Editing Compact Linear Collider (section)

== CLIC detector ==
[[File:CLIC detector.jpg|thumb|CLIC detector with cut out and labels |alt=|280x280px]]
A state-of-the-art [[detector]] is essential to profit from the complete physics potential of CLIC. The current detector design, named CLICdet, has been optimised via full [[simulation]] studies and R&D activities.<ref name="Alipour_CERN-2017">
{{cite report
 |editor1-last=Alipour Tehrani |editor1-first=N.
 |display-editors=etal 
 |id=CLICdp-Note-2017-001
 |url=https://cds.cern.ch/record/2254048/files/CLICdp-Note-2017-001.pdf
 |title= CLICdet: The post-CDR CLIC detector model
 |location=Geneva, Switzerland
 |year=2017
}}</ref><ref name=clicdet_validation>
{{cite arXiv |eprint=1812.07337 |collaboration=The CLICdp collaboration |title=A detector for CLIC: Main parameters and performance |class=physics.ins-det |year=2018 |last1=Arominski |first1=D. |last2=Blaising |first2=Jean-Jacques |last3=Brondolin |first3=Erica |last4=Dannheim |first4=Dominik |last5=Elsener |first5=Konrad |last6=Gaede |first6=Frank |last7=García-García |first7=Ignacio |last8=Green |first8=Steven |last9=Hynds |first9=Daniel |last10=Leogrande |first10=Emilia |last11=Linssen |first11=Lucie |last12=Marshall |first12=John |last13=Nikiforou |first13=Nikiforos |last14=Nürnberg |first14=Andreas |last15=Perez-Codina |first15=Estel |last16=Petrič |first16=Marko |last17=Pitters |first17=Florian |last18=Robson |first18=Aidan |last19=Roloff |first19=Philipp |last20=Sailer |first20=André |last21=Schnoor |first21=Ulrike |last22=Simon |first22=Frank |last23=Simoniello |first23=Rosa |last24=Spannagel |first24=Simon |last25=Ström |first25=Rickard |last26=Viazlo |first26=Oleksandr |last27=Weber |first27=Matthias |last28=Xu |first28=Boruo}}</ref><ref
name="detector_R_and_D">
{{cite journal |last1=Dannheim |first1=Dominik |last2=Krüger |first2=Katja |last3=Levy |first3=Aharon |last4=Nürnberg |first4=Andreas |last5=Sicking |first5=Eva |title=Detector Technologies for CLIC |journal=CERN Yellow Reports: Monographs |date=2019 |volume=1 |doi=10.23731/CYRM-2019-001 |bibcode=2019arXiv190502520A |arxiv=1905.02520 |s2cid=146808208
}}</ref> The detector follows the standard design of grand particle detectors at high energy colliders: a cylindrical detector volume with a layered configuration, surrounding the beam axis. CLICdet would have dimensions of ~13&nbsp;×&nbsp;12&nbsp;m (height × length) and weigh ~8000 tonnes.

=== Detector Layers ===
CLICdet consists of four main layers of increasing radius: vertex and tracking system, [[calorimeters]], [[solenoid]] [[magnet]], and [[muon]] detector.<ref name="Alipour_CERN-2017" />
[[File:Compact Linear Collider CLICTD.tif|alt=|thumb|280x280px|A silicon pixel detector prototype for CLIC: "CLICTD" – a monolithic CMOS chip containing both sensor and readout, shown here on an electronics board during testing]]
The vertex and tracking system is located at the innermost region of CLICdet and aims to detect the position and momenta of particles with minimum adverse impact on their [[energy]] and [[trajectory]]. The vertex detector is cylindrical with three double layers of detector materials at increasing radii and has three segmented disks at each end in a spiral configuration to aid air flow cooling. These are assumed to be made of 25x25 μm2 silicon pixels of thickness 50&nbsp;μm, and the aim is to have a single point resolution of 3&nbsp;μm. The tracking system is made of [[silicon]] [[sensor]] modules expected to be 200&nbsp;μm thick.<ref name=Alipour_CERN-2017/>

The calorimeters surround the vertex and tracking system and aim to measure the energy of particles via absorption. The electromagnetic calorimeter (ECAL) consists of ~40 layers of silicon/tungsten in a sandwich structure; the hadronic calorimeter (HCAL) has 60 [[steel]] absorber plates with [[scintillation (physics)|scintillating]] material inserted in between.<ref name="Alipour_CERN-2017" />

These inner CLICdet layers are enclosed in a superconducting solenoid magnet with a field strength of 4 [[tesla (unit)|T]]. This magnetic field bends charged particles, allowing for [[momentum]] and [[electric charge|charge]] measurements. The magnet is then surrounded by an [[iron]] yoke which would contain large area detectors for muon identification.<ref name="Alipour_CERN-2017" />

The detector also has a luminosity calorimeter (LumiCal) to measure the products of [[Bhabha scattering]] events, a beam calorimeter to complete the ECAL coverage down to 10 {{not a typo|mrads}} polar angle, and an intra-train feedback system to counteract luminosity loss due to relative beam-beam offsets.<ref name="Alipour_CERN-2017" />

=== Power pulsing and cooling ===
[[File:CLIC gas cooling vertex.png|thumb|Gas-cooling vertex streamlines|alt=|280x280px]]Strict requirements on the material budget for the vertex and tracking system do not allow the use of conventional [[liquid]] cooling systems for CLICdet. Therefore, it is proposed that a dry gas cooling system will be used for this inner region. Air gaps have been factored into the design of the detector to allow the flow of the [[gas]], which will be air or [[Nitrogen]].<ref name=Duarte-Ramos_Klempt_Nuiry_CLIC_CERN-2016>
{{cite report
 |editor1-last=Duarte Ramos|editor1-first=F.
 |editor2-last=Klempt|editor2-first=W.
 |editor3-last=Nuiry|editor3-first=F. -X.
 |id=CLICdp-Note-2016-002
 |url=https://cds.cern.ch/record/2138963/files/CLICdp-Note-2016-002_14-03-16.pdf
 |title= Experimental tests on the air cooling of the CLIC vertex detector
 |location=Geneva, CERN
 |year=2016
}}</ref><ref name="Duarte-Ramos_Gerwig_Villajero-Bermudez_CLIC_CERN-2014">
{{cite report
 |editor1-last=Duarte Ramos|editor1-first=F.
 |editor2-last=Gerwig|editor2-first=H.
 |editor3-last=Villajero Bermudez|editor3-first=M.
 |id=LCD-Note-2013-007
 |title= CLIC inner detectors cooling simulations
 |url=https://cds.cern.ch/record/1572989/files/LCD-Note-2013-007.pdf
 |location=Geneva, Switzerland
 |collaboration=CERN Linear Collider Detector collaboration
 |year=2014
}}</ref> To allow for effective air cooling, the average power consumption of the Silicon sensors in the vertex detector needs to be lowered. Therefore, these sensors will operate via a current-based power pulsing scheme: switching the sensors from a high to low power consumption state whenever possible, corresponding to the 50&nbsp;Hz bunch train crossing rate.<ref name="Blanchot_Dannheim_Fuentes_CLIC_CERN-2014">{{cite journal
 |last1=Blanchot|first1=G
 |last2=Dannheim|first2=D
 |last3=Fuentes|first3=C
 |title=Power-pulsing schemes for vertex detectors at CLIC
 |journal=Journal of Instrumentation
 |volume=9
 |issue=1
 |year=2014
 |pages=C01005
 |doi=10.1088/1748-0221/9/01/C01005 |doi-access=free
 |bibcode=2014JInst...9C1005B
}}</ref>