Editing Polywell

[[Image:Polywell WB-6 complete.jpg|thumb|Polywell WB-6 model assembled]]

A '''polywell''' device is a type of [[fusion reactor]] that was developed by [[Robert Bussard]] under a [[United States Navy|US Navy]] research contract. It traps [[electrons]] inside its hollow center by [[inertial electrostatic confinement]]. Then, positively charged [[ions]] can be injected for the purpose of achieving [[magnetic confinement fusion]]. The polywell device can trace its development from the ideas behind the [[Farnsworth-Hirsch Fusor]]. Bussard theorized that this device could potentially generate net energy production and thus become a source for [[electric power]].

The polywell consists of several positively charged [[electromagnet]] coils that are arranged in a [[polyhedron]]. This charged magnetic polyhedron is called a MaGrid. Electrons are introduced from outside and are accelerated into the MaGrid due to the electric field. Within the MaGrid, magnetic fields confine most of the electrons and those that escape are retained by the electric field. This configuration traps the electrons in the middle of the device focusing them near the center which produces a virtual cathode (negative [[electric potential]]). Ions are introduced and the virtual cathode is used to accelerate and confine them so they will fuse, creating fusion power. Robert Bussard developed it as an improvement of the Elmore-Tuck-Watson fusor which was based on the Farnsworth-Hirsch fusor.

The name polywell is a [[portmanteau]] of "[[polyhedron]]" and "[[potential well]]."

== Design ==
=== Problems with Farnsworth-Hirsch fusors ===

A traditional Farnsworth-Hirsch [[fusor]] consists of a [[vacuum]] chamber containing a positively charged outer grid and a negatively charged inner grid; essentially a large [[vacuum tube]] with spherical grids. Fusible atomic [[Atomic nucleus|nuclei]] are injected as [[ion]]s into the system and accelerated toward the inner grid. Most of the time, the ions pass through the grid and enter the core where they either impact or miss other ions. On a miss (or non-fusing impact), the nuclei move outwards and pass through the inner grid which decelerates them and then reaccelerates them inward wherein they return through the core. Occasionally, given long enough, nuclei strike either the grid or another high-energy nucleus. Most strikes with other nuclei do not result in fusion, but occasionally fusion results.

A benefit with the Farnsworth-Hirsch fusor is that without the motion of electrons and magnetic fields, there are no [[synchrotron radiation|synchrotron losses]] and (if the grid is kept cool to reduce [[thermionic emission]]) low levels of [[bremsstrahlung]].<ref>{{cite web
  | title = Design Of An Actively Cooled Grid System To Improve Efficiency In Inertial Electrostatic Confinement Fusion Reactors
  | author = Andrew Seltzman
  | date = 2008-05-30
  | work = www.rtftechnologies.org
  | url = http://www.rtftechnologies.org/Design/Assets/device-images/fusor-mark3/files/seltzman_andrew_h_200805_phys.pdf
  | accessdate = 2009-08-14
}}</ref>

The fundamental problem with this traditional system is with the grid itself. Far too often, nuclei strike the grid. This damages the grid, wastes the energy that went into ionizing and accelerating the particle, and most critically, heats the grid. Even if the former problems were not critical, having a fine mesh grid in a reactor producing enough power to be used as a power plant would almost certainly mean that it would be rapidly vaporized.

=== Problems with Elmore-Tuck-Watson fusors ===

An Elmore-Tuck-Watson [[fusor]] inverts the charges on the grids. It consists of a [[vacuum]] chamber containing a negatively charged outer grid (which may be the chamber) and a positively charged inner grid. Electrons are injected into the system and accelerated toward the inner grid. Most of the time, the electrons pass through the grid, through the core, and through the inner grid again, which then decelerates them and reaccelerates them inward wherein they return through the core. As they pass repeatedly through the core, they generate a negatively charged zone, a potential well, which is called a virtual cathode. Fusible atomic [[Atomic nucleus|nuclei]] are then introduced inside the positive grid where they are ionized. The virtual cathode accelerates the ions toward the center where they oscillate within the potential well. Since the ions never (in theory) reach the grid, they never lose their energy to such impacts and continue to oscillate through the core. Given enough oscillations, the ions strike other high-energy ions and fuse.
The fundamental problem with this variation system is still the grid itself. Far too often the electrons strike the grid. Thus the Elmore-Tuck-Watson fusor has the same basic problems as the Farnsworth-Hirsch fusor.

=== The polywell approach ===

Like the Elmore-Tuck-Watson (ETW) fusor, the polywell confines positive ions through their attraction to the negative potential well which is created by the electrons that are held inside a positively charged grid. However, to avoid the losses related to the electrons striking the grid, the Polywell uses magnetic fields to shield the grid. The magnetic fields are configured in a way that adds to the confinement of the electrons so that there are many more electrons inside the core than outside.

