View source for DESY

{{Short description|German national research center}}
{{other uses}}
{{more citations needed|date=December 2012}}
{{Use dmy dates|date=December 2016}}
{{Infobox laboratory
| name             = <big>DESY</big>
| native_name      = Deutsches Elektronen-Synchrotron
| logo             = <br /><small>logo</small>
| image            = [[File:Desy logo 3c web.svg|border|250px]]
| caption          = 
| latin_name       = 
| motto            = "''The Decoding of Matter''"
| established      = {{start date|1959|12|18|df=y}}
| type             = [[Fundamental research]]
| budget           = {{circa}} [[euro|€]] 359 million (2024)
| debt             = 
| research_field   = 
* [[Particle accelerator]]s
* [[Particle physics]]
* [[Photon]] science
* [[Astroparticle physics]]
| president        = 
| vice-president   = 
| dean             = 
| director         = [[Beate Heinemann]]
| faculty          = 
| staff            = 3,000 (plus over 3,000 guest scientists p.a.)
| students         = {{circa}} 500 PhD students and postdocs
| alumni           = 
| address          = Notkestraße 85, <br />{{nowrap|22607 [[Hamburg]], Germany}} <br />Platanenallee 6, <br />{{nowrap|15738 [[Zeuthen]], Germany}}
| coordinates      = {{coord|53|34|33|N|9|52|46|E|region:DE-HH_type:landmark|display=title,inline}}<br />{{coord|52|22|00|N|13|37|00|E|format=dms|display=inline}}
| location_map     = Germany
| campus           = [[Bahrenfeld|Hamburg-Bahrenfeld]], <br />[[Zeuthen]]
| free_label       = 
| free             = 
| affiliations     = [[Helmholtz Association]]
| operating_agency = 
| nobel_laureates  = 
| website          = {{URL|desy.de}}
| footnotes        = 
}}

'''DESY''', short for '''Deutsches Elektronen-Synchrotron''' (English: ''German Electron Synchrotron''), is a national research centre for [[fundamental science]] located in [[Hamburg]] and [[Zeuthen]] near Berlin in [[Germany]]. It operates [[particle accelerator]]s used to investigate the structure, dynamics and function of [[matter]], and conducts a broad spectrum of interdisciplinary scientific research in four main areas: [[particle physics|particle]] and [[high energy physics]]; [[photon]] science; [[astroparticle physics]]; and the development, construction and operation of particle accelerators. Its name refers to its first project, an [[electron]] [[synchrotron]]. DESY is publicly financed by the [[Federal Republic of Germany]] and the Federal States of [[Hamburg]] and [[Brandenburg]] and is a member of the [[Helmholtz Association]].

== Functions and mission ==
DESY's function is to conduct [[fundamental research]] for solely civil and peaceful purposes. It specialises in [[particle accelerator]] development, construction and operation, [[particle physics]], [[astroparticle physics]] and photon science research to explore the fundamental relationships between the structure, dynamics and function of matter. In cooperation with its partner organisations, its photon science research spans surface physics, [[material science]], [[chemistry]], [[molecular biology]], [[geophysics]] and [[medicine]] through the use of [[synchrotron radiation]] and [[free-electron laser]]s.<ref>DESY: Statutes of the Foundation [https://www.desy.de/sites2009/site_www-desy/content/e410/e207099/e207101/211208_DESY-Satzung_ger.pdf Deutsches Elektronen-Synchrotron DESY]. (PDF; 40 KB) In: www.desy.de. 8 December 2021. Retrieved 22 December 2022 (in German).</ref><ref>DESY: [https://www.desy.de/sites2009/site_www-desy/content/e410/e156434/e159719/DESY_Leitbild_englisch_eng.pdf Mission and guiding principles of the research centre DESY]. (PDF; 3 MB) In: www.desy.de. May 2013. Retrieved 22 December 2022.</ref>

