HV Report

Below is a plot showing the channel-by-channel ratio of ADC counts in runs 217564 after replacement of preamps and run 216345 taken before preamp replacement.

From this plot, I identified 27 "newly dead" channels. They are listed in Table 1. Twelve of these channels are in drawers NW4 and SW1, neither of which were installed at the time of the run.

Taking the ADC coordinates from the plot, I used Alan Stone's hardware map to determine the ieta and iphi and drawer. Next, I cross-referenced this withe the list of PMTs that I had asked Naveen to pull. The newly dead channels and Naveen's list are positively correlated when using the mapping in Table 2, except for 2 channels that appear to be dead for independent reasons.

Reading the PMT id numbers from Alan's map (Column "Expected PMT" in Table 1), I cross referenced this with the PMT id numbers Naveen recorded as he removed the PMTs (Column "Recorded PMT" in Table 1). None of the 15 tubes were positively correlated.

Finally, I navigated the map using the recorded PMT id numbers, and made a note of the expected location of that PMT (Column "Design Coords" in Table 1).

This study indicates that the PMTs were installed wrong throughout the entire ICD.