The reactor volume is defined by the coils producing the magnetic field. The coils are held at a positive potential relative to the surrounding outer grid which may or may not be the walls of the vacuum chamber. This provides the same function as the positive and negative grids in the ETW fusor which is to restrain and return any electrons that escape the core. The charged coils are known as MaGrids, from "Magnetic Grids".{{Citation needed|date=July 2010}}

Ions are added at a density nearly equal to that of the electrons to produce a quasi-neutral [[Plasma (physics)|plasma]], but a slight excess of electrons maintains the negative potential well.<ref name="patent1992">{{US patent reference|
number=5,160,695|
y=1992|m=11|d=03|
inventor=Robert W. Bussard|
title= Method and apparatus for creating and controlling nuclear fusion reactions}}</ref>
While this concept differs from the original ETW fusor in that it uses magnetic fields, it also differs from traditional magnetic confinement because the fields do not need to confine ions — only electrons, which is much easier.<ref name="quasi">{{cite journal
 | last = Krall | first = Nicholas A.
 | coauthors = Bussard, Robert W.
 | title = Forming and maintaining a potential well in a quasispherical magnetic trap
 | journal = Physics of Plasmas
 | volume = 2
 | issue = 1
 | year = 1995
 | pages = 146–158
 | doi = 10.1063/1.871103
 | id = {{ISSN|1070664x}}
/Forming_and_maintaining_a_potential_well_Krall_Bussard_1995.pdf
}}</ref><ref name="tech">{{cite journal
 | last = Bussard | first = Robert W.
 | title = Some physics considerations of magnetic inertial-electrostatic confinement ;A new concept for spherical converging-flow fusion
 | journal = Fusion Technology
 | volume = 19
 | issue = 2
 | year = 1991
 | pages = 273–293
 | id = {{ISSN|07481896}}
/Some_physical_Considerations_Bussard_FusionTechnology_1991.pdf
}}</ref><ref name="tech2">{{cite journal
 | last = Krall | first = Nicholas A.
 | title = The Polywell ;A spherically convergent ion focus concept
 | journal = Fusion Technology
 | volume = 22
 | issue = 1
 | year = 1992
 | pages = 42–49
 | id = {{ISSN|07481896}}
/Polywell_spherically_convergent_ion_focus_concept_Fusion_Technology_Krall_1992.pdf
}}</ref>

In most experiments to date, the MaGrid arrangement has been approximated by a symmetrical arrangement of discrete, circular coils, all pointing toward (or all away from) the center. The magnetic field vanishes at the center by symmetry, and the magnetic flux that enters the volume through the coils leaves it again through the spaces between the coils. This configuration confines electrons to the central volume by a [[magnetic mirror]] with a large field ratio or, under some conditions, a magnetic [[cusp]]. Bussard claimed<ref name="patent1989">{{US patent reference|
number=4,826,646|
y=1989|m=05|d=02|
inventor=Robert W. Bussard|
title= Method and apparatus for controlling charged particles}}</ref>
that the MaGrid arrangement of the magnetic field has only point cusps but acknowledged that the circular coils produce line-like cusps at the closest approaches of the coils.

==== Polywell results ====
Despite initial difficulties in spherical electron confinement, at the time of the 2005 research project's termination, Bussard had reported a fusion rate of 10<sup>9</sup> per second running D-D fusion reactions at only 12.5 kV (based on [[neutron detection|detecting]] a total of nine neutrons in five tests,<ref name="IAC2006">[http://www.askmar.com/ConferenceNotes/2006-9%20IAC%20Paper.pdf  "The Advent of Clean Nuclear Fusion: Super-performance Space Power and Propulsion"], Robert W. Bussard, Ph.D., 57th International Astronautical Congress, October 2–6, 2006</ref><ref name="lab_notes">''Final Successful Tests of WB-6'', EMC2 Report, currently (July 2008) not publicly available<!-- {{
cite web
  | title = Final Successful Tests of WB-6
  | author = EMC2 Report
  | url = http://ecow.engr.wisc.edu/cgi-bin/getbig/ne/527/anderson/notes/bussard_wb6rpt080604fnl0107.pdf
  | accessdate = 2007-11-08
}} --></ref> giving a wide [[confidence interval]]). He claimed that the fusion rate achieved by WB-6 is roughly 100,000 times greater than that Farnsworth managed to achieve at similar well depth and drive conditions.<ref name="fusor.net">{{
cite web
  | title = Inertial Electrostatic Fusion systems can now be built
  | author = Robert W. Bussard
  | date = 2006-03-29
  | work = fusor.net forums
  | url = http://www.fusor.net/board/view.php?site=fusor&bn=fusor_announce&key=1143684406
  | accessdate = 2006-12-03
}}</ref><ref name="randi">{{
cite web
  | title = Fusion, eh?
  | author = SirPhilip (posting an e-mail from "RW Bussard")
  | date = 2006-06-23
  | work = [[James Randi Educational Foundation]] forums
  | url = http://forums.randi.org/showthread.php?t=58665#27
  | accessdate = 2006-12-03
}}</ref> By comparison, researchers at the [[University of Wisconsin, Madison]] have claimed a neutron rate of up to 5×10<sup>9</sup> per second at voltages of 120 kV with an electrostatic fusor without magnetic fields.<ref>[http://iec.neep.wisc.edu/results.php UW–IEC Project]</ref>

