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Title: Double side read-out technique for mitigation of radiation damage effects in PbWO 4 crystals

Test beam results of a calorimetric module based on 3×3×22 cm 3 PbWO 4 crystals, identical to those used in the CMS ECAL Endcaps, read out by a pair of photodetectors coupled to the two opposite sides (front and rear) of each crystal are presented. Nine crystals with different level of induced absorption, from 0 to 20 m -1, have been tested using electrons in the 50–200 GeV energy range. Photomultiplier tubes have been chosen as photodetectors to allow for a precise measurement of highly damaged crystals. The information provided by this double side read-out configuration allows to correct for event-by-event fluctuations of the longitudinal development of electromagnetic showers. By strongly mitigating the effect of non-uniform light collection efficiency induced by radiation damage, the double side read-out technique significantly improves the energy resolution with respect to a single side read-out configuration. The non-linearity of the response arising in damaged crystals is also corrected by a double side read-out configuration and the response linearity of irradiated crystals is restored. In high radiation environments at future colliders, as it will be the case for detectors operating during the High Luminosity phase of the Large Hadron Collider, defects can be created inside themore » scintillator volume leading to a non-uniform response of the calorimetric cell. As a result, the double side read-out technique presented in this study provides a valuable way to improve the performance of calorimeters based on scintillators whose active volumes are characterized by high aspect ratio cells similar to those used in this study.« less
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [9] ;  [10] ;  [11] ;  [12] ;  [7]
  1. European Organization for Nuclear Research (CERN), Geneva (Switzerland)
  2. INFN Sezione di Roma and Sapienza Univ. di Roma, Roma (Italy)
  3. STFC Rutherford Appleton Lab., Didcot (United Kingdom)
  4. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  5. DEA/IRFU, Gif-sur-Yvette (France)
  6. Russian Academy of Sciences, Moscow (Russia)
  7. Brunel Univ., Middlesex (United Kingdom)
  8. National Central Univ., Taoyuan City (Taiwan)
  9. Byelorussian State Univ., Minsk (Belarus)
  10. Univ. of Minnesota, Minneapolis, MN (United States)
  11. Univ. of Milano-Bicocca, Milano (Italy)
  12. Helmholtzzentrum fur Schwerionenforschung GmbH, Darmstadt (Germany)
Publication Date:
Report Number(s):
Journal ID: ISSN 1748-0221; 1450049
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Instrumentation
Additional Journal Information:
Journal Volume: 11; Journal Issue: 04; Journal ID: ISSN 1748-0221
Institute of Physics (IOP)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; calorimeter methods; calorimeters; radiation damage to detector materials (solid state); radiation-hard detectors
OSTI Identifier: