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dc.contributor.advisorBernd Surrow.en_US
dc.contributor.authorMcGehee, William Ren_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Physics.en_US
dc.date.accessioned2009-03-20T19:31:17Z
dc.date.available2009-03-20T19:31:17Z
dc.date.copyright2008en_US
dc.date.issued2008en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/44910
dc.descriptionThesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2008.en_US
dc.descriptionThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.en_US
dc.descriptionIncludes bibliographical references (p. 69).en_US
dc.description.abstractThis thesis details the motivation, design, construction, and testing of the Gamma Intensity Monitor (GIM) for the Crystal-Barrel-Experiment at the Universität Bonn. The CB-ELSA collaboration studies the baryon excitation spectrum; resonances are produced by exciting nucleons in a polarized target with a linearly or circularly polarized, GeV-order photon beam. The photoproduced decay states are measured by a variety of detectors covering almost 4[pi] of the solid angle about the target. To measure the total cross section of these reactions, the total flux of photons through the target must be known to high accuracy. As the total cross section for nuclear photoproduction is low, counting the photons unscattered in the target is sufficiently accurate measurement of this quantity{this is the purpose of the Gamma Intensity Monitor. It is the final detector along the beam path and counts all photons that do not react with the target. The major design parameter is that the detector must consistently count GeV order photons at 10 MHz. This is accomplished by allowing the gammas to electronpositron pair produce within Ĉerenkov radiating PbF2 crystals. The Cerenkov light from these highly relativistic lepton pairs is measured with industrial photomultiplier tubes to provide an effective efficiency close to unity. Special bases were built for photomultiplier to ensure stable signal amplication even high count rates. Detailed descriptions of the GIM are provided to ensure that its inner working are completely transparent and to enable efficient operation and maintenance of the detector.en_US
dc.description.statementofresponsibilityby William R. McGehee.en_US
dc.format.extent69 p.en_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectPhysics.en_US
dc.titleThe Gamma Intensity Monitor at the Crystal-Barrel-Experimenten_US
dc.typeThesisen_US
dc.description.degreeS.B.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Physics.en_US
dc.identifier.oclc298256559en_US


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