Bussard claimed that, assuming [[superconductor]]s are used for the coils, the only significant energy loss channel is through electron losses proportional to the surface area. He also claimed that the density would scale with the square of the field (constant [[Beta (plasma physics)|beta]] conditions), and the maximum attainable magnetic field would scale with the radius (technological constraints). Under those assumptions, the fusion power produced would scale with [[Power law|the seventh power of]] the radius, and the energy gain would scale with the fifth power. While Bussard did not publicly document the physical reasoning underlying this estimate,<ref>
Possibly he assumed that the ion energy distribution is fixed, that the magnetic field scales with the linear size, and that the ion pressure (proportional to density) scales with the [[magnetic pressure]] (proportional to ''B''²). The ''R''<sup>7</sup> scaling results from multiplying the fusion power density (proportional to density squared, or ''B''<sup>4</sup>) with the volume (proportional to''R''³). On the other hand, if it is important to maintain the ratio of the [[Debye length]] or the [[gyroradius]] to the machine size, then the magnetic field strength would have to scale ''inversely'' with the radius, so that the total power output would actually be lower in a larger machine.</ref> if true, it would enable a model only ten times larger to be useful as a fusion power plant.<ref name="IAC2006"/>

== Comparison to conventional confinement concepts ==

The polywell is related to various other plasma confinement concepts, but differs markedly from all of them. It is most closely related to the [[fusor]], which, like the polywell, confines ions by an inwardly directed electric field and requires a grid of solid-state electrodes within the plasma vessel. Both concepts intend to operate with a highly non-thermal, ideally mono-energetic, distribution of ion energies<ref name="tech" />. If the ion energies can be held near the optimum value, the fusion rate for a given plasma pressure can be a few times higher than the maximum rate possible for ions with a thermal distribution. On the other hand, collisions and collective instabilities have a tendency to restore a thermal distribution, so that it generally costs power to maintain a mono-energetic distribution.

The polywell differs from the fusor in that the electrons are magnetically confined, so that it is also related to [[magnetic confinement fusion]], most closely to [[Magnetic confinement fusion#Magnetic mirrors|magnetic mirrors]]. In common with magnetic mirrors is the field minimum in the central region, the confinement (in part) by the [[Magnetic mirror|mirror effect]], and (at least to some extent) a non-thermal distribution of the electron energies. In some mirror configurations, the field in the center is a minimum in every direction, as it is in the central region of a polywell. The magnetic field in such a case is said to have "good curvature" because a certain class of fluctuations are stable in a plasma contained by such a field. In contrast to mirror machines, the polywell does not just have a minimum in the field strength in the center, the field vanishes entirely there. Also the polywell does not have a magnetic axis, but rather a polyhedral symmetry.

The most actively developed plasma confinement concept at this time is the [[tokamak]], the concept behind [[ITER]]. A net power fusion reactor based on the tokamak concept, if possible, would certainly be a large and complex machine. The advocates of the polywell predict that a polywell reactor of similar power would be much smaller and simpler. The tokamak has a toroidal geometry with nested flux surfaces, so that both ions and electrons can only be lost by transport across magnetic field lines (primarily as a result of instabilities with very short wavelengths). The confinement of particles in a polywell is more complex, involving both magnetic and electric fields, transport of particles both across and along magnetic field lines, and different processes for the ions than for the electrons.

== Possibility of  net power ==

All of Bussard's Polywell experiments, were based on  deuterium-deuterium (<sup>2</sup>H+<Sup>2</sup>H ) reactions.  This was because it has a high reaction cross section, at a  low temperature, relative to other fuels . Deuterium tritium (<sup>2</sup>H+<Sup>3</sup>H )  reactions have a higher cross section at a lower temperature, but since tritium is not naturally occurring on Earth, it would have been too costly to use,  for polywell experiments<ref name="google"/>.   However,  tritium is produced in  <sup>2</sup>H+<Sup>2</sup>H reactions, and could be fed back into the polywell as fuel, giving the highest possibility of net power.{{citation needed|date=August 2010}}  Bussard theorized,  that a Polywell reactor, with a Radius of 1.5 meters,  would produce economically viable net power, using  (<sup>2</sup>H+<Sup>2</sup>H ) reactions.  The downside to both <sup>2</sup>H+<Sup>2</sup>H  and <sup>2</sup>H+<Sup>3</sup>H  reactions, is that they produce fast neutron radiation, which did not meet Bussard's goal, for radiation free fusion power.<ref name="google"/>

