Editing Inertial electrostatic confinement (section)

==History==

===1930s===

[[Mark Oliphant]] adapts [[John Cockcroft|Cockcroft]] and [[Ernest Walton|Walton]]'s particle accelerator at the [[Cavendish Laboratory]] to create [[tritium]] and [[helium-3]] by nuclear fusion.<ref>{{cite journal |last1=Oliphant |first1=M. L. E. |last2=Harteck |first2=P. |last3=Rutherford |first3=L. |title=Transmutation Effects Observed with Heavy Hydrogen |journal=Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences |publisher=The Royal Society |volume=144 |issue=853 |date=1934-05-01 |issn=1364-5021 |pages=692–703 |bibcode=1934RSPSA.144..692O |doi=10.1098/rspa.1934.0077 |doi-access=free}}</ref>

===1950s===
[[File:Illustrations of various IEC concepts.png|thumbnail|This picture shows the anode/cathode design for different IEC concepts and experiments.]]

Three researchers at [[Los Alamos National Laboratory|LANL]] including [[James L. Tuck|Jim Tuck]] first explored the idea, theoretically, in a 1959 paper.<ref name="Elmore">{{cite journal |last1=Elmore |first1=William C. |last2=Tuck |first2=James L. |last3=Watson |first3=Kenneth M. |title=On the Inertial-Electrostatic Confinement of a Plasma |journal=Physics of Fluids |publisher=AIP Publishing |volume=2 |issue=3 |year=1959 |issn=0031-9171 |page=239 |bibcode=1959PhFl....2..239E |doi=10.1063/1.1705917}}</ref> The idea had been proposed by a colleague.<ref>W. H. Wells, Bendix Aviation Corporation (private communication, 1954)</ref> The concept was to capture electrons inside a positive cage. The electrons would accelerate the ions to fusion conditions.

Other concepts were being developed which would later merge into the IEC field. These include the publication of the [[Lawson criterion]] by [[John D. Lawson (scientist)|John D. Lawson]] in 1957 in England.<ref>"Some Criteria for a Power Producing Thermonuclear Reactor" J D Lawson, Atomic Energy Research Establishment, Harwell, Berks, 2 November 1956</ref> This puts on minimum criteria on power plant designs which do fusion using hot [[Maxwell–Boltzmann distribution|Maxwellian]] plasma clouds. Also, work exploring how electrons behave inside the [[biconic cusp]], done by [[Harold Grad]] group at the [[Courant Institute of Mathematical Sciences|Courant Institute]] in 1957.<ref>Grad, H. Theory of Cusped Geometries, I. General Survey, NYO-7969, Inst. Math. Sci., N.Y.U., December 1, 1957</ref><ref>Berkowitz, J., Theory of Cusped Geometries, II. Particle Losses, NYO-2530, Inst. Math. Sci., N.Y.U., January 6, 1959.</ref> A biconic cusp is a device with two alike magnetic poles facing one another (i.e. north-north). Electrons and ions can be trapped between these.

===1960s===

[[File:US3386883 - fusor.png|thumb|upright=0.8|{{US patent|3,386,883}} - Schematic from Philo Farnsworth 1968 patent. This device has an inner cage to make the field, and four ion guns on the outside.]]

In his work with vacuum tubes, [[Philo Farnsworth]] observed that electric charge would accumulate in regions of the tube. Today, this effect is known as the [[multipactor effect]].<ref>Cartlidge, Edwin. The Secret World of Amateur Fusion. Physics World, March 2007: IOP Publishing Ltd, pp. 10-11. {{ISSN|0953-8585}}.</ref> Farnsworth reasoned that if ions were concentrated high enough they could collide, and fuse. In 1962, he filed a patent on a design using a positive inner cage to concentrate plasma, in order to achieve nuclear fusion.<ref>US Patent 3,258,402 June 28, 1966</ref> During this time, [[Robert L. Hirsch]] joined the [[Philo Farnsworth|Farnsworth Television labs]] and began work on what became the [[fusor]]. Hirsch patented the design in 1966<ref>US Patent 3,386,883 June 4, 1968</ref> and published the design in 1967.<ref name="Hirsch">{{cite journal |last1=Hirsch |first1=Robert L. |title=Inertial-Electrostatic Confinement of Ionized Fusion Gases |journal=Journal of Applied Physics |volume=38 |issue=7 |pages=4522–4534 |year=1967 |bibcode=1967JAP....38.4522H |doi=10.1063/1.1709162}}</ref> The [[Robert L. Hirsch|Hirsch]] machine was a 17.8&nbsp;cm diameter machine with 150 kV voltage drop across it and used ion beams to help inject material.

