CALICE DHCAL Noise Analysis

This note reports on the preliminary results of noise measurements of the CALICE DHCAL prototype during the beam tests at Fermilab. The noise level of the RPC’s are monitored on a day-by-day basis with self-triggered noise runs. The average noise rate for the RPC’s is around 1 Hz/cm2, and it translates to about 0.1 noise hit per triggered beam event. Some long randomly triggered noise studies are also performed, and the results are compared with the self-triggered noise runs. During the beam tests, we observed noisy regions in some RPC’s. A study of possible reasons for this elevated noise rate is presented. This note also includes an account of the malfunctioning ASIC’s during the beam tests.