CSC Digitization Rick Wilkinson 1

CSC design and readout Large chambers Wires groups:5 cm wide Cathode strips: 8-16 mm wide 3.3 m wire-group hits every 25 ns same information for trigger/offline Level-1 Trigger: half-strip hits every 25 ns HLT*/offline: 12-bit digitization every 50 ns *HLT – High Level Trigger 2

Code Structure SimHit WireHit StripHit AnalogSignal WireDigi StripDigi ComparatorDigi Ionize, Delta rays, drift, avalanche Shape & sum (shares code) 3

Effects From Calibrations Used: –Gains –Pedestal –Pedestal Width –Correlated Noise –Crosstalk –Bad Chambers Not Used: –Bad Channels 4

Correlated Noise in Strips 1 st, 2 nd, and 8 th samples use pedestal width /  2 –Should hardcode a 25% correlation for nearest neighbors Other samples use correlated noise from database 5

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 7

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 8