Simultaneously, a key plasma physics text was published by [[Lyman Spitzer]] at [[Princeton University|Princeton]] in 1963.<ref>Lyman J Spitzer, "The Physics of Fully Ionized Gases" 1963</ref> Spitzer took the ideal gas laws and adapted them to an ionized plasma, developing many of the fundamental equations used to model a plasma. Meanwhile, [[magnetic mirror]] theory and [[direct energy conversion]] were developed by [[Richard F. Post]]'s group at [[LLNL]].<ref>{{cite journal |last=Kelley |first=G G |title=Elimination of ambipolar potential-enhanced loss in a magnetic trap |journal=Plasma Physics |publisher=IOP Publishing |volume=9 |issue=4 |date=1967-01-01 |pages=503–505 |issn=0032-1028 |doi=10.1088/0032-1028/9/4/412}}</ref><ref name="Mirror Systems 1969">"Mirror Systems: Fuel Cycles, loss reduction and energy recovery" by Richard F. Post, BNES Nuclear fusion reactor conferences at Culham laboratory, September 1969.</ref> A magnetic mirror or magnetic bottle is similar to a biconic cusp except that the poles are reversed.

===1980s===

In 1980 [[Robert W. Bussard]] developed a cross between a fusor and [[magnetic mirror]], the [[polywell]]. The idea was to confine a non-neutral plasma using magnetic fields. This would, in turn, attract ions. This idea had been published previously, notably by [[Oleg Lavrentiev]] in Russia.<ref>{{cite journal |last1=Sadowsky |first1=M |year=1969 |title=Spherical Multipole Magnets for Plasma Research |journal=Rev. Sci. Instrum. |volume=40 |issue=12 |page=1545 |bibcode=1969RScI...40.1545S |doi=10.1063/1.1683858}}</ref><ref>"Confinement d'un Plasma par un Systemem Polyedrique a' Courant Alternatif", ''Z. Naturforschung'' Vol. 21 n, pp. 1085–1089 (1966)</ref><ref>{{cite journal |year=1975 |last1=Lavrent'ev |first1=O.A. |title=Electrostatic and Electromagnetic High-Temperature Plasma Traps |journal=Ann. N.Y. Acad. Sci. |volume=251 |pages=152–178 |bibcode=1975NYASA.251..152L |s2cid=117830218 |doi=10.1111/j.1749-6632.1975.tb00089.x}}</ref> Bussard patented<ref name="ReferenceA">R.W.Bussard in U.S.Patent 4,826,646, "Method and apparatus for controlling charged particles", issued May 2, 1989</ref> the design and received funding from [[Defense Threat Reduction Agency]], [[DARPA]] and the US [[United States Navy|Navy]] to develop the idea.<ref>Dr. Robert Bussard (lecturer) (2006-11-09). "Should Google Go Nuclear? Clean, cheap, nuclear power (no, really)" (Flash video). Google Tech Talks. Google. Retrieved 2006-12-03.</ref>

