1Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
CSC Trigger Primitives Test Beam Studies
Main Test Beam 2003 Goals:• Verify the peripheral crate electronics (mainly DMB/TMB) are
ready for production.
• Complete a trigger electronic chain test from CSCs all the way to the Track-Finder trigger.
Subsidiary Goals:• Find and fix hardware/firmware bugs and annoyances.
• Find and fix software bugs and annoyances.
• (Re-)demonstrate proper triggering and DAQ readout.
• Shake out new OO software package.
2Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Beam Test Setup
Peripheral Crate2 DMB, 2 TMB1 CCB, 1 MPC
FED crate 1 DDU
PC
TTC crate
DAQ Data
Trigger primitives
S1 S2 S3
beam
CSC 1 CSC 2
Track finder Crate
TRIDAS
3Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Beam Test Setup
/ From front
end cards
2 TMBs and DMBs
MPC
CCB + TTCRx
• 2 CSC’s, all on-chamber boards• Peripheral crate• Track Finder• CMS readout board• Up to 80K events read out in 2.6s
spill
4Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Typical Muon Event (CSC1 tilted)
5Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
2003 Test Beam Chronology• Phase I – structured beam
• May 23-June 1• ALCT timing tests• CLCT and TMB studies• High-rate tests
• Phase II – unstructured beam• June 13-28• CLCT and TMB studies• Low-rate and high-rate tests
• Phase III – additional structured beam• September 18-22• Trigger optical link data transmission tests (MPC to SRSP)
6Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Phase I Results• Optimal timing found• Fairly high efficiency (~98-99%) achieved• Peripheral crate system basically working as
desired• Chamber angle, HV, threshold scans
7Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Structure repeats during 2.6 s spill length
48 bunches25 ns bunch spacingbunch width 3-5 ns
SPS orbit period
1.2 s
23 s
2003 Synchronous Beam Structure
8Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Bunch Structure, ALCT Delay Tuning
BX efficiency vs. ALCT delay setting 0-31 ns
Chamber 1 Chamber 2
Expect muons in 48 out of 924 bx verified by CLCT bxn from data
9Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
BX Distributions With Optimal Anode Delays
Note logarithmic scale
Cathodes: • Data mostly in 3 bx
(no fine time-adjustment possible)
Anodes: • Data 98.7% in 1 bx
(after fine time-adjustment)
Chamber 1 Chamber 2
10Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
CLCT Positions• Relative position
of key half strip from CLCTs from chamber 2 vs. Chamber 1
• Note: Chamber 1 is vertically higher than Chamber 2 (thus the offset in position).
Zoom
11Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
LCT Efficiency vs. Comp. Thresh.• HV=3600v
12Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
LCT Efficiency vs. HV
13Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Trigger Rate Tests
Expected LCT rate at LHC < 25 KHz (ME1/1)
data consistent with dead-time = 225 ns
Chamber #1 CLCT
0
500
1,000
1,500
2,000
0 500 1,000 1,500 2,000 2,500 3,000
Beam Intensity (KHz)
CL
CT
Ra
te (
KH
z) SLHC (10xLHC) SLHC
(10xLHC)
14Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Number of LCTs (Run 529)
Cathodes show ~4% 0-LCT events
• Early run, before timing tuned
Anodes show ~10% 2-LCT events
15Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Look at 2-ALCT events
Differences:• Bunch crossing counter
• Wire group
16Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
An Event w/ 2 Chamber 1 ALCTs
• Anode hits satisfy 6-hit requirement in 2 adjacent key wire groups
17Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Patterns and Quality in ALCT and TMB Logic xxx__ ly 0 _xx__ ly 1 __x__ ly 2 __xx_ ly 3 __xxx ly 4 __xxx ly 5
ALCT Pattern
TMB Patterns
x___ x___ xx__ _x__ _xx_ __x_
pattern 1
_x__ _x__ _x__ _x__ __x_ __x_
pattern 2
x___ x___ xx__ _x__ _x__ _x__
pattern 3
_x__ _x__ _x__ _x__ _x__ _x__
pattern 4
__x_ __x_ _xx_ _x__ _x__ _x__
pattern 5
_x__ _x__ _x__ _x__ x___ x___
pattern 6
__x_ ly 0 __x_ ly 1 _xx_ ly 2 _x__ ly 3 xx__ ly 4 x___ ly 5
pattern 7
Patterns:
Qualities for ALCT and CLCT:Quality=3 6 layers in pattern
Quality=2 5 layers in pattern
Quality=1 4 layers in pattern
Quality=0 <=3 layers in pattern
18Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Half-/Di-Strip CLCT PatternsNominally phi_b=0, but small tilts, esp. chamber 2
19Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
CLCT Quality, Pattern vs. Phi_b
Phi_b (tilt)
Quality (layers)
Pattern
20Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Test Beam Periods 2&3• Timing-in procedures improved & documented• Very high efficiencies achieved
• Highest trigger efficiency of 99.9% required low rate (few kHz)
• 2-chamber “excellent event” (CFEB, CLCT, ALCT) efficiency limited to 99% due to CFEB timing
• Improved scans taken:• Angle scan
• HV scan
• Comparator threshold scan
• Pattern requirements scan
• Logic scope read out on most data
• True time history of LCTs read by SR/SP input FIFO (see Darin/Alexei talks).
21Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
CLCT Pattern RequirementsExample – “excellent event” (2xCFEB, 2xCLCT,
2xALCT) percentages:
Di-strip Pretrig. Layers
Half-strip Pretrig. Layers
Pattern Layers
Run # Excellent Event Eff.
(off) 4 1 1133 98.9%
4 4 1 1134 98.8%
3 3 1 1132 98.0%
3 3 3 1131 97.9%
4 4 4 1126 94.7%
(off) 4 4 1119 94.7%
(off) 3 3 1120 94.7%
(off) 2 2 1121 92.6%
22Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Digital Comparisons LCTs vs. Simulation• Simulation “DIGIs” start
from raw hit data• ORCA classes used
• Added modifications to reflect test beam TMB firmware (due to FPGA limitations)
• In principle, tests ALCT, CLCT, and TMB logic.
• So far, mainly a good debugging tool for simulation
• Present level of ALCT disagreement:
• ALCT Wire Group: 1.75%/1.99%
• ALCT Quality: 0.15%/0.41%
• CLCT disagreement ~10% (see plots on right)
23Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Comparison of LCTs to Simulation• ORCA simulation has some shortcomings and
needs updating:• Pretrigger # of layers is still hardcoded.
– Was varied during test beam data-taking
• No drift delay in ORCA after pretrigger – just uses any hits within 4 bx of some reference bx.
• ORCA logic selects highest quality only, doesn’t prefer half-strip patters to di-strip patterns as per hardware.
• Simplification for test beam TMB allows only 1 CLCT per CFEB
• These are being addressed right now.
24Endcap Muon meeting: CMU, Oct 19, 2003 J. Hauser UCLA
Comments on Results• Timing in the system takes effort but getting
easier (~2 weeks -> 1 week -> 2 days)• Almost everything can be done remotely with software.
• Procedures must really be streamlined to deal with 468 chambers…
• When timed in and experts are present:• Electronics hardware is reliable (nothing flaky).
• Data quality is terrific, esp. compared to other CMS subsystems…
• Trigger and readout efficiencies are very good.
• It will be hard work to streamline for 468 chamber operation…