Noisy ad nausea?

1. Noisy ad nausea? • Yuri very upset with noisy events screwing his analysisProvided tens of event displays with bad features • Bob sees differences between trigger and precision energies • Use runs around 174500 Robert Zitoun Stony Brook and LAPP Cal Meeting July 15, 2003 R. Zitoun, Stony Brook and LAPP Cal Meeting

2. Noisy ADC cards • ADC cards cover 8 BLS boards/trigger tower • CC: 0<|h|<1.2 × 4 lines in j (not all) • EC: 1.2<|h|<4.5 × 4 lines in j (not all) R. Zitoun, Stony Brook and LAPP Cal Meeting

3. How to Catch Those? • Assumption • coherent noise for all 384 channels read by the same ADC card • same value in ADC counts • Method: tag cards with • high occupancy • low energy per channel • low rms among channels • Method • go back from E to ADC counts • look only at EM channels (HAD have higher noise, thus zero suppressed) • don’t consider high h cells (>3.3) • count no of cells with energy per ADC card and compute occupancy (wrt no of EM channels) R. Zitoun, Stony Brook and LAPP Cal Meeting

4. ADC Card Occupancy cut at 0.5 • Find the occupancy for all 144 cards in the event • Find the highest occupancy R. Zitoun, Stony Brook and LAPP Cal Meeting

5. Energy in highly occupied Cards all events rms(ADCi) <ADCi> • Compute <ADCi> and rms(ADCi) for cells in cards with (individual) occupancy > 50 % R. Zitoun, Stony Brook and LAPP Cal Meeting

6. Zoo R. Zitoun, Stony Brook and LAPP Cal Meeting

7. More Zoo ↓ Negative cells ↓ R. Zitoun, Stony Brook and LAPP Cal Meeting

8. To be continued... ECN CC ECS CC ECN • Localization of bad “cards” • Same patterns with recent runs • Same pattern if 0.4<occupancy<0.5 (less pronounced) even less for 0.35<occupancy<0.4 R. Zitoun, Stony Brook and LAPP Cal Meeting