In addition to operating its own large accelerator facilities, DESY participates in many major international research projects, for example the [[European X-Ray Free-Electron Laser]] in Germany, the [[Large Hadron Collider]] in Switzerland, the [[Belle II experiment]] in Japan, the [[IceCube Neutrino Observatory]] at the South Pole and the worldwide [[Cherenkov Telescope Array Observatory]].<ref>German Federal Ministry of Education and Research (BMBF): [https://www.bmbf.de/bmbf/de/forschung/naturwissenschaften/grossgeraete/desy-deutsches-elektronen-synchrotron/deutsches-elektronen-synchrotron.html Deutsches Elektronen-Synchrotron – DESY] {{Webarchive|url=https://web.archive.org/web/20230124213549/https://www.bmbf.de/bmbf/de/forschung/naturwissenschaften/grossgeraete/desy-deutsches-elektronen-synchrotron/deutsches-elektronen-synchrotron.html |date=24 January 2023 }}. In: www.bmbf.de. Retrieved 22 December 2022 (in German).</ref>

== Sites ==
[[File:DESY main entrance 2014.jpg|thumb|Main entrance of the DESY campus in Hamburg]]

DESY operates in two locations. The primary location is in the [[Bahrenfeld]] quarter of [[Hamburg]]. In 1992, DESY expanded to a second site in [[Zeuthen]] near [[Berlin]].

=== Hamburg ===
The DESY Hamburg site is located in the quarter [[Bahrenfeld]], in the west of the city in the district of [[Altona, Hamburg|Altona]]. Its main accelerators are located here.

=== Zeuthen ===
Following [[German reunification]], DESY expanded to a second site in [[Zeuthen]] near Berlin. In 1939, the German Postal Ministry founded a nuclear physics laboratory there. After World War II, the laboratory was first named "Institute X", to become the Institute for High Energy Physics ({{langx|de|Institut für Hochenergiephysik IfH}}), the high-energy physics laboratory of the [[German Democratic Republic]] belonging to the [[Academy of Sciences of the GDR]]. The institute was merged with DESY on 1&nbsp;January 1992. It focuses on [[parallel computing]] for theoretical particle physics, the development and construction of electron sources for X-ray lasers as well as [[astroparticle physics]] with a focus on [[gamma-ray]] and [[neutrino]] astronomy.<ref>Matthew Chalmers: [https://cerncourier.com/a/desys-astroparticle-aspirations/]. In: CERN Courier, 8 May 2019. Retrieved 22 December 2022.</ref>

== Employees and training ==
DESY employs about 3,000 staff members from more than 60 nations. Most staff work at the Hamburg site, with about 270 at the Zeuthen site. These numbers include more than 130 trainees in various industrial-technical professions and about 500 PhD students and postdocs supervised by DESY. In addition, there are numerous master students from various universities.<ref>[https://www.desy.de/about_desy/desy/index_eng.html About DESY]. In: www.desy.de. Retrieved 27 March 2024.</ref>

== Budget and financing ==
The research centre is a [[stiftung|foundation under civil law]] financed by public funds. In 2024, DESY had an annual budget of about 359&nbsp;million euros (according to the German federal budget plan as part of institutional funding).<ref>Federal Ministry of Education and Research (BMBF): [https://www.bundeshaushalt.de/static/daten/2024/soll/epl30.pdf Bundeshaushaltsplan 2024 – Einzelplan 30], p. 110. In: www.bundeshaushalt.de. Retrieved 30 October 2025 (in German).</ref> In addition, it had a project funding income of about 32&nbsp;million euros. 90% of the annual budget is provided by the German [[Federal Ministry of Research, Technology and Space]] and 10% respectively by the [[Free and Hanseatic City of Hamburg]]<ref>Free and Hanseatic City of Hamburg: [https://www.hamburg.de/resource/blob/203796/450e85586ee83e6793b0d9990e38676c/gesamthaushalt-2023-2024-data.pdf Gesamthaushalt 2023-2024], p. 76-77. In: www.hamburg.de. Retrieved 30 October 2025 (in German).</ref> and the German federal state of [[Brandenburg]].<ref>Land Brandenburg: [https://mdfe.brandenburg.de/sixcms/media.php/9/06_Ministerium%20für%20Wissenschaft%20Forschung%20und%20Kultur%202023-24.pdf Haushaltsplan 2023/2024 – Band VI, Einzelplan 06], p. 65-66. In: mdfe.brandenburg.de. Retrieved 30 October 2025 (in German).</ref>

