I am new here.

[kcdodd]

I just wanted to stop in and say hello. My name is Carter, and I am a recently graduated physics student (undergrad that is). I have followed fusor stuff since high school, when I just thought it made really cool pictures. haha. And became interested in the polywell approach only last year. I was really sad when I learned Dr. Bussard had passed away.

Anyhoo, I am going to try to join the club and write some simulation code. I found Indrek's website through the fusor.net site several months ago and basically copied some of what he had done in matlab my last semester in school (edit: you can see a couple plots on my website). But then I read up on the Vlasov equation and am currently coding a solver for it.

So, Hi!

[tonybarry]

Hello Kenneth,
Welcome to talk-polywell.

I had a look at your website, it was a good effort. There were some things I didn't understand. In the
graph:-

you have colour representing something. What is that something?

I like the idea of using Matlab. There are a number of real pluses to using it.
-it is known widely
-it compiles easily on several platforms (Win/Mac/Linux/Sun?)
-its functions are tested and known to return correct answers
-its graphical functions are easily accessed and manipulated
-multiprocessor support is built in using a couple of basic code constructs (forp instead of for, etc) and it hides the multiproc workings from the user
-the Distributed Computing Toolbox will run four cores (e.g. on a Mac 8-core beast) with no further licensing issues

On the downside, it is
-expensive (the DCT is Very Expensive, and if you have a worker farm, it's Horribly Expensive)
-slow (using the inbuilt functions is razor fast, but any discrete operations can take a lot longer than C would

I look forward to your next posts with interest.

Regards,
Tony Barry

[MSimon]

That is outstanding.

I've been here for a while and am just amazed at the progress being made.

I'm looking into Load/Store 32 bit MCUs with CAN bus for control and sensor interface. There are a lot of families available to choose from. I'm leaning towards the Freescale stuff because it has a nice feature set (up to six CAN buses on one chip) and they have a free assembler.

[drmike]

Howdy Carter!

Welcome to the fun. A Vlasov solver would be an excellent addition. Post your work in the "Theory" section as you make progress.

[TallDave]

For those wondering what the hell this is, I think this is it:

http://en.wikipedia.org/wiki/Double_lay ... n_equation

In general the plasma distributions near a double layer are necessarily strongly non-Maxwellian, and therefore inaccessible to fluid models. In order to analyse double layers in full generality, the plasma must be described using the particle distribution function , which describes the number of particles of species α having approximately the velocity near the place and time t.

The Vlasov-Poisson equations give the time-dependent interaction of a plasma (described using the particle distribution) with its self-consistent electric field. The Vlasov-Poisson equations are a combination of the Vlasov equations for each species α (also called the collisionless Boltzmann equation (CBE). We take the nonrelativistic zero-magnetic field limit);


and Poisson’s equation:


Here qα is the particle’s electric charge, mα is the particle’s mass, is the electric field, the electric potential and ρ is the electric charge density.

[kcdodd]

Thank you for the warm welcome. In that plot colors in the graph is only to distinguish each trace. There are about 50 different traces.

And that is related. The vlasov equation uses a particle density function which exists in 6-D phase space, and uses both electric and magnetic field solutions. At least if you are simulating in three dimensions, which is what I am coding. You can imagine it would be nearly impossible to even store a 6-D grid in the average computers memory. A 100 element/axis grid would have 100^6 = 10^12 points. That'd be 4TB assuming only 4 bytes per point, which is unlikely. So I have coded an adaptive mesh, which becomes more refined in areas where the magnitude of the second derivative of the density function is higher. I still wont know if it will be enough to fit it into the memory though until it actually trys to run.

[hanelyp]

http://en.wikipedia.org/wiki/Double_layer_%28plasma%29

That definitely relates to polywell operation.

[Jeff Peachman]

I took this thread as an inspiration to register my own login. I've been lurking here for a couple months, and have read a majority of the posts here. I look forward to contributing here since so many of you seem to share many of the same interests I have. Here's a few quick facts about myself; maybe you can see why I couldn't be a lurker any longer:

-I've been following IEC (Hirsch-Farnsworth fusors) since highschool, when I read Tom Ligon's article (and I was very suprised when I first recognized the name on this site, hi Tom).

-I've been following polywell since Bussard's Google Talk.

-I'm now an Aerospace Engineering student in my senior year, and planning to get a masters in Space Systems Engineering.

-Beyond polywell and space exploration, I'm very interested Ray Kurzweil's work, automotive technology (particularly high mpg hybrids or electrics. I'm really hoping EESTOR is real but I have my doubts), economics, and politics.

-By and all, I'm gunning for polywell and really hope it works to help "save the world" and, of course, make our space activities a lot more interesting.

Lastly I'm encoraging anyone else out there just reading for the past few months like I have to say hello.

[MSimon]

Hello Jeff,

Welcome aboard. Have fun. Learn a lot.

[Jeff Peachman]

MSimon,

Thanks for the welcome. I was actually wondering recently how you came to learn so much about plasma physics. From what I picked up from other posts I thought you were an aerospace engineer by profession (Avionics maybe?).

Actually theres a lot of people here who seem to know a lot more than I've been able to teach myself so far, but I'll just have to keep trying =)

-Jeff

[Tom Ligon]

Welcome aboard, Jeff! You've come to the right place.

I have first-hand experience working with Dr. Bussard, but at least half of these guys are more up on both theory and hardware than I am.

[MSimon]

MSimon,

Thanks for the welcome. I was actually wondering recently how you came to learn so much about plasma physics. From what I picked up from other posts I thought you were an aerospace engineer by profession (Avionics maybe?).

Actually theres a lot of people here who seem to know a lot more than I've been able to teach myself so far, but I'll just have to keep trying =)

-Jeff

I can give you an exact date for the beginning of my education if I looked it up. Aprox. mid-Nov 2006. At that point in time my knowledge of plasma physics and the BFR was zero. I knew about vacuum tubes, fission reactors, and aerospace engineering (power distribution and controls). Then I saw Dr. B's Google talk. It changed my life.

I have left up my original pieces (at the IEC Fusion Tech. blog) on my understanding of the BFR concept. There are better more correct explanations available but I wanted people to be able to see the evolution in my understanding. It takes time.

All the concepts are simple, but their interrelations are complex because nothing can be isolated. Plasma reacts to everything including itself.

[drmike]

Welcome Jeff!

You never stop learning. There is not enough time to learn everything!
Focus on what is fun and interesting and after a few decades you will know
a huge amount of detail about a few things, or a few details about a huge
amount of things.

Doesn't matter - it's fun either way! But get through school first