• Main INDEX
  • Monthly INDEX
  • PREV
  • NEXT
    Make New Entry, Make Followup Entry

    User name flay

    Log entry time 14:50:34 on March 10, 2009

    Entry number 265554

    keyword=LHRS Gas Cerenkov

    I've been working on the calibration of the pion rejector, and looking at the Cerenkov, I have noticed some strange behavior. In figure 1, you will see a sharp peak at ~5000 channels for each PMT. This shows up in the Cerenkov sum plot as a broad distribution around channel 5000. Patricia pointed out to me that this signal is for those particles that do not trigger the Cerenkov, but rather are particles that trigger the other detectors. So this peak is a matter of book keeping of all events that trigger at least one detector. My concern is that this peak is not consistent for all the individual PMTs. I have a feeling that this may hinder some events at the higher end of the spectrum. To account adjust for this, I made a plot (see Figure 2) of the Cerenkov sum with cuts on those peaks for each individual PMT (shown in blue). This I consider to be the 'true' Cerenkov spectrum.

    Is there any way of adjusting this peak to be consistent with all PMTs at a much higher channel, so that it won't affect the true statistics?

    A copy of this log entry has been emailed to: meziani,brads,posik



    Figure 1

    cer_indiv_chain.ps

    Figure 2

    cer_sum_chain_cer-indiv_cut.ps