== 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 within the Interdisciplinary Data and Analysis Facility (IDAF).<ref>Christoph Beyer et al.: „Beyond HEP: Photon and accelerator science computing infrastructure at DESY“. In: EPJ Web Conf., 245 07036 (2020). Retrieved 22 September 2025. [https://doi.org/10.3204/PUBDB-2020-04519 DOI 10.3204/PUBDB-2020-04519].</ref><ref>[https://idaf.desy.de IDAF: Interdisciplinary Data and Analysis Facility]. In: www.desy.de. Retrieved 22 September 2025.</ref> The Maxwell HPC Cluster, a [[high-performance computing]] platform, serves photon science analysis and accelerator science and operations.<ref>[https://maxwell.desy.de Maxwell HPC Cluster]. In: www.desy.de. Retrieved 22 September 2025.</ref> As part of the [[Worldwide LHC Computing Grid]] (WLCG), DESY 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://grid.desy.de DESY Grid]. In: www.desy.de. Retrieved 22 September 2025.</ref> It is complemented by the National Analysis Facility (NAF) for particle physics data analysis.<ref>[https://naf.desy.de NAF: National Analysis Facility]. In: www.desy.de. Retrieved 22 September 2025.</ref><ref>[https://it.desy.de/services/computing_infrastructure/index_eng.html Computing infrastructure]. In: www.desy.de. Retrieved 23 December 2022.</ref> IDAF storage is provided using [[DCache]] and [[General Parallel File System]] (GPFS).

== Research areas ==
Research at DESY is organised into four divisions: Accelerators, Photon Science, Particle Physics and Astroparticle Physics.

[[File:TTF Cavity-Verbindung im Reinraum 2-a3.jpg|thumb|The superconducting resonators used in the linear accelerators of the free-electron laser FLASH and the European XFEL X-ray laser are processed and assembled in a cleanroom.]]

The Accelerator division develops fundamental technologies for the accelerator facilities that DESY and its partners use in their scientific mission. In addition to the operation and further development of existing facilities (PETRA IV and FLASH2020+ projects, expansion of the European XFEL), essential activities include research into new accelerator concepts, in particular [[plasma wakefield acceleration]], and the improvement of [[superconductivity|superconducting]] [[radio frequency]] accelerator technology.<ref>DESY: [https://www.desy.de/sites2009/site_www-desy/content/e410/e84441/e326618/Accelerators2021_ger.pdf Accelerators 2021. Highlights and Annual Report]. (PDF; 13 MB) In: www.desy.de. Retrieved on 23 December 2022.</ref><ref>Sven Kiele et al: [https://www.helmholtz.de/fileadmin/test/Helmholtz-Photon-Science-Roadmap-2021-Langfassung-210625.pdf National Strategy for the Further Development of Accelerator-Based User Facilities for Research with Photons and with High Electromagnetic Fields ("Helmholtz Photon Science Roadmap")]. (PDF; 6 MB). In: www.helmholtz.de. 15 June 2021. Retrieved 23 December 2022 (in German).</ref>

[[File:2020-04-03_PETRA_III_P11_Coronavirus_CSSB_MM-6489.jpg|thumb|Experiments to investigate the SARS-CoV-2 virus at the PETRA III synchrotron radiation source at DESY]]

In the Photon Science division, [[photon]]s are being used to study the structure, dynamics and function of matter. To this end, the division develops, builds and operates beamlines and experiments at the DESY light sources [[PETRA|PETRA III]] and [[FLASH]]. Every year, more than 3,000 researchers – most of them from universities, but also from non-university research institutions and industry – from over 40 countries conduct experiments at the light sources and in the laboratories at DESY.<ref>[https://www.desy.de/about_desy/desy/index_eng.html About DESY]. In: www.desy.de. Retrieved 23 December 2022.</ref> The research spectrum ranges from [[basic research]] to [[applied science|applied research]] and industrial collaborations in [[physics]], [[chemistry]], [[biology]], [[medicine]], [[life sciences]], [[earth sciences]], [[materials research]] as well as the study of [[cultural property|cultural heritage]].<ref>DESY: [https://www.desy.de/sites2009/site_www-desy/content/e410/e84441/e320963/Photon_Science_Annual_Report_2021_low_res_Feb2022_ger.pdf Photon Science 2021. Highlights and Annual Report]. (PDF; 18 MB) In: www.desy.de. December 2021. Retrieved 23 December 2022.</ref>

[[File:DAF CMS.jpg|thumb|In the Detector Assembly Facility (DAF) at DESY, new, more radiation-resistant and precise silicon tracking detectors are produced for the ATLAS and CMS experiments at the LHC accelerator at CERN (here for CMS).]]