Bussard theorized that this device could produce net power with [[Aneutronic fusion|boron-11 and proton fuel]]. This was disputed by [[Massachusetts Institute of Technology|MIT]] doctoral student, Todd Rider, who calculated that, even with optimistic assumptions, [[bremsstrahlung]] losses with this fuel will exceed fusion power production by at least 20%.<ref>[http://dspace.mit.edu/bitstream/1721.1/11412/1/33227017.pdf ''Fundamental limitations on fusion systems not in equilibrium'', pp. 161-2]</ref> In contrast, Bussard's calculation indicates that the bremsstrahlung losses could be as little as one twelfth of the fusion power production, so that a net power reactor cannot be ruled out on this basis.<ref name="looses">[http://www.askmar.com/Fusion_files/EMC2%20Reports/EMC2-0891-04%201991%20Bremmstrahlung%20Radiation%20Losses.pdf  "Bremsstrahlung Radiation Losses in Polywell Systems"], R.W. Bussard and K.E. King, EMC2, Technical Report EMC2-0891-04, July, 1991. Table 2, p. 6.</ref>

According to Bussard the high speed and therefore low cross section for [[Coulomb collision]]s of the ions in the core makes thermalizing collisions very unlikely, while the low speed at the rim means that thermalization there has almost no impact on ion velocity in the core.<ref name="IAC2006"/>

Another paper on the feasibility of IEC fusion, using the full bounce-averaged [[Fokker-Planck equation]] operator, concluded that IEC systems could produce large fusion energy gain factors ([[Fusion energy gain factor|Q values]]). However, a deuterium-tritium reaction was necessary to minimize operating potential and Bremsstrahlung losses in order to reach large Q values.<ref name="Chacon">[http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PHPAEN000007000011004547000001&idtype=cvips&gifs=yes "Energy gain calculations in Penning fusion systems using a bounce-averaged Fokker–Planck model"], Chacon, Barnes, Miley and Knoll, Phys. Plasmas 7, 4547 (2000); DOI:10.1063/1.1310199</ref>

== History ==
[[Image:Polywell WB-2.jpg|thumb|WB-2]]
[[Image:Polywell WB-3.jpg|thumb|WB-3]]
[[Image:Polywell WB-6 coils.jpg|thumb|WB-6 during assembly with coils showing]]

In the late 1960s there were several investigations of polyhedral magnetic fields as a possibility to confine a fusion plasma.<ref>R.Keller and I.R.Jones, "Confinement d'un Plasma par un Systemem Polyedrique a' Courant Alternatif", ''Z. Naturforschung'', Vol. 21 n, pp. 1085-1089 (1966), as cited by R.W.Bussard in U.S.Patent 4,826,646, "Method and apparatus for controlling charged particles", issued May 2, 1989, p.12.</ref><ref>"Spherical Multipole Magnets for Plasma Research", Sadowsky, M., ''Rev.Sci.Instrum.'' 40 (1969) 1545</ref> The first proposal to combine this magnetic configuration with an electrostatic potential well in order to improve electron confinement was made by [[Lavrentiev, Oleg|Lavrent’ev]] in 1975.<ref>"Electrostatic and Electromagnetic High-Temperature Plasma Traps", O.A.Lavrent’ev, Conference Proceedings, Electrostatic and Electromagnetic Confinement of Plasmas and the Phenomenology of Relativistic Electron Beams, ''Ann. N.Y. Acad. Sci.'' 251, (1975) 152-178, as cited by Todd H. Rider in "A general critique of inertial-electrostatic confinement fusion systems", ''Phys. Plasmas'' 2 (6), June 1995. Rider specifically stated that "Bussard has revived an idea originally suggested
by Lavrent’ev".</ref>

The idea was picked up by Robert Bussard in 1983, a link acknowledged in the references cited by his 1989 patent application<ref name="patent1989" />, though in 2006 he appears to claim to have re-discovered the idea independently.<ref name="quick">{{cite web
| url = http://www.fusor.net/board/getfile.php?bn=fusor_announce&att_id=2494
| title = A quick history of the EMC2 Polywell IEF concept
| author = Posted to the web by Robert W. Bussard
| accessdate = 2006-12-03
| year = 2006
| month = February
| format = [[Microsoft Word]] document
| publisher = Energy/Matter Conversion Corporation
}}</ref>  Research was funded by the [[United States Department of Defense|Department of Defense]] beginning in 1987, and the [[United States Navy]] began providing low-level funding to the project in 1992.<ref name="clean">{{cite web
| url = http://www.fusor.net/board/getfile.php?bn=fusor_announce&att_id=2493
| title = Inertial electrostatic fusion (IEF): A clean energy future
| author = Posted to the web by Robert W. Bussard
| accessdate = 2006-12-03
| format = [[Microsoft Word]] document
| publisher = Energy/Matter Conversion Corporation
}}</ref>  Bussard, who had formerly been an advocate for [[Tokamak]] research, became the premiere advocate for and researcher on the concept, so that the idea is now indelibly associated with his name. In 1995 he sent a letter to the [[United States Congress]] stating that he had only supported Tokamaks in order to get fusion research sponsored by the government, but he now believed that there are better alternatives to Tokamaks.

