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STAR-EMC Trigger. A. Vander Molen for the EMC Group. Requirements of EMC Trigger. Trigger on events with Jets Direct ’s Electrons High E t processes Neutral Energy Isospin Ratios Calibration and produce Luminosity bits. Signal Characteristics.
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STAR-EMC Trigger A. Vander Molen for the EMC Group
Requirements of EMC Trigger • Trigger on events with • Jets • Direct ’s • Electrons • High Etprocesses • Neutral Energy • Isospin Ratios • Calibration • and produce • Luminosity bits
Signal Characteristics • Jets - Energy concentrated in 0.8x0.8 Patches • Di-jets - High Et • Direct ‘s - Energy concentrated in single .05x.05 Towers • Di- ‘s - High Et • Electrons -Energy concentrated in single .05x.05 Tower • SMD insensitive to hadronic matter • High Et - Total Energy over threshold • Ratio of EMC to CTB
Input Signals To Level 0 • 300 6 bit Barrel PMT trigger towers (.2 x .2) • 300 6 bit Barrel PMT highest tower (.05 x .05)
Level 0 Functionality • Convert all energy to E - Transverse • Generate Etotal • Generate 1.0x0.8.0 non overlapping patches (Jet tower) • Compare Etotal to 3 thresholds • Compare Etotal to 3 thresholds (Luminosity) • Compare Jet tower to 3 thresholds • Compare High tower to 3 thresholds • Generate High tower to Trigger tower correlation.
Level 0 CTB/EMC Functionality • EMC/CTB energy/multiplicity ratio
Interim Output Bits • Total Etotal 3 bit(1 bit/threshold) • Jet tower 6 bits (2 bit counter/threshold) • High tower 6 bits (2 bit counter/threshold) • High /trigger tower 2 bits(2 bit counter) • Luminosity 3 bits Barrel (1 bit/threshold) • Patch energy 8 bits
Electronics • 35 DSM boards (30+4+1) • 2 VME crates with 18 slots • Modified DSMI boards • 12 twisted pair differential inputs(FEE output) • 128 TTL output (DSM input)
Algorithm • Layer 1 of DSM boards • Transform E to E transverse • High tower 3 thresholds • Trigger tower 3 thresholds • High tower/ Trigger tower • Partial Energy Sum • Output • Energy Sum 8 bits • High tower 3 bits • Trigger Tower 3 bits • Ratio 1bit
Algorithm - continued • Layer 2 of DSM boards • Form Jet patches • Jet thresholds • Partial Total Energy • Output • Energy Sum 8 bits • High tower 3 bits • Trigger Tower 3 bits • Ratio 1 bit • Jets 3 bits
Algorithm - continued • Layer 3 of DSM boards • Total Energy • Total Energy thresholds • Form Geometric Bit sums • Generate output bits • Output • Trigger bits
Day One Implementation • 10% of Detector or 30-40 12 bit inputs. • (5 +1 ) DSM boards
Level 1,2 and Level 3 • Level 1 Not implemented • Level 2 • Refined Jet finding • Overlapping patches • Geometric Considerations • SMD data • Level 3 • Full Tracking