The Particle Physics division is involved in the large-scale experiments at the [[Large Hadron Collider]] (LHC) at [[CERN]] near Geneva. As part of the international collaborations that run the [[ATLAS experiment|ATLAS]] and [[Compact Muon Solenoid|CMS]] experiments, DESY contributes to many developments at the LHC, from hardware design and data analysis to preparations for the planned upgrades. DESY also participates in the [[Belle II experiment]] at the electron–positron collider [[SuperKEKB]] at the research centre [[KEK]] in [[Tsukuba]], Japan, as well as in developments for possible future electron–positron linear colliders. It is also active in theoretical particle physics.<ref>DESY: [https://www.desy.de/sites2009/site_www-desy/content/e410/e84441/e325473/ParticlePhysics2021_ger.pdf Particle Physics 2021. Highlights and Annual Report]. (PDF; 15.4 MB) In: www.desy.de. 2 March 2022. Retrieved 23 December 2022.</ref><ref>Kristiane Novotny: [https://cerncourier.com/a/new-directions-at-desy/ "New directions at DESY"]. In: CERN Courier, 8 March 2022. Retrieved 23 December 2022.</ref>

[[File:IceCube Optisches Modul2 2004.jpg|thumb|DESY produces a large part of the digital optical modules for the neutrino observatory IceCube at the South Pole.]]

The Astroparticle Physics division investigates high-energy processes in the universe. Detectors and telescopes are used to analyse [[neutrino]]s and [[gamma ray]]s from space, which can provide information about cosmic phenomena: [[black hole]]s, [[nova|exploding stars]] and radiation bursts of extreme intensity. To this end, DESY is involved in the gamma telescopes [[MAGIC (telescope)|MAGIC]], [[High Energy Stereoscopic System|H.E.S.S.]] and [[VERITAS]] as well as the [[Fermi Gamma-ray Space Telescope]], and it contributes to the planned [[Cherenkov Telescope Array Observatory]] (CTAO). It is the second largest partner in the [[IceCube Neutrino Observatory]] at the South Pole.<ref>DESY: [https://www.desy.de/sites2009/site_www-desy/content/e410/e84441/e327507/AstroparticlePhysics2021_ger.pdf Astroparticle Physics 2021. Highlights and Annual Report]. (PDF; 10.8 MB) In: www.desy.de. August 2022. Retrieved 23 December 2022.</ref><ref>Matthew Chalmers: [https://cerncourier.com/a/desys-astroparticle-aspirations/ "DESY's astroparticle aspirations"]. In: CERN Courier, 8 May 2019. Retrieved 23 December 2022.</ref>

== History ==
[[Image:Desy.jpg|thumb|German 1984 postal stamp – 25th anniversary of the foundation of DESY]]

DESY was founded on 18&nbsp;December 1959 in Hamburg.<ref name="Lohrmann_Söding_CC">Erich Lohrmann, Paul Söding: [https://cerncourier.com/a/desy-marks-50-years-of-accelerator-research/ "DESY marks 50 years of accelerator research"]. In: CERN Courier, 7 December 2009. Retrieved 23 December 2022.</ref> According to its statutes, DESY's mission is "the promotion of basic scientific research [...] in particular through the development, construction and operation of accelerators and their scientific use, in photon science and in the fields of particle and astroparticle physics, as well as through research and development work related thereto".<ref>DESY: Statutes of the Foundation [https://www.desy.de/sites2009/site_www-desy/content/e410/e207099/e207101/211208_DESY-Satzung_ger.pdf Deutsches Elektronen-Synchrotron DESY]. (PDF; 40 KB) In: www.desy.de. 8 December 2021. Retrieved 23 December 2022 (in German).</ref>

[[Image:DESY2.jpg|thumb|The [[ARGUS (experiment)|ARGUS]] detector at the former electron–positron storage ring DORIS at DESY]]

[[File: 1980-09-22 TASSO-Event Gluon Entdeckung sw.jpg |thumb|In 1979, the particle physics experiments at the electron–positron storage ring PETRA at DESY discovered the gluon, the messenger particle of the strong force.]]