Polywell models were produced through an iterative process, ranging from WB-1 through WB-6 (with WB-7 and 8 planned, but not constructed by Bussard's team; see FY2008-9 sections below for details on current WB-7 and WB-8 models). Early designs consisted of tightly welded stainless steel cubes of electromagnets, wound on square-cross section spools. These designs suffered from "funny cusp" losses at the joints between magnets, and from the magnetic field clipping the corners of the spools. The losses into the metal severely hurt their performance, leading to lower electron trapping performance than predicted. Later designs (starting with WB-6) began spacing electromagnets apart instead of touching, and changed to circular cross sections instead of square, reducing the metal surface area unprotected by magnetic fields. These changes dramatically improved system performance, leading to a great deal of electron recirculation and the confinement of electrons into a progressively tighter core. Until 2005 all of the reactors have been 6-magnet designs built as a cube (or more specifically as a truncated cube). Bussard's WB-8 was planned to be a higher-order polyhedron, with 12 electromagnets (this design was not used in the actual WB-8 machine).

Funding became tighter and tighter. According to Bussard, "The funds were clearly needed for the more important [[2003 Invasion of Iraq|War in Iraq]]."<ref name="randi"/> An extra $900k of [[Office of Naval Research]] funding allowed the program to continue long enough to reach WB-6 testing in November 2005. The last-produced model, WB-6, produced a fusion rate of 10<sup>9</sup> per second. Drive voltage on the WB-6 tests was about 12.5 kV, with a resulting potential well depth of about 10 kV, thus deuterons arriving in the center of the machine will have a kinetic energy of 10 keV. By comparison, a Fusor running deuterium fusion at 10 kV would produce a fusion rate difficult to detect at all. Hirsch reported a fusion rate this high only by driving his machine to 150 kV and by using deuterium-tritium fusion (a much easier reaction). While the pulses of operation in WB-6 were sub-milliseconds, Bussard felt the conditions should represent steady state as far as the physics are concerned. Most critically, the models of the system indicate that a full-sized model, costing approximately $150–200M (depending on the fuel), should be an effective power plant, producing notably more energy than it consumes. A last-minute test of WB-6 ended prematurely when the insulation on one of the hand-wound [[electromagnet]]s burned through, destroying the device. With no more funding during 2006 and partly 2007, the project's military-owned equipment was transferred across town to [[SpaceDev]], which also hired three of the team's researchers.<ref name="randi"/>

After the transfer, Bussard tried to attract new investors, giving talks trying to raise interest in his design. A talk at [[Google]] headquarters had the title, "Should Google Go Nuclear?"<ref name="google">{{cite web
| url = http://video.google.com/videoplay?docid=1996321846673788606
| title = Should Google Go Nuclear? Clean, cheap, nuclear power (no, really)
| author = Dr. Robert Bussard (lecturer)
| accessdate = 2006-12-03
| date = 2006-11-09
| format = [[Adobe Flash|Flash]] video
| work = Google Tech Talks
| publisher = [[Google]]
}}</ref>  An informal overview of the last decade of work was presented at the 57th International Astronautical Congress in October 2006.<ref name="IAC2006"/>

Dr. Bussard formed EMC2 Fusion Development Corporation, [http://www.emc2fusion.org] a [[non-profit organization]], to seek funding for continuation of the project.

== Recent US Navy funded work ==

With the success of WB-6, Bussard believed that the system had demonstrated itself to the degree that no intermediate-scale models would be needed, and noted, "We are probably the only people on the planet who know how to make a real net power clean fusion system"<ref name="fusor.net"/> He proposed to rebuild WB-6 more robustly to verify its performance. After conducting and publishing the results of dozens of repeatable tests, he planned to convene a conference of experts in the field in an attempt to get them behind his design. Assuming his design had been backed, the project would have immediately moved toward a full-scale demo plant. The first step in that plan was to design and build two more small scale designs (WB-7 and WB-8) to determine which full scale polyhedral potential well would be best. He wrote “The only small scale machine work remaining, which can yet give further improvements in performance, is test of one or two WB-6-scale devices but with “square“ or polygonal coils aligned approximately (but slightly offset on the main faces) along the edges of the vertices of the polyhedron. If this is built around a truncated dodecahedron, near-optimum performance is expected; about 3-5 times better than WB-6.” <ref name="IAC2006"/>

Bussard noted that, "Thus, we have the ability to do away with oil (and other fossil fuels) but it will take 4-6&nbsp;years and ca. $100-200M to build the full-scale plant and demonstrate it."<ref name="fusor.net"/>

Bussard said "Somebody will build it; and when it's built, it will work; and when it works people will begin to use it, and it will begin to displace all other forms of energy."<ref>{{cite episode
 | title        = [http://www.thespaceshow.com/ The Space Show]
 | credits      = Hosted by Dr. David Livingston
 | airdate      = 2007-05-08
 | number       = [http://archived.thespaceshow.com/detail.asp?q=709 709] with guests Dr. Robert W Bussard, Thomas A Ligon
 | minutes      =
}}</ref>

