture, man evolved into a creature who spends an unproportional amount of time on social interactions.
Lets not get personal.An aspergers-type engineering/science geek with a lack of social skills is the archetypal source of all our great scientific advances. In this case I am sure you could name some exceptions, but on the whole for every big-souled, friendly, warm and caring advancor of human scientific and engineering knowledge, I will name you ten who are miserable gits and I will name you one-for-one those who either killed themselves or ended their days as burnt-out rejects of society.
Getting personal requires the identification of a specific 'person'. Who did you have in mind?MSimon wrote: Lets not get personal.
Ah, that brings us back to electron cusp plugging I believe. Very intriguing stuff.Even in a machine in which the walls are clearly an anode, the cusps can block. I think Rick may finally be getting a glimmer of why, but I've suspected a role for cold electrons since about a week after the event.
Sorry, Rick, I overlooked this comment until now.rnebel wrote:OK Art. I'm game. We don't know if the cusps are quasi-neutral. Use your theory and give me a quantitative prediction as to how the WB-7 will behave.
I've been busy.PolyGirl wrote:Following up from a week ago (Google figures seem to jump around from one end of the Earth to the other end and from week to week).Oh and just for fun:
- Robert Bussard gives 78,500
Bussard Fusion gives 31,000
Polywell Fusion 16,000
Bussard Polywell gives 6,110
Bussard Polywell Fusion gives 13,700Now do not let that go to your head
- Msimon Fusion gives 645,000
Regards
Polygirl
The way I read it, he was game for you to start an argument on those premises (which I get the impression are incorrect), to see what your (blind) prediction was, and compare that to what the actual WB7 showed. Not necessarily a fully detailed model of the polywell, just anything to see how accurate your predictions/modeling is. Wouldn't you say it's fair enough for the roles to be reversed for once?Art Carlson wrote:I am disappointed and puzzled that you say we don't know if the cusps are quasi-neutral. Do we not know the rough geometry of the cusps, or do we not know the voltages on the magrid, or do we not know the electron density? Not much else goes into the calculation.
I'm not sure this is the right way to think about the problem. Since there is a field null at the center, any plasma there automatically has beta=1. It may be that an underpowered machine will technically produce a beta=1 plasma, but with a smaller volume and a magnetic field which is a smaller fraction of the field at the coils. Another issue may be whether the sheath takes on its minimum thickness or not.Solo wrote:I suspect that the machine is not going to run at Beta=1 without some encouragement: if the cusp sheilding voltage and/or ion loss is too high, the plasma density is going to be the variable that takes the hit until things balance out.