From 1959 to 2007, the DESY accelerators were primarily used for [[particle physics]], initially with the eponymous [[DESY (particle accelerator)|DESY electron synchrotron]] (1964–present), followed by [[DORIS (particle accelerator)|DORIS]] (Double Ring Storage Facility, 1974–1992), [[PETRA]] (Positron–Electron Tandem Ring Facility, 1978–present) and [[HERA (particle accelerator)|HERA]] (Hadron–Electron Ring Accelerator, 1992–2007). In 1987, the [[ARGUS (experiment)|ARGUS]] experiment at DORIS was the first to observe a large mixing of [[B mesons]] and thus a process in which matter and [[antimatter]] behave differently.<ref name=" Lohrmann_Söding_CC " /><ref name="cerncourier.com">Till Mundzeck: [https://cerncourier.com/a/the-three-lives-of-doris-from-charm-quarks-to-cell-biology/ "The three lives of DORIS: from charm quarks to cell biology"]. In: Cern Courier, 27 November 2012. Retrieved 23 December 2022.</ref> The most important discovery of the experiments [[TASSO]], [[JADE (particle detector)|JADE]], MARK-J and [[PLUTO detector|PLUTO]] at PETRA was the detection of the [[gluon]], the messenger particle of the [[strong force]], in 1979.<ref name=" Lohrmann_Söding_CC " /> From 1990, PETRA served as a pre-accelerator for the even larger [[storage ring]] HERA with its four experiments [[H1 (particle detector)|H1]], [[ZEUS (particle detector)|ZEUS]], [[HERMES experiment|HERMES]] and [[HERA-B]]. HERA was the only storage ring facility in the world in which [[proton]]s collided with electrons or [[positron]]s. In these collisions, the point-like electron acted like a probe, scanning the inner structure of the proton and making it visible with high resolution. HERA's precise insights into the interior of the proton formed the basis for numerous other particle physics experiments, especially at the [[Large Hadron Collider]] (LHC) at the research centre [[CERN]] and for numerous developments in theoretical particle physics.<ref name=" Lohrmann_Söding_CC " /><ref>Rolf-Dieter Heuer, Albrecht Wagner: [https://cerncourier.com/a/hera-leaves-a-rich-legacy-of-knowledge/ "HERA leaves a rich legacy of knowledge"]. In: Cern Courier, 21 January 2008. Retrieved 23 December 2022.</ref>

[[File:PETRA III Max von Laue Hall 2014.png|thumb|"Max von Laue" experimental hall at the synchrotron radiation source PETRA III on the DESY campus in Hamburg]]

In parallel, as early as the 1960s, research groups from DESY, various universities and the [[Max Planck Society]] developed the technology for using the [[synchrotron radiation]] produced by the accelerators.<ref>Thomas Heinze, Olof Hallonsten, Steffi Heinecke: "From periphery to center: Synchrotron radiation at DESY, Part I: 1962–1977". Historical Studies in the Natural Sciences 45, 447–492 (2015) [https://doi.org/10.1525/hsns.2015.45.3.447 DOI 10.1525/hsns.2015.45.3.447]</ref> To meet the rapidly growing national and European demand, DESY founded its own large laboratory: the Hamburg Synchrotron Radiation Laboratory HASYLAB, which opened in 1980.<ref>Thomas Heinze, Olof Hallonsten, Steffi Heinecke: "From periphery to center: Synchrotron radiation at DESY, Part II: 1977–1993". Historical Studies in the Natural Sciences 45, 513–548 (2015) [https://doi.org/10.1525/hsns.2015.45.4.513 DOI 10.1525/hsns.2015.45.4.513]</ref> It provided measuring stations at DORIS, and it was here that the Israeli biochemist [[Ada Yonath]] (Nobel Prize in Chemistry 2009) conducted experiments from 1986 to 2004 that led to her deciphering the [[ribosome]].<ref name=" Lohrmann_Söding_CC " /><ref name="cerncourier.com"/> From 1995, both synchrotron radiation and particle physics experiments were conducted at PETRA. In 2009, the PETRA facility was upgraded for exclusive use as a [[synchrotron light source|synchrotron radiation source]] for [[X-ray#energy ranges|hard X-rays]] (PETRA III).<ref name=" Lohrmann_Söding_CC " /> Today, PETRA III serves over 40 experimental stations, and there are plans to expand it into the PETRA IV 3D X-ray microscope.<ref>[https://www.wayforlight.eu/facility/20469 PETRA III at DESY]. In: www.wayforlight.eu. Retrieved 23 December 2022.</ref><ref>Christian Schroer et al.: "PETRA IV: the ultralow-emittance source project at DESY". In: J. Synchrotron Radiat. 25 (5), 1277–1290 (2019). Retrieved 23 December 2022. [https://doi.org/10.1107/S1600577518008858 DOI 10.1107/S1600577518008858].</ref> With the shutdown of DORIS in early 2013, the name HASYLAB was abandoned, and the use of DESY's light sources has since been carried out in its Photon Science division.