===1990s===

Bussard and [[Nicholas Krall]] published theory and experimental results in the early nineties.<ref>{{cite journal |last1=Krall |first1=N. A. |last2=Coleman |first2=M. |last3=Maffei |first3=K. |last4=Lovberg |first4=J. |last5=Jacobsen |first5=R. |last6=Bussard |first6=R. W. |year=1995 |title=Forming and maintaining a potential well in a quasispherical magnetic trap |journal=Physics of Plasmas |volume=2 |issue=1 |pages=146–158 |bibcode=1995PhPl....2..146K |s2cid=55528467 |doi=10.1063/1.871103 |doi-access=free }}</ref><ref>"Inertial electrostatic fusion (IEF): A clean energy future" (Microsoft Word document). Energy/Matter Conversion Corporation. Retrieved 2006-12-03.</ref> In response, Todd Rider at [[MIT]], under [[Lawrence Lidsky]] developed general models of the device.<ref name="Plasma Physics 1995"/> Rider argued that the device was fundamentally limited. That same year, 1995, William Nevins at [[LLNL]] published a criticism of the polywell.<ref name=Nevins1995>{{cite journal |last=Nevins |first=W. M. |title=Can inertial electrostatic confinement work beyond the ion–ion collisional time scale? |journal=Physics of Plasmas |publisher=AIP Publishing |volume=2 |issue=10 |year=1995 |issn=1070-664X |pages=3804–3819 |bibcode=1995PhPl....2.3804N |doi=10.1063/1.871080 |osti=41400 |url=https://www.osti.gov/biblio/41400 |access-date=2020-09-09 |url-status= |archive-url= |archive-date=}}</ref> Nevins argued that the particles would build up [[angular momentum]], causing the dense core to degrade.

In the mid-nineties, Bussard publications prompted the development of fusors at the [[University of Wisconsin–Madison]] and at the [[University of Illinois at Urbana–Champaign]]. Madison's machine was first built in 1995.<ref>{{cite web |title=Inertial Electrostatic Confinement Project - University of Wisconsin - Madison |website=iec.neep.wisc.edu |url=https://iec.neep.wisc.edu/results.php |access-date=2023-02-09 |archive-url=https://web.archive.org/web/20140202221946/http://iec.neep.wisc.edu/results.php |archive-date=2014-02-02}}</ref> [[George H. Miley]]'s team at Illinois built a 25&nbsp;cm fusor which has produced 10<sup>7</sup> neutrons using deuterium gas<ref name="Physics Research 1999">{{cite journal |last=Miley |first=George H. |title=A portable neutron/tunable X-ray source based on inertial electrostatic confinement |journal=Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |publisher=Elsevier BV |volume=422 |issue=1–3 |year=1999 |issn=0168-9002 |pages=16–20 |bibcode=1999NIMPA.422...16M |doi=10.1016/s0168-9002(98)01108-5|citeseerx=10.1.1.567.7259 }}</ref> and discovered the "star mode" of fusor operation in 1994.<ref>Miley Abstract Accomplishments, www.avrc.com/Miley_abstract_accomplishments.doc</ref> The following year, the first "US-Japan Workshop on IEC Fusion" was conducted. This is now the premier conference for IEC researchers. At this time in Europe, an IEC device was developed as a commercial neutron source by [[DaimlerChrysler Aerospace|Daimler-Chrysler Aerospace]] under the name FusionStar.<ref>{{cite journal |year=2000 |title=The IEC star-mode fusion neutron source for NAA--status and next-step designs |journal=Appl Radiat Isot |volume=53 |issue=4–5 |pages=779–83 |pmid=11003520 |last1=Miley |first1=George H. |last2=Sved |first2=J. |doi=10.1016/s0969-8043(00)00215-3|bibcode=2000AppRI..53..779M }}</ref> In the late nineties, hobbyist Richard Hull began building amateur fusors in his home.<ref name=youtube1>"Living with a nuclear reactor" The Wall Street Journal, interview with Sam Schechner, https://www.youtube.com/watch?v=LJL3RQ4I-iE {{Webarchive|url=https://web.archive.org/web/20160722034843/https://www.youtube.com/watch?v=LJL3RQ4I-iE |date=2016-07-22}}</ref> In March 1999, he achieved a neutron rate of 10<sup>5</sup> neutrons per second.<ref name="prometheusfusionperfection.com">"The Neutron Club", Richard Hull, Accessed 6-9-2011, https://prometheusfusionperfection.com/category/fusor/ {{Webarchive|url=https://web.archive.org/web/20140201210343/http://prometheusfusionperfection.com/category/fusor/ |date=2014-02-01}}</ref> Hull and Paul Schatzkin started fusor.net in 1998.<ref>{{cite web |title=Fusor.net |website=fusor.net |url=https://fusor.net/ |access-date=2014-01-07 |url-status=live |archive-url=https://web.archive.org/web/20200904123324/http://www.fusor.net/ |archive-date=2020-09-04}}</ref> Through this open forum, a community of amateur fusioneers have done nuclear fusion using homemade fusors.

