Editing Inertial electrostatic confinement (section)

==Designs with cage==

===Fusor===

The best known IEC device is the fusor.<ref name="Hirsch"/> This device typically consists of two wire cages inside a vacuum chamber. These cages are referred to as grids. The inner cage is held at a negative voltage against the outer cage. A small amount of [[nuclear fuel#Fusion fuels|fusion fuel]] is introduced ([[deuterium]] gas being the most common). The voltage between the grids causes the fuel to ionize. The positive ions fall down the voltage drop toward the negative inner cage. As they accelerate, the [[electric field]] does [[work (electrical)|work]] on the ions, accelerating them to fusion conditions. If these ions collide, they can fuse. Fusors can also use [[particle accelerator|ion gun]]s rather than electric grids. Fusors are popular with amateurs,<ref>{{cite web |title=The Open Source Fusor Research Consortium |website=fusor.net |url=https://fusor.net/ |access-date=January 7, 2014 |url-status=live |archive-url=https://web.archive.org/web/20200904123324/http://www.fusor.net/ |archive-date=September 4, 2020 |quote=Since its inception in 1998, Fusor.net has provided valuable educational resources for hundreds of amateur scientists around the world. There is absolutely no cost to users for these abundant resources.}}</ref> because they can easily be constructed, can regularly produce fusion and are a practical way to study [[nuclear physics]]. Fusors have also been used as a commercial [[neutron generator]] for industrial applications.<ref>{{cite web |title=- Gradel - Neutron generators of the latest technology with multiple possible applications. |first=awesome Webdesign Bremen |last=Oldenburg |website=nsd-fusion.com |url=http://www.nsd-fusion.com/ |access-date=2014-01-09 |url-status=live |archive-url=https://web.archive.org/web/20201020063106/http://www.nsd-fusion.com/ |archive-date=2020-10-20}}</ref>

No fusor has come close to producing a significant amount of [[fusion power]]. They can be dangerous if proper care is not taken because they require high voltages and can produce harmful radiation ([[neutrons]] and [[X-ray]]s). Often, ions collide with the cages or wall. This [[electrical conductor|conducts]] energy away from the device limiting its performance. In addition, collisions heat the grids, which limits high-power devices. Collisions also spray high-mass ions into the reaction chamber, pollute the plasma, and cool the fuel.

===POPS===

In examining [[nonthermal plasma]], workers at [[Los Alamos National Laboratory|LANL]] realized that scattering was more likely than fusion. This was due to the [[Coulomb collision|coulomb scattering]] cross section being larger than the fusion cross section.<ref>{{cite journal |last1=Evstatiev |first1=E. G. |last2=Nebel |first2=R. A. |last3=Chacón |first3=L. |last4=Park |first4=J. |last5=Lapenta |first5=G. |year=2007 |title=Space charge neutralization in inertial electrostatic con?nement plasmas |journal=Phys. Plasmas |volume=14 |issue=4 |page=042701 |bibcode=2007PhPl...14d2701E |doi=10.1063/1.2711173 |url=https://zenodo.org/record/1232027 |access-date=2019-12-11 |url-status=live |archive-url=https://web.archive.org/web/20220712185644/https://zenodo.org/record/1232027 |archive-date=2022-07-12}}</ref> In response they built POPS,<ref>{{cite journal |last1=Park |first1=J. |last2=Nebel |first2=R. A. |last3=Stange |first3=S. |last4=Murali |first4=S. Krupakar |title=Periodically oscillating plasma sphere |journal=Physics of Plasmas |volume=12 |issue=5 |pages=056315 |issn=1070-664X |doi=10.1063/1.1888822 |date=2005 |bibcode=2005PhPl...12e6315P |url=https://zenodo.org/records/1231941/files/article.pdf |archive-url= |archive-date=}}</ref><ref name="park">{{cite journal |last1=Park |first1=J. |display-authors=etal |year=2005 |title=Experimental Observation of a Periodically Oscillating Plasma Sphere in a Gridded Inertial Electrostatic Confinement Device |journal=Phys. Rev. Lett. |volume=95 |issue=1 |page=015003 |bibcode=2005PhRvL..95a5003P |pmid=16090625 |doi=10.1103/PhysRevLett.95.015003 |url=https://zenodo.org/record/1233951 |access-date=2020-09-09 |url-status=live |archive-url=https://web.archive.org/web/20201023003428/https://zenodo.org/record/1233951 |archive-date=2020-10-23}}</ref> a machine with a wire cage, where ions are moving at steady-state, or oscillating around. Such plasma can be at local thermodynamic equilibrium.<ref name=Barnes1998}<ref>R. A. Nebel and D. C. Barnes, ''Fusion Technol.'' 38, 28, 1998.</ref> The ion oscillation is predicted to maintain the equilibrium distribution of the ions at all times, which would eliminate any power loss due to Coulomb scattering, resulting in a [[net energy gain]]. Working off this design, researchers in Russia simulated the POPS design using [[particle-in-cell]] code in 2009.<ref>{{cite journal |last1=Kurilenkov |first1=Yu. K. |last2=Tarakanov |first2=V. P. |last3=Gus'kov |first3=S. Yu. |title=Inertial electrostatic confinement and nuclear fusion in the interelectrode plasma of a nanosecond vacuum discharge. II: Particle-in-cell simulations |journal=Plasma Physics Reports |publisher=Pleiades Publishing Ltd |volume=36 |issue=13 |year=2010 |issn=1063-780X |pages=1227–1234 |bibcode=2010PlPhR..36.1227K |s2cid=123118883 |doi=10.1134/s1063780x10130234}}</ref> This reactor concept becomes increasingly efficient as the size of the device shrinks. However, very high transparencies (>99.999%) are required for successful operation of the POPS concept. To this end S. Krupakar Murali et al., suggested that [[carbon nanotube]]s can be used to construct the cathode grids.<ref name="S. Krupakar Murali">S. Krupakar Murali et al.,"Carbon Nanotubes in IEC Fusion Reactors", ANS 2006 Annual Meeting, June 4–8, Reno, Nevada.</ref> This is also the first (suggested) application of carbon nanotubes directly in any fusion reactor.