Search found 78 matches

by prestonbarrows
Fri Sep 05, 2014 9:20 pm
Forum: Design
Topic: Simulation software : OOPIC
Replies: 26
Views: 24849

Re: Simulation software : OOPIC

Matt, there is something wrong with your magnetic plots. From Maxwell's equations, the divergence of B is equal to zero. That is not the case for your plots, clearly so near the center. Also, the magnitude of B would go to zero at the origin.
by prestonbarrows
Sun Aug 31, 2014 11:48 pm
Forum: Design
Topic: Simulation software : OOPIC
Replies: 26
Views: 24849

Re: Simulation software : OOPIC

happyjack27 wrote:doesn't sound like very good programming.
That's because it is 20+ years old. Check out Tech-X and Vorpral. That is the newest interation and is fully 3D E-M.
by prestonbarrows
Thu Jul 31, 2014 1:02 am
Forum: News
Topic: Magnets for fusion energy: A revolutionary manufacturing met
Replies: 5
Views: 2858

Re: Magnets for fusion energy: A revolutionary manufacturing

Biter magnets are pretty amazing, but can't really be used on geometries needed for tokamaks/polywell. They need to be long small bore solenoids. I believe JET still holds the record for non-SC tokamak field strength. The design specifics of systems of that scale are out of my range of experience th...
by prestonbarrows
Mon Jul 28, 2014 5:40 am
Forum: News
Topic: Magnets for fusion energy: A revolutionary manufacturing met
Replies: 5
Views: 2858

Re: Magnets for fusion energy: A revolutionary manufacturing

Getting 0.1T from water cooled copper on the order of 20 cm in diameter is fairly easy to do for continuous duty. This is around the 1-2kW power range. I have never seen a continuous water cooled copper coil get close to 1T, maybe someone has examples of this though. The trade off comes between the ...
by prestonbarrows
Mon Jul 28, 2014 5:12 am
Forum: News
Topic: Video Composite of a Shot on WB8
Replies: 3
Views: 3913

Re: Video Composite of a Shot on WB8

Matt,
These images are from the 'high beta test device', not WB-8.
by prestonbarrows
Tue Jul 22, 2014 4:18 pm
Forum: News
Topic: General Fusion in the news
Replies: 476
Views: 212002

Re: General Fusion in the news

Sorry typo, edited to fix. Those numbers are from "The advent of clean nuclear fusion - superperformance space power and propulsion". My point is that top of the line, commercial, continuous duty, electric neutron generators today are on the order of 1E9 to 1E12 n/s DD or DT. This is only on the ord...
by prestonbarrows
Mon Jul 21, 2014 10:01 pm
Forum: News
Topic: General Fusion in the news
Replies: 476
Views: 212002

Re: General Fusion in the news

Polywell probably can argue that it's a good neutron source, but how much better than other neutron sources is it? The only published numbers that I am aware of regarding Polywell neutron output are ~2*10^5 n/pulse at ~10^9 n/s. These numbers are from an info-dump by Bussard before his death and no...
by prestonbarrows
Thu Apr 17, 2014 1:35 am
Forum: Theory
Topic: lowdown on scattering
Replies: 6
Views: 2895

Re: lowdown on scattering

For the most part, two separate beams colliding head on is the same as a single beam with twice the energy into a stationary gas target. In general, the coulomb scattering cross-section is on the order of 100's of times that of the fusion cross section. This means that on average there are ~100 coll...
by prestonbarrows
Fri Mar 21, 2014 1:03 am
Forum: Theory
Topic: Electron injection as an engineering issue
Replies: 31
Views: 9637

Re: Electron injection as an engineering issue

First, are you sure that 45A is the electron beam current and not just the heating current through the filament? "45 Amps and ~ 12 (or 24,36...) volts" is about right for a resistive element; imagine a plain old 500W DC incandescent car headlamp or laying a resistor across a car battery. This seems ...
by prestonbarrows
Thu Mar 06, 2014 6:53 am
Forum: Theory
Topic: Rough thoughts on CSI second talk
Replies: 24
Views: 8266

Re: Rough thoughts on CSI second talk

Plasma Physics via Computer Simulation by Birdsall and Langdon is probably the best explanation of how PIC codes work. The first few chapters clearly go through all the mathematical nuts and bolts of using finite grids to describe fields and interactions between discrete particles with these grids....
by prestonbarrows
Sun Mar 02, 2014 2:44 am
Forum: Theory
Topic: Alternative to CUDA modeling
Replies: 5
Views: 3369

Re: Alternative to CUDA modeling

Birdsall and Langdon is the best place to get the basics of PIC codes. Cython is a good python package to get things running in C without having to actually learn C. Pycuda or pyopengl are good python packages for crunching numbers on a GPU. Numpy is a good middle ground for crunching large arrays o...
by prestonbarrows
Fri Feb 21, 2014 3:54 am
Forum: News
Topic: 2014 Dark Horse Trifecta Year?
Replies: 101
Views: 39144

Re: 2014 Dark Horse Trifecta Year?

I would say the current was the same as the coils, however the geometric configuration was not conducive to field concentration, thus they were unprotected. There would be the same current through the connector 'nubs' as any coil assuming they are all in series. However, there would be far fewer am...
by prestonbarrows
Fri Feb 14, 2014 2:55 am
Forum: Theory
Topic: New Post is up.
Replies: 9
Views: 4832

Re: New Post is up.

Vlasov-Poisson is a set of equations which can numerically approximate a plasma. There is more or less a spectrum of modeling approaches; solving for the trajectories of individual particles on one end and using fluid-like dynamics on the other end. Ideally, you would solve the trajectory of each io...
by prestonbarrows
Thu Feb 13, 2014 1:34 am
Forum: News
Topic: 2014 Dark Horse Trifecta Year?
Replies: 101
Views: 39144

Re: 2014 Dark Horse Trifecta Year?

A FRC plasmoid is created at each end of the device. The two plasmoids are accelerated, translated using pulsed magnetic fields until they are colliding in a central burn chamber. The burn chamber is surrounded by a simple cylindrical lithium blanket. All the expensive equipment is at the far ends ...
by prestonbarrows
Wed Feb 12, 2014 2:51 am
Forum: News
Topic: 2014 Dark Horse Trifecta Year?
Replies: 101
Views: 39144

Re: 2014 Dark Horse Trifecta Year?

Can't say I'm the most familiar with tri-alpha's plans given their lack of public information. But assuming they are still talking about some type of field reversed configuration, there will be confinement magnets that are basically right next to where the fusion is happening; same general idea as I...