Editing Canadian Light Source (section)

===Accelerators===
[[Image:CLS synchrotron.jpg|thumb|right|250px|The booster and storage rings inside the experimental hall]]
[[File:SGM - PGM EPUs in straight 11 at the Canadian Light Source.jpg|thumb|250x250px|Chicaned undulators inside the storage ring]]

====Injection system====

The injection system consists of a 250 MeV LINAC, a low energy transfer line, a 2.9 GeV booster synchrotron and a high energy transfer line.<ref name="Injection">{{cite web | url=http://accelconf.web.cern.ch/accelconf/e04/papers/thpkf008.pdf| title=Injection system for the Canadian Light Source | year=2004 | accessdate=7 July 2012}}</ref> The LINAC was operated for over 30 years as part of the Saskatchewan Accelerator Lab<ref name="update 2001">{{cite journal | url=http://accelconf.web.cern.ch/accelconf/e04/papers/thpkf008.pdf|title=The Canadian Light Source: an update |journal=19th Particle Accelerator Conference (Pac 2001) |pages=2680 | year=2001 | accessdate=7 July 2012|bibcode=2001pac..conf.2680B |last1=Blomqvist |first1=I. |last2=Dallin |first2=L. |last3=Hallin |first3=E. |last4=Lowe |first4=D. |last5=Silzer |first5=R. |last6=De Jong |first6=M. }}</ref> and operates at 2856&nbsp;MHz. The 78m low energy transfer line takes the electrons from the below-ground LINAC to the ground level booster in the newer CLS building, via two vertical chicanes. The full energy 2.9 GeV booster, chosen to give high orbit stability in the storage ring, operates at 1&nbsp;Hz, with an RF frequency of 500&nbsp;MHz, unsynchronised with the LINAC. This results in significant beam loss at the extraction energy.<ref name="Injection"/>

====Storage ring====

The storage ring cell structure has a fairly compact lattice with twelve straight sections available for injection, [[microwave cavity|RF cavities]] and 9 sections available for insertion devices. Each cell has two bending magnets detuned to allow some dispersion in the straights – the so-called double-bend achromat structure – and thus reduce the overall beam size. As well as the two bend magnets each cell has three families of quadrupole magnets and two families of [[sextupole magnet]]s. The ring circumference is 171m, with a straight section length of 5.2m.<ref name="PAC2001">{{cite journal | url=http://lss.fnal.gov/archive/proceedings/PAPERS/WPPH093.PDF | title=The Canadian Light Source: an update | journal=19th Particle Accelerator Conference (Pac 2001) | pages=2680 | year=2001 | accessdate=28 July 2012 | archive-url=https://web.archive.org/web/20140502032624/http://lss.fnal.gov/archive/proceedings/PAPERS/WPPH093.PDF | archive-date=2 May 2014 | url-status=dead | df=dmy-all | bibcode=2001pac..conf.2680B | last1=Blomqvist | first1=I. | last2=Dallin | first2=L. | last3=Hallin | first3=E. | last4=Lowe | first4=D. | last5=Silzer | first5=R. | last6=De Jong | first6=M. }}</ref> The CLS is the smallest of the newer synchrotron facilities, which results in a relatively high horizontal [[beam emittance]] of 18.2&nbsp;nm-rad.<ref name="Newest" />  The CLS was also one of the first facilities to [[chicane]] two [[undulator]]s in one straight section, to maximize the number of insertion device beamlines.<ref name="SRNupdate"/>

All five of the phase I X-ray beamlines use insertion devices. Four use permanent magnet undulators designed and assembled at the CLS, including one in-vacuum undulator and one elliptically polarized undulator (EPU). The HXMA beamline uses a superconducting [[wiggler (synchrotron)|wiggler]] built by the [[Budker Institute of Nuclear Physics]] in [[Novosibirsk]].<ref name="SRNupdate"/> Phase II added two further devices including another Budker superconducting wiggler, for the BMIT beamline.<ref name="ID">{{cite web| url=http://www.lightsource.ca/operations/insertion_devices.php| title=Insertion devices| accessdate=28 July 2012| archive-date=28 July 2012| archive-url=https://web.archive.org/web/20120728075202/http://www.lightsource.ca/operations/insertion_devices.php| url-status=dead}}</ref> Phase III will add four more devices, filling 8 of the 9 available straight sections. Longer term development includes the replacement of two of the phase I undulators with elliptically polarizing devices.<ref name="IDdev">{{cite web|url=http://accelconf.web.cern.ch/accelconf/IPAC10/papers/wepd005.pdf|title=Insertion Device Development at the Canadian Light Source| year=2010 | accessdate=28 July 2012}}</ref>

Since 2021, the ring operates in a top-up mode during normal user operations,<ref>{{Cite journal |last1=Wurtz |first1=W.A. |last2=Baribeau |first2=C.K. |last3=Sigrist |first3=M.J. |date=2023 |title=Rectifying unexpected injection issues due to an elliptically polarizing undulator |url=http://dx.doi.org/10.1016/j.nima.2022.168001 |journal=Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |volume=1048 |pages=168001 |doi=10.1016/j.nima.2022.168001 |bibcode=2023NIMPA104868001W |s2cid=255182262 |issn=0168-9002|url-access=subscription }}</ref> injecting every few minutes to maintain a stable ring current just below 220 mA. Prior to this change, the ring operated with a fill current of 250mA in decay mode, with two injections per day.<ref name="EllisPiC"/> Facility status is shown on a "machine status" [http://mstatus.lightsource.ca/ webpage], and using the [https://twitter.com/clsfc CLSFC] account on Twitter.<ref name="Gems">{{cite web|url=http://socialmediatoday.com/dezguy/267745/three-useful-twitter-case-studies |title=Three useful Twitter case studies |date=5 February 2011 |accessdate=15 July 2012 |url-status=dead |archiveurl=https://web.archive.org/web/20120613182326/http://socialmediatoday.com/dezguy/267745/three-useful-twitter-case-studies |archivedate=13 June 2012 }}</ref>

==== Superconducting RF cavity ====
The CLS was the first light source to use a [[Superconducting radio frequency|superconducting RF (SRF) cavity]] in the storage ring from the beginning of operations.<ref name="SRNupdate" /> The [[niobium]] cavity is based on the 500&nbsp;MHz design used at the [[Cornell Electron Storage Ring]] (CESR) which allows potentially beam-perturbing high order modes to propagate out of the cavity where they can be very effectively damped.<ref name="PAC2001" />  The superconducting nature of the niobium cavity means only 0.02% of the RF power put into the cavity is wasted in heating the cavity as compared to roughly 40% for normal-conducting (copper) cavities.  However, a large portion of this power saving - about 160&nbsp;kW out of the 250&nbsp;kW saved - is needed to power the cryogenic plant required to supply liquid helium to the cavity.  The SRF cavity at CLS is fed with RF from a 310&nbsp;kW Thales klystron.