[[File: 2015-04-10 FLASH2 DN-MKX-4904.jpg |thumb|In the free-electron laser FLASH at DESY, electrons generate laser light in the soft X-ray range as they pass through special magnetic arrangements known as undulators (yellow).]]

In the early 1990s, DESY began to develop a new technology: [[radio frequency]] accelerator technology based on [[superconductivity|superconducting]] [[resonator#cavity resonators|cavities]] made of [[niobium]], which are cooled to approximately 2&nbsp;K (−271&nbsp;°C) with liquid [[helium]]. The first accelerator on this basis was a test facility for superconducting [[linear accelerator]]s at DESY to test the principle of [[self-amplified spontaneous emission]] (SASE) of X-ray laser light.<ref name="Jochen Schneider 2010">Jochen Schneider, Ilka Flegel: [https://cerncourier.com/a/flash-the-king-of-vuv-and-soft-x-rays/ "FLASH: the king of VUV and soft X-rays"]. In: CERN Courier, 30 November 2010. Retrieved 23 December 2022.</ref> The SASE theory was developed and refined at DESY and at institutes in Russia, Italy and the US from 1980 onwards.<ref>A.M. Kondratenko and E.L. Saldin: [https://s3.cern.ch/inspire-prod-files-8/872da099a0e9c171a4dca19256f7ca0e "Generation of Coherent Radiation by a Relativistic Electron Beam in an Ondulator"]. In: Part. Accelerators 10, 207–216 (1980). Retrieved 23 December 2022.</ref> In 2000 to 2001, the test facility at DESY was the first [[free-electron laser]] in the world to produce light flashes in the [[ultraviolet#Subtypes|vacuum ultraviolet]] and [[X-ray#energy ranges|soft X-ray]] range.<ref name="Jochen Schneider 2010"/> Today, the [[FLASH]] facility produces ultrashort light pulses in the soft X-ray range for seven experimental stations.<ref>[https://www.wayforlight.eu/facility/23603 FLASH at DESY]. In: wwwwayforlight.eu. Retrieved 23 December 2022.</ref> Since 2020, it has been expanded to further optimise the properties of the radiation (FLASH2020+ project).<ref>Ralf Röhlsberger et al.: "Light Source Upgrades at DESY: PETRA IV and FLASH2020+". In: Synchrotron Radiat. News 32 (1), 27–31 (2019). Retrieved 23 December 2022. [https://doi.org/10.1080/08940886.2019.1559605 DOI 10.1080/08940886.2019.1559605]</ref>

From 2009 to 2016, an international consortium led by DESY developed the European X-ray free-electron laser [[European XFEL]]. The international research facility, which involves 12 European shareholder countries, is operated by the non-profit company European XFEL [[GmbH]]. The core of the facility is a 1.7&nbsp;km superconducting linear accelerator. With an electron energy of 17.5&nbsp;GeV, it is the most powerful superconducting linear accelerator in the world to date. DESY operates the accelerator on behalf of European XFEL GmbH.<ref>[https://www.xfel.eu/facility/overview/desy/index_eng.html DESY and the European XFEL]. In: www.xfel.eu. Retrieved 23 December 2022.</ref><ref>Eric Beaurepaire, Fabrice Scheurer, Hervé Bulou, Jean-Paul Kappler (eds.): "Magnetism and Synchrotron Radiation", Springer, Berlin Heidelberg 2010, ISBN 9783642044984, p. 416.</ref>

Since 2010, DESY has been developing [[plasma acceleration|plasma-based accelerator technology]] (both laser- and electron-beam-driven) as a possible alternative to conventional accelerator technologies, with the aim of enabling compact accelerators for photon science, particle physics as well as medical and industrial applications.<ref>DESY: [https://www.desy.de/sites2009/site_www-desy/content/e410/e84441/e326618/Accelerators2021_ger.pdf Accelerators 2021. Highlights and Annual Report]. (PDF; 13 MB) In: www.desy.de. 1 May 2022. Retrieved 23 December 2022.</ref>

