1 status of end-cap modules ● irradiated modules ● tracking with irradiated modules ● k5.1...
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Status of End-cap Modules
● Irradiated modules● Tracking with irradiated modules● K5.1 modules
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Status of Irradiated Modules
● 5 modules (K5.0) irradiated modules✔ Some at different doses (accidental)
● 2 modules (K5.1) being irradiated
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IV curves
● IV curves✔ Confirm that
May/June irradiation dose was half of the expected value
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Irradiation data
● Data corrected for calibration factors and temperature
0.00 1.50 3.000.005.00
10.0015.0020.0025.0030.0035.0040.0045.0050.00
Gain
K5-312
K5-308
K5-303
K5-310
Fluence
Gain
0.00 1.50 3.001000.00
1200.00
1400.00
1600.00
1800.00
2000.00
2200.00e- ENC
K5-312
K5-303
K5-308
K5-310
Fluence
e- E
NC
0.00 1.50 3.000.00
100.00
200.00
300.00
400.00
500.00
600.00Threshold Spread
K5-312
K5-303
K5-308
K5-310
Fluence
Th
rs.
Spr
ead
(e-
EN
C)
Back to FDR (k5-308) situation with fully irradiated modules
K5- 308 K5- 312Occup @ 1f C 2.30E-03 1.40E-03Min Thrs. (f C) 1.20 1.10
Source meass. needed for max. threshold for efficiency
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K5-312 .vs. K5-308
● K5-312, K5-308after full irradiation
● K5-312 shows some “timing” problems
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Test beam – Eff. vs Occup.
● K5-308, can operate within specs in a narrow threshold window.● K5-310,K5-312: received half of the dose. In specs.
K5-310 K5-312 K5-308
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Test Beam – Signal/noise
● K5-308, s/n is slightly higher than 8 at 500V● K5-310,K5-312: s/n flattens at ~350V with a value of ~11.
K5-310 K5-312 K5-308
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Tracking
● Tracking studies made with 3 irradiated end-cap modules:✔ 2 of them were not fully irradiated.✔ Efficiency is product of individual efficiencies✔ Det. Bias only affects efficiency✔ Number of planes decreases fake rate.
⇨ With 4 planes (barrel) fake rate is <10-4 for occupancies up to 5x10-3.
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K5.1 modules
● 4 modules have been built (2 with perfect chips,2 with 1ch dead chips)✔ K5-501,K5-503: Valencia✔ K5-502,K5-504: Geneva
● All off them showed “features” when tested in the boxes after construction.
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K5.1 Modules
● Plug & play in the system sector disk (all)✔ Decision is made to irradiate the modules with perfect chips.
● First suspicion: electrical versus optical readout✔ Optical readout works in the box✔ Redundant (electrical) readout works on the disk
● “Undo” any grounding “improvement” in the ST trying to make the modules fail (no way)
● Suddenly the modules start working properly in the box...✔ 2 more modules are being built to understand the problem
● Other issues:✔ A drop of an oil-like substance is found on top of a chip in one of the
modules. Could be removed✔ Oil-based, “micrometric” contamination found in 2 of the modules.
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K5.1 contamination
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Conclusions
● Need to “source” irradiated modules:✔ Noise figures comparable to 308 in July/August.✔ Charge and S/N ???
● Tracking...✔ Up to 5x10-3 noise occupancy can be tolerated in terms of fake rate
with 4 planes of modules....● K5.1
✔ 2 modules being irradiated✔ 2 more modules being built.✔ Total of 4 modules could soon be used in the ST