Editing DESY (section)

== Particle accelerators and other facilities ==
[[File:PETRA III Max von Laue Hall inside 2014.png|thumb|View inside the PETRA III "Max von Laue" hall on the DESY campus in Hamburg]]

[[File:FLASH II 2014.jpg|thumb|FLASH2 experimental hall on the DESY campus in Hamburg]]

[[File: 2018-12-16 DESY-Beschleuniger1.jpg|thumb|LINAC II and DESY II are electron pre-accelerators for the storage ring PETRA III, which, together with the free-electron laser FLASH, serves as a light source for photon science. Also shown is the European XFEL X-ray laser, which runs from the DESY campus to the town of Schenefeld in Schleswig-Holstein.]]

DESY's accelerators were not all built at once, but were rather added one by one to meet the growing demand of the scientists for higher and higher energies to gain more insight into particle structures. In the course of the construction of new accelerators, the older ones were converted to pre-accelerators or to sources for [[synchrotron radiation]] for laboratories with new research tasks.

=== DESY ===
{{main|DESY (particle accelerator)}}

The DESY [[synchrotron]] (short for "Deutsches Elektronen-Synchrotron") has been in operation since 1964. Its circumference is 300&nbsp;m. It was used until 1978 for particle physics experiments and first measurements with synchrotron radiation. Since then, rebuilt and upgraded several times, it has served as a pre-accelerator and as a test beam facility delivering high-energy particle beams for testing detector systems.<ref>[https://particle-physics.desy.de/e252106/ Test beams at DESY]. In: www.desy.de. Retrieved 23 December 2022.</ref>

=== DORIS ===
{{main|DORIS (particle accelerator)}}

The DORIS [[storage ring]] (short for Double Ring Storage Facility) operated from 1974 to 2013. It had a circumference of 289&nbsp;m. Until 1992, it collided electrons with positrons for particle physics experiments (including the [[ARGUS (experiment)|ARGUS]] experiment). From 1980 on, the synchrotron radiation generated by DORIS was used for photon science experiments; from 1993 to 2012, the storage ring served exclusively as a [[synchrotron light source|synchrotron radiation source]]. The particle physics experiment OLYMPUS then ran in 2012 before DORIS was shut down at the beginning of 2013.

=== PETRA <span class="anchor" id="Petra III"></span> ===
{{main|PETRA}}

The PETRA storage ring (short for Positron–Electron Tandem Ring Accelerator) has been in operation since 1978. It has a  circumference of 2,304&nbsp;m. Until 1986, electrons and positrons collided in PETRA for research in particle physics (experiments [[JADE (particle detector)|JADE]], MARK-J, [[TASSO]] and [[PLUTO detector|PLUTO]]). From 1990 on, PETRA served as a pre-accelerator for the [[HERA (particle accelerator)|HERA]] storage ring, and from 1995 on also as a synchrotron radiation source with two test experimental stations. Since 2009, the facility has been delivering [[X-ray#energy ranges|hard X-ray]] beams of very high [[brilliance (synchrotron light)|brilliance]] to over 40 experimental stations under the name [[PETRA III]].<ref>{{cite web |title= PETRA III at DESY |url= https://www.wayforlight.eu/facility/20469|publisher= Way for Light |access-date=19 February 2023}}</ref>

=== HERA ===
{{main|HERA (particle accelerator)}}

The HERA storage ring (short for Hadron–Electron Ring Accelerator) operated from 1992 to 2007. It has a circumference of 6,336&nbsp;m. It was DESY's largest ring accelerator and Germany's largest research instrument to date. Until 2007, HERA was the only storage ring facility in the world to enable collisions of electrons or positrons with protons for particle physics (experiments [[H1 (particle detector)|H1]], [[ZEUS (particle detector)|ZEUS]], [[HERMES experiment|HERMES]] and [[HERA-B]]) for studies of the inner structure of the proton.

