Talk-Polywell.org

How does this compare to Polywell? My science background is not in this field, and rather ... out of date.

It's a stellerator - precursor to the tokamak. A tube of plasma with a much smaller tube radius and large torroidal radius. Lots of interesting physics.

drmike wrote:Lots of interesting physics.

That's what they all say. :-)

I was searching the internet on fusion and was suprised to discover that the Riggatron is still being researched to this day. It's now called the Compact Ignition Torus.

Research is always good. The more people we have working on different problems, the easier it is to combine the answers to find solutions to new problems.

The main problem is that we can't model plasmas at all. There is no way to predict what will happen. So experiments are really important to get empirical formulas.

It worked for water flowing in pipes, and now all cities are built using the numbers found in the late 1800's. There's no perfect model for water (or sewage) flowing in a pipe, but the empirical formulas work really well.

Plasma is just a little bit more complicated than sewage.

Its toridial with a mobius twist.... no ?

http://images.google.com/images?q=Wende ... a=N&tab=wi

So is it intended to produce net energy in the future? If so, how far is it in our future? Now that I think of it, how many reputable programs are going on out there that seek to create net energy from fusion as a way to replace fossil fuels?
1. Polywell Fusion
2. …hmm…uh…
3. ….?

These guys mean serious business!

Nice progress with the Wendelstein 7-X stellarator:

Testing of the magnetic field in the Wendelstein 7-X fusion device was completed sooner than planned. The measurements, which were much anticipated at the Max Planck Institute for Plasma Physics in Greifswald, show: The superconducting magnetic coils, whose technical tests were completed only last week (see IPP-Info 6/15) are producing the required magnetic field. The magnetic cage for the fusion plasma, which has a temperature of many million degrees, has a configuration which is in line with the calculations of the physicists. This is an essential milestone in the operational preparations that are currently under way. Later this year, Wendelstein 7-X should produce its first plasma.

http://www.ipp.mpg.de/3897638/07_15

I think the Stellarator is advertised as having a higher plasma density potential than that of Tokamaks. As such research and eventual production machines could be smaller, which means cheaper and possibly more appropriate for the electrical grid. The same claims are made for the Polywell and other relatively compact designs.

Having said that, I think I read that this generation of this machine took ~ 20 years to build. How much of this was politics, budget problems, and waiting for computer simulations to guide them is unknown.

Dan Tbbets

D Tibbets wrote:Having said that, I think I read that this generation of this machine took ~ 20 years to build. How much of this was politics, budget problems, and waiting for computer simulations to guide them is unknown.

If we remove the computer simulations I would say that 18 years is a fair guess.....

The 7-X is a stellarator, a torus with 5 twists. It's like a tokamak, but the plasma path around the torus is the same length for all points in the plasma. This is supposed to help with drift and eliminates some modes of instability.

The problem is they are really tough to design and even harder to build. The 7-X is the biggest and best designed yet. I'm not sure it's even meant to do fusion, but really learn more about building and operating a big stellarator in a continuous fashion. If they are hitting the temperatures required and can do so for blocks of hours at a time then they can start building one to do fusion. I think the problem of making it radiation resistant along with the rest of the construction challenges was just an additional headache they didn't have the budget or time for.

Very cool machine.

With the generation of the first plasma the Wendelstein 7-X fusion device is scheduled to go into operation on time in December 2015 at the Max Planck Institute for Plasma Physics (IPP) in Greifswald/Germany. The experiments will begin with a plasma consisting of the noble gas helium. The Wendelstein 7-X fusion device is the world’s largest and most advanced device of the stellarator type. Its objective is to investigate the suitability of this type for a power plant.

Subject to the operating licence being granted, the first plasma has been scheduled for 10 December 2015. “We will start with a plasma of the noble gas helium and change, next year, to the actual object of investigation, a hydrogen plasma“, states Project Head Professor Thomas Klinger: “In helium the plasma state is easier to achieve. Moreover, we can use the helium plasmas to clean the surface of the plasma vessel.“ The first hydrogen plasma will follow at the end of January 2016.

It will be very interesting to hear how W 7-X performs with a plasma.

http://www.ipp.mpg.de/3985731/w7x_15_2

I have been waiting for this machine to be complete for the last 15 years and finally, after 10 years of delay, is ready.

In 6 month time we will have lot of new reports on arxiv or lot of blaming and "finger pointing" going on at IPP.... If it does not perform as expected it will be a big personal delusion.