Editing Fermilab (section)

===Fermilab Accelerator Complex===
Since 2013, the first stage in the acceleration process (pre-accelerator injector) in the Fermilab chain of accelerators<ref>{{cite web |title=Animation of Fermilab's Accelerator Complex |url=https://www.youtube.com/watch?v=vElqxVUoKSE&feature=youtu.be | archive-url=https://ghostarchive.org/varchive/youtube/20211211/vElqxVUoKSE| archive-date=December 11, 2021 | url-status=live|website=YouTube | date=March 21, 2018 |publisher=Fermilab |access-date=February 25, 2021}}{{cbignore}}</ref> takes place in two [[ion source]]s which ionize [[hydrogen]] gas. The gas is introduced into a container lined with molybdenum electrodes, each a matchbox-sized, oval-shaped cathode and a surrounding anode, separated by 1&nbsp;mm and held in place by glass ceramic insulators. A [[magnetron|cavity magnetron]] generates a plasma to form the ions near the metal surface. The ions are accelerated by the source to 35&nbsp;[[keV]] and matched by low energy beam transport (LEBT) into the [[radio-frequency quadrupole]] (RFQ) which applies a 750&nbsp;[[keV]] electrostatic field giving the ions their second acceleration. At the exit of RFQ, the beam is matched by medium energy beam transport (MEBT) into the entrance of the [[linear accelerator]] (linac).<ref>{{cite conference |first1=J.P. |last1=Carneiro |first2=F.G. |last2=Garcia |first3=J.-F. |last3=Ostiguy |first4=A. |last4=Saini |first5=R. |last5=Zwaska |title=Transmission efficiency measurement at the FNAL 4-rod RFQ (FERMILAB-CONF-14-452-APC) |journal=27th International Linear Accelerator Conference (LINAC14) |date=November 13, 2014 |url=https://www-ad.fnal.gov/proton/PIP/Communicate/Calendar/Repository/2014/MOPP050_Linac2014_Carneiro.pdf |access-date=August 12, 2015 |arxiv=1411.3614 |isbn=978-3-95450-142-7 |pages=168–170 |bibcode=2014arXiv1411.3614C |url-status=live |archive-url=https://web.archive.org/web/20160423174912/https://www-ad.fnal.gov/proton/PIP/Communicate/Calendar/Repository/2014/MOPP050_Linac2014_Carneiro.pdf |archive-date=April 23, 2016 }}</ref>

The next stage of acceleration is a linear particle accelerator (linac). This stage consists of two segments. The first segment has five drift tube cavities, operating at 201&nbsp;MHz. The second stage has seven&nbsp;side-coupled cavities, operating at 805&nbsp;MHz. At the end of linac, the particles are accelerated to 400&nbsp;[[MeV]], or about 70% of the [[speed of light]].<ref name=slideshow>{{cite web |title=Fermilab Linac Slide Show Description |url=http://www-ad.fnal.gov/proton/NewProtonWWW/NewLinacWWW/images/stamps/slideShow.html |website=Fermilab |access-date=August 12, 2015 |url-status=live |archive-url=https://web.archive.org/web/20160418203333/http://www-ad.fnal.gov/proton/NewProtonWWW/NewLinacWWW/images/stamps/slideShow.html |archive-date=April 18, 2016}}</ref><ref>{{cite book |last1=Kubik |first1=Donna |title=Fermilab |date=2005 |url=http://home.fnal.gov/~kubik/Accelerators/Fermilab.pdf |access-date=August 12, 2015 |url-status=live |archive-url=https://web.archive.org/web/20160422151506/http://home.fnal.gov/~kubik/Accelerators/Fermilab.pdf |archive-date=April 22, 2016}}</ref> Immediately before entering the next accelerator, the H<sup>−</sup> ions pass through a carbon foil, becoming H<sup>+</sup> ions ([[proton]]s).<ref name=accelerator>{{cite web |title=Accelerator |url=http://www.fnal.gov/pub/tevatron/tevatron-accelerator.html |website=Fermilab |access-date=August 12, 2015 |url-status=live |archive-url=https://web.archive.org/web/20150804144005/http://www.fnal.gov/pub/tevatron/tevatron-accelerator.html |archive-date=August 4, 2015}}</ref>