== Chairpersons of the DESY Directorate ==
DESY is headed by a Directorate consisting of the directors of the four divisions (Accelerators, Photon Science, Particle Physics and Astroparticle Physics) and the administration as well as the delegate of the Directorate for innovation. Chairpersons of the Directorate so far have been:<ref name=" Lohrmann_Söding_CC " />
* 1959 to 1970: [[Willibald Jentschke]], Founding Director
* 1971 to 1972: [[Wolfgang Paul]]
* 1973 to 1980: [[Herwig Schopper]]<ref>{{Citation |last1=Schopper |first1=Herwig |title=To DESY via CERN |date=2024 |work=Herwig Schopper |pages=95–117 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-031-51042-7_6 |isbn=978-3-031-51041-0 |last2=Gillies |first2=James|doi-access=free }}</ref>
* 1981 to 1993: Volker Soergel
* 1993 to 1999: [[Bjørn Wiik|Bjørn H. Wiik]]
* 1999 to early 2009: Albrecht Wagner
* 2009 to March 2025: Helmut Dosch
* since 1 April 2025: [[Beate Heinemann]]<ref>DESY press release from 31 March 2025 [https://www.desy.de/news/news_search/index_eng.html?openDirectAnchor=3724&two_columns=0/ "Beate Heinemann to lead DESY’s Board of Directors"]</ref>

== Joint research centres ==
[[File:CFEL-DESY Hamburg.jpg|thumb|Inside the Center for Free-Electron Laser Science (CFEL) in Hamburg]]

The DESY campus in Hamburg is the location of several national and international centres in which DESY participates. These are:<ref>German Federal Ministry of Education and Research (BMBF): [https://www.bmbf.de/bmbf/de/forschung/naturwissenschaften/grossgeraete/desy-deutsches-elektronen-synchrotron/deutsches-elektronen-synchrotron.html Deutsches Elektronen-Synchrotron – DESY] {{Webarchive|url=https://web.archive.org/web/20230124213549/https://www.bmbf.de/bmbf/de/forschung/naturwissenschaften/grossgeraete/desy-deutsches-elektronen-synchrotron/deutsches-elektronen-synchrotron.html |date=24 January 2023 }}. In: www.bmbf.de. Retrieved 23 December 2022 (in German).</ref>
* Center for Free-Electron Laser Science (CFEL): Investigation of ultrafast phenomena with free-electron lasers and optical lasers, studies of [[light–matter interaction]] under extreme conditions
* Centre for Structural Systems Biology (CSSB): Structural [[systems biology]] to study infection processes at the molecular level of viruses, bacteria and parasites
* Centre for X-ray and Nano Science (CXNS): Investigation of condensed matter with X-ray and complementary methods, high-resolution X-ray imaging, analysis of material processes

== Knowledge and technology transfer ==
[[File:2021-08-04 Start-up Labs Bahrenfeld MM-8624.jpg|thumb|The Start-up Labs Bahrenfeld, an innovation centre of DESY, the University of Hamburg and the Free and Hanseatic City of Hamburg were opened in September 2021.]]

DESY aims to promote start-ups and bring know-how from fundamental research into application. It offers commercial companies support for industrial issues, e.g. through special industry access to photon sources and laboratories, develops ideas, applications and products based on fundamental research, and supports its employees in founding start-ups based on DESY technologies in the Hamburg and Brandenburg regions. DESY offers start-ups access to offices, laboratories and workshops in the DESY Innovation Village and the Start-up Labs Bahrenfeld, established together with the [[University of Hamburg]] and the [[Free and Hanseatic City of Hamburg]].

== References ==
{{Portal|Physics|Hamburg}}
{{Reflist|30em}}

== External links ==
{{Commons category|DESY}}
* {{Official website|http://www.desy.de/index_eng.html}}

{{Synchrotron radiation facilities}}

{{Authority control}}

[[Category:Buildings and structures in Altona, Hamburg]]
[[Category:Education in Hamburg]]
[[Category:Free-electron lasers]]
[[Category:Organisations based in Hamburg]]
[[Category:Particle physics facilities]]
[[Category:Physics in Germany]]
[[Category:Physics research institutes]]
[[Category:Research institutes in Germany]]
[[Category:Synchrotron radiation facilities]]