Editing Cyclotron (section)

==Usage==
[[File:Cyclotron - University of Washington.jpg|thumb|upright=1.3|A modern cyclotron used for [[radiation therapy]]. The magnet yoke is painted yellow.]]
=== Basic research ===

For several decades, cyclotrons were the best source of high-energy beams for [[nuclear physics]] experiments.  With the advent of strong focusing synchrotrons, cyclotrons were supplanted as the accelerators capable of producing the highest energies.<ref name="wilson" />{{r|Bryant}} However, due to their compactness, and therefore lower expense compared to high energy synchrotrons, cyclotrons are still used to create beams for research where the primary consideration is not achieving the maximum possible energy.{{r|austin}} Cyclotron based nuclear physics experiments are used to measure basic properties of isotopes (particularly short lived radioactive isotopes) including half life, mass, interaction cross sections, and decay schemes.<ref>{{cite web |title=About Rare-Isotope Research {{!}} TRIUMF : Canada's particle accelerator centre |url=https://www.triumf.ca/research-program/research-topics/rare-isotope-beam-science/rare-isotope#nuc |website=www.triumf.ca |access-date=27 January 2022}}</ref>

=== Medical uses ===
==== Radioisotope production ====

Cyclotron beams can be used to bombard other atoms to produce short-lived isotopes with a variety of medical uses, including [[medical imaging]] and [[radiotherapy]].<ref>{{cite web |title=Cyclotrons – What are They and Where Can you Find Them |url=https://www.iaea.org/newscenter/news/cyclotrons-what-are-they-and-where-can-you-find-them |website=www.iaea.org |publisher=International Atomic Energy Agency |access-date=27 January 2022 |language=en |date=27 January 2021}}</ref>  [[Positron]] and [[gamma radiation|gamma]] emitting isotopes, such as [[fluorine-18]], [[isotopes of carbon#carbon-11|carbon-11]], and [[technetium-99m]]<ref>{{cite news | last=Hume |first=M.  |date=21 February 2012 |title=In a breakthrough, Canadian researchers develop a new way to produce medical isotopes | url=https://www.theglobeandmail.com/news/british-columbia/in-a-breakthrough-canadian-researchers-develop-a-new-way-to-produce-medical-isotopes/article4092466/ | newspaper=[[The Globe and Mail]] |location=Vancouver}}</ref> are used for [[PET imaging|PET]] and [[Single-photon emission computed tomography|SPECT]] imaging. While cyclotron produced radioisotopes are widely used for diagnostic purposes, therapeutic uses are still largely in development.  Proposed isotopes include [[astatine]]-211, [[palladium]]-103, [[rhenium]]-186, and [[bromine]]-77, among others.<ref>{{cite book |title=Cyclotron produced radionuclides : principles and practice. |date=2008 |publisher=International Atomic Energy Agency |location=Vienna |isbn=978-92-0-100208-2}}</ref>

==== Beam therapy ====

The first suggestion that energetic protons could be an effective treatment method was made by [[Robert R. Wilson]] in a paper published in 1946<ref>{{Cite journal |last=Wilson |first=Robert R. |date=1946 |title=Radiological Use of Fast Protons |url=http://dx.doi.org/10.1148/47.5.487 |journal=Radiology |volume=47 |issue=5 |pages=487–491 |doi=10.1148/47.5.487 |pmid=20274616 |issn=0033-8419|url-access=subscription }}</ref> while he was involved in the design of the [[Harvard Cyclotron Laboratory]].<ref>{{Cite book |last=Wilson |first=Richard |url=https://books.google.com/books?id=4cnvAAAAMAAJ&q=A+Brief+History+of+the+Harvard+University+Cyclotrons |title=A Brief History of the Harvard University Cyclotrons |date=2004 |publisher=Harvard University Press |isbn=978-0-674-01460-2 |pages=9 |language=en}}</ref>

Beams from cyclotrons can be used in [[particle therapy]] to treat [[cancer]]. Ion beams from cyclotrons can be used, as in [[proton therapy]], to penetrate the body and kill tumors by [[radiation poisoning|radiation damage]], while minimizing damage to healthy tissue along their path. 

As of 2020, there were approximately 80 facilities worldwide for radiotherapy using beams of protons and heavy ions, consisting of a mixture of cyclotrons and synchrotrons. Cyclotrons are primarily used for proton beams, while synchrotrons are used to produce heavier ions.<ref>{{cite book |title=Regulatory control of the safety of ion radiotherapy facilities : a guide for best practice. |date=2020 |publisher=International Atomic Energy Agency |location=Vienna |isbn=9789201631190 |url=https://www-pub.iaea.org/MTCD/Publications/PDF/TE-1891web.pdf |access-date=27 January 2022}}</ref>