alexjrgreen wrote:Art Carlson wrote:Since somebody asked me a couple days ago to make I sketch of what I thought the spacial structure of the electric potential looked like, I've been trying to tap all the pieces of my model into place.
What do you make of Joel G. Rogers' PIC Simulation of Polywell?
First, it's very strange to simulate a single point in parameter space and then use somebody's idea of scaling to extrapolate to reactor conditions. Why not simulate a second point and test the scaling yourself. Better still is 3 points to separate the B scaling from the R scaling.
Second, and more serious, is what happened to Gauss's Law? I am worried about those fans of electrons without ions. I would be very interested in knowing how big the charge per unit area is, but I can't figure it out. The information might be there, but it is hard to tease it out of the plots and statements. Have any of you been able to figure it out?
Related to this, take a look at the plot of the potential on p. 9 and compare it with the plot of the electron density on p. 8, concentrating on one of the corners of the tank, whose walls are held at 0 V. If there are electrons sitting out there on the diagonal and no ions, why doesn't the potential drop below zero?
Let's say this is the first presentation of a young post-doc just getting started on a new project. Once he gets the wrinkles ironed out - peer review would help that process - he might have an interesting tool to begin investigating polywell physics. (Too bad, though, that there is no data to which he can compare his results. OK, maybe one measurement by Krall of the electron loss time in the mirror regime.)