Cosmics Checkout

This work done by Rupesh Silwal, Dustin McNulty, Bob Michaels, Kent Pashke:

• Use cosmic rays to checkout the condition of the HAPPEX detectors, BugsBunny (BB) and DaffyDuck (DD), along the entire 1.5m length of their acrylic/lead sandwiches.
• Setup cosmic trigger (using paddles from Bogdan) and the right HRS DAQ to take data. Trigger was setup for cosmic rays passing at 45 degree angle through detector at various distances from the PMT.
• We used the PMT labelled "Jack" for both the BB and DD detectors.
• Typical runs (at each trigger position) last between 12 and 24 hours with an event rate of about 6000 total events/24 hrs. Of the 6000 total events, ~1200 (or 20%) pass the trigger cuts.

Example ADC distribution for BB/Jack. Note the odd shaped pedestal.

Signal size versus Distance from PMT (BB/Jack). Slope is 0.23% change in signal size per cm. This corresponds to a 35% difference in signal size from one end to the other.