Author: Matis, H.S.
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MOP202 Simulations of the LHC High Luminosity Monitors at Beam Energies 3.5 TeV to 7.0 TeV 471
 
  • H.S. Matis, P. Humphreys, A. Ratti, W.C. Turner
    LBNL, Berkeley, California, USA
  • R. Miyamoto
    BNL, Upton, Long Island, New York, USA
  • J. Stiller
    Heidelberg University, Heidelberg, Germany
 
  Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
We have constructed two pairs of fast ionization chambers (BRAN) for measurement and optimization of luminosity at IR1 and IR5 of the LHC. These devices are capable of monitoring the performance of the LHC at low luminosity 1028 cm-2s−1 during beam commissioning all the way up to the expected full luminosity of 1034 cm-2s−1 at 7.0 TeV. The ionization chambers measure the intensity of hadronic/electromagnetic showers produced by the forward neutral particles of LHC collisions. To predict and improve the understanding of the BRAN performance, we created a detailed FLUKA model of the detector and its surroundings. In this paper, we describe the model and the results of our simulations including the detector’s estimated response to pp collisions at beam energies of 3.5, 5.0, and 7.0 TeV per beam. In addition, these simulations show the sensitivity of the BRAN to the crossing angle of the two LHC beams. It is shown that the BRAN sensitivity to crossing angle is proportional to the measurement of crossing angle by the LHC beam position monitors.
 
 
WEOCN3 Operational Results from the LHC Luminosity Monitors 1443
 
  • R. Miyamoto
    BNL, Upton, Long Island, New York, USA
  • E. Bravin
    CERN, Geneva, Switzerland
  • H.S. Matis, A. Ratti, W.C. Turner, H. Yaver, T. stezelberger
    LBNL, Berkeley, California, USA
 
  Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
The Luminosity Monitors for the high luminosity regions in the LHC have been operating to monitor and optimize the luminosity since the beginning of the 2009 run. The device is a gas ionization chamber, which has the ability to resolve bunch-by-bunch luminosity as well as survive the extreme levels of radiation at nominal high intensity LHC operations. The chambers are installed at the zero degree collision angle inside the neutral absorbers 140 m from the interaction point and monitor showers produced by high energy neutral particles from the collisions. A second device, a photo-multiplier based system (PMT) located directly behind the gas ionization chamber, has been also used at low luminosities. We will present operational results for the ionization chambers for both pp and Pb-Pb collisions. These measurements include signal, noise and background studies, and correlation between the gas ionization detector and the PMT. Also, comparison with ongoing modeling efforts will be included.
 
slides icon Slides WEOCN3 [2.609 MB]