===2000s===

Despite demonstration in 2000 of 7200 hours of operation without degradation at high input power as a sealed reaction chamber with automated control the FusionStar project was canceled and the company NSD Ltd was founded. The spherical FusionStar technology was then further developed as a linear geometry system with improved efficiency and higher neutron output by NSD Ltd. which became [http://www.nsd-fusion.com NSD-Fusion] GmbH in 2005.

In early 2000, Alex Klein developed a cross between a polywell and ion beams.<ref name=mix>"The Multipole Ion-beam eXperiment", Presentation, Alex Klien, 7–8 December 2011, 13th US-Japan IEC workshop, Sydney 2011</ref> Using [[Dennis Gabor|Gabor lensing]], Dr. Klein attempted to focus plasma into non-neutral clouds for fusion. He founded FP generation, which in April 2009 raised $3 million in financing from two venture funds.<ref>{{cite web |title=FP Generation fusion project was funded and built prototypes |website=NextBigFuture.com |date=2011-05-19 |url=https://www.nextbigfuture.com/2011/05/fp-generation-fusion-project-was-funded.html |access-date=2023-02-09 |url-status=live |archive-url=https://web.archive.org/web/20140202171340/http://nextbigfuture.com/2011/05/fp-generation-fusion-project-was-funded.html |archive-date=2014-02-02}}</ref><ref name="AlexPoster"/> The company developed the MIX and Marble machine, but ran into technical challenges and closed.

In response to Riders' criticisms, researchers at [[LANL]] reasoned that a plasma oscillating could be at local thermodynamic equilibrium; this prompted the POPS and Penning trap machines.<ref name=Barnes2002>{{cite journal |last1=Barnes |first1=D. C. |last2=Chacón |first2=L. |last3=Finn |first3=J. M. |title=Equilibrium and low-frequency stability of a uniform density, collisionless, spherical Vlasov system |journal=Physics of Plasmas |publisher=AIP Publishing |volume=9 |issue=11 |year=2002 |issn=1070-664X |pages=4448–4464 |bibcode=2002PhPl....9.4448B |doi=10.1063/1.1510667}}</ref><ref name="ReferenceB">{{cite journal |last1=Mitchell |first1=T. B. |last2=Schauer |first2=M. M. |last3=Barnes |first3=D. C. |title=Observation of Spherical Focus in an Electron Penning Trap |journal=Physical Review Letters |publisher=American Physical Society (APS) |volume=78 |issue=1 |issn=0031-9007 |pages=58–61 |bibcode=1997PhRvL..78...58M |doi=10.1103/physrevlett.78.58 |date=1997-01-06}}</ref> At this time, [[MIT]] researchers became interested in fusors for space propulsion<ref>Ph.D. Thesis "Improving Particle Confinement in Inertial Electrostatic Fusion for Spacecraft Power and Propulsion", Carl Dietrich, Massachusetts Institute of Technology, February 2007</ref> and powering space vehicles.<ref>Ph.D. Thesis "Improved lifetimes and synchronization behavior in Mutlt-grid IEC fusion devices", Tom McGuire, Massachusetts Institute of Technology, February 2007</ref> Specifically, researchers developed [[fusor]]s with multiple inner cages. In 2005, Greg Piefer founded [[Phoenix Nuclear Labs]] to develop the fusor into a neutron source for the mass production of medical isotopes.<ref name=PNL>"Phoenix Nuclear Labs meets neutron production milestone", PNL press release May 1, 2013, Ross Radel, Evan Sengbusch</ref>