=== Fiscal year (FY) 2008 work ===

In August 2007, EMC2 received a $1.8M U.S. Navy research contract to continue the reactor development.<ref name="New Energy and Fuel">{{cite web| url = http://newenergyandfuel.com/http://newenergyandfuel/com/2007/08/23/funding-continues-for-bussards-fusion-reactor/| title = Funding Continues for Bussard's Fusion Reactor| date = 2007-08-27| publisher = New Energy and Fuel}} Note that this source is a blog and not necessarily reliable.</ref> Prior to Bussard's death in October, 2007,<ref name="defencenews">{{cite web| url = http://www.defensenews.com/story.php?F=3139619&C=america| title = Fusion Researcher Bussard Dies at 79| author = William Matthews| accessdate = 2007-11-06| date = 2007-11-06| format = webpage| work = Online article| publisher = Defencenews.com}}</ref>  Dolly Gray, who co-founded EMC2 with Bussard in 1985, and served as its president and CEO, helped assemble the small team of scientists in [[Santa Fe, New Mexico|Santa Fe]] to carry on his work. The group is led by Richard (Rick) Nebel and includes Jaeyoung Park; (both Nebel and Park are physicists on leave from the Los Alamos National Laboratory ([[LANL]])); Mike Wray, the physicist who ran the key 2005 tests; and Kevin Wray, who is the computer specialist for the operation.

What is now called WB-7, the more robust version of the WB-6 fusion device, was constructed at a machine shop in San Diego and shipped to Santa Fe to the EMC2 testing facility. The device, like previous ones, was designed by engineer Mike Skillicorn. This WB-7 however was not the “square” coil suggested by Dr. Bussard.

WB-7, achieved "1st plasma" in early January, 2008.<ref name="MSNBC - CosmicLog">{{cite web| url = http://cosmiclog.msnbc.msn.com/archive/2008/01/09/566532.aspx| title = Strange Science Takes Time| date = 2008-01-09| publisher = MSNBC}}</ref><ref name="MSNBC - CosmicLog2">{{cite web| url = http://cosmiclog.msnbc.msn.com/archive/2008/06/12/1136887.aspx| title = Fusion Quest Goes Forward| date = 2008-06-12| publisher = MSNBC}}</ref>

No specific information has been published at this moment, due to a publishing embargo on research data maintained by US Navy.<ref>There is this clause in the [https://www.neco.navy.mil/upload/N68936/N6893609R0024RFP.pdf "SOLICITATION, OFFER AND AWARD"] for the "plasma wiffleball development project", [https://www.fbo.gov/index?s=opportunity&mode=form&id=754cf58a3fd1b02abfe8521ff4f488a7&tab=core&_cview=1&cck=1&au=&ck= awarded] on March 3, 2009, to Matter Conversion Corporation:
<blockquote>
5252.204-9504 DISCLOSURE OF CONTRACT INFORMATION (NAVAIR) (JAN 2007)
(a) The Contractor shall not release to anyone outside the Contractor’s organization any unclassified information
(e.g., announcement of contract award), regardless of medium (e.g., film, tape, document), pertaining to any part of
this contract or any program related to this contract, unless the Contracting Officer has given prior written approval.
(b) Requests for approval shall identify the specific information to be released, the medium to be used, and the
purpose for the release. The Contractor shall submit its request to the Contracting Officer at least ten (10) days
before the proposed date for release.
(c) The Contractor agrees to include a similar requirement in each subcontract under this contract. Subcontractors
shall submit requests for authorization to release through the prime contractor to the Contracting Officer.
</blockquote></ref> The previous project, led by the late Dr. Bussard, [[Robert Bussard#Appeal for funding|had been under an embargo for 11&nbsp;years]] between 1994 and 2005 when that series of contracts with the US Navy ended.

In August 2008, the team finished the first phase of their experiment and were waiting for the peer review of their results and a verdict from their federal funders on whether the experiment should proceed to the next phase. Dr. Nebel has said "we have had some success", referring to the team's effort to reproduce the promising results obtained by Dr. Bussard. "It's kind of a mix", Dr. Nebel reported. But he stated that the team has "a plan to go forward." "We're generally happy with what we've been getting out of it, and we've learned a tremendous amount" he also said.<ref>{{cite web| url = http://cosmiclog.msnbc.msn.com/archive/2008/08/28/1301440.aspx?CommentPosted=true| title = Fusion effort in Flux| author = Posted to the web by Alan Boyle| accessdate = 2008-09-08| year = 2008| month = September| format = [[HTML]] document| publisher = MSNBC}}</ref>

<gallery></gallery>

=== FY 2009 work ===

In September 2008 the [[Naval Air Warfare Center]], Weapons Division, [[Naval Air Weapons Station China Lake|China Lake, CA]] publicly pre-solicited a contract for research on an Electrostatic "[[Wiffle Ball]]" Fusion Device<ref>{{cite web
| url = https://www.fbo.gov/?tab=core&s=opportunity&mode=form&id=3ea62e93d6aa0220c884d316af43c00b
| title = A--Fusion Device Research, Solicitation Number: N6893608T0283
| accessdate = 2008-10-02
| year = 2008
| month = September
| format = [[HTML]] document
| publisher = Federal Business Opportunities
}}</ref>. the pre-solicitation was targeted toward EMC2 as preferred supplier.

