CDC Pedestal Studies

Pedestal Subtraction

Based on cosmic ray data with BCAL trigger Look for events with the following signature in the CDC:

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The first test was done by using the region $P_{{i}}$ (blue) to determine a pedestal and the region I (red) to determine an Integral and then subtract the proper pedestal from the Intergral as follows: $D=I-P_{{i}}/N_{{i}}*80.$ where $N_{{i}}$ is the number of samples used to calculate the pedestal and 80 is the number of samples in the Integral I. In the case of no signal the the distribution D is expected to be around zero with a sigma that reflects the resolution and depends on the number samples $N_{{i}}$ used in determining the pedestal. As an example the distribution with 4 samples in the pedestal calculation looks like this:

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$N_{{i}}$	mean F	sigma F	mean I	sigma I
4	102.2	1293	96.5	1276
16	119.0	1121	163.4	1120
20	121.1	1080	145.1	1080
32	102.4	984	159.0	978
64	40.9	680	84.6	685