Editing Beryllium (section)

===Radiation windows===
[[File:Beryllium target.jpg|thumb|Beryllium target which converts a proton beam into a neutron beam]]
[[File:Be foil square.jpg|thumb|right|A square beryllium foil mounted in a steel case to be used as a window between a vacuum chamber and an [[X-ray microscope]]. Beryllium is highly transparent to X-rays owing to its low [[atomic number]].]]
Because of its low atomic number and very low absorption for X-rays, the oldest and still one of the most important applications of beryllium is in radiation windows for [[X-ray tube]]s.{{sfn|Emsley|2001|p=58}} Extreme demands are placed on purity and cleanliness of beryllium to avoid artifacts in the X-ray images. Thin beryllium foils are used as radiation windows for X-ray detectors, and their extremely low absorption minimizes the heating effects caused by high-intensity, low energy X-rays typical of [[synchrotron]] radiation. Vacuum-tight windows and beam-tubes for radiation experiments on synchrotrons are manufactured exclusively from beryllium. In scientific setups for various X-ray emission studies (e.g., [[energy-dispersive X-ray spectroscopy]]) the sample holder is usually made of beryllium because its emitted X-rays have much lower energies (≈100&nbsp;eV) than X-rays from most studied materials.<ref name="Behrens-2003" />

Low [[atomic number]] also makes beryllium relatively transparent to energetic [[Elementary particle|particles]]. Therefore, it is used to build the [[beamline|beam pipe]] around the collision region in [[particle physics]] setups, such as all four main detector experiments at the [[Large Hadron Collider]] ([[A Large Ion Collider Experiment|ALICE]], [[ATLAS experiment|ATLAS]], [[Compact Muon Solenoid|CMS]], [[LHCb]]),<ref>{{Cite web|title =Installation and commissioning of vacuum systems for the LHC particle detectors|publisher =CERN|first1 =R.|last1 =Veness|first2 =D.|last2 =Ramos|first3 =P.|last3 =Lepeule|first4 =A.|last4 =Rossi|first5 =G.|last5 =Schneider|first6 =S.|last6 =Blanchard|url =http://accelconf.web.cern.ch/accelconf/PAC2009/papers/mo6rfp010.pdf|access-date =13 January 2012|archive-date =14 November 2011|archive-url =https://web.archive.org/web/20111114063409/http://accelconf.web.cern.ch/accelconf/PAC2009/papers/mo6rfp010.pdf|url-status =live}}</ref> the [[Tevatron]] and at [[SLAC]]. The low density of beryllium allows collision products to reach the surrounding detectors without significant interaction, its stiffness allows a powerful vacuum to be produced within the pipe to minimize interaction with gases, its thermal stability allows it to function correctly at temperatures of only a few degrees above [[absolute zero]], and its [[diamagnetic]] nature keeps it from interfering with the complex multipole magnet systems used to steer and [[strong focusing|focus]] the [[particle beam]]s.<ref>{{Cite journal|doi=10.1016/S0168-9002(01)01149-4|title=A new inner vertex detector for STAR|date=2001|author=Wieman, H|journal=Nuclear Instruments and Methods in Physics Research Section A|volume=473|issue=1–2|page=205|bibcode=2001NIMPA.473..205W|last2=Bieser|first2=F.|last3=Kleinfelder|first3=S.|last4=Matis|first4=H. S.|last5=Nevski|first5=P.|last6=Rai|first6=G.|last7=Smirnov|first7=N.|s2cid=39909027 |url=https://digital.library.unt.edu/ark:/67531/metadc786424/m2/1/high_res_d/860449.pdf|access-date=30 October 2021|archive-date=17 October 2020|archive-url=https://web.archive.org/web/20201017190110/https://digital.library.unt.edu/ark:/67531/metadc786424/m2/1/high_res_d/860449.pdf|url-status=live}}</ref>