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The 0.22 MIP cut only applies when there is a track pointing to the tile. Such an event is less likely to be backsplash and so we are interested only in the charged particle efficiency at this cut, not the low energy spectrum efficiency. Below is a histogram of the charged particle veto efficiencies for a veto at 0.22 MIPs. The average efficiency is 0.9976. Two PMTs (0_210 and 1_423) are not included because the histograms are too messy to find reasonable efficiencies. Over 93% 91% (164161/176) of the PMTs have efficiencies within error of above 0.995 and 34.6% 25% (6144/176) have efficiencies within error of above 0.999.
0.44 MIP Efficiency
Below are the histograms of the charged particle and low energy spectrum efficiencies for a veto at 0.44 MIPs. The mean efficiencies are 0.9835 for the charged particles and 0.9544 for the low energy spectrum. The average error on the low energy spectrum efficiency increases as the veto threshold rises, and at 0.44 MIPs is about 0.01.