The resulting protons then enter the booster ring, a {{cvt|468|m|ft}} circumference circular accelerator whose magnets bend beams of protons around a circular path. The protons travel around the Booster about 20,000&nbsp;times in 33&nbsp;milliseconds, adding energy with each revolution until they leave the Booster accelerated to 8&nbsp;[[GeV]].<ref name=accelerator/> In 2021, the lab announced that its latest superconducting [[Yttrium barium copper oxide|YBCO]] magnet could increase field strength at a rate of 290 [[Tesla (unit)|tesla]] per second, reaching a peak magnetic field strength of around 0.5 tesla.<ref>{{Cite web|last=Lavars|first=Nick|date=December 2, 2021|title=Next-gen particle accelerator magnet ramps up at record speed|url=https://newatlas.com/technology/next-generation-particle-accelerator-magnet-record-speed/|access-date=December 2, 2021|website=New Atlas|language=en-US}}</ref>

The final acceleration is applied by the Main Injector [circumference {{cvt|3319.4|m|ft}}], which is the smaller of the two rings in the last picture below (foreground). Completed in 1999, it has become Fermilab's "particle switchyard"<ref>{{cite web |title=Switchyard |url=https://www.fnal.gov/pub/news03/definitions/switchyard.html |website=Operation Terminology |publisher=Fermilab |access-date=1 October 2024}}</ref> in that it can route protons to any of the experiments installed along the beam lines after accelerating them to 120&nbsp;GeV. Until 2011, the Main Injector provided protons to the [[antiproton]] ring [circumference {{cvt|6283.2|m|ft}}] and the [[Tevatron]] for further acceleration but now provides the last push before the particles reach the beam line experiments.

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Two ion sources at Fermilab.jpg|Two ion sources at the center with two high-voltage electronics cabinets next to them<ref name=35years>{{cite web |title=35&nbsp;years of H<sup>−</sup> ions at Fermilab |url=http://www-ad.fnal.gov/proton/PIP/Communicate/Calendar/Repository/2014/35%20years%20of%20H-%20ions%20at%20Fermilab.pdf |website=Fermilab |access-date=12 August 2015 |url-status=live |archive-url=https://web.archive.org/web/20151018080322/http://www-ad.fnal.gov/proton/PIP/Communicate/Calendar/Repository/2014/35%20years%20of%20H-%20ions%20at%20Fermilab.pdf |archive-date=18 October 2015}}</ref>
RFQ MEBT and linac at Fermilab.jpg|Beam direction right to left: RFQ (silver), MEBT (green), first drift tube linac (blue)<ref name=35years/>
The 7835 power amplifiers at Fermilab.JPG|A 7835 power amplifier that is used at the first stage of linac<ref name=slideshow/>
A 12 MW klystron at Fermilab.jpg|A 12&nbsp;MW [[klystron]] used at the second stage of linac<ref name=slideshow/>
The 805 MHz side-couple cavities.jpg|A cutaway view of the 805&nbsp;MHz side-couple cavities<ref>{{cite conference |last1=May |first1=Michael P. |last2=Fritz |first2=James R. |last3=Jurgens |first3=Thomas G. |last4=Miller |first4=Harold W. |last5=Olson |first5=James |last6=Snee |first6=Daniel |title=Mechanical construction of the 805&nbsp;MHz side couple cavities for the Fermilab Linac upgrade |conference=Linear Accelerator Conference |date=1990 |journal=Proceedings of the 1990 Linear Accelerator Conference |url=https://accelconf.web.cern.ch/accelconf/l90/papers/mo423.pdf |access-date=13 August 2015 |location=Albuquerque, New Mexico, USA |url-status=live |archive-url=https://web.archive.org/web/20150707145718/http://accelconf.web.cern.ch/AccelConf/l90/papers/mo423.pdf |archive-date=7 July 2015}}</ref>
Booster ring at Fermilab.jpg|Booster ring<ref>{{cite web |title=Wilson Hall & vicinity |url=https://www.fnal.gov/pub/visiting/map/wilson.html |website=Fermilab |access-date=12 August 2015 |url-status=live |archive-url=https://web.archive.org/web/20150917055551/http://www.fnal.gov/pub/visiting/map/wilson.html |archive-date=17 September 2015}}</ref>
Fermilab.jpg|Fermilab's accelerator rings. The main injector is in the foreground, and the [[antiproton]] ring and [[Tevatron]] (inactive since 2011) are in the background.
Fermilab g-2 (E989) ring.jpg| The E989 storage-ring magnet at Fermilab
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