

US Navy awards funds for Polywell Fusion reactor experiment  - cwan
http://www.classicalvalues.com/archives/2009/10/wb8_contract_pr.html

======
camccann
For those not familiar with the Polywell design, it's a refinement of the
slightly more well-known Farnsworth Fusor. The fusor design is surprisingly
simple; small versions can be (and have been) constructed by hobbyists that
will successfully fuse hydrogen.

Unfortunately, the fusor has serious drawbacks--probably unsurmountable--that
make it impossible to get net energy output from the device, though it does
function competently as a portable neutron source.

The fusor design (as well as the polywell, in a modified fashion) differs from
conventional approaches to fusion, in that it uses concentric, spherical mesh
electrodes in a vacuum chamber with an enormous voltage between them.
Positively-charged ions are accelerated toward the center of the device by the
interior, negative electrode; any that pass through are repelled by the outer
electrode, so ions oscillate through the center of the device at very high
speeds until either striking and fusing with another ion or impacting an
electrode.

The more sophisticated polywell design uses a form of magnetic confinement to
trap electrons in the center of the device, creating a "virtual electrode" and
reducing losses from ions impacting electrodes. Unlike the fusor, there don't
seem to thus far be any significant theoretical barriers to net energy gain
from the polywell design. The main issue limiting further development of the
polywell concept has generally been a lack of attention and funding needed to
develop and engineer larger and more refined versions.

In short, this is excellent news.

~~~
electromagnetic
The other thing to note is that it's _small_. I believe WB6 was roughly the
size of your average CRT monitor.

The estimated cost for a full scale polywell is ~$100 million, less than
1/100th of ITER's estimated costs. It has the potential for commercial fusion
energy by 2020, not by 2050 like ITER. This, of course, is assuming the larger
scale Polywell designs will break even with WB8.

~~~
camccann
Thank you, I forgot to mention that. Assuming the polywell design works as
hoped, it is likely to be much smaller and cheaper for the same output than
other fusion reactor designs.

I've been interested for a while in the potential of IEC-type reactors, so I'm
really looking forward to the results of this new work.

------
eggoa
I first read about this in an article in Analog Science Fiction magazine. The
technology sounded cool but the venue of publication seemed inauspicious. . .
I really hope this produces something.

~~~
sp332
Robert Bussard has more detail in his Google Tech Talk:
[http://video.google.com/videoplay?docid=1996321846673788606&...](http://video.google.com/videoplay?docid=1996321846673788606&ei=dS3JSuLbAsSXlAfQnsHcBg)

~~~
stcredzero
Unfortunately, $10M is 1/20th what Robert Bussard wanted to try and build a
break-even demo reactor.

~~~
berntb
According to Nebel, the research leader, the present funding is enough to know
if it will work. Check this, from May.

[http://nextbigfuture.com/2009/05/dr-richard-nebel-we-will-
kn...](http://nextbigfuture.com/2009/05/dr-richard-nebel-we-will-know-if-
iec.html)

Edit: Which was linked from the article. :-) Sigh, I read the recent news last
night somewhere else and didn't check this.