In October 2008 the US Navy publicly pre-solicited two more contracts<ref>{{cite web
| url = https://www.fbo.gov/?tab=core&s=opportunity&mode=form&id=80e8b7c1181e3e54d92a8d23e3eec700
| title = A--Polywell Fusion Device Research, Solicitation Number: N6893609T0011
| accessdate = 2008-11-07
| year = 2008
| month = October
| format = [[HTML]] document
| publisher = Federal Business Opportunities
}}</ref><ref>{{cite web
| url = https://www.fbo.gov/?tab=core&s=opportunity&mode=form&id=8e59e11465cc26d4079ac9201008f960
| title = A--Spatially Resolved Plasma Densities/Particle Energies, Solicitation Number: N6893609T0019
| accessdate = 2008-11-07
| year = 2008
| month = October
| format = [[HTML]] document
| publisher = Federal Business Opportunities
}}</ref> also targeted toward EMC2 as preferred supplier. These two tasks were to develop better instrumentation and to develop an ion injection gun. Rick Nebel commented "This isn't a big deal. This is small, interim funding. It's called staying alive until they make a decision."<ref>{{cite web
| url = http://www.talk-polywell.org/bb/viewtopic.php?p=11400&highlight=#11400
| title = Found this during google search on Polywell Fusion
| accessdate = 2008-11-07
| year = 2008
| month = October
| format = Discussion forum
| publisher = Talk-Polywell.org
}}</ref>  Other than Dr. Nebel's comments, there is no direct evidence that these pre-solicitations ever went to award.

In December 2008, following many months of review by the expert review panel of the submission of the final WB-7 results, Dr Richard Nebel commented that "There's nothing in there [the research] that suggests this will not work," but that "That's a very different statement from saying that it will work."

[[Stephen Chu]], [[Nobel Prize in Physics|Nobel laureate]] and {{as of|2009|lc=on}} [[United States Secretary of Energy]], answered a question about Polywell at a talk at [[Google]] in 2007, saying "So far, there's not enough information so [that] I can give an evaluation of the probability that it might work or not...But I'm trying to get more information."<ref>{{cite web
| url = http://cosmiclog.msnbc.msn.com/archive/2008/12/16/1718741.aspx
| title = Fusion we can believe in?
| accessdate = 2008-12-18
| year = 2008
| month = December
| format = Science subsite of MSNBC.com
| publisher = MSNBC.com
}}</ref>

In January 2009 the Naval Air Warfare Center pre-solicited another contract for "modification and testing of plasma wiffleball 7"<ref>{{cite web
| url = https://www.fbo.gov/index?s=opportunity&mode=form&tab=core&id=9cdc1fbbe6a740519220459e47f26249&_cview=0
| title = A--Plasma Wiffleball, Solicitation Number: N6893609R0024
| accessdate = 2009-01-26
| year = 2009
| month = January
| format = [[HTML]] document
| publisher = Federal Business Opportunities
}}</ref> which appears to be funding to install the instrumentation developed in a prior contract, install a new design for the connector (joint) between coils, and operate the WB-7 with the modifications. The modified unit is now called WB-7.1. This pre-solicitation started as a $200k contract but the final award was for $300k, which suggests that the earlier pre-solicitations were included in this one.

In April 2009, the DoD published a plan to provide Polywell a further $2&nbsp;million in funding as part of the American Recovery and Reinvestment Act 2009. The citation in the legislation was labelled as ''Plasma Fusion (Polywell) - Demonstrate fusion plasma confinement system for shore and shipboard applications; Joint OSD/USN project.''<ref>{{cite web
| url = http://www.defenselink.mil/recovery/plans_reports/2009/march/Final_ARRA_Report_to_Congress-24_Mar_09ver2.pdf
| title = American Recovery and Reinvestment Act of 2009 - Department of Defense Expenditure Plans
| accessdate = 2009-05-05
| year = 2009
| month = May
| format = PDF Report to US Congress
| publisher = Defencelink.mil
}}</ref> The citation occurs 166 pages into the document, and suggests development of the device for 'Domestic Energy Supply / Distribution'.

In May 2009, Richard Nebel was interviewed in a popular science/futurism blog. He stated: "We are hoping to have a net energy production product within six years. It could take longer, but this definitely won't be a 50 year development project. [...] So if the concept works we could have a commercial plant operating as early as 2020."<ref>{{cite web
| url = http://nextbigfuture.com/2009/05/interview-dr-richard-nebel-of.html
| title = Interview Dr. Richard Nebel of IEC/Bussard Fusion Project
| accessdate = 2009-05-05
| year = 2009
| month = May
| format = [[HTML]] document
| publisher = Next Big Future
}}</ref>

In September 2009, the FBO (Federal Business Opportunities web site) confirmed the award of Recovery Act funding under Navy contract in the amount of $7.86M for the construction and testing of WB-8, the next Polywell prototype. This device will have an eightfold increase in magnetic field strength compared to previous WB series devices, with the expectation of higher performance. Of particular importance within the Navy contract is the option for an additional $4.46M for ''...based on the results of WB8 testing, and the availability of government funds the contractor shall develop a WB machine (WB8.1) which incorporates the knowledge and improvements gained in WB8. It is expected that higher ion drive capabilities will be added, and that a “PB11” reaction will be demonstrated''.<ref name="SOA-WB8">{{cite web
| url = https://www.neco.navy.mil/upload/N68936/N6893609R0044RFP_09-R-0044.pdf
| title = Statement of work for advanced gaseous electrostatic energy (AGEE) concept exploration
| accessdate = 2009-06-18
| year = 2009
| month = June
| format = [[PDF]] document
| publisher = United States Navy
}}</ref>

