[Dean's World] Dave Price: Polywell Fusion Power Update

[notify at powerblogs.com]

Posted by Dave Price:
Polywell Fusion Power Update
http://www.deanesmay.com/posts/1179866647.shtml


   Since [1]previously posting on the Polywell fusion project after
   seeing [2]Bussardâs Google presentation on his [3]Polywell fusion
   reactor design, Iâve been trying to read all I can on the subject, and
   have been surprised how few unaddressed technical objections seem to
   exist. At first I assumed this technology was a very long shot, as
   such prospective technologies generally are, but now Iâm starting to
   wonder.
   This is apparently not particularly novel physics or engineering;
   inertial electromagnetic confinement fusion has been well-understood
   since [4]Farnsworthâs work in the 1960s, but was abandoned (at least
   for power generation) because it appeared electrons hitting the grid
   and [5]bremsstrahlung losses would always prevent IEC fusors from
   generating net power. Bussardâs insight and achievement was the
   development of a âgridlessâ device wherein the physical grid is
   replaced by magnetic fields, allowing electrons to recirculate 100,000
   times rather than being absorbed by the grid. Additionally, according
   to Ligon the bremsstrahlung problem is solved by the fact that the
   electrons only maxwellianize at the âtopâ of the well as they bunch
   up, which serves to greatly reduce those losses. Hereâs the [6]best
   overview of the technology Iâve run across.
   [7]Dr. Bussard was interviewed on the radio on a space program the
   other day, and I got a chance to talk to him and his colleague Tom
   Ligon briefly (thanks [8]M Simon for posting the heads-up in the
   [9]Yahoo IEC Fusion group). Bussard told me his focus now is to raise
   the $5 million or so necessary to build an improved WB-7 machine,
   which should have even better containment than WB-6 and produce enough
   fusion data that other experts can be assembled to examine the device
   and pronounce the concept sound, after which enough publicity should
   arise that the necessary $100M - $200M funding for a full-scale,
   net-power model becomes feasible (for comparison, the [10]ITER machine
   will cost more than $10 billion and is only a prototype).
   In a possibly noteworthy development, [11]John Carmack, programmer of
   Doom and Quake fame and [12]rocketry enthusiast, has become aware of
   Bussardâs work and [13]expressed some interest in building a Polywell
   fusor. He probably has the resources to build a working Polywell
   prototype on his own, but as he has said he is at the bottom of a very
   steep learning curve.
   One of the most exciting aspects of the technology is the potential to
   generate electricity directly (rather than heating water and running
   it through a turbine) by converting alpha radiation created by an
   [14]aneutronic fusion reaction, most likely the âp-11bâ reaction
   whereby boron-11 is fused with hydrogen, yielding helium-4 and the
   aforementioned alphas. Of course, the energy levels for that reaction
   are much higher, so the first commercial Polywell reactors would
   almost certainly be the usual boring thermal designs powered by
   deuterium/tritium fusion, but an aneutronic direct-power device has
   huge implications, especially for space travel.
   Accepting Bussard's claims that his WB-6 fusion device did produce
   neutrons and that the energy gain will scale as the 5th power of the
   radius of the device, the stumbling block appears to be the lack of a
   functioning device (WB-6 was destroyed in one of the last test runs)
   which the scientific community can study and validate. Once again,
   [15]Bussardâs company is soliciting donations to raise the ~$5 to
   build the WB-7 device.

References

   1. http://www.deanesmay.com/posts/1178563200.shtml
   2. http://video.google.com/videoplay?docid=1996321846673788606
   3. http://en.wikipedia.org/wiki/Polywell
   4. http://en.wikipedia.org/wiki/Fusor
   5. http://en.wikipedia.org/wiki/Bremsstrahlung
   6. http://www.science.edu/TechoftheYear/TechoftheYear.htm
   7. http://en.wikipedia.org/wiki/Bussard
   8. http://www.powerandcontrol.blogspot.com/
   9. http://tech.groups.yahoo.com/group/IEC_Fusion/
  10. http://en.wikipedia.org/wiki/ITER
  11. http://en.wikipedia.org/wiki/John_Carmack
  12. http://armadilloaerospace.com/n.x/Armadillo/Home
  13. http://fusor.net/board/view.php?bn=fusor_introductions&key=1179183175
  14. http://en.wikipedia.org/wiki/Aneutronic_fusion
  15. http://www.emc2fusion.org/