[[Robert Bussard]] began speaking openly about the Polywell in 2006.<ref>SirPhilip (posting an e-mail from "RW Bussard") (2006-06-23). "Fusion, eh?". James Randi Educational Foundation forums. Retrieved 2006-12-03.</ref> He attempted to generate interest<ref name="Bussard6">"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> in the research, before passing away from multiple myeloma in 2007.<ref>M. Simon (2007-10-08). "Dr. Robert W. Bussard Has Passed". Classical Values. Retrieved 2007-10-09.</ref> His company was able to raise over ten million in funding from the US Navy in 2008<ref>"A—Polywell Fusion Device Research, Solicitation Number: N6893609T0011". Federal Business Opportunities. October 2008. Retrieved 2008-11-07.</ref><ref>"A—Spatially Resolved Plasma Densities/Particle Energies, Solicitation Number: N6893609T0019". Federal Business Opportunities. October 2008. Retrieved 2008-11-07.</ref> and 2009.<ref>"Statement of work for advanced gaseous electrostatic energy (AGEE) concept exploration" (PDF). United States Navy. June 2009. Retrieved 2009-06-18.</ref>

===2010s===

Bussard's publications prompted the [[University of Sydney]] to start research into electron trapping in polywells in 2010.<ref>{{cite journal |last1=Carr |first1=M. |last2=Khachan |first2=J. |year=2010 |title=The dependence of the virtual cathode in a Polywell™ on the coil current and background gas pressure |journal=Physics of Plasmas |volume=17 |issue=5 |page=052510 |bibcode=2010PhPl...17e2510C |doi=10.1063/1.3428744 |url=https://zenodo.org/record/1244060 |access-date=2019-12-11 |url-status=live |archive-url=https://web.archive.org/web/20200922145423/https://zenodo.org/record/1244060 |archive-date=2020-09-22}}</ref> The group has explored theory,<ref>{{cite journal |last1=Carr |first1=Matthew |year=2011 |title=Low beta confinement in a Polywell modeled with conventional point cusp theories |journal=Physics of Plasmas |volume=18 |issue=11 |page=11 |bibcode=2011PhPl...18k2501C |doi=10.1063/1.3655446 |url=https://zenodo.org/record/1244053 |access-date=2019-12-11 |url-status=live |archive-url=https://web.archive.org/web/20200922144501/https://zenodo.org/record/1244053 |archive-date=2020-09-22}}</ref> modeled devices,<ref name="Oct12013Paper">{{cite journal |last1=Gummershall |first1=Devid |last2=Carr |first2=Matthew |last3=Cornish |first3=Scott |year=2013 |title=Scaling law of electron confinement in a zero beta polywell device |journal=Physics of Plasmas |volume=20 |issue=10 |page=102701 |bibcode=2013PhPl...20j2701G |doi=10.1063/1.4824005}}</ref> built devices, measured trapping<ref name="Carr, M. 2013">{{cite journal |last1=Carr |first1=M. |last2=Khachan |first2=J. |year=2013 |title=A biased probe analysis of potential well formation in an electron only, low beta Polywell magnetic field |journal=Physics of Plasmas |volume=20 |issue=5 |page=052504 |bibcode=2013PhPl...20e2504C |doi=10.1063/1.4804279 |url=https://zenodo.org/record/1244056 |access-date=2019-12-11 |url-status=live |archive-url=https://web.archive.org/web/20200731210347/https://zenodo.org/record/1244056 |archive-date=2020-07-31}}</ref> and simulated trapping. These machines were all low power and cost and all had a small [[plasma beta|beta]] ratio. In 2010, Carl Greninger founded the northwest nuclear consortium, an organization which teaches nuclear engineering principles to high school students, using a 60 kvolt fusor.