In September 2009, the US Department of Defense announced this award as required by law. The announcement stated that the funding was provided for ''research, analysis, development, and testing in support of the Plan Plasma Fusion (Polywell) Project. Efforts under this Recovery Act award will validate the basic physics of the Plasma Fusion (Polywell) concept, as well as provide the Navy with data for potential applications of polywell fusion.'' <ref>{{cite web
| url = http://www.globalsecurity.org/military/library/news/2009/09/dod-contracts_4116.htm
| title = U.S. Department of Defense - Office of the Assistant Secretary of Defense (Public Affairs) - Contracts
| accessdate = 2009-09-13
| year = 2009
| month = September
| format = [[HTML]] document
| publisher = United States Department of Defence
}}</ref> The basic contract for WB-8 is expected to be completed by April 2011. The optional contract for WB-8.1 has a completion date of 31-Oct-2012.

=== FY 2010 and out year work ===

Other than the Recovery Act Tracking site,<ref>[http://www.recovery.gov/Transparency/RecipientReportedData/pages/RecipientProjectSummary508.aspx?AwardIdSur=46419&AwardType=Contracts U.S. Recovery.gov Track The Money website]</ref> there has been no indication to date of the progress being made on this contract.

The contract<ref name="SOA-WB8"/> has these delivery dates for the Contract Line Item Numbers (CLINs).
* CLIN 0001 - 30 Apr 2010 (= plasma wiffleball 8 ) - Completion of device build.
* CLIN 0002 - 30 Apr 2011 (= Data) - Completion of WB8 testing
* CLIN 0003 - 31 Oct 2011 (= Optional WB 8.1) - Completion of optional device build
* CLIN 0004 - 31 Oct 2012 (= Optional Data) - Completion of optional device testing

The first quarterly report on the Recovery Act site stated:
The main focus of this quarter was the design, procurement and construction of equipment for the new WB-8 Polywell device. Theoretical work was also intiated to build the computational tools required to analyze and understand the data from WB-8.

The second quarterly report on the Recovery Act site stated:
on budget, on schedule for new lab test facility. Primary focus has been construction, procurement and relocation of personnel and chamber. 

As of 31 Aug 2010 a third quarterly report on the Recovery Act site has not been published.

<gallery></gallery>

== See also ==

* [[Aneutronic fusion]] including the pB11 (proton and Boron-11) fusion reaction.
* [[Tokamak]]

== References ==

{{Reflist|2}}

== External links ==
* [http://video.google.com/videoplay?docid=1996321846673788606 Should Google Go Nuclear?] Video of Dr. Bussard's presentation to Google.
* [http://askmar.com/ConferenceNotes/Should%20Google%20Go%20Nuclear.pdf Should Google Go Nuclear?(transcript)] Illustrated transcript of Bussard's Google presentation.
* [http://video.google.com/videoplay?docid=8301617273665558256 Economic Impact of Cheap Fusion] Three minutes of excerpts from Bussard's Google presentation.
* [http://www.emc2fusion.org/ EMC2 Fusion Development Corporation] Official website of Dr. Bussard's non-profit with links to papers.
* [http://isdc2.xisp.net/~kmiller/isdc_archive/fileDownload.php/?link=fileSelect&file_id=422 Presentation] at International Space Development Conference (ISDC). Dallas, May 2007.
* [http://www.strout.net/info/science/polywell/index.html Links] Compendium of informative links related to polywell fusion.
* [http://www.askmar.com/Fusion.html List] of technical papers and references.
* [http://www.youtube.com/watch?v=jmp1cg3-WDY IEC Fusion for Dummies] Youtube video with a graphical explanation of a polywell.
* [http://www.talk-polywell.org/bb/index.php Talk-Polywell.org] BBS for discussing polywell.
* [http://iec.neep.wisc.edu/overview.php University of Wisconsin–Madison] Introduction to [[inertial electrostatic confinement|IEC]] including the polywell.
* [http://www.santafenewmexican.com/SantaFeNorthernNM/Robert_Bussard__1928_2007_Physicist_known_for_pursuits_into_fus Obituary for Dr. Bussard].
* [http://cosmiclog.msnbc.msn.com/archive/2008/06/12/1136887.aspx Latest Fusion developments (WB-7 - June 2008) based on the work of Dr. Robert Bussard]
* [http://www.youtube.com/watch?v=6MYrVVrKua4&feature=related Film about the Polywell with Thomas Ligon]
* [http://prometheusfusionperfection.com/ Prometheus Fusion] - A blog describing amateur experiments aimed at creating a polywell.


[[Category:Fusion power]]