- Zeus (particle detector)
ZEUS is a
particle detector that was operation at HERA ("Hadron Elektron Ring Anlage ") inDESY ,Hamburg . It began operating together with HERA in1992 and was functional until HERA was decommissioned in June 2007.Leptons (electron s orpositron s) were collided withproton s by HERA in theinteraction point of ZEUS. ZEUS was operated by an international collaboration of about 400physicist s from 42institute s in 15 countries. The ZEUSdetector comprises many components, including a depleteduranium -plastic scintillatorcalorimeter , a Central Tracking Detector, which is awire chamber , asilicon microvertex detector and muon chambers. In addition asolenoid provides a 1.43 Tmagnetic field . The ZEUS experiment studies the internal structure of theproton through measurements ofdeep inelastic scattering . These measurements are also used to test and study theStandard Model ofparticle physics , as well as searching for particles beyond the Standard Model.Background
DESY was founded in 1959 and started colliding electron beams in 1964 in the DESY experiment. Since then, it has been a highly regarded centre for Particle Physics. TheHERA collider began operation in 1992. The design effort for ZEUS can be traced back to 1982 Fact|date=May 2008. The last electron-proton collisions at ZEUS were recorded at approximately 11:20 p.m CET on June 30th 2007. The ZEUS detector is now in the process of being decommissioned and dismantled.Detector
The ZEUS detector is comprised of many components The ZEUS Detector: Status Report 1993 http://www-zeus.desy.de/bluebook/bluebook.html] . The purpose of the ZEUS detector is to reconstruct physics events in a consistent way so they can be analyzed. The main components of the ZEUS detector are the Tracking Components, The Calorimeter and the Muon Detectors.
Calorimeter
The ZEUS calorimeter is a
Uranium -Scintillator sampling calorimeter and is divided into 3 main sections the BCAL (Barrel CALorimeter), FCAL (Forward CALorimeter) and RCAL (Rear CALorimeter). Each section is subdivided transversely into towers and longitudinally into EMC (Electro-Magnetic Calorimeter) or HAC (HAdronic Calorimeter). The smallest sub division in the calorimeter is called a Cell. Each cell is read-out by two photomultiplier tubes, this redundancy helps to ensure that there are no holes in the detector if a PMT fails.Uranium was chosen as an absorber because of its ability to compensate.
Leptons (andphoton s) andHadron s deposit energy differently than each other. In general the proportion of energy deposited from an Electromagnetic Cascade (e) is different from that in Hadronic Cascade (h). In most Physics experiments e/h > 1 which compromises the energy measurement. In the ZEUS calorimeter SubatomicParticle|link=yes|Pion0s interact with Uraniumatoms to produce slow movingneutron s which are captured by the scintillator and increase the hadronic signal. Another advantage of using Uranium as the absorber is that the natural radioactivity allows one to monitor the calibration of the experiment over time.Notes
External links
* [http://www-zeus.desy.de/ http://www-zeus.desy.de/ - Official homepage]
* [http://www-zeus.desy.de/zeus_papers/zeus_papers.html List of Publications]
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