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CSC Digitization. Rick Wilkinson. CSC design and readout. Large chambers Wires groups: 5 cm wide Cathode strips: 8-16 mm wide. wire-group hits every 25 ns same information for trigger/offline. 3.3 m. Level-1 Trigger: half-strip hits every 25 ns
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CSC Digitization Rick Wilkinson
CSC design and readout • Large chambers • Wires groups: 5 cm wide • Cathode strips: 8-16 mm wide wire-group hits every 25 ns same information for trigger/offline 3.3 m Level-1 Trigger: half-strip hits every 25 ns HLT*/offline: 12-bit digitization every 50 ns *HLT – High Level Trigger
Code Structure Ionize, Delta rays, drift, avalanche SimHit WireHit AnalogSignal WireDigi Shape & sum (shares code) StripHit AnalogSignal StripDigi ComparatorDigi
Effects From Calibrations • Used: • Gains • Pedestal • Pedestal Width • Correlated Noise • Crosstalk • Bad Chambers • Not Used: • Bad Channels
Correlated Noise in Strips • 1st, 2nd, and 8th samples use pedestal width / 2 • Should hardcode a 25% correlation for nearest neighbors • Other samples use correlated noise from database
Crosstalk in Strips • Simulation models crosstalk as: • Constant times neighboring signal (resistive) • Constant times the slope of the neighboring signal (capacitive) • Crosstalk calibrations are measured as a linear fit: • Crosstalk fraction = m * (t-tpeak) + b • Reconstruction surprisingly insensitive to crosstalk 6
Raw Data Packing • Complex • Over 40 data structures • Significant changes between versions • Needs to be perfect • The Examiner module will drop an entire FED if any problems are seen with headers, wordcounts, CRCs
Plans • Queued for 3_5_X • Tweaked timing so that downstream products (RecHits and L1 trigger segments) are centered in BX. • Updated to newest packing format • Needed for data mixing • DataMixer code to merge strip signals • To do: • Validate crosstalk