CDC 28 11 2007
Status Report on the CDC from 28 November 2007
After 4 days of taking cosmic data it is time to look at some signals. Let's start by just showing the "raw" signals without any common mode noise (CMN) subtraction, a noisy signal is shown in figure 1, a "good" signal is shown in figure 2.
Lets compare this with the same signals but now with CMN subtraction, these are shown in figure 3 (noisy signal) and 4 ("good" signal).
What can be seen: 1/ for the noise signal the CMN subtraction does a good job, it significantly reduces the noise and the quality of the signal, fitting a straight line to the edge of the signal will be easier. 2/ the same can be said for the "good" signal but the impact there is less pronounced. 3/ The negative part in the corrected "good" signal is due to signals in other channels which are included in the CMN subtraction - this also causes a decrease in amplitude of the signal shown. We could solve this by only include channels in the CMN subtraction that do not contain a signal. 4/ The edge of the signal consists of 4-6 channels, which means 2-3 channels if we use the 100 MHz fADC.
