Author: Dabrowski, A.E.
Paper Title Page
MOCL2 Design of a Novel Cherenkov Detector System for Machine Induced Background Monitoring in the CMS Cavern 33
  • S. Orfanelli, A.E. Dabrowski, M. Giunta
    CERN, Geneva, Switzerland
  • M.J. Ambrose, A. Finkel, R. Rusack
    University of Minnesota, Minneapolis, Minnesota, USA
  • D.P. Stickland
    PU, Princeton, New Jersey, USA
  A novel detector system has been designed for an efficient online measurement of the machine induced background in the CMS experimental cavern. The suppression of the CMS cavern background originating from pp collision products and the 25 ns bunch spacing have set the requirements for the detector design. Each detector unit will be a radiation hard, cylindrical Cherenkov radiator optically coupled to an ultra-fast UV-sensitive photomultiplier tube, providing a prompt, directionally sensitive measurement. Simulation and test beam measurements have shown the achievability of the goals that have driven the baseline design. The system will consist of 20 azimuthally distributed detectors per end, installed at a radius of r ~ 180 cm and a distance 20.6 m away from the CMS interaction region. The detector units will enable a measurement of the transverse distribution of the bunch-by-bunch machine induced background flux. This will provide important feedback from the CMS on the beam conditions during the LHC machine setup and comparisons to expectations based on FLUKA simulations.  
slides icon Slides MOCL2 [14.094 MB]  
MOPC43 Performance of Detectors using Diamond Sensors at the LHC and CMS 174
  • M. Hempel
    BTU, Cottbus, Germany
  • T. Baer, A.E. Dabrowski
    CERN, Geneva, Switzerland
  • E. Griesmayer
    ATI, Wien, Austria
  • W. Lange, O. Novgorodova
    DESY Zeuthen, Zeuthen, Germany
  • W. Lohmann
    DESY, Hamburg, Germany
  • N.J. Odell
    NU, Evanston, USA
  • D.P. Stickland
    PU, Princeton, New Jersey, USA
  Diamond detectors are used as beam loss and luminosity monitors for CMS and LHC. A time resolution in the nanosecond range allows to detect beam losses and luminosities of single bunches. The radiation hardness and negligible temperature dependence allow the usage of diamond sensors in high radiation fields without cooling. Two different diamond detector types are installed at LHC and CMS. One is based on pCVD diamonds and installed at different locations in the LHC tunnel for beam loss monitoring. Measurements of these detectors are used to perform a bunch-by-bunch beam loss analysis. They allow to disentangle the origin of beam losses. The second type uses sCVD diamonds and is located inside CMS for van-der-Meer scan, beam halo and online luminosity monitoring and around the LHC tunnel for beam loss observation. Results on the performance of these detectors will be presented and examples of the use for analyzing the beam conditions will be given. In order to persist the enhanced requirements of the LHC after the long shutdown, e.g. higher luminosity, an upgrade of the detectors is required. The concept of the new detectors will be presented and first results will be shown.  
poster icon Poster MOPC43 [0.721 MB]