=== FLASH ===
{{main|FLASH}}

The [[free-electron laser]] (FEL) FLASH (short for Free-Electron Laser in Hamburg) has been in operation since 2000. It has a length of 315&nbsp;m. It is based on a test facility for superconducting accelerator technology built in 1997 for the [[Teraelectronvolt Energy Superconducting Linear Accelerator|TESLA]] project and has served as a user facility for experiments with the generated FEL radiation since 2005. FLASH provides ultrashort light pulses in the [[extreme ultraviolet]] and [[X-ray#energy ranges|soft X-ray]] range for seven experimental stations and is also used as a test facility for the development of accelerator and FEL technologies.<ref>{{cite web |title= FLASH at DESY |url= https://www.wayforlight.eu/facility/23603|publisher= Way for Light |access-date=19 February 2023}}</ref>

=== European XFEL accelerator ===
{{main|European XFEL}}

DESY operates the 1.7&nbsp;km superconducting [[linear accelerator]] of the European XFEL X-ray free-electron laser, an international research facility that delivers ultrashort light pulses in the high-energy X-ray range.<ref>{{cite web |title= DESY and the European XFEL |url= https://www.xfel.eu/facility/overview/desy/index_eng.html|publisher= European XFEL |access-date=19 February 2023}}</ref>

=== PITZ ===
{{main|PITZ}}

Since 2001, the DESY site in Zeuthen has been home to the photoinjector test facility PITZ, a linear accelerator used to study, optimise and prepare the electron sources for FLASH and (since 2015) for the European XFEL.<ref>{{cite web |title= PITZ homepage |url= https://pitz.desy.de |publisher= DESY |access-date=19 February 2023}}</ref>

=== Other facilities ===
The building of the former DORIS storage ring now houses the SINBAD ("Short Innovative Bunches and Accelerators at DESY")<ref>{{cite web |title= SINBAD |url= https://aries.web.cern.ch/sinbad |publisher= Accelerator Research and Innovation for European Science and Society |access-date=1 March 2023}}</ref> accelerator complex with various infrastructures for accelerator R&D: the linear accelerator ARES for accelerator research with ultrashort electron pulses for medical purposes, the AXSIS facility for [[terahertz radiation|terahertz]]-driven acceleration to generate ultrashort X-ray pulses for materials science or medical imaging, and the high-power laser KALDERA for research into laser-driven [[plasma acceleration]].

The LUX facility is also used for research into laser-driven plasma acceleration, the FLASHForward experiment at FLASH for electron-beam-driven plasma acceleration. The relativistic electron beam source REGAE generates ultrashort electron pulses for time-resolved [[diffraction]] experiments.

The tunnel of the former HERA storage ring now houses the ALPS&nbsp;II experiment, which uses converted superconducting [[dipole magnet]]s of the HERA proton ring to study extremely light particles.<ref>{{cite web |title= ALPS II at MPG |url= https://www.aei.mpg.de/636595/alps-ii |publisher= Max Planck Institute for Gravitational Physics |access-date=1 March 2023}}</ref>

=== Computing ===
DESY provides extensive storage and computing capacity for research in all its divisions. As part of the [[Worldwide LHC Computing Grid]] (WLCG), DESY also operates a Tier-2 computer centre that offers computing and storage systems for the [[ATLAS experiment|ATLAS]], [[Compact Muon Solenoid|CMS]] and [[LHCb]] experiments at the [[Large Hadron Collider]] (LHC). In addition, the DESY grid infrastructure is used by other experiments such as [[Belle II]] or [[IceCube Neutrino Observatory|IceCube]].<ref>[https://it.desy.de/services/computing_infrastructure/index_eng.html Computing infrastructure]. In: www.desy.de. Retrieved 23 December 2022.</ref> DESY (Hamburg) also provides the Maxwell Cluster, a [[high-performance computing]] platform.
<ref>[https://maxwell.desy.de/ DESY Maxwell HPC]. In: maxwell.desy.de. Retrieved 16 December 2024.</ref>