<ref name="lobby.nwnc.us.com">{{cite web |title=My Account &#124; .xyz &#124; for every website, everywhere® |url=http://lobby.nwnc.us.com/_layouts/15/start.aspx |access-date=2014-01-25 |url-status=usurped |archive-url=https://web.archive.org/web/20131203015356/http://lobby.nwnc.us.com/_layouts/15/start.aspx#/SitePages/Home.aspx |archive-date=2013-12-03}}</ref><ref name="ReferenceC">{{cite web |title=Overview of the North West Nuclear Consortium in 2012 |last=Carl Greninger |via=YouTube |date=16 September 2012 |url=https://www.youtube.com/watch?v=KbeAcFy3ErM |url-status=live |archive-url=https://ghostarchive.org/varchive/youtube/20211221/KbeAcFy3ErM |archive-date=2021-12-21}}{{cbignore}}</ref> In 2012, Mark Suppes received attention,<ref>{{cite web |title=Mark Suppes News, Videos, Reviews and Gossip - Gizmodo |website=Gizmodo |date=23 June 2010 |url=https://gizmodo.com/tag/mark-suppes |access-date=2017-09-09 |url-status=live |archive-url=https://web.archive.org/web/20170427195423/http://gizmodo.com/tag/mark-suppes |archive-date=2017-04-27}}</ref><ref>{{cite web |title=Prometheus Fusion Perfection |website=Prometheus Fusion Perfection |url=https://prometheusfusionperfection.com/ |access-date=2014-01-25 |url-status=live |archive-url=https://web.archive.org/web/20140206174327/http://prometheusfusionperfection.com/ |archive-date=2014-02-06}}</ref> for a fusor. Suppes also measured electron trapping inside a polywell.<ref>{{cite web |title=Man builds web pages by day and nuclear fusion reactors by night |first=Cassie |last=Spodak |publisher=CNN |url=https://www.cnn.com/2010/US/06/24/new.york.nuclear.hobby/ |access-date=2014-01-28 |url-status=live |archive-url=https://web.archive.org/web/20140203125021/http://www.cnn.com/2010/US/06/24/new.york.nuclear.hobby/ |archive-date=2014-02-03}}</ref> In 2013, the first IEC textbook was published by [[George H. Miley]].<ref>Inertial Electrostatic Confinement (IEC) Fusion, fundamentals and applications, {{ISBN|978-1-4614-9337-2}} (Print) 978-1-4614-9338-9, published December 26, 2013</ref>

===2020s===
Avalanche Energy is a start-up with about $51 million in venture/DOD funding that is working on small (tens of centimetres), modular, fusion batteries producing 5kWe. They are targeting 600 kV for their device to achieve certain design goals. Their Orbitron concept electrostatically (magnetron-augmented) confines ions orbiting around a high voltage (100s of kVs) cathode in a high vacuum environment (p< 10 −8 Torr) surrounded by one or two anode shells separated by a dielectric. Concerns include breakdown of the vacuum/dielectric and insulator surface flashover. [[Permanent magnet]]/electromagnet magnetic field generators are arranged coaxially around the anode. The magnetic field strength is targeted to exceed a [[cavity magnetron#Hull or single-anode magnetron|Hull cut-off condition]], ranging from 50-4,000 kV. Candidate ions include protons (m/z=1), deuterium (m/z=2), tritium (m/z=3), lithium-6 (m/z=6), and boron-11 (m/z=11). Recent progress includes successful testing of a 300 kV [[bushing (electrical)|bushing]].<ref>{{cite web |last=Wang |first=Brian |title=Avalanche Energy Making Technical Progress to a Lunchbox Size Nuclear Fusion Device |date=2023-02-08 |website=NextBigFuture.com |url=https://www.nextbigfuture.com/2023/02/avalanche-energy-making-technical-progress-to-a-lunchbox-size-nuclear-fusion-device.html |access-date=2023-02-09}}</ref>