Potential HV change vi_B --> ? towers only
  • HV used : set vi_B
  • 300K minB events, details of slopes extraction.
  • PDF for all 12 eta bins.
    Left: slopes vs. phi. Black towers with slopes differing by 5%+ from the average
    Right: weighted, truncated distribution of slops & fit.


    GAIN CHANGE between HV set vi_B -->iv_B
    etaBin set iv_A
    avrSlope (RMS)
    set iv_A
    avrSlope (RMS)
    achieed
    gainB/gainA
    intended
    gainB/gainA
    delta
    1 -0.152 (0.010) -0.152 (0.0089) 1.000 1.00 0%
    2 -0.146 (0.007) -0.144 (0.009) 1.014 1.00 +1.4%
    3 -0.144 (0.0084) -0.143 (0.007) 1.007 1.00 +0.7%
    4 -0.146 (0.0086) -0.144 (0.0065) 1.013 1.00 +1.3%
    5 -0.146 (0.0079) -0.141 (0.0073) 1.035 1.081 -4.6%
    6 -0.144 (0.0078) -0.137 (0.0062) 1.051 1.096 -4.5%
    7 -0.141 (0.0090) -0.132 (0.0069) 1.068 1.104 -3.6%
    8 -0.139 (0.0078) -0.134 (0.0056) 1.037 1.049 -1.2%
    9 -0.136 (0.0084) -0.128 (0.0063) 1.063 1.062 +0.1%
    10 -0.130 (0.0077) -0.122 (0.0064) 1.066 1.080 -1.4%
    11 -0.123 (0.0059) -0.118 (0.0057) 1.042 1.046 -0.4%
    12 -0.125 (0.0073) -0.112 (0.0058) 1.116 1.135 -1.9%

    Conclusions

  • the overal gain change was in the correct direction. We undershoot a bit. With avaliable accuracy of ~1-2% we can say current gains are at 60GeV maxET for all eta bins except bins 5-7, where we may still have absolute gains too low by ~3%.
  • there is ~10 individual towers for which it would make sense to change HV (see previous page.)
  • to improve staistical accuracy of indvidual slopes below ~5% -->3% we need 1M minB events.