R. Zitoun, Stony Brook and LAPP Cal Meeting July 15, 20031

• 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

Noisy ad nausea?Robert Zitoun

Stony Brook and LAPP Cal MeetingJuly 15, 2003

R. Zitoun, Stony Brook and LAPP Cal Meeting July 15, 20032

Noisy ADC cards• ADC cards cover 8 BLS boards/trigger tower

• CC: 0<||<1.2 × 4 lines in (not all)

• EC: 1.2<||<4.5 × 4 lines in (not all)

R. Zitoun, Stony Brook and LAPP Cal Meeting July 15, 20033

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 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 July 15, 20034

ADC Card Occupancy• Find the occupancy for all 144 cards in the event

• Find the highest occupancy

cut at 0.5

R. Zitoun, Stony Brook and LAPP Cal Meeting July 15, 20035

Energy in highly occupied Cards• Compute <ADCi> and rms(ADCi) for cells in cards with

(individual) occupancy > 50 %

<ADCi>

rms(

AD

Ci)

all events

R. Zitoun, Stony Brook and LAPP Cal Meeting July 15, 20036

Zoo

R. Zitoun, Stony Brook and LAPP Cal Meeting July 15, 20037

More Zoo

↓ Negative cells ↓

R. Zitoun, Stony Brook and LAPP Cal Meeting July 15, 20038

To be continued...• 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

ECN CC ECS CC ECN