Editing Nuclear fusion (section)

===Beam–beam or beam–target fusion===
{{main|Colliding beam fusion}}

Accelerator-based light-ion fusion is a technique using [[particle accelerator]]s to achieve particle kinetic energies sufficient to induce light-ion fusion reactions.<ref>{{Cite book |url=https://link.springer.com/book/10.1007/978-3-030-62308-1 |title=Accelerator Technology |series=Particle Acceleration and Detection |year=2020 |language=en |doi=10.1007/978-3-030-62308-1 |isbn=978-3-030-62307-4 |s2cid=229610872 |last1=Möller |first1=Sören |access-date=20 September 2022 |archive-date=23 September 2022 |archive-url=https://web.archive.org/web/20220923225830/https://link.springer.com/book/10.1007/978-3-030-62308-1 |url-status=live }}</ref>

Accelerating light ions is relatively easy, and can be done in an efficient manner—requiring only a vacuum tube, a pair of electrodes, and a high-voltage transformer; fusion can be observed with as little as 10 kV between the electrodes.{{citation needed|date=August 2023}} The system can be arranged to accelerate ions into a static fuel-infused target, known as ''beam–target'' fusion, or by accelerating two streams of ions towards each other, ''beam–beam'' fusion.{{citation needed|date=August 2023}} The key problem with accelerator-based fusion (and with cold targets in general) is that fusion cross sections are many orders of magnitude lower than Coulomb interaction cross-sections. Therefore, the vast majority of ions expend their energy emitting [[bremsstrahlung]] radiation and the ionization of atoms of the target. Devices referred to as sealed-tube [[neutron generator]]s are particularly relevant to this discussion. These small devices are miniature particle accelerators filled with deuterium and tritium gas in an arrangement that allows ions of those nuclei to be accelerated against hydride targets, also containing deuterium and tritium, where fusion takes place, releasing a flux of neutrons. Hundreds of neutron generators are produced annually for use in the petroleum industry where they are used in measurement equipment for locating and mapping oil reserves.{{citation needed|date=August 2023}}

A number of attempts to recirculate the ions that "miss" collisions have been made over the years. One of the better-known attempts in the 1970s was [[Migma]], which used a unique particle [[storage ring]] to capture ions into circular orbits and return them to the reaction area. Theoretical calculations made during funding reviews pointed out that the system would have significant difficulty scaling up to contain enough fusion fuel to be relevant as a power source. In the 1990s, a new arrangement using a [[field-reversed configuration]] (FRC) as the storage system was proposed by [[Norman Rostoker]] and continues to be studied by [[TAE Technologies]] {{as of|2021|lc=yes}}. A closely related approach is to merge two FRC's rotating in opposite directions,<ref>J. Slough, G. Votroubek, and C. Pihl, "Creation of a high-temperature plasma through merging and compression of supersonic field reversed configuration plasmoids" Nucl. Fusion 51,053008 (2011).</ref> which is being actively studied by [[Helion Energy]]. Because these approaches all have ion energies well beyond the [[Coulomb barrier]], they often suggest the use of alternative fuel cycles like p-[[Boron#Depleted boron (boron-11)|<sup>11</sup>B]] that are too difficult to attempt using conventional approaches.<ref>A. Asle Zaeem et al "Aneutronic Fusion in Collision of Oppositely Directed Plasmoids" Plasma Physics Reports, Vol. 44, No. 3, pp. 378–386 (2018).</ref>

==== Element synthesis ====
{{See also|Superheavy element}}
Fusion of very heavy target nuclei with accelerated ion beams is the primary method of element synthesis. In early 1930s nuclear experiments, deuteron beams were used, to discover the first synthetic elements, such as [[technetium]], [[neptunium]], and [[plutonium]]:

<math chem="">\begin{align}
\ce{ {^{238}_{92}U} + {^{2}_{1}H} ->} &\ce{ {^{238}_{93}Np} + 2^{1}_{0}n}
\end{align}</math>

Fusion of very heavy target nuclei with heavy ion beams has been used to discover [[Superheavy element|superheavy elements]]:

<math chem="">\begin{align}
\ce{ {^{208}_{82}Pb} + {^{62}_{28}Ni} ->} &\ce{ {^{269}_{110}Ds} + ^{1}_{0}n}
\end{align}</math>

<math chem="">\begin{align}
\ce{ {^{249}_{98}Cf} + {^{48}_{20}Ca} ->} &\ce{ {^{294}_{118}Og} + 3^{1}_{